Combination machine tool apparatus and pallet changing system

Abstract

Combination machine tool apparatus and pallet changing system includes a single changer for changing both work pieces at a work piece machining station on the machine tool and tools at a tool storage station on the machine tool. The work piece machining station and tool storage station are offset approximately 45.degree. from each other as measured from the rotational axis of the pallet changer, which is provided with additional retractable rotational stops for locating the pallet changer at these additional 45.degree. indexing positions. Also, the tool storage station is located forwardly of the work piece machining station, thus allowing the pallet changer to be positioned closer to the front of the machine tool in the region of the work piece machining station without interfering with the indexing movement of the pallet changer between stations. A docking assembly used to support pallets for transfer onto and off the pallet changer includes a pair of parallel spaced-apart side wall structures having locating cones thereon for locating transport fixtures for the pallets thereon. Lift cylinders on the side wall structures lift the transport fixtures up to bring the pallets into coaxial alignment with an adjacent end of the pallet changer. A flow dividing and control circuit is used to control the flow of hydraulic fluid to the lift cylinders so that the pallets are maintained level during raising and lowering of the pallets regardless of the load distribution on the pallets. A lift table assembly including counterbalance springs to reduce the drive motor peak current draw when lifting a load is used to lift transport fixtures with pallets thereon onto and off the docking assembly.

Dependencies are inferred from the claim text.