Abstract: A system including a gearbox and a hydraulic machine connected by a working fluid circuit. The gearbox including a gearbox housing having first and second gearbox fluid passages integrated into the gearbox housing. The hydraulic machine including a case having first and second hydraulic machine fluid passages, the first and second hydraulic machine fluid passages being integrated into the case. A set of rotating elements enclosed within the case. The first gearbox fluid passage and the first hydraulic machine fluid passage align to form a feed passage to conduct fluid at a first pressure from a first source to the set of rotating elements. The second gearbox fluid passage and the second hydraulic machine fluid passage align to form a charge passage to conduct fluid at a second pressure from a second source to the set of rotating elements. The first pressure being less than the second pressure.

Abstract: Methods for autonomous operation of harvesters use header drive pump displacement, header speed, harvester ground speed, engine load and engine speed to control and maximize harvester operation under varying conditions such as crop type, crop condition and terrain. Adaptive learning processes within the methods relate the parameters of pump displacement with header speed and engine speed during harvester operation to permit the control system to establish combinations of related control parameters which are used by a control system to control harvester operation.

Abstract: Steered caster wheel systems that include a disengagement system to enable a caster wheel steering mode and non-caster wheel steering mode are disclosed. In some embodiments, the caster wheels are mounted to a subframe that may be independently suspended from the chassis of a vehicle such as a self-propelled vehicle.

Abstract: Power machines such as excavators with control inputs that are configurable to control various functions on the excavator. In some modes, selected control inputs are manipulable to control the position of a lift arm, bucket, and house position. In other modes, the same control inputs are used to control travel and an implement on an undercarriage.

Abstract: A plug-compatible interface between a car and its human and/or computer driver makes both car and driver a “black box”, or abstraction, to the other. The two black boxes can then be developed and built independently before being integrated together only at the final stage. Designers on both the car and driver sides of the interface need design only to the interface and need not worry about how things are done on the other side of it. When cars and computer drivers are built to interact over a plug-compatible interface, any computer driver works with any car. If a computer driver becomes outdated, it can be updated or replaced much more quickly and cheaply than replacing the entire car.

Abstract: An all-terrain vehicle is disclosed having a braking system with an anti-lock braking control module and a first brake master cylinder hydraulically coupled to the anti-lock braking control module. A first brake actuator is coupled to the first brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The first brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. A second brake master cylinder is hydraulically coupled to the anti-lock braking control module. A second brake actuator is coupled to the second brake master cylinder and a brake caliper is coupled to at least some of the ground engaging members. The second brake master cylinder upon actuation provides anti-lock braking to either the first or second ground engaging members. The vehicle also has a speed monitor with a gear ring positioned on an exterior surface of a stub shaft and a speed pickup positioned adjacent to the gear ring.

Abstract: A pneumatic engine includes first and second pneumatic motors. Each motor has a stator, a rotor, and a gas flow path. The rotor is rotatably connected to the stator. The gas flow path is defined at least in part by the stator and the rotor, and extends from a gas inlet to a terminal gas outlet. The gas flow path has an expansion portion extending between the gas inlet and an intermediate gas outlet, and a compression portion extending between the intermediate gas outlet and the terminal gas outlet. The terminal gas outlet of the first pneumatic motor is fluidly connected upstream of the gas inlet of the second pneumatic motor.

Abstract: A pneumatic engine includes a plurality of pneumatic motors and an engine drive shaft. Each motor has a motor gas inlet, a motor gas outlet, and a rotor driven by gas flow between the motor gas inlet and the motor gas outlet. The engine drive shaft is drivingly coupled to the motor drive shaft of each of the pneumatic motors.

Abstract: A selectable flow divider drive system includes a hydraulic fluid reservoir and a plurality of drive motors in fluid communication with the hydraulic fluid reservoir. A hydraulic pump is connected between the hydraulic fluid reservoir and the plurality of drive motors and directs hydraulic fluid from the hydraulic fluid reservoir to the plurality of motors. The hydraulic pump is operable in a high flow condition and a low flow condition. A flow divider component is interposed between the hydraulic pump and the plurality of motors. The flow divider component selectively divides hydraulic fluid flow to each of the plurality of drive motors, where a flow divider of the flow divider component is sized for the low flow condition of the hydraulic pump. A bypass valve is disposed upstream of the flow divider that selectively bypasses the flow divider when the hydraulic pump is operated in the high flow condition.

Abstract: A zero-turn mower with selective steering control. The zero-turn mower includes a pair of front wheels having sprockets operably connected thereto, a drive gear rotatably disposed within a housing affixed to the mower frame, and a drive chain that couples the sprockets to the drive gear. A plate gear is slidably disposed on the frame. A pair of actuator arms bias the plate gear rearward to a first position. A pair of pedals can be depressed simultaneously to move the plate gear forward to a second position. When the plate gear is in the first position the drive gear is disengaged, and the front wheels may turn freely to any direction. When the plate gear is in the second position the drive gear engages, and the pedals allow the user to control the direction of the front wheels, allowing the mower to be safely utilized on sloped terrain.

Abstract: A steering system which is capable of being controlled by a redundant brake system, which includes a primary brake control module, a secondary brake control module, and a plurality of brake units controlled by the primary brake control module or the secondary brake control module. There is at least one hydraulic motor connected to a component of the steering system, and the fluid pressure in the hydraulic motor is controlled by the secondary brake control module. The wheels of the steering system are configured to make a right-hand turn when the secondary brake control module operates the hydraulic motor during a first mode of operation, and the wheels of the steering system are configured to make a left-hand turn when the secondary brake control module operates the hydraulic motor during a second mode of operation.

Abstract: A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a tank, a pump, a swing motor, and at least one control. The hydraulic control system may further have an accumulator configured to receive fluid from and supply fluid to the swing motor, a charge valve movable to allow fluid flow from the swing motor into the accumulator, and a discharge valve movable to allow fluid flow from the accumulator to the swing motor. The hydraulic control system may additionally have a controller in communication with the at least one control valve, the charge valve, and the discharge valve. The controller may be configured to detect an acceleration of the swing motor, selectively cause the discharge valve to assist the acceleration, and selectively move the charge valve to an open position to recover energy associated with pressure spikes occurring during the acceleration.

Abstract: A system and method for brake assisted turning are provided. One system includes a pedal operated braking system configured to apply hydraulic brake pressure to brakes of a vehicle when one or more brake pedals are pressed. The system also includes a steer assist braking system configured to apply hydraulic brake pressure to the brakes of the vehicle based at least partly on a steering angle. The system includes hydraulic shut-off circuitry configured to selectively enable and disable operation of the steer assist braking system.

Abstract: A tractor has hydraulically driven wheels at a cab end and castor wheels at an engine end. Each driven wheels is driven by a hydraulic motor with a continuous adjustment of the motor displacement, with the motor being driven by a pump also having continuous displacement. The motor displacement is controlled by an electronic controller in response to stroking of the speed control lever to manage the displacement to provide required drive torques at different points in the stroke. There is provided an automatic steering system having a guidance controller arranged to receive GPS position information which controls the steering by differentially adjusting the displacement of the motors so that the automatic steering is independent of the manual steering which controls the pumps.

Abstract: An integrated steering control system includes a primary, automatic and rear control valves. A steering wheel operates the primary steering control valve and is of a type which includes a leakage characteristic. Steering wheel movement is sensed and a signal is sent which results in the automatic steering control valve being operated for adding fluid that supplied to a steering cylinder by the primary steering control valve in order to compensate for leakage, the amount of added fluid being a function of vehicle ground speed. An electric actuator with position feedback is used for ground speed control. Whenever the actuator position shows that the ground speed is set to zero and a switch in the hydro-handle slot shows that the handle is in the Park position, the automatic steering control valve is activated to move the steering cylinder to a neutral, straight ahead position, as determined by a sensor in a mechanical linkage of the steering control.

Abstract: A swather tractor has a pair of driven ground wheels at one end where a header is supported and a pair of steerable wheels at the other end for supporting the tractor. The driven ground wheels are hydraulically driven so that an operator controlled steering control is arranged to control a differential in rate of supply of hydraulic fluid to control a relative speed of rotation of the driven wheels and thus a turning direction of the tractor. The steerable wheels have a steering system that is operable in response to the steering control to positively steer the steerable wheels and there is provided an arrangement to deactivate the steering system at large turns so that the steerable wheels are free to castor.

Abstract: A stand on mower includes a left foot pedal and a right foot pedal. Each foot pedal is spaced from the other and is dimensioned to support one of the operator's feet. Each foot pedal is biased to a neutral position generally parallel to a horizontal surface of a foot platform located generally between or behind a pair of traction drive wheels. The left foot pedal and the right foot pedal pivot independently forwardly and rearwardly to forward and reverse traction drive positions, and are connected to a pair of wheel motors respectively that rotate each of the traction drive wheels in either forward or reverse based on the traction drive positions of the foot pedals.

Abstract: An integrated steering control system includes a primary, automatic and rear control valves. A steering wheel operates the primary steering control valve and is of a type which includes a leakage characteristic. Steering wheel movement is sensed and a signal is sent which results in the automatic steering control valve being operated for adding fluid that supplied to a steering cylinder by the primary steering control valve in order to compensate for leakage, the amount of added fluid being a function of vehicle ground speed. An electric actuator with position feedback is used for ground speed control. Whenever the actuator position shows that the ground speed is set to zero and a switch in the hydro-handle slot shows that the handle is in the Park position, the automatic steering control valve is activated to move the steering cylinder to a neutral, straight ahead position, as determined by a sensor in a mechanical linkage of the steering control.

Abstract: Provided an electrically-operated hydraulic actuator unit that includes an electrically-operated motor controlled by a control apparatus and actuating a volume adjusting mechanism through driving-side and driven-side arms, and a clutch mechanism in which the driven-side arm presses a contact member against a clutch case so that the driven-side arm is locked when a force from the volume adjusting mechanism is applied to the driven-side arm. The control apparatus can set duties of first to fourth drive signals to be output to the electrically-operated motor in a neutral-side start period, a neutral-side ordinary actuation period, a higher-volume-side start period and a higher-volume-side ordinary actuation period. The duties of the first and fourth drive signals are larger than that of the second drive signal, the duty of the third drive signal is larger than that of the fourth drive signal, and an integrated ON-time of the third drive signal is larger than that of the first drive signal.

Abstract: A patient support apparatus includes a frame, a plurality of casters coupled to the frame, and a wheel supported with respect to the frame and movable between a lowered position engaging a floor and a raised position spaced from the floor. The patient support apparatus also has a drive assembly with a first mode of operation coupled to the wheel and operable to drive the wheel to propel the patient support apparatus along the floor and a second mode of operation decoupled from the wheel so that the wheel is free to rotate when the wheel is in the lowered position and the patient support apparatus is moved along the floor. A first user input is provided to move the wheel between the raised and lowered positions and a second user input is provided to signal the drive assembly to drive the wheel.

Abstract: A steering system for tracked vehicles having two brake circuits which is activated after a failure of the primary steering mechanism. The steering system includes a steering switch (L) that can be controlled by a steering axle which, in the event of primary steering system failure, acts upon the brakes of the vehicle in such a manner that rotation of the steering axle results in a braking action upon a track on the inside of a curve.

Abstract: A hydraulic steering device for vehicles, especially construction machines, with which is simple and robust mechanically and can be precisely controlled, without possessing the disadvantages of the current state of the art. A hydraulic swivelling motor for producing the steering motion, which is connected to a variable flow rate pump with reversal of its direction of delivery.

Abstract: A hydraulic transaxle comprises: a housing having a fluid sump therein, the housing including mutually joined housing parts; a pair of first wheels disposed at one of front and rear portions of the vehicle; an axle disposed in the housing; a center section disposed in the housing, the center section being formed therein with a pair of fluid ducts; a hydraulic pump disposed in the housing, fitted to the center section, and communicating with the fluid ducts; and a hydraulic motor disposed in the housing, fitted to the center section, and communicating with the fluid ducts so as to be fluidly connected to the hydraulic pump. The hydraulic motor includes a cylindrical motor shaft relatively rotatably and coaxially penetrated by the axle and drivingly connected to the axle.

Abstract: An all-terrain fire fighting apparatus has a high power-to-weight ratio, a hydraulic skid steer drive system, a drive-by-wire control system, a proportionally joystick controlled nozzle turret, and a 1500 psi foam injecting water supply system which supplies the nozzle turret and a high-pressure hose mounted on a reel. To dissipate heat load from the fire fighting apparatus systems, the fire fighting apparatus cooling system employs a cooling shroud in the form of a box with multiple system radiators stacked on one face of the box and the remaining faces containing exhaust fans mounted to draw air out of the box and through the stacked heat exchangers. The fire fighting apparatus is capable of being operated remotely by means of onboard GPS, real-time imaging, and inputs to the joystick controller and fire fighting apparatus drive-by-wire system.

Abstract: A hydraulic traction system for vehicles is described. The system comprises a hydraulic vane motor mounted at each wheel of the vehicle, and equal number of identical hydraulic vane motors operated as engine driven pumps, and a control system for regulating the flow and direction of hydraulic oil during operation. The hydraulic motor is of a novel design that has a hollow non-drive shaft that accepts incoming hydraulic oil, this allows internal components of the hydraulic motor to be arranged in such a way to improve the efficiency of the hydraulic traction system.

Abstract: A method and system are described for calibrating speed controls for a vehicle having a pair of drive means on opposite sides of the vehicle driven by independent speed controls and where relative speed of the drive means is used to direct the vehicle. In one aspect, angular motion of the vehicle is detected using at least one of a gyroscopic angular sensor and a pair of accelerometers to determine a rate of yaw; a speed control output for controlling the relative speed is adjusted so that the rate of yaw is lower than a threshold when speed control inputs for controlling the relative speed are equal; and one or more speed control adjustment parameters are determined and stored for use during operation for controlling the relative speed of the drive means. A microcontroller may be used to receive sensor outputs (e.g. from the gyroscope and/or accelerometers) and speed control inputs and to determine the speed control adjustment.

Abstract: A method of controlling the speed of a right front wheel and a left front wheel on a work machine includes receiving a speed command based at least partially on an operator input and monitoring at least one wheel steering angle of at least one front wheel. A first front wheel speed command may be determined based at least partially on the at least one wheel steering angle. In addition, a second front wheel speed command may be determined based at least partially on the at least one wheel steering angle. The first front wheel speed command and the second front wheel speed command may be output to independently control the speed of the right and the left front wheels.

Abstract: A hydraulic system includes first and second pumps, first and second motors, and three valves for selectively creating combined and basic hydraulic flow. The arrangement of valves permits combined flow to be provided to both motors in series to cause high speed operation of the motors, and permits combined flow to be provided to one motor and basic flow to the other motor. When applied to a vehicle, the arrangement provides a steerable high speed series arrangement of the vehicle's drive motors.

Abstract: The present invention provides a method and apparatus for brake steering a tracked vehicle such as, for example, a military tank. More precisely, the present invention provides independent control of a left brake and a right brake to create a track speed differential and thereby turn the vehicle. The apparatus of the present invention preferably includes a controller, a plurality of circuit selector actuators operatively connected to the controller, and a plurality of brake apply actuators operatively connected to the controller. A plurality of valves are disposed in fluid communication with the plurality of circuit selector actuators. The left brake is in fluid communication with one of the plurality of brake apply actuators, and the right brake is in fluid communication with another of the plurality of brake apply actuators.

Abstract: The present invention relates to a zero turning radius vehicle having at least one steerable front wheel and a multistage steering input system separately capable of steering the at least one front wheel and selectively driving the drive wheels. A front wheel steering system comprises at least one oblongated sprocket meshingly connected to a steering shaft. An engagement cam system provides the ability to selectively, independently couple the steering wheel to pump arms driving a first and second drive wheel. A steering cam shaft comprises at least one steering cam that acts on at least one bearing. Once the engagement cam system rotates the at least one bearing into place to receive the at least one steering cam, rotation of the steering cam independently alters the speed of one drive wheel in relation to the other drive wheel in response to steering input provided by the operator.

Abstract: A pump system includes a housing, an input shaft, a pump shaft; a hydraulic pump body, a PTO shaft, a power transmission gear train, and a PTO clutch mechanism. The housing has a narrow gear accommodating space surrounding a region including a mesh point between the first and second transmission gears of the power transmission gear train, a PTO clutch accommodating space which surrounds the PTO clutch mechanism and which is fluidly communicated with the gear accommodating space, and a pair of first and second suction/discharge ports which communicate the internal space of the housing with an outside of the housing. The first suction/discharge port is arranged within the gear accommodating space so as to be positioned in an opposite side to the PTO clutch accommodating space with the mesh point between the first and second transmission gears interposed therebetween.

Abstract: A differential steering assist system is provided for an off road utility vehicle with a pair of steerable front wheels and at least one pair of driven left and right rear wheels. The system uses a steering position sensor and wheel speed sensors that sense the wheel speed of the driven left and right rear wheels. An electronic control unit provides speed reducing commands to the left or right rear wheels based on the sensed steering position and sensed wheel speed.

Abstract: An hybrid four wheel drive system characterized by a vehicle having a conventional rear wheel driveline as well as a conventional driving front steer axle powered by an hydraulic motor. The hybrid four wheel drive system is provided in multiple embodiments, particularly with and without an hydraulic pressure accumulator.

Abstract: The present invention relates to a tubular valve tower extension element (30) for connection to a free end of a valve tower (22) of a vehicle's steering system. The connection end (42) of the valve tower extension element (30) can be connected to a valve tower (22) and comprises a bearing (32) located opposite the connection end (42) in the region of an opening (34) defined by one end of the extension element (see FIG. 1).

Abstract: A compact crawler type tractor having an excellent turning feeling is provided. A hydraulic speed change mechanism for turning includes a hydrostatic transmission pump for turning and a hydrostatic transmission motor for turning, and is characterized in that the hydrostatic transmission pump for turning is a variable displacement pump, and an output of the hydrostatic transmission motor for turning is input into a differential mechanism. By combining the hydrostatic transmission pump for turning and the hydrostatic transmission motor for turning and the differential mechanism, an excellent turning feeling can be obtained.

Abstract: A hydraulic transaxle comprises: a housing having a fluid sump therein, the housing including mutually joined housing parts; a pair of first wheels disposed at one of front and rear portions of the vehicle; an axle disposed in the housing; a center section disposed in the housing, the center section being formed therein with a pair of fluid ducts; a hydraulic pump disposed in the housing, fitted to the center section, and communicating with the fluid ducts; and a hydraulic motor disposed in the housing, fitted to the center section, and communicating with the fluid ducts so as to be fluidly connected to the hydraulic pump. The hydraulic motor includes a cylindrical motor shaft relatively rotatably and coaxially penetrated by the axle and drivingly connected to the axle.

Abstract: A device for stabilizing traction in a zero turn mower having a riding frame, a pair of front caster-type wheels, a primary right-side rear wheel and a primary left-side rear wheel, and an asymmetric drive system to said rear wheels for driving and steering, comprising: a) auxiliary right-side and left-side rear wheels rotatably mounted on stub axles positioned rearwardly of said primary rear wheels; b) a first rigid member extending between and pivotally coupled to said auxiliary right-side rear wheel and said primary right-side rear wheel; c) a second rigid member extending between and pivotally coupled to said auxiliary left-side rear wheel and said primary left-side rear wheel; d) a first drive coupling member for driving said auxiliary right-side rear wheel in tandem with said primary right-side rear wheel; and e) a second drive coupling member for driving said auxiliary left-side rear wheel in tandem with said primary left-side rear wheel.

Abstract: A steering transaxle comprises: left and right drive shafts drivingly connected to respective steerable wheels; a differential gear unit differentially connecting the drive shafts to each other; a transaxle casing having an opening, the transaxle casing incorporating the differential gear unit and the drive shafts; a cover for covering the opening of the transaxle casing; a variable hydraulic motor having a movable swash plate, the hydraulic motor being provided on the inside of the cover; a motor control mechanism for controlling the movable swash plate, the motor control mechanism being provided on the outside of the cover; and a hydraulic oil port for oil supply and delivery to and from the hydraulic motor, the hydraulic oil port being provided on the outside of the cover.

Abstract: A vehicle including an integral transaxle apparatus with axles, a driving hydrostatic transmission (HST), a steering HST, and a differential unit. Driving operating means for slanting operation of a first movable swash plate of the variable displacement driving hydraulic pump for switching the travelling direction between forward and backward and for changing the travelling speed, and steering operating means for slanting operation of a second movable swash plate of the variable displacement steering hydraulic pump so as to determine the leftward and rightward cornering angle are provided. The steering hydraulic motor has a third movable swash plate interlocking with the driving operating means so that the slanting direction of the third movable swash plate is changed according to the operation of the driving operating means, whereby the vehicle turns laterally in the same direction in response to the steering operating means whether the vehicle travels forward or backward.

Abstract: A vehicular hydraulic system having a hydraulic pump, a first hydraulic application and a second hydraulic application arranged in series. A relief valve is arranged parallel with the second application to allow fluid to bypass the second application when fluid pressure upstream of the second application exceeds a threshold value. The first and second applications may be a brake assist device and a steering gear assist device. The hydraulic system may also include a priority valve for diverting a portion of the fluid flow to the second application when the pressure upstream of the first application exceeds a threshold value. The threshold value for the first application may be greater than the threshold value for the second application. The hydraulic system may include a pump having a discharge rate that falls within a predefined range. A check valve may also be arranged parallel with the relief valve and second application.

Abstract: A vehicular hydraulic system having a hydraulic pump, a first hydraulic application, a second hydraulic application and a hydraulic reservoir arranged in series. A check valve is positioned to allow the flow of fluid from a point between the second hydraulic application and the pump to a point upstream of the second hydraulic application when the fluid flow upstream of the second application has been significantly reduced. The first and second applications may be a hydraulic brake assist device and a steering gear assist device. The use of such a check valve may also be employed with a hydraulic system having a priority valve for diverting a portion of the fluid flow to the second application when the pressure upstream of the first application is elevated above a threshold value. The hydraulic system may also employ a pump that has a discharge rate that falls within a predefined range.

Abstract: A hydraulic traction system for vehicles is described. The system comprises a hydraulic vane motor mounted at each wheel of the vehicle, and equal number of identical hydraulic vane motors operated as engine driven pumps, and a control system for regulating the flow and direction of hydraulic oil during operation. The hydraulic motor is of a novel design that has a hollow non-drive shaft that accepts incoming hydraulic oil, this allows internal components of the hydraulic motor to be arranged in such a way to improve the efficiency of the hydraulic traction system.

Abstract: A vehicle comprises a vehicle frame, a prime mover mounted on the vehicle frame, a laterally turnable wheel disposed at one side of the vehicle frame, a pair of drive wheels disposed at the other side of the vehicle frame, a steering operation device, a traveling operation device for setting the traveling speed and direction of the vehicle, and a pair of transmissions for controlling the rotary speed and direction of the respective drive wheels. The transmissions are operationally connected with the steering operation device so as to create a difference of rotary speed between the drive wheels according to operation of the steering operation device. The transmissions are operationally connected with the traveling operation device so as to drive the drive wheels in a common rotary direction from their stationary state according to operation of the traveling operation device.

Abstract: A method of controlling the speed of a right front wheel and a left front wheel on a work machine includes receiving a speed command based at least partially on an operator input and monitoring at least one wheel steering angle of at least one front wheel. A first front wheel speed command may be determined based at least partially on the at least one wheel steering angle. In addition, a second front wheel speed command may be determined based at least partially on the at least one wheel steering angle. The first front wheel speed command and the second front wheel speed command may be output to independently control the speed of the right and the left front wheels.

Abstract: There is provided a working vehicle having first and second hydraulic pump units operatively driven by a driving source and arranged away to each other in a width direction of the vehicle. In the working vehicle, each of the first and second hydraulic pump units includes a pump body; a port block formed with an oil passage for supplying/discharging an operating fluid to/from said pump body; a pump case connected to the port block so as to define a pump body accommodating space for surrounding the pump body; and a pump shaft for rotatably driving the pump body, the pump shaft having an input end operatively connected to said driving source. A drain port for opening the pump body accommodating space outward and a charge suction port for drawing in an oil from an oil tank in order to supply a charge oil to a hydraulic circuit fluidly connecting with the corresponding hydraulic motor unit are provided respectively in first and second assemblies formed by the corresponding pump case and port block.

Abstract: A patient support apparatus has a lower frame and an upper supported above the lower frame and movable relative to the lower frame. A plurality of casters are coupled to the lower frame. A wheel is movable relative to the lower frame between a lowered position engaging the floor and a raised position spaced from the floor. A drive assembly is coupled to the wheel and is operable to drive the wheel to propel the patient support apparatus along the floor. A foot pedal is coupled to the lower frame and is movable to raise and lower the wheel relative to the floor. Elevation adjust pedals are coupled to the lower frame and are movable to change an elevation of the upper frame relative to the lower frame.

Abstract: A fluid driven differential, having a fluid filled housing, an input shaft, and a pair of output shafts. The input shaft is attached to an automobile driveshaft outside of the housing and to a propeller inside the housing. The output shafts are each attached to an axle and wheel outside the housing and to a turbine inside the housing. When the driveshaft rotates the input shaft, the propeller generates a fluid current that turns the turbines and thereby turns the output shafts, the axles, and the wheels. A pair of return conduits direct fluid from the vicinity of the turbines to the vicinity of the propeller.

Abstract: A skid steer vehicle has a steering controller that monitors the speeds of the left and right wheels and steers those wheels in directions that are calculated to reduce, eliminate or minimize wheel skidding with respect to the ground while the vehicle is turning.

Abstract: A work vehicle with a hydrostatic steering system is disclosed which is capable of performing optimum control of the absorption torque of a hydraulic pump according to running load; capable of preferentially ensuring turning performance and implement speed when running load is relatively low; and capable of ensuring desired turning performance even when running load is relatively high. To this end, a bulldozer with a hydrostatic steering system, wherein the power of a hydraulic motor driven by pressure oil fed from a hydraulic pump operated by an engine is transmitted to right and left crawler tracks through a differential steering means composed of planetary gear trains etc., is designed to control the absorption torque of the hydraulic pump according to the speed ratio of a torque converter calculated by a speed ratio operation unit.

Abstract: The present invention relates to a zero turning radius vehicle having at least one steerable front wheel and a multistage steering input system separately capable of steering the at least one front wheel and selectively driving the drive wheels. A front wheel steering system comprises at least one oblongated sprocket meshingly connected to a steering shaft. An engagement cam system provides the ability to selectively, independently couple the steering wheel to pump arms driving a first and second drive wheel. A steering cam shaft comprises at least one steering cam that acts on at least one bearing. Once the engagement cam system rotates the at least one bearing into place to receive the at least one steering cam, rotation of the steering cam independently alters the speed of one drive wheel in relation to the other drive wheel in response to steering input provided by the operator.