GB115275A - - Google Patents

Abstract

115,275. Donovan, W., and Donovan, G. O. May 4, 1917. Plug couplings combined with electric switches. The detachable plug part a of a plug-and-socket coupling is provided with an axial switch-operating member h, i extending through the plug member. When the plug member is in place, the pin h passes into a central hole o in the socket-holder l at the back of which the movable contact - carrying member w of the switch is located. A sleeve q having inwardly - projecting pins is loosely mounted in a recess in the socket-holder; one of these pins is engaged loosely by a slot u, Fig. 4, in the operating-member h and the other pins loosely engage slots in the outer end of the spindle p carrying the member w. Contacts x are mounted on the member w, which is in the form of a disk, and co-operate with contacts fixed above and below them. A quick-break action is produced by a metal cam piece 3 mounted on the member w, and in electrical connexion with the spindle p, co-operating with leaf springs 2, the lost-motion connexion between the operating-member and the switching-member allowing of this action. When the switch is turned to the ' on ' position by means of the handle i, a face on the operating- member h formed by a groove cut therein is engaged by a pin w thereby locking the plug to the socket part when the switch is in the closed position. The operating-handle is earthed by its connexion with the earthed casing m, 11 through the pins 8, the plate 7, the springs 2, the cam 3, the spindle p, the sleeve q, to the operating- spindle h. To ensure that the loose sleeve maintains effective contact with the spindle elements, the sleeve q is pressed laterally by the spring 5 into engagement with these elements. The plug casing also may be earthed by an earthing lead connected to a socket c mounted in the insulating-block b which carries the plugs and is connected with the plug casing by a screw g. The plug part is held to the socket part by a flanged ring 17 and a water-tight union is obtained by means of a rubber disk 20 and a rubber ring 19. One of the plug contacts may be larger than the other to ensure correct insertion of the plug member.