GB228269A - Improvements in electrical switching apparatus particularly for automatic and semi-automatic telephone systems - Google Patents

Abstract

228,269. Relay Automatic Telephone Co., Ltd., and Shklovsky, G. E. Nov. 1, 1923. Selectors.-In a cross-bar switch, the vertical members are movable along their axes as well as rotatable about them, and are thus able to select one set of contacts in each of a number of groups of four sets associated with them. One of the selected sets is then closed by the operation of a particular horizontal member and is held after the vertical members are released. In the switch described, the contacts controlled by a particular horizontal member are arranged in two levels H', H<2>, Fig. 1, and are carried by a plate P forming part of the magnetic circuit of the operating magnet R, C. The horizontal member E, which is formed with a ridge R and carries pieces T, IL, is an extension of the armature A, and is pivoted nn a knife edge on the plate P. To select a contact, one of the vertical bars M. Figs. 4 and 5, is rocked by its magnet RM<1> or RM<2>, and may or may not be previously lifted by its magnet LM. As a result, resilient pieces W<1> or W<2> of piano wire &c. are moved under a set of contacts in each of the groups of four. If the rod M is first lifted, the pieces W<2> are prevented from moving, when the rod is rocked, by shields S<2> on false springs F<2> associated with the lower levels of contacts; otherwise, the pieces W<1> are similarly restrained by shields S<1> on the pieces IL, T. Operation of one of the magnets RC now closes the contacts under which the piece W<1> or W<2> is positioned by means of the pieces IL, T, or the ridge R. According to the Provisional Specification, the vertical rods may have movement only in the direction of their length, the pieces W<1>, W<2> being moved electromagnetically, and the horizontal bars may be coupled together in twos or threes.