Vehicle door operating mechanism

A sliding door operating mechanism for a vehicle to provide access to said vehicle through an opening (8) in a wall (9) thereof, including a beam structure (15) carrying door means (6, 7), power means (32, 33) and transmission means (35, 36, 37, 40, 41, 42) for transmitting movement of said power means to said door means for performing opening, closing and locking movements thereof, said beam structure extending across and being accommodated within an upper portion of said opening (8) so as to be slidingly movably driven by said power means (32, 33) between a relatively retracted position within said opening (8), in which said door means (6, 7) is located in a first plane in a closed position confined within said opening, and a relatively less retracted position, in which said door means is located in a second plane exteriorly of said opening allowing movement of said door means along said second plane, characterized i n that said power means includes two members (32, 33) relatively movable upon actuation of said power means, a first (32) of said members movably connected to said beam structure (15), and a second (33) of said members movable a predetermined travel relative to said first member (32) and being connected to said transmission means (35) so as to impart closing movement to said door means (6, 7) during a major part of said travel, in which said door means is located in said second plane, and to be prevented from further movement when said door means is in its closed position, said first member (32) being connected to said beam structure (15) such that further actuation of said power means moves said beam structure laterally towards its relatively retracted position.