Patent GB-214861-A (GB)
Title: Improvements in or relating to automatic telephone systems
IPC: H04Q1/32
Filed: 1922-11-16
Abstract: 214,861. Lenaghan, T. Nov. 16,1922. Automatic exchange systems and apparatus. - A five-digit register consists of ten discs ID - - OD, Fig. 1, each carrying five pairs of contacts 85, 86 of which 85 is pivoted and 86 fixed. Each incoming digit energizes one out of ten magnets corresponding to the ten discs, for example a digit of six impulses would energize the magnet VI, and at the termination of the digit all the discs are rotated a fifth of a revolution so that a contact 85, 86 is closed on the disc corresponding to the energized magnet, the contact 85 being shifted as it passes the end of the attracted armature 95. Thus the number 73421 for example would be recorded by the closing of the first contact 85, 86 on the seventh disc, the second contact on the third disc, &c. The rotation of the discs at the end of each digit is effected by a magnet 78 which advances a rack 87 to which all the discs are geared. When a release magnet 25 is energized, the rack and discs are restored by a spring 92 and the deflected contacts 85 are restored by passing pivoted fingers Circuit arrangements. The operating magnets I - - O may be arranged as a relay counting chain, as shown in Fig. 2, successive relays being energized by the line impulses and each relay deenergizing its predecessor. The relays are divided into odd and even series which receive impulses over wires 62, 73 respectively from a two-core relay 46 having an armature 57 which moves from left to right at every odd impulse and from right to left at every even impulse. The first impulse from the line relay 52 energizes the winding 59, which locks itself and attracts the armature 57, which connects battery over an insulated tip contact 72 to the wire. 62, energizing relay I which locks itself over its right-hand winding and contacts of succeeding relays to ground at 68 and prepares a circuit for relay II. At the termination of the impulse the winding 59 is unlocked so that when the next impulse energizes winding 70 the armature 57 is moved to the left to connect battery to the wire 73, energizing relay II which locks itself, unlocks relay I and prepares a circuit for relay III, and so on. At the termination of the digit a slow-release relay 55 relapses and energizes relay 78, which opens the locking circuit of the counting relays and closes a circuit for winding 70, to ensure that the armature 57 is restored to its normal left-hand position. This circuit is also closed by the release magnet 25, which is energized over wire 83 when the registering equipment is released or over contact 81 if the subscriber abandons the call. Control of selectors and transfer of surplus record to a register-controller at a distant exchange. A register-controller of the type described, but arranged for seven digits instead of five, is shown diagramatically at the top of Fig. 3, and operates in conjunction with the constantly running ten-cam impulse machine IMP. On closure of the starting contact 352 a circuit 304, 345, 302 is completed through the closed first-digit contact of the register-controller and the corresponding impulse oam of the series 1 - - 0. The magnet 345 steps a local register 315 and the series relay 304 keeps the stepping- circuit closed over contact 353, independently of the starting contact 352, until the digit is completed. The relay 304 then relapses and energizes a shift magnet 347, so that in response to the next series of impulses, magnet 345 steps a second register 316. Relay 304 at the same time energizes magnet 301 to bring into circuit the closed second-digit contact of the register-controller. The third digit in the same way operates a third local register 317. The registers 315, 316, 317 close marking-circuits to control a panel selector of the kind described in Specifications 189,822 and 199,327, which selects a trunk to the required exchange, whereupon a relay 435 is energized to energize relay 307. A contact 348, closed after the operation of register 317, energizes relay 305, which locks itself and diverts the impulsing-circuit from magnet 345 to relay 309, which repeats the subsequent digits over circuit 308 to a register-controller at the wanted exchange.