US20050102866A1 - Multi-function work machine - Google Patents

Abstract

A work machine having a first work member and a second work member, both operated from a pivotal control station. In a preferred embodiment the work machine has a backhoe assembly and a loader assembly both supported on a frame and operable from the pivotal control station. The work machine may have left and right low-profile drive systems that allow the first work member to perform work outside and parallel to the longitudinal center axis of the work machine. The work machine has a low-profile power source and operator platform that allow unobstructed visibility of the first and second work members from the control station.

Description

CROSS REFERENCE TO RELATED APPLICATION
• This application claims the benefit of U.S. Provisional Application No. 60/508,339 filed Oct. 3, 2003, the contents of which are incorporated fully herein by reference.
FIELD OF THE INVENTION
• The present invention relates generally to multi-function work machines, and in particular to a compact multi-function work machine adapted to accept alternative work tools.
SUMMARY OF THE INVENTION
• The present invention is directed to work machine comprising a frame, a first work member, a second work member, and a pivotal control station. The frame has a first end and a second end. The first work member is supported by the frame so that the first work member is operable at the first end of the frame. The second work member is supported by the frame so that the second work member is operable at the second end of the frame. The pivotal control station is supported by the frame and movable between at least a first position and a second position. The pivotal work station is adapted to control the first work member when in the first position and to control the second work member when in the second position.
• The present invention further comprises an excavator. The excavator comprises a frame having a first end and a second end, a control station, a low-profile power source supported by the frame, and a control station also supported by the frame. A first work member is supported by the frame so that the first work member is operable at the first end of the frame and operated by the control station. A second work member is supported by the frame so that the second work member is operable at the second end of the frame and operated by the control station. The second work member comprises a lift arm and a work tool. The lift arm has a first end and a second end. The first end of the lift arm is pivotally connected to the frame. The second end of the lift arm is movable in a range of motion comprising a lower position and an upper position. The work tool is supported by the second end of the lift arm. The excavator further comprises a first unobstructed line of sight and a second unobstructed line of sight. The first unobstructed line of sight extends from the control station over the low-profile power source to the work tool when the second end of the lift arm is in the lower position. The second unobstructed line of sight extends from the control station to beyond the work tool when the second end of the lift arm is in the upper position.
• The present invention further includes an excavator that comprises a frame, a low-profile left drive system and a low-profile right drive system. The low-profile left drive system and the low-profile right drive system are both supported by the frame and used to propel the frame in a plurality of directions. The excavator further comprises a first work member and a second work member. The first work member is supported by the frame so that the first work member is operable at the first end of the frame. The first work member comprises a swing arm, a swing post, a swing post actuator, and a swing arm actuator. The swing arm is pivotally connected to the frame and has a central longitudinal axis. The swing post is pivotally connected to the swing arm. The swing arm actuator is fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions. The plurality positions includes at least one position placing the swing post beyond the left drive system and at least one position placing the swing post beyond the right drive system. The swing post actuator is fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm. The second work member is supported by the frame so that the second work member is operable at the second end of the frame.
• Further still, the present invention includes a work machine comprising a frame, a pivotal control station, a pivotal first work member and a pivotal second work member. The frame has a first end, a second end and a longitudinal axis comprising a midpoint. The pivotal control station is supported by the frame and has a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis. The pivotal first work member is supported by the frame and has a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis of the frame. The pivotal second work member is supported by the frame and has a substantially horizontal pivot axis.
• The present invention further includes an excavator comprising a frame having a first end and a second end, a pivotal control station supported by the frame, a first work member, and a second work member. The first work member is supported by the frame so that the first work member is operable at the first end of the frame. The first work member comprises a swing arm pivotally connected to the frame, a swing post pivotally connected to the swing arm, and a work tool supported by the swing post. The second work member is supported by the frame so that the second work member is operable at the second end of the frame. The excavator further includes an unobstructed line of sight extending from the control station to the work tool of the first work member.
• Further still, the present invention includes, a work machine comprising a frame having a first end and a second end, a pivotal control station, a pivotal first work member, and a pivotal second work member. The control station is supported by the frame and has a substantially vertical pivot axis. The pivotal first work member is supported by the frame so that the first work member is operable at the first end of the frame. Further, the first work member comprises a substantially vertical pivot axis. The pivotal second work member is supported by the frame so that the second work member is operable at the second end of the frame and comprises a substantially horizontal pivot axis. The pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to the frame to create a close-coupled work machine.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a side elevational view of a multi-function work machine. The work machine has a first work member and a second work member both shown supported on a frame. The machine ofFIG. 1 is equipped with a pivotal control station from which the first and second work members may be operated.
• FIG. 2 is a perspective view of the frame of the work machine shown inFIG. 1.FIG. 2 illustrates positioning of the pivotal axes of the work members and the control station.
• FIG. 3 is a perspective cut-away view of the frame ofFIG. 2.FIG. 3 shows the attachment of the first work member to the frame. The first work member shown inFIG. 3 has a swing arm and a swing post used to support and move a work tool attached to the swing post.
• FIG. 4 is a top view of the work machine ofFIG. 1 illustrating alternate stowing positions of the excavator bucket.
• FIG. 5 is a top view of the work machine ofFIG. 4 having the roll-over protection canopy removed so that the operator's seat is visible.FIG. 5 illustrates the range of motion of the swing arm shown inFIG. 3.
• FIG. 6 is a top view of the work machine ofFIG. 5 illustrating the range of motion of the work tool when used with the swing arm and swing post of the present invention.
• FIG. 7 is a top view of the work machine illustrating the use of the excavator bucket to dig a trench.
• FIG. 8 is a side view of the work machine ofFIG. 1 illustrating an unobstructed line of sight from the control station to the work tool.
• FIG. 9 is a side view of the work machine ofFIG. 1 illustrating an unobstructed line-of-sight from the control station to an excavator bucket positioned below ground.
• FIG. 10 is a side view of the work machine illustrating a trencher as a work tool supported by the frame.
• FIG. 11 is a side view of the work machine of the present invention having an offsetable vibratory plow as an alternate work tool supported by the frame.
• FIG. 12 is a side view of the work machine having an alternative configuration. The work machine ofFIG. 12 has a “dump bed” attached to the work member.
DESCRIPTION
• Turning now to the figures and first toFIG. 1, there is shown therein awork machine10 of the present invention. Thework machine10 shown inFIG. 1 is an excavator that, among other things, may be used to dig trenches and move earth. Thework machine10 comprises aframe12 having afirst end14 and asecond end16. Theframe12 supports afirst work member18 and asecond work member20. Thefirst work member18 is supported by theframe12 so that it is operable at thefirst end14 of the frame. Thesecond work member20 is supported by theframe12 so that it is operable at thesecond end16 of the frame. Thework machine10 ofFIG. 1 further includes acontrol station22 supported by theframe12. Thecontrol station22 is movable between a first position A and a second position B. When placed in position B thecontrol station22 controls the function of thefirst work member18. Thesecond work member20 is controlled by thecontrol station22 when the control station is in position A.
• Thefirst work member18 may comprise atool carrier24. Thetool carrier24 may comprise aswing arm26 connected to theframe12, aswing post28 connected to the swing arm, and a work tool connected to the swing post. For purposes of illustration, the work tool ofFIG. 1 is a backhoe attachment used to dig trenches. The backhoe comprises aboom30, adipper32, and anexcavator bucket34. Theboom30,dipper32 andbucket34 are pivotally connected in series and positioned or moved with respect to each other usinghydraulic cylinders36,38, and40. The backhoe attachment is moved and positioned relative to theframe12 by moving theswing arm26 andswing post28. Theswing arm26 may have aswing arm actuator42 comprising a hydraulic cylinder that is adapted to pivot the swing arm and theswing post28 relative to theframe12 to a plurality of positions. A swing post actuator44 (FIG. 3) may be fixed to theswing arm26 and adapted to impart pivot motion to theswing post28 relative to theswing arm26.
• Thesecond work member20 may comprise atool carrier46. Thetool carrier46 may be constructed to support a variety of alternative work tools. For illustrative purposes, the work tool shown attached to thetool carrier46 inFIG. 1 isloader bucket48. Thetool carrier46 andloader bucket48 are supported by one ormore lift arms50 having a first end52 and asecond end54. Eachlift arm50 is pivotally connected to the secondwork member support56 of theframe12 at pivot point58. Thesecond end54 of thelift arm50 is movable in a range of motion comprising a lower position (shown inFIG. 1) and an upper position. Thelift arm50 may be raised and supported at any position within its range of motion using alift arm actuator60. Thelift arm actuator60 is attached to the secondwork member support56 at pivot point62 and to abracket64 supported at thesecond end54 of the lift arm.
• Thetool carrier46 may comprise a quick-attach mechanism adapted to connect to a wide variety of work tools such as theloader bucket48 shown inFIG. 1. The angular rotational position of thework tool48 may be adjusted or held at a desired “tilt” (“curl”) angle by atilt cylinder66 connected to thetool carrier46 and atilt cylinder bracket68 supported by thelift arm50. It will be appreciated that thelift arm50 may be telescopic at itssecond end54 for extended reach and lift height of thework tool48.
• Continuing withFIG. 1, thework machine10 further may comprise a lowprofile power source70 supported by theframe12. The low-profile power source70 may comprise an internal combustion engine (not shown) supported within anengine compartment76. It will be appreciated, of course, that different type engines or power sources may be used to power thework machine10. Thepower source70 is adapted to drive operation of the left72 and right74 drive systems, and the various hydraulic and electrical systems used with thework machine10. Theengine compartment76 of the low-profile drive system70 is sloped such that a first line-of-sight between thecontrol station22 and thework tool48 is unobstructed when the control station is in position A and the work tool is in the lower position shown inFIG. 1. However, it will be appreciated that thelift arm50 may be constructed in such a manner that a second unobstructed line-of-sight extends from thecontrol station22 to beyond thework tool48 when thesecond end54 of thelift arm50 is in the upper position (not shown).
• Theframe12 is adapted to support a low-profile left72 and right74 (FIG. 5) drive system. The low-profile left72 and right74 drive systems are both supported by the frame for propelling the frame in a plurality of directions. Thedrive systems72 and74 shown inFIGS. 1 and 5 comprise an all-terrain endless track system. However, it will be appreciated that the left72 and right74 drive systems may each comprise a plurality of low-profile wheels that are capable of being steered in a skid, articulated, coordinated or conventional arrangement without departing from the spirit of the invention.
• Referring still toFIG. 1, thepivotal control station22 is supported by theframe12 and may comprise anoperator seat78 having avertical pivot axis80. A plurality of controls82aand82bmay be supported on thecontrol station22 and, more specifically, disposed on the operator'sseat78 for rotation therewith. The controls82aand82bare adapted to control operation of both thefirst work member18 and thesecond work member20.
• Thecontrol station22 may further comprise a roll-over protection structure (“ROPS”)84 supported by theframe12. TheROPS84 is preferably a front-cantilevered canopy having twovertical posts86 and88. Use of the two-post front-cantileveredcanopy ROPS84 provides improved visibility of both thefirst work member18 or thesecond work member20 during the operation of each. Alternatively, the ROPS may have three or more vertical posts or other ROPS structure configurations positioned to allow improved visibility.
• The process of switching the on-seat controls82aand82bfrom functional operation of thefirst work member18 to operation of the second work member20 (or vice versa) will now be described. Switching of operation may be initiated by a function selector switch (not shown). In a first position of the switch, the on-seat controls82aand82boperate a hydraulic circuit powering the above-mentioned drive systems (via a left joystick) while also being available to actuate the movements of the second work member20 (via the right joystick). In the second position of the function selector switch, the on-seat controls82aand82boperate the movements of thefirst work member18. Actuation of the switch causes a pilot pressure controlled diverter valve (not shown) in each of two control valve sections to switch their operative control to thefirst work member18 or to thesecond work member20. Additionally, the switch may cause a seat-mounted valve manifold79 to shift the operative control of the left control82abetween control of thedrive systems72 and74 and control of certain actions of thefirst work member18. The operative control provided by the controls82aand82bare summarized below.
• In accordance with the present invention, there may be two basic modes of operation of thework machine10.Mode 1 involves thesecond work member20 and thedrive systems72 and74, while Mode 2 applies to thefirst work member18. Inoperational Mode 1 the left control82amay operate thedrive systems72 and74 by pilot control of their respective hydrostatic pumps. Forward movement of the left control82acauses thework machine10 to move forward. Rearward movement of the left control82acauses thework machine10 to move rearward. The speed attained by thework machine10 is related to the amount the left control82ais displaced from its neutral position. Charge circuit pressure from one of the hydrostatic pumps flows through the displaced left control82ato control the stroking of each hydrostatic pump. Left-right motion of the left control82acauses thework machine10 to steer in the respective direction. When the left control82ais at either extent of its lateral motion, counter-rotation ofdrive systems72 and74 may cause a zero turning radius to be accomplished in the associated direction.
• Inoperational Mode 1, the right control82bmay operate the actions of thesecond work member20. In this instance (and similar ones described below), the charge circuit pressure flowing through the displaced right control82bcauses the pilot-operated displacement of one or more valve spools in the main control valve. The following description is given for the specific case of thesecond work member20 comprising a loader. Forward and rearward displacement of the control82bfrom its neutral position causes thelift arms50 to raise and lower, respectively. Left and right displacement of the control82bcauses theloader bucket48 to curl upward to contain a payload, or tilt (uncurl) to accept or discharge a payload.
• A toggle switch (not shown) on top of the control82bmay control the flow of hydraulic power to an accessory tool that might be mounted on the first18 or thesecond work member20—for instance a posthole digger, pavement breaker, or the various work tools described hereinafter. The toggle switch may comprise a three-position rocker switch, where the tool activating (ON) position is detented and the opposite OFF position is spring returned to neutral. Whenever an operator is not properly seated in theseat78, an operator presence sensing system in the seat may cause the toggle switch and the controls82aand82bto power down. The system disabling shut-down may be contained within the valve manifold79.
• Continuing withFIG. 1 the second operation mode (Mode 2) will be described with reference to the use of a backhoe assembly for purposes of illustration. The repositioning of the function selector switch will cause the left control82ato operate theboom30, the offsetting action of theswing arm26, and the swing action (side to side pivoting) of theswing post28. Displacement of the control82alongitudinally toward the operator raises theboom30, while pushing away from the neutral position lowers the boom. Displacement of the control82alaterally inward toward the operator causes theswing arm26 to offset thefirst work member18 toward the operator's right, while an outward lateral motion moves theswing arm26 oppositely, for placement of thebucket34 in a desired position on or laterally offset from the longitudinal centerline83 (FIG. 2) of theframe12.
• A toggle switch (not shown) on top of the left control82acontrols pivotal movement of theswing post28 and theboom30 attached thereto. Pressing on the portion of the rocker switch nearest to the operator causes theboom30 to swing toward the operator's right, while pressing on the outer portion moves the boom oppositely.
• In Mode 2, the right control82bcontrols the movement of thedipper32 and thebackhoe bucket34. Displacement of the control82blongitudinally toward the operator causes thedipper32 to move similarly, likewise in the case when moving the control82baway from the neutral position. Displacement of the control82blaterally inward toward the operator causes thebackhoe bucket34 to curl inward toward the operator; an outward lateral motion uncurls the bucket.
• Alternatively, the controls82aand82bcould function electronically. Such a joystick or other type of electronic actuator senses hand-motion direction and distance inputs from the operator and sends correlated electrical signal(s) to a controller, which commands the activation of electro-hydraulic valve(s) and/or the output of variable displacement pump(s). One skilled in the art understands that the output response from a valve or pump is usually hydraulic flow rate, in a response proportional to the input signal. (It is also understood that signals from controls82aand82bcould directly activate electro-hydraulic valves without use of a controller.) An electro-hydraulic valve also typically delivers a hydraulic flow rate to the circuit it controls in proportion to the input signal. Electronic control of selected functions enables their automatic control and eases the switching of control function assignments to suit operator preferences. For example, two common backhoe control patterns are described as ISO and SAE standard control patterns. These could be selected by simply switching the routing of the control signals via a physical switch or by software within the controller.
• The above-mentioned controller may be programmed to automate certain functions of thework machine10. For example, it may be desirable to deposit spoils excavated by the first work member18 a distance from the excavation. Combined pivotal movement of theswing arm26 and theswing post28 can accommodate this desire. The motion-to-function assignments of control82a—lateral motion:swing arm26; toggle switch: swing post28—could be simplified by an operator selectable “coordinated movement” control algorithm. In this operating mode, the coordinated movement of theswing arm26 and theswing post28 could be initiated solely by lateral motion of the operator's left hand. As used here, “coordinated movement” refers to simultaneous or sequential amounts of rotation about the respective pivot axes of the swing arm26 (pivot axis94) and the swing post28 (pivot axis112). Their simultaneous coordinated movement may be in a proportional relationship that is lesser than, greater than, or equal to 1:1. The preferred proportional setting—being site dependent—is one that pivots thefirst work member18 back and forth between the excavation alignment and the spoil pile without need of manually adjusting the angular relationship between theswing arm26 and theswing post28 at either extent of their coordinated movement. This is particularly important at the point of excavation. Theboom30 must be in near parallelism with the desired alignment of the excavation whenever thebackhoe bucket34 is poised to be lowered into the excavation. This can be assured by implementing a “return to dig” subroutine that automatically returns theswing arm26 and theswing post28 to their respective angular orientation equating to the excavation alignment. These two “return to dig” angular parameters can be set or input by the operator by one of several commonly known techniques. For instance, when initially placed in the desired positional alignment, the press of a button could cause recording of readings from angular position sensors (e.g., angular encoders or potentiometers) mounted at the two pivot axes. The controller would bring theboom30 back to this position—after it observes a sequence of electrical control signals representing actions related to lifting, swinging, and opening thebackhoe bucket34 to deposit its contents at the spoil pile—upon the operator's lateral movement of the left control82ain the direction associated with movement toward the excavation. The “return to dig” subroutine would stop the respective angular motions at their set points even though the operator may continue to hold the left control82alaterally displaced. Motion could be stopped prior to reaching these set points by a brief lateral displacement of left control82ain the opposite direction. The “return to dig” subroutine may be utilized separately from the complete “coordinated movement” control cycle. For instance, automated coordinated angular movement of theswing arm26 and theswing post28 directed away from the point of excavation may not be particularly helpful in situations where the desired position and/or elevation for depositing the spoil varies from one cycle to the next, or even less frequently.
• A useful modification (adaptation) of the “return to dig” subroutine is to equally and oppositely coordinate the angular motions of theswing arm26 and theswing post28 whenever they are moved away from coincidence with the longitudinal central axis of thework machine10. In other words, the controller holds all offset positions of thefirst work member18 in parallel alignment with the longitudinalcentral axis83 of theframe12 by utilizing a feedback control loop that continually monitors readings from the two angular position sensors. This “parallel offset” subroutine is particularly advantageous if a trencher or offsetable vibratory plow is attached to theswing arm26. Automated control of parallelism releases the attention of the operator to focus on other important operational tasks. In cases where it is desired that rear work tools of thework machine10 be solely utilized in parallel alignment, a “mechanized” parallel offset could be accomplished without controller automation.
• Turning now toFIG. 2 there is shown a perspective view of theframe12 from itsfirst end14. Theframe12 may be of a box-like construction comprised of several horizontal and vertical plates. Theframe12 may further comprise alongitudinal axis83 comprising amidpoint85. The plates may comprise theoperator platform plate89, a powersource support plate90, a pair ofvertical support plates91 and92, and the second work member supports56. The cross-braced, box-like construction illustrated inFIG. 2 provides torsional rigidity in reacting to the working forces exerted on theframe12 during operation of thework machine10. The use of single plate construction for commonly transferring loads and mounting components contributes to compactness and simplicity of thework machine10.
• Continuing withFIG. 2, theframe12 may also comprise apedestal93 supported on the operator'splatform89 and adapted to support the operator's seat78 (FIG. 1). Thepedestal93 may be disposed coaxially with thevertical pivot axis80 of thecontrol station22. As shown inFIG. 2, thevertical pivot axis80 of the control station22 (FIG. 1) may be disposed along thelongitudinal axis83 of theframe12 such that it intersects the longitudinal axis. Thevertical pivot axis94 of the first work member18 (FIG. 1) is likewise disposed along thelongitudinal axis83 of theframe12 and passes through a yet to be describedfirst work member18 mounting assembly.
• Thevertical side plates91 and92 support the second work member supports56 and agauge panel96. The second work member supports56 may be welded to theouter surface98 ofvertical side plates91 and92. The second work member supports56 may haveopenings101 and102 for mounting thesecond work member20 to theframe12. Thus, when mounted to theframe12, thesecond work member20 comprises a substantiallyhorizontal pivot axis103 disposed in relation to thelongitudinal axis83 of theframe12. InFIG. 2, thehorizontal axis103 is arranged perpendicular to thelongitudinal axis83 of theframe12. It will be appreciated that the box-like construction of the frame allows thepivot axis80 of thecontrol station22, thepivot axis94 of thefirst work member18, and thepivot axis103 of thesecond work member20 to be disposed in relation to each other to create a close-coupled work machine in accordance with the present invention. It will be further appreciated that thepivot axis94 of thefirst work member18 and thepivot axis103 of thesecond work member20 may be disposed such that the axes substantially overlap.
• Thegauge panel96 is shown welded to aninner surface100 of thevertical side plates91 and92. Thegauge panel96 may havecutouts104 of varying size and configurations to accommodate the presence of various gauges and controls.
• Turning now toFIG. 3, there is shown therein a partially cut-away view of theframe12 shown supporting thefirst work member18. Thefirst work member18 is supported between the operator'splatform89 and thepower source plate90. Thefirst work member18 ofFIG. 3 generally comprises theswing arm26 pivotally connected to theframe12 and aswing post28 pivotally connected to theswing arm26. Theswing arm26 is attached to theframe12 by a swingarm mounting pin106 with upper108 and lower110 support bushings. The swing arm cylinder42 (SeeFIG. 1) is connected to theframe12 and theswing arm26 and provides swing force to the swing arm to move it about thepivot axis94. However, it will be appreciated that other mechanisms such as a rotary actuator may be used to provide the swing force used to move theswing arm26 without departing from the spirit of the invention.
• As previously discussed, theswing arm26 has an unimpeded range of offset positions. Theswing arm26 arrangement ofFIG. 3 is bound only by the swing arm's points of contact with thevertical side plates91 and92 and by the extended and retracted range of theswing arm cylinder42. Thepivot axis94 of theswing arm26 is shown for purposes of illustration laterally centered within theframe12 to allow substantially the same amount of offset left or right for thefirst work member18. As will be discussed with reference toFIG. 5, the swing arm's26 range of motion allows theswing arm cylinder42 to pivot theswing post28 and swing arm to a position beyond theleft drive system72 and/or beyond theright drive system74.
• Theswing post28 is supported on theswing arm26 and pivotal aboutpivot axis112. Theswing post28 may comprise several mountingpoints114 and a swingpost cylinder bracket116. The mounting points114 may support the work tool for operation at thefirst end14 of the frame. For example, the mounting points may be adapted to connect theboom30 andcylinder36 of the backhoe assembly to thework machine10. The swingpost cylinder bracket116 extends laterally from theswing post28 and provides a connection point for theswing post cylinder44. The opposing end of thecylinder44 is connected to abracket118 pivotally supported on theswing arm26. Connection of thecylinder44 to theswing arm26 allows the cylinder to impart a pivot motion to theswing post28 relative to the swing arm to either side of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm.
• Turning now toFIG. 4, thework machine10 of the present invention is shown from the top having thework tool34 of thefirst work member18 in a stowed “Position A”. Theswing arm26 is positioned to the left side (operator's right when facing thefirst end14 of the frame12) of thework machine10 and the swing post cylinder44 (FIG. 3) is fully retracted. However, theswing post cylinder44 may be replaced with a conventional rotary actuator swing mechanism (not shown), to increase the range of motion to the stow position of thework tool34 in “Position B”. The “minimum overhang” stow positions shown at Positions A and B improves the functional utilization of thefirst work member18 in space-limited applications. Thefirst work member18 may be stowed with theswing arm26 at the opposite point in its travel, or anywhere in between. The operator may utilize this feature to enhance the side slope stability of thework machine10 while maneuvering around a job site and/or during operations of thesecond work member20. It will be appreciated that the addition of appropriate stability (slope) sensors will allow for automatic altering of the stow position by a control system such as described hereinafter. Alternately, a stow position where theswing arm26 of thefirst work member18 is aligned with thelongitudinal axis83 of theframe12 will offer enhanced counter-balance to the breakout force and lift capacity of thesecond work member20. As previously discussed, theswing arm26 may be moved beyond theleft drive system72 and theright drive system74. However, stowing positions preferably retain theswing arm26 of thefirst work member18 inboard of those boundaries to maintain a narrow lateral profile for thework machine10.
• With reference now toFIG. 5, thework machine10 is shown from the top with theROPS84 cut-away. InFIG. 5 thefirst work member18 is shown in Positions C and D to illustrate the range-of-motion of the first work member when moved by theswing arm cylinder42 andswing post cylinder44. Theswing arm cylinder42 may be utilized to position and hold theswing arm26 laterally (left or right) anywhere within an arc of motion substantially bisected by thelongitudinal axis83 of theframe12.
• A lock (not shown) may be provided to hold theswing arm26 in position once set in a desired operating or stow position. A suitable lock may be, for instance, a hydraulic or otherwise-actuated device such as a frictional clamp (brake), a multi-positional latch, or simply the pinning of thearm26 to theframe12 or the operator'splatform89. Alternately, the swing arm lock could be a closed-loop control system consisting of one or more sensors to determine position of theswing arm26, an operator interface (not shown) for the operator to input the desired position, and appropriate control circuitry and logic. The control system receives the input position signal and activates theswing arm cylinder42 to bring theswing arm26 to the desired position. A “set” signal from the operator would cause the control system to monitor the sensor output(s) and assure thearm26 stays in position by activating theswing arm cylinder42 as may be required to hold the desired position. The stored position point may also be useful for returning theswing arm26 to the same position time after time. This may ease the burden on the operator in the case where cooperative use of theswing arm cylinder42 and theswing post cylinder44 is employed to position the payload discharge of the work tool34 (backhoe bucket) at a point of greater arcuate reach. Suitable position sensors would include a rotary potentiometer on theswing arm26 or a linear motion transducer contained on or within theswing arm cylinder42.
• InFIGS. 5 and 6, the arcuate reach of the boom30 (FIG. 1 and thus that of thefirst work member18—is illustrated as being at least 260 degrees total, 130 degrees either side oflongitudinal axis83 of theframe12. This reach represents the cooperative, combined pivotal motion of theswing arm26 and theswing post28 about their respective pivot axes94 and112. Thefirst work member18 comprising the backhoe assembly can create an excavation in a desired direction within the angular bounds of Position C and Position D, while depositing the excavated spoil at another location within those bounds. It may also create an excavation that is substantially parallel to thelongitudinal axis83 of theframe12 anywhere within the bounds of Position E and Position F ofFIG. 6. The lateral extent (offset) of these two positions is dependent upon the amount of arcuate motion available to theswing post28—through the action of theswing post cylinder44. The offset of Positions E and F are also dependent upon considerations related to theswing arm26 described below.
• Referring still toFIGS. 5 and 6, the arc of motion of theswing arm26 about itspivot axis94 is preferably of a sufficient degree to allow thefirst work member18 to perform its work function(s) along a line substantially parallel to and laterally outside of either the left72 or right74 drive system. At any particular offset alignment, this is accomplished by extending or retractingswing post cylinder44 such that theswing post28 rotates (positions) thework tool34 into parallel (though offset) alignment with thelongitudinal axis83 of theframe12. As illustrated inFIGS. 5 and 6, the full range of motion of theswing arm26 is 130 degrees of arc. This allows work to be performed centered on a line outside of either theleft drive system72 or theright drive system74. Within the bounds of machine stability considerations, the necessary amount of arc is primarily dependent upon the overall width of thedrive systems72 and74, the desired lateral distance outside thedrive systems72 and74 to perform work, and the length of theswing arm26. The overall width of thedrive systems72 and74 might be a single (fixed) value, may have given values for each tread width available for the endless tracks, or—for an adjustable undercarriage—may be of variable width. The arc of motion and length of theswing arm26, including being of a telescoping configuration, may be determined in a tradeoff relationship affected by other design variables, such as available space for supported placement of the swingarm pivot axis94.
• Turning now toFIG. 7, there is shown therein thework machine10 of the present invention excavating a trench shown with dashed lines120. The trench120 is shown offset outside thetrack72 and is parallel to the digging alignment of theboom30, thedipper32, and thebackhoe bucket34.
• Thefirst work member18 may be positioned at the offset position shown inFIG. 7 by pivotal action of theswing post28 and theswing arm26. Once theboom30 is aligned longitudinally parallel to thelongitudinal axis83 of theframe12 by pivotal action of theswing post28 andswing arm26, the excavation proceeds by coordinated actions of theboom30, thedipper32, and thebucket34. Discharge of spoil from thebucket34 may be accomplished by arcuate repositioning of the backhoe through pivotal action of theswing post28 or of theswing arm26. The combined pivotal action of theswing post28 and theswing arm26 may be useful in instances where one desires the spoil pile to be further displaced from the excavation. In the illustration ofFIG. 7, depositing of spoil toward the machine centerline side of the excavation will substantially involve pivotal action of theswing arm26, as theswing post28 may have limited remaining motion available in that direction. Conversely, depositing spoil laterally beyond the excavation will substantially involve pivotal action of theswing post28 since theswing arm26 may already be in a fully offset position. Alternate tools such as a plow (shown inFIG. 11) may be positioned in much the same way as illustrated inFIG. 7—thus allowing the tool to operate beyond theleft drive system72 or theright drive system74. This arrangement is advantageous when working along an obstruction such as a wall.
• Aided by the laterally offsetablefirst work member18, thework machine10 equipped with an independently adjustable width drive system can be “walked” sideways for close maneuvering in tight quarters. With theswing arm26 positioned toward the side of the desired direction of machine sideways movement, toward the left in this example, thebackhoe bucket34 can be pressed downward to lift the left side of themachine10 slightly off the ground while theleft drive system72 is extended. At the same time, theright drive system74 may be extended to move themachine10 toward the left. Theswing arm26 may then be moved to the right (opposite) side of themachine10 to slightly lift theright drive system74. The width of theleft drive system72 may then be narrowed to move themachine10 an additional increment toward the left. Narrowing theright drive system74 at this time brings the drive system back to its starting position or into position for another sideways movement. A width that is simultaneously rather than independently adjustable can also be utilized to walk themachine10 sideways in a similar manner. One skilled in the art can readily modify the above procedure to accommodate the situation where themachine10 initially has its variable width undercarriage fully extended.
• Turning now toFIG. 8, there is shown therein thework machine10 of the present invention with an operator122 seated at thecontrol station22. The operator122 shown inFIG. 8 may be generally characterized as a 95^thpercentile male operator.FIG. 8 illustrates the forward2 visibility of thesecond work member20 and theloader bucket48. The steep forward slant to theengine compartment76 provides the operator122 with an unobstructed line ofsight124 of thebucket48 when thelift arms50 are in the lowered position. The slant of theengine compartment76 approximately parallels the operator's line ofsight124. Adjustment of the operator'sseat78 would further improve visibility. Such an adjustment is practical even forlarger operators78 because of placement of thecontrols82 on the seat, rather than on a console. Perforating a portion of the ROPS84 (FIG. 4) canopy provides the operator122 with improved visibility of thebucket48 when thelift arms50 are in the upper position.
• Positioning of the low-profile power source70 in relation to the operator's line-of sight122 helps to achieve the unobstructed line-of-sight illustrated inFIG. 8. Lower positioning of thepower source70 is accomplished, in part, by driving theleft drive system72 and theright drive system74 at their respective inboard rearward ends. This arrangement provides a clear space between the forward end of theleft drive system72 and theright drive system74, where the lower part of the frame12 (FIG. 2)—i.e., thevertical side plates91 and92 and theengine support plate90—can lay, as illustrated inFIG. 2. For purposes of illustrations, forward ins the direction the operator122 is facing inFIG. 8. An engine-pump assembly (described hereinafter) is disposed between thevertical side plates91 and92 of theframe12, partially nested between theleft drive system72 and theright drive system74. Theengine compartment76 can thus be forward-sloped for improved operator visibility-towards thesecond work member20.
• Side-by-side arrangement of the engine-pump assembly (not shown) within theengine compartment76 shortens the engine compartment and thesecond end16 of theframe12. The second work member supports56 can thus be placed further rearward on theframe12. The shortened first14 and second16 ends of theframe12 are further complemented by a condensed central portion, made possible by the compact length of theoperator platform89. Its compact length is primarily the outcome of utilizing the on-seat controls82 instead of pedestal-mounted controls for the first andsecond work members18 and20.
• Continuing withFIG. 8, the downward sloped shroud of theengine compartment76 is possible because the drive system components (not shown) are mounted low within theframe12, on the power source plate90 (SeeFIG. 2). It will be appreciated that the power train components may comprise an engine-powered hydrostatic pump assembly configured with an axial “stack” of two hydrostatic pumps (one to drive each of theleft drive system72 and the right drive system74) and an auxiliary pump supported along side a rearward-facing engine. The side-by-side arrangement of the engine and hydraulic pumps shortens theengine compartment76 and, likewise, thesecond end16 of theframe12.
• Referring now toFIG. 9, the operator's visibility of thefirst work member18 is illustrated.FIG. 9 depicts thework machine10 with a backhoefirst work member18 near its full digging depth, in alignment with thelongitudinal axis83 offrame12. The operator'sunobstructed view126 of thebackhoe bucket34 is indicated by a dashed line. The openness of theoperator platform89 is particularly apparent with the backhoe assembly in its lowered position. It will be appreciated that the operator'sview126 over theoperator platform89 can be improved by readjusting theseat78 towards thefirst work member18.
• It will be appreciated that the operator's line-of-sight126 remains substantially unobstructed when thefirst work member18 is deployed for excavating parallel to thelongitudinal axis83 of theframe12 outside either of thedrive systems72 and74. Essentially the operator's knees may comprise the only obstruction to his/her view of thebucket34. Thework machine10 offers unobstructed operator visibility of thefirst work member18 in any of its possible working positions shown inFIGS. 5 and 6.
• With reference now toFIG. 10, there is shown therein an alternative configuration of thework machine10 of the present invention. Thework machine10 ofFIG. 10 comprises thefirst work member18 having a backhoe assembly supported thereon and thesecond work member20 comprising a trencher128 supported by thetool carrier46. In this arrangement, themachine10 travels rearward while trenching. The operator may face the operator'sseat78 in that direction, as shown. However, facing theseat78 toward the left or right side of themachine10 offers improved visibility of the trencher128 and the path to be traveled.
• It will be appreciated that one or more tools or work members are suitable for mounting at either end of thework machine10. Although not illustrated, one or more quick-attach mechanisms (tool carrier adapters) could also be configured with thefirst work member18. For instance, a quick-attach mechanism could be mounted between thedipper32 and the rear work tool (backhoe bucket)34. Thebucket34 may then be quickly replaced with other tools or work members suitable for boom-mounting. These may include an offsetable vibratory plow, a trencher128, and other devices such as a compaction wheel, a vibratory compactor, or a pavement breaker. Mounting of trencher128 at the distal end of thedipper32 would allow the trencher to be utilized above or below the ground's surface, and/or at extended lateral reach.
• A quick-attachmechanism130 could also be mounted to theswing post28 to facilitate conversion to a more closely-coupled but offsetable tool, such as thevibratory plow132 shown inFIG. 11. In this case, theswing arm26 in conjunction with the swingable attachment frame134 (and theirhydraulic cylinders42 and44) provides the lateral offset capability. A lifting mechanism (not shown), to raise and lower theplow132, is also contained within theattachment frame134. A similar arrangement may be utilized for supporting a trencher128 from theswing arm26.
• Turning now toFIG. 12, yet another configuration for work machine of the present invention is illustrated. Inwork machine10 ofFIG. 12 thesecond work member20 is shown supporting adump bed136. Thedump bed136 is configured to be located above theengine compartment76 of thework machine10. The contour of the rear lower portion of thedump bed138 is designed to generally follow the contour of theengine compartment76 and liftarms50. This contour and the fact that thedump bed136 is located above theengine compartment76 moves the center of gravity (CG)140 of the dump bed closer to the CG of thework machine10. This allows more weight to be carried in thedump bed136 when moving the load from one location to another, compared to the load that could be carried with a more normal bucket configuration (i.e., further out in front of the machine10).Discharge cylinders142 provide a dumping force to tilt thedump bed136 to allow thematerial144 contained within to be dumped on the ground and to thus empty thedump bed136. During the operation of dumping, theCG140 of thedump bed136 moves forward. To reduce the chance of themachine10 tipping forward, a support plate146 may be lowered to contact the ground by the activation of cylinder(s)148.
• It will be appreciated that thedump bed136 may be detached from the unit by disconnecting the tilt arm cylinder(s)142 and removing attachment pins150. In this arrangement, thedump bed136 may be fitted with at least oneremovable support leg152. The support leg and the base of thebed136 allow the dump bed to sit upright on the ground. In this way thedump bed136 could be filled by another machine or by hand while thework machine10 is being used elsewhere. Alternately, thedump bed136 could be filled by use of thefirst work member18 orsecond work member20. Once filled with material, thedump bed136 may be picked up again by themachine10 and transported to another location to deposit the material. A similar “over theengine compartment76” configuration could be used for some other attachments when additional weight or bulk must be carried—for instance, a flat pallet for carrying sacks or roofing materials, or a concrete transporter.
• Various modifications can be made in the design and operation of the present invention without departing from the spirit thereof. Thus, while the principal preferred construction and modes of operation of the invention have been explained in what is now considered to represent its best embodiments, which have been illustrated and described, it should be understood that the invention may be practiced otherwise than as specifically illustrated and described.

Claims (64)

1. A work machine comprising:

a frame having a first end and a second end;

a first work member supported by the frame so that the first work member is operable at the first end of the frame;

a second work member supported by the frame so that the second work member is operable at the second end of the frame;

a pivotal control station supported by the frame and movable between at least a first position and a second position and adapted to control the first work member when in the first position and to control the second work member when in the second position.

2. The work machine ofclaim 1 wherein the second work member comprises a tool carrier.

3. The work machine ofclaim 2 further comprising a work tool supported by the tool carrier.

4. The work machine ofclaim 1 wherein the first work member comprises a tool carrier and wherein the second work member comprises a tool carrier.

5. The work machine ofclaim 1 wherein the pivotal control station comprises a plurality of controls supported on the control station, the controls being adapted to control operation of the first work member and the second work member.

6. The work machine ofclaim 5 wherein the control station comprises a pivotal operator seat and wherein the plurality of controls are disposed at the operator seat.

7. The work machine ofclaim 1 comprising a low-profile power source supported by the frame.

8. The work machine ofclaim 7 wherein the second work member comprises:

a lift arm having a first end and a second end, the first end being pivotally connected to the frame, and the second end being movable in a range of motion comprising a lower position and an upper position; and

a work tool supported by the second end of the lift arm.

9. The work machine ofclaim 8 wherein the work tool comprises a loader bucket.

10. The work machine ofclaim 8 further comprising:

a first unobstructed line of sight extending from the control station over the low-profile power source to the work tool when the second end of the lift arm is in the lower position; and

a second unobstructed line of sight extending from the control station to beyond the work tool when the second end of the lift arm is in the upper position.

11. The work machine ofclaim 1 further comprising a low-profile left drive system and a low-profile right drive system, both systems being supported by the frame for propelling the frame in a plurality of directions.

12. The work machine ofclaim 11 wherein the left and right drive systems each comprise an endless track.

13. The work machine ofclaim 11 wherein the left and right drive systems each comprise at least two low-profile wheels and wherein the wheels can be steered in a skid arrangement.

14. The work machine ofclaim 11 wherein the first work member comprises:

a swing arm pivotally connected to the frame, the swing arm having a central longitudinal axis;

a swing post pivotally connected to the swing arm;

a swing arm actuator fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions, the plurality of positions including at least one position placing the swing post beyond the left drive system, and at least one position placing the swing post beyond the right drive system; and

a swing post actuator fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm.

15. The work machine ofclaim 1 wherein the frame comprises a longitudinal axis comprising a midpoint; wherein the pivotal control station comprises a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis; wherein the first work member comprises a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis of the frame; and wherein the second work member comprises a substantially horizontal pivot axis disposed near the midpoint of longitudinal axis of the frame.

16. The work machine ofclaim 15 wherein the pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to each other to create a close-coupled work machine.

17. The work machine ofclaim 16 wherein the pivot axis of the first work member and the pivot axis of the second work member substantially overlap.

18. The work machine ofclaim 1 wherein the first work member comprises:

a swing arm pivotally connected to the frame;

a swing post pivotally connected to the swing arm;

a work tool supported by the swing post; and

an unobstructed line of sight extending from the control station to the work tool of the first work member.

19. An excavator comprising:

a frame having a first end and a second end;

a control station supported by the frame;

a low-profile power source supported by the frame;

a first work member supported by the frame so that the first work member is operable at the first end of the frame and operated by the control station;

a second work member supported by the frame so that the second work member is operable at the second end of the frame and operated by the control station, the second work member comprising:

a lift arm having a first end and a second end, the first end being pivotally connected to the frame, and the second end being movable in a range of motion comprising a lower position and an upper position;

a work tool supported by the second end of the lift arm;

a first unobstructed line of sight extending from the control station over the low-profile power source to the work tool when the second end of the lift arm is in the lower position; and

a second unobstructed line of sight extending from the control station to beyond the work tool when the second end of the lift arm is in the upper position.

20-21. (canceled)

22. The excavator ofclaim 19 wherein the control station is movable between at least a first position and a second position and adapted to control the first work member when in the first position and to control the second work member when in the second position.

23. The excavator ofclaim 22 wherein the control station comprises a plurality of controls operatively supported on the control station, the controls being adapted to control operation of the first work member and the second work member.

24-25. (canceled)

26. The excavator ofclaim 19 further comprising a low-profile left drive system and a low-profile right drive system both systems being supported by the frame for propelling the frame in a plurality of directions.

27-28. (canceled)

29. The excavator ofclaim 26 wherein the first work member comprises:

a swing arm pivotally connected to the frame, the swing arm having a central longitudinal axis;

a swing post pivotally connected to the swing arm;

a swing arm actuator fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions, the plurality of positions including at least one position placing the swing post beyond the left drive system, and at least one position placing the swing post beyond the right drive system; and

a swing post actuator fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm.

30. The excavator ofclaim 19 wherein the frame comprises a longitudinal axis comprising a midpoint; wherein the pivotal control station comprises a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis; wherein the first work member comprises a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis of the frame; and wherein the second work member comprises a substantially horizontal pivot axis disposed near the midpoint of the longitudinal axis of the frame.

31. The excavator ofclaim 30 wherein the pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to each other to create a close-coupled work machine.

32. (canceled)

33. The excavator ofclaim 19 wherein the first work member comprises:

a swing arm pivotally connected to the frame;

a swing post pivotally connected to the swing arm;

a work tool supported by the swing post; and

an unobstructed line of sight extending from the control station to the work tool of the first work member.

34. An excavator comprising:

a frame comprising a first end and a second end;

a low-profile left drive system and a low-profile right drive system both supported by the frame for propelling the frame in a plurality of directions;

a first work member supported by the frame so that the first work member is operable at the first end of the frame, the first work member comprising:

a swing arm pivotally connected to the frame and having a central longitudinal axis;

a swing post pivotally connected to the swing arm;

a swing arm actuator fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions, the plurality positions including at least one position placing the swing post beyond the left drive system and at least one position placing the swing post beyond the right drive system; and

a swing post actuator fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm; and

a second work member supported by the frame so that the second work member is operable at the second end of the frame.

35. The excavator ofclaim 34 wherein the first work member comprises a work tool operatively connected to the swing post.

36. The excavator ofclaim 35 wherein the work tool comprises:

a boom connected to the swing post;

a dipper connected to the boom; and

an excavating bucket connected to the dipper.

37. The excavator ofclaim 34 further comprising a pivotal control station supported by the frame and movable between at least a first position and a second position and adapted to control the first work member when in the first position and to control the second work member when in the second position.

38. The excavator ofclaim 37 wherein the pivotal control station comprises a plurality of controls supported on the control station, the controls being adapted to control operation of the first work member and the second work member.

39-47. (canceled)

48. The excavator ofclaim 34 further comprising:

a work tool supported by the swing post; and

an unobstructed line of sight extending from the control station to the work tool of the first work member.

49. A work machine comprising:

a frame having a first end, a second end and a longitudinal axis comprising a midpoint;

a pivotal control station supported by the frame and having a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis;

a pivotal first work member supported by the frame having a substantially vertical pivot axis disposed near the midpoint of the longitudinal axis of the frame; and

a pivotal second work member supported by the frame having a substantially horizontal pivot axis.

50. The work machine ofclaim 49 wherein the pivotal control station is movable between a first position and a second position and adapted to control the first work member when in the first work position and to control the second work member when in the second work position.

51. The work machine ofclaim 49 wherein the pivotal control station comprises a plurality of controls supported on the control station, the controls being adapted to control operation of the first work member and the second work member.

52-55. (canceled)

56. The work machine ofclaim 49 further comprising a low-profile power source supported by the frame.

57. The work machine ofclaim 56 wherein the second work member comprises:

a lift arm having a first end and a second end, the first end being pivotally connected to the frame, and the second end being movable in a range of motion comprising a lower position and an upper position; and

a work tool supported by the second end of the lift arm.

58. (canceled)

59. The work machine ofclaim 57 further comprising:

a first unobstructed line of sight extending from the control station over the low-profile power source to the work tool when the second end of the lift arm is in the lower position; and

a second unobstructed line of sight extending from the control station to beyond the work tool when the second end of the lift arm is in the upper position.

60. The work machine ofclaim 49 further comprising a low-profile left drive system and a low-profile right drive system, both systems being supported by the frame for propelling the frame in a plurality of directions.

61. The work machine ofclaim 60 wherein the first work member comprises:

a swing arm pivotally connected to the frame, the swing arm having a central longitudinal axis;

a swing post pivotally connected to the swing arm;

a swing arm actuator fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions, the plurality of positions including at least one position placing the swing post beyond the left drive system, and at least one position placing the swing post beyond the right drive system; and

a swing post actuator fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm.

62. The work machine ofclaim 49 wherein the pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to each other to create a close-coupled work machine.

63. The work machine ofclaim 49 wherein the first work member comprises:

a swing arm pivotally connected to the frame;

a swing post pivotally connected to the swing arm;

a work tool supported by the swing post; and

an unobstructed line of sight extending from the control station to the work tool of the first work member.

64. (canceled)

65. An excavator comprising:

a frame having a first end and a second end;

a pivotal control station supported by the frame;

a first work member supported by the frame so that the first work member is operable at the first end of the frame, the first work member comprising;

a swing arm pivotally connected to the frame;

a swing post pivotally connected to the swing arm; and

a work tool supported by the swing post;

a second work member supported by the frame so that the second work member is operable at the second end of the frame;

an unobstructed line of sight extending from the control station to the work tool of the first work member.

66. The excavator ofclaim 65 wherein the pivotal control station is movable between at least a first position and a second position and adapted to control the first work member when in the first work position and to control the second work member when in the second work position.

67. The excavator ofclaim 65 wherein the pivotal control station comprises a plurality of controls supported on the control station, the controls being adapted to control operation of the first work member and the second work member.

68. (canceled)

69. The excavator ofclaim 65 further comprising a low-profile power source supported by the frame.

70. The excavator ofclaim 69 wherein the second work member comprises:

a lift arm having a first end and a second end, the first end being pivotally connected to the frame, and the second end being movable in a range of motion comprising a lower position and an upper position; and

a work tool supported by the second end of the lift arm.

71. The excavator ofclaim 70 further comprising:

a first unobstructed line of sight extending from the control station over the low-profile power source to the work tool when the second end of the lift arm is in the lower position; and

a second unobstructed line of sight extending from the control station to beyond the work tool when the second end of the lift arm is in the upper position.

72. The excavator ofclaim 65 wherein the pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to each other to create a close-coupled work machine.

73. A work machine comprising:

a frame having a first end and a second end;

a pivotal control station supported by the frame and having a substantially vertical pivot axis;

a pivotal first work member supported by the frame so that the first work member is operable at the first end of the frame and the first work member comprising a substantially vertical pivot axis;

a pivotal second work member supported by the frame so that the second work member is operable at the second end of the frame and comprises a substantially horizontal pivot axis;

wherein the pivot axis of the control station, the pivot axis of the first work member, and the pivot axis of the second work member are disposed in relation to the frame to create a close-coupled work machine.

74. The work machine ofclaim 73 wherein the pivotal control station is movable between at least a first work position and a second work position and adapted to control the first work member when in the first work position and to control the second work member when in the second work position.

75-76. (canceled)

77. The work machine ofclaim 73 further comprising a low-profile left drive system and a low-profile right drive system, both systems being supported by the frame for propelling the frame in a plurality of directions.

78. The work machine ofclaim 77 wherein the first work member comprises:

a swing arm pivotally connected to the frame, the swing arm having a central longitudinal axis;

a swing post pivotally connected to the swing arm;

a swing arm actuator fixed to the frame and adapted to pivot the swing arm and swing post relative to the frame to a plurality of positions, the plurality of positions including at least one position placing the swing post beyond the left drive system, and at least one position placing the swing post beyond the right drive system; and

a swing post actuator fixed to the swing arm and adapted to impart a pivot motion to the swing post relative to the swing arm to either side of the central longitudinal axis of the swing arm such that the pivot motion of the swing post is not restricted by the position of the swing arm.

79-80. (canceled)

Images