Patent GB-265653-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/42
Filed: 1925-10-09
Abstract: 265,653. Automatic Telephone Manufacturing Co., Ltd., and Ostline, J. E. Oct. 9, 1925. Automatic exchange systems. - An office register extends a one-wire connection to a sending machine individual to the wanted exchange. and the machine sends back the digits of the appropriate routing-number in code form to relay registers in the register-controller. The office register comprises a minor switch M, Fig. 2, which responds to the first digit and picks out one of eight wipers of a Strowger switch ED, which is set by the second and third digits. The letters I and O are avoided as initials of exchange names, so that these have only eight numerical values. The terminals of the office-register are jumpered to terminals of switches such as SS individual to different exchanges. The wipers 158, 159 of the switch SS act as a single wiper on a bank of double length, and have five terminals for each routing digit, of which there may be any number up to six, the terminals being connected some to battery and the rest to ground. At each step of the switch SS one or other of two polarized relays 101, 103 in the register-controller is energized and causes a switch DS to step synchronously and to bring successively under control the relays of six registers, of which only the first 171 - - 175 and the last 181 - - 185 are shown. A register relay is energized if the corresponding terminal in the switch SS is connected to ground, but not if it is connected to battery. The relay registers control a sending switch SCS, which starts sending a moment after the switch SS has started. The fifth relay such as 175 of a register is energized for all values of a digit up to 5. For example, if the first digit is 6 the relay 171 alone is energized and grounds the 6th stop-wire 78, but if the digit is 1 the relay 171 is energized along with relay 175 and grounds the 6th stop-wire, the relay 175 at the same time grounding the 5th stop-wire, and the two relays jointly grounding the 1st stop-wire, which alone is effective. If the digit is 5 the relay 175 is energized alone, and if the digit is 0 all the relays 171 - - 175 are left inert. Provision is made for skipping digits and for setting up calls to toll and other operators. The register-controller is of similar type to that described in Specification 233,007. According to the Provisional Specification, the machine SS, instead of controlling relay registers, may control the setting of a secondary office-register of Strowger type in the register-controller. Recording dialled number. Relay 5 in the incoming control circuit energizes relay 7, which grounds the wires 61, 67,. and two-step relays 13, 22 become fully energized at the next closing and opening of the impulse contacts respectively. Relay 22 closes circuit 72, to drive the switch OCS, Fig. 3, to 2nd position, and then at once relapses, its circuit being opened at wiper 22. The first digit is repeated by relay 5 over circuit 70, 211, 138 to the magnet 129 of the switch M, the second and third digits to the magnets 132, 133 of switch ED, and the remaining digits to the number registers M1 - - M4. the relays 27, 29 at the end of each digit sending an impulse over circuit 63 to step the switch DD. Control of relay registers by the machine SS. In its 4th position the switch DD closes a circuit 137 to energize relay 126, Fig. 2, and if the switches SS are all in normal position, or when next they are all at normal, a circuit 163 is grounded to energize relay 123, which locks itself through the home terminal of the wiper 150 of switch DS and connects relay 121 in series with the stepping-magnet 160 of the switch SS, which is thus started from normal to make a complete rotation under control of its wipers 156, 157. Relay 121 energizes relay 117 which de-energizes relay 126, starts the sending switch SCS as described in the next paragraph, and connects the machine SS to the polarized relays 103, 101, which are connected on the other side to halfbattery potential. At each step of the machine SS one of the relays 101, 103 is energized, with the result that in either case a relay 105 is energized and supplies an impulse to magnet 149 to to step the switch DS, but if the relay 103 is energized the circuit of relay 105 passes over wiper 154 or 155 and includes a register relay, which also becomes energized and locks itself to the circuit 67. Relay 123 is kept energized by relay 105 as long as the code transfer operations continue, and then relapses and disconnects the circuit to the machine SS. Control of sending switch SCS by the relay registers and by registers M1 - - M4. Relay 117 closes an impulse circuit 61, 210, 137, 118, 136, 202, 62, 26, 23, 41 through the lower winding of two-step relay 22, which locks itself and transfers the impulse circuit to magnet 53 to drive the switch SCS. Relay 35, energized as long as the switch is off-normal, closes circuit 74 for the back-stroke magnet 206 of switch OCS, opens a shunt across the impulse springs 21, and closes a shunt across the line winding of polarized relay 33, so that impulses are sent out cleanly over the circuit 2, 3. The switch OCS being in its 2nd position, ground is connected from circuit 61, 210, 137, 118, 136 over wipers 203, 204, wires 141, 142 and contacts of the 1st relay register 171 - - 175 to one or more stop-wires 75 - - 83. As soon as the wiper 55 reaches the first grounded stop-wire, relay 39 is energized, locks itself under control of relay 35, shunts the outgoing impulse circuit, unlocks relay 22, and closes a self-interrupting circuit for magnet 53 to drive the switch SCS quickly to its next normal position. Relays 35, 39 then relapse and magnet 206 is de-energized to drive the switch OCS to its 3rd position, in which ground is connected to the stop-wires through contacts of the 2nd relay register. Sending of the 2nd digit commences with the energization of relay 22 when relav 39 relapses. All the six exchange digits are sent in the same way, and the four numerical digits are then sent under control of the registers M1 - - M4. For the 1st, 2nd and 3rd numerical digits, the circuit 62 of the starting relay 22 includes an off-normal contact of the next register ahead. Release of register-controller. When all digits have been sent the switch OCS arrives in its 12th position and grounds circuit 71 to energize relay 44, Fig. 1, which locks itself, de-energizes relays 13, 7 and is thereby unlocked. A circuit 68 for restoring the switches SCS, OCS, ED, DD, and M1 - - M4 is closed first by the energization of relay 44 and later by the relapse of relay 7. and a relay 49 in this circuit keeps the wire 4 grounded to mark the register-controller busy until all the switches are restored. The relapse of relay 7 opens the locking circuit 67 and the relapse of relay 117 closes a restoring circuit for the switch DS. Skipping digits. If the routing-number of the wanted exchange includes fewer than six digits, the terminals corresponding to unwanted digits are left blank in the machine SS, so that the switch DS is moved only to its 5th, 10th, 15th &c. position. For example, if the routing-number has only a single digit the switch DS stops in its 5th position, and after the single digit has been sent out the switch OCS in its 3rd position closes a circuit 203, 143, 162, 152, 107, 114. Relay 114 is marginal and does not respond because of resistance 162, but relay 107 locks itself and connects all the wires 143 - - 147 over circuit 69, 20, 73, 205 to magnet 206, so that the switch OCS steps itself quickly through the five unwanted positions, the stop-sending relay 39 being kept energized over 43, 34, 38, 69. Calls to toll operator. The digits TOL pick out a machine SS in which the terminals representing the appropriate 3-digit routing-number are followed by as many battery-connected terminals as are necessary to bring the wiper 153 of switch DS to the terminal of circuit 145. After the three digits have been sent out, the switch OCS moves to its 5th position and closes circuit 203, 145, 153, 107, 114. Relay 114 locks itself and grounds circuit 71 to energize relay 44 to release the register-controller at once. Calls to enquiry operator. In response to the single digit O, the switch M directly picks out the appropriate machine SS and energizes the starting relay 126.