Expandible devices for internally gripping cores or the like
OwnerDavid Blackburninventor
Life of this patent
Estimating the term…
Abstract
An expandible device for internally gripping a core carrying a web of material has jaw segments forming an outer cylinder surrounding a body member which may be solid or hollow. Balls are arranged in recesses around the exterior of the body member and the jaw segments have inner grooves which receive the balls. The grooves are specially shaped to taper in depth and co-operate with the disposition of the balls so that part rotation of a core supported on the jaw segments will cause the grooves of these jaw segments to progressively run over the balls, thereby to cause the jaw segments to rise and expand outwardly from the body member into frictional gripping contact with the interior of the core.
Claims16
A-self-expandible device for internally gripping hollow cores or the like to impart torque thereto;
- said device comprising a body member, a cylindrical structure surrounding the body member for effecting frictional drive contact with a hollow core, the body member and the cylindrical structure being relatively rotatable about an axis of the device, the body member and the cylindrical structure having curvilinear confronting surfaces, the cylindrical structure being composed of a plurality of jaw segments, means for retaining the jaw segments on the body member, balls between the confronting surfaces and slender elongate, arcuate circumferential grooves formed in one of the confronting surfaces in registry with the balls, wherein each groove has a tapered depth which varies around the axis of rotation and is described with a radius of curvature similar in magnitude to that of the other confronting surface and the balls are positionally secured in relation to the other confronting surface to locate in said grooves;
- wherein rotation or relative partial rotation between the cylindrical structure and the body member causes shallower regions of the grooves to engage with the balls to move the jaw segments progressively outwardly from the body member to effect said frictional drive contact with the hollow core.
Dependencies are inferred from the claim text.