Patent GB-314629-A (GB)
Title: Improvements in or relating to electrical signalling systems
IPC: B61D41/00
Filed: 1928-04-27
Abstract: 314,629. Siemens & General Electric Railway Signal Co., Ltd., and Castle, F. L. April 27, 1928. Selective signalling apparatus.-In a signalling system for indicating the various stopping places of one or more trains or the destination of lifts, the controlling apparatus for the system comprises tokens shaped in a manner characteristic of corresponding trains and adapted to be passed successively through a magazine in the order of departure of the trains to operate banks of contacts in the circuits of signalling lamps. Information regarding several trains may be signalled simultaneously. As shown in Fig. 1, the controlling apparatus is adapted to furnish information concerning three successive trains and comprises an upper magazine 4 which contains a pile of tokens 11, only one of which is shown, each of which comprises a flat plate, Fig. 8, having one side 16 slotted in such a mariner that the projections 18 correspond to the stopping places of the corresponding train. The tokens are threaded on to a rod 7 which extends downwardly into a lower magazine 5 and the arrangement is such that the tokens progressively fall through the upper magazine and are deposited in the lower magazine. Three rows of contacts 24<a>, 24<b>, 24<c> mounted on the side of the upper magazine correspond to three successive departures and the three lowest tokens co-operate with the rows of contacts to operate selectively the contacts opposite the projections 18 and corresponding to the stopping of the associated trains. Each row of contacts is associated with a vertical group of indicating lamps. A single projection 19 on each token controls a contact in circuit with a lamp for signalling the departure platform of the train. Located between the magazines 4, 5 is a drawer 30 which is adapted to transfer the last used token into the lower magazine. The drawer has a handle 32 and is normally retained against spring pressure in alignment with the upper magazine by an electromagnet 37 co-operating with an armature 35 on the drawer. When the train corresponding to the lowest active token leaves the station, the electromagnet 37 is de-energized to release the drawer and allow the token already therein to fall into the lower magazine. The attendant restores the drawer, which is again eleotomagnetically held, and thereby allows the token corresponding to the departed train to fall into the drawer and the other tokens to move down one place to permit transfer of the second and third departure indications to the first and second indicators respectively and the operation of the third indicator by a fresh token. The operation is repeated at each departure of a train. When all the tokens have fallen into the lower magazine the rod 7 may be withdrawn downwards through the magazine and reinserted through the upper magazine once more to transfer the tokens to the upper compartment in their correct sequence. The drawer carries an insulated stud 39 which controls a plurality of contacts (not shown) in such a manner that when the drawer is in alignment with the upper magazine the lamps circuits are closed, but when it is released an audible or visible signal is operated and the lamp circuits are opened. The tokens may be covered with a suitable insulating material, e.g. that known under the Registered Trade Mark " Bakelite." Each token may control the lamps of a plurality of indicators, the lamps being arranged either in parallel or series.