Abstract: An engine-driven pump supplies pressurized hydraulic fluid to vehicle brake and steering circuits. A ground driven variable displacement pump controlled by a control circuit is de-stroked when the engine-driven pump is operational. The variable displacement pump includes a movable piston which divides a bore into a pilot chamber and a pump chamber. An outlet line with a check valve communicates fluid one way from the pump chamber to the vehicle circuits. An inlet line with a check valve communicates fluid one way from a reservoir to the pump chamber. A ground-driven rotatable cam member reciprocates the piston. A spring urges the piston towards the cam member and towards a full stroke position. A pilot line which communicates fluid pressure from an outlet of the engine-driven pump to the pilot chamber. When the engine-driven pump is operational the pressure in the pilot line moves the piston away from the cam member, thus de-stroking the variable displacement pump.

Abstract: A microprocessor-based control system includes an automatic calibration and configuration feature. A calibration and configuration algorithm operates to establish the sensor ranges of all sensors installed and disables certain configurable features if the associated sensors are not present. The algorithm also provides a functional test of the control system during the calibration process.

Abstract: A microprocessor-based control system includes an automatic calibration and configuration feature. A calibration and configuration algorithm operates to establish the sensor ranges of all sensors installed and disables certain configurable features if the associated sensors are not present. The algorithm also provides a functional test of the control system during the calibration process.

Abstract: A pilot operated control valve includes a spool type pilot valve member which is coupled to the main valve member by a pair of springs so that both pilot pressure forces and spring forces act on the main valve member. The main valve member and the housing in which it moves enclose a damping chamber. A damping orifice extends through the main valve member and connects the damping chamber with a pilot pressure chamber to reduce vibration of the main valve member.

Abstract: A differential lock control system includes a solenoid valve which operates hydraulic differential lock mechanisms in response to the operation of a control circuit. The control circuit includes normally closed, steering-responsive switches which open to unlock the differential when steering effort exceeds a certain level. The steering-responsive switches are operated by pins which are exposed to pilot pressures on either end of a valve spool of a conventional pilot-operated steering valve.

Abstract: A solenoid includes a coil, a pole assembly, an armature movable in the pole assembly and an air gap separating the armature from part of the pole assembly. A single mumetal washer may be fixed to the armature adjacent the air gap or a pair of mumetal washers may be fixed to the armature and to one of the pole parts on opposite sides of the air gap.

Abstract: A compactor device for large round bales is disclosed comprising a horizontally disposed cylindrical housing containing a plunger, a double toggle mechanism connected to the plunger, a hydraulic cylinder connected to the double toggle mechanism for driving the plunger, and a stabilizer linkage connected to the plunger and the double toggle mechanism for maintaining the plunger in a vertical position during compaction of a bale.