Patent GB-192114-A (GB)
Title: Improvements in and connected with signalling apparatus for mines
IPC: B66B19/06
Filed: 1921-09-21
Abstract: 192,114. Graham, A., and Paton, A. Sept. 21, 1921. Mechanical telegraphs; mine and colliery signals.-In a mechanical telegraph for mines, a travelling pointer is moved to a position indicating the number of strokes given to a bell, and is then restored, actuating one of a set of stationary pointers during the return movement. The transmitting hand-lever is so constructed that it must be pulled an equal distance at each stroke. Resetting is effected by the motion of the winding engine. Transmitter. The lever 1, Fig. 6, is pivoted at a point 2 eccentric with respect to a quadrant 4 which is pivoted at 30 and is held up by a spring 7. If the lever 1 be pulled through a short stroke, it cannot be returned on account of the notches 31 engaging a pawl 9 on the lever. If, however, it be pulled through a full stroke, it depresses the quadrant 4 (on account of the eccentricity of its pivot) and causes a notch 11 on the pivoted arm 5 to engage a pin 10 on the quadrant, so that the latter is held down. The lever 1 can then be returned to the starting position, whereupon the heel 12 trips the arm 5 and the quadrant 4 springs back to the position shown. Receiver. The received impulses are stored in a chain-wheel J on a shaft M, which is rotated step-by-step when a ratchet wheel L is operated by a pawl T' on a draw-bar T, Fig. 1 (side elevation). The bar T is pulled upwards by each impulse, lowering the pawl 16 through link-work 17, 18, so as to limit each movement of the shaft M to one step in conjunction with a toothed wheel K carried thereby. During its upward movement, the shaft T drops the re-setting rod G to its inoperative position by lifting the lever G<3> until its end G<4> disengages from the rod G. The rod T also lifts the piston S<1> of a dash-pot S, and on falling strikes the bell X<2> with a hammer X<1>. When the group of impulses is complete, the piston S' falls and its tappet R depresses one end of a lever Q<1>, the other end of which thereupon trips the retaining-pawl Q and so permits the shaft M to return to its starting position, under the influence of a weight O on the chain H, which passes over the chain wheel J. The chain H carries a block E, Fig. 5<a>, (front elevation), which projects through a slot in the face A of the indicator, and bears a crosspiece or travelling pointer E<1>. During the descent of the chain under the influence of the received impulses, the cross-piece E<1> passes under springs F, Fig. 4, arrranged on each side of the chain, the edges C' of the bell-cranks C being bevelled to allow it to pass. When, however, the chain ascends on the release of the retaining-pawl Q, the cross-piece E<1> trips that one of the ball-cranks C which is immediately above it, and then passes out in front of the springs F leaving the bell-crank C in question in position as a pointer to indicate the signal, the resetting rod G being at this time in its dropped or inoperative position as described above. A plurality of successive signals can be recorded the belt-cranks C all remaining in the operated position until they are all reset together. Resetting device. Resetting is effected by the movement of the winding engine, which raises the rod G and causes the pins thereon to turn back the pointers C to the inoperative position. The mechanism for raising the resetting rod G comprises a lever W, Fig. 8, pivoted at W<1> and connected to the rod G bv wire or levers at its end W<3>. At the other end is a wheel W<2> which is eccentrically pivoted at W<8> and weighted so that its longest radius is normally uppermost. The wheel is retained in this position by engagement of its notch W<6> with the upper end of a stirrup W<4> , but when the rod G, Fig. 1, falls, on receipt of a signal, the end W<3> of the lever is raised and the wheel W<2> is lowered on to a rotatable part U of the winding engine, the stirrup W<4> being thereby lifted out of engagement with the notch W<6>. When the engine starts the part U revolves and turns the wheel W<2>, the lever W being thereby turned counterclockwise owing to the eccentricity of the wheel. The resetting rod G is thereby raised. If the signal " stop " (1 bell) is given during the running of the engine. the rod G is immediately reset, locking the bell-crank pointers C in their inoperative positions. However, the travelling pointer E<1> is locked at position I by the topmost lever C, and serves to record the signal.