Patent ID: 8069954

Claim:
A lift comprising: a first chain, formed of first links with a first surface, and a second surface, said second surface facing oppositely said first surface, said first links that pivot relative to one another, said first links have first interlocking surfaces on said first surface, wherein said first interlocking surfaces have curved surface portions, and have third interlocking surfaces on said second surface opposite said first surface, wherein said third interlocking surfaces have a curved surface portion, and said second surface is symmetrical to said first surface; a second chain, formed of second links with a first surface, and a second surface, said second surface facing oppositely said first surface, said first links that pivot relative to one another and have second interlocking surfaces thereon on said first surface, where said second interlocking surfaces have a curved surface portion, and have fourth interlocking surfaces on said second surface opposite said first surface, wherein said fourth interlocking surfaces have a curved surface portion, and said second surface is symmetrical to said first surface, and where curved surfaces of said second links mate to concave portions of said first interlocking surfaces of said first links on both first and second surfaces of said first links, and when mated, hold said first chain to extend in a straight line, and hold said second chain to extend in said straight line interlocked to said first chain, and when mated, prevent said first and second links from pivoting relative to one another; a housing, holding said first and second chains; a moving part, coupled to said housing, to extend and retract said first and second chains, said first and second chains forming a lift that extends above said housing when extended, wherein said first and second links include a first portion that includes said interlocking surfaces, a first pivot on a side of said first surface, a first leg, attached to said first pivot and said first portion, a second pivot on side of the second surface, a second leg, attached between said second pivot and said first portion, and said first and second legs having surfaces facing one another which define an open area between said first and second legs, and wherein said open area between said first and second legs is substantially polygonal in shape.