Abstract: A method and computer program providing for substantially automated CAD/CAM design and manufacture of custom workholding fixtures used to locate and secure workpieces on which work, such as, for example, machining, welding, or assembly, is to be performed, wherein computer models of support structures and locating and clamping devices, including dimensions and mounting geometries associated therewith, facilitate development and testing of a workholding concept, production of fixture drawings, and generation and formatting of a corresponding control program for controlling a CNC or CAM machine for manufacturing the fixture.

Abstract: A retract clamp (20) utilizes three clamp arm retraction enhancement mechanisms (26, 28, 63) to increase clamp arm (24) retraction consistency. The first retraction enhancement mechanism (26) is a bifurcated piston having a first piston member (68) and a second piston member (70). If the first piston member (68) becomes tilted and caught, the second piston member (70) continues to move allowing the first piston member (68) to right itself. The second retraction enhancement mechanism (28) comprises a clamp arm guide mechanism having a base (82), a pusher (84), and a plurality of resilient members (110-124) interposed between the base (82) and the pusher (84) to bias the pusher (84) against the clamp arm (24) and align the clamp arm (24) with a clamp arm receiving area (40) defined in a clamp arm holder (22). The third clamp arm retraction enhancement mechanism comprises a lift surface (63) on the clamp arm (24).

Abstract: A pressure reducing valve assembly (10) includes an elongated tubular body (12), a pressure reducing valve (16) for reducing the fluid pressure discharged from the valve assembly, a pressure relief valve (18) for permitting fluid to discharge from the valve assembly when the device to which the valve assembly is coupled experiences an over-pressure condition, and a reset valve (20) for resetting the pressure reducing valve when the fluid pressure on the high pressure side of the valve assembly is reduced below a pre-selected reset level. The pressure reducing valve, pressure relief valve, and reset valve are all positioned within the tubular body and coaxially aligned along the longitudinal axis (14) of the body. The reset valve is positioned within the confines of the pressure reducing valve, and the pressure relief valve utilizes the same compression spring (90) as the pressure reducing valve.

Abstract: A hydraulically-operated swing clamp (10) for holding and clamping a workpiece (14) to a fixture (12) is disclosed. The swing clamp (10) includes an improved cam assembly (24) that swings its clamping head (22) away from the workpiece (14) when the piston (22) of the clamp (10) is shifted to its extended, unclamped position. The cam assembly (24) includes at least one cam track or groove (38,40,42) and a corresponding cam follower ball (44) received within the groove (38,40,42). The cam track (38,40,42) includes a central arcuate region (48) and a pair of substantially planar side faces (50,52) extending tangentially from the central arcuate region (48). The central arcuate region (48) has a radius of curvature substantially equal to the radius of curvature of the cam follower ball (44). The planar side faces (50,52) extend tangentially away from the central arcuate region (48) and the cam follower ball (44).

Abstract: A swing clamp apparatus adapted to be mounted adjacent a work surface includes a housing provided with a bore defining a longitudinal axis, and a piston received within the bore and being movable in the direction of the longitudinal axis. A clamping arm is supported on the piston for movement therewith between a clamping position and a releasing position. A first passageway is provided for delivering hydraulic fluid from a source of pressurized fluid to the first bore section of the housing to move the piston in a first direction and additional structure shifts the piston in a second direction opposite the first direction. The passageway includes a plurality of external ports formed in the housing and a manifold with which the plurality of ports communicate to permit fluid to be delivered to the first passageway, and a number of plugs are used for plugging any of the plurality of ports not used during delivery of fluid to the passageway in order to prevent leakage of fluid from the manifold.

Abstract: A hydraulic work support apparatus includes a plunger that is axially movable between a loaded position and an unloaded position and that is adapted to support a compressive load at one axial end thereof. The apparatus also is provided with structure for retaining the plunger in the loaded position, the plunger retaining structure including a tubular sleeve provided with a plunger-engaging segment having a first end adjacent the one axial end of the plunger and a second end remote from the first end. The plunger-engaging segment may be forced radially inward into pressing contact with the plunger to exert a friction force on the plunger which prevents the plunger from moving while in the loaded position. The friction force experienced by the sleeve when pressing contact exists between the sleeve and the plunger has a minimum magnitude at the first end of the plunger-engaging segment and a progressively larger magnitude toward the second end of the segment.

Abstract: A hydraulic work support assembly includes a externally threaded housing and a sleeve pressed into the bore of the housing which in turn receives a cylindrical plunger. The plunger may be extended to any one of a number of positions and thereafter locked in place upon application of hydraulic pressure to an annular chamber between the sleeve and the housing which causes the sleeve to contract and grip the complimental plunger. The end of the sleeve and the end of the housing lie in a common plane transverse to the central axis of the housing, and seals are carried by the housing and the sleeve adjacent the ends thereof in contact with opposite sides of an annular chamber formed in the bottom of a recess of base structure.