GB205062A - Improvements in switching apparatus for telephone exchange systems - Google Patents

Abstract

205,062. McBerty, F. R. Oct. 6, 1922, [Convention date]. Automatic exchange apparatus; selectors.- -The wipers of selector in which the rotary precedes the vertical movement are relieved of the pressure of the returning spring while they are in engagement with the bank terminals. The wiper carriage may be disengaged from the, operating mechanism to allow of inspection of the wipers and the operating mechanism is arranged so that during the rotary movement the vertical mechanism is not moved and vice versa. As shown, Fig. 1, the speech and test terminals are arranged in a single bank, the two sets being separated by a metal sector 51 into which are screwed the bolts holding the bank together. The wiper carriage 3 is of insulating material and mounted on a fixed rod 4 and engages the rotary ratchet 17 by means of pins 25 and slots 26, Fig. 3. An arm 38 carried by the vertical ratchet 32 carries a pin 39 which works in a groove 40 surrounding the carriage. The magnet 11 drives the ratchet 17 against a spring 27 which is arranged inside the ratchet. Stops 22, 23 are so arranged that the armature 15 and pawl 16 respectively reach them simultaneously, to minimize wear of pawl 16. The armature-returning spring 19 is adjusted by means of a screw 21 the pitch of which is greater than that of the spring, the inside of which it engages. The ratchet 32 is operated by magnet 12 through a pawl 31. At the first vertical step the slots 26 leave the pins 25 so that the wipers are relieved of the pressure of the returning spring. Vertical release is effected by magnet 13 which disengages detent 36 and pawl 31 and allows the wiper carriage to drop to its lowest position, in which it is in engagement with the rotary ratchet, after which, e.g. by means of vertical off-normal springs 44, magnet 14 is operated and releases the rotary ratchet. The supporting frame 1 is stamped from sheet metal, the supporting members 8 - - 10 being integral with it, and most of the other parts are also stamped from sheet metal. The insulating parts are machined from hard rubber, a phenolic condensation substance &c.