Patent GB-191111282-A (GB)
Title: Improvements in or connected with the Prevention of "Overwindings" in Mines.
Inventor: DAGLISH HARRY BOLTON
IPC: B66B5/08
Filed: 1911-05-10
Granted: 1912-05-10
Abstract: 11,282. Daglish, H. B., and Beck, W. S. May 10. Overwinding, preventing; emergency power cut - off gear. - Relates to mechanism for preventing overwinding and excessive speed, and comprises means for giving a regulated movement to the rod actuating the stopgear according to the speed at which the engine is running near the end of the wind, means for actuating the stop-gear first gradually and then fully if the speed is too high at any part of the wind, and an end stop for preventing the cage from passing the level. A screw shaft 1 driven from the winding-engine carries two tappet nuts 12 with rollers 13 adapted to engage towards the end of the wind with wiper levers 14 pivoted on pins 15 and coupled at their inner ends by a link 17 to a swinging arm 20. The outer end of this arm has an inclined serrated face 21 adapted to engage a tooth 22 connected by a link 26 and bell-crank lever 27 to a sliding rod 28 controlling the brake and throttle. The position of the tooth 22 is adjusted through a linkage 23, 24 by a governor driven by a sprocket chain 8. If the speed is properly reduced towards the end of the wind, the tooth 21 is withdrawn by the governor as the inclined face 21 is lifted, so that the automatic brake and throttle control is not brought into action. The amount of movement of the control rod 28 depends on the point at which the tooth 22 engages the inclined face 21, that is, on the degree by which the engine speed exceeds that allowable for the position of the cage. The rod 28 is locked against reverse movement by a pawl 30, which may. be lifted by a handle 32. To ensure stoppage when the cage reaches the level, the tappets 12 engage stops 51 on the rod 16, which carries a pin 46 engaging the depending arm of a three-armed lever 44. A stirrup link 48 with slotted arms engages the ends of the lever 44 and is connected by an arm 49 to a rock-shaft 36. This shaft carries a detent normally supporting a weighted lever pivoted on the shaft 38 which is connected by an arm 40 and a slotted link 41 to the control rod 28. An end movement of the rod 16 therefore trips the weighted lever and causes a sudden application of the brake and closing of the throttle. In order to prevent the speed from exceeding the allowable maximum at any part of the wind, the governor linkage is connected by a slotted rod 56, Fig. 5, to a bell-crank lever 57 which is adapted to raise the threaded portion 67 of a loose ring 59 into engagement with a rotating screw 60. The end movement of the rod 58 caused by this engagement is transmitted by a slotted rod 62 either direct to the lower arm of the bell-crank lever 27 or through an intermediate lever 63, according to the direction of motion. In either case the brake and throttle control rod 28 is actuated. If this does not reduce the speed sufficiently, an arm 70 connected with the bell crank 27 engages an arm 71 on the rock-shaft 36 and so trips the weighted lever previously referred to. The mechanism is enclosed in casing 50, and an indicator is driven through a worm shaft 9.