Method of and apparatus for transferring and positioning pallet

摘要

A pallet with a workpiece mounted thereon is delivered on a pallet carriage, and transferred onto the table of a machine tool which has a different height from the pallet carriage. Lifting mechanisms on the pallet carriage are engaged by respective positioning members in front of the machine tool. The lifting mechanisms are actuated to lift the pallet carriage to position the pallet carriage for transfer of the pallet onto the machine tool table. The pallet is transferred from the pallet carriage onto the machine tool table, half of a predetermined stroke by a first transfer mechanism on the pallet carriage and the remaining half of the stroke by a second transfer mechanism on the machine tool table. The table has vertically movable support rollers for supporting the pallet when it is transferred onto and from the table. When the pallet P is positioned on the table, the vertically movable support rollers are retracted downwardly. When the pallet is transferred onto the machine tool table, clamp units on the machine tool table enter T-shaped slots defined in the lower surface of the pallet, and are actuated to clamp the pallet directly on the table. Since the workpiece on the pallet thus clamped is held in a low position on the machine tool table, the workpiece can be machined by a machining tool that can move freely in a wide space.