Patent ID: 7891904
Filing Date: 2011-02-22
Classification: E02D

Abstract:
1. A mechanism for preventing a cover received in an opening in a surrounding structure from being completely removed from said surrounding structure, comprising: a holder body attached to an underside of said cover; said holder body formed with a passage extending into said body and slidably receiving a stop member so as to be able to be moved in said passage therein between a retracted position and an extended position with one end protruding out from said body and into alignment with a fixed abutment formed on said surrounding structure to prevent said cover from being completely free of said surrounding structure; a drive member having a threaded main portion received into a threaded bore in said holder body extending into said passage and having a tip able to be advanced into engagement with a downwardly angled surface formed on said stop member; said stop member surface aligned with an axis of said drive member; whereby as said drive member is advanced in said threaded bore, said stop member is cammed to said extended position.