GB534668A - Improvements relating to electric switches and contacts therefor - Google Patents

Abstract

534,668. Snap-action switches; contacts. STANTON, H. B. Sept. 12, 1939, No. 25635. [Class 38 (v)] Fixed contacts i, j, adapted to be cramped into engagement with the hooked ends of movable blades e on a shaft f, are assembled on a shaft k with spacers o, the arrangement being such that when the blades e come into place, a wedging action is exerted between an adjustable cam s and the shaft k whereby the cramping is effected. The wedging is effected by the end v of an arm u fast on the handle spindle f<2>, a curved link z being connected to the arm u at 18 and to a dead-centre spring 16 to maintain the arm u in its clamping position. Adjacent pairs of contacts i, j are adapted to be connected together by adjacent pairs of blades e which are in a single U-shaped piece, the blades engaging the contacts i being directly in contact with the end contacts 19 of fuses 20. The remote fuse contacts 22 are each arranged to engage between similar contacts 21 on a further shaft 26 which is rotatable by means of a hand lever 28 and is threaded into the box wall so as to be capable of unclamping the contacts 22. A lost-motion device permitting 180 degrees rotation of the handle comprises lugs w, x on the arm u co-operating with a lug y on a freely-rotatable plate z, lugs 10, 11 on the latter co-operating in turn with a lug 12 on shaft f. The shaft f is finally moved by a deadcentre spring link 13, 14, pivoted to the plate z at 15.