Patent GB-251767-A (GB)
Title: Improvements in means for automatically stopping trains
IPC: B61L3/02
Filed: 1925-05-04
Abstract: 251,767. Jones, O. C. May 4, 1925. Track apparatus actuating signals on, and for stopping, trains.-A vertically sliding rod b with a spring-buffer shoe a carried by the train and raised by a fixed insulated ramp a<1> on the track, executes an idle stroke or operates a plunger to pierce a hole in a metal strip sealing the brake pipe according to whether a swith l, connected to the ramp and operated in conjunction with the usual signals, is closed or open. An opening c in the brake-pipe or a branch thereof is normally sealed by a metal or other strip i guided in grooves h and bearing against suitable packing. A plunger f adapted, when raised, to perforate the strip and cause application of the brakes carries a pivoted depending member e of magnetic material normally held in the path of the upper end d of rod b by a spring e<1>. When the usual signal associated with a ramp is at danger, the switch l is open, and under these conditions the rod b when raised by the ramp engages the member e and operates plunger f to apply the brakes. If the signal is at clear, switch l is closed, and contact of the shoes with the ramp closes a circuit from a train-carried battery g<1> through an electromagnet g which attracts member e to the left, Fig. 2, moving it out of the path of the rod end d. The rod b is thus raised without effecting operation of the plunger f. A bell &c. l<1> may be provided to signal to the driver that a clear " track signal is being passed. A second plunger f<1>, longer than and operated in conjunction with plunger f, may be provided to cooperate with a hole c<1> and pierce a small hole in the strip i to effect a partial application of the brakes and sound a whistle p. The train-carried apparatus may be used with ramps of three different heights which respectively sound the signal bell l<1> at predetermined points of the track without raising rod b far enough to pierce the strip i, raise rod b to a height which renders plunger f<l> alone effective at an adverse track signal, or raise rod b to render plunger f effective at a danger signal. The strip i is drawn from a supply drum on to a drum j<1> provided with hand-operated ratchet mechanism k, by which, after a brake application, a fresh portion of strip may be moved into position to seal the holes c, c<1> and reset the device. The downward movements of the plunger f and rod b are aided by springs f<2>, q, and to ensure positive withdrawal of the plunger after piercing the strip a rod r may be provided along which a perforated projection on rod b slides freely in upward movement, a head r' on rod r being engaged by the projection in the downward movements. A brake application occurs also in the event of a fault in the electric circuit. According to the Provisional Specification the rod b may operate an audible signal bv rack-and-pinion gearing, and the movement of the rod may operate a trigger to release a spring, or may operate a valve admitting air to one side of a piston, the spring or piston serving to give a sudden rotary impulse to the armature of a magneto to supply the requisite electrical energy.