GB758949A - Improvements in or relating to relay selectors and cross-bar switches - Google Patents

Abstract

758,949. Automatic exchange switches. TELEFONAKTIEBOLAGET L. M. ERICSSON. Feb. 1, 1954 [March 4, 1953], No. 2992/54. Class 40 (4). In a cross-bar switch or a relay selector the conductors of the bore-wire multiple are located in grooves in one face of a block of insulating material and the contact springs pass from the opposite face through holes in the block, which holes are crossed by the grooves. As shown, in the selecting bar unit of Fig. 2 the contact springs 18, having cylindrical silver contacts 18a, pass through holes in the block 2, which block 2 has longitudinal grooves in which the bore-wire multiple conductors 2a (Fig. 5) are located. These grooves cross the holes 2b. To operate the cross-bar switch the selecting magnet 17b, corresponding to the spring set shown in Fig. 2, is operated, whereupon the selecting bar 14 moves downwards, thus rotating the indicating means 15 in a counter-clockwise direction so that the lug 15a contacts the operating bar 6. Operation of the operating magnet then rotates the operating bar clockwise, so lifting the indicating device 15, which in turn lifts the lifting bar 16. The springs 18 are thus raised so that the contacts 18a engage the conductors 2a. Release of the selecting magnet restores the selecting bar which can then be reoperated without moving the operated indicating device. Release of the operating bar restores the lifting bar and the contact springs to normal. The bend in each of the conductors 2a at each hole which it crosses is formed after the conductors have been laid in the grooves and serves to provide two points of contact with each spring contact 18a instead of the usual one. A multiple relay (Figs. 6, 7, not shown), is also described in which the holes are vertical slots crossed by the conductors, each slot serving for the passage of all the springs of a spring set.