Conveying plant

A conveying plant for work-pieces to be processed or assembled one after another at different working positions comprising a guide rail extending longitudinally at said working positions, a push-in device arranged at one end of the guide rail and a push-out device at the other end thereof, a conveying rail arranged parallel with and adjacent to the guide rail, a plurality of dogs provided at the conveying rail at equal interspaces, a drive unit operatively connected to the conveying rail and moving the conveying rail along a continuously repeated substantially rectangular moving path consisting of a working stroke in longitudinal direction of the guide rail, a disengaging stroke, a return stroke parallel to the working stroke and a re-engaging stroke, a plurality of work-piece carriers guided at the guide rail and carrying at least one work-piece respectively, said plurality of work-piece carriers adapted to be simultaneously engaged by said dogs in a form-fit way and to be shifted forward during the working stroke of the conveying rail, and a plurality of clamping devices provided at said working positions respectively and operatively connected with drive means to simultaneously clamp the plurality of work-piece carriers at the guide rail during at least a portion of the rectangular moving path excluding said working stroke, said guide rail having a pair of opposed side walls spaced from one another by a distance substantially equal to the width of the work-piece carriers, a first one of said pair of walls having an inclined inner contact surface at the upper end thereof and each work-piece carrier having a complementary inclined side face and wherein the plurality of clamping devices are arranged on the side of the other one of the pair of side walls and during operation thereof urging the work-piece carriers into clamping contact with the first one of said pair of side walls, each one of the plurality of clamping devices comprising a slider having a tapered end which, in a clamping position, engages an opening of complementary shape of the work-piece carrier, and during movement of the slider into that clamping position, the slider is displaced toward the carrier and comes into engagement with the opening of complementary shape, whereby, firstly the carrier is adjusted in longitudinal direction of the guide rail and secondly the carrier is clamped.