Priority steer system--hydraulic

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Turning now to the drawing, a hydraulic system for an electric-powered vehicle comprises a suitable source of hydraulic fluid comprising a pump 10 which draws fluid from a tank or reservoir 11 and supplies it by a main supply line or conduit 12 to a hydraulic system including an implement circuit indicated generally at 13 and a vehicle steering circuit indicated generally at l4.
The pump 10 is driven by a suitable electric motor 15 which is preferably separate from the vehicle propulsion motor but which may be generally run from the same batteries.
This system is for an electric-powered vehicle wherein the source of electric power is storage batteries or the like and it is necessary to conserve energy as much as possible.
Power for the motor 15 is supplied by a suitable electric power source such as a battery 16 connected by suitable conductor means 17 within a circuit for supplying electric power to the motor 15.
The circuit includes a first switch means 18 operated by a priority and pressure sensing valve system to be described, and a second switch 19 operated by the implement system valves for completing the circuit for conducting electrical power from the battery 16 by way of a conductor 20 to the motor 15.
The pump 10 supplies pressurized fluid along conduit 12 to a priority valve and pressure sensing group 21 comprising a first valve 22 which is pressure-responsive and is operative in a normal position to direct fluid along a passage or conduit 23 to an accumulator 24 for accumulating and storing a quantity of pressurized fluid sufficient to operate a steering system for a significant number of times or cycles.
This valve 22 functions to isolate steering system pressure from implement working pressure when the pressure exceeds 1300 psi.
A conduit 25, including a restriction 26, communicates with conduit 23 and to a steering valve 27.
The steering valve 27 is operative in a position as shown, which is a neutral position to block the fluid flow along conduit 25 and is operative in either one of two positions to either side of the neutral position to direct fluid to either side of the double-acting hydraulic motor 28 for steering the vehicle