US 5,014,596 AGranted

Remote control modification for manually controlled hydraulic systems

OwnerLouis G. St. Martininventor

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Abstract

A remote control modification (11) for a hydraulic steering system (13) of the type used to steer underground loaders and the like is disclosed. The remote control modification comprises a bidirectional, spring-loaded remote control valve (51) connected in parallel with the bidirectional, spring-loaded control valve (19) that normally responds to steering inputs created by the manual movement of a steering arm (25). The remote control valve (51) has outlet ports (75 and 77) that are smaller than the outlet ports (39 and 41) of the manual control valve (19). Movement of the piston of the remote control valve (51) is controlled by a slave hydraulic actuator (53). The flow of hydraulic fluid to the slave hydraulic actuator (53) is controlled by a solenoid-actuated valve (59). The solenoid (61) of the solenoid-operated valve (59), in turn, is controlled by a receiver (63) that responds to radio frequency control signals (105) generated by a remotely located transmitter (65). Located in the hydraulic lines between the solenoid-operated valve (59) and the slave hydraulic actuator (53) are restrictor/reverse bypass pressure relief valve combinations (55 and 57). Finally, preferably, the hydraulic line running to the larger capacity chamber of the slave hydraulic actuator (53), i.e., the non-shaft chamber, is coupled to the hydraulic return tank via a relief line that contains a manually adjustable restrictor valve (67).

A hydraulic control system including a manual control valve having input and output ports for controlling the application of hydraulic pressure to one or more hydraulic actuators, the improvement comprising:

a remote control modification, said remote control modification including:
(a) a remote control valve having input and output ports connected in parallel with the input and output ports of said manual control valve, the output ports of said remote control valve being smaller in size than the output ports of said manual control valve;
and,
(b) an electro-hydraulic control system for controlling the operation of said remote control valve, said electro-hydraulic remote control system comprising:
(i) a slave hydraulic actuator including:
(1) a piston moved shaft coupled to said remote control valve for controlling the position of said remote control valve;
and (2) chambers located on opposite sides of said piston such that said shaft passes through one of said chambers but not the other chamber;
(ii) a three-position electrically actuated valve for controlling the flow of hydraulic fluid to said slave hydraulic actuator, said electrically actuated valve coupled to said slave hydraulic actuator such that:
(1) hydraulic pressure is applied to the non-shaft chambers of said slave hydraulic actuator when said electrically actuated valve is in a first position;
(2) hydraulic pressure is applied to the shaft chamber of said slave hydraulic actuator when said electrically actuated valve is in a second position;
and (3) the shaft and non-shaft chambers of said slave hydraulic actuator are both connected to a hydraulic fluid reservoir when said electrically actuated valve is in said third position;
(iii) a receiver coupled to said electrically actuated valve for energizing said electrically actuated valve so as to position said electrically actuated valve in one of said first and second positions upon receipt of a suitable remotely generated radio frequency signal;
and,
(iv) a remote transmitter for generating radio frequency signals suitable for causing said receiver to energize said electrically actuated valve so as to position said electrically actuated valve in one of said first and second positions.

11 more elements

Abstract

Claims19