Abstract: An expansible shaft with an actuator having a bore through which the operating rod extends, and, adjacent one end of the actuator, a surface inclined relative to the rod which at least partially defines a recess extending radially outward of the bore. A retaining member is mounted in a recess in the outer surface of the rod in position for engaging the surface of the actuator recess so that, when the actuator is forced relative to the rod towards the retaining member, interaction between the retaining member and the surface of the actuator recess causes application of a radially inwardly directed force on the retaining member. A bearing surface at one axial end of the operating rod is defined by a portion of the exterior of a sphere and a drive screw engages and is arranged to apply force to the bearing surface.

Abstract: An expansible shaft in which an axially-movable cam forces a core engager radially outward into engagement with a surrounding core. A cam follower attached to the core engager slidingly engages a cam surface of the cam, a recessed slot is parallel to the cam surface, and one end of a cross-bore in the cam follower overlies and follows the slot as the cam follower slides along the cam surface. A second bore perpendicularly intersects the cross-bore. A first member is mounted in and forms a slip-fit with the cross-bore, a second member is mounted in the second bore, and the length of the first member is such that a portion of it projects into the slot when the second member is within the bore intersection, but the entire first member fits within the cross-bore when the second member is withdrawn from the bore intersection.