Abstract: A lock nut device consists of a lock nut (22) and a lock spring (31). The spring is bent into an U-shape and extends in a axial plane over the nut. It has spring legs (32) lying in grooves (25) in the nut and has end portions formed for engagement with the profile portion (16) on a non-rotatable element (4). In the engagement position, the legs are at such a distance from the nut surface that, with the aid of a socket forced over the nut, they can be pressed towards the nut surface, thus moving the end portion from the engagement position.

Abstract: An anti-rotation locking assembly for releasably fastening automotive exhaust pipes and exhaust manifolds to an engine block is disclosed comprising a threaded bolt with hex-wrenching recess and a hyperbolic locking plate with hex-stud which fits into the wrenching recess of the bolt and is attached thereto by cotter pin or Q clip. The locking plate has a contour which mates with said exhaust pipe and thereby prevents the bolt from working loose due to vibration of the engine.

Abstract: Locking fastener comprising a threaded part such as a bolt or nut and a lock plate which fits over the bolt or nut and is prevented from rotation by engagement with a stationary object such as a protrusion on the part to be secured. The lock plate has an opening with a contour which mates with the outer contour of the threaded part to prevent rotation of the threaded part, and the plate is retained on the threaded part by a retainer received in a detent opening or groove formed in the threaded part. In some embodiments, the retainer is a separate part which is free to rotate in the groove. In other embodiments, the retainer comprises a detent lug carried by the lock plate.