Patent GB-262513-A (GB)
Abstract: 262,513. Automatic Telephone Manufacturing Co., Ltd., (Automatic Electric Co.). Sept. 9, 1925. Automatic exchange systems and selectors. - In a two directional selector which requires only a single magnet for effecting the vertical, rotary, and release movements, the wipers first move vertically downwards under gravity to a level determined by the setting of a helically-stepped rotary member set bv impulses, and the wiper sha.ft and rotary member then become coupled together so that further opration of the magnet causes the wipers to rotate. During release, the rotary member is further advanced in the same direction, the wipers making a complete revolution each time the switch is used, whilst the restoration in the vertical direction is effected at the same time owing to a projection on the switch shaft engaging with a helical runway. Current is fed to the wipers over auxiliary wipers which take part in the vertical movement. Construction. A projection 3 on a cam 2 secured to the wiper shaft 1 normally rests in a small depression at the top of a stepped barrel 7. Intermittent operation of magnet 29 steps round the barrel 7, causing the shaft 1 to drop, and at the end of a series of impulses, projection 3 falls into a tooth 8 of the barrel so that further operation of magnet 29 rotates the barrel and wiper shaft together. The shaft 1 is guided in its vertical movement by a groove at the end of a lever 16 engaging a roller 20 pivoted to the main frame and controlled by a spring 23. At the termination of conversation, magnet 29 is further intermittently energized to step the shaft and barrel together until lever 16 strikes the helical runway 64. The projection 3 is then lifted clear of the teeth 8 and the barrel rotates alone until the projection 3 is engaged by the vertical face of the barrel when the wipers are further advanced and at the same time raised. Just before the normal position is reached, a pin 45 tilts a pivoted lever 14. During the vertical and rotary setting of the wipers, an arm 12, loosely mounted on the shaft and connected to the barrel 7 through a spring 11 was held against movement by a stop 13 on the lever 14, but the tilting of the latter during the restoring operation causes arm 12 to move round and by engaging a pin 17 on the lever 16 causes the wipers to return to their normal position, the projection 3 moving along the horizontal top edge of the barrel. The arm 12 is secured in a readilydetachable manner by means of semi-circular washers 67, Fig. 4, engaging a groove 66 and by a screw cap 69. A cam 36 on the barrel 7 controls off-normal springs 37, and self-interrupting springs for the magnet 29 are also provided. Current is supplied to the wipers 25 - - 27 bv auxiliary wipers 51, 53 mounted on a second shaft 47 which is caused to move vertically with the main shaft by means of a clamp 55 which has a forked end engaging with a groove in the wiper holder 57. Mounting. Circular bars 71 are secured to main supporting memhers 72, 73 by clamps 74 and 75 and the switch frame 5 is fitted to the bars 71 and is secured by nuts engaging the reduced upper portions of the bars. Circuit arrangements. Fig. 10 shows circuit arrangements for a group selector constructed in accordance with the invention. Impulses are repeated by relay 20 over the upper winding of relay 40 to stepping magnet 60 to control the vertical motion, the first impulse passing over springs 70 and the remainder over contacts 42. At the end of the digit, relay 50 is locked up and, on the relapse of relay 40, a circuit is completed for magnet 60 over contacts 52, 41. Rotary motion of the barrel 7 and wipers will now take place in the usual manner under the interaction of relay 50 and magnet 60, and when an idle trunk is found, relay 10 energizes and switches through. At the end of conversation, the release of relay 10 completes a circuit 13, 21, 33, 71 for both windings of relay 40 in series. Relay 40 energizes relay 50 which in turn operates magnet 60 over contacts 52, 32. Further rotary motion thus takes place under the interaction of relay 50 and magnet 60 until the normal position is reached and contacts 72 are opened.