Patent GB-168122-A (GB)
Title: Improvements in or relating to railway station train indicator mechanism and the like
IPC: B61L25/00
Filed: 1920-05-17
Abstract: 168,122. Waller, P. H. May 17, 1920. Order apparatus.-Relates to electric signalling systems suitable for operating a railway-station train indicator, in which a display board providing for selective display of a series of signs is controlled from a distant position. The system comprises a master member which can be moved by a single movement to any point, a follower which moves up to the master member in steps, and distant step-by-step mechanism which is energized to move synchronously with the follower. The master member 21, Fig. 4, is mounted loosely on a shaft 23 and can be moved so that a pointer on it is opposite any indication on a setting-plate 20 by means of a handle 22. The follower 24, 25 is fixed to the shaft 23, and carries a second pointer. On the master member is a conducting ring 28 and on the follower a conducting ring 32, whilst an insulating strip 31 and a stud 30 are opposite the respective pointers. The rings 28, 30 are supplied with current by means of brushes 29, 33. When the master member has been moved, the stud 30 rests on the conducting ring 28 and current passes to energize a coil 41. The follower is turned through one step by a pawl 35 on the core 37 of the solenoid, which is retained at the limit of its movement by a catch 54 engaging a tooth 56. A conducting strip 42 is attached to the core 37 of the solenoid and against the strip press brushes 43, 44. The current passes from the coil 41 through the brushes 43, 44 to contacts 46, 47, Fig. 6, on the distant step-by-step mechanism, which contacts are closed when the coil of this mechanism is not energized, and to the common return lead 48. The core 37 in its upward movement closes two contacts 50, 51 so that current passes round the coil 49 and moves the core of the distant step-by-step mechanism. This mechanism may be that described in Specification 156,331. As soon as the coil 49 is energized, contacts 46, 47 are separated but two other contacts 57, 58 are - closed so that current passes round the coil 60 of an electromagnet, to the core of which catch 54 is attached. The movement of the core. releases the tooth 56 and the core 37 can move the follower 24 another step. These movements continue until the stud 30 moves on to the insulating- - strip 31 when the pointers on the master and follower members are together. Each changeable - sign on the display board has a step-by-step mechanism, and to each is allocated a master and follower and repeating mechanism as described. One common return lead 48 is used and three wires for each controlling-member and step-bystep mechanism operated thereby. Before any of the movements can be carried out a switch 39 must be closed, and this is opened when all the movements have been completed by an electromagnet 63. For this purpose a ring 67 on the master member 21 is connected to a stud 69 and a ring 71 on the follower 25 is connected to a stud 70 These studs are only in contact in the zero position. When each follower has reached its zero position, current passes through a brush 66 to ring 67, through a brush 72 from ring 71, through contacts 96, 97, Fig. 4, in each control mechanism and through the coil 63. If a large number of signs have to be operated, the first -control mechanism is used to operate a selector switch arm 73, which carries three pairs of contacts. The switch over which it moves has three rings 74, 75, 76 and three series of contact studs 77, 78, 79. These studs are arranged in radial sets of three, and the arm 73 connects each of the three in any one set to one of the rings. Each radial set of studs is connected to the contact 46, contact 57 and one end of the coil 49 respectively of a step-by-step mechanism. The rings 74, 75, 76 are connected to the three points of a switch S at the transmitting end, through which they can be connected to any one of a series of three points V, W, X, Y, Z, each of which is connected to a control mechanism. The number of wires between the two ends of the system is thus reduced to seven. Specifications 17434/97, 16083/05, 9676/08 and 132,265 are referred to.