US20130327552A1 - Power tool having multiple operating modes - Google Patents

Abstract

A handheld power tool is configured to receive an input indicative of a clutch setting for an electronic clutch from the tool operator, where the clutch setting is selectable from a drill mode, an automated drive mode and one or more user-defined drive modes. Each of the user-defined drive modes specifies a different value of torque at which to interrupt transmission of torque to the output spindle. In an automated drive mode, the controller interrupt torque to the output spindle in an automated manner when a fastener being driven reaches a desired stopping position. In a selected one of the user-defined drive modes, the controller sets a value of a maximum current threshold in accordance with the selected one of the user-defined drive modes and interrupts torque to the output spindle when current measures exceeding the maximum current threshold.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Application No. 61/657,269, filed on Jun. 8, 2012. The entire disclosure of the above application is incorporated herein by reference.
FIELD
• The present disclosure relates to portable hand held power tools including drills and drill drivers.
BACKGROUND
• It is known to provide a power tool with switches, knobs, and other controls. For example, a power drill or driver typically includes a trigger that the user actuates to cause rotation of a tool held in a chuck. Power drills or drivers also typically include a forward/reverse selector switch located near the trigger that the user actuates to change a rotation direction of the tool. Some power drills or drivers also include a clutch control (e.g., a dial) that is used to change a clutch torque setting such that the amount of resistance necessary to stop rotation of the chuck can be set or changed by the user.
• Conventional power tool controls suffer from certain disadvantages. For example, conventional controls can be awkward to manipulate while holding the power tool. The user is often required to hold the tool with a first hand and set or change operating controls with a second hand, and controls may take up substantial space or be awkwardly located, thereby making setting or changing control operations difficult. Moreover, these power tools may have a manual only or an automatic only operated clutch, thereby limiting operational control of the clutch and tool.
• This section provides background information related to the present disclosure which is not necessarily prior art.
SUMMARY
• This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
• In one aspect of this disclosure, a method is provide for operating a power tool having an electric motor drivably connected to an output spindle. The tool is configured to receive an input indicative of a clutch setting for an electronic clutch form the tool operator, where the clutch setting is selectable from a drill mode and a drive mode. In a drill mode, torque applied to the output spindle is ignored; whereas, in the drive mode, the torque applied to the output spindle is monitored and interrupted in an automated manner by a controller when a fastener being driven reaches a desired stopping position.
• In other aspects of this disclosure, the clutch setting is selectable from a drill mode, an automated drive mode and one or more user-defined drive modes, where each of the user-defined drive modes specifies a different value of torque at which to interrupt transmission of torque to the output spindle. In an automated drive mode, the controller interrupt torque to the output spindle in an automated manner when a fastener being driven reaches a desired stopping position. In a selected one of the user-defined drive modes, the controller sets a value of a maximum current threshold in accordance with the selected one of the user-defined drive modes and interrupts torque to the output spindle when current measures exceeding the maximum current threshold.
• An improved technique for detecting when a fastener has reaches a desired stopping position is also presented. The improved techniques generally includes: sampling periodically current delivered to the electric motor; storing a sequence of current measures most recently sampled; and determining a slope for the sequence of current measures by way of linear regression. Transmission of torque to the output spindle can be interrupted based in part on the slope of the current measures.
• Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
• The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
• FIG. 1 is a front left perspective view of a drill/driver of the present disclosure;
• FIG. 2 is a partial cross sectional front left perspective view taken atsection2 ofFIG. 1;
• FIG. 3 is a front left perspective view of a rotary potentiometer and switch assembly of the present disclosure;
• FIG. 4 is a top left perspective view of the rotary potentiometer and switch assembly ofFIG. 3;
• FIG. 5 is a top plan view of the rotary potentiometer and switch assembly ofFIG. 3;
• FIG. 6 is a left side elevational view of the rotary potentiometer and switch assembly ofFIG. 3;
• FIG. 7 is a flow diagram defining a forward/reverse clutch operation using a rotary potentiometer/switch assembly of the present disclosure;
• FIG. 8 is a left rear elevational perspective view of the drill/driver ofFIG. 1;
• FIG. 9A is a flow diagram defining a battery state of charge operation of the present disclosure;
• FIG. 9B is a table providing exemplary battery voltages at various capacity levels associated with the flow diagram ofFIG. 9A;
• FIG. 10 is a current vs. time graph depicting a change in current rate during operation in a drive mode;
• FIG. 11A is a front left perspective view of the drill/driver ofFIG. 1;
• FIG. 11B is a top view of the drill/driver depicting an alternative display interface for selecting between a drill mode and a drive mode;
• FIG. 11C is an exploded view of the alternative display interface module;
• FIGS. 12A and 12B are first and second portions of a flow diagram of the operating steps differentiating the drill mode from the drive mode, including use of algorithms;
• FIG. 13 is a left side elevational view of the drill/driver ofFIG. 1 during installation of a fastener through two components;
• FIG. 14 is a top left perspective view of the drill/driver ofFIG. 1;
• FIG. 15 is a partial cross sectional left side elevational view of the drill/driver ofFIG. 13;
• FIG. 16 is a flow diagram of a timed operation mode of the drill driver ofFIG. 1;
• FIG. 17 is a voltage versus time graph identifying a current flow during timed operation mode;
• FIG. 18 is a left side perspective view of the drill/driver ofFIG. 1 during remote operation with a user interface device;
• FIG. 19 is a flow diagram of an initialization operation of the drill driver ofFIG. 1 for selection of an operating mode;
• FIG. 20 is a diagram of the electronic control system for the drill driver ofFIG. 1;
• FIG. 21 is a flow diagram of drill driver operation in a motor control mode;
• FIG. 22A is a flow diagram of LED illumination corresponding to selected clutch torque settings;
• FIG. 22B is a table of selected input level, torque level and corresponding LED display data corresponding to the clutch torque flow diagramFIG. 22A;
• FIG. 23 is a flow diagram for LED illumination indicated during each of a forward and a reverse clutch operation;
• FIG. 24 is a flowchart illustrating an improved technique for setting a fastener in a workpiece;
• FIGS. 25 and 26 are diagrams depicting an exemplary embodiment for controlling operation of the drill driver to set a fastener;
• FIG. 27 is a diagram depicting another exemplary embodiment for controller operation of the drill driver to set a fastener;
• FIG. 28 is a perspective view of a drill driver having an alternative display.
• Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
• Referring toFIG. 1, a portable hand-held power tool which in one form is adrill driver10 includes abody12 having ahandle14 shaped to be grasped in a single hand of a user, arechargeable battery pack16 that is releasably connected to abattery mounting portion18 ofbody12, and achuck20 having two or moreclutch jaws22 which are axially rotated with respect to arotational axis24. Aclutch sleeve26 is also rotatable with respect torotational axis24 that is used to manually open or closeclutch jaws22. While the following description is provided with reference to a drill driver, it is readily understood that some of the features set forth below are applicable to other types of power tools.
• A manually depressible and returnbiased trigger28 is provided to initiate and control operation ofdrill driver10.Trigger28 is operated by manually depressing in a trigger engagement direction “A” and returns in a trigger release direction “B” upon release.Trigger28 is provided in amotor housing30 that according to several aspects is divisible into individual halves, including a motor housingfirst half30aand a motor housingsecond half30bwhich can be made for example of molded polymeric material. Positioned adjacent to trigger28 is a rotary potentiometer/switch assembly32. Aportion33bof rotary potentiometer/switch assembly32 extends freely outwardly from bodysecond half30bon a second or left hand side ofbody12. Asimilar portion33a(shown in reference toFIG. 5) extends freely outwardly from bodyfirst half30aon a first or right hand side ofbody12. Rotary potentiometer/switch assembly32 provides several functions which will be described in reference to subsequent figures. Adisplay port80 is also provided withbody12 which will be described in greater detail in reference toFIG. 8.
• Referring toFIG. 2 and again toFIG. 1, with the motor housingsecond half30bremoved for clarity,drill driver10 further includes aDC motor34 and amotor transmission35, themotor34 operable using DC current frombattery pack16 and controlled bytrigger28.Motor34 andmotor transmission35 are mounted inmotor housing30 and are drivably connected via an output spindle (not shown) to chuck20 for rotation ofchuck20. It is readily understood that broader aspects of this disclosure are applicable to corded tool as well as battery powered tools.
• Rotary potentiometer/switch assembly32 includes arotary member36 in the shape of a circular disk whereinportion33bextending outward frombody12 is a portion ofrotary member36 extending freely outwardly with respect tobody12 on the left hand side ofbody12. The outwardly extendingportions33a,33bofrotary member36 allow manual rotation and a side-to-side displacement ofrotary member36 by the user ofdrill driver10 from either the right hand side or left hand side ofbody12.Rotary member36 is positioned in ahousing space38 ofmotor housing30 providing clearance for both axial rotation ofrotary member36, and side-to-side displacement ofrotary member36 in either a left hand or a right hand displacement such that rotary potentiometer/switch assembly32 performs at least dual functions as will be described in reference toFIGS. 3-6. According to further aspects,rotary member36 can be replaced by a sliding member, a rocking member, or other types in input components.
• A printed circuit board (PCB)40 is positioned inhandle14.PCB40 defines an electronic control circuit and includes multiple components including amicrocontroller42 such as a microchip, having a central processing unit (CPU) or the like for performing multiple functions ofdrill driver10, at least one electrically erasable programmable read-only memory (EEPROM) function providing storage of data or selected inputs from the user ofdrill driver10, and at least one memory device function for storing both temporarily and permanently saved data such as data lookup tables, torque values and the like for use bydrill driver10. According to other aspects (not shown),microcontroller42 can be replaced by separate components including a microprocessor, at least one EEPROM, and at least one memory device.
• Rotary member36 is rotatable with respect to a rotary member axis ofrotation43. Rotation ofrotary member36 can be in either a first rotational direction “C” or a second rotational direction “D” which is opposite to first rotational direction “C”. It is noted that the rotary member axis ofrotation43 can displace whenrotary member36 is moved in the side-to-side displacement described above and which will be described in greater detail in reference toFIG. 5.
• Referring toFIG. 3 and again toFIG. 2, the rotary potentiometer/switch assembly32 hasrotary member36 rotatably connected to anassembly platform44 such as a circuit board which is housed withinbody12. Aconnector46 is fixed toassembly platform44 providing for electrical communication betweenassembly platform44 and printedcircuit board40, thereby includingassembly platform44 with the electronic control circuit defined byPCB40.Assembly platform44 includes an assembly platformfirst end48 having afirst axle50 extending from a first side offirst end48 and asecond axle52 oppositely directed with respect to assembly platformfirst end48. First andsecond axles50,52 are coaxially aligned defining an axle axis ofrotation54. The first andsecond axles50,52 allow theassembly platform44 as a unit to rotate with respect to axle axis ofrotation54. Theassembly platform44 further includes an assembly platformsecond end56 having amount member58.Mount member58 provides attachment and support for each of a first biasingmember60 and an oppositely directed second biasingmember62.
• Referring toFIG. 4 and again toFIGS. 2 and 3, the first biasingmember60, which according to several aspects can be a compressible spring, contacts and is supported against a mount member first face64 ofmount member58. First biasingmember60 is shown in its normally extended, non-biased condition. From this position, first biasingmember60 is compressible in a first compression direction “E”. Thesecond biasing member62 is similar to first biasingmember60 and therefore provides a substantially mirror image configuration of a compressible spring which contacts and is supported against a mount member second face66 ofmount member58. From its normally non-biased position shown inFIG. 4, second biasingmember62 is elastically compressible in a second compression direction “F” which is oppositely oriented with respect to first compression direction “E”. During axial rotation ofassembly platform44 with respect to axle axis ofrotation54, either the first or the second biasingmember60,62 is elastically depressed against one of the motor housing first orsecond halves30a,30b. The biasing force generated by compression of either first or second biasingmember60,62 acts to return theassembly platform44 to a neutral position when the manual force applied to rotateassembly platform44 is released.
• Referring toFIG. 5 and again toFIGS. 2-4, as previously notedassembly platform44 is rotatable with respect to axle axis ofrotation54 usingfirst axle50 and second axle52 (not visible in this view). With theassembly platform44 positioned in a neutral position,rotary member36 is axially rotatable with respect to rotary member axis ofrotation43 to either increase or decrease an operating torque created as a torque limit command or signal by the rotational position ofrotary member36 and applied to chuck20.Rotary member36 can be rotated in each of a first rotational direction “G”, which is clockwise as viewed with respect toFIG. 5, or in a second rotational direction “H”, which is opposite with respect to first rotational direction “G” and is therefore counterclockwise as viewed inFIG. 5. Axial rotation ofrotary member36 can be used, for example, to predetermine a torque setting ofchuck20 between a minimum and a maximum predetermined torque value as the torque limit command. For example, rotation ofrotary member36 in the first rotational direction “G” can be used to increase the torque setting or torque limit command, and rotation ofrotary member36 in the opposite second rotational direction “H” can be used to reduce the torque setting or torque limit command.Rotary member36 can therefore act as a rotary potentiometer generating commands or signals transferred viaconnector46 toPCB40. The first andsecond portions33a,33bofrotary member36 that extend outwardly from first andsecond halves30a,30b(shown in phantom) ofbody12 are shown.
• With continuing reference toFIG. 5,assembly platform44 further includes mirror image switches which are actuated whenassembly platform44 is manually rotated with respect to axle axis ofrotation54. For example, when the operator applies a force torotary member36 in a first force acting direction “J”, rotation ofassembly platform44 with respect to axle axis ofrotation54 acts to elastically compress first biasingmember60 in the first compression direction “E” until afirst displacement member68 of a firstdirectional switch70 is depressed/closed. When the operator applies a force torotary member36 from a second force acting direction “K”, theassembly platform44 rotates with respect to axle axis ofrotation54 such that second biasingmember62 is elastically compressed in the second compression direction “F” until asecond displacement member72 of a seconddirectional switch74 is depressed/closed. When the force applied in either the first or second force acting directions “J”, “K” is removed, the biasing force of either of the first orsecond biasing members60,62 causes theassembly platform44 to return to its original or neutral position, opening either the first or the seconddirectional switch70,74. Circuits closed by operation of either the first or the seconddirectional switch70,74 generate signals or commands used to determine a rotational direction ofchuck20, for example by setting either a forward (clockwise) rotation or a reverse (counter clockwise) directional rotation. The “dual mode” of operation provided by rotary potentiometer/switch assembly32 in one aspect is first to control clutch torque and second to control the chuck rotation direction. The “dual mode” of operation can also include multiple variations of torque application, directional control, timed operation, clutch speed settings, motor current control, operation from data saved in memory from previous operations, and others as further defined herein.
• The electronic control provided bymicrocontroller42 and the electronic control circuit ofPCB40 determines multiple operations ofdrill driver10. As previously noted, when firstdirectional switch70 is closed, chuck20 will operate in a forward or clockwise operating rotational direction. In addition, by subsequent rotation ofrotary member36 following the actuation of firstdirectional switch70, additional modes of operation ofdrill driver10 can be selected, including selecting a speed setting ofmotor34, selecting an automatic torque cutout setting, selecting a speed control response, selecting a fastening seating algorithm, and additional modes which will be described later herein. If seconddirectional switch74 is closed, chuck20 will be rotated in a reverse or counter-clockwise direction of rotation and subsequent rotation ofrotary member36 can have similar control mode selection features for operation ofdrill driver10 in the reverse direction. In addition, the electronic control provided by operation ofrotary member36 and first and seconddirectional switches70,74 can also be used to customize the operation ofrotary member36 through a series of operations ofrotary member36 and trigger28 to suit either a left or right handed user ofdrill driver10.
• For example, once the user has set a left or right hand mode of operation, subsequent rotation ofrotary member36 can always result in a forward mode being selected such that the operation ofdrill driver10 for either a right or left handed operator becomes intuitive for the operator. An advantage of placingrotary member36 adjacent to handle14, where the control ofrotary member36 is achieved for example by the thumb of the operator, provides for one-handed operation ofdrill driver10, allowing control of multiple modes of operation in a one-handed operation. The same one-handed operation is also permitted by the rotational displacement provided by first andsecond axles50, ofassembly platform44 such that physical side-to-side rotational displacement ofassembly platform44 about the axle axis ofrotation54 provides additional functions for the accessible positions ofrotary member36.
• Referring toFIG. 6 and again toFIGS. 2-5, the various components ofassembly platform44 can be fixed. For example, first andsecond axles50,52 andmount member58 can be fixed using adhesives or integrally connected toassembly platform44 during a molding process, creatingassembly platform44. First and seconddirectional switches70,74 (only seconddirectional switch74 is clearly visible in this view) are also fixed toassembly platform44. Amount member75 fixed toassembly platform44 allows for axial rotation ofrotary member36. According to several aspects, aplanar surface76 is defined byassembly platform44 such that the components mounted toassembly platform44 are retained in the same relative positions during axial rotation ofrotary member36 and also during axial rotation ofassembly platform44. A plurality ofgrip slots78 can also be provided withrotary member36 to assist in the axial rotation ofrotary member36.Grip slots78 can also be positioned about the perimeter ofrotary member36 at locations corresponding to individual rotary positions that visually indicate to the operator the degree of rotation required to achieve a next torque setting ofdrill driver10.
• Referring toFIG. 7, operation of the rotary potentiometer/switch assembly32 is depicted in a flow diagram. In an initializingstep82, variables and hardware that may be in an off or standby mode are initialized. In a nexttrigger timing step83, a time period following initiation of trigger pull is measured to determine iftrigger28 has been depressed for a minimum or required time period. If following thetrigger timing step83 it is determined that the minimum required time of trigger pull has not been met, this step repeats itself until the required minimum time period has been met. If following thetrigger timing step83 the required minimum time of depression oftrigger28 has been met, a latchingstep84 is performed wherein the power supply to the motor is latched, thereby providing electrical power to the electrical components ofdrill driver10. Following latchingstep84, aread EEPROM step85 is performed wherein data saved in the EEPROM ofmicrocontroller42 is accessed to initialize mode selection and to illuminate appropriate ones of the first through sixth LEDs102-112. Followingread EEPROM step85, ashutdown check step86 is performed wherein it is determined whether any of a power off timeout has occurred, an under-voltage cutoff has occurred, or a high temperature cutoff has occurred. If none of the conditions are present as determined inshutdown check step86, a triggerposition determination step87 is performed wherein a trigger position ADC (analog-digital converter) is read to determine if it is greater than a predetermined start limit. If so,drill driver10 is positioned in motor control mode in amotor controlling step88. If the trigger position ADC reading is not greater than the predetermined start limits, a forwardwheel determining step89 is performed to determine ifrotary member36 has been rotated in a forward rotational direction. If so, in a checkforward mode step90, a determination is made ifdrill driver10 is already positioned in a forward operating mode. If not, drilldriver10 is returned to a previous forward mode in areturn step91. Ifdrill driver10 is already in the forward operating mode, a next mode is selected in a selectnext mode step92. Following either returnstep91 or selectnext mode step92, a settingstep93 is performed wherein the LEDs, an H-bridge forming a portion ofPCB40, and a maximum PWM (pulse width modulation) value are set. Following settingstep93, or if the forwardwheel determining step89 indicates thatrotary member36 has not been rotated in a forward rotating direction, a reversewheel determining step94 is performed. It is initially determined ifdrill driver10 is in a forward operating mode in a checkforward mode step95, and if the forward mode is indicated the current forward operating mode is stored in astore mode step96. Following either checkforward mode step95 orstore mode step96, a settingstep97 is performed which is similar to settingstep93 with the exception that the reverse mode is set in addition to setting the LEDs, the “H” bridge direction, and the maximum PWM. Returning to theshutdown check step86, if any of the power off timeout, under-voltage cutoff, or high temperature cutoff indicators is present, a save to EEPROMstep98 is performed wherein values presently set for operation ofdrill driver10 are saved to EEPROM ofmicrocontroller42. Following save toEEPROM step98, anunlatch step99 is performed wherein the power supply is unlatched.
• Referring toFIG. 8,display port80 can be provided on an upper surface ofmotor housing30 and extend across both first andsecond halves30a,30bofmotor housing30.Display port80 includes multiple bi-color light emitting diodes (LEDs) that are capable of displaying three colors, as two pure or primary colors plus a third color which is a mix of the two primary colors. Each LED color can therefore provide visual indication of multiple different operating modes ofdrill driver10. The multiple LEDs include a first, second, third, fourth, fifth, andsixth LED102,104,106,108,110,112, all positioned on anLED display screen100. For example, the LEDs ofdisplay port80 can represent functions including a live torque reading, the status ofbattery16, a direction of rotation ofchuck20, and a changing (increasing or decreasing) torque signal asrotary member36 is rotated.
• In one example, first through sixth LEDs102-112 can be used to indicate the status ofbattery16 as follows. Ifbattery16 is fully charged and therefore at maximum voltage potential, all of LEDs102-112 will be illuminated. Ifbattery16 is at its lowest voltage potential, onlyfirst LED102 will be illuminated. Successive ones of the LEDs, such as first, second andthird LEDs102,104,106, will be illuminated whenbattery16 is at a capacity greater than the minimum but less than the maximum. The color used for illumination of the LEDs, for example during the battery status display check, can be different from the color used for other mode checks. For example, the battery state of charge indication can illuminate the LEDs using a green color while torque indication can use a blue color.
• Referring toFIGS. 9A,9B and again toFIG. 8, the battery state of charge display ofdisplay port80 is depicted on a battery state of charge flow diagram113 with corresponding voltages provided in a table142 ofFIG. 9B. In an initialLED de-energizing step114, all of the LEDs102-112 are turned off. In anext reading step116, a stack voltage ofbattery16 is read. In a firstvoltage determination step118, if the battery voltage is above a predetermined value, for example 20.2 volts, all of the LEDs102-112 are turned on in aLED energizing step120. If, following the firstvoltage determination step118, the voltage ofbattery16 is less than 20.2 volts but greater than 19.7 volts, in a fiveLED energizing step124 LEDs102-110 are turned on. Following the secondvoltage determination step122, if the voltage ofbattery16 is less than 19.7 volts but greater than 19.2 volts, LEDs102-108 are turned on in a fourLED energizing step128. Following the thirdvoltage determination step126, if the voltage ofbattery16 is less than 19.2 volts but greater than 18.7 volts as determined in a fourthvoltage determination step130, LEDs102-106 are turned on in a threeLED energizing step132. Similarly, following fourthvoltage determination step130, if a voltage ofbattery16 is less than 18.7 volts but greater than 18.2 volts, in a fifthvoltage determination step134 LEDs102-104 are turned on in a twoLED energizing step136. Finally, in a sixthvoltage determination step138, if the voltage ofbattery16 is less than 18.2 volts but greater than 17.7 volts, onlyfirst LED102 is turned on in a oneLED energizing step140.
• The battery status check can be performed by the operator ofdrill driver10 any time operation ofdrill driver10 is initiated, and will repeat the steps noted above depending upon the voltage of the batterycells forming battery16. For the exemplary steps defined in battery state of charge flow diagram113, the voltage lookup table142 ofFIG. 9B, which can be saved for example in the memory device/function provided withmicrocontroller42 shown and described in reference toFIG. 2, can be accessed for determining the number of LEDs which will be illuminated based on multiple ranges of battery voltages that are measured. It is noted the values identified in voltage lookup table142 can vary depending upon the voltage and number of cells provided bybattery16.
• Additional modes of operation fordrill driver10 can be displayed ondisplay port80 as follows. For example, either forward or reverse direction of operation forchuck20 can be indicated as follows. When the forward operating mode is selected, first, fifth, andsixth LEDs102,110,112 will be illuminated. When a reverse or counterclockwise rotation ofchuck20 is selected, fourth, fifth, andsixth LEDs108,110,112 will be illuminated. The color selected for indication of rotational direction can vary from the color selected for the battery status check. For example, the color indicated by the LEDs during indication of the rotational direction can be blue or a combination color of blue/green. Similar to the indication provided for the battery status check, a live torque reading selected during rotation ofrotary member36 will illuminate either one or multiple successive ones of the LEDs depending upon the torque level selected. For example, at a minimum torque level onlyfirst LED102 will be illuminated. At a maximum torque level all six of the LEDs102-112 will be illuminated. Individual ones of the LEDs will successively illuminate asrotary member36 is axially rotated between the minimum and the maximum torque command settings. Oppositely, the number of LEDs illuminated will reduce successively asrotary member36 is oppositely rotated, indicating a change in torque setting from the maximum toward the minimum torque command setting. When there are more settings than the number of LEDs available, combination colored LEDs can be illuminated such as blue/green. The LEDs ofdisplay port80 will also perform additional functions related to operation ofchuck20, which will be described in greater detail with reference to clutch operating modes to be further described herein.
• In another aspect of this disclosure, thedrill driver10 is configured to operate in different modes. For example, thedrill driver10 may provide an input component (e.g., rotary member36) that enables the tool operator to select a clutch setting for an electronic clutch. In one embodiment, the operator selects between a drill mode and a drive mode. In a drill mode, the amount of torque applied to the output spindle is ignored and transmission of torque is not interrupted by thecontroller42 during tool operation; whereas, in a drive mode, torque applied to the output spindle is monitored by thecontroller42 during tool operation. Thecontroller42 may in turn interrupt transmission of torque to the output spindle under certain tool conditions. For example, the controller may determine when a fastener being driven by the tool reaches a desired stopping position (e.g. flush with the workpiece) and terminate operation of the tool in response thereto without user intervention. It is readily understood that the selected clutch setting can be implemented by thecontroller42 with or without the use of a mechanical clutch. That is, in some embodiments, thedrill driver10 does not include a mechanical clutch.
• Referring toFIG. 11A,drill driver10 can include individual switches for operator selection between either a drill mode or a drive mode. Adrill selector switch170 is depressed when drill operating mode is desired. Conversely, adrive selector switch172 is depressed when drive operating mode is desired. The drill and drive operating modes are both operable withdrill driver10 regardless of the rotating direction ofchuck20. For example, operation in both the drill mode and drive mode are possible in a clockwise or forwardrotational direction174 and also in a counter clockwise or reverserotational direction176 ofchuck20. It is further noted that the selected one of eitherdrill selector switch170 or driveselector switch172 may illuminate upon depression by the user. This provides further visual indication of the mode selected by the user.
• Drill selector switch170 and driveselector switch172 may be actuated in different sequences to activate other tool operating modes. For example, thedrive selector switch172 may be pushed and held for a fixed period of time (e.g., 0.15 sec) to activate a high torque drive mode; whereas, pushing thedriver selector switch172 twice in the fixed period of time may activate a low torque drive mode. To indicate the different drive modes, thedriver selector switch172 may be lit steady when in the high torque drive mode and blinking when in the low torque drive mode. These two sequences are merely illustrative and other combinations of sequences are envisioned to activate these or other tool operating modes.
• FIG. 11B depicts analternative display interface1100 for selecting between a drill mode and a drive mode. In this embodiment, the buttons for selecting the operating mode are integrated into the top surface of the drill driver housing. Adrill icon1102 is used to represent the drill mode; whereas, ascrew icon1104 is used to represent the drive mode although other types of indicia may be used to represent either of these two operating modes. Once selected by the tool operator, the mode is activated (i.e., a signal is sent from the button to the controller) and an LED behind the button is lit to indicate which operating mode has been selected. The LED lights the icon which remains lit until the operating mode is changed, the tool becomes inactive or is otherwise powered down. The display interface may also includeLEDs1106 for indicating the state of charge of the battery in a similar manner as described above.
• An exemplary construct for the display interface is further illustrated inFIG. 11C. The display interface module is comprised of aplastic carrier1112, aflexible circuit board1113, and atranslucent rubber pad1114. Thecarrier1112 serves to hold the assembly together and attaches to the top of the housing. Thecircuit board1113 supports the switches and LEDs and is sandwiched between therubber pad1114 and thecarrier1112. The rubber pad is painted black and laser etched to form the icon shapes thereon.
• Referring toFIGS. 12A and 12B and again toFIG. 11, a drill/drive mode flow diagram177 defines steps taken by the control circuit ofdrill driver10 distinguishing between adrill mode180 and adrive mode182. In an initialcheck mode step178, the status ofdrill selector switch170 and/or driveselector switch172 is checked to determine which input is received by the user. If thecheck mode step178 indicates thatdrill mode180 is selected, a trigger actuationfirst function184 is initiated whentrigger28 is depressed. Following trigger actuationfirst function184, amotor start step186 is performed, thereby initiating operation ofmotor34. During operation of themotor34, an over-current check step is performed to determine ifmotor34 is operating above a predetermined maximum current setting. If the over-current indication is present from motorover-current check188, an overcurrent flag190 is initiated followed by astop motor step192 where electrical power tomotor34 is isolated. A drill drivemode return step194 is then performed wherein continued operation ofmotor34 is permitted after the user releases trigger28. Returning to the motorover-current check188, if an over-current condition is not sensed during the motorover-current check188, continued operation ofmotor34 is permitted.
• With continuing reference to drill/drive mode flow diagram177, whendriver selector switch172 is depressed by the user and drivemode182 is entered, a check is performed to determine if anauto seating flag196 is indicated. If theauto seating flag196 is not present, the following step determines if a timedoperating system flag198 is present. If the timedoperating system flag198 is present, in a next duty cycle setting step200 a timed operating duty cycle is set. Followingstep200,motor34 is turned on for a predetermined time period such as 200 ms (milliseconds) in atimed operating step202. Followingtimed operating step202, in a seating/timed operatingflag indication step204, the control system identifies if both an auto seating flag and a timed operating flag are indicated. If both the auto seating flag and timed operatingflag indication step204 are indicated, operation ofmotor34 is stopped in a stopmotor running step206.
• Returning to timedoperating system flag198, if the flag is not present, a trigger activationsecond function208 is performed which initiates operation ofmotor34 in a timed turn onmotor start210. Following this and similar to motorover-current check188, a motorover-current check212 is performed. If an over-current condition is not indicated, a first routine214 algorithm is actuated followed by a selection “on”check216. If the selection “on”check216 is negative, asecond torque routine218 algorithm is run, following which if a positive indication is present, returns to the seating/timed operating flag indication; and if negative, returns to thereturn step194. If the selection “on” check performed atstep216 is positive, a third routine220 algorithm is run which if positive thereafter returns to seating/timed operatingflag indication step204 and, if negative, returns to returnstep194.
• In some embodiments, the drive mode may divided into an automated drive mode and one or more user-defined drive modes, where each of the user-defined drive modes specify a different value of torque at which to interrupt transmission of torque to the output spindle. In the automated drive mode, the controller monitors the current being delivered to the motor and interrupts torque to the output spindle in response to the rate of change of current measures. Various techniques for monitoring and interrupting torque in an automated manner are known in the art, including techniques to setting a fastener in a workpiece, and fall within the broader aspects of the disclosure. An improved technique for detecting when a fastener reaches a desired stopping position is further described below. In such embodiments, it is readily understood that the input component may be configured for selection amongst a drill mode, an automated drive mode and one or more user-defined drive modes.
• Referring toFIG. 10 and again toFIGS. 1 and 2, a current versustime graph144 defines a typical motor current draw during operation to install a fastener usingdrill driver10. Initially, an inrush current146 briefly peaks prior to the current draw continuing at a low rate of change (LROC) current148. LROC current148 corresponds to a body of a fastener such as a screw penetrating a material such as wood at a constant speed. At the time when a head of the fastener contacts and begins to enter the wood, the current draw changes to a high rate of change (HROC) current150 for a brief period of time until acurrent plateau152 is reached, defining when the fastener head is fully embedded into the wood. As is known, the level of current draw is proportional to the torque created bymotor34.
• In a selected one of the user-defined drive modes, the controller sets a value of a maximum current threshold in accordance with the selected one of the user-defined drive modes and interrupts torque to the output spindle in response to the current measures exceeding the maximum current threshold. For example, the user selects one of the user-defined drives modes as the desired clutch setting using, forexample rotary member36.Current levels154 designated as “a”, “b”, “c”, “d”, “e”, “f” correlate to the plurality of predefined torque levels designated as “1”, “2”, “3”, “4”, “5”, “6”, respectively. During tool operation, thecontroller42 will act to terminate rotation of the chuck when the current monitored by thecontroller42 exceeds the current level associated with the selected user-defined drive mode (i.e., torque setting). The advantage of providing both types of drive modes (i.e., control techniques) withindrill driver10 includes the use ofcurrent level increments154 which, based on prior operator experience, may indicate an acceptable predetermined torque setting for operation ofchuck20 in a specific material. Where the user may not be familiar with the amount of fastener headset in a particular material and/or with respect to a particular sized fastener, the automatic analysis system can be selected, providing for acceptable setting of the fastener which may occur in-between individual ones of thecurrent level increments154.
• FIG. 24 illustrates an improved technique for controlling operation of the drill driver when driving a fastener. Briefly, the current delivered to the electric motor is sampled periodically at502 by the controller of the drill driver. The current measures most recently sampled by the controller are stored at504 in a memory of the drill driver. From the most recently sampled current measures, a slope for the current measures is determined at506 by way of linear regression. Linear regression is used because it has a better frequency response making it more immune to noise as compared to conventional computation methods. When a fastener being driven by the drill driver reaches a desired stopping position, torque transmitted to the output shaft is interrupted at508 by the controller. The desired stopping position is determined based in part on the slope of the current measures as will be further described below.
• FIGS. 25 and 26 further illustrating an automated technique for setting a fastener in a workpiece. Current delivered to the electric motor is sampled periodically by the controller of the drill driver. In an example embodiment, the controller can ignore current samples captured during an inrush current period (e.g., 180 ms after trigger pull). Whenever there is a change in the trigger position (i.e., change in PWM duty cycle), the controller will stop sampling the current until the inrush current period has lapsed. In some embodiments, the automated technique is implemented by the controller regardless of the position of the trigger switch. In other embodiments, the automated technique is only implemented by the controller when the trigger position exceeds a predefined position threshold (e.g., 90%). Below this position threshold, the tool operates at lower speeds, thereby enabling the tool operator to set the fastener to the desired position without the need for the automated technique.
• Current measures may be digitally filtered before computing the current change rate. In an example embodiment, current is sampled in 15 milliseconds intervals. During each interval, the controller will acquire ten current measures as indicated at560 and compute an average from the ten measures although more or less measures may be acquired during each interval. The average for a given interval may be considered one current sample and stored in an array of current samples indicated at562 inFIG. 26, where the array of current samples stores a fixed number (e.g., four) of the most recently computed values. The controller will then compute an average from the current samples in the array of current samples. The average for the values in the array of current samples is in turn stored in a second array as indicated at564 inFIG. 26, where the second array also stores a fixed number (e.g., five) of the most recently computed averages. These averaged current measures can then be used to determine the rate of current change. Other techniques for digitally filtering the current measures are also contemplated by this disclosure.
• With continued reference toFIG. 25, the slope of the current is determined at524 from the digitally filtered current measures. In an example embodiment, a linear regression analysis is used to compute the slope. In a scatter plot, the best fit line of the scatter data is defined by the equation y=a+bx, where the slope of the best fit line can be defined as
• $b=\frac{\sum \mathrm{xy}-\left(\sum x\sum y\right)/n}{\sum x^2-{\left(\sum x\right)}^2/n},$
• where n is the number of data points. The intercept will be ignored in this disclosure. For illustration purposes, assume data scatter plot with current values for y of [506,670,700,820,890] corresponding to sample values of [1, 2, 3, 4, 5], such that n=5. Using linear regression, the slope b of the best fit line is equal to 91.8. While a simple linear regression technique has been explained, other linear regression techniques are also contemplated by this disclosure.
• Slope of the current measures may be used as the primary indicator for when the fastener has been set at a proper depth in the workpiece. Particularly, by using the slope of the current, the tool is able to determine when the tool is in the HROC (of current) area shown in the graph ofFIG. 10. In the example embodiment, a slope counter is maintained by the controller. The current slope is compared at524 to a minimum slope threshold. For example, the minimum slope threshold may be set to a value of 40. This value may be set such that slope values exceeding the minimum slope threshold are indicative of theHROC150 range shown inFIG. 10. The slope threshold value may be derived empirically for different tools and may be adjusted according to the sampling time, motor attributes and other system parameters. In embodiments where the automated technique is implemented by the controller only when the trigger position exceeds a predefined position threshold, minor variations in trigger position (e.g., 10% from a baseline position) can be ignored once the current slope exceeds the minimum slope threshold and until such time as the fastener has been set and the torque to the output spindle is interrupted.
• The slope counter is adjusted in accordance with the comparison of the current slope to the minimum slope threshold. The slope counter is incremented by one when the computed slope exceeds the minimum slope threshold as indicated at536. Conversely, the slope counter is decremented by one when the computed slope is less than or equals the minimum slope threshold as indicated at532. When the slope is less than or equal to the minimum slope threshold, the value of the current slope is also set to zero as indicated at528. In the event the slope counter is equal to zero, the slope counter is not decremented further and the slope counter remains at zero as indicated at534. Following each adjustment, the value of the slope counter is stored in an array of slope counts as indicated at566 inFIG. 26, where the array of slope counts stores a fixed number (e.g., five) of the most recent slope count values.
• Next, the slope counts are evaluated at546 in relation to a fastener criteria. The fastener criteria atstep546 includes both a setting criteria, which is indicative of a desired stopping position for the fastener being driven by the tool, and a default criteria. The setting criteria and default criteria may be used together, as shown in546 ofFIG. 25, or only one of the criteria may be used. The setting criteria will be described first. In the setting criteria a fastener is assumed to have reached a desired stopping position when the slope counts increase over a series of values stored in the array of slope counts, where the series of values may be less than or equal to the total number of values stored in the entire array. In this example, each slope count value in the array is compared to an adjacent slope count value starting with the oldest value. The setting criteria is met when each value in the array is less than the adjacent value as compared from oldest value to the most recent value. For example, if the array is designed to hold five slope count values (SC1 through SC5), the setting criteria may be met when the consecutive count values are each increasing—i.e., SC1<SC2<SC3<SC4<SC5. In other words, the setting criteria is satisfied when the controller detects five successive computer slope values greater than the predetermined minimum slope threshold.
• As noted above, the setting criteria may not use the entire array of values. For example, the array may be designed to hold five slope count values, but the setting criteria may be set such that an increase of counts over a series of four values (e.g. SC2<SC3<SC4<SC5) is sufficient. Other variations regarding the particular number of counts required are also contemplated.
• The fastening criteria evaluated atstep546 may also include a default criteria. In some instances, the setting criteria described above with respect toFIGS. 25 and 26 may fail to trigger due to, for example, an anomaly reading or variations in a workpiece which result in the controller failing to detect the occurrence of the above-described setting criteria. In that case, there may be an additional criteria serving as a default criteria. In the default criteria, a fastener is assumed to have reached, or passed, a desired stopping position when the slope count peaks within a series of values stored in the array. In other words, if after detecting successive slope values that exceed the minimum slope threshold, the controller now detects successive slope values less than the minimum slope threshold, it is apparent the above-described setting criteria will not be met.
• As with the setting criteria, the series of values may be less than or equal to the number of values stored in the entire array. In this example, slope count values in the array are again compared to each other. The default criteria is met when the slope count values in the array increase from the oldest value to an intermediate peak value and then decrease from the intermediate peak value to the most recent value. For example, the default criteria may be met if SC1<SC2<SC3>SC4>SC5. Of course, other particular default criteria may be used. For example, the default criteria may require more successive increases or more successive declines than that provided in the example above (e.g., SC1<SC2<SC3<SC4>SC5>SC6>SC7; or SC1<SC2>SC3>SC4; etc.). In this embodiment shown inFIG. 25, the setting criteria and default criteria are used together. However, in an alternative embodiment, each may be used alone. Other types of setting and default criteria are also contemplated by this disclosure.
• Torque transmitted to the output spindle is interrupted at548 when the slope counts meet the setting criteria or default criteria; otherwise, tool operation continues as indicated at550. Torque may be interrupted in one or more different ways including but not limited to interrupting power to the motor, reducing power to the motor, actively braking the motor or actuating a mechanical clutch interposed between the motor and the output spindle. In one example embodiment, the torque is interrupted by braking the motor, thereby setting the fastener at the desired position. To simulate the electronic clutching function, the user may be subsequently provided with haptic feedback. By driving the motor back and forth quickly between clockwise and counter-clockwise, the motor can be used to generate a vibration of the housing which is perceptible to the tool operator. The magnitude of a vibration is dictated by a ratio of on time to off time; whereas, the frequency of a vibration is dictated by the time span between vibrations. The duty cycle of the signal delivered to the motor is set (e.g., 10%) so that the signal does not cause the chuck to rotate. Operation of the tool is terminated after providing haptic feedback for a short period of time. It is to be understood that only the relevant steps of the technique are discussed in relation toFIG. 25, but that other software-implemented instructions may be needed to implement the technique within the overall operation of the tool.
• FIG. 27 illustrates an additional technique for controlling operation of the drill driver when driving a fastener. Current delivered to the electric motor can be sampled and filtered at582 by the controller in the same manner as described above in relation toFIG. 25. Likewise, the slope of the current samples can be determined at584 in the manner described above.
• In this technique, motor speed is used as a secondary check on whether to interrupt transmission of torque to the output spindle but only when the current slope exceeds a minimum slope threshold. Accordingly, the current slope is compared at586 to a minimum slope threshold (e.g., with a value of 40). The secondary check proceeds at588 when the current slope exceeds the minimum slope threshold; otherwise, processing continues with subsequent current sample as indicated at582.
• To perform the secondary check, motor speed is captured at588. In one example embodiment, motor speed may be captured by a Hall effect sensor disposed adjacent to or integrated with the electric motor. Output from the sensor is provided to the controller. Other types of speed sensors are also contemplated by this disclosure.
• In the example embodiment, the controller maintains a variable or flag (i.e., Ref_RPM_Capture) to track when the current slope exceeds the minimum slope threshold. The flag is initially set to false and thereafter remains false while the present slope is less than the minimum slope threshold. At the first occurrence of the current slope exceeding the minimum slope threshold, the flag is false and the controller will set a reference motor speed equal to the present motor speed at592. The reference motor speed is used to evaluate the magnitude of decrease in motor speed. In addition, the flag is set to true at593 and will remain set to true until the current slope is less than the minimum slope threshold. For subsequent and consecutive occurrences of the current slope exceeding the minimum slope threshold, the flag remains set to true and reference speed is not reset. In this way, the flag (when set to true) indicates that preceding slope values have exceeded the minimum slope threshold.
• Next, the present speed is compared at594 to the reference speed. When the motor is slowing down (i.e., the reference speed exceeds the present speed), a further determination is made as to the size of the decrease. More specifically, a difference is computed at595 between the reference speed and the present motor speed. A difference threshold is also set at596 to be a predefined percentage (e.g., 5%) of the reference speed. The predefined percentage can be derived empirically and may vary for different tool types. The difference is then compared at597 to the difference threshold. Processing of subsequent current sample continues until the difference between the reference speed and the present speed exceeds the difference threshold as indicated at597. Once the difference between the reference speed and the present speed exceeds the difference threshold (and while the motor speed is decreasing), transmission of torque to the output spindle is interrupted at598. It is to be understood that only the relevant steps of the technique are discussed in relation toFIG. 25, but that other software-implemented instructions may be needed to implement the technique within the overall operation of the tool. Furthermore, the secondary check described above in relation toFIG. 27 is intended to work cooperatively (e.g., in parallel with) the technique described inFIGS. 25 and 26. It is also envisioned that this technique may be implemented independent from the technique described inFIGS. 25 and 26 as a method for automatically setting a fastener in a workpiece.
• Referring toFIG. 13 and again toFIGS. 1-6, when the user places thedrill driver10 in a clutch mode by manual rotation or operation of therotary member36 of rotary potentiometer/switch assembly32, and positions a tool such as asetting tool222 inclutch jaws22 ofchuck20, afirst fastener224 can be driven into first andsecond components226,227 to join the first andsecond components226,227. Subsequent operation oftrigger28 permits installation offirst fastener224 to a desired depth or degree of head seating for afastener head228 in relation to acomponent surface230 offirst component226. Because different screws have different characteristics, thedrill driver10 may enable the user to rough tune the fastener setting algorithm. For example, the current change rate threshold for a shorter screw may be lower than for a longer screw. To accommodate such differences, thedrill driver10 may provide two or more different user-actuated buttons that allow the user to tune the fastener setting algorithm. Continuing with the example above, one button may be provided to a shorter screw and one button may be provided for a longer screw. The current change rate threshold may be adjusted depending upon which button is actuated by the tool operator before an installation operation. It is readily understood that other parameters of the fastener setting algorithm or the tool (e.g., motor speed) may be adjusted in accordance with button actuation. Moreover, more or less buttons may be provided to accommodate different fastener characteristics or installation conditions.
• After completing installation offirst fastener224 such thatfastener head228contacts component surface230, it is often desirable to install a second or more fasteners to couple the first andsecond components226,227. Referring toFIG. 14 and again toFIGS. 12 and 13,drill driver10 can further include acontrol feature zone232 positioned, for example, at an upper facing surface ofmotor housing30.Control feature zone232 can include a plus (+)button234 and a minus (−)button236, as well as amemory store button238. After completing installation offirst fastener224, the user can press thememory store button238 to record an amperage draw that was required to seatfirst fastener224.
• Referring toFIG. 15 and again toFIGS. 1-2 and12-14, to install a second orsubsequent fastener224′, the user again presses thememory store button238 and actuates trigger28 to begin installation ofsecond fastener224′. The electronic control circuit ofPCB40 senses when the current draw that equals the current draw stored in the memory feature ofmicrocontroller42 is again reached during the installation offastener224′ and provides feedback to the user thatfastener224′ has seated in a similar manner asfirst fastener224. As previously noted, the current draw for installation of each of thefasteners224,224′ can be equated to a torque force required to drive the fastener. After the control circuit identifies thatfastener224,224′ is nearly seated based on the torque level sensed, the control circuit can vary the feedback to allow the user better control in stopping installation offastener224′ at the appropriate time and/or depth.
• The feedback provided to the user can be manipulated as follows. First, the output ofmotor34 can be stopped. Second, the speed ofmotor34 can be reduced. For example, the speed ofmotor34 can be reduced from approximately 600 rpm to approximately 200 rpm. This reduction in operating speed provides the user with visible feedback on the rate at which the fastener is being installed and provides additional time for the user to respond to howfar fastener224′ is being set into the first andsecond components226,227. Third, operation ofmotor34 can be ratcheted, for example by pulsingmotor34 on and off to provide discreet, small rotations of thefastener224′. This acts to slow down the average rotation speed ofchuck20, providing the user more control in setting the depth of penetration offastener224′. This could also function as an indication to the user that fastener installation is nearly complete and that thedrill driver10 has changed operating mode. In addition, ratcheting ofmotor34 also provides a sensation to the user similar to a mechanical clutch operation. Fourth, the varied output ofmotor34 from the above second and third operations can continue indefinitely or could continue for a fixed period of time and then stop. For example, the varied output ofmotor34 can continue until the user releases trigger28.
• With continuing reference toFIG. 14, in addition to the memory storage feature provided bymemory store button238, the user can use either theplus button234 or theminus button236 to fine tune a current draw limit in response to slight variations in either the fastener and/or the first orsecond component226,227. For example, if the user identifies that the amperage draw saved usingmemory store button238 after installation of thefirst fastener224 does not seat thefastener head228 ofsecond fastener224′ to an acceptable degree, the user can press theplus button234 to incrementally increase a cutout level of current load provided tomotor34. Similarly, but to an opposite extent, theminus button236 can be depressed to incrementally decrease the cutout level of current load. The features provided byplus button234, minusbutton236, andmemory store button238 are available in either drill or drive mode. These features allow the user to fine tune the operation ofdrill driver10 over a wide variety of materials, such as wood, plywood, particle board, plastics, metal, and the like, for which universal limits cannot be established.
• Referring again toFIGS. 12 and 14 as well as toFIGS. 1 and 2, in the event that operation ofmotor34 stops beforefastener head228 is completely engaged or parallel with respect tocomponent surface230, a timed operation mode is available to complete the installation offastener224 which provides an automatic period of operating time formotor34, thereby eliminating the need for the user to estimate the time or degree of rotation ofchuck20 to achieve full setting offastener224. When operation ofmotor34 ceases and the user releases trigger28, if the user visually recognizes that additional displacement offastener224 is required, and if the user subsequently depressestrigger28 within a predetermined time period after themotor34 has ceased operation, a timed operation mode is automatically engaged. The predetermined time period for initiation of the timed operation mode can be varied, but can be set, for example, at a period of time of approximately one second. Therefore, if the user recognizes that additional driving force is required to seatfastener224′ and again depressestrigger28 within approximately one second of the stop ofmotor34,motor34 is again energized to rotatechuck20 for a period of time approximating 200 ms ofchuck20 rotation. If the first operation in timed operation mode is not sufficient to fully seatfastener224, and the user releases trigger28 and again depressestrigger28 within approximately one second, a second or subsequent timed operation mode operation of approximately 200 ms will occur. The number of timed operation mode operations is not limited; therefore, the user can continue in this mode provided thattrigger28 is depressed within the minimum time period required. The timed operation mode will time-out if the user does not again depresstrigger28 within the predetermined time period, such as the exemplary one second time period described above. Following the time-out of the timed operation mode operation, thedrill driver10 will return to normal or the previous operating mode based on the parameters previously set by the user.
• Referring toFIG. 16 and again toFIGS. 12,14, and1-2, a timed operation mode flowchart identifies the various steps of operation of the electronic control circuit ofdrill driver10 providing for timed operation mode control. Initially, withdrill driver10 in drive mode, when the user releases trigger28 the control circuit searches for a timedoperation flag242. If the timedoperation flag242 is present, indicating that the user hasre-depressed trigger28 within a predetermined time period (for example 1 second), a timed operation duty cycle setstep244 is performed which subsequently directs, via a motor turn onstep246,motor34 to energize for a predetermined time period (for example 200 ms) ofchuck20 rotation. Asmotor34 operates in the timed operation mode, following indication by a counter that timed operation has been completed, in astop motor step248motor34 is de-energized. Aftermotor34 is de-energized, an increase switchhold counter step250 initiates, which will allow further operation in the timed operation mode iftrigger28 is again depressed within the predetermined time period. In aswitch check step252, a check is performed to identify if an analog digital converter (ADC) switch controlled bytrigger28 is still closed while an additional increase switchhold counter step250 is performed. If theswitch check step252 indicates that thetrigger28 has been released, afirst comparison step254 is performed wherein a switch hold counter is compared to a normal hold counter to determine if the switch hold counter is less than the normal hold counter. If the switch hold counter infirst comparison step254 is not less than the normal hold counter, a subsequentsecond comparison step256 is performed wherein it is determined if the switch hold counter is greater than the normal hold counter. If, as a result of the second comparison step, the switch hold counter is not determined to be greater than the normal hold counter, the timed operation mode is ended. Returning to the timedoperation flag242 initially queried at the start of the timed operation mode, if timedoperation flag242 is not present, the timed operation mode cannot be initiated.
• Returning to thefirst comparison step254, if the switch hold counter is less than the normal hold counter, adecrease counter step258 is performed wherein the timed operation time delay counter is decreased. Returning to thesecond comparison step256, if the switch hold counter is greater than the normal hold counter, anincrease counter step260 is performed wherein the timed operation time delay counter is increased. Following either thedecrease counter step258 or theincrease counter step260, the timed operation mode is timed-out.
• Referring toFIG. 17 and again toFIG. 16, a voltage versus time graph262 identifies the current draw at various voltages over time provided for operation ofmotor34 in the timed operation mode.
• Ifdrill driver10 is preset to operate in an automatic operating mode, the timed operation mode can be automatically induced when the electronic control system identifies thatmotor34 has stopped rotation, for example due to either the maximum current or torque setting being reached, while the user continues to depresstrigger28. After the determination that motor34 has stopped for a predetermined period of time whiletrigger28 is still depressed, the timed operation mode automatically begins and will rotatemotor34 and chuck20 for approximately 200 ms. The predetermined time period for automatic initiation of the timed operation mode can also be for example one second, or set to any other desired time period.
• Ifdrill driver10 is set to operate in the manual mode and the rotary potentiometer/switch assembly32 is used to predetermine or preset an operating torque via a torque command forchuck20,motor34 will stop when the predetermined torque setting is reached. If the user releases trigger28 at this time, and then re-depresses trigger28 within a predetermined period of time, a last saved high current level required to fully seat a fastener, saved for example in the EEPROM or memory device/function ofmicrocontroller42, will be automatically reapplied, thereby further rotatingchuck20 until the high current level last saved in memory is achieved. This permits a combination of a manual and an automatic operation ofdrill driver10 such that the predetermined or preset torque limits manually entered by the user can be supplemented automatically by a current level saved in the memory corresponding to a fully set fastener position.
• Referring toFIG. 18 and again toFIGS. 1 and 2, information stored in any of the various memory devices/functions ofdrill driver10 can be supplemented by additional information from one or more offsite locations, to increase the number of operations performed bydrill driver10, or to change tool performance for particular tasks. For example, where electronic clutch settings for multiple different fasteners are available for multiple different material combinations, the user can download additional data for these clutch settings which will automatically be saved for use for operation ofdrill driver10. To receive new data, areceiver264 provided indrill driver10 is connected to aprogrammable controller266. According to one aspect, anapplication library268 that is remote fromdrill driver10 contains data to transfer to drilldriver10. Data stored atapplication library268 can be transferred upon query by the user via awireless signal path270 to auser interface device272. Predetermined password or authorization codes can be sent to the user to authorize entry intoapplication library268.User interface device272 can be one of multiple devices, including computers or portable cell phones such as a smartphone. The data received wirelessly by theuser interface device272 and temporarily stored therein can be subsequently transferred by the user via awireless signal path274 to drilldriver10. The data received via thewireless signal path274 fromuser interface device272 is received atreceiver264 and stored byprogrammable controller266 or other memory devices/functions ofdrill driver10. This operation increases or supplements the database of data saved bydrill driver10 such that new information that may become available during the lifetime ofdrill driver10 can be used.
• Referring toFIG. 19, an initialization flow diagram276 identifies the various steps taken by the electronic control system ofdrill driver10 upon initial startup of the unit. In aninitialization step278, variables and hardware required during startup of the unit are initialized. In a followingread EEPROM step280, the data saved in the EEPROM ofmicrocontroller42 is read to determine the last mode of operation and thereby used to initialize the mode selection for initial operation ofdrill driver10. In acheck status step282, it is determined whether any of a power off timeout has occurred, whether an under-voltage cutoff has occurred, whether a high temperature cutoff has occurred, or if an over-current flag is indicated. If none of the conditions identified bycheck status step282 are present, a subsequentread trigger step284 is performed wherein the analog-digital converter (ADC) fortrigger28 is read to determine if the ADC signal is greater than a predetermined start limit. If the start limit is not exceeded, as determined in readtrigger step284, a stopmotor running operation286 is performed. If the limits read for the trigger ADC signal inread trigger step284 are greater than the predetermined start limits, aselect mode step288 operates to return to thecheck status step282.
• Following the stopmotor running operation286, a firstcheck button step290 is performed wherein it is determined if a forward operational selection button or switch is actuated. If the firstcheck button step290 is positive, a set forwardmode step292 is performed. If the firstcheck button step290 is negative, a secondcheck button step294 is performed, wherein it is determined if a reverse operational selection button or switch has been actuated. If the secondcheck button step294 is positive, a setreverse mode step296 is performed. If the secondcheck button step294 is negative, a thirdcheck button step298 is performed wherein a determination is made if the drive mode button or drive mode selector is actuated. If the thirdcheck button step298 is positive, a setdrive mode step300 is performed. If the thirdcheck button step298 is negative, a fourthcheck button step302 is performed wherein it is determined if the drill mode button or drill mode selector is actuated. If the result of the fourthcheck button step302 is positive, a setdrill mode step304 is performed. If the fourthcheck button step302 is negative, aclear flag step306 is performed wherein an auto seating flag is set to zero.
• Returning to thecheck status step282, if any of the items checked are indicated, astop motor step308 is performed to stop operation ofmotor34. Following thestop motor step308, a savedstep310 is performed wherein last data received, such as a maximum operating torque or operating current, is saved to the EEPROM ofmicrocontroller42. Following savedstep310, a power offstep312 is performed turning off operating power to drilldriver10 and entersleep mode step314 is performed following the power offstep312 to save electrical battery energy ofdrill driver10.
• Referring toFIG. 20 and again toFIGS. 1-2 and12, a diagram316 of the electronic control circuit of the present disclosure is provided. Thebattery16 voltage is normally isolated when atrigger switch318 is open. Whentrigger switch318 is closed, for example by depressingtrigger28, a DC/DC 10-volt supply320 is energized bybattery16. The DC/DC 10-volt supply320 is a 10-volt DC regulator that supplies power to theLED display screen100 and to an “H” bridge driver which will be further described herein. Also connected to DC/DC 10-volt supply320 is a 3-volt supply322. Three-volt supply322 provides 3-volt power for operation of electronics logic. TheLED display screen100, as previously described herein, provides multiple LEDs including first through sixth LEDs102-112. A modeselect module324 receives input from operation of eitherdrill selector switch170 ordriver selector switch172. TheLED display screen100, 3-volt supply322, modeselect module324, and rotary potentiometer/switch assembly32 are each connected to amicrocontroller42.Microcontroller42 controls all peripheral features and interfaces, sets the direction of operation and the pulse-width module setting for “H” bridge control, and further processes all analog input signals fordrill driver10. An “H”bridge driver328 is also connected tomicrocontroller42. “H”bridge driver328 is a motor controller for a four MOSFET (metal-oxide-silicon field-effect transistor) bridge and controls forward, reverse, and breaking functions ofmotor34. An “H”bridge330 is a group of four MOSFETs connected in an “H” configuration that drivemotor34 in both forward and reverse directions. Acurrent amplifier332 senses the current draw across a shunt resistor and amplifies the current signal for themicrocontroller42.
• Referring toFIG. 21, a motor control mode flow diagram334 identifies the various operational steps performed during motor control mode operation. A readtrigger position step336 is initially performed to identify an “on” or “off” position oftrigger28. Following the readtrigger position step336, atrigger release check338 is performed to identify whentrigger28 is released following depression. Iftrigger28 has been released, astop motor step340 is performed, stopping operation ofmotor34. Asubsequent return step342 is performed to return to the motor control mode. If thetrigger28 has not been released, as determined bytrigger release step338, a settingstep344 is performed wherein the pulse-width modulation is set and an FET (field effect transistor) drive is enabled. Following the settingstep344, acheck step346 is performed to determine if a battery under-voltage trip has occurred. If a battery under-voltage trip has occurred, thestop motor step340 is performed. If no battery under-voltage trip has occurred duringcheck step346, a subsequent battery over-temperature check348 is performed to determine if an over-temperature condition ofbattery pack16 has occurred. If a battery over-temperature condition has occurred, thestop motor step340 is performed. If there is no indication of a battery over-temperature condition, amonitoring step350 is performed wherein the motor back EMF (electromagnetic field) and load current are monitored during the time period of operation in motor control mode.
• Referring toFIG. 22A and again toFIGS. 1-6 and8, as the user rotatesrotary member36 to adjust or set a clutch torque setting, individual ones of the first through sixth LEDs102-112 may be illuminated. This provides visual indication to the user of the relative increase or decrease in torque setting. Initially, upon rotation in any direction ofrotary member36, in astep352 all of the green or blue LEDs that are currently illuminated are turned off. Following this, a read torqueselect input step354 is performed wherein the electrical signal generated by rotation ofrotary member36 is read which corresponds to a selected torque input.
• According to several aspects, axial rotation ofrotary member36 provides twelve individual torque settings. In a first torqueselect step356, a determination is made if the selected torque input corresponds to torque setting12. Ifstep356 is affirmative, in a settingtorque step358, a torque level of 20 amps is set. At this time, in astep360, green LED represented bysixth LED112 is illuminated. If the result ofstep356 is negative, in a followingstep362, a determination is made if the selected torque input corresponds to torque setting11. If affirmative, in astep364, a torque of 18.5 amp level is set. At this same time, the color ofsixth LED112 is changed from green to blue in astep366. If the response fromstep362 is negative in astep368, a determination is made if the selected torque input corresponds to torque setting10. If the answer is affirmative, in astep370, a torque level of 17 amps is set. At this time, thefifth LED110 is illuminated using a green color in astep372. If the response to step368 is negative, in astep374, a determination is made if the selected torque input corresponds totorque setting9. If the response is affirmative, in astep376, a torque of 15.5 amp level is set. At this time,fifth LED110 is changed from green to blue in astep378. If the response fromstep374 is negative, in astep380, a determination is made if the selected torque input corresponds totorque setting8. If affirmative, in astep382, a torque level of 14 amps is set. At this time, thefourth LED108 is illuminated using a green color in astep384. If the response fromstep380 is negative, in astep386, a determination is made if the selected torque input corresponds totorque setting7. If affirmative, in astep388, a torque of 12.5 amp level is set. At this time, thefourth LED108 is changed from green to a blue color in astep390. If the response to step386 is negative, in astep392, a determination is made if the selected torque input corresponds totorque setting6. If affirmative, in astep394, a torque of 11 amp level is set. At this time, thethird LED106 is illuminated using a green color in astep396. If the response fromstep392 is negative, in astep398, a determination is made if the selected torque input corresponds totorque setting5. If affirmative, in astep400, a torque of 9.5 amp level is set. At this time, thethird LED106 is changed from a green to a blue color in astep402. If the response to step398 is negative, in astep404, a determination is made if the selected torque input corresponds totorque setting4. If affirmative, in astep406, a torque of 8 amp level is set. At this time, thesecond LED104 is illuminated using a green color in astep408. If the response to step404 is negative, in astep410, a determination is made if the selected torque input corresponds totorque setting3. If affirmative, in astep412, a torque of 6.5 amp level is set. At this time, thesecond LED104 is changed from a green to a blue color in astep414. If the response to step410 is negative, in astep416, a determination is made if the selected torque input corresponds totorque setting2. If affirmative, in astep418, a torque of 5 amp level is set. At this time, thefirst LED102 is illuminated using a green color in astep420. If the response to step416 is negative, in astep422, a determination is made if the selected torque input corresponds totorque setting1. If affirmative, in astep424, a torque of 3.5 amp level is set. At this time, thefirst LED102 is changed in color from green to blue in astep426. It is noted that the sequencing identified in clutch torque flow diagram351 corresponds to a decreasing torque value manually set by the user. The sequence is reversed if the user is selecting torque values that increase in value.
• Referring toFIG. 22B, a lookup table428 provides saved values corresponding to the selected torque input level. A torque level in amps corresponding to the torque input level is also provided, as well as the corresponding color and illuminated LED for the LED display.
• Referring toFIG. 23 and again toFIGS. 1-6 and8, when the user manually displaces the rotary potentiometer/switch assembly32 by pushing in either a right-to-left or left-to-right direction againstrotary member36, adrill driver10 clutch rotation direction is selected or changed. As previously noted, opposite displacements of rotary potentiometer/switch assembly32 provide either a forward or a reverse clutch rotational direction. A forward/reverse LED display flow diagram430 identifies the corresponding LED display that is presented upon selecting either the forward direction in aforward step434 or the reverse direction in areverse step436. These steps follow an initial inquiry in a forward/reverse step432 initiated by motion of therotary member36. If the forward rotational direction is selected, following forward step434 and in sequential order, each of the first through sixth LEDs102-112 are illuminated. Initially, in astep438, thefirst LED102 is illuminated using a blue color. Following a 60millisecond delay step440,first LED102 is turned off andsecond LED104 is turned on in a blue color in astep442. Following a 60millisecond delay step444,second LED104 is turned off andthird LED106 is turned on in a blue color in astep446. Following another delay of 60 ms in astep448,third LED106 is turned off andfourth LED108 is turned on in a blue color in astep450. Following a delay of 60 ms in astep452,fourth LED108 is turned off andfifth LED110 is turned on in a blue color in astep454. Following an additional 60 ms delaystep456, thefifth LED110 is turned off and thesixth LED112 is turned on in a blue color in astep458. Following a final delay of 60 ms in astep460, thesixth LED112 is turned off in astep462. Based on the sequence of operation of first through sixth LEDs102-112 in the forward operating mode, the LEDs will appear to rapidly illuminate in a clockwise direction.
• An opposite operation starting with illumination ofsixth LED112 and continuing tofirst LED102 occurs if thereverse step436 is actuated. Followingreverse step436,sixth LED112 is illuminated in a blue color in astep464. Following a delay of 60 ms in astep466, thesixth LED112 is turned off and thefifth LED110 is turned on in a blue color in astep468. Following a delay of 60 ms in astep470, thefifth LED110 is turned off and thefourth LED108 is turned on in a blue color in astep472. Following a delay of 60 ms in astep474, thefourth LED108 is turned off and thethird LED106 is turned on in a blue color in astep476. Following an additional delay of 60 ms in astep478, thethird LED106 is turned off and thesecond LED104 is turned on in a blue color in astep480. Following a delay of 60 ms in astep482, thesecond LED104 is turned off and thefirst LED102 is turned on in a blue color in astep484. Finally, following a delay of 60 ms in astep486, thefirst LED102 is turned off in astep488. Based on the sequence of operation of sixth through first LEDs112-102 in the reverse operating mode, the LEDs will appear to rapidly illuminate in a counter-clockwise direction.
• One of the drawback of the LED-based display described above is that the clutch setting is not quantified for the tool operator. Analternative display600 for adrill driver10 having an electronic clutch is shown inFIG. 28. In this alternative embodiment, a number corresponding to the clutch setting is displayed on thedisplay600. For example, the numeric value may range from one to six as described above in relation toFIG. 10. In one embodiment, thedisplay600 may be implemented using a simple dot matrix display although other types of displays are also contemplated by this disclosure. The clutch setting can be set, for example, using therotary member36. Other types on mechanisms fall for selecting a clutch setting also within the broader aspects of this feature. In some embodiments, alight sensor602 may also be integrated into the housing of thedrill driver10. The signal from the light sensor is received by the controller and can be used to adjust the brightness of the display, thereby improving the visibility of the display in different light conditions.
• For drill drivers having multi-speed transmissions, the maximum clutch torque setting for the mechanical clutch is dictated by the maximum torque that can be achieved in a high speed (low torque) setting. Setting the maximum torque setting for the clutch in this manner prevents the tool from stalling regardless of the speed and clutch settings but creates a difference in the maximum torque setting between low speed and high speed modes. In an electronic clutch, different ranges of clutch settings can be assigned to each of the different speed settings. For example, in a high speed (low torque) setting, the clutch settings may range between eight settings (i.e., 1-8); whereas, in the low speed (high torque) setting, the clutch setting may range between twelve settings (i.e., 1-12), where for clutch setting correlates to a different user selectable predefined maximum torque level as noted above. To support this arrangement, the clutch settings are display by the controller on thedisplay600 using different scales. When the tool is in the low speed setting, all twelve clutch settings can be selected by the user and thus may be displayed on the display. When the tool is in the high speed setting, only the first eight settings (i.e., 1-8) are selected by the user and thus may be display on the display. In some embodiments, the clutch setting mechanism (e.g., rotary member36) enables the user to pick from the full range of settings (e.g., 12 different settings). In the case the tool is in the high speed setting, values for the first eight setting are displayed as well as the value for the eight setting being displayed for the four additional setting available on the clutch setting mechanism. That is, values for the twelve selectable setting of the rotary member are displayed as 1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 8, 8, respectively. While reference is made to a drill driver with two speed transmission, it is readily understood that this concept may be extended to three or more speed transmissions as well.
• Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
• The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
• The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims (20)

What is claimed is:

1. A method of controlling operation of a power tool having an electric motor drivably connected to an output spindle to impart rotary motion thereto, comprising:

receiving, by a controller residing in the power tool, an input indicative of a clutch setting for an electronic clutch, the clutch setting being selectable from a drill mode and a drive mode;

monitoring, by the controller, torque applied to the output spindle when the clutch setting is in a drive mode by

sampling periodically current delivered to the electric motor;

storing a sequence of current measures most recently sampled, the sequence of current measures being stored in a memory of the power tool; and

determining a slope for the sequence of current measures by way of linear regression;

interrupting, by the controller, transmission of torque to the output spindle based in part on the slope of the sequence of current measures and when the clutch setting is in a drive mode; and

disregarding, by the controller, torque applied to the output spindle when the clutch setting is in drill mode.

2. The method ofclaim 1 further comprises

detecting, by the controller, an occurrence of a trigger switch being released and subsequently depressed by the tool operator, where the trigger switch controls quantity of electric power delivered to the electric motor and the occurrence of the trigger switch being released and subsequently depressed by the tool operator occurs within a time limit of interrupting transmission of torque; and

energizing, by the controller, the electric motor for a period of time after generating haptic feedback and in response to detecting the occurrence of the trigger switch being released and subsequently depressed by the tool operator.

3. The method ofclaim 1 further comprises

comparing, by the controller, the slope to a minimum slope threshold;

incrementing, by the controller, a slope counter by one when the slope exceeds the minimum slope threshold;

evaluating, by the controller, the slope counter in relation to a setting criteria, where the setting criteria is indicative of a desired stopping position for a fastener being driven by the power tool; and

interrupting, by the controller, transmission of torque to the output spindle when the slope counter meets the setting criteria.

4. The method ofclaim 3 further comprises

storing, by the controller, a sequence of values for the slope counter; and

evaluating, by the controller, the sequence of values for the slope counter in relation to the setting criteria.

5. The method ofclaim 4 further comprises interrupting transmission of torque when values in the sequence of values for the slope counter are increasing from an oldest value to a most recent value.

6. The method ofclaim 4 further comprises interrupting transmission of torque when values in the sequence of values for the slope counter increase from an oldest value to an intermediate value and decrease from the intermediate value to a most recent value.

7. The method ofclaim 1 further comprises providing a visual indicator for the clutch setting during the operation of the tool.

8. The method ofclaim 1 wherein receiving an input further comprises receiving a signal from one or two buttons provided on a housing of the power tool, where one of the two buttons is associated with the drill mode and other of the two buttons is associated with the drive mode.

9. The method ofclaim 8 further comprises illuminating an icon integrated into one of the two buttons actuated by the tool operator, where the icon is indicative of the operating mode associated with the actuated button.

10. The method ofclaim 1 further comprising

determining, by the controller, a magnitude of current being delivered to the electric motor immediately prior to interrupting transmission of torque;

storing, by the controller, the magnitude of current in a storage device in response to an input from the tool operator;

interrupting transmission of torque to the output spindle during a subsequent operation of the tool when the amount of current being delivered to the electric motor is equal to or exceeds the stored magnitude of current.

11. A portable, hand held power tool, comprising:

a housing;

an electric motor drivable connected to an output spindle to impart rotary motion thereto;

a current sensor configured to sample current being delivered to the electric motor;

an input component operable by the tool operator to set a clutch setting for tool, the clutch setting being selectable from a drill mode, an automated drive mode and one or more user-defined drive modes, where each of the user-defined drive modes specifies a different value of torque at which to interrupt transmission of torque to the output spindle; and

a controller configured to receive the clutch setting from the input component and current measures from the current sensor, wherein the controller operates, when the clutch setting is an automated drive mode, to interrupt torque to the output spindle monitor rate of change of the current measures and interrupt torque to the output spindle in response to the rate of change of current measures exceeding a rate change threshold, the controller further operates, when the clutch setting is in a selected one of the user-defined drive modes, to set a value of a maximum current threshold in accordance with the selected one of the user-defined drive modes and interrupt torque to the output spindle in response to the current measures exceeding the maximum current threshold.

12. The power tool ofclaim 11 wherein the controller, when the clutch setting is an automated drive mode, operates to receive current measure from the current sensor, stores a sequence of current measures most recently sampled in a memory of the power tool, and determine a slope for the sequence of current measures by way of linear regression and operates to interrupt transmission of torque based in part on the slope of the sequence of current measures.

13. The power tool of claim ofclaim 12 wherein the controller further operates to compare the slope to a minimum slope threshold; adjust a slope counter in accordance with the comparison of the slope with the minimum slope threshold, evaluate the slope counter in relation to a setting criteria, and interrupt transmission of torque to the output spindle when the slope counter meets the setting criteria, where the setting criteria is indicative of a desired stopping position for a fastener being driven by the power tool.

14. The power tool ofclaim 10 wherein the controller, when the clutch setting is a drill mode, ignores torque applied to the output spindle.

15. The power tool ofclaim 10 wherein the controller provides haptic feedback to the tool operator concurrently with interrupting transmission of torque to the output spindle.

16. The power tool ofclaim 10 wherein the input component is further defined as two pushbuttons integrated into the housing, such that actuation of one pushbutton sets the clutch setting to a drill mode and actuation of the other pushbutton sets the clutch setting to a drive mode.

17. The power tool ofclaim 16 wherein one of the two pushbuttons actuated by the tool operator is illuminated during operation of the tool.

18. The power tool ofclaim 10 wherein the input component is further defined as a rotary potentiometer switch assembly including:

an assembly platform rotatably mounted to the body;

a rotary device rotatably mounted to the assembly platform such that manual axial rotation of the rotary device acts to create a clutch setting; and

opposed first and second directional switches mounted to the assembly platform, wherein when one of the first or second directional switches contacts the body during a manual rotation of the assembly platform, either a forward or a reverse operating direction of rotation command for the output spindle is created.

19. The power tool ofclaim 10 further comprising a display port located on the housing including multiple bi-color light emitting diodes (LEDs) each operating to display three colors, including two primary colors and a third color which is a mix of the two primary colors, each LED color providing visual indication of multiple different operating modes of the power tool.

20. The power tool ofclaim 10 further comprising a display port located on the housing, wherein a numeric value for the selected one of the user-defined drive modes is presented on the display port.

Images