GB752902A - Improvements in or relating to crossbar switches - Google Patents

Abstract

752,902. Automatic exchange switches. TELEFONAKTIEBOLAGET L. M. ERICSSON. Feb. 12, 1954 [Feb. 14, 1953], No. 4278/54. Class 40 (4). In a cross-bar switch a selecting bar unit (Figs. 2, 3) comprises two groups of vertical conductors 19, one group on each side of the metal sheet 11, each group having contact springs 18 with cylindrical silver contacts 18a. Each group 19 has an associated selecting bar 14 and an electromagnet 17a or 17b. Each set of contact springs may be raised by a lifting bar 16 individual to the set, each bar having an extension 16a (Fig. 3) on which an indicating means 15 is mounted so as to be free to rotate. Springs 21 urge the indicating means 15 anticlockwise but they are normally held in the position shown in Fig. 2 by engagement of the flaps 15c against shoulders provided on the respective selecting bars 14. The tongue 11a on the metal sheet 11 serves to locate the operating bar units 2 (Figs. 1, 2) with respect to the contact springs 18, the contacts 18a entering holes in the units 2. Operation of a selecting magnet 17a or 17b moves the corresponding selecting bar 14 downwards, whereupon the relevant indicating means 15 rotates under the action of the corresponding spring 21, the flap 15a being thus pressed against the operating bar 6. On operation of the operating magnet 5 (Fig. 1), the operating bar 6 then lifts the indicating means 15 which in turn lifts the lifting bar 16 to bring the contacts 18a into contact with the horizontal conductors 2a. On the release of the selecting magnet the selecting bar 14 is restored to the position shown in Fig. 2, and can thereafter be raised and lowered without affecting the raised indicating means 15. The release of the operating magnet 5 effects restoration of the operating bar 6 and lifting bar 16.