Patent GB-543154-A (GB)
Title: Improvements in or relating to measuring and announcing charges in telephone systems
IPC: H04M15/38
Filed: 1940-08-21
Abstract: 543,154. Electric selective control. STANDARD TELEPHONES & CABLES, Ltd. Aug. 21, 1940; No. 13283. Convention date, Aug. 23, 1939. [Class 40 (i)] [Also in Group XXXIX] A system in which a calling party's meter is operated repeatedly during conversation is provided with apparatus which computes the charge for the call in money values as the metering operations occur and at the end of call transmits an oral announcement of the total charge to the calling party, this operation being initiated by the release of the called party or by a momentary opening of the calling party's loop. The announcements are supplied from common apparatus comprising a number of sound records certain of which are selected by the computing apparatus to express the appropriate sums. The computing apparatus is individual to a finder-selector link LC and comprises a units switch US, tens switch TS and hundreds or dollars switch HS, together with a switch SS which goes through a cycle to pick up the successive words of the announcement. The metering circuit includes a relay MI so that at each metering operation an impulse is delivered to the units switch US, which then takes a number of steps automatically under the control of markings on its bank US<SP>2</SP>. It is assumed that the unit of charge is 4¢ cents and that an odd half-cent is neglected in computing the total, so that in general US must advance 4 steps and 5 steps alternatively. The switches have actually 21 positions and it is arranged that they step automatically through unnecessary positions. The units switch US however assesses the number of cents up to 19 before transferring to the tens switch TS, but subsequently transfers at each decade. The tens switch TS transfers to the dollars switch HS at each rotation. The stopping positions of US are not necessarily the same for its successive rotations and these are therfore determined by a group of relays UA . . UI the condition of which varies according to the positions occupied by TS and HS. The announcing operation is initiated by the energization of relay ZA which results from the successive relapse of PSA, PSB when the called party releases or of SPA, SPB if the calling party opens his loop momentarily. The pick-up switch SS is started, and the calling line is tended to wipers SS2, SS3 the contacts of which are connected directly oc by way of the switches HS, TD, US, to receive the various components of the-announcements. The latter are recorded as a series of sound films such as 15, 16 on a rotating drum 10, each film being reproduced by a separate optical system. The switch SS stops in a series of positions determined by the condition of relays SA .. SG, which are in turn dependent on the positions of HS, TS, US, and remains in each position for a sufficient time for a component of the announcement to be sent to the calling party, stepping being resumed under the control of contacts 34 actuated by a cam 35 associated with the drum 10. Thus, for example, the switch SS would stop in positions 2, 3, 4, 7, 9, 11 and 13 to give the anouncement "the charge is one dollar and three cents." Special provision is made for giving the announcements "more than ten dollars" and "no charge," and for expressing the word "dollar" or "dollars" with a falling or rising inflection as it terminates the announcement or not.