Patent GB-406079-A (GB)
Title: Circuit arrangement for electro-motive driving devices for selecting switches of the kind used in automatic telephone and other remotely controlled selective systems
IPC: H01H63/22
Filed: 1932-10-07
Abstract: 406,079. Automatic exchange switches and apparatus. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Oct. 7, 1932, No. 28018. Convention date, Oct. 7, 1931. Addition to 385,412. [Class 40 (iv).] In an electro-motive driving device, for a selector, of the type described in the parent Specification, step-by-step movement is effected by energizing the field magnets not at the moment energized under the control of the rotor, by (1) auxiliary means under the control of the impulsing relay ; (2) means controlled by the energized field magnet; and (3) an auxiliary armature. Continuous rotation can be slowed to a predetermined speed by the use of an impulse generator. The two field magnets may be separately controlled by the rotor and the impulsing device respectively. The field comprises two magnets and the rotor can have either two or four poles, the field magnets being arranged at 90‹ for a two pole rotor and at 135‹ for a four pole rotor. Construction and general arrangement. As shown in Fig. 1, when contact a pulls up, magnet I and relay A1 energize in parallel. Relay A1 is retarded so that its armature a1 does not make contact until the rotor has passed the midpoint between the two magnet poles. Armature a1 connects the two magnets I and II in parallel. The rotor moves on until it is centred before the magnet pole where it is held until a falls away, de-energizing I, II and A1. The contact DL has changed over so that when a again closes the rotor makes a further quarter revolution and is held in its new position by a1 connecting up both magnets as before. This cycle is repeated with each impulse from a resulting in step-by-step movement of the wiper. In the constructional form shown in Figs. 2 and 3, an auxiliary armature Hi is provided which is loosely connected to the main armature by means of the spring F and is positioned against stop S. When the contact a is closed, magnet I is energized and the armatures move towards the magnet, the auxiliary armature moving first. When Ha reaches a predetermined position between the magnets, Ha1 changes over to energize magnet II, but magnet I is maintained energized over Hi1. The armatures remain in front of magnet I until a is opened when both magnets de-energize, Hi moves forward to its position of rest and changes over contacts HiI and II. As shown in Figs. 4 and 5, the auxiliary springs are closed by the field magnets. Contact u is closed and then, when a is closed, magnet I energizes and closes contact Hi1. The armature moves forward and is held in front of magnet I, contact Ha1 changing over during the rotation to produce the stationary field. Condensers and resistances may be provided for spark quenching purposes. For limiting the speed of movement of a switch the arrangement shown in Fig. 7 is provided. As the contact DL changes over, relay J is energized and de-energized and during the periods taken for energization and de-energization of this relay both magnets are energized to stop the rotor. As an alternative the relay J may be impulsed from a separate interrupter. Embodiments are also described in which the motor makes two steps for each single step movement of the wipers. In these the impulsing contact affects one of the magnets only, the other being controlled by the cam contacts of the motor. If a switch driven by a motor of this type is to search for a free line, the second of the two magnets is arranged to be locked up when a free circuit is reached. Although, as described, the rotors normally have two poles, a rotor with four poles is shown in Fig. 9 with the two magnets arranged at 135‹. The motor moves a complete step for each cycle of the two magnets, moving from the position shown to the position with pole 1 facing magnet I on the energization of magnet I and from this position to the position with pole 2 facing magnet II when magnet II is energized. Group selector. Fig. 14 shows the invention as applied to a group selector. When the selector is seized V energizes, connecting A to the a lead and when the first impulse is received C energizes, in series with the holding winding of V, and locks, over its second winding, for the duration of the call. Both windings of the driving motor MO(i), MO(ii) are now energized over 9c, 22v, 17mo to MO(ii) and 9c, 22u, 17mo, 26c, 27s, 29a, 25s, wiper d in position O, to MO(i). When, after receipt of the first impulse, 29a is opened, MO(i) is deenergized and the motor steps the wipers to position 11 when both magnets are again energized over d and 28a. If 28a is again opened by the receipt of a second impulse MO(ii) is de-energized and the motor runs under control of cam contacts 16mo, 17mo until d reaches contact 10 where both windings are again energized over 29a unless the impulse has terminated. If 29a is open, or if not when it does open, the wipers are moved to position 21 where the motor is stopped over 28a. If another impulse is now received this action is repeated, moving the wipers to position 31. When the train ceases V relapses connecting A to interrupter RU, disconnecting 16mo and 17mo, putting the motor magnets under control of 18a, 19a, and completing the testing circuit through P to the c wiper. The wipers are now stepped stepby-step as A is impulsed from RU and when c finds a free outlet, P energizes, opening the impulsing circuit and the circuit of A and switching through. If no free outlet is found the wipers are stepped to the last terminal of the group, such as terminal 20, in which position both magnets are energized over d and S pulls up over its second winding. V reenergizes in series with winding (i) of S and off normal contact 3w, breaking both the circuit of A and the testing circuit and reconnecting the cam contacts 16mo, 17mo to earth so that the motor runs uninterrupted to contact 101. In this position both motor magnets are again energized over d. P pulls up over its third winding and busy signal is returned, in known manner, to the calling party. When the calling party clears, C falls away disconnecting MO(ii) and the motor steps the switch to its normal position when both motor windings are again connected up over d. Off normal contact 3w opens, releasing S and restoring the apparatus to normal. If a conversation has taken place, when the calling party releases S and V energize over their windings (i) in series and the switch is stepped to its home position, where the apparatus is released as described above. Instead of providing a separate interrupter, the part of the circuit A-RU may be replaced by the circuit shown in Fig. 15, contact 36mo being operated when MO(i) is switched in and opened when MO(ii) is connected up to provide the impulsing circuit for A. Final selector with P.B.X. arrangements. The circuit of a final selector is indicated in Fig. 16. When the selector is seized, C energizes and amongst other functions prepares a locking circuit for itself. On the first impulse being received A energizes and V pulls up, holding up for the remainder of the train. Both motor magnets are energized over 29v until the impulse ceases when 28a opens, releasing MO(ii) and allowing the motor to drive the wipers to position O when the switch is stopped over d and 32a. On receipt of the next impulse, MO(i) is de-energized and the motor, driven over 21mo, 22mo, moves the switch to position 19 when, if A is still energized, both windings again become operative over 28a. If the impulse has terminated, or when it does terminate, 28a opens and 32a closes and the wipers are moved to position 10. A similar action takes place on each impulse of the train so that when the train terminates the wipers are positioned on one of the positions 10, 20 &c. V now falls away and E energizes over its winding (i). On the receipt of the first impulse of the second train, A pulls up and V re-operates completing a circuit for the windings (ii) of both E and U, U locking up for the duration of the call over (i). The operation of U and E brings in the magnet contacts 41mo, 42mo which correspond with Hi(i) and Hi(ii), Fig. 5, and the switch is now stepped step-by-step in a manner similar to that described above in connection with Fig. 5. When the wipers have been fully set, V again falls away and opens the circuits of windings (ii) of E and U so that E releases. The release of V also completes the test circuit to wiper c so that, if the line is free, P operates to stop the switch and extend the call. The switch is released when C falls away on the termination of the call, U falls away and P de-energizes, re-completing the circuit for the motor magnets over 21mo and 22mo. The switch is stepped to position 101 where both magnets are again energized over d and as off normal contact 12w now opens, V releases to restore the apparatus to normal. Called line busy. If the called line is busy, V releases as before but P will not operate. E falls away, M operates and busy tone is returned in the usual way. When the calling subscriber clears the apparatus is released as before described. P.B.X. hunting. If a subscriber has more than one line, the contacts wiped by d are connected as shewn by x, y, z. When the wipers have been set the switch stands with wiper d connecting with x. If the line is busy relay P does not energize over c and, after the slow period of E, M pulls up. E is thus re-energized over d, opening the circuit of M and connecting up the motor contacts 21mo, 22mo, and 41mo and 42mo, so that the wipers are moved into the next position. When M, which is made slow to release by its shorted winding (i), releases the line is tested and, if free, P switches through. If this line happens to be busy however, E, which released when M fell away, is again operated and the wipers are again stepped forward. This cycle is repeated until either a free line is found or the last line of the group is reached. The last line r of a testing group, e.g., lines 19, 29, 39, &c., may be added to a P.B.X. group by prov