Patent GB-163736-A (GB)
Title: Improvements in or relating to mine signalling apparatus
IPC: B66B19/06
Filed: 1919-12-01
Abstract: 163,736. Houghton, H., and Chadburn's (Ship) Telegraph Co., Ltd. Dec. 1, 1919. Mine and colliery signals.-In a mine signalling system, mechanical telegraphs o, l, Fig. 1, are located at various points in the mine and are connected by metal rods or tubes a, b and gearing p, q so that on the operation of any one of the instruments or of a separate transmitting instrument n the pointers of all will move. A second pointer on the engine room instrument is carried forward by the telegraph pointer and remains in position until returned to zero by the engine. One anti-clockwise turn of the handle of the transmitter o returns all the telegraph pointers to zero. The means nf operating the engine room instrument is shown in Fig. 14 and the means for returning the second pointer to zero is shown in side elevation and plan in Figs. 7 and 8. The shaft 41* is turned in an anti-clockwise direction by a clockwise rotation of the handle of a transmitter. The telegraph pointer 4 is mounted on a sleeve 3 which is turned one step for every anti-clockwise rotation of the shaft 41* by a spring pawl 42* and a ratchet-wheel 43. To prevent the sleeve 3 from moving too far, a locking-wheel 45 is held by a spring lever which is lifted by a cam 46 just in front of pawl 42*. A zero arm 53 and zero stop 54 are provided and to prevent overwinding there is a tooth missing on wheel 43. The pointer 4 is returned to zero by one clockwise rotation of shaft 41* by a friction clutch 44 turned by a rotation of a loose sleeve 50 through spur sheels 48, 49. A ratchet mounted on shaft 41* is within the spur wheel 48 so that it can only be turned in the one direction. The second pointer 11 on the shaft 8 is carried forward by pointer 4 by means of pins 1, 5 mounted respectively on a flange 2 on the sleeve 3, and on a flange 6 on a clutch-piece 6a slidably mounted on shaft 8. On rotation of pointer 11 and shaft 8 an arm 10 moves aside a lever 19 by striking a spring pawl 25. This lever projects through a slide member 20 and moves it against a spring 24. A projection 16a on a bar 16 pivoted at 17 normally rests on the member 20 but when the latter moves this projection 16a comes over a slot 26 and the bar 16 falls and locks slide 20 in position. A pointed lever 28 attached to the bar 16 falls into the path of pins 30 on a wheel 29. A pawl 15 attached to the bar 16 engages a ratchet-wheel attached to the shaft 8 and holds it. A spring pawl 31 on the bar 16 moves past a lever 33 mounted on a spindle 32. After an order has been given, pointer 4 is returned to zero by turning the transmitter handle in the opposite direction but pointer 1 remains locked until released by the engine. The shaft 40 on which the wheel 29 is mounted is connected with the winding engine so that when the engine is started one of the pins 30 on wheel 29 raises the lever 28 and thus the bar 16. The projection 16<a> moves out of the slot 26 and the slide member 20 returns to normal position, allowing shaft 8 and pointer 11 to be returned to zero by spring 13. The spring pawl 31 as it rises moves the lever 33 and an arm 34 thereof disengages the clutch 6<a> against a spring 12. As the clutch moves back a notch 37 on a lever 36 falls over a projection on the arm 34 holding out the clutch until a projection thereon lifts the lever 36 as the clutch is pressed in again by spring 12. According to the Provisional Specification, the engine pointer is carried forward by the telegraph pointer by means of a pin on the latter projecting into a recess on the former.