Patent GB-115107-A (GB)
IPC: H04M15/10
Abstract: 115,107. Woods, A. E. May 4, 1917. Metering systems. - Effective calls are registered when both subscribers replace their receivers or ring off, the metering-circuit including contacts of relays under the control of the calling and called subscribers, respectively. In all the systems described, effective calls are registered by a momentary current produced when the operator withdraws the calling-plug after a conversation, and as the metering circuit includes a back contact of the supervisory relay in the answering cord, the operator may break down an incorrect connexion without registration. In one system, non-effective calls are registered manually, but in other systems these are registered automatically by additional relays or by the same control relay. First arrangement, Fig. 1, in which non-effectivo calls are registered manually by depression of key 47. The control relav X has an armature 14, Fig. 2, with an insulated end which normally rests below the armature 19 of a re-setting magnet 20. When the armature 14 is attached, the armature 19 falls so that it rests upon a pin 21, circuit being completed between the two armatures when the armature 14 again falls back. This. circuit includes the magnet 20, which raises the armature 19 so as to open the circuit and restore the armatures to their initial positions. The operating is as follows :-On the insertion of the calling-plug, the lamp 12 is energized over the back contact of relay X, and when the called subscriber replies, relay 8 energizes relay X which attracts its armature 14 and locks up over its right armature and the sleeve 40, shunting the lamp 12. When the called subscriber hangs up, relay 8 opens the shunt around the lamp 12. The calling supervisory lamp 33 is controlled in the usual manner. On the withdrawal of the calling-plug, relay X de-energizes and completes the metering-circuit from battery 44 through the operator's meter 17, armatures 14, 19, magnet 20, armature 23 of relay 24, and the calling subscriber's meter 18. The magnet 20 at once interrupts this circuit and restores the normal relation of the armatures 14, 19. If the called subscriber does not respond, relay X is not energized, so that the metering circuit is not completed on the withdrawal of the calling-plug. Second arrangement, Fig. 3, in which non-effective calls are registered automatically on the withdrawal of the calling-plug. In this case, the circuit of the metering battery 44 is prepared by an additional relay 51, the armature of which co-operates with the armature of a re-setting relay 53 as in the case of the armatures 14, 19, Fig. 2. The relay 51 is energized on the insertion of the calling-plug, and if the subscriber does not respond, the withdrawal of the plug causes relay 51 to de-energize and send a momentary impulse from'battery 44 over the armature 14 of relay X to the operator's ineffective call recorder 46. If the called subscriber replies, relay 8 energizes relay X which attracts its armature 14 so as to disconnect the non-effective meter 46 and connect in the effective meter 17 &c. The relay X also locks up over the sleeve circuit. When the operator withdraws the calling-plug, the relay 51 transmits a momentary current from battery 44 through the armature 14, magnet 50, operator's meter 17, armature 25, to subscriber's meter 18. The magnet 50 re-sets the armature 14. If the operator withdraws the calling-plug before the calling subscriber hangs up, as in the case of an incorrect connexion, current passes from the battery 44 through the magnet 50 and high resistance 172 to ground, thus re-setting the armature 41 without registering the call. Junction-line working to magneto exchange. The bushes of jacks of outgoing junctions to magneto exchanges are earthed through a resistance of such a value as to prevent the energization of the relay X when the supervisory relay 8 attracts its left-hand armature when a call is extended to the magneto exchange. The relay 8 is provided with a second armature 63 which is attracted only when the called subscriber rings off, thus strengthening the current over the junction so as to cause the relay to attract its armature 63, thus strengthening the current in the relay X sufficiently to energize it. Modified systems for registering effective and non-effective calls automatically. In one system, the relays X, 50, 51 are replaced by two pairs of relays, one pair controlling the effective meter and the other the non-effective meter. One relay of each pair serves only for restoring the armatures after metering. The other relay of one pair is energized on the insertion of the calling- plug and prepares the circuit of the non-effective meter, which is operated if the call is ineffective. The other relay of the other pair is energized when the called subscriber replies, and (1) prepares the effective metering circuit, (2) disconnects the corresponding relay of the other pair, and (3) disconnects the non-effective meter. In other systems, control relays are used having two armatures, one responding to a small current when the plug is inserted in the jack of the wanted subscriber so as to prepare the circuit of the ineffective meter, and the other responding to a stronger current produced when the wanted subscriber responds, so as to prepare the effective metering- circuit. In all these arrangements, a momentary contact is made on the de-energization of the relay. In the relay shown in Fig. 10, the armature 92 is connected by a strap 105 to a contact spring 103. When the magnet de-energizes, the spring 103 engages the spring 91 but the contact is immediately opened by the engagement of the end of the armature 92 with the inclined part 104 of the spring 91. In the relay shown in Fig. 13, the armature 122 is connected by a strap 133 to a spring 132, which, when the armature is attracted, passes over the insulated end 130 of a pivoted hook 120 provided with a bevelled surface 129. When the armature is released, the spring 132 engages a metal contact 131 until the hook 120 is raised by the engagement of the armature 122 with the bevelled surface 129. Other similar constructions using a spring connected to an armature by means of a strap are described. In a modification of the device shown in Fig. 2, the re-setting magnet 20 is replaced by a differential winding on the control relay, and the armature is polarized so that, when the metering-impulse passes through the second winding, the polarity of the core is reversed and one of the armatures is repelled so as to allow the other to return to its normal position.