GB191320334A - Improvements in and relating to Overwind and Overspeed Preventing Gear for Colliery Winding and like Engines. - Google Patents

Abstract

20,334. Lochhead, W. Sept. 9. Overwinding, preventing; emergency power cut-off gear.-Mechanism for preventing overwinding and overspeeding of winding-engines comprises a traveller or depth-indicator carrying a governor-adjusted slide adapted to engage a curved series of stops, and thereby to close the throttle valve, to centre the reversing-lever, and to release a weighted brake lever; and means are provided for applying pressure to the brake lever in the event of overwinding. The depthindicating cross-head 10, traversed along horizontal guides 11 by a screw 21 driven from the winding-engine, carries with it a slide 13 which is adjusted transversely to the screw by a governor acting through links 3, 4, rack 5, pinion 6, and eccentric rod 15. The rod 15 is mounted at each end on a short shaft 9, to one of which the pinion 6 is secured, and one end of the slide 13 is formed as a strap enclosing the rod 15. The free end 17 of the slide 13 coacts with a series of stops 18 of varying height formed on bars 19, 19<a>, which, on the occurrence of excessive speed, are moved sideways, thereby raising a tripping-arm 29 and causing the throttle to be closed, the valve gear to be thrown into neutral position, and a retarding-brake to be applied. The bars 19, 19<a>, which may be coupled by a link 20, are carried on legs 32, 33, the inner pair 32 being supported on bell-cranks 30 connected to the trip arm 29, and the outer pair 33 coupled to weighted levers 34 which tend to return the bars to the position shown. For each end of the wind, there is arranged a stepped plate 36 and an adjustable screw 36<a>, which, when moved sideways by engagement with the slide 13, actuate by rods 39 a plate 38, thereby raising the catch 29 as before. At the same time, a second tripping-catch is released, which causes pressure to be applied to the brake lever to arrest the engine.