GB359431A - Improvements in or relating to quick make and break electric switches - Google Patents

Abstract

359,431. Snapaction switches; drum controllers. T. S. MOTORS, Ltd. and DINE, E. H., Victoria Works, Maidstone, Kent. July 16, 1930, No. 21519. [Classes 38 (iii) and 38 (v).] Contacts.-As the contact arm of a switch comes to the end of its throw it is pressed against one part of a lever mechanism through which the contacting surfaces are pressed into contact with a considerably increased pressure. A drum controller 1 operates through a lost-motion device 20 to push or pull a connecting-rod 2 to cause a contact 4 on an arm 3 to engage either the contact 6, or the contact 6a of a change-over switch. A link 15 is pivoted at one end to the pivot 5 of the contact-arm 3, and is connected at the other end 14 to a link 13. A tension spring 10 connects the end of the link 13 to the contact-arm 3. The connecting-rod 2 is connected at 14 to the junction of links 13, 15 so that on moving the rod to the right the spring 10 is carried past the dead-centre position moving the contact-arm 3 across to engage the contact 6a. Projections 16 on the link 13 co-operate with the forked end 17 of the rod 2 to assist in throwing over the spring. The contact 6 is mounted on the shorter limb of a pivoted bell-crank lever 7 and is pressed downwards by a leaf spring 9. When the moving contact 4 first comes into contact with the contact 6 the latter is raised until a projection 8 on the lever 7 meets the contact-arm 3 and further movement serves to increase the contact pressure.