Machining center with an integral continuous pressure hydraulic clamping system

In a machining center for machining parts carried by a fixture, the machining center comprising:

• a housing defining a fixture loading area for receiving the fixture and a machining area for receiving the fixture during the machining of the parts;
• a machining tool located in the machining area for performing machining operations on a part carried by the fixture;
• a pallet changing station comprising a vertically-orientated rotating column assembly and a platform for supporting the fixture, with the platform mounted to the column and having a first portion located in the loading area and a second portion located in the machining area, wherein the rotation of the column assembly moves the platform first portion from the loading area to the machining area and the platform second portion from the machining area to the loading area, so that the fixture is moved from the loading area to the machining area for performing the machining operations on the part and from the machining area to the loading area for removing the machined parts from the fixture;
• a clamping system comprising a hydraulic conduit extending into the pallet changing station for supplying pressurized hydraulic fluid to the fixture from a source of pressurized hydraulic fluid for clamping the parts to the fixture;
• the improvement comprising:
• the column assembly comprises a portion having an internal bore forming part of the hydraulic conduit for fluid connection of the hydraulic fluid source with the clamping system.