Patent GB-158222-A (GB)
Abstract: 158,222. Automatic Telephone Manufacturing Co., Ltd., (Assignees of Willis, B. D.). Jan. 28, 1920, [Convention date]. Automatic exchange systems; metering systems.-In a measured service automatic exchange system, the calling subscriber's meter is automatically operated a variable number of times depending, first, on the apparatus taken into use in establishing the connection, and, second, on the duration of the conversation. Timecontrolled mechanism individual to some particular apparatus or line taken into use assesses an initial charge on the response of the wanted subscriber, and subsequently registers a further fixed or variable charge, independent of the initial charge, as predetermined time intervals during the conversation. In the arrangement shown in Figs. 1 aid 2, when a calling subscriber A removes his receiver, his line is extended by the line switch C in the usual manner to an idle group selector D, which is operated by the line relay 50 and the vertical and rotary magnets 56, 54 in known manner to extend the call to an idle repeater R, the trunk conductors 200, 201 from which lead to the distant exchange. Individual to the repeater R is an auxiliary metering switch P, comprising two semicircular rows of bank contacts adapted to be engaged by two wipers 153, 154 mounted on a common shaft. Connection having been extended to the distant exchange, the subscriber dials the remainder of the wanted number, with the result that the line relay 101 is de-energized and a bridge across the conductors 200, 201 interrupted to effect the operation of the remaining switches in the distant exchange in the usual manner. When the wanted subscriber removes his receiver, the direction of current in the lower winding of the polarized relay 104 is reversed, the relay 104 responds and energizes the relays 100, 105. The relay 100 connects an additional pair of condensers and includes the lefthand winding of the impedance coil 107 in the bridge across the conductors 200, 201 to increase the efficiency of the talking circuit. The relay 105 locks itself at armature 120, and at armature 121 closes a circuit through the stepping magnet 150, which rotates the wipers 153, 154 one step each time the clock mechanism T earths the common conductor 163, say every three seconds. When the wiper 154 reaches the contact 164, the relay 106 of the repeater R is energized and causes an increased flow of current through the marginal relay 42, which closes the circuit of the magnet of meter M. One unit charge is thus registered each time the relay 106 responds. As the wiper 154 advances to engage contacts 166 and 167, the relay 106 is energized twice over the armature 155 and two further units are registered. These three units constitute the initial charge and nothing else happens until the contact 170 is reached, when the relay 151 is locked energized, and at armature 155 disconnects the contacts 166 and 167 from the relay 106. After the expiration of predetermined intervals, say of one minufe, the contacts 172, 173 are successively engaged and further unit charges registered. When the wiper 154 arrives at the last contact, the wiper 153 engages the contact 174 and the release magnet 152 is operated to restore the wipers to normal and disconnect contact 164 from the relay 106 whilst the wipers are returning. The magnet 152 is maintained energized by the wiper 153 until the first contact is reached. By the time the stepping-magnet 150 receives another impulse, the wipers are ready to be again started on their rotation, the meter M being operated at intervals of one. minute as long as the subscribers converse, and the switch P being released as many times as necessary. The contacts 166, 167, 170 remain dead, their circuits being broken by the armatures of the relay 151. Release of the line switches is initiated in the usual manner by the de-energization of the line relay 101. Upon the relapse of the release relay 102, the release magnet 152 of the switch P is energized, and establishes a holding circuit for itself over the wiper 153 until the switch is restored to normal. By suitably arranging the connections to the contacts engaging the wiper 154 of the auxiliary switches associated with the different groups of repeaters, a variable initial charge and variable or fixed charges for variable time intervals may be registered according to the exchange in which the wanted subscriber is located. Specification 122,747 is referred to.