GB448575A - Improvements relating to control apparatus for winding gear - Google Patents

Abstract

448,575. Brakes for winding-apparatus. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd., 1, Kingsway, London.-(Smith, D. M.; c/o Metropolitan-Vickers Electrical Export Co., Ltd., P.O. Box 3633, Johannesburg, South Africa) March 16, 1935, No. 8258. [Class 78 (v)] [See also Group XXXIV] Control equipment for fluid-operated brakes for winding-gear comprises a main brake control valve governed by a deceleration governor and means for changing over from this valve to an auxiliary control valve in an emergency, the auxiliary control valve being governed by a separate governor. The changeover valve 9 is connected with the cylinders of the main and emergency control valves 1, 7 by pipes 11, 22 respectively, and in the normal operating position the plunger 13 is held up against the pressure of the spring 14 by fluid pressure in the space 15 and puts the pipe 11 into communication with the pipe 12 leading to the brake engine. The space 15 is connected to the pressure conduit 5 through the trip valve 10, the plunger 16 of which normally is held up by a solenoid 18, but falls under the action of a weight 17 when the current through the solenoid is interrupted. In the latter position the pipe 19 leading from the space 15 is in communication with the exhaust pipe 21, and the plunger 13 falls, thereby putting the pipe 12 into communication with the pipe 22. The brakes are thus applied at a rate which is limited by the action of the deceleration governor 8. If the rate of deceleration is excessive, the governor 8 will raise the plunger 23 and the braking will be eased. The valve 1 may be of the kind described in Specification 392,252, and is provided with a manual or pedal control 2, an emergency trip 3, and an inertia governor 4. The valve 10 may be tripped either by an attendant, or by a secondary overspeed trip set for a higher speed limit than the primary overspeed trip. An interlocking arrangement may be provided to prevent resetting of the change-over valve until the pressure at the main control valve outlet corresponds with the pressure normally existing there when the brakes are applied.