Patent ID: 8128307

Claim:
A structure comprising: a first plate comprising a first opening; a second plate comprising a round opening and a notch, said notch being in a second end of said second plate and said round opening being adjacent to said notch, said second plate being connected to a first end of said first plate; and a locking structure within said first opening, said notch and said round opening, said locking structure connecting said first plate to said second plate, said locking structure comprising a threaded member and a threaded insert, said threaded insert comprising a threaded opening having threads corresponding to threads on said threaded member and a post adjacent to said threaded opening, said threaded member being positioned on said notch and further extending from said notch into and fitting screwably within said threaded opening and said post extending from said threaded insert through said round opening such that said post is parallel to said threaded member; said threaded insert further comprising an exterior surface and at least two exterior slots in said exterior surface, said first opening comprising two continuous rectangular openings, a first rectangular opening of said rectangular openings being larger than a second rectangular opening of said rectangular openings, said second rectangular opening being positioned closer to said first end of said first plate than said first rectangular opening, said first rectangular opening having a size larger than said exterior surface of said threaded insert, and said second rectangular opening having a size smaller than said exterior surface of said threaded insert and larger than said exterior slots of said threaded insert such that said second rectangular opening fits within said exterior slots of said threaded insert.