Patent GB-330530-A (GB)
Title: Improvements in railway signalling apparatus
IPC: B61L5/22
Filed: 1929-03-08
Abstract: 330,530. Stewart, A. C. March 8, 1929. Detonating signals; detonator apparatus; lamp signals; pyrotechnic signals.-In detonator signalling apparatus of the kind in which a detonator is placed on the track rail by a slidable arm operated in conjunction with the ordinary signal, in addition to the detonator placed on the rail a pyrotechnic flare or cartridge is provided, fired by a striking pin actuated by a train-operated hammer or trigger. The charge of the cartridge may be adapted to detonate, or give a flash of any desired colour. As described, the device is actuated by depression of the track rail, Specification 331,929 being referred to. A pair of detonators 10 is carried by a sliding arm 11 moving between guides 13 and normally advanced to hold the detonators on the rail 12 (when the ordinary signal is at danger) by an arm 21 pivoted at 22 and having pin-and-slot connection 23 with arm 11, arm 21 being operated by one arm 25 of a lever, the other arm 16 of which is biassed by spring or, as shown, by a weight. Arm 16 is extended and connected by a cable 17 with the ordinary signal operating mechanism (not shown). Arm 11 carries a pyrotechnic cartridge &c. holder 29 which is preferably hingedly mounted at 42<a> and provided with a suitable catch (not shown). The holder is preferably obliquely mounted as shown to direct the flash away from the track and upwards. A striking pin 30 is adapted to fire the cartridge. A flexible plate 35 carried by arm 11 has a shoulder 34 adapted to engage a projection 33 on a hammer 31 pivoted on a fixed arm 32 and loaded by a spring 36 or counterweight, so that when the detonators are placed on the rail, shoulder 34 moves the hammer 31 to put the spring 36 in compression, the end 35<a> of the plate comes into position under the head 12a of the track rail, and the striking pin 30 comes into position over the hammer. Depression of the rail, and with it plate 35, releases the hammer 31. A recess 38 may be provided in the sleeper 15 under the chair 39 to facilitate depression of the rail. Alternatively, the lubricant casing 20 and detonator mechanism, instead of being mounted on the sleeper, may be mounted on a frame fixed in the railroad bed and straddling the sleeper. In a modification, the cartridge is fired by a lever pivoted on arm 11, one end of the lever operating the striking pin and the other end being positioned under the head 12a of the rail 12 when the detonators are in position. Instead of a single holder 29, a number of cartridges may be mounted in recesses in a revolving barrel rotated step-by-step by hand or suitable mechanism. Alongside each detonator 10 fired by the train wheels there may be provided a pyrotechnic flare or a more powerful detonator in one with, or so close as to be fired by, the smaller detonator, and the larger detonator may incorporate a coloured flare. A mirror or system of mirrors may be fixed on the cab to reflect the flash of the flare into the cab or other means may be used to transmit the audible and visible signals to the driver. The arm 11 may be connected to a carrier with red and green lenses or transparent discs one or other of which is brought into position in front of a stationary lamp according to the advanced or retracted position of the arm.