Abstract: A workholder with a sleeve carried by a body and providing at least in part a circumferentially continuous fluid chamber between them and at least two circumferentially spaced apart locators carried by the body axially over the sleeve and projecting radially of the sleeve. A pressurized fluid in the chamber can change the diameter of the sleeve to move the locators generally radially relative to the body into firm engagement with a workpiece so that it is carried by the workholder. The locators may be received in part in a collar received at least in part axially over the sleeve with a portion of each locator projecting radially of the collar.

Abstract: A workholder to hold a workpiece, including a main body partially defining a fluid chamber, and a bladder carried by the main body with an interference fit, further defining the fluid chamber, and composed of an 80 to 100 durometer Shore A scale hardness polymer of a 12:1 to 18:1 diameter-to-wall-thickness ratio. Annular seals may further define the fluid chamber, and are disposed radially between the bladder and main body and axially adjacent the fluid chamber, and are composed of a 60 to 80 durometer Shore A scale hardness polymer. A collet is carried and driven by the bladder for gripping engagement with the workpiece.

Abstract: A stepped collet includes a first section of generally hollow cylindrical shape having a first outer diameter and an inner diameter, a wall extending radially inwardly from an outboard end of the first section, and a second section of generally split cylindrical shape cantilevered from the wall and having a second outer diameter smaller than the first outer diameter.

Abstract: A workholding apparatus includes a body, and a workholding sleeve composed of metal and carried by the body. A fluid chamber receives a fluid between the body and the workholding sleeve. Under fluid pressure, the sleeve is radially displaceable and recoverable to a high degree. For example, when displaced under fluid pressure, the sleeve experiences substantially complete and repeatable strain recovery of at least about 2% of its overall cross-sectional area. Preferably, the sleeve is composed of Nitinol.

Abstract: A workholding apparatus includes a body, and a workholding sleeve composed of metal and carried by the body. A fluid chamber receives a fluid between the body and the workholding sleeve. Under fluid pressure, the sleeve is radially displaceable and recoverable to a high degree. For example, the sleeve is radially displaceable to at least one percent in diameter with runout within about 0.03% of its diameter, and after release of fluid pressure repeatably recovers to within about 0.01% of its original relaxed diameter. In another example, when displaced under fluid pressure, the sleeve experiences substantially complete and repeatable strain recovery of at least about 2% of its overall cross-sectional area. Preferably, the sleeve is composed of Nitinol.

Abstract: A workholding apparatus includes a body, and a workholding sleeve composed of metal and carried by the body. A fluid chamber receives a fluid between the body and the workholding sleeve. Under fluid pressure, the sleeve is radially displaceable and recoverable to a high degree. For example, when displaced under fluid pressure, the sleeve experiences substantially complete and repeatable strain recovery of at least about 2% of its overall cross-sectional area. Preferably, the sleeve is composed of Nitinol.

Abstract: A workholder to hold a workpiece, including a main body partially defining a fluid chamber, and a bladder carried by the main body with an interference fit, further defining the fluid chamber, and composed of an 80 to 100 durometer Shore A scale hardness polymer of a 12:1 to 18:1 diameter-to-wall-thickness ratio. Annular seals may further define the fluid chamber, and are disposed radially between the bladder and main body and axially adjacent the fluid chamber, and are composed of a 60 to 80 durometer Shore A scale hardness polymer. A collet is carried and driven by the bladder for gripping engagement with the workpiece.

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 workholding apparatus including a body and a drive member carried by the body, so that the drive member and body partially define a fluid chamber therebetween for containing a fluid. The drive member includes an annular flange that axially abuts and that attaches to the body to resist torsional twisting of the drive member relative to the body. A driven member is also carried by the body and includes multiple displacement reliefs therein. Interengagement features are provided between the driven member and other components of the workholding apparatus, such as the drive member, to resist torsional twisting of the driven member.

Abstract: A workpiece holding apparatus comprises a body, a bladder carried by the body, and a sleeve that is carried by the bladder. A fluid chamber is at least partially defined by the body and the bladder for containing a fluid therein. The bladder comprises at least one first polymer-containing section composed of a first polymer-containing material and is adapted to radially deflect the sleeve into engagement with the workpiece. The bladder further comprises at least one second polymer-containing section disposed adjacent to the first polymer-containing section(s) and is composed of a second polymer-containing material that is less flexible than the first polymer-containing material and where at least a portion of the second polymer-containing section(s) are constructed to engage elastomeric seals of the body of the workpiece holding apparatus to thereby seal pressurized fluid within the fluid chamber.

Abstract: A workholding apparatus including a body and a drive member carried by the body, so that the drive member and body partially define a fluid chamber therebetween for containing a fluid. A driven member is also carried by the body and includes multiple displacement reliefs therein. An intermediate member with a displacement relief is received between the drive and driven members. The intermediate member prevents the drive member from extruding through the displacement reliefs in the driven member under fluid pressures of the fluid, thereby enabling use of the apparatus under higher performance applications that would not be possible without the intermediate member.

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 hydrostatic tool holder having a displaceable metal sleeve formed with a plurality of circumferentially spaced and longitudinally extending slots and a flexible, polymeric ring defining at least in part a fluid chamber to separate the fluid in the chamber from the sleeve to prevent the fluid from escaping through the slots in the sleeve. The slots in the metal sleeve enable a large displacement of the sleeve through the polymeric ring so that the hydrostatic tool holder may be used with workpieces having rough finishes, such as cast metal workplieces like cylinder liners for internal combustion engines, which as cast have relatively rough surfaces and relatively low dimensional accuracy.

Abstract: A hydrostatic holding device has a first actuator constructed to increase the pressure of a hydraulic fluid within a pressure chamber to urge a metal sleeve into firm engagement with a workpiece received in a hydrostatic sleeve and a second actuator constructed to relieve the high pressure within the system to permit the workpiece to be removed from the sleeve when desired. Preferably, the first and second actuators are separate cylinders each having pistons displaceable by separate actuating rods to conveniently achieve the increased pressure needed to firmly hold the workpiece and the bleeding or relieving of the pressure so that the workpiece can be removed from a holder. A check valve downstream of the first actuator prevents reverse flow of the hydraulic fluid from downstream of the check valve back into the first actuator and thereby permits the increased pressure to be maintained independently of the first actuator.

Abstract: A collet for holding and precisely locating a cutting tool within a tool holder has a bore constructed to receive a shank of the cutting tool therein, a hydrostatically displacable sleeve received in the bore, a piston received within a passage communicating with the sleeve and displaceable to pressurize fluid within the passage to actuate the sleeve and a retaining nut threadably received on the tool holder to displace the piston to pressurize the fluid within the collet as the nut is rotated on the tool holder. The pressurized fluid within the collet acts substantially uniformly across the sleeve to urge the sleeve into firm engagement with the cutting tool to firmly hold and accurately and repeatably locate the cutting tool within the collet. Also, the pressurized fluid acts substantially uniformly on the interior wall of the collet to substantially uniformly urge the collet into firm engagement with the tool holder to firmly hold and accurately and repeatably locate the collet within the tool holder.

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.