GB702053A - Improvements relating to interlocking electric switches and plug-and-socket connectors - Google Patents

Abstract

702,053. Two-part, couplings combined with switches. PARSONS, Md., C. H., and HANDLEY, G. B. Nov. 12, 1951 [Aug. 25, 1950], No. 21021/50. Class 38 (1) An interlocking switch and plug and socket connector comprises a pawl 25 pivoted at 27 in a slot 24 in an earthing pin socket contact 15 and having a tail 29 urged bv an arm 30 of a torsion spring 31 whereby a nose 28 on the pawl grips the earthing pin 26 and prevents removal of the plug when the switch is "on." A bell crank lever 35 pivoted at 34 has an arm which enters the slot 24 to engage the pawl tail 29, a lug 36 on the other arm of the lever 35 being engageable by a member 37 reciprocably slidable on a projection 38 upon movement of the switch dolly 12, the projection 38 being formed on a bridge piece 16 carrying the dolly 12. When the dolly is moved to the "off" position, Figs. 1, 6, the lug 36 is engaged by the member 37 and the pawl 25 moved by the lever 35 to withdraw the pawl nose 28 and permit removal of the plug. To prevent closure of the switch when the plug is removed a slide 39 biassed by a spring 41 on a plate 19 has a nose 44 extending through a slot 45 in the socket contact 15 and pivotally supports an arm 47 connected to the member 37. When the plug is removed the spring 41 moves the slide 39 so that nose 44 enters the slot 45 and a lug 48 on the arm 47 moves opposite to the bridge piece 16 thus preventing movement of the member 37 by the dolly 12. The contact 15 has a screw-threaded tail passing through openings in the plate 19 and base 10, whereby the parts are clamped together by a nut, the live contacts 14 being mounted on a raised part 17 of the base 10 remote from the fixed and moving switch contacts .11, 13. Specification 522,147 is referred to.