Abstract: An apparatus for selectively adding weight to the hollow shaft of a hand-held implement. One embodiment includes an upper cylindrical member, a lower member, and an expansion ring that fits between the upper and lower members. These components are sized slightly smaller than the inside diameter of a hollow shaft, such as a golf club shaft. Each component includes an axial bore, through which a screw with an elongated barrel extends. The axial bore of the upper member is enlarged at its upper terminus to receive the cap of the screw, and the axial bore of the lower member is threaded to receive the screw. This assembly is inserted into a hollow shaft, and as the screw is tightened, the lower member is drawn into the upper member, compressing the expander ring axially causing it to expand radially until a friction fit with the inside surface of the hollow shaft is achieved.

Abstract: A device for coupling two shaft members of differing diameters. The device includes a barrel and a reaction mass. The barrel is hollow and includes an outside coupler formed by the exterior surface of an upper portion of the barrel, an inside coupler formed by the inside surface of the barrel, and a reaction mass interface formed by the exterior surface of a lower portion of the barrel. The outside coupler is sized to fit inside a hollow end of the first shaft member. The inside coupler is sized to receive the second shaft member. The reaction mass slides over the second shaft member and into position on the reaction mass interface of the barrel. The parts are secured together with an adhesive.