Abstract: A machine tool comprising a base, with a guide surface, a workpiece holder on the base, a movable tool carriage, and a motor for advancing the carriage along the guide surfaces toward the workpiece. Hydrostatic bearings are situated in the carriage for discharging fluid, such as oil, into the narrow gap defined between the carriage and the guide surface. A pre-load rail is secured to the movable carriage, and a plurality of pockets are defined in the pre-load rail. A hydrostatic pre-load piston, with an enlarged head and a depending base, is located in each pocket. A shallow depression is formed in the face of each piston, and an annular wall surrounds the depression, so that the piston restores itself to an equilibrium condition. The pre-load pistons are located in opposition to the hydrostatic bearings. An O-ring encircles the base of the piston, and allows floating, and tilting, movement of the piston within the pocket, while serving as a seal for the pocket.

Abstract: A machine tool comprising a base, with a guide surface, a workpiece holder on the base, a movable tool carriage, and a motor for advancing the carriage along the guide surface toward the workpiece. Hydrostatic bearings are situated in the carriage for discharging fluid, such as oil, into the narrow gap defined between the carriage and the guide surface. A pre-load rail is secured to the movable carriage, and a plurality of pockets are defined in the pre-load rail. A hydrostatic pre-load piston, with an enlarged head and a depending base, is located in each pocket. A shallow depression is formed in the face of each piston, and an annular wall surrounds the depression, so that the piston restores itself to an equilibrium condition. The pre-load pistons are located in opposition to the hydrostatic bearings. An O-ring encircles the base of the piston, and allows floating, and tilting, movement of the piston within the pocket, while serving as a seal for the pocket.

Abstract: A tapered bearing for the drive drum assembly of a belt grinding machine that employs multiple, parallel, abrasive grinding belts, and back-up shoes for pressing the belts against the surfaces on a workpiece to be ground. The drive drum assembly, in cooperation with small pulleys operatively associated with the contouring head, keeps the abrasive belts properly trained. The central shaft of the drive drum assembly, which has a plurality of large pulleys and spacers positioned therealong, is secured between a fixed bearing support and a laterally movable support bracket. A tapered bearing is fastened to one end of the central shaft, and a complementary shaped aperture is defined in a spindle retained in the movable support bracket. When the movable support bracket is shifted inwardly, by the hydraulic circuitry of the grinding machine, the tapered bearing fits snugly into the aperture so that the drive drum assembly is supported in a rigid, sag-free manner.

Abstract: A method of forming a hydrostatic nut that cooperates with a lead screw for translating a wheel head, or carriage, on a grinding machine, such as a cam grinder. A lead screw, which is externally threaded, is inserted into a cylindrical mold, which is internally threaded. The lead screw is retained therein by pressure plates that seal off opposite ends of the open bore of the mold.A continuous cavity is defined between the internal threads on the nut and the external threads on the lead screw. An epoxy resin or other castable polymer is introduced through an inlet port in the mold into the cavity. The castable polymer is allowed to cure into a rigid mass that adheres to the internal threads on the mold. The lead screw is removed, and the mold may be machined to its final configuration as a hydrostatic nut.At least one helical channel is defined in the outer surface of the rigid mass adhered to the mold.

Abstract: A grinding machine provided with a spindle rotating under the influence of a cantilever mounted rare earth permanent magnet motor. Hydrostatic fluid film bearings are provided between the ends of the spindle and a bronze bearing to support the spindle in such a manner so as to eliminate wear. A single oil reservoir is used to supply oil to the hydrostatic bearings, as well as to the cooling jacket of the motor.

Abstract: A method of forming a hydrostatic nut that cooperates with a lead screw for translating a wheel head, or carriage, on a grinding machine, such as a cam grinder. A lead screw standard, or master, which is externally threaded, is inserted into a cylindrical mold, which is internally threaded. The standard is retained therein by pressure plates that seal off opposite ends of the open bore of the mold. Beads of wax, or tape, or some other rigid instrumentality, are adhered to the exterior surfaces of the helical threads on the standard, while the rest of the standard is treated with a release coating.A continuous cavity is defined between the internal threads on the nut and the external threads on the standard. An epoxy resin or other castable polymer is introduced through an inlet port in the mold into the cavity. The castable polymer is allowed to cure into a rigid mass that adheres to the internal threads on the mold except for the helical beads.