Abstract: A vehicle height adjust control apparatus that increases the durability or service life of a fluid system, including a fluid supply-discharge device and a fluid actuator, can have a pressure sensor and vehicle height sensors. If a microcomputer determines that the pressure detected by the pressure sensor is greater than a predetermined pressure, the microcomputer changes a target vehicle height to a vehicle height presently detected by the vehicle height sensors. In a preferred construction, the target vehicle height is changed to the vehicle height presently detected, if it is determined that the detected pressure remains greater than the predetermined pressure for at least a predetermined length of time. The predetermined length of time is changed to a longer time when the fluid temperature is relatively low. These additional determination conditions prevent unnecessary or ineffective changes of the target vehicle height due to by a sensor abnormality or a fluid temperature change.

Abstract: A self-levelling apparatus for a seat comprises a base (21, 22, 27), a seat levelling assembly (2, 18, 19, 41) displaceably connected with the base, and a reversible electrical motor (40) disposed between the seat and the base for rotation of the seat levelling assembly around an axis about parallel with the base. The seat levelling assembly is disposed between the base and the axis. Themotor shaft (42) extends parallel with the axis and engages with a flexible actuation means, such as a roller chain, fixed at its one end at the base. The apparatus also comprises a positional detection means for control of the motor. The apparatus further comprises arcuate co-operating seat and base bearing elements (2; 22) of which at least one has a surface defined by rotation of a straight, curved or irregular line around the axis, such as a cylinder or cone segment surface.

Abstract: A vehicle suspension control includes a vehicle body control responsive to body/wheel velocity at the corners of the vehicle body to derive a demand force command for dampers at each corner of the vehicle body for vehicle body control and applies each of the derived demand force commands to its respective damper only when a comparison of the direction of the demand force command with the sensed relative velocity of the damper indicates that a force corresponding to the demand force command can be effectively exerted by the damper. But the suspension control also includes a vehicle stability control responsive to an indicated vehicle lateral acceleration in a turn to determine, independently of the vehicle body control, a stability compression damping command for the suspension dampers on the side of the vehicle opposite the direction of the lateral acceleration and a stability rebound damping command for the suspension dampers on the side of the vehicle in the direction of the lateral acceleration.

Abstract: A sugar cane harvester for harvesting two rows of cane stalks is equipped with a pair of endless track assemblies which each include a track frame suspended from the main frame of the harvester by a four-point suspension including tilt and elevation cylinders that permit side-to-side tilting, and elevation adjustments of the harvester main frame so as to place base cutters at the best attitude for cutting cane contained in the rows, even if the rows are at different elevations.

Abstract: A vehicle height adjust control apparatus and method precisely performs vehicle height adjustment while preventing unnecessary vehicle height adjustment. In the apparatus, a microcomputer compares the amount of shift of a vehicle height detected by a vehicle height sensor with a first predetermined value. If the amount of shift is greater than the first predetermined value, the microcomputer integrates the amount of shift. The integral of the amount of shift is compared with a second predetermined value. If the integral is greater than the second predetermined value, the microcomputer determines that vehicle height adjustment should be started. The first and/or second predetermined values used in an initial period immediately after an engine is started are smaller than the first and/or second predetermined values used after the initial period.

Abstract: A retractable cargo height sensing system is provided for use with a cargo transporting vehicle to sense the height above a roadway of cargo carried by the cargo transporting vehicle. The height sensing system includes an alarm for signaling when the cargo is above a predetermined height above the roadway. The system also includes a plurality of sensors mounted on the cargo transporting vehicle and movable between a lowered position and a raised position. In the raised position, the sensors are positioned to detect when the cargo is above the predetermined height and provide a signal to the alarm to activate the alarm or alternatively send a signal to the alarm to de-activate the alarm when the cargo is below the predetermined height. In a lowered position, the sensors are positioned below the predetermined height to facilitate movement of the cargo transporting vehicle.

Abstract: A swing-to-tree feller buncher has its boom swing-house assembly adjustably supported from its track carriage frame by a leveling mechanism which includes a front link, a rear link, and a pair of laterally spaced apart hydraulic cylinders. Both links are fixed to the frame toward the front of the carriage and the front link is shorter than the rear link. The upper ends of the hydraulic cylinders connect to the turntable support of the swing-house assembly at a position forward of the rear link and extend rearwardly to connect at their lower ends to the frame of the carriage at a position which is rearward of the rear link. The turntable support is also pivotable from side to side relative to the carriage about a minor axis.

Abstract: Disclosed is a method of adjusting a tractor to a horizontal position and an apparatus for performing the same. The method comprises the steps of determining whether or not the tractor is in an automatic mode, determining whether the tractor is in a flat land or in a slope land if the tractor is in the automatic mode, adjusting a height of the body with respect to a ground if the tractor is in the flat land, determining a driving direction of the tractor if the tractor is in the slope land, adjusting the body to the horizontal position by controlling the body in left and right directions thereof if the tractor is driving in a contour direction, adjusting the body to the horizontal position by controlling the body in front and rear directions thereof if the tractor is driving in a latitudinal direction, and adjusting the body to the horizontal position by controlling the body in front, rear, left and right directions thereof if the tractor is driving in an oblique direction.

Abstract: A timber harvesting machine including a chassis supported by endless tracks. A platform is mounted on the chassis. A platform is rotatable on the turntable in an annular bearing race on the turntable. A boom is mounted on the platform and includes a main boom mounting pin which is pivoted on one side of the axis of rotation of the platform. A boom actuating cylinder has a mounting pin which is mounted on the other side of the axis of rotation and directly over the annular bearing race regardless of the rotational position of said platform relative to said turntable.

Abstract: A vehicle body level control system which includes three variants for optimization of a level control system during loading and unloading operations. These three variants can be employed independently of one another or in any combination. In a first variant of the invention, the control delay time is extended during loading and unloading operations. In a second variant of the invention, the control dead band is extended during loading and unloading operations. A third variant of the invention consists in performing, in the adjustable state of operation, the control to the presettable level only when the vehicle body level does not vary or varies only very little.

Abstract: A dynamic seat leveling device for a riding lawnmower or tractor has a virtual rotational point located below the leveling device itself. When operated on hilly terrain, such an arrangement accomplishes three objectives: 1) the operator remains level; 2) the operator's center of gravity remains centered directly above a critical balance point which is at ground level, midway between the right and left wheels; and 3) the operator remains at a constant elevation. Keeping the operator at a constant elevation, as the leveling device shifts from one side to the other, minimizes the power that would otherwise be needed to repeatedly raise and lower the operator as the tractor tilts from left to right. Minimizing the power required allows the use of a compact leveling drive that fits between the seat and frame of the tractor.

Abstract: Wheel suspension system for a vehicle having a frame and a wheel oriented in a longitudinal direction of the vehicle. The system includes an axle beam coupled to the frame of the vehicle and a traction motor coupled to the wheel for rotating the wheel. The traction motor is pivotally coupled to the axle beam such that the wheel is tiltable in a direction transverse to the longitudinal direction of the vehicle. To this end, an intermediate support is connected to the axle beam by a first suspension pin and to the traction motor by a second suspension pin whereby the first suspension pin is substantially parallel to the second suspension pin.

Abstract: A device for indicating the level of the axle of a vehicle having a reference mark indicator which follows the level of the vehicle axle is arranged fixedly connected on the axle of the vehicle and changes its position as a result of the change in level. An electric signal which corresponds to the level of the axle is obtained from a resistance network which is firmly attached to the body of the vehicle. In a level indicator which operates with little wear, is economical to manufacture, and nevertheless is of high accuracy, the resistance network has, associated with it, a contact structure which, under the action of a magnet device which is movable by the change in position of the reference mark indicator, can be deflected in the manner that an electrical connection which is dependent on the level of the axle is produced.

Abstract: A slope working machinery which moves and travels safely on the slope has a suspension device having at least one of a winch and a driving device attached to a body thereof, has a work stand to work on the working machine capable of keeping nearly horizontally and to use to carry bagagges, whereby working on a steep slope can be conducted with much ease and safe.

Abstract: A vehicle (10) intended for operation on level ground is equipped with a chassis (22) and a wheel carrier (50) on which a wheel (12) is supported. In order to operate the vehicle (10) on an incline, a pivoting arrangement (44) is inserted between the wheel carrier (50) and the chassis (22). The pivoting arrangement comprises a mount (52), a pivot arm (54) mounted therein and an actuating arrangement (56) to move the pivot arm (54). The attachment points on the chassis (22) or on a support (46) spaced at a distance thereto and on the wheel carrier (50) are configured in such a way that the wheel carrier (50) can be directly attached to the chassis (22) or to the pivoting arrangement (44).

Abstract: A low aspect self-propelled vehicle (1) operated by a driver (4) sitting on top of it, has its seat (7) supported from beneath by a flange (12) which is pivoted to tilt about a horizontal axis (15) in the mid-vertical plane of the vehicle. The spacing between the axis (15) and the seat (7) is sufficient to ensure that when the seat is tilted about the axis by operation of a tilt control mechanism (21), the center of seat also displaces a significant extent in the uphill direction of the slope. This reduces the downhill movement of the center-of-gravity (10) of the combination of vehicle plus driver, so that the risk of the vehicle toppling is reduced.

Abstract: The invention pertains to electrically operated levelers and stabilizers for vehicles, particularly recreational vehicles, wherein a reversible electric motor extends and retracts telescoping members mounted to the vehicle by a linkage system. Operation of the linkage system through a linkage and slot arrangement automatically pivots the stabilizer to a horizontal storage position and lowers the stabilizer to an operative position during extension of the telescoping members. The links are locked by an over-center relationship when the stabilizer is extended, and automatically unlock from the over-center relationship when the stabilizer members are retracted and raised. A foot at the outer end of the stabilizer automatically pivots between storage and operative positions.

Abstract: A suspension control system for use with an automotive vehicle supported on front and rear road pairs of road wheels. Shock absorbers are provided between sprung and unsprung masses of the vehicle at the front and rear road wheel side tower positions for providing variable damping force characteristics. First behaviors of the vehicle at the front road wheel side tower positions are sensed. A predetermined transfer function is used to calculate second behaviors of the vehicle at the rear road wheel side tower positions based, on the sensed first vehicle behaviors. The damping force characteristics of the shock absorbers mounted at the front road wheel side tower positions are controlled based on the sensed first vehicle behaviors. The damping force characteristics of the shock absorbers mounted at the rear road wheel side tower positions are controlled based on the calculated second vehicle behaviors.

Abstract: A utility vehicle, such as a grape harvester (1), comprises a straddling frame (2), supported at its front and rear ends by double-acting hydraulic cylinders (17, 18 and 23, 24), which can be extended or retracted for levelling the frame (2). During horizontal or uphill travel, the rear cylinders (23, 24) are blocked for providing the vehicle (1) with a fixed rear axle (55), while the front cylinders (16, 17) are hydraulically interconnected in order to let them extend or retract in opposition to each other for providing the vehicle (1) with an oscillating front axle (56). During downhill travel the front cylinders (17, 18) are blocked for fixing said front axle (56) to the frame (2) and the rear cylinders (23, 24) are hydraulically interconnected for letting the rear axle (55) oscillate to the frame (2). The rear and front oscillation is controlled by an inclination sensor (91).

Abstract: A hydraulic jack includes three chambers (3, 4, 5), two of these three chambers being annular and enclosing a sliding cylindrical element (8) including a first piston (9) delimiting the two annular chambers (3, 4), and a second piston (10) delimiting the third, substantially cylindrical chamber (5) which is contiguous with one of the two annular chambers (3, 4). The hydraulic jack is used in hydropneumatic suspensions for automotive vehicles.

Abstract: An attitude control apparatus, for a vehicle having a body and a plurality of wheels, has an actuator operated by a fluid for expanding each suspension of the vehicle to control the stroke of each wheel. A first detecting device detects a variation of incline of the body of the vehicle when the body inclines from a horizontal position. A second detecting device detects the vertical position of each wheel relative to the body. A third detecting device detects the load applied to each wheel. A first control device controls the volume and direction of the fluid to be supplied to the actuator. A calculating device calculates the vertical displacement of each wheel, the current average height of the body, and the variation of the load on the wheel based on the variation of the inclined angle of the body, the vertical position of each wheel, and the load on each wheel. A setting device sets a target value for the average height.

Abstract: Dolly apparatus for hauling loads on a pitched surface includes frame structure secured to wheels, with the wheels being adjustable in height so that the dolly may be moved along a pitched surface with the load maintained in a proper horizontal orientation. Different embodiments are disclosed, which embodiments may be used for different types of loads. One embodiment is a relatively simple embodiment which may be used for a relatively light load, and a second embodiment is a relatively complicated embodiment which may be used to transport heavier loads. The second embodiment includes wheels which may be oriented ninety degrees for moving in two directions, for example for moving a load to a specific location in one direction and then moving it in a second direction for specifically positioning the load.

Abstract: A farm implement includes a plurality of equipment heads (such as planter heads) for engaging the earth and a carriage for mounting the heads for movement in a first direction. The equipment heads are kept level when moving in a first direction over terrain that is sloped and a second direction substantially perpendicular to the first direction so that the equipment heads remain in proper operative engagement with the earth. The leveling mechanism includes a channel shaped structure so that it is substantially stationary with respect to the carriage and extends substantially in a second direction, a movable ballast element mounted in the channel shaped structure, and a powered ballast moving device.

Abstract: A suspension control system for feedback-controlling the sprung mass acceleration signal y.sub.m and a method for introducing the unsprung mass acceleration signal y.sub.L into a tuning circuit to tune gain of an FIR filter. In this system, tuning is performed so as to cancel the road surface input y.sub.m close to a reference frequency (around 10-12 Hz). As a result, the sprung mass acts as a dynamic damper upon the road surface input y.sub.m close to the reference frequency (around 10-12 Hz), however, frequency bands other than the reference frequency band do not receive the contribution of the second term in the equation (6). That is, output from the tuning circuit to an adder becomes almost zero, and normal sky-hook control is performed. Though the sprung mass system acts as a dynamic damper, the unsprung mass system exceeds the sprung mass system in mass, and excessive resonance does not occur.

Abstract: A utility vehicle, such as a grape harvester (1) comprising a straddling frame (2), supported at its front and rear ends by double-acting hydraulic cylinders (17, 18 and 23, 24), which can be extended or retracted in order to level the frame (2). The rear cylinders (23, 24) are normally blocked for providing the vehicle (1) with a fixed rear axle (55), while the front cylinders (16, 17) are hydraulically interconnected in order to let them extend or retract in opposition to each other for providing the vehicle (1) with an articulated axle (56). The hydraulic cylinders (17, 18, 23, 24) are governed by two control valves (38, 39) which enable lifting, lowering and sideways levelling of the frame (2). During levelling operations, the hydraulic connection between the front cylinders (16, 17) is automatically broken by a control valve (65) in order to enhance the stability of the vehicle (1). This is particularly advantageous when the vehicle (1) is levelled during downhill travel.

Abstract: An apparatus and method for reduces the steering effort applied by a driver to a steering wheel of a vehicle to maintain straight line tracking of the vehicle. The apparatus includes an adjustable suspension unit interposed between a steerable road wheel and a chassis of the vehicle to adjust the chassis ride height. The apparatus further includes ride height sensors, an inclinometer, a steering effort sensor, and a processor for determining a desired ride height setting that will reduce the steering effort required to maintain the straight line tracking of the vehicle.

Abstract: A suspension control system for an automotive vehicle is provided. This suspension control system comprises variable damping force shock absorbers and a control unit which controls the shock absorbers to assume damping force characteristics in a range between preselected higher and lower damping coefficients. The control unit is operable to provide a control parameter indicative of bouncing motion of a vehicle body based on sprung vertical speed to determine a damping coefficient against the bouncing motion. When the control parameter is greater than a threshold value, the damping coefficient is modified to a lower value, while when the control parameter is less than the threshold value, the damping coefficient is modified to a higher value. With this damping coefficient modification, the bouncing motion is suppressed effectively while assuring passenger comfort.

Abstract: A vehicle has a real time suspension control which requires, as inputs, a set of absolute body modal velocity signals. Accurate estimates of these signals are derived from relative position sensors at the body suspension points by converting the relative vertical position signals from these sensors to relative body modal (e.g. heave, pitch and roll) velocity signals and passing each of these signals through a second order low pass filter including an additional phase inversion for compensation of the 180 degree filter phase lag. Thus, the necessity of absolute body accelerometers is eliminated, for a significant cost reduction. In a vehicle having significant front to rear flexing or flexing within the front or rear suspension that can affect the accuracy of the estimated absolute body roll velocity, the normal roll velocity transformation equation is modified to include only the front or the rear pair of relative velocity signals.

Abstract: The object of the inventional system is the so-called "modal" variant of the skyhook damping. The advantage of this variant over the local version is essentially constituted by enabling an individual damping of the eigenoscillation forms. Moreover, a definitive roll or sway moment distribution can be adjusted. For that purpose there are signals determined which represent the local vehicle body movements at selected points of the vehicle body. Basing on these signals, the heave, roll and pitch movements are inferred. These movements are differently weighted depending on travel maneuvers. By actuation of the damper systems dependent on the weighted heave, roll and pitch movements a specific influencing of certain components of the body movement is possible.

Abstract: An apparatus for controlling a suspension system disposed between a wheel and a body of an automotive vehicle, has a device for adjusting a response of the suspension system to mechanical excitations transmitted by the body and/or the wheels. A first controller is sensitive to a vertical speed and a vertical acceleration of the vehicle body, for developing a first virtual control signal of the adjusting device which is suitable for optimizing a ride of the vehicle. A second controller is sensitive to a deflection of the wheel and a vertical speed of the wheel relative to the ground, for developing a second virtual control signal of the adjusting device which is suitable for optimizing contact between the wheel and the ground. A supervising device is sensitive to the first and second virtual control signals for developing a real control signal which is applied to the adjusting device for adjusting the response of the suspension system as a function of a predetermined behavior strategy.

Abstract: A suspension system for utility vehicles of the type in which the chassis is supported at one end on an oscillating axle with a central pivot, has the oscillation of this axle controlled by one or two extensible links each in the form of a hydraulic cylinder unit. The second vehicle axle has limited oscillation used to shuttle the spool of a directional control valve which determines the flow of pressurized fluid for operation of the hydraulic cylinder units(s). The control valve can also be electrically operated responsive to the closing of switches responsive to the oscillations of the second axle.

Abstract: A suspension control device for a vehicle includes: a vehicle speed detector for detecting a vehicle running speed; a spring or damping rate variation calculator for calculating variation of an apparent spring or damping rate of a suspension of a vehicle due to increase or reduction of the vehicle running speed on the basis of the detected vehicle running speed; and a spring or damping rate variable correction device for varying and correcting the spring or damping rate of the vehicle suspension to a predetermined value on the basis of the variation of the spring or damping rate. The spring or damping rate is determined by the variation of the apparent spring constant which is proportional to variation in aerodynamic force due to displacement of the attitude of the vehicle, the apparent damping rate variation which is proportional to variation in aerodynamic force due to displacement velocity of the attitude of the vehicle.

Abstract: A vehicular suspension system comprises a hydraulic damper including a valve element having a plurality of positions and a pulse motor drivingly coupled with the valve element. A control unit is operatively coupled with the pulse motor. In order to avoid loss of synchronism of the pulse motor, the pulse motor is held stationary for a predetermined period of time after it has been determined that the pulse motor must reverse its direction of motion to reach a target position.

Abstract: Method and apparatus for maintaining vehicular ride height in a vehicle having a body, front and rear wheels and an air suspension including front and rear air springs. The method includes sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal. The method also includes processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator. The method further includes processing the vehicle speed signal to obtain a vehicle pitch offset signal, indicating vehicle body height change due to longitudinal vehicle acceleration. The method also includes adjusting the height of the vehicle toward a predetermined target ride height based on the vehicle height sensor signals which have been compensated for vehicle roll and pitch.

Abstract: A header adjusting system for a hillside combine harvester includes a master hydraulic cylinder assembly and a slave hydraulic cylinder assembly. The master hydraulic cylinder assembly is slaved to movement of the wheels relative to the combine frame. The slave hydraulic cylinder assembly is slaved to extension and retraction of the master hydraulic cylinder assembly. The slave hydraulic cylinder assembly causes the header to pivot about the longitudinal axis of the harvester in order to follow the contour of the ground. A header trimming mechanism is also provided to enable direct operator control of some of the pivoting action of the header about the longitudinal axis. A leveling system for a hillside combine harvester includes a cable and a biased, moveable reference pulley associated therewith.

Abstract: A drive train suspension system for a manure and compost treating vehicle wherein a linkage assembly is connected between the vehicle drive train assembly and the vehicle frame, on each side of the vehicle frame, so that the vehicle frame is articulately connected to a vehicle drive train assembly on each side. Fluid motors are connected between the vehicle frame and each drive train assembly so that the position of the vehicle frame relative to the drive train assembly can be selectively varied to thereby minimize potential damaging stress imparted to the drive train assembly by the lateral movement of the drive train relative to the vehicle frame, and to raise the vehicle frame to a selected elevation above the ground and/or maintain the vehicle frame substantially level.

Abstract: A suspension assembly for a vehicle such as a boom sprayer or the like having a first axle member with one end connected with a wheel and its opposite end pivotally connected with the vehicle chassis on the side of the chassis opposite such wheel, a second axle member having one end connected with a wheel and its opposite end pivotally connected with the vehicle chassis on the side of the chassis opposite such wheel and first and second air springs operatively positioned between a portion of the axle members and the chassis to cushion the chassis while traversing irregular and bumpy terrain.

Abstract: A walking truck including a platform pivotably supported above a base frame, inner racks and outer racks bilaterally disposed below the base frame and coupled by transmission shafts and cranks, a first motor drive controlled to move the inner racks and the outer racks alternatively for going upstairs or downstairs, a second motor drive controlled by a pendulum and two micro switches to move a balance linkage in either direction for keeping the platform in balance as the walking truck goes upstairs or downstairs.

Abstract: A four way tilt mechanism maintaining the superstructure of an off-road vehicle generally horizontal while the vehicle is working on uneven terrain is disclosed. The tilt mechanism is very robust and provides independent adjustment of the angle of tilt relative to each of two pivot axes. The tilt mechanism incorporates a spherical bearing mounted on a shaft perpendicular to the longitudinal pivot axis of the tilt mechanism to eliminate end-play in the joint which forms the longitudinal pivot axis. The longitudinal and transverse pivot axes lie in the same plane so that many of the the forces which are transferred from the superstructure of the vehicle through the tilt mechanism to the chassis of the vehicle cannot cause a torque on the components of the tilt mechanism.

Abstract: A suspension system for a vehicle has shock absorbers, each provided so as to be associated with one wheel and between sprung parts and unsprung parts, step motors, each being adapted for changing damping force characteristics of one of the shock absorbers by open loop control, and a controller for outputting control signals to the step motors. The controller is adapted for outputting control signals every predetermined time interval so as to make the damping force characteristics of the shock absorbers harder. According to the thus constituted suspension system for a vehicle, it is possible to prevent the driving stability from being lowered even when at least one of the step motors is thrown out of synchronism.

Abstract: The right and left front wheels of an asphalt finisher are each supported by a beam, one end of which is mounted to the body of the asphalt finisher by way of a pin such that the beam can swing, and the other end of the beam is mounted to the end of the piston rod of a hydraulic cylinder which is vertically mounted to the body of the asphalt finisher in a downward direction, both cylinders being connected to each other by way of a single oil line. As a result, when either one of the front wheels encounters an obstacle, the sideward inclination of the body can be eliminated.

Abstract: A vehicle body or chassis is raised and lowered on an associated suspension coil spring by a device including a screw, a motor and motor controller, and a gear drive. The device enables adjustment of body or chassis height by the vehicle operator while the vehicle is in motion. Locknuts determine a limited range of adjustment. A particularly advantageous application is adjustment of race cars for specific conditions pertaining to a particular race track or race event. In a preferred embodiment, major components of the device are readily removable from the vehicle, enabling the vehicle to be adjusted prior to a race, then modified to meet, illustratively, NASCAR rules operative during the race.

Abstract: The invention relates to an active suspension system for controlling the suspension of a wheeled land vehicle, which comprises an actuator (31) of variable length in parallel with a spring (34), connected between the body or chassis of a vehicle and a wheel and hub assembly (40) of such. The extension/contraction of the actuator is controlled by a control unit (60) in response to parameters measured by various sensors (61, 64, 65, 66 and 62). The control unit (60) also makes allowance for loads on the vehicle not measured by the sensors, so that accurate control of the suspension system is achieved.

Abstract: A vehicle height control apparatus for a vehicle is comprised of a fluid chamber installed for each wheel. The fluid chamber changes the vehicle height by receiving or discharging the fluid supplied from a fluid supply source. The vehicle height control apparatus operates to decrease the difference between right and left vehicle heights when the difference between the right and left vehicle heights is greater than a predetermined value, the vehicle is in a parked condition, and the fluid supply source cannot supply the fluid to the fluid chamber. The operation by the apparatus is carried out such that the right and left fluid chambers are communicated with each other.

Abstract: This self-propelled articulation-steered tractor has a positive adjustment system for controlling the orientation (both elevation and lateral tilt) of a transverse implement mounted on either the front or rear assembly of the tractor, and a reactive adjustment system for allowing terrain-responsive orientation of the axle of the other assembly (front or rear) not carrying the transverse implement. The positive adjustment system is operator controlled. The reactive system may comprise a mounting of the axle for the non-implement-carrying assembly so it freely pivots with respect to the frame of that assembly. An articulation joint transverse swivel pivot system is provided for lateral tilt movement between the front and rear assemblies of the articulation-steered tractor.

Abstract: A leveling system for a combine having a transaxle. The leveling system comprises a three point linkage coupling the transaxle to the supporting structure of the combine. The first and second links of the three point linkage are coupled to the underside of the transaxle. The third link is coupled to the top of the transaxle. A transverse sway bar is positioned between the supporting structure and the transaxle. Two hydraulic cylinders are mounted between the first and second links and the supporting structure for manipulating the angle of inclination of the transaxle relative to the supporting structure.

Abstract: A system for leveling a vehicle, such as a recreational vehicle, includes three extendable and retractable fluid-operated jacks. The jacks are spring-biased to their retracted position. Supply of hydraulic fluid under pressure extends the jacks, and the jacks are retracted by relieving the supply of hydraulic fluid pressure to the jacks to allow the springs to expel fluid from the jacks. A number of unique aspects are incorporated in the leveling system for providing highly advantageous construction, operation and installation.

Abstract: An active suspension system for an automotive vehicle is arranged to regulate the attitude of a vehicle body in a flat or balanced state by controlling hydraulic cylinders respectively disposed between a vehicle body and a road wheel, in response to an attitude change of the vehicle body. The active suspension system comprises electromagnetically operated variable vibration attenuation valves, each of which is fluidly connected with each hydraulic cylinder and is followed by an accumulator. Each variable vibration attenuation valve is adapted to be variable in its attenuation constant in response to a vertical acceleration experienced by the road wheel. The variable vibration attenuation valve takes on a low attenuation constant to maintain a high riding quality of the vehicle under a normal cruising condition, and a high attenuation constant to suppress the response of the road wheel under a rough road cruising condition.

Abstract: An automatic leveling system for a four-wheel vehicle system having outrigger assemblies at each of the four corners of the vehicle chassis and in which each outrigger assembly has an outrigger pad and a hydraulic cylinder for moving the pad downwardly and upwardly relative to the ground. The leveling system includes a low-pressure high-flow source of hydraulic fluid which is connected for one-way flow into the head ends of all four of the cylinders to lower all pads to the ground and then maintain them in contact with the ground. A level sensor senses the relative levelness of the right front and left rear corners of the vehicle and high-pressure low-flow hydraulic fluid is connected to the head end of the cylinder at the lower of those two corners to raise that corner of the vehicle relative to the ground.

Abstract: A system for automatically leveling a vehicle, such as a recreational vehicle installed with a plurality of extensible jacks and disposed at strategic positions on the vehicle underside, and responsive to an automatic level control electronics to extend simultaneously all of the jacks and at different speeds as determined by the angle of vehicle versus gravity and bring vehicle to a level condition. The jacks are stopped when they are use higher current than that used before the jacks contact the ground, to assure ground contact, and the vehicle is level.