Patent GB-155088-A (GB)
Title: Improvements in or relating to coin freed prepayment devices for telephone systems
IPC: H04M17/02
Filed: 1919-10-31
Abstract: 155,088. Automatic Telephone Manufacturing Co., (Automatic Electric Co.). Oct. 31, 1919. Exchange systems; coin-freed systems. - Relates mainly to systems in which a coin must be inserted before a call is made, the coin being refunded if the call is ineffective. The coin is collected or refunded, without any special operation on the part of the calling subscriber, and in most of the arrangements described this occurs when the subscriber hangs up his receiver, a momentary strong positive or negative current, according as the call is effective or ineffective, operating a polarized magnet to collect or refund the coin. In one modification, the coin is collected when the called party replies, and is refunded, if the call is ineffective, when the calling party hangs up his receiver. The relay arrangements at the exchange for determining the collection or refund of the coin may be individual to the subscriber, or located in a common trunk associated with a selector or impulse-repeater. Arrangements are provided whereby the called party may pay for a call, the coin being collected or refunded at a time determined by the operator. First arrangement, Fig. 1. The insertion of a coin opens contact 11, 12, which normally shortcircuits the impulse-sender 7, and closes contact 10, 11 to connect the coin. controlling magnet 13 to line. When the subscriber A removes his receiver, he is connected by his rotary line switch C, which operates in known manner, to an idle selector trunk, with which is associated a group of relays D for connecting a high-potential positive or negative battery K, M to the calling line when the subscriber hangs up. The circuit of the selector line relay over the calling line includes relay 28, which is energized, and the upper winding of a differential relay 27, which is not energized at this stage since the lower winding opposes the upper. Relay 28 energizes relays 44, 45, 48, and 51. The call is set up in the usual manner, and, if the called party answers, the current through the upper winding of relay 27 is reversed, so that this relay is energized and prepares the circuit of the positive battery K. When the calling party hangs up, the selector and connector release, opening the circuit of relay 28, whereas relay 27 is retained energized by its lower winding. Relay 28 open-circuits relay 45, which momentarily energizes relay 57 to prevent switch C from releasing, and relay 44, which allows relay 48 to complete the circuit of battery K over the calling line to collect the coin. If the called party is busy or does not reply, the operation is similar, but in this case the relay 27 is not etnergized and the battery M is connected to line to refund the coin. Second arrangement. This is similar to that shown in Fig. 1, except that the magnet 13 is connected across the two line wires by contacts controlled by the coin and switch-hook respectively. Third arrangement. The cord-circuit shown in Fig. 3 is particularly intended for use in systems in which the called party is selected over numerical switches by an operator and in which the called party inserts a coin, which is collected or refunded under control of the operator. The connexion is established in known manner, and when the called party rephes, the operator asks him to deposit a coin, which she collects by depressing key 103 which causes relay 104 to connect a high positive potential 105 in circuit with a polarized relay in series with the connector line relay, this polarized relay in turn connecting a high positive potential to the called line. If the operator wishes to refund the coin, she depresses key 110 to connect negative potential to the called line. Fourth arrangement, Fig. 4, in which the means for determining the collection or refund of the coin is associated with an impulse-repeater G. When the calling party removes his receiver, the line is extended in known manner to the line relav 100, which energizes the usual release relay 101 and closes at contact 102 a circuit for the selector line relay, including the lower winding of relay 120, which is not energized owing to the opposing action of its upper winding. During the impulsetransmission, a relay 128 disconnects the lower winding of relay 120 and relay 121 from the trunk 117, 118. When the called subscriber answers, the current is reversed through the lower winding of relay 120, thereby energizing a self-locking relay 133 which prepares the circuit of the positive high potential battery X. When the calling subscriber hangs up, relay 100 energizes relay 128, which momentarily energizes relav 140 to connect the battery X to line to collect the coin. If the call is ineffective, relays 120, 133 are not energized, and battery Y is connected to line to refund the coin during the release. Fifth arrangement in which the means for determining the collection or refund of the coin is associated with an impulse-repeater individual to the calling line. This is similar to the arrangement shown in Fig. 4, except that an additional relay is provided to disconnect the repeater when the line is called. Sixth arrangement, Fig. 6, in which the means for determining the collection or refund of the coin is associated with the subscriber's line switch. When the subscriber removes his receiver, his line relay 158 causes the rotary magnet 160 to rotate the switch J to find an idle connector L, whereupon the switching-relay 159 extends the calling line to the connector line relay 172, the circuit including the right-hand winding of a relay 157 which is not energized because of the opposing action of the left-hand winding. When the called party replies, the back-bridge relay 176 reverses the current in the calling line, thereby energizing relay 157 to prepare the circuit for the positive battery P, which is connected momentarily to line to collect the coin when the calling party replaces his receiver. If the call is ineffective, relay 157 is not energized, and battery Q is connected to line to refund the coin. An extra relay 173 in series with the lower winding of the connector line relay 172 is provided to ensure the release of the connector, in case the line relay 172 should remain energized over its upper winding and the sub-station magnet 152. Seventh arrangement. Positive high potential current is sent to line to collect the coin immediately after the called party replies, whereas, if the call is ineffective, negative current is sent to line to refund the coin when the calling party replaces his receiver. Eighth arrangement. The differential relay, which is energized when the called party replies, directly prepares a circuit for the positive or negative high-potential battery, this circuit being completed momentarily by a slow-release relay controlled by a relay connected to the third or release wire.