Apparatus for assembling fins on a tube

Claim 1

IN AN APPARATUS FOR FIXING A STACK OF FINS ON A TUBE OF EXPANDABLE MATERIAL, SAID FINS HAVING A PORTION DEFINING AN OPENING SLIGHTLY LARGEER THAN THE TUBE, MEANS BETWEEN SAID FINS FOR SPACING SAID FINS IN SAID STACK, THE COMBINATION COMPRISING, A FRAME, AN ELONGATED HORIZONTAL TROUGH CARRIED BY THE FRAME FOR SUPPORTING A STACK OF FINS WITH THE OPENINGS IN THE FINS OF SAID STACK IN SUBSTANTIAL ALIGNMENT, SEALING FIXTURES MOUNTED AT SPACED POINTS ALONG SAID TROUGH FOR MOUNTING A TUBE EXTENDING THROUGH THE ALIGNED FIN OPENINGS AND PROJECTING FROM BOTH ENDS OF THE FIN STACK, EACH SAID SEALING FIXTURE HAVING A TUBULAR MEMBER SEALINGLY RECEIVING THE RESPECTIVE TUBE END, ONE TUBULAR MEMBER BEING SLIDABLY MOUNTED ON THE RESPECTIVE FIXTURE AND HAVING AN INITIAL POSITION ENCASING THE ADJACENT END OF THE TUBE AND ABUTTING THE FIN STACK, AND FIN STACK BEING LOCATED BETWEEN SAID SEALING FIXTURES, A CONNECTION THROUGH ONE OF SAID SEALING FIXTURES TO THE INSIDE OF THE TUBE FOR CONVEYING PRESSURE FLUID TO EXPAND THE TUBE INTO ENGAGEMENT WITH THE PORTIONS OF THE FINS SURROUNDING THE TUBE, SAID SLIDABLY MOUNTED TUBULAR MEMBER HAVING AN AREA EXPOSED TO SAID PRESSURE FLUID TENDING TO MOVE THE LATTER MEMBER IN THE DIRECTION TOWARD THE STACK SO AS TO MAINTAIN ABUTMENT AGAINST THE FIN STACK AND SAID STACK CONFINED BETWEEN SAID FIXTURES WITH THE FINS THEREOF SEPARATED BY SAID SPACING MEANS DESPITE TUBE SHORTENING WHILE EXPANSION PROGRESSES.