US20170000305A1 - Vacuum cleaner with brushroll control - Google Patents

Abstract

A vacuum cleaner includes a base having a floor nozzle that defines a suction chamber, a brushroll driven by a brushroll motor, and a brushroll motor sensor configured to measure an electrical current used by the brushroll motor. The vacuum cleaner further includes a pressure sensor configured to measure an internal pressure within the vacuum cleaner, and a controller in communication with the brushroll motor sensor and the pressure sensor. The controller is operable to control an operating speed of the brushroll motor based on feedback received from the pressure sensor and the brushroll motor sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority to U.S. Provisional Patent Application No. 62/186,998, filed Jun. 30, 2015 and claims priority to U.S. Provisional Patent Application No. 62/187,001, filed Jun. 30, 2015, the entire contents all of which are hereby incorporated by reference herein.
BACKGROUND
• The present invention relates to vacuum cleaners, and more particularly to vacuum cleaners with a brushroll.
SUMMARY
• In one aspect, the invention provides a vacuum cleaner including a base having a floor nozzle that defines a suction chamber, a brushroll driven by a brushroll motor, and a brushroll motor sensor configured to measure an electrical current used by the brushroll motor. The vacuum cleaner further includes a pressure sensor configured to measure an internal pressure within the vacuum cleaner, and a controller in communication with the brushroll motor sensor and the pressure sensor. The controller is operable to control an operating speed of the brushroll motor based on feedback received from the pressure sensor and the brushroll motor sensor.
• In another aspect, the invention provides a method of controlling a brushroll motor in a vacuum cleaner. The method includes sensing a pressure within the vacuum cleaner, sensing a motor current of the brushroll motor used to drive the brushroll, comparing the sensed pressure with one or more reference pressure values, comparing the motor current with one or more reference current values, and controlling operation of the brushroll motor based on the sensed pressure and motor current. Controlling operation of the brushroll motor includes turning the brushroll motor on based on the sensed pressure.
• In another aspect, the invention provides a method of controlling a brushroll motor in a vacuum cleaner. The method includes sensing an electrical current used by the brushroll motor to drive the brushroll at a first speed, sensing the speed of the brushroll motor or the brushroll, varying the electrical current to maintain the first speed of the brushroll, and determining a change in current drawn by the brushroll motor to maintain the first speed of the brushroll. The method also includes comparing the change in current to a threshold current change value, maintaining the first brushroll speed when the change in current is less than the threshold current change value, and maintaining a second brushroll speed different than the first brushroll speed when the change in current is greater than the threshold current change value.
• Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a vacuum cleaner according to an embodiment of the invention.
• FIG. 2 is a perspective view of a base of the vacuum cleaner ofFIG. 1, with a portion removed.
• FIG. 3 is a bottom view of the base ofFIG. 2.
• FIG. 4 is a top view of the base ofFIG. 2, with a portion removed.
• FIG. 5 is a perspective view of the base ofFIG. 2, with a portion removed.
• FIG. 6 is a perspective view of a portion of a pressure sensor used in the base ofFIG. 2.
• FIG. 7 is a perspective view of a portion of the pressure sensor used in the base ofFIG. 2.
• FIG. 8 is a perspective view of a portion of the pressure sensor used in the base ofFIG. 2.
• FIG. 9 is a cross-sectional view of a portion of the base ofFIG. 2.
• FIG. 10 is a graph illustrating suction and brushroll motor data for a vacuum cleaner passing from carpet to hard floor.
• FIG. 11 is a block diagram illustrating the interaction between various sensors, a controller, and brushroll elements.
• FIG. 12 is a perspective view of a pressure sensor according to another embodiment.
• FIG. 13 is a cross-sectional view of the pressure sensor ofFIG. 12.
• FIG. 14 is an exploded view of a portion of the pressure sensor ofFIG. 12.
• FIG. 15 is a graph illustrating pressure and voltage correlation data for the pressure sensor ofFIG. 11 in a variety of operating conditions.
• Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
DETAILED DESCRIPTION
• FIG. 1 illustrates anexemplary vacuum cleaner10. The illustratedvacuum cleaner10 is an upright vacuum cleaner and includes abase assembly14 and ahandle assembly18 pivotally coupled to thebase assembly14. In other embodiments, other types and styles of vacuum cleaners can be utilized (e.g., canister, handheld, utility, etc.).
• In the illustrated embodiment of thevacuum cleaner10, thebase assembly14 is movable along a surface to be cleaned, such as a carpeted or hard-surface floor. Thehandle assembly18 extends from thebase assembly14 and allows a user to move and manipulate thebase assembly14 along the surface. Thehandle assembly18 is also movable relative to thebase assembly14 between an upright position (FIG. 1) and an inclined position (not shown).
• Thehandle assembly18 includes amaneuvering handle22 having agrip26 for a user to grasp and maneuver thevacuum cleaner10. In the illustrated embodiment, thevacuum cleaner10 also includes adetachable wand30. Thewand30 may be used to clean above-floor surfaces (e.g., stairs, drapes, corners, furniture, etc.). An accessory tool34 (e.g., a crevice tool, an upholstery tool, a pet tool, etc.) is detachably coupled to thehandle assembly18 for storage and may be used with thewand30 for specialized cleaning.
• With continued reference toFIG. 1, acanister38 is supported on thehandle assembly18 and includes aseparator42 and adirt cup46. Theseparator42 removes dirt particles from an airflow drawn into thevacuum cleaner10 which are then collected by thedirt cup46. Theseparator42 may be a cyclonic separator, filter bag, or other separator as desired. In the illustrated embodiment, thecanister38 including thedirt cup46 is removable from thehandle assembly18 to facilitate emptying the dirt particles from thedirt cup46.
• Thevacuum cleaner10 further includes a suction motor (not shown) contained within a motor housing54 (FIG. 1) and a suction source (not shown), such as an impeller fan assembly, driven by the suction motor. The suction motor selectively receives power from a power source (e.g., a cord for plugging into a source of utility power, a battery, etc.) to generate the suction airflow through thevacuum cleaner10.
• Now referring toFIGS. 2-4, thebase assembly14 includes a suction nozzle orfloor nozzle58 having a suction chamber70 (FIG. 3). In the illustrated embodiment, thesuction chamber70 is formed between anupper portion62 and alower portion66 of the floor nozzle58 (FIG. 2). Air and debris may be drawn into thesuction chamber70 through an elongate inlet opening74 in the lower portion66 (FIG. 3). In the illustrated embodiment, a plurality ofcross bars78 are positioned across the opening74 inhibiting ingress of electrical cords and other objects into theopening74. In other embodiments, thecross bars78 may be omitted. After entering thesuction chamber70, air and debris pass through anozzle outlet82 that fluidly communicates with theseparator42.
• Optionally, thebase assembly14 includes a pair ofrear wheels86 and a pair of forward supporting elements orwheels90 spaced from therear wheels86 and located generally adjacent theinlet opening74. Thewheels86,90 facilitate movement of thebase assembly14 along the surface to be cleaned. In addition, theforward wheels90 may assist in positioning theinlet74 of thefloor nozzle58 at a desired height above the surface to be cleaned.
• With reference toFIG. 3, an agitator orbrushroll94 is rotatably supported at its ends within thenozzle suction chamber70. Thebrushroll94 includes an array ofbristle tufts98 or other protrusions that may extend through theopening74 to agitate the surface to be cleaned. Theagitator94 is rotatably driven by a drive belt106 (FIG. 4) that receives power from abrushroll motor108. In the illustrated embodiment, thebrushroll motor108 drives thebrushroll94, while the suction motor drives the suction source. In other embodiments, a single motor may be provided to drive the suction source and thebrushroll94.
• With reference toFIG. 4, thefloor nozzle58 also includes apressure sensor110. The illustratedpressure sensor110 is in communication with the suction chamber70 (FIG. 3) for determining a nozzle suction pressure within thefloor nozzle58. Alternatively, thepressure sensor110 can be used to determine a nozzle suction pressure in any other type of nozzle, such as an accessory wand or other above-floor cleaning attachment. The illustratedpressure sensor110 is disposed proximate thesuction chamber70; however, in other embodiments, thepressure sensor110 can be located remote from thesuction chamber70. In such embodiments, thepressure sensor110 can monitor the nozzle suction pressure via a tube or other suitable means having an end exposed to thesuction chamber70.
• The illustratedpressure sensor110 includes a pressure sensor housing114 (FIG. 5) defining a chamber that is at least partially enclosed by a pressuresensor cap portion118. Theupper portion62 of thefloor nozzle58 includes an aperture between thepressure sensor housing114 and thesuction chamber70 forming a pressure sensor inlet122 (FIGS. 8 and 9) to allow for fluid communication between thepressure sensor110 and thesuction chamber70. With reference toFIG. 5, the housing includes aninternal wall126 dividing the inner chamber of thepressure sensor110 such that theinlet122 is at least partially isolated from the remainder of thepressure sensor110. Theinternal wall126 includes an aperture that allows for fluid communication between theinlet122 and the remainder of thepressure sensor110 while providing a barrier to inhibit the intake of dust particles and debris flowing through thesuction chamber70. In the illustrated embodiment, the aperture is a U-shaped opening in theinternal wall126.
• Referring toFIGS. 8 and 9, thepressure sensor110 also includes aninlet guard130 positioned adjacent to theinlet122 to further limit the intake of dust particles and debris into thepressure sensor110. Theinlet guard130 may attach to theinlet122. Further, theinlet guard130 may be shaped in various ways to provide desirable flow characteristics within thesuction chamber70 and/or the chamber of thepressure sensor110. For example, the illustratedinlet guard130 provides asloped surface134 such that the area of theinlet122 decreases in a direction toward the interior of thepressure sensor110, allowing fewer particles to enter the pressure sensor chamber.
• Thepressure sensor housing114 may be integrally formed in thefloor nozzle58. Thepressure sensor housing114 may be integrally formed in theupper portion62. Alternatively, thepressure sensor housing114 may be a separate component assembled to thevacuum cleaner10. Alternatively or additionally, theair inlet122 of thepressure sensor110 may be configured as a fitting, optionally with a barb feature at an end of the fitting, or a threaded fitting, or compression fitting, or other fitting, to be in fluid communication with thesuction chamber70 using a duct or a tube connected to the fitting.
• With reference toFIGS. 6 and 7, the illustratedpressure sensor110 also includes apiston block138 holding amagnet142 that is movable with respect to a hall-effect sensor150. In the illustrated embodiment, the hall-effect sensor150 is mounted to acircuit board146. Thepiston block138 is forced toward the hall-effect sensor150 by a spring (not shown), which may be positioned between theinternal wall126 and thepiston block138, while negative pressure within thesuction chamber70 generated by the suction source pulls on thepiston block138, tending to overcome the force of the spring and move thepiston block138 andmagnet142 away from thesensor150. Therefore, the relative distance of the piston block138 from the hall-effect sensor150 can be correlated to the suction pressure within thechamber70. Specifically, the higher the suction (i.e., the lower the pressure) within thesuction chamber70, the further thepiston block138 moves away from thesensor150 against the force of the spring, and vice versa. The hall-effect sensor150 andmagnet142 are used to determine the relative distance between thepiston block138 and thesensor150 to compute a sensed pressure. It should be understood that in other embodiments, other types of pressure sensors may be used, such as optical, piezoresistive, and the like.
• With reference toFIG. 11, thevacuum cleaner10 further includes abrushroll motor sensor133 and acontroller116 in communication with thesensors110,133. Thebrushroll motor sensor133 can be configured to sense a torque output or current draw of thebrushroll motor108. Thecontroller116 can receive and analyze data from thepressure sensor110 and thebrushroll motor sensor133 and use some or all of that data as feedback to control the rotational speed of thebrushroll motor108.
• In general operation, the suction motor drives the fan assembly or suction source to generate airflow through thevacuum cleaner10. The airflow enters thefloor nozzle58 through theinlet opening74 and flows into the suction chamber70 (FIG. 3). The airflow and any debris entrained therein then travel through thenozzle outlet82 and into theseparator42. After theseparator42 filters or otherwise cleans the airflow, the cleaned airflow is directed out of thecanister38 and into themotor housing54, (e.g., through an airflow channel extending through the handle assembly18) (FIG. 1). The cleaned airflow is ultimately exhausted back into the environment through air outlet openings.
• With reference toFIG. 11, during operation, thecontroller116 receives the data from thesensors110,133 and compares the sensed pressure from thepressure sensor110 and the sensed current and/or torque values from thebrushroll motor sensor133 with one or more corresponding predetermined thresholds. The predetermined thresholds (i.e., pressure, torque, and/or current) are associated with different floor types to represent a distinction between floor surfaces (e.g., carpet and hard floor). Thecontroller116 determines the floor surface by comparing the sensed pressure and the sensed motor current and/or torque values with the predetermined thresholds, and automatically operates thebrushroll motor108, and optionally the suction motor, in a manner optimized for the type of floor surface. For example, high-pile carpet will generally cause high suction (i.e., low pressure) within thesuction chamber70 and force thebrushroll motor108 to work harder (i.e., generate higher torque and draw more current), while a hard floor surface will lead to lower suction (i.e., higher pressure that is closer to atmospheric pressure) within thesuction chamber70 and will allow thebrushroll motor108 to work more easily (i.e., generate lower torque and draw less current).
• FIG. 10 illustrates exemplary suction and brushroll motor data for a vacuum cleaner passing from carpet to hard floor. Depending on the comparison of the sensed pressure, torque, and/or current with their corresponding threshold values, thecontroller116 operates thebrushroll motor108 in a desired state to drive thebrushroll motor108 at a desired speed. For example, thecontroller116 may operate thebrushroll motor108 at a slow rotational speed when thefloor nozzle58 is located on a hard floor surface to reduce scattering of debris and reduce energy consumed by thebrushroll motor108. Further, thecontroller116 may operate thebrushroll motor108 at a high rotational speed while thefloor nozzle58 is on carpet to better agitate dust particles out of the carpet fibers. Alternatively, thecontroller116 may shut off thebrushroll motor108 when thefloor nozzle58 is located on certain surfaces (e.g., hard floor), to conserve energy, reduce scattering of debris, and/or reduce wear on delicate surfaces.
• Thecontroller116 may also or alternatively operate the suction motor based on floor type. For example, thecontroller116 may operate the suction motor at a lower power on a hard floor surface to conserve energy or a higher power on a hard floor surface to increase debris pick-up. In some embodiments, the suction motor may be operated at a lower power on certain height carpets to reduce the clamp-down of thenozzle58 to the carpet so that thevacuum cleaner10 is easier to push.
• By continuously or intermittently monitoring pressure and motor current and/or torque using data from thesensors110,133, thecontroller116 determines when thevacuum10 passes from one surface type to another surface type and alters the brushroll speed, and optionally suction, to provide a pre-programmed vacuum cleaner operation in response to the different conditions created by different floor types. Either or both of thepressure sensor110 and thebrushroll motor sensor133 may be continually used to alter the rotational speed of thebrushroll motor108 in response to the sensed data. If thebrushroll motor108 is off, however, only thepressure sensor110 is used to determine a change in floor type.
• Referring toFIG. 11, aswitch112 may be provided to allow a user to selectively switch between different modes of operation, such as to put thevacuum cleaner10 in a “speed control mode.” in which thecontroller116 changes the rotational speed of the brushroll motor108 (and the brushroll94) in response to the sensed data, or in an “on/off mode”, in whichcontroller116 turns thebrushroll motor108 on or off in response to the sensed data. Such a switch may be positioned for easy access by a user for changing the operational mode of thevacuum cleaner10. In certain applications, either the speed control mode or the on/off mode may be preferred by the manufacturer, and theswitch112 may be positioned in a less accessible location to a user, such as behind a cover so that theswitch112 may be accessible to a user only if the cover or other portion of thefloor nozzle58 is removed. In some embodiments, theswitch112 is provided on thecircuit board146.
• While thevacuum cleaner10 is operated in the “speed control mode,” thepressure sensor110 and thebrushroll motor sensor133 continuously or intermittently provide sensed data representative of the suction pressure and the motor current and/or torque, as described above. When the sensed data of thepressure sensor110 and thebrushroll motor sensor133 correspond to the values associated with thevacuum cleaner10 operating on a carpet surface, or the like, thecontroller116 operates thebrushroll motor108 at a first rotational speed, for example, between about 1000 and 5000 revolutions per minute (RPM), or between about 2000 and 4000 RPM. When the sensed data of thepressure sensor110 and thebrushroll motor sensor133 correspond to the values associated with thevacuum cleaner10 operating on a hard floor surface, or the like, thecontroller116 operates thebrushroll motor108 at a second rotational speed that is lower than the first rotational speed, for example, between about 100 and 1000 RPM, or between about 300 and 600 RPM. Either or both of thepressure sensor110 and thebrushroll motor sensor133 may be continually or intermittently used to alter the rotational speed of thebrushroll motor108 in response to the sensed data. In alternative embodiments, either thepressure sensor110 or thebrushroll motor sensor133 may be omitted so that only the other of thepressure sensor110 or thebrushroll motor sensor133 provides feedback used to alter the rotational speed of thebrushroll motor108.
• While thevacuum cleaner10 is in the “on/off mode,” thepressure sensor110 continually monitors the nozzle suction pressure; however, thebrushroll motor sensor133 may monitor the motor current and/or torque when thebrushroll motor108 is on. When thebrushroll motor108 is off, the motor current and/or torque will not provide data useful in determining the type of floor surface thefloor nozzle58 is on. When the sensed data of thepressure sensor110 and thebrushroll motor sensor133 correspond to the values associated with thevacuum cleaner10 operating on a carpet surface, thecontroller116 operates the brushroll motor108 (and the brushroll94) at a first rotational speed. When the sensed data of thepressure sensor110 and thebrushroll motor sensor133 correspond to the values associated with thevacuum cleaner10 operating on a hard floor surface, or the like, thecontroller116 turns thebrushroll motor108 off. While thefloor nozzle58 is operating on the hard floor surface and thebrushroll motor108 is off, thecontroller116 relies on thepressure sensor110 alone to determine whether to turn thebrushroll motor108 on. Thecontroller116 may use either or both of thesensors110,133, to determine whether to turn thebrushroll motor108 off.
• In some embodiments, thevacuum cleaner10 further includes atachometer155 that measures a rotational speed of thebrushroll motor108 or thebrushroll94 during operation (FIG. 11). Thetachometer155 can include one or more hall-effect sensors, optical encoders, or any other type of sensor suitable for measuring rotational speed.
• The sensed brushroll speed data from thetachometer155 can be used by thecontroller116 in conjunction with data from thebrushroll motor sensor133 to maintain a relatively constant rotational speed of thebrushroll94. For example, when thebrushroll94 encounters increased resistance, such as when transitioning from a hard floor surface to a carpeted floor surface, thecontroller116 may increase the current supplied to thebrushroll motor108 to increase the torque output by thebrushroll motor108. When the brushroll94 encounters decreased resistance, such as when transitioning from a carpeted floor surface to a hard floor surface, thecontroller116 may decrease the current supplied to thebrushroll motor108 to decrease the torque output by thebrushroll motor108. In such embodiments, thecontroller116 compares the amount of current increase or decrease needed to maintain the speed of thebrushroll94 and compares the amount to a threshold current change value. If the current increase or decrease exceeds the threshold current value, then thecontroller116 operates thebrushroll94 at a second speed instead of the first speed.
• As thevacuum cleaner10 passes from one surface type to another, thecontroller116 uses the amount of current change needed to maintain a constant brushroll speed, as well as whether the current change is an increase or decrease to determine the kind of floor type thevacuum cleaner10 is operating on, and thecontroller116 adjusts the current supplied to thebrushroll motor108 to maintain the speed of thebrushroll94 at a speed desired for the particular floor type. In this way, thecontroller116 determines the type of floor surface using the change in brushroll motor current needed to maintain a speed compared to predetermined thresholds and automatically operates thebrushroll motor108, and optionally the suction motor, in a manner corresponding to the type of floor surface. In some cases, thecontroller116 may turn off thebrushroll motor108 if the current exceeds the threshold current value. Thecontroller116 may include overload protection programming.
• FIGS. 12-14 illustrate apressure sensor110′ according to another embodiment that can be used in conjunction with the vacuum cleaner10 (e.g., instead of thepressure sensor110 or in addition to the pressure sensor110).
• Thepressure sensor110′ includes abase portion120′ and acap portion118′ that cooperate to define apressure sensor housing114′. In some embodiments, thebase portion120′ is integrally formed with a wall bounding the airflow path of thevacuum cleaner10. Thehousing114′ contains adiaphragm123′ holding amagnet142′ that is movable with respect to thehousing114′ when thediaphragm123′ flexes (FIG. 13). Thediaphragm123′ is sandwiched between thebase portion120′ and thecap portion118′ such that thediaphragm123′ creates a substantially airtight seal between thebase portion120′ and thecap portion118′. Accordingly, thediaphragm123′ is subject to pressure forces resulting from any pressure imbalance between air contained within thebase portion120′ and air contained within thecap portion118′.
• The air inlet of thepressure sensor110′ is configured as a fitting125′, such as a hose barb or nipple, a threaded fitting, compression fitting, or other fitting. In the illustrated embodiment, the fitting125′ extends from thebase portion120′. The fitting125′ can be integrally formed with thebase portion120′ as a single piece, or alternatively, the fitting125′ can be formed separately and attached to thebase portion120′ by threads or another type of suitable airtight connection. The fitting125′ (i.e. the air inlet for thepressure sensor110′) is in fluid communication with thesuction chamber70 such that the pressure at the sensor air inlet is representative of the pressure within thesuction chamber70. In some embodiments, the fitting125′ receives one end of a tube (not shown) that extends to the suction chamber70 (e.g., to the pressure sensor inlet122 (FIGS. 8 and 9) on theupper portion62 of the floor nozzle58) to allow for fluid communication between thepressure sensor110′ and thesuction chamber70. In other embodiments, thepressure sensor110′ can be directly connected to thesuction chamber70.
• In the illustrated embodiment, a hall-effect sensor150′ is located on thecap portion118′ (FIG. 13). The hall-effect sensor150′ may be incorporated onto acircuit board146′. Alternatively, all or a portion of the hall-effect sensor may be positioned on or adjacent thecap portion118′ and electrically connected to a circuit board positioned in a separate location. Thecap portion118′ may include attachments for securing thecircuit board146′ or the hall-effect sensor150′ to thecap portion118′. In other embodiments, the hall-effect sensor150′ can be located on thebase portion120′. Negative pressure within thesuction chamber70 generated by the suction source pulls on thediaphragm123′, causing it to deform and movemagnet142′ away from thecircuit board146′ and the hall-effect sensor150′. Therefore, the relative distance ofmagnet142′ from the hall-effect sensor150′ is correlated to the suction pressure within thechamber70. Specifically, the higher the suction (i.e., the lower the pressure) within thesuction chamber70, the further themagnet142′ moves away from the hall-effect sensor150′, and vice versa. Accordingly, the hall-effect sensor150′ is used to determine a sensed pressure.
• In some embodiments, thediaphragm123′ is afirst diaphragm123′ that is interchangeable with a second diaphragm (not shown) having different deflection characteristics under pressure. In such embodiments, the first and second diaphragms can be interchanged in order to vary the responsiveness or operating pressure range of thepressure sensor110′. In one embodiment, thefirst diaphragm123′ has a first attribute selected from a group consisting of thickness, durometer, shape, and material, and where the first diaphragm is replaceable with a second diaphragm having a second attribute selected from a group consisting of thickness, durometer, shape, and material. For example, thefirst diaphragm123′ may be made from a polyurethane material and the second diaphragm may be made from butyl rubber providing different response characteristics. In another example, thefirst diaphragm123′ may have a flat shape or uniform thickness and the second diaphragm may have a concave shape that is thicker near its perimeter, or alternatively thinner near its perimeter, providing different response characteristics, or in yet another alternative, the second diaphragm may have a shape having ribs, apertures, protrusions, grooves, or other shapes. In another example, thefirst diaphragm123′ may have a durometer of 25 Shore A and the second diaphragm may have a durometer of 40 Shore A, providing different response characteristics. In another example, the second diaphragm may be thinner than thefirst diaphragm123′ and therefore experience greater deflection than thefirst diaphragm123′ at a particular pressure difference between thebase portion120′ and thecap portion118′.
• For particular embodiments, thediaphragm123′ may be made from materials such as butyl rubber, polyurethane, silicone rubber, and other synthetic rubbers, thermoplastic elastomer (TPE), rubber, thermoplastic vulcanizates (TPV), thermoplastics, and other materials to provide response characteristics under pressure as desired for the application. Thediaphragm123′ may have a durometer between about 15 and 80 Shore A, or for particular embodiments between about 20 and 40 Shore A, or other hardnesses as desired to provide response characteristics under pressure as desired for the application. In one embodiment, thediaphragm123′ is a thermoplastic elastomer having a durometer between 20 and 30 Shore A.
• It was found that thepressure sensor110,110′ positioned in the air flow path of thevacuum cleaner10 can be used indicate more than one system condition, as shown inFIG. 15. For example, if the user does not install a filter (e.g., a pre-motor filter or a post-motor filter in some embodiments), the pressure reading at thesensor110,110′ will be higher than if the filter were installed. When the pressure exceeds a predetermined threshold, thecontroller116 may illuminate a signal to the user indicating that the filter is missing, and/or may turn off the suction motor to prevent damage to thevacuum cleaner10.
• Another common condition occurs when thedirt cup46 is filled with debris and needs to be emptied. The pressure reading at thesensor110,110′ decreases as thedirt cup46 fills, and when the pressure reaches a predetermined value, thecontroller116 may illuminate a signal to the user indicating that thedirt cup46 is full, and/or may turn off the suction motor. When thesensor110,110′ indicates a normal operating pressure, thecontroller116 may provide a signal, such as a light or other display, to the user to indicate that thevacuum10 is operating normally.
• In certain conditions, thevacuum cleaner10 may pick up a large object or enough debris to form a blockage in the air path, or a filter or filter bag in the vacuum may become clogged (i.e. may contain enough debris that vacuum cleaner performance is reduced). When a clog occurs, the system pressure, as measured by thesensor110,110′, drops. When the pressure drops to a predetermined level, thecontroller116 may provide a signal such as a light or other display to the user indicating that a clog has developed, and/or may turn off the suction motor.
• Accordingly, onepressure sensor110,110′ may be positioned in fluid communication with the air path of thevacuum cleaner10 to provide system information for a variety of operating conditions. In one embodiment, onepressure sensor110,110′ may be positioned in fluid communication with the air path of thevacuum cleaner10 to provide two or more indications of system performance selected from a group consisting of system clogged, filter bag full, dirt bin full, no filter present, no filter bag present, dirt bin empty, filter bag empty, and normal operation. Alternatively, onepressure sensor110,110′ may be positioned in fluid communication with the air path of thevacuum cleaner10 to provide three or more indications of system performance selected from a group consisting of system clogged, filter bag full, dirt bin full, no filter present, no filter bag present, dirt bin empty, filter bag empty, and normal operation. In yet another alternative, onepressure sensor110,110′ may be positioned in fluid communication with the air path of thevacuum cleaner10 to provide four or more indications of system performance selected from a group consisting of system clogged, filter bag full, dirt bin full, no filter present, no filter bag present, dirt bin empty, filter bag empty, and normal operation. In such embodiments, thecontroller116 continuously or periodically monitors the pressure sensor and provides a signal such as a light or other display to the user indicating a system condition, and/or may turn off the suction motor.
• Various features and advantages of the invention are set forth in the following claims.

Claims (21)

1. A vacuum cleaner comprising:

a base including a floor nozzle, the floor nozzle defining a suction chamber;

a brushroll driven by a brushroll motor;

a brushroll motor sensor configured to measure an electrical current used by the brushroll motor;

a pressure sensor configured to measure an internal pressure within the vacuum cleaner; and

a controller in communication with the brushroll motor sensor and the pressure sensor,

wherein the controller is operable to control an operating speed of the brushroll motor based on feedback received from the pressure sensor and the brushroll motor sensor.

2. The vacuum cleaner ofclaim 1, further comprising a dirt cup, wherein the controller is operable to determine a fullness level of the dirt cup based on feedback received from the pressure sensor.

3. The vacuum cleaner ofclaim 1, further comprising a filter, wherein the controller is operable to determine if the filter is present based on feedback received from the pressure sensor.

4. The vacuum cleaner ofclaim 1, further comprising a filter, wherein the controller is operable to determine if the filter is clogged based on feedback received from the pressure sensor.

5. The vacuum cleaner ofclaim 1, further comprising a filter housing and a filter received within the filter housing, wherein the pressure sensor is located within the filter housing.

6. The vacuum cleaner ofclaim 1, wherein the pressure sensor is located within the floor nozzle.

7. The vacuum cleaner ofclaim 1, wherein the pressure sensor includes

a housing defining a chamber,

a hall-effect sensor, and

a magnet moveable within the chamber relative to the hall-effect sensor in response to changes in the internal pressure.

8. The vacuum cleaner ofclaim 1, wherein the pressure sensor includes

a housing including a cap portion connected to a base portion,

a diaphragm supporting a magnet in the housing, the diaphragm and base portion defining a chamber arranged in fluid communication with an airflow path of the vacuum cleaner, the diaphragm moveable within the chamber in response to changes in the internal pressure of the vacuum cleaner, and

a hall-effect sensor configured to measure a relative distance between the magnet and the hall-effect sensor.

9. The vacuum cleaner ofclaim 8, wherein the diaphragm is sandwiched between the cap portion and the base portion.

10. The vacuum cleaner ofclaim 1, wherein at least a portion of the pressure sensor is formed integrally with the base or the handle of the vacuum cleaner.

11. The vacuum cleaner ofclaim 1, wherein the pressure sensor is positioned in fluid communication with an air path of the vacuum cleaner to provide two or more indications of system performance selected from a group consisting of system clogged, filter bag full, dirt bin full, no filter present, no filter bag present, dirt bin empty, filter bag empty, and normal operation.

12. The vacuum cleaner ofclaim 1, further comprising a tachometer configured to measure a speed of the brushroll motor or the brushroll to help maintain the speed of the brushroll motor or brushroll, the speed based on the sensed motor current and the sensed pressure.

13. A method of controlling a brushroll motor in a vacuum cleaner, the method comprising:

sensing a pressure within the vacuum cleaner;

sensing a motor current of the brushroll motor used to drive a brushroll;

comparing the sensed pressure with one or more reference pressure values;

comparing the sensed motor current with one or more reference current values; and

controlling operation of the brushroll motor based on the sensed pressure and the sensed motor current,

wherein controlling operation of the brushroll motor includes turning the brushroll motor on based on the sensed pressure.

14. The method ofclaim 13, wherein controlling operation of the brushroll motor further includes altering an operating speed of the brushroll motor based on at least one of the sensed pressure or sensed motor current.

15. The method ofclaim 13, wherein controlling operation of the brushroll motor further includes turning the brushroll motor off based on at least one of the sensed pressure or the sensed motor current.

16. The method ofclaim 15, wherein turning the brushroll motor off is based on the sensed pressure.

17. The method ofclaim 15, wherein turning the brushroll motor off is based on the sensed motor current.

18. The method ofclaim 15, wherein turning the brushroll motor off is based on both the sensed pressure and the sensed motor current.

19. The method ofclaim 13, further comprising

providing a first mode in which controlling operation of the brushroll motor further includes altering an operating speed of the brushroll motor based on at least one of the sensed pressure or the sensed motor current;

providing a second mode in which controlling operation of the brushroll motor further includes turning the brushroll motor off based on at least one of the sensed pressure or the sensed motor current; and

providing a switch to selectively choose the first mode or the second mode.

20. The method ofclaim 13, further comprising measuring an operating speed of the brushroll motor or the brushroll to help maintain the operating speed of the brushroll motor or brushroll, the speed of the brushroll motor or brushroll being based on the sensed motor current or the sensed pressure.

21-43. (canceled)

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