초록 ▼

A hydraulically-actuated controller is disclosed for controlling delivery of hydraulic fluid from a variable-displacement, pressure-compensated pump to a hydraulically-powered reel on which is wound a cable or other flexible member extending from the reel to a tie point. Rotation of the reel is cont

A hydraulically-actuated controller is disclosed for controlling delivery of hydraulic fluid from a variable-displacement, pressure-compensated pump to a hydraulically-powered reel on which is wound a cable or other flexible member extending from the reel to a tie point. Rotation of the reel is controlled appropriately to maintain the cable tautly between the reel and tie point as the distance therebetween changes. One use is on an electrically-powered mining vehicle, the power cable of which extends from a fixed power source to the vehicle-mounted reel. The controller is in a pay-in-mode whenever the distance between the reel and tie point is decreasing or remaining constant, and in a pay-out mode whenever said distance is increasing. During pay-in, pressurized hydraulic fluid is directed from the pump to the reel motor. During pay-out, pump output is occluded and fluid is directed through a restriction from the reel motor to the reservoir, the restriction serving to brake motor rotation. Two of four valves in the controller are hydraulically piloted in each position and biased in the pay-in position. A separate check valve ensures that pressure at the pilots is about equal during pay-in but unequal, favoring the pay-out position, when the reel is paying out cable.

대표청구항 ▼

A hydraulic controller for use with a reel used for windably storing a flexible cable extending from the reel to a tie point to which a distal terminus of the cable is affixed, the reel paying out a required length of the cable whenever the distance between the reel and said tie point is increasing,

A hydraulic controller for use with a reel used for windably storing a flexible cable extending from the reel to a tie point to which a distal terminus of the cable is affixed, the reel paying out a required length of the cable whenever the distance between the reel and said tie point is increasing, maintaining the unwound cable extending from the reel to the tie point in a taut condition when said distance is remaining constant, and paying in the cable when said distance is decreasing, the reel powered by a hydraulic motor hydraulically coupled to a source of pressurized hydraulic fluid, the controller comprising: a first port hydraulically coupled to the source of pressurized hydraulic fluid, a second port hydraulically coupled to the motor, and a third port hydraulically coupled to a reservoir of hydraulic fluid; a hydraulic pressure-actuated valving means for valving the flow of hydraulic fluid from the first port to the second port and from the second port to the third port, the valving means assuming a pay-in mode when the distance between the reel and the tie point is either decreasing or remaining constant, and a pay-out mode when said distance is increasing; (a) in which pay-in which the valving means passing pressurized hydraulic fluid from the first port to the second port to drive the hydraulic motor to urge the reel to rotate in a pay-in direction; and (b) in which pay-out mode the valving means occluding passage of hydraulic fluid from the first port through the valving means to the second port and passing a partially restricted flow of pressurized hydraulic fluid from the second port to the third port so as to hydraulically brake rotation of the motor when the reel is rotating in a pay-out direction; the valving means comprises a first, a second, a third, and a fourth valve, the first, second, third, and four valves hydraulically intercoupled, wherein; (a) the first valve is a two-position valve having an inlet port, an outlet port, and an exhaust port, the inlet port coupled to the first port of the valving means; (b) the second valve is a two-position valve having an inlet port coupled to the second port of the valving means and an outlet port coupled to both the outlet port of the first valve and the second port of the valving means; (c) the third valve is an adjustable pressure-relieving pressure-control valve having an inlet port coupled to the exhaust port of the first valve and an outlet port coupled to the third port of the valving means; and (d) the fourth valve is a check valve having an inlet port coupled to the outlet port of the second valve and an outlet port coupled to the second port of the valving means.