Tool for cold forging tubular members

A tool for forging tubular members comprising

• a cylindrical body,
• a resilient sleeve surrounding said body,
• means securing the ends of said sleeve to said body,
• means for delivering fluid under pressure to expand said sleeve,
• dual upper anti-extrusion means surrounding the upper end of said sleeve and coating to move outward with the expansion of the sleeve to close any gap through which said sleeve could extrude when exposed to internal pressure, and
• dual lower anti-extrusion means surrounding the lower end of said sleeve and coating to move outward with the expansion of the sleeve to close any gap through which said sleeve could extrude when exposed to internal pressure,
• said anti-extrusion means include
• expandable rings,
• the outer of each of said dual rings movable a limited distance outward, and
• the inner of each of said dural rings movable a greater distance outward than said outer rings,
• each of said rings include
• a plurality of ring segments, and means biasing said segments inwardly,
• said segments are cut from a metal ring having the largest diameter which said segments are expected to assume when installed on said sleeve,
• said segments when cut from their ring are cut at angles to the radius of the ring to allow said rings to have an irising action when moved to a smaller than their maximum desired diameter.

A tool for forging tubular members comprising

• a cylindrical body,
• a resilient sleeve surrounding said body,
• means securing the ends of said sleeve to said body,
• means for delivering fluid under pressure to expand said sleeve,
• dual upper anti-extrusion means surrounding the upper end of said sleeve and coating to move outward with the expansion of the sleeve to close any gap through which said sleeve could extrude when exposed to internal pressure, and
• dual lower anti-extrusion means surrounding the lower end of said sleeve and coating to move outward with the expansion of the sleeve to close any gap through which said sleeve could extrude when exposed to internal pressure,
• said anti-extrusion means include
• expandable rings,
• the outer of each of said dual rings movable a limited distance outward, and
• the inner of each of said dural rings movable a greater distance outward than said outer rings,
• each of said rings include
• a plurality of ring segments, and means biasing said segments inwardly,
• said segments are cut from a metal ring having the largest diameter which said segments are expected to assume when installed on said sleeve,
• said segments are cut from their ring along lines which are at an angle substantially less than ninety degrees to a tangent at the point of entry of the cut into the exterior surface of the metal ring.