GB216327A - Electric relay for telephone systems - Google Patents

Abstract

216,327. Coventry Automatic Telephones, Ltd., and Collyer, J. E. May 16, 1923. Electromagnetic relays.-In the magnetic circuit of a relay adapted for use in automatic telephone systems and comprising a core 2, a yoke 4, an adjustable yoke extension 8, and an armature 7, the armature is so suspended from the yoke extension as to provide between n them an air gap of relatively small width but large area, thus forming a joint of low reluctance, and the adjustment of the yoke extension is such as not to effect appreciably the reluctance of the circuit. The armature 7 is pivoted to the extension 8 by a pin 9 of non-magnetic material with the interposition of thin brass washers 10, 11, Figs. 2 and 3, and the extension is bent as shown at 8<a>, Fig. 1, to present a large surface to the armature. The extension 8 is of a cross-sectional area approximately equal to that of the yoke 4 and for adjustment purposes is provided with elongated slots through which pass screws 23, 24 engaging tapped holes in the yoke 4.