Patent GB-180362-A (GB)
Title: A telephonic conversation meter
IPC: H04M15/10
Filed: 1920-12-21
Abstract: 180,362. Ferry, R. Dec. 21, 1920. Meters and metering systems.-A device for controlling the metering of calls according to both their number and duration comprises two electromagnets, one of which is energized at the beginning of the conversation to operate a set of contacts in a meter circuit, so recording one unit; whilst the second electromagnet is periodically energized throughout the conversation and steps forward a moving member which, after moving through a distance corresponding to a unit of conversation, actuates again the same set of contacts to record another unit. In one form, Fig. 3, a wheel r having ten large teeth is stepped round one tooth at the beginning of each conversation by the electromagnet m, which also closes contact z' in the circuit of the second electromagnet n. Throughout the conversation the periodic energization, say every twenty seconds, of the magnet n steps round a second wheel l integral with the wheel r and having ninety teeth. A third wheel r<2> integral with the wheels r, l carries studs which at every movement of the wheels through a distance equal to a unit of conversation, operate, by means of a pawl v, contacts z<4>. in a circuit controlling a recording meter. An additional recording device to be directly operated may be fixed on the shaft of the wheels l, r. When working with a high frequency of pulsations, the wheel l may be indirectly operated through a multiplying gearing. In a modified device, Fig. 7, the Contacts z<4> are directly operated by the magnet m at the commencement of the conversation, whilst the metering according to duration is effected by a reciprocating rack l which is periodically stepped downwards by the pawl k operated by the magnet n. At the end of its downward travel the rack l tilts the anchorshaped member l<1>, which causes the spring l<5> to operate again the contacts z<4> and also releases the pawls k, o from the rack, which is restored to normal by a controlling spring and at the end of its travel restores the member l<1> also to normal. The rectilinear rack l may be replaced by a curved rack or by a ratchet wheel. Fig. 8 shows the circuit arrangements with the meter-controlling device arranged on the third wire of the subscriber's jack circuit at the exchange. The magnet m, energized when the plug is inserted in the jack, closes a contact a in the circuit of the magnet n which is periodically energized by a battery b in series with an interrupter c. The switch 3 closed at the passage of each unit of conversation energizes a relay 4 controlling a switch 1 which reverses the current over the subscriber's line, thus energizing the polarized electromagnets of the subscribers' individual meters which may be arranged in shunt with the line both at the substation, and at the exchange as shown by dotted lines 5. The magnet 5 may also control a recording device comprising a rod 7 providing with a stylus impressing a strip of paper which is periodically advanced by a relay 8 also controlled by the battery b End .interrupter c. As an alternative.. the switch 1 may be operated by a rod in direct mechanical connection with the wheel r. In the arrangement shown in Fig. 9, the polarized magnet 25 corresponds to the magnet m of the device shown in Fig. 3. When the called subscriber replies, the energization of the supervisory relays 6, 6<1> connects the positive pole of the dynamo 27 to the third wire 41, thus reversing the current in the magnet 25 which energizes in series with the relay 3 in tie cord sleeve circuit. The energization of the magnet 25 effects the registration of the call and its duration in the manner previously described. The relay 3 locks itself in a circuit independent of the contacts 7, 8 controlled by the relay 6, 6<1> and prepares a circuit for relay 4. At the end of the conversation, when both subscribers hang up, relay 4 energizing over a circuit 16, 10, 13, 12, 27 disconnects at its armature 31, the dynamo 8 from the third wire 41 and connects at its armature 17 the negative pole of the main battery over the lead 5 and the winding 15 thus again reversing the current in the third wire and causing the magnet 25 to cease to operate. Relay 4 de-energizes and the system is restored to normal when the plugs are taken down. Fig. 10 shows an arrangement in which the meter-controlling device is arranged on the cord circuit. When the called subscriber replies, the relays 28, 29 energize the magnet 34 over the contacts 30, 31 and orepare the circuit for the magnet u which is periodically energized over the interrupter c. The magnet 34 energizes the high-resistance winding 25 over a circuit from battery, contact 32, and the third wire 41, and may also light a pilot lamp 40<a>. At the passage of each unit of conversation, the trip-gear A is operated by the studs on the continuously rotating wheel, as shown in Fig. 3, to connect the battery directly to the third wire over the contacts 35, 37 thus sending an impulse over the third wire to operate a subscriber s meter. The registration ceases as soon as one subscriber hangs up.