Allis-chalmers Corporation

Charles P Heisig

John R Plate

A safety device for a power takeoff shaft whereby the hydraulic control valve spool for controlling the power takeoff drive operates a switch in the engine starter circuit to disable the starter circuit when the power takeoff clutch is engaged.

Safety start switch and power takeoff control valve arrangement

A load sensitive hydraulic system for operating auxiliary equipment on a vehicle with a priority flow control valve to provide priority pressure in operating a regenerative steering circuit of the hydraulic system. The regenerative hydraulic steering circuit provides load sensing and utilizes single source of pressurized fluid which responds to various loads in the hydraulic system. A priority valve assures that the steering demands are met before providing adequate pressure for all other auxiliary functions.

Load sensitive hydraulic system

A control valve operated by the steering wheel to selectively connect a variable displacement pump for operating a hydraulic cylinder in each of two directions to steer the vehicle. The hydrostatic system is regenerative in steering of the hydraulic cylinder in one direction since both sides of the hydraulic cylinder are connected to the high pressure input line in steering in one direction. A pilot line is connected to the valve output to sense load pressure and feed back to the compensator of the variable displacement pump to vary the displacement in response to load demands of the hydrostatic system.

Growing community of inventors

Milwaukee, WI, United States of America

Charles P Heisig