Expansible mandrel

Claim 1

AN EXPANSIBLE MANDREL COMPRISING A HOLLOW CYLINDRICAL PERFORATE SHELL, AND JOURNAL PORTIONS AT THE ENDS OF SAID SHELL FOR MOUNTING THE MANDREL, SAID JOURNAL PORTIONS DEFINING THE ENDS AND SAID SHELL DEFINING THE SIDES OF AN ELONGATED CHAMBER WITHIN SAID MANDREL, AN ELONGATED FLEXIBLE HOSE MEMBER INSIDE SAID CHAMBER EXTENDING LONGITUDINALLY OF AND WITHIN SAID SHELL FOR PRODUCING EXPANSION OF THE MANDREL, ELONGATED AND RIGID TUBULAR STRUCTURE INSIDE SAID CHAMBER EXTENDING LONGITUDINALLY OF AND WITHIN SAID HOSE MEMBER FOR LIMITING THE EXTENT OF COLLAPSE OF SAID HOSE MEMBER, SAID TUBULAR STRUCTURE COMPRISING AN ELONGATED TUBE AND CONCENTRIC PLUGS AT EACH END OF SAID TUBE, SAID PLUGS HAVING ANNULAR SEATING MEANS, THE ENDS OF SAID TUBE BEING SEATED ON SAID SEATING MEANS, MEANS SECURING THE ENDS OF SAID HOSE MEMBER TO THE ENDS OF SAID TUBULAR STRUCTURE, MEANS MOUNTING THE ENDS OF SAID TUBULAR STRUCTURE IN FIXED POSITION IN SAID JOURNAL PORTIONS, MEANS IN SAID TUBULAR STRUCTURE ACCOMMODATING THE FLOW OF FLUID FROM THE INTERIOR OF SAID STRUCTURE TO THE INTERIOR OF SAID HOSE MEMBER, AND MEANS FOR INTRODUCING FLUID UNDER PRESSURE TO THE INTERIOR OF SAID TUBULAR STRUCTURE.