Abstract: A work transfer assembly including a transfer car movable along a path for transporting a workpiece carrier between separate processing stations positioned along the path. The car includes a push-pull chain made up of a plurality of links with one of the links defined by a pair of spaced support plates having upwardly extending support flanges interconnected by a shaft which rotatably supports a coupler member. The coupler member is a single unitary member having a pair of side plates interconnected by an abutment plate below which is an L-shaped plate defining a hook. The coupler member is rotatably supported for movement between a hook position with the hook in position for hooking a tray for removing the tray from a station and an abutment position with the abutment plate in position for abutting the tray for pushing the tray into the station.