Abstract: An apparatus for controlling relative movement between two interconnected bodies includes a first end cap, a second end cap having an opening, a sleeve interconnecting the end caps to define a chamber between the sleeve and the end caps, a piston assembly including a piston rod extending through the opening of the second end cap, a piston connected to the piston rod, received in the chamber to define at least two fluid chambers on opposed sides of the piston, and a plurality of rollers carried by the piston for rolling engagement with the sleeve. A fluid flow path provides communication between the fluid chambers and provides a restricted fluid flow rate therethrough to control the rate of fluid transfer between the fluid chambers and permit fluid pressure to increase in a chamber into which the piston is being moved to provide a force on the piston opposing its movement.

Abstract: Workpiece chucking apparatus includes a chuck body mounting a first plurality of prepositioning lock-up fingers and a second plurality of gripping fingers. The lock-up fingers are biased together radially outwardly or inwardly into engagement with a peripheral wall of a workpiece to initially locate and support the wall of the workpiece in a centered position with respect to a central axis of the chucking apparatus. An inflatable bladder flexes the remaining gripping fingers into gripping engagement with the peripheral wall to further radially support the wall in preparation for machining, without disturbing the prepositioning of the workpiece.

Abstract: A chuck for gripping workpieces to be machined has a chuck body with a workpiece support surface for supporting a workpiece to be machined. Generally radially movable centering and gripping collet fingers are concentrically supported by the chuck body. An inflatable bladder is further mounted on the chuck body in generally concentric relationship with the fingers. Control mechanism is provided for initially radially moving the centering fingers to cause them to move radially and center said workpiece, and then supplies a fluid under pressure to inflate the bladder and move the gripping fingers generally radially to fully grip the centered workpiece.

Abstract: Workpiece chucking apparatus includes a chuck body mounting a first plurality of lock-up fingers and a second plurality of gripping fingers. The lock-up fingers are individually biased radially outward into engagement with a peripheral wall of a workpiece to initially support the workpiece in a predetermined position irrespective of the eccentricity of the peripheral wall with respect to other portions of the workpiece which are first located concentrically with the chuck axis. An inflatable bladder flexes the remaining gripping fingers into gripping engagement with the peripheral wall to further radially support the wall in preparation for machining, without disturbing the prepositioning of the workpiece.