GB600267A - Improvements in contact selecting fingers for cross-bar switches - Google Patents

Abstract

600,267. Automatic exchange switches. TELEFONAKTIEBOLAGET L. M. ERICSSON. March 12, 1945, No. 6191. Convention date, March 13, 1944. [Class 40 (iv)] In a cross-bar switch in which alternative spring groups can be selected by a vertical selecting bar through a selecting finger, the selecting finger is non-flexible and separate from the selecting bar and can only be actuated by the selecting bar when the corresponding operating bar is in its normal retracted position. As shown in plan in Fig. 3, the selecting finger 21 is mounted on a vertical pivot 23 in a frame 22 and has a U-shaped extension which may engage around the tongue 17 on the vertically pivoted selecting bar 11, this being capable of being tilted to one side or the other by magnets 15, 16, so as to set the finger under either of the spring sets 31 for actuation by magnet 18 through the horizontal operating bar 12. This action raises the outer end of the finger 21 clear of the tongue 17 so that the selecting bar has no further effect. When the magnets are de-energized the finger returns to its central position and re-engages the tongue 17 for further actuation.