GB286638A - - Google Patents

Abstract

286,638. Associated Telephone & Telegraph Co., (Assignees of Sengebusch, H.). March 7, 1927, [Convention date]. Automatic exchange apparatus.-In a rotary stepping switch an arc-shaped contact bank support is adjustably secured to the switch frame, and a plate carrying a set of relays with their armatures and spring assemblies is detachably connected to the switch frame. A mounting for the armature of the driving magnet, an interlocking device for line and cut-off relays, and forms of wipers and back contacts are also described. An arc-shaped plate 4 to which the contact bank assembly is bolted, is secured :o the switchboard by lugs 48, 49, the switch frame 3 being detachably and adjustably connected to the plate 4 by bolts 10, 11 engaging slots in the plate. The contacts 40 - - 43 of a set are staggered at their outer ends as shown. The wipers 60 - - 63 are double-ended (only one end being shown in Fig. 1), so that when one end is in engagement with the first set of contacts, the other is one step away from the last set. The contact edge of the test wiper is slightly elongated so that it still engages one contact after being advanced to engage the next one. Electrical connection with the wipers is effected through brushes such as 63<1>, Fig. 2. The switch rotates in the same direction during setting and release, and when the wipers reach normal and engage the contacts 23, the circuit of the driving magnet 5 is broken at the springs 64. 65, Fig. 2. actuated by an arm 35 on the wiper shaft. A numbered disc 37 on the wiper shaft indicates the position of the wipers. The armature 6 of the back-stroke driving magnet 5 has a knife edge resting in a V-shaped groove formed by the end of the heel piece 26 the projecting portion of a plate 17 secured thereto, and the tensioning spring 7 is connected to a plate 19 on the armature, and to a member adjustably connected to a plate 17, the, stroke of the armature being adjusted by a screw 9. Lugs 36, 36<1> on the plate 17 prevent lateral movement of the armature 6. A resilient stepping pawl 8 is rigidly secured to the armature 6, which also carries an insulated bush 66 for actuating the interrupter springs 24, the backward stroke of the armature being limited by a stop 22. The line and cut-off relays 51, 50 are mounted on a plate 2 detachablv secured at 15, 16 to the switch frame 3, their armatures being provided with an interlocking device comprising a spring bar 52 bolted at 53 to the plate 2 and formed with a forked end 56, 57. The part 57. adjacent the armature 54 of the line relay, is inclined so that if this relay is energized first, as upon initiation of a call, the interlocking device is displaced so that the part 56 lies clear of the armature 55 of the cut-off relay, which is thus free to pull up. If the cut-off relay is energized first, as in an incoming call, full movement of its armature is prevented by the part 56 to avoid energization of the line relay.