Abstract: An apparatus for controllably moving a work implement. The implement is connected to a work machine and is moveable in response to the operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick that generates an operator command signal, which is indicative of a desired velocity of the work implement movement. Cylinder position sensors produce cylinder position signals in response to the position of lift and tilt cylinders. A valve assembly receives an electrical valve signal, and controllably provides hydraulic fluid flow to the respective hydraulic cylinders to move the cylinders in accordance with the operator command signal. A controller receives the operator command and cylinder position signals, and responsively produces a pump command signal to change the displacement of a variable displacement pump to regulate the movement of the hydraulic cylinders.

Abstract: A variable displacement pump has a discharge passage and a displacement controller disposed to decrease pump displacement in response to an increasing pressure signal and to increase pump displacement in response to a decreasing pressure signal. A load sensing pump control for the pump includes a displacement control valve having an input port connected to the discharge passage and a signal port connected to the displacement controller. A valve spool controls communication between the input and signal ports and is biased in a direction to block the inlet port from the signal port by a spring. The spool has a differential area for exerting a force against the spool in opposition to the spring force proportional to the pump discharge pressure entering the valve through the input port. A variable force can be selectively exerted against the spool in opposition to the spring force to change the displacement of the pump.

Abstract: An apparatus for controllably moving an implement is provided. The implement is connected to a work machine and is movable between first and second implement positions in response to operation of a hydraulic actuator. The apparatus includes a joystick with first and second positions and a neutral position. The joystick is normally biased in a neutral position and is movable between the first and second positions. The apparatus senses the position of the joystick and responsively generates a joystick position signal. The joystick maintained at the first and second detent positions in response to manual movement of the joystick to the respective first and second detent positions. The joystick is released from the detent position in response to receiving a release detent signal. The apparatus senses the position of the work implement with respect to the work machine. The apparatus provides hydraulic fluid flow to the hydraulic actuator in response to a magnitude of an electrical valve signal.

Abstract: An apparatus for controllably moving a work implement is disclosed. The implement is connected to a work machine and is moveable in response to operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick. A joystick position sensor senses the position of the joystick and responsively generates an operator command signal. An implement position sensor senses the position of the work implement and responsively produces an implement position signal. A microprocessor based controller receives the implement position and operator command signals, modifies the operator command signal, and produces an electrical valve signal in response to the modified operator command signal. An electrohydraulic valve receives the electrical valve signal, and controllably provides hydraulic fluid flow to the hydraulic cylinder in response to a magnitude of the electrical valve signal.

Abstract: A method for controlling an apparatus (100) for controllably moving an implement (102) is provided. The implement (102) is connected to a work machine (104) and is movable between first and second implement positions in response to operation of a hydraulic actuator (106). The apparatus (100) includes a joystick (306) with first and second positions and a neutral position. The joystick (306) is normally biased in a neutral position and is movable between the first and second positions. The apparatus senses the position of the joystick (306) and responsively generates a joystick position signal. The joystick (306) maintained at the first and second detent positions in response to manual movement of the joystick to the respective first and second detent positions. The joystick (306) is released from the detent position in response to receiving a release detent signal. The apparatus (100) senses the position of the work implement (102) with respect to the work machine (104).

Abstract: A method for controllably moving an implement is provided. The implement is connected to a work machine and is movable between first and second implement positions in response to operation of a hydraulic actuator. The method includes a joystick with first and second positions and a neutral position. The joystick is normally biased in a neutral position and is movable between the first and second positions. The method senses the position of the joystick and responsively generates a joystick position signals The joystick maintained at the first and second detent positions in response to manual movement of the joystick to the respective first and second detent positions. The joystick is released from the detent position in response to receiving a release detent signal. The method senses the position of the work implement with respect to the work machine. The method provides hydraulic fluid flow to the hydraulic actuator in response to a magnitude of an electrical valve signal.

Abstract: Vehicles having implements are typically used to perform repetitive functions in work cycles. An implement control system raises and lowers an implement relative to the vehicle and reduces the stresses applied to the vehicle from abruptly stopping the motion of the implement. A lever pilot signal is produced in response to the pivotal position of a control lever. An electrohydraulic pilot signal is also produced. The pilot signal having the greater pressure is directed to a main valve for controlling the position of the implement. The method and apparatus of the instant invention are applicable to a number of vehicles having a hydraulically operated implement.

Abstract: A pump control assembly (16) controls the displacement of a pump (11) and provides a standby pressure (87) that is greater than the difference (96) between the load pressure and the pump discharge pressure. A valve mechanism (38) provides a predetermined pressure signal to a valve member (23) for adding a force to the valve member to provide a control signal to an actuating member (17) which adjusts the pump's flow and pressure to a standby condition. The pump control assembly provides a more precise control of the standby position while eliminating large, bulky springs.

Abstract: It is common practice to provide the servo-system for a variable displacement pump with a "load-plus" valve to maintain pump discharge pressure above a minimum pressure level and above a load pressure in a fluid actuator connected to the pump in response to the load pressure in the actuator. Systems of this type are normally lacking in a device for ensuring that the prime mover for the pump functions at maximum efficiency. This invention is directed to a pressure and horsepower limiting valve (24) for ensuring such efficiency by modulating a load pressure signal (P.sub.L) communicated to the "load-plus" valve (23).

Abstract: Apparatus for reducing the noise made by circulation of an endless drive chain comprising a plurality of substantially identical links about a drive sprocket and idler is disclosed. According to the invention, a substantial portion of the energy present in pivotal movement of adjacent links with respect to each other, which occurs as the links are received on the drive sprocket and idler, is absorbed and returned to the pivotal movement therebetween which occurs when the links leave their engagement with the drive sprocket and idler. Specific embodiments of the invention particularly suited for use in reducing track noise in a track-type vehicle are described.

Abstract: A speed control system for an internal combustion engine having a variable speed throttle includes an operator input control member connected through suitable linkage to vary the setting of the variable speed governor and includes a balance mechanism having spring means operating in opposition to the reactive forces of the governor for providing a relatively uniform control feel over the range of the operator control member.

Abstract: A steering arrangement for construction vehicles and the like comprises a steering column assembly pivotally mounted on a stationary support for selective adjustment about a pivot axis disposed transversely relative to such assembly. A steering handle, rotatably mounted on the assembly, is operatively connected to a steering valve by linkage means for selectively steering a vehicle in response to rotation of the steering handle. The linkage means includes a push-pull cable having its upper end pivotally mounted about a pivot axis coincident with the pivot axis about which the steering column assembly is pivotally mounted on the stationary support to prevent actuation of the steering valve upon adjustment of the steering column assembly.