Patent GB-249248-A (GB)
Title: Improvements in or relating to automatic or semi-automatic telephone systems
IPC: H04Q3/42
Filed: 1925-01-06
Abstract: 249,248. Automatic Telephone Manufacturing Co., Ltd., and Tench, F. Jan. 6, 1925. Automatic exchange systems. - An automatic switch, particularly suitable for use as a code switch in a register-controller of the. code-translating type, is so arranged that certain of its wipers are connected up successively to control different operations, such as the transmission of routing digits, after which it is moved to a new position in which one or more of the same wipers are used to control further operations. The switch may also be adapted to hunt automatically under the control of one or more of its wipers (for example for contacts marked by registers), and afterwards advance a predetermined number of steps to a position in which the wipers previously used to control hunting, and if necessary other wipers as well, are then used to control other operations, such as the transmission of routing digits. Other features of the system described in detail below are claimed in Specification 250,510. In the arrangement shown, the exchange digits are recorded on registers M1 - - M3, Fig. 2, after which a code switch CS, Fig. 3, corresponding to the first exchange digit hunts to find contacts in the banks of its three, upper wipers marked by the registers M1 - - M3. A shunt relay 208 energizes when these contacts are found, arrests the code switch CS, restores the registers M1 - - M3, and starts the sending of the routing digits under the control of the impulse sending switch IS, Fig. 4. In the meantime the numerical digits are recorded on the registers M4, M1 - - M3. If the exchange routing number comprises only three digits, the determination of these is effected over the three lower wipers of the code switch CS, after which the outgoing control switch OCS, Fig. 4, ships to its seventh position, in which the transmission of the numerical digits is started. If the routing number consists of five digits, the determination of the first two is effected over the two lower wipers of the code switch CS, after which earth is extended over wiper 203 to advance the switch an extra step and energize a relay 217, which connects up the three upper wipers to the control switch OCS. The wipers 203, 202, 201 are now successively brought into use to control the sending of third, fourth, and fifth routing digits, and the wiper 200 is connected up to cause the control switch OCS to skip its sixth position. The wiper 200 may, however, be used to control the transmission of a sixth routing digit. Should it be necessary to send more than six routing digits, the wipers 204, 205 may also be used for controlling digits after the extra step is taken. The extra step may be taken by the switch CS before any routing digits are transmitted. The numerical portion of the number is sent by the registers M4, M1 - - M3 which transmit complementary series of impulses as they are advanced in succession to a subnormal position. All the switches composing the register-controller are 25-point single motion switches provided with as many normal positions as the arrangement will permit. Provision is made for calling a zero operator and for preventing the sending apparatus from catching up the registering apparatus. Setting of register-controller. A calling subscriber is extended in known manner over a line switch to a relay group associated with a first selector trunk from which it is assumed that the register-controller shown is taken into use by a hunting switch. The series of impulses corresponding to the three exchange digits arrive over the conductor 94, Fig. 2, and are directed in the usual way over wiper 120 of the incoming control switch ICS in succession to the stepping magnets 121, 131, 134 of the registers M1, M2, M3. The first numerical digit is directed in the fourth position of the switch ICS to the stepping magnet 137 of the register M4. When the code switch CS, Fig. 3, has found the contacts marked by the registers M1, M2, M3, as described in the next paragraph, the relay 208 pulls up and earths conductor 174, thereby energizing a relay 150, Fig. 2, which locks up over wiper 141 and completes restoring circuits for the registers M1, M2, M3 over armatures 153, 154, 155. The three remaining numerical digits are now sent to the registers M1, M2, M3 in the fifth, sixth, and seventh positions of the switch ICS. On the first impulse being sent to register M1, relay 151 energizes, locks up, disconnects earth from wire 167 so that when the registers M1 - - M4 restore again they will stop in a sub-normal position, and removes battery from wiper 130 to prevent the energization of the test relay of another code switch, the wipers of which may be resting on contacts subsequently marked when the registers M1, M2, M3 are set by the numerical digits. Transmission of the exchange, code. As soon as the third exchange digit has been recorded on the register M3 and the switch ICS moves to its fourth position, the wiper 141 is grounded, and a circuit is completed over armature 145 and wiper 126 of the first register M1 for the stepping magnet 206, Fig. 3, of the code switch CS assigned to the particular first exchange digit recorded on the register M1. The code switch CS now hunts for contacts marked by the registers M1, M2, M3, in the banks of its wipers 200, 201, 202. Assuming first that three routing digits are required to be sent and that the registers M1, M2, M3 haev been set upon their third, ninth, and fourth contacts respectively, the second contact of the first wiper 200 is earthed over lead 175 and wiper 125 of the register M1, the second contact of the second wiper 201 is connected to battery over lead 176 and wiper 130 of the register M2, and the second contact of the third wiper 202 is earthed over wiper 143 of the register M3. Consequently when the code switch CS arrives in its second position, the shunt-wound test relay 208 energizes over both its windings, arrests the switch CS and extends its wipers 203, 204, 205 to the outgoing control switch OCS, and energizes relay 150, Fig. 2. Relay 150 restores the registers M1, M2, M3 as previously described and grounds wire 180. thereby (1) energizing relav 231 which closes locking circuits for the shunt-wound relay 208, and (2) closing a circuit for the stepping magnet of the impulse sending switch IS over 306, I, 322, 305, 331. The switch IS is now stepped round until its wiper 326 engages a stop conductor to which earth is connected over wiper 304 of the outgoing control switch OCS in its first position, wiper 205 of the code switch CS, and the independent distributing frame IDF. At the first step of the switch IS, a relay 308 energizes and removes a shunt from the impulsing contacts 302 of the magnet 317. so that at each subsequent step the impulsing loop across the leads 91, 92 is opened at these contacts. When the marked stop conductor is engaged, stop relay 312 is energized, locks up, shunts the impulsing contacts, and closes a restoring circuit for the switch IS. On this switch arriving at a normal position, relays 308, 312 deenergize, and between their relapse a current impulse is sent to stepping magnet 323 of the control switch OCS which advances to its second position. The impulse switch is now restarted and a series of impulses is transmitted determined by the jumpering of the contact engaged by wiper 204 of the code switch. In a similar manner in the third position of the switch OCS an impulse series determined by the jumpering of the contact engaged by the code switch wiper 203 is sent over the loop 91, 92. In the fourth, fifth, and sixth positions of the switch OCS circuits are closed over armatures 212, 211, 223 to cause it to skip to its seventh position. Assum. ing now that the registers M1, M2, M3 were set in response to the exchange digits to a position corresponding to an exchange for which five routing digits are required. After the code switch CS has found the marked contacts, the wipers 205, 204 of the code switch are successively brought into use as before to control the sending of the first and second routing digits in the first and second positions of the control switch OCS, but in the third position of the switch OCS the earth connected to the code-switch wiper 203 is extended over a contact, such as 246, to the stepping magnet 206 and to a relay 217. The code switch is thereby advanced one step, and the relay 217 locks up, unlocks the shunt-wound relay 208, and connects the wipers 202, 201, 200 to the fourth, fifth, and sixth contacts in the bank of wiper 304 of the control switch. The jumpering of the contacts 251, 252, 253 on which the code-switch wipers 203, 202, 201 now rest, determines the third, fourth, and fifth routing digits, which are sent out in succession in the same way as the others in the third, fourth, and fifth positions of the switch OCS. When the last code switch wiper 200 is earthed in the sixth position of the switch OCS, earth is extended over contacts 254, 255, 256 to the wire 250 to drive the switch OCS through this position into its seventh position. If the wanted exchange requires six routing digits, the operation is the same as for five digits with the exception that in its final position the last wiper 200 of the code switch rests upon a contact which, instead of being connected to the skip wire 250, is connected in the usual manner over the jumpering frame IDF to a stop conductor, in order that a sixth routing digit will be sent in the sixth position of the control switch OCS. Transmission of the numerical digits. In the seventh position of the outgoing control switch OCS, tne interrupter contact 139 of the register M4 is included in the loop across the impulsing wires 91, 92, and a circuit is closed over earthed wiper 304 for relay 319, which associates the relays 308, 312 with the registers M1 - - M4. Earth from the wiper 181 of register M4 is also extended over wire 182 and wi