Patent ID: 7455474

Claim:
A cover locking device comprising: a cover, a frame, at least one fastening screw inserted through a perforation in the cover and wherein the screw has a threaded part anchored to the frame and a head sunk into a housing emerging from the cover while resting against a flat surface at the bottom of the housing in order to jam the cover onto the frame by tightening the screw, a waterproof washer made of an elastomer, and an anti-rotational washer interposed successively between the flat surface and the screw head, wherein the anti-rotational washer is provided with at least one means of abutting internal parts of the housing to prevent a rotation of the anti-rotational washer during tightening of the at least one fastening screw and strain hardening of the waterproof washer located under the anti-rotational washer.