Vacuum-sealed gas-bearing assembly

Claim 1

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.