Lawn mower with deck lift system that raises and lowers deck with respect to frame and handle control assembly

Abstract

A lawn mower .[.is provided. In certain example embodiments, the lawn mower.]. includes an improved steering control system/assembly and/or an improved pump control linkage system/assembly. .[.In certain example embodiments, the.]. .Iadd.The .Iaddend.mower includes an engine deck supporting an engine that drives the at least one blade for cutting grass, the engine deck also supporting a first hydraulic pump that controls the right rear drive wheel and a second hydraulic pump that controls the left rear drive wheel. A deck lift system is for raising/lowering the engine deck relative to both a frame of the mower and a handle control assembly.

Claims

1. A lawn mower comprising: at least one cutting blade for cutting grass; a right rear drive wheel and a left rear drive wheel; an engine deck supporting an engine that drives the at least one blade for cutting grass, the engine deck also supporting a first hydraulic pump that controls the right rear drive wheel and a second hydraulic pump that controls the left rear drive wheel; a deck lift system for raising/lowering the engine deck relative to both a frame of the mower and a handle control assembly, the handle control assembly for allowing an operator of the mower to steer the mower by controlling the right and left rear drive wheels independent of one another; wherein the first hydraulic pump that controls the right rear drive wheel is located on a left half portion of the engine deck, and the second hydraulic pump that controls the left rear drive wheel is located on a right half portion of the engine deck; and wherein a first linkage between a right hand control member and the first hydraulic pump includes a first rotatable torsion bar, and a second linkage between a left hand control member and the second hydraulic pump includes a second rotatable torsion bar, and wherein the first and second torsion bars cross one another so as to form an X when viewed from a rear and/or front of the mower.

2. The mower of claim 1, wherein an end of the first torsion bar is supported by a first substantially vertically extending hinge, and an end of the second torsion bar is supported by a second substantially vertically extending hinge, and wherein upper ends of the first and second hinges are pivotally attached to respective substantially vertically oriented supports that are affixed to or are part of the frame of the mower.

3. The mower of claim 1, wherein the first and second torsion bars each form an angle of from about 10 to 50 degrees relative to the horizontal for at least one location of the engine deck.

4. The mower of claim 1, wherein angles formed between the first and second torsion bars in the X vary as a function of the elevation of the engine deck relative to the frame of the mower.

5. The mower of claim 1, wherein the deck lift system lifts and lowers together the engine deck, engine, a cutter deck, and the pumps of the mower.

6. The mower of claim 1, further comprising a foot platform for supporting feet of an operator who may operate the mower from a standing position.

7. The mower of claim 1, further comprising a seat for supporting an operator of the mower.

8. The mower of claim 1, wherein the mower is a zero turning radius mower capable of performing zero radius turns.

9. A zero turning radius lawn mower comprising: at least one cutting blade for cutting grass; a right rear drive wheel and a left rear drive wheel; an engine deck supporting an engine that drives the at least one blade for cutting grass, the engine deck also supporting a first hydraulic pump that controls the right rear drive wheel and a second hydraulic pump that controls the left rear drive wheel so that the mower is a zero turning radius mower capable of performing zero radius turns via the right and left rear drive wheels; a deck lift system comprising a deck lift lever for raising/lowering the engine deck relative to both a frame of the mower and a handle control assembly, the handle control assembly including first and second upright supports and a plurality of steering levers for allowing an operator of the mower to steer the mower by controlling the right and left rear drive wheels independent of one another; wherein the first hydraulic pump that controls the right rear drive wheel is located on a left half portion of the engine deck, and the second hydraulic pump that controls the left rear drive wheel is located on a right half portion of the engine deck; and wherein a first linkage between a right hand control member and the first hydraulic pump includes a first rotatable torsion bar, and a second linkage between a left hand control member and the second hydraulic pump includes a second rotatable torsion bar, and wherein the first and second torsion bars cross one another so as to form an X when viewed from a rear and/or front of the mower.

10. The mower of claim 9, wherein an end of the first torsion bar is supported by a first substantially vertically extending hinge, and an end of the second torsion bar is supported by a second substantially vertically extending hinge, and wherein upper ends of the first and second hinges are pivotally attached to respective substantially vertically oriented supports that are affixed to or are part of the frame of the mower.

11. The mower of claim 9, wherein the first and second torsion bars each form an angle of from about 10 to 50 degrees relative to the horizontal for at least one location of the engine deck.

12. The mower of claim 9, wherein angles formed between the first and second torsion bars in the X vary as a function of the elevation of the engine deck relative to the frame of the mower.

13. The mower of claim 9, wherein the deck lift system lifts and lowers together the engine deck, engine, a cutter deck, and the pumps of the mower.

14. The mower of claim 9, further comprising a foot platform for supporting feet of an operator who may operate the mower from a standing position.

15. The mower of claim 9, further comprising a seat for supporting an operator of the mower.

.Iadd.16. A lawn mower comprising: at least one cutting blade for cutting grass; a right rear drive wheel and a left rear drive wheel; an engine that drives the at least one blade for cutting grass, a first hydraulic pump that controls the right rear drive wheel, and a second hydraulic pump that controls the left rear drive wheel; a deck lift system for raising/lowering the engine relative to both a frame of the mower and a handle control assembly, the handle control assembly for allowing an operator of the mower to steer the mower by controlling the right and left rear drive wheels independent of one another; wherein the first hydraulic pump that controls the right rear drive wheel is located on one half portion of the mower, and the second hydraulic pump that controls the left rear drive wheel is located on the other half portion of the mower; and wherein a first linkage between at least a right hand control member and the first hydraulic pump includes a first rotatable torsion bar that rotates about an axis that extends in a same direction that the first rotatable torsion bar extends, and a second linkage between at least a left hand control member and the second hydraulic pump includes a second rotatable torsion bar that rotates about an axis, and wherein the first and second rotatable torsion bars extend downwardly in different directions, and wherein at least rotation of the first and second rotatable torsion bars controls speed of the respective rear drive wheels. .Iaddend.

.Iadd.17. The mower of claim 16, wherein an end of the first torsion bar is supported by a movable portion of a first hinge support, and an end of the second torsion bar is supported by a movable portion of a second hinge support, and wherein fixed portions of the first and second hinge supports are attached to respective supports that are affixed to or are part of the frame of the mower. .Iaddend.

.Iadd.18. The mower of claim 16, wherein the first and second torsion bars each form an angle of from about 10 to 50 degrees relative to the horizontal for at least one location of the engine during operation of the deck lift system. .Iaddend.

.Iadd.19. The mower of claim 16, wherein the deck lift system lifts and lowers together the engine, a cutter deck, and the pumps. .Iaddend.

.Iadd.20. The mower of claim 16, further comprising a foot platform for supporting feet of an operator who may operate the mower from a standing position. .Iaddend.

.Iadd.21. The mower of claim 16, wherein the first and second rotatable torsion bars cross each other during at least some normal operations of the mower. .Iaddend.

.Iadd.22. The mower of claim 16, wherein the first and second rotatable torsion bars cross each other in a manner to form an X shape. .Iaddend.

.Iadd.23. The mower of claim 16, wherein the pumps are mounted on an engine deck, and wherein lower ends of the torsion bars raise and lower together with the engine deck when the engine is lifted/lowered by the deck lift system. .Iaddend.

.Iadd.24. A lawn mower comprising: at least one cutting blade for cutting grass; a right rear drive wheel and a left rear drive wheel; an engine that drives the at least one blade for cutting grass, at least one support structure that supports a first hydraulic pump that controls the right rear drive wheel and a second hydraulic pump that controls the left rear drive wheel; a deck lift system for raising/lowering the engine relative to both a frame of the mower and a handle control assembly, the handle control assembly for allowing an operator of the mower to steer the mower by controlling the right and left rear drive wheels independent of one another; wherein a first linkage between at least a right hand control member and the first hydraulic pump includes a first rotatable torsion bar that rotates about an axis that extends in a same direction that the first rotatable torsion bar extends, and a second linkage between at least a left hand control member and the second hydraulic pump includes a second rotatable torsion bar that rotates about an axis that extends in a same direction that the second rotatable torsion bar extends, and wherein each of the first and second rotatable torsion bars has an upper end and from the upper end extends at least downwardly to a lower end that operatively connects to the corresponding pump, and wherein at least rotation of the first and second rotatable torsion bars controls speed of the respective rear drive wheels. .Iaddend.

.Iadd.25. The mower of claim 24, wherein a first pump control rod is provided to operatively link an end portion of the first torsion bar and the first pump, and a second pump control rod is provided to operatively link an end portion of the second torsion bar and the second pump, and an end of the first torsion bar is supported by a first hinging support and an end of the second torsion bar is supported by a second hinging support. .Iaddend.

.Iadd.26. The mower of claim 24, wherein the first and second torsion bars each form an angle of from about 10 to 50 degrees relative to the horizontal for at least one location of the engine. .Iaddend.

.Iadd.27. The mower of claim 24, wherein the deck lift system lifts and lowers together the engine, a cutter deck, and the pumps. .Iaddend.

.Iadd.28. The mower of claim 24, further comprising a foot platform for supporting feet of an operator who may operate the mower from a standing position..Iaddend.

.Iadd.29. The mower of claim 24, wherein hoses between the first pump and a motor for the right rear drive wheel, and hoses between the second pump and a motor for the left rear drive wheel, cross each other. .Iaddend.

.Iadd.30. The mower of claim 24, wherein an angle at which the first rotatable torsion bar is oriented relative to an upper surface of an engine deck changes when the engine deck is raised/lowered, and an angle at which the second rotatable torsion bar is oriented relative to the upper surface of the engine deck changes when the engine deck is raised/lowered. .Iaddend.

.Iadd.31. The mower of claim 24, wherein pivots at the upper ends of the respective first and second rotatable torsion bars change elevation with respect to pivots at lower ends of the respective first and second torsion bars when an engine deck is raised/lowered via the deck lift system. .Iaddend.

.Iadd.32. A lawn mower comprising: at least one cutting blade for cutting grass; a right rear drive wheel and a left rear drive wheel; an engine that drives the at least one blade for cutting grass, at least one support structure that supports a first hydraulic pump that controls the right rear drive wheel and a second hydraulic pump that controls the left rear drive wheel; a deck lift system for raising/lowering the engine relative to both a frame of the mower and a handle control assembly, the handle control assembly for allowing an operator of the mower to steer the mower by controlling the right and left rear drive wheels independent of one another; wherein a first linkage between at least a right hand control member and the first hydraulic pump includes a first rotatable torsion member that rotates about an axis that extends in a same direction that the first rotatable torsion member is oriented, and a second linkage between at least a left hand control member and the second hydraulic pump includes a second rotatable torsion member that rotates about an axis that extends in a same direction that the second rotatable torsion member is oriented, and wherein each of the first and second rotatable torsion members are operatively connected to the corresponding pump, and wherein at least rotation of the first and second rotatable torsion members controls speed of the respective rear drive wheels. .Iaddend.

.Iadd.33. The mower of claim 32, wherein the first and second torsion members comprise respective bars that each form an angle of from about 10 to 50 degrees relative to the horizontal for at least one location of the engine. .Iaddend.

.Iadd.34. The mower of claim 32, wherein the deck lift system lifts and lowers together the engine, a cutter deck, and the pumps. .Iaddend.

.Iadd.35. The mower of claim 32, further comprising a foot platform for supporting feet of an operator who may operate the mower from a standing position. .Iaddend.

.Iadd.36. The mower of claim 32, wherein pivots at the upper ends of the respective first and second rotatable torsion members change elevation with respect to pivots at lower ends of the respective first and second torsion members when an engine deck is raised/lowered via the deck lift system. .Iaddend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a conventional lawn mower including a deck lift system.

(2) FIG. 2 is a side plan view of the mower of FIG. 1.

(3) FIG. 3 is a top view of the mower of FIGS. 1-2.

(4) FIG. 4 is a schematic diagram illustrating certain components of the mower of FIGS. 1-3.

(5) FIG. 5 is a perspective view of components of a steering to and/or pump control assembly/system according to an example embodiment of this invention (the system for only the right rear drive wheel control is illustrated in this figure for purposes of simplicity).

(6) FIG. 6 is a perspective view of certain components of the is steering and/or pump control assembly/system (parts for the system for only the left rear drive wheel control are illustrated in FIG. 6 for purposes of simplicity).

(7) FIG. 7 is a front plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-6 (this view illustrating the system when the engine deck is in a relatively low position relative to the mower's frame—viewed from the front of the mower).

(8) FIG. 8 is a front plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-7 (this view differs from FIG. 7 in that the dash has been removed to permit more parts to be seen) (this view illustrating the system when the engine deck is in a relatively low position relative to the mower's frame).

(9) FIG. 9 is a side plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-8 (this view illustrating the system when the engine deck is in a relatively low position relative to the mower's frame, in the same position as in FIGS. 7-8).

(10) FIG. 10 is a front plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-9 (this view illustrating the system when the engine deck is in a relatively high position, compared to the engine deck position of FIGS. 7-9, relative to the mower's frame—viewed from the front of the mower).

(11) FIG. 11 is a front plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-10 (this view differs from FIG. 10 in that the dash has been removed to permit more parts to be seen) (this view illustrating the system when the engine deck is in a relatively high position, compared to the engine deck position of FIGS. 7-9, relative to the mower's frame).

(12) FIG. 12 is a side plan view of certain components of the steering and/or pump control assembly/system of FIGS. 5-11 (this view illustrating the system when the engine deck is in a relatively high position relative to the mower's frame, in the same position as in FIGS. 10-11).

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

(13) Referring more particularly to the accompanying drawings in which like reference numerals indicate like parts throughout the several views.

(14) The mowers of certain example embodiments of this invention discussed herein may be the same as the mower discussed above with respect to FIGS. 1-4 except for the changes illustrated in the figures herein and/or described herein. .[.As.]. .Iadd.Similar to the mowers .Iaddend.shown in FIGS. 1-4, mowers according to certain example embodiments of this invention are zero radius turning self-propelled power lawn mowers. This mower includes first and second hydro pumps for controlling first and second corresponding wheel motors, so that the first and second rear drive wheels .[.43.]. may be driven independently in order to conduct zero radius turns as discussed above. The mower further includes: independently drivable rear drive wheels .[.43.].; cutter deck assembly .[.12.]. below which the cutting blades cut grass; front caster wheels.[.37.].; foot platform .[.9.]. for supporting feet of a standing or sitting operator; optional seat.[.1.].; gas tank supports .[.80.]. for supporting respective gas tanks; battery housing structure .[.81.]. for housing a battery .[.30.]. and which also functions to help support the seat assembly; steering control levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.(which work in conjunction with rigid hand grip bar .[.32.].) which allow the rear drive wheels .[.43.]. to be independently drivable in opposite directions at the same time so as to enable the mower to perform zero radius turns about a vertical zero radius turning axis; vertically extending support plates or weldments .[.14.]. .Iadd.14′ .Iaddend.which support console/dash .[.36.]. and handle grips .[.32-34.]. .Iadd.33′-34′.Iaddend.; and deck lift lever .[.82.]. which allows the cutter deck assembly .[.12.]. together with the engine deck .[.31.]. .Iadd.31′ .Iaddend.(the combustion engine is mounted on the engine deck .[.31.]..Iadd.31′.Iaddend.) to be raised/lowered, wherein the engine and cutter decks are raised/lowered together as one unit by the deck lift system in order to adjust the height of the mower cut. With respect to the deck lift system which raises/lower the decks (and the hydro pumps mounted on the engine deck), when deck lift lever .[.82.]. is pulled upwardly, the cutter deck assembly .[.12.]. together with the engine deck .[.31.]. .Iadd.31′ .Iaddend.(and engine and hydro pumps) is raised so as increase the height of the mower cut. Direction “h” in FIG. 5 illustrates the direction that the engine deck .[.31.]. .Iadd.31′.Iaddend., engine, cutter deck, and pumps move when raised/lowered by the deck lift system. Chain linkage .[.83.]. suspends the deck assembly .[.12.]. and .[.31.]. .Iadd.31′ .Iaddend.and permits it to be raised and lowered in accordance with the position of lever .[.82.].. The mower and engine decks are raised/lowered relative to the frame of the mower. Thus, the frame of the mower is not raised/lowered with the decks. The frame of the mower includes vertical weldments/supports .[.14.]. .Iadd.14′.Iaddend., as well as the tractor frame which includes components .[.23a, 23b, 23c, 23d and 23e,.]. as well as the vertical sidewalls at the sides of the foot platform (the weldments/supports .[.14.]. .Iadd.14′ .Iaddend.are attached to the tractor frame). Thus, the vertical weldments/supports .[.14.]. .Iadd.14′ .Iaddend.and the handle control assembly .[.32-34.]. .Iadd.33′-34′ .Iaddend.supported by .[.14.]. .Iadd.14′ .Iaddend.do not go up and down along with the decks when the cut height is changed.

(15) The cutter deck assembly .[.12.]. includes a cutter deck below which the grass cutting blades are mounted, a pulley system housing that is covered by a lid to house pulleys and belts for driving the cutting blades. The mower's combustion engine (mounted on engine deck .[.31.]. .Iadd.31′ .Iaddend.and having a shaft extending through and/or below an aperture defined in the engine deck .[.31).]. .Iadd.31′.Iaddend.) drives the belts under the cutter deck lid thereby driving the cutting blade(s) of the mower so that grass can be cut.

(16) FIGS. 5-12 illustrate an improved handle/pump control system or assembly for use with such a mower according to an example embodiment of this invention. FIG. 5 is a perspective view of components of the steering and/or pump control assembly/system (illustrating the right rear drive wheel control system only for purposes of simplicity), whereas FIG. 6 is a perspective view of certain components of the steering and/or pump control assembly/system (illustrating components of the left rear drive wheel control system only for purposes of simplicity). FIGS. 7-9 are various views of parts of the steering and/or pump control assembly/system when the engine deck is in a relatively low position relative to the mower's frame. FIGS. 10-12 are various views of parts of the steering and/or pump control assembly/system illustrating the system when the engine deck is in a relatively high position, compared to the lower engine deck position of FIGS. 7-9, relative to the mower's frame.

(17) Referring to FIGS. 5-12, the handle/pump control system or assembly includes vertically upright supports or weldments .[.14.]. .Iadd.14′ .Iaddend.which support the handle control assembly, rigid handle bar.[.32.]., right hand handle control member .[.100.]. .Iadd.100′ .Iaddend.which includes a front handle control lever .[.33.]. .Iadd.33′ .Iaddend.and a rear handle control lever .[.34.]. .Iadd.34′ .Iaddend.affixed to rotatable horizontal bar 35a, wherein the right hand levers .[.33.]. .Iadd.33′ .Iaddend.and .[.34.]. .Iadd.34′ .Iaddend.are adapted to be moved or gripped by a right hand of the mower operator (the right hand control member .[.100.]. .Iadd.100′ .Iaddend.and the levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.thereof control the speed and driving direction of the right rear drive wheel .[.43.]. of the mower), left hand handle control member 102 which includes a front handle control lever .[.33.]. .Iadd.33′ .Iaddend.and a rear handle control lever .[.34.]. .Iadd.34′ .Iaddend.affixed to rotatable horizontal bar 35b, wherein the left hand levers .[.33.]. .Iadd.33′ .Iaddend.and .[.34.]. .Iadd.34′ .Iaddend.are adapted to be moved or gripped by a left hand of the mower operator (the left hand control member 102 and the levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.thereof control the speed and driving direction of the left rear drive wheel .[.43.]. of the mower), right hand control rod 104 which is oriented substantially vertically and whose up/down movement in direction “b” (see “b” in FIG. 5) is caused by pivoting of the levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.of the right hand control member .[.100.]. .Iadd.100′ .Iaddend.in direction “a” (see “a” in FIG. 5) about the axis of bar 35a, similar left hand control rod 106 which is oriented substantially vertically (i.e., vertically plus/minus about 20 degrees in any direction) and whose up/down movement in direction “b” (see “b” in FIG. 6) is caused by pivoting of the levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.of the left hand control member 102 about the axis of bar 35b, elongated hinges 108 on both the right and left hand sides of the mower, static upper hinge swivel points 110, 112 for each of the two hinges 108, crossing torsion rods 114 and 116 where right wheel torsion rod 114 rotates in direction “f” (see “f” in FIG. 5) controls the right rear drive wheel .[.43.]. of the mower and is rotated when right hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.of right hand control .[.100.]. .Iadd.100′ .Iaddend.are pivoted and left wheel torsion rod 116 controls the left rear drive wheel .[.43.]. of the mower and is rotated when left hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.of left hand control 102 are pivoted, floating (floating relative to the mower's frame) lower hinge swivel points 118, 120 for each of the two hinges 108 which permit the torsion bars to pivot/swivel relative to the lower portions of the hinges, hydraulic (or hydro) pump 122 for controlling the right rear drive wheel .[.43.]. of the mower (but located on the left side of the engine deck .[.31).]. .Iadd.31′.Iaddend., a similar hydraulic pump (see 123 in FIG. 6) positioned over hole 124 in the engine deck .[.31.]. .Iadd.31′ .Iaddend.for controlling the left rear drive wheel .[.43.]. of the mower (but located on the right side of the engine deck .[.31).]. .Iadd.31′.Iaddend., pump control lever 126 for pump 122 that controls the right rear drive wheel .[.43.]. and pivots about pump pivot point 127, pump control lever 128 for the other pump 123 that controls the left rear drive wheel.[.43.]., substantially vertically oriented pump control rods 126a and 128a which move up/down in direction “g” for the corresponding pumps and which are pivotally attached to the pump levers 126, 128, floating pump control rod swivel points .[.130.]. .Iadd.130′ .Iaddend.at upper portions of the pump control rods 126a, 128a, and static swivel points 132 about which levers 134 pivot.

(18) Direction “e” in FIG. 5 depicts substantially horizontal movement of the torsion bar 114 and the bottom of hinge 108 as the engine deck .[.31.]. .Iadd.31′ .Iaddend.(and the engine, and pump 122) move up/down relative to the mower's frame via the deck lift system. In this same respect, “c” and “d” in FIG. 5 depict rotation or pivoting of the hinge 108 at a top portion thereof relative to the vertical support .[.14.]. .Iadd.14′ .Iaddend.thereby allowing the bottom portion of the hinge 108 to move in direction “e” thus permitting the system to compensate for up/down movement of the engine deck, pumps and engine via the deck lift system. FIG. 5 illustrates the control system for the right rear drive wheel.[.43.]., for purposes of simplicity; and the control system for the left rear drive wheel .[.43.]. is identical to that shown in FIG. 5 except that the respective parts are on the other side (e.g., right vs. left, or vice versa) of the mower. FIG. 6 illustrates only parts of the control system for the left rear drive wheel.[.43.]., again for purposes of simplicity.

(19) The right hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.pivot independently from the left hand levers .[.33-34.]. .Iadd.33′-34′.Iaddend.. In other words, movement of the right hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.does not result in movement of the left hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.. It is noted that rotating cross bar 35 includes first and second sections 35a and 35b which are axially aligned but rotate independently of one another, the first section 35a rotating with the right hand levers .[.33-34.]. .Iadd.33′-34′ .Iaddend.and the second section 35b rotating with the left hand levers .[.33-34.]. .Iadd.33′-34′.Iaddend.. Thus, the right and left hand control rods 104 and 106 also move up/down independently of each other. While only one hydro pump 122 is shown in the FIG. 5, another hydro pump 123 (see FIG. 6) is mounted on the engine deck .[.31.]. .Iadd.31′ .Iaddend.over hole 124 in a similar manner for controlling the other drive wheel. Example hydraulic pumps are described in U.S. Pat. No. 6,782,797, the disclosure of which is hereby incorporated herein by reference. First and second hydraulic fluid hoses 140, 142 (see FIG. 6) extend between each pump 122, 123 and the motor that drives the corresponding rear drive wheel .[.43.]. of the mower, and for a given drive direction one of these hoses taking fluid to the motor from the pump, and the other hose taking fluid from the motor to the pump 122 (the pump flow directions change when the driving direction of the motor changes).

(20) Accordingly, it will be appreciated that in the system of FIGS. 5-12, the right handle control .[.100.]. .Iadd.100′ .Iaddend.controls the right rear drive wheel.[.43.]., but the hydro pump 122 for this drive wheel is on the left side of the mower (i.e., on the opposite side of a conventional mower). In a similar manner, the left handle control 102 controls the left rear drive wheel.[.43.]., but the hydro pump 123 for this drive wheel is on the right side of the mower (i.e., on the opposite side of a conventional mower). The driving of the rear drive wheels by respective hydro pumps which are on the opposite sides of the mower than the wheels they drive is implemented by way of the use of torsion bars 114 and 116 that extend downwardly from the handles and “cross” each other to form an X as viewed from the front or rear of the mower (e.g., see FIGS. 7-8 and 10-11). The shape of the X formed by the crossing of the rotatable torsion bars 114 and 116 changes depending on the position of the engine deck .[.31.]. .Iadd.31′ .Iaddend.(and thus the pumps supported by the engine deck, and the cutter deck) (e.g., whether the engine deck is in a raised or lowered position as determined by the deck lift system); compare the X shown in FIGS. 7-8 where the engine deck .[.31.]. .Iadd.31′ .Iaddend.is in a fairly low position versus the X shown in FIGS. 10-11 where the engine deck .[.31.]. .Iadd.31′ .Iaddend.is in a higher position relative to the mower frame and weldment/support .[.14.]. .Iadd.14′.Iaddend.. In other words, the angles of the torsion bars relative to the vertical and horizontal change as a function of the height of the engine deck .[.31.]. .Iadd.31′.Iaddend.. The angles of both torsion bars 114 and 116 change together when the engine deck .[.31.]. .Iadd.31′ .Iaddend.is raised/lowered because the bottom ends of both torsion bars are operatively associated with, or attached indirectly, to the engine deck .[.31.]. .Iadd.31′.Iaddend.. In other words, for each torsion bar 114 and 116, the pivots at the upper end of the torsion bar changes elevation with respect to the pivots at the lower end of the torsion bar when the deck .[.31.]. .Iadd.31′ .Iaddend.is raised/lowered via the deck lift system. Thus, the hand controls .[.32-34.]. .Iadd.33′-34′ .Iaddend.and pumps 122, 123 can move vertically relative to one another, and the system is able to accommodate height change and still transmit the motion proportional to hand levers to control the pumps. In certain example embodiments, the pump levers 126 and 128 face opposite directions (so as to control one pump from the back and one from the front), thereby allowing one torsion bar to be located ahead of the other torsion bar.

(21) This X (i.e., the crossing of the torsion bars for the respective pumps 122 and 123) permits the system to avoid the use of flexible cables in a system where the engine deck can be raised/lowered relative to the frame and handle controls. This is advantageous because flexible cables can be inefficient with respect to transmitting motion, and can introduce inefficiencies into the system.

(22) Referring especially to FIGS. 5-12, an example operation of the steering/pump control system will now be described. When an operator of the mower pulls backward on either of levers .[.33, 34.]. .Iadd.33′, 34′ .Iaddend.of the right hand drive wheel control .[.100.]. .Iadd.100′ .Iaddend.shown in FIG. 5, the right hand control .[.100.]. .Iadd.100′ .Iaddend.(including levers .[.33, 34.]. .Iadd.33′, 34′ .Iaddend.which move together) pivots/rotates clockwise about a horizontal axis defined by bar 35a (“clockwise” is determined as viewed from the port side of the mower—namely from the viewpoint shown in FIG. 5). Such pulling backward on lever .[.33.]. .Iadd.33′ .Iaddend.and/or .[.34.]. .Iadd.34′ .Iaddend.of right rear drive wheel control .[.100.]. .Iadd.100′ .Iaddend.causes the right rear drive wheel to either reduce its forward speed, or to start movement in reverse or increase speed in reverse (in a similar manner, pushing forward on lever .[.33.]. .Iadd.33′ .Iaddend.and/or .[.34.]. .Iadd.34′ .Iaddend.of the right rear drive wheel control .[.100.]. .Iadd.100′ .Iaddend.causes the right rear drive wheel to either increase forward speed, or reduce reverse speed). When levers .[.33, 34.]. .Iadd.33′, 34′ .Iaddend.is/are pulled back and the right rear drive wheel control .[.100.]. .Iadd.100′ .Iaddend.rotates clockwise in direction “a” as shown in FIG. 5, this causes right hand control rod 104 to move upwardly in direction “b” due to the pivotal connection at .[.101.]. .Iadd.101′ .Iaddend.between the control .[.100.]. .Iadd.100′ .Iaddend.and rod 104. When right hand control rod 104 moves upwardly in direction “b”, this causes torsion bar 114 to rotate counterclockwise about its own elongate axis in direction “f” shown in FIG. 5 (again, counterclockwise is determined as viewed from the port side of the mower). This counterclockwise rotation/pivoting of torsion bar 114 in turn causes lever 134 connected thereto to pivot counterclockwise about a horizontal axis defined at 132 which causes the lever 134 to raise pump control rod 126a vertically in direction “g.” This rising of the pump control rod 126a causes the pump control lever 126 to pivot counterclockwise about the pump's axis 127 thereby controlling the pump 122 to either cause the right rear drive wheel .[.43.]. to reduce its forward speed, or to start movement of the wheel in reverse or increase its speed in reverse. Hoses (e.g., see hoses 140, 142 in FIG. 6) from the pump 122 control the wheel motor of the right rear drive wheel .[.43.]. in a known manner. Movement forward of the levers .[.33, 34.]. .Iadd.33′, 34′ .Iaddend.causes the components to move in the opposite directions described. Moreover, the control system of the left rear drive wheel (e.g., see FIG. 6) functions in a similar manner.

(23) The example embodiment illustrated in FIGS. 5-12 utilizes torsion bars 114 and 116 that cross and form a variable “X” when viewed from the rear and/or front of the mower. However, this invention is not so limited. In other example embodiments, the torsion bard 114, 116 may still form an angle of from about 10 to 50 degrees with the horizontal as in the FIG. 5-12 embodiment, but instead extend for/aft within the footprint of the mover (instead of left-right across the width of the mower) in which case the rotatable torsion bars need not cross each other when viewed from the front or rear of the mower.

(24) In the example non-limiting embodiment discussed above, the left pump controls the right drive wheel, and the right pump controls the left drive wheel. However, this invention is not so limited. According to an alternative embodiment of this invention, movement of the right control .[.100.]. .Iadd.100′ .Iaddend.could cause vertical movement of the left control rod 106, while movement of the left control 102 causes movement of the right control rod 104. The same torsion bars and so forth would still be used. In this alternative embodiment, this would permit the left pump to control the left drive wheel, and the right pump to control the right drive wheel.

(25) While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.