GB485117A - Improvements in or relating to prepayment apparatus for telephone systems - Google Patents

Abstract

485,117. Substation equipment. ENGEL, H. Nov. 16, 1936, No. 31297. Convention date, Nov. 16, 1935. [Class 40 (iv)] [Also in Group XVIII] At a prepayment substation, a number-selecting device and a coin-receiving device are interconnected by control means which permit the transmission of selecting impulses by the numberselecting device only when the amount prepaid corresponds to the fee chargeable for the number selected. As applied to apparatus in which the number selector has a lever for each digit the four levers which select the code number determining the charge are connected with respective insulating segments L, M, N and O passing between pairs of contacts interposed in a series of parallel circuits arranged between a motor D operating the impulse transmitting mechanism and an arcuate series of contacts engaged by a contact arm c of a coin-summating mechanism S. When, as shown, there are six rates of charge, six parallel circuits are provided, and six arcuate series of ten holes (corresponding to the digits 0-9) are provided in each of the segments. Contact elements are inserted in certain of the holes in such a manner that, when a number is selected, the four pairs of contacts of the appropriate one of the six parallel circuits are closed. If the correct value of coins is inserted into the apparatus, the coin summating mechanism S advances its contact arm c to engage the contact connected to the circuit completed by the segments L, M, N and O, and the motor D is energized to transmit the selecting impulses for completing the connection. A second contact arm a of the coin summating mechanism S moves over contacts to transmit audible impulses to the exchange to enable the operator to check the amount inserted for non-automatic calls. Different coins are inserted into separate slots and are received by corresponding inclined plates X, Y and Z on a counterbalanced rocking arm P. Each coin depresses the arm P until it rolls back off the plate X, Y or Z, the inclinations of the latter being so adjusted that the rotations of the arm P are proportional to the three coins. The rotation, or successive rotations when coins are inserted in succession, are transmitted through a one-way-drive ratchet and pawl to the contact arms a and c, which consequently assume a position corresponding to the total value of coins inserted. The contact arms are restored when the receiver is replaced. Relay contacts n connected between pairs of the contacts engaged by the arm c enable the charges to be reduced, at night time for example.