Automatic grounding connection for electrical unit

Claim 1

For an electrical unit such as a wall receptacle which has a metal mounting strap for attaching the unit to a metal flush box, apparatus for making electrical connection between the mounting screw and the strap, comprising: a resilient tab of electrically conductive material separate from the metal strap and located under the metal strap having an opening defined by inwardly extending resilient fingers for receiving a threaded member; said tab being bent so at least one edge curves upward toward the strap, the mounting screw passing through the strap and threadably engaging said resilient fingers and biasing said fingers in the direction of advance of the screw so that as the screw is threaded into the box the tab is drawn upward to make pressing low resistance electrical contact with the strap, the shank of said mounting screw containing a circumferential unthreaded relief section just below the screw head somewhat deeper than to the minor diameter of the threaded section whereby when the screw is threaded through the opening in the tab beyond the end of the threads, the fingers come to rest in the relief section while still making electrical contact with the screw.