Coldwork holes with seamless sleeve and uniform expansion

An apparatus for coldworking material around a hole in a workpiece, wherein the hole has a hole diameter, comprising:

• a sleeve comprising a tubular section and a first interlocking portion, wherein the tubular section extends from a proximal tube end to a distal tube end and comprises an outer cylindrical sidewall and an inner frustoconical sidewall, wherein the proximal tube end has a greater thickness than the distal tube end, wherein the inner frustoconical sidewall has a minimum inner sidewall diameter at the proximal sleeve end and a maximum inner sidewall diameter at the distal sleeve end, and wherein the outer cylindrical sidewall is positioned within the hole;
• a mandrel assembly comprising a mandrel and a mandrel adaptor, wherein the mandrel is comprised of a working section extending from a fixed rear end of the mandrel, wherein a frustoconical exterior surface of the working section extends between a distal working end and a proximal working end at a taper angle complementary to the inner frustoconical sidewall of the sleeve, wherein the proximal working end has a minimum mandrel diameter less than the minimum inner sidewall diameter of the sleeve, wherein the distal working end has a maximum mandrel diameter less than the hole diameter and greater than the maximum inner sidewall diameter of the sleeve, and wherein the sleeve surrounds a portion of the working section of the mandrel;
• a spindle assembly comprising an axially fixed section and a translating section, wherein the axially fixed section rotates around a central longitudinal axis, wherein the translating section is operatively connected to and rotates with the axially fixed section, wherein the translating section slides axially relative to the axially fixed section, and wherein the mandrel assembly is fixedly connected to and slides axially with and rotates with the translating section;
• a sleeve seat assembly comprising a sleeve seat and a second interlocking portion, wherein the mandrel adaptor slidingly engages with and rotates the sleeve seat with the spindle assembly, wherein the sleeve seat engages with and rotates the second interlocking portion while rotating with the mandrel adaptor, and wherein the second interlocking portion engages the first interlocking portion of the sleeve and rotates the sleeve with the mandrel adaptor;
• a motor in operative engagement with the axially fixed section of the spindle assembly and rotates the spindle assembly, wherein the spindle assembly rotates the mandrel assembly, and wherein the mandrel assembly rotates the sleeve seat assembly and the sleeve;
• and
• an actuator in operative engagement with the translating section of the spindle assembly, wherein the actuator axially extends and axially retracts the translating section relative to fixed section, and wherein the mandrel assembly axially extends and axially retracts with the translating section.

A method for coldworking material around a hole in a workpiece, wherein the hole has a hole diameter, the method comprising the steps of:

• providing a seamless sleeve comprising a tubular section and a first interlocking portion, wherein the tubular section extends from a proximal tube end to a distal tube end and comprises an outer cylindrical sidewall and an inner frustoconical sidewall, wherein the proximal tube end has a greater thickness than the distal tube end, and wherein the inner frustoconical sidewall has a minimum inner sidewall diameter at the proximal sleeve end and a maximum inner sidewall diameter at the distal sleeve end;
• providing a mandrel, wherein the mandrel is comprised of a working section extending from a fixed rear end of the mandrel, wherein a frustoconical exterior surface of the working section extends between a distal working end and a proximal working end at a taper angle complementary to the inner frustoconical sidewall of the sleeve, wherein the proximal working end has a minimum mandrel diameter less than the minimum inner sidewall diameter of the sleeve, and wherein the distal working end has a maximum mandrel diameter less than the hole diameter and greater than the maximum inner sidewall diameter of the sleeve;
• placing the seamless sleeve around the working section of the mandrel;
• inserting the distal working end of the mandrel through the hole in an extended position;
• after the inserting step, positioning the outer cylindrical sidewall of the seamless sleeve within the hole;
• retracting the mandrel from the extended position to partially retracted position and a fully retracted position while keeping the outer cylindrical sidewall of the seamless sleeve within the hole, wherein the exterior surface of the mandrel's working section initially engages the inner frustoconical sidewall of the seamless sleeve in the partially retracted position and the distal working end is closer to the hole in the partially retracted position relative to the extended position, and wherein the distal working end is closest to the hole in the fully retracted position and the exterior surface of the mandrel's working section radially expands the inner frustoconical sidewall and the outer cylindrical sidewall of the seamless sleeve between the partially retracted position and the fully retracted position;
• extending the mandrel from the retracted position to at least one of the extended position and an intermediate extended position between the partially retracted position and the extended position;
• rotating the sleeve and the mandrel after the extending step, wherein a connection between the mandrel and the sleeve causes the sleeve to rotate with the mandrel, and wherein the connection allows the mandrel to translate relative to the sleeve;
• and
• removing the seamless sleeve and the mandrel from the hole.