Patent GB-497641-A (GB)
Title: Improvements in and relating to devices for determining telephone charges from manually set data
IPC: H04M15/38
Filed: 1937-04-19
Abstract: 497,641. Multiplying - apparatus. LEHNER, C., GADESMANN, M., LEICHTHAMMER, K., and LEICHTHAMMER, H., (trading as TELEFONBAU UND NORMALZEIT LEHNER & CO.). April 19, 1937, No. 11190. Convention date, April 18, 1936. [Class 106 (i)] The cost of a telephone call is automatically determined when a number or letter combination characterizing the called exchange is typed on a typewriter, followed by a letter representing the tariff (day or night), and a number representing the time occupied by the call, the cost being either typed or indicated. A key KK, Fig. 1, is first depressed to operate a relay C which becomes locked and holds operated all contacts c. Typewriter keys corresponding to the characterizing number of the called exchange are then depressed in turn, this number in the present instance containing three figures. Each key earths a different code combination of five bars PB. Key KK also causes a controlling switch St to move from position O to position I, relays RH1 ... RH5 thus operating to register the code corresponding to the hundreds of the characteristic figure on contacts rh1 .. rh5. When the hundreds key is released, a short circuit (not shown) is removed from across a relay F1, this relay then operating to close contacts f whereby controlling switch St is stepped to position II. The tens digit of the characteristic figure is then registered by relays RZ1 ... RZ5 on contacts rz1 ... rz5. The units figure is registered by relays RE1 ... RE5 on contacts rel ... re5 and the time factor by relays RG1 ... RG5 on contacts rg1 ... rg5. The last operation is preceded by depressing one of two keys KN, KT, the key KN energizing relay N, Fig. 2, to close contacts n to set the device to determine the cost according to the night rate. Every called exchange lies in one of five zones I ... V and switches H, Z, E are so connected that when set in accordance with the characteristic figure now stored in the relays RH1 &c., they earth that zone point I ... V corresponding to the called exchange. The switches H, Z, E are set in the following manner. A rotary switch A, Fig. 1, having arms aI ... aIV is actuated by a driving magnet Da when the controlling switch St is in positions II .. V. An impulse-generating relay Az by contacts az2, Fig. 2, operates the stepping magnet Dh of the switch H until the arm aI finds the earthed contact corresponding to the hundreds digit of the characteristic figure, a relay P then operating to open contacts p3 to stop switch H. A relay U1 then operates through contacts p4, f1. The contacts u1 of relay U1 change over the connections to switch arm aII and driving magnet Dz and the tens digit is transferred to Z. The units digit is next transferred to E and finally the stepping magnet Dt sets a switch t to a position corresponding to the time factor. A relay V then closes a contact v to allow an interrupter RU1 to energize a driving magnet DZ1 which drives the hundreds arms Z 1 of a result selecting switch until the earthed contact determined by the set position of the time factor switch t is found by the lowest arm Z1. A relay Pz then operates, stops DZ1 by contacts pzl and starts the driving magnet Dg of a result transmitting switch G having arms g1 ... g8. The result selecting switch Z1 .. Z3 is connected to the result transmitting switch G by distributer frames VSt and TSt having connections arranged in them in such a way that the earth of the selected zone point is connected through the set hundreds arm of the result selecting switch Z1 to that contact g1 corresponding to the hundreds digit of the resultant cost. When the arm g1 finds this earthed contact, a relay Pg operates and, by contacts pg1 and arms g4 . . . g8, energizes coding relays W1 . . W5 which energize a selection of five circuits to give a code signal corresponding to the hundreds digit of the result. This signal either operates an indicating device or, through a printing relay Dr, actuates the typewriter key corresponding to the digit concerned. The tens and units digits of the result are similarly indicated or printed.