Abstract: A mechanically actuated workpiece holding apparatus comprising a collet at least partially composed of a plastic material. The collet may include cantilevered leaves and may be a plastic coating over a metal substrate.

Abstract: A mechanically actuated workpiece holding apparatus comprising a collet at least partially composed of a plastic material. The collet may include cantilevered leaves and may be a plastic coating over a metal substrate.

Abstract: A tool holder with an elongate and expanding sleeve within a confining recess of a machine spindle to circumferentially engage the machine spindle and accurately, firmly and concentrically engage a machine tool adjacent to a machine spindle. In one form, a tapered expanding sleeve is disposed about the exterior of the tool holder and is received between the tool holder and the machine spindle in a tapered recess of the machine spindle. A hydraulic fluid is disposed between the tool holder and the expanding sleeve and is pressurized to expand the sleeve into firm engagement with the machine spindle. In another form, the expanding sleeve is received interiorly of a central bore within the tool holder and longitudinal grooves are provided in the sleeve about its circumference forming generally individual fingers.

Abstract: A center tool with a shank receivable in a sleeve carried by a body of a holder which may have cutters on a work surface disposed outward of the sleeve. A hydraulic actuator forces the sleeve radially inward to grip, releasably retain and center the shank of the center tool to permit rapid removal and replacement of the center tool. The actuation may also react radially outwardly to move the body and cutters radially outward to vary and adjust the diameter of the bore machined by the cutters on work surfaces. Preferably, the tool holder has a shank received in a chuck with the holder or chuck having a hydraulically actuated sleeve to retain the tool holder in the chuck.

Abstract: A tool holder for a machine tool is provided with a tool shank clamping mechanism in the form of an expanding or contracting sleeve, hydraulically actuated, and the chuck has an annular groove aft of an annular collar on the clamping mechanism. Circumferentially spaced conical screws, mounted axially in the collar, bear against the body of the tool chuck and allow fractional tilting of the clamping mechanism relative to the true holder and spindle axis to provide exact centering of the cutting end of the mounted tool.

Abstract: A zero-deflection support chuck is provided for gripping a load shaft which includes a stable support body having a bore, a gripping sleeve closely embracing the load shaft and a pressure sleeve within the bore and surrounding the gripping sleeve. The outer surface of the pressure sleeve is exposed to a pressure medium from a pressure source. The outer surface of the pressure sleeve has sealing lands at each end cooperating with the ends of the bore and a spiral groove and lands extending between the sealing lands. The lands between the grooves have the same diameter as the bore in the body. Pressure in the spiral grooves and the inner surface of the body bore moves the gripping sleeve tightly against the support shaft along the entire length of the sleeves and locks the shaft in a stable position.