Patent ID: 7694368

Claim:
A height adjustable ambulance cot comprising: an upper frame providing at least one channeled support member having a plurality of holes, said at least one channeled support member having inner surfaces which comprise an upper track portion and a lower track portion; a support mechanism configured to height adjust said upper frame; a traverse frame member pivotably connected to the support mechanism; at least one latching trolley configured for movement about said at least one channeled support member, said at least one latching trolley being connected to said traverse frame member, said at least one latching trolley comprising upper and lower rollers, wherein in a weighted position, said upper rollers engage said upper track portion, and in an unweighted position, said lower rollers engage a lower track portion of said at least one channeled support member; and a positive lock having at least one locking pin configured to be held releaseably in said plurality of holes via an interference fit in said weighted position, wherein said interference fit is cleared by lifting said upper frame to said unweighted position, thereby permitting said at least one locking pin to be released from an engaged one of said plurality of holes.