Abstract: An air-mechanical expanding chuck for supporting a core for winding webs. A cylindrical chuck body defines a chamber which contains a piston with its piston rod extending out of the chamber for insertion into the core. The piston rod forms a tapered arbor at its end. Three gripping elements bear against flat surfaces formed on the tapered arbor. By applying air to one side of the piston, the arbor is moved inboard relative to the core and the gripping elements are thereby expanded to engage the core's interior. The chuck body's inward face is provided with radially extending T-grooves to receive corresponding T-formed outer ends of the gripping elements which are movable radially in the T-grooves. The gripping elements are readily removable from the grooves and replaceable by elements of other sizes for different diameter cores.

Abstract: A self-contained cylindrical expandable mandrel comprising a closed liquid hydraulic system pressurized by the smaller end of a piston, the larger end of which piston is compressed by a gas, such as compressed air from an outside source through a hose connectable to a pneumatic tire-type check valve on the unit. The closed liquid hydraulic system from the smaller end of the piston flexes a plurality of diaphragms directly urging plungers radially outwardly around the cylindrical mandrel for pressing buttons, bars, or leaves against the inside hollow cores of rolls of web or sheet material for positively grabbing these rolls for rotation directly with the shaft connected to the mandrel.

Abstract: A shaft for gripping the inside diameter of the cores for winding webs such as of paper, plastic films, metal foils, fabric, and the like, which shaft has integrally therein a longitudinal fluid pressure manifold duct connecting spaced radially projectable core gripping rams or pistons. The fluid may be a gas such as air for smaller shafts, but preferably the fluid is a dimensional stable hydraulic liquid which may contain colloidally suspended metallic solids. Preferably the gripping rams or pistons are controlled from an hydraulic master cylinder mounted near one end of the shaft to form an integral unit. Preferably also the master cylinder and rams are statically sealed by rolling type diaphragm means. The piston in the master cylinder may be operated by a circumferential sleeve threaded to said cylinder and locked in position by a lock ring or nut.