Vacuum-sealed gas-bearing assembly

An integral vacuum sealed gas-bearing housing assembly comprising, in combination:

• a first sub-assembly housing means establishing a first internal chamber, said first sub-assembly having a first planar surface about the periphery of said first chamber and a plurality of vacuum plenums delineated by adjacent lands and extending to said planar surface;
• a plurality of individual plenum ducts connected to said plenums;
• manifold means for interconnecting said plenum ducts to vacuum pump means;
• at least one gas-bearing means within said first sub-assembly about said first planar surface and extending about the perimeter of the chamber and spaced laterally from said plenums;
• at least one gas duct within the side wall of said first housing and interconnected to the gas-bearing means;
• manifold means for interconnecting the gas duct to a gas pump means to pump gas therein at a pressure above atmospheric pressure;
• a second sub-assembly housing means forming a second internal chamber communicating with said first internal chamber, said second sub-assembly housing means having a second planar surface, said second planar surface being in face-to-face orientation with said first planar surface and overlapping said individual plenums and said gas-bearing groove;
• and
• driver means for moving said second sub-assembly housing means relative to said first sub-assembly housing means whereby gas pumped within said gas duct establishes a gas bearing about the interface of said first and second planar surfaces to establish a spacing intermediate the first and second sub-assemblies and said vacuum pump means removes gas from said interface intermediate the gas-bearing means and said internal chambers.