Abstract: A reversible drive device rotates a sprocket wheel so that an endless chain engaging said sprocket wheel moves through a vertical path and then in a semicircular path around a chain guide. A workpiece conveyed by a conveyor device from a preceding stage is clamped by a clamping device extending from a base end of a workpiece retaining arm having an outer end connected to said chain. If the workpiece is to be transferred in an inverted orientation, a slider pivotally supporting the base end of the workpiece retaining arm is raised along a slide guide by the chain; then the outer end of the workpiece retaining arm circles around the upper end of the chain guide together with the chain, thereby rotating the workpiece retaining arm by half a turn and inverting the workpiece.