Abstract: A ball hitch assembly consisting of: a center pin mountable on a tow bar and having an axial extent; a hitch ball with a central opening mountable on the center pin; a cooperating locking pin and groove structure provided one on the center pin and the other on the hitch ball, with the groove having an entryway through which the locking pin can pass as the center pin is directed into the hitch ball central opening, with the locking pin being movable within the groove to allow the hitch ball to be placed in an operative position on the center pin; and locking structure defined cooperatively by the locking pin and groove for preventing the hitch ball in its operative position from being disassembled from the center pin by drawing the hitch ball in one axial direction and turning the hitch ball in either direction of rotation about the axis of the center pin.

Abstract: A device for gripping the insides of cores of rolls of materials, and comprising a polygonal central cam, multiple gripping cylinders which are held against the cam by resilient retainer rings and a cylindrical sleeve which retains the gripping cylinders in longitudinal slots passing through the sleeve. The gripping cylinders are caused to move radially inward and outward when the sleeve is rotated relative to the cam and the cylinders are urged outward by the corners of the cam or inward by the resilient retainer rings as the cylinders move from the corners of the polygon to the sides of the polygon.