Patent GB-731112-A (GB)
Title: Token-operated telephone for automatic local calls and automatic and manual long-distance calls
IPC: H04M17/02
Filed: 1953-03-24
Abstract: 731,112. Automatic exchange apparatus. S.T.I.P.E.L. SOC. TELEFONICA INTERREGIONALE PIEMONTESE E. LOMBARDA. March 24, 1953 [March 24, 1952], No. 8124/53. Class 40 (4). [Also in Group XVIII] A telephone prepayment apparatus for automatic local and toll calls collects a single coin or token at the end of a local call but, for toll calls to other networks, the collection of coins or tokens begins when the call is answered and continues periodically at a rate which is controlled by impulses from a charging device at the exchange and is variable according to the distance of the call. In one form, the apparatus has two token slots, one for a number of tokens U corresponding to the charge for a local call and the periods of a toll call and the other for a single token M, of half the value of the token U, for initiating a toll call and for charging for half-periods. Two other forms having a single slot for tokens U are described and, in these forms, the extra charge for a toll call may be made by a compensatory shortening of the time periods allowed for each token or by issuing supplementary impulses from the exchange. The channel leading from the slot for tokens U may hold up to fourteen tokens so that a toll call may be fully prepaid but a fifteenth token, if inserted, will be deflected to a refund shoot 32. The receiver hook lever 6 is connected by a hook 10 to a second lever 7 and, when the receiver is lifted, both levers move up and the lever 7 operates contacts g to close the line and connect the ringer SN through an impedance coil IM, as shown in Fig. 29; a lever 14 connected to the lever 7 allows the closing of contacts is in a circuit containing a rectifier RD through which the charging impulses pass to electromagnets MD and MI for the collection and refunding of tokens. The tokens U (or a single token, in the case of a local call) are held up in a shoot, and the foremost tokens lower a spring-loaded lever to open contacts gu1 thus breaking the short-circuit formed across the contacts cc, ci of the calling dial by contacts gu1 and md1 and making it possible to select a call on the dial. At the same time, in the form of apparatus having two token slots, a token M (if a toll call is required) is stopped in a shoot and lowers a spring-loaded lever to open contacts gm and prevent short-circuiting of the line through contacts md111 which are closed later. On the reply of a called party on a toll call, the exchange sends an impulse which operates the electromagnet MI to withdraw a stop allowing the first token U to be collected. After the predetermined period, a second impulse operates the electromagnet to return the first stop and release a second stop that has been holding up the next token U. The first impulse also energizes the electromagnet MD by which deflectors deflecting the tokens into the refund shoot are withdrawn so that the tokens pass into a collection box. The electromagnet MD is mechanically held in its attracted position during the entire period of the call and it changes over contacts md so that the calling dial and a manually-operated key Ti are inoperative and the circuit is prepared for preventing conversation if all the inserted tokens U are collected, resulting in the closing of contacts gu1; insertion of one or more tokens U will, however, enable the conversation to be resumed. On replacing the receiver, the second lever 7 is disengaged from the hook lever 6 and descends independently, its descent being retarded by an air cylinder 12 to allow time for the token collecting or refunding operations after the line contacts g have been opened. These operations are controlled by dogs on an arm 13 and by the lever 14. If the receiver is replaced after an odd impulse, the token stops are operated so that the token M of half value is collected and, if after an even impulse, so that the foremost token U is collected. After the collecting operation, the deflectors in the token shoots are returned to a deflecting position, the electromagnet MD is released and the lever 14 releases the remaining tokens U and the token M, if present, into the refund shoot. On termination of a local call, an impulse from the exchange operates the electromagnets to collect the token U. The lever 14 also opens the contacts ls in the electromagnet circuit. If the called party fails to answer or the line is engaged, replacing the receiver will refund all the tokens but, if the call is to be repeated and it is desired to avoid a refund, the key Ti may be momentarily depressed to clear the line. In two modified forms of the apparatus, only a single slot, for tokens U, is provided and the contacts gm and md111 are eliminated, as shown in Fig. 37, which shows the positions of the contacts when the receiver is replaced. In one form, tokens are collected at the rate of one for each two charging impulses and, in another form, one token is collected for each impulse. The calling dial may be arranged so that it will not operate on certain fast digits required for a toll call unless the additional token M or the second token U, according to the type of apparatus, is present. For the apparatus with two token slots, the dial contacts ci are short-circuited through the contacts gm operated by the token M and through contacts cl. Fig. 37, which are closed if the toll call first digits are selected. For the apparatus with a single slot, in addition to the contacts cl, the contacts gm are again fitted and are operated by the second token U.