Patent GB-171423-A (GB)
Title: Improvements in selecting devices for automatic telephone systems
IPC: H01H63/00
Filed: 1920-05-18
Abstract: 171,423. Siemens Bros. & Co., Ltd., Petithory, E. A., and Collyer, J. E. May 18, 1920. Selectors. - The wiper sets of a number of automatic telephone selectors can be clutched to a common operating-spindle, the arrangement being such that after the wipers of one selector have been adjusted, the spindle can be restored and then operated again to adjust the wipers of another selector. In the construction shown in Figs. 1, 2, and 3, the wipers of the several selectors are carried by loose sleeves 15 surrounding a spindle 6, which is raised and rotated by the vertical and rotary ratchets A, B. In building up a connection, the magnet 17 of a wiper set is energized, and engages the rod 8 above the collar 10 by a fork 19. At the same time the magnet 24 is energized, withdrawing the pin 36 from the retaining-sector 21, and allowing the wiper set to rise with the spindle 6 in response to the vertical impulses. At the first rotary impulse, the magnet 24 is deenergized and the teeth in the retaining-sector 21 engage the plate 25 on the armature 26 as the sector is carried round the wipers against the action of the spring 30. The casing 29 of the spring carries two lugs 32, 34, the former engaging in the rest position a pin 33 on the retaining- sector, while the second engages the teeth of the plate 22 holding the spring against rotation during the rotary stepping. When the desired connection is effected the magnet 17 is de-energized, declutching the wiper set from the operating- spindle, which rotates back and drops to its normal position ready to operate other wiper sets. The operated wiper set is supported by engagement of the retaining-sector 21 with the teeth in the plate 22. On release of the connection, the magnet 24 is energized and the plate 25 withdrawn from the teeth in the sector 21. Rotation of the wiper, under the action of the spring 30, brings the notch 37 opposite the teeth of the plate 22 and the set falls to its lowest normal position, where it is supported by the projection 28. In the construction shown in Figs. 5 and 6, the selectors are power-driven switches with movement in a vertical direction only. When the wiper set 70 is taken into use, its magnet 56 is energized to latch it to the common spindle 45, which carries " tens " and " units " testing wipers 61, 63. The " tens " wiper 61 engages terminals spaced ten units apart, and when this wiper reaches a terminal to which marking potential has been applied by an auxiliary switch set by ' tens impulses, a circuit is closed for tripping the " units " wiper 63 into engagement with the spindle. The wiper 63 engages ten terminals spaced one unit apart, and when it reaches the terminal, to which marking potential has been applied by an auxiliary switch set by " units " impulses, it closes a circuit to trip the wiper set 70 of the selector out of engagement with the spindle 45. The wiper set is held in position by engagement of the projection 59 with a notch of the plate 60. On termination of the conversation the magnet 56 is energized, causing the wiper set 70 to be again clutched to the spindle when the notch 58 next comes opposite the projection 59, and to be returned to its normal position. In case all the selectors operated by the spindle should be busy at the same time, the magnet 66 is provided to retain the spindle in its extreme vertical position until one of them is released. The bank contacts may be extended as shown on the right of the frame 38, Fig. 5, and a second operating-spindle provided.