GB252057A - Improvements in automatic telephone switching apparatus - Google Patents

Abstract

252,057. Standard Telephones & Cables, Ltd., (Deakin, G., and Schreiber, L. J. J.). Feb. 11, 1925. Selectors.-In a rotary switch comprising two movable parts, for example. a brush carriage and a trip spindle, both movable parts are driven from a common continuously-rotating shaft through flexible gear wheels normally warped out of engagement with continuously rotating gear wheels on the shaft. The brush carriage 3 is mounted on self-centring bearings 9, 10 and is driven from a common shaft 11 through gear wheels 12, 13. The gear wheel 13, which is flexible is normally warped out of engagement with the gear wheel 12 by a spring-urged arm 15, as described ni Specification 201,256, but on the energization of clutch magnet 14. the arm 15 is retracted, the wheels 12, 13 engage, and the carriage is rotated. An extension of the brush carriage spindle 3 carries two gear wheels 22, 23, rigidly fixed with respect to one another, but freely rotatable on the spindle 3. The wheel 23 is normally warped out of engagement with another gear wheel on the shaft 11 by an arm 25 controlled by a clutch magnet 24. When these gears are in mesh the trip spindle 4 is rotated through the gear wheels 22, 21. The trip spindle 4 is mounted on self-centring bearings 19, 20, the arms which clamp these bearings to the bearing surfaces on the frame being slightly adjustable to permit any back-lash to be taken up. A roller 16 is provided for resetting the brushes 1 when the brush carriage is returned to normal. The common shaft 11 may be situated in any position which is most accessible. Specifications 194,878, 226,923 and 249,640 also are referred to.