Method and apparatus forming serpentine fins

Claim 1

THE METHOD OF FORMING A SERPENTINE FIN STRUCTURE FOR A HEAT EXCHANGE STRUCTURE, SAID FIN STRUCTURE COMPRISING A PLURALITY OF FIN ELEMENTS ADAPTED TO BE CONNECTED ALONG THEIR LATERAL EDGES TO RESPECTIVE TUBE ELEMENTS OF THE HEAT EXCHANGE STRUCTURE WITH EACH FIN ELEMENT BEING CONNECTED AT ONE OF ITS EDGES TO A CORRESPONDING EDGE OF AN ADJACENT FIN ELEMENT AT ONE SIDE THEREOF AND AT ITS OPPOSITE EDGE TO THE CORRESPONDING EDGE OF THE ADJACENT FIN ELEMENT AT THE OTHER SIDE THEREOF, PROVIDING A GENERALLY CORRUGATED OR SERPENTINE SHAPED STRUCTURE, THE CONNECTING PORTIONS BETWEEN ADJACENT FIN ELEMENTS PROVIDING MEANS BY WHICH THE FIN ELEMENT MAY BE CONNECTED TO ASSOCIATED TUBE ELEMENTS OF THE HEAT EXCHANGE STRUCTURE, SAID METHOD COMPRISING THE STEPS OF FORMING A STRIP OF METAL INTO A GENERALLY CORRUGATED SHAPE, SIMULTANEOUSLY REDUCING AND TAPERING THE THICKNESS OF THE STRIP BY SQUEEZING AND COINING AT INTERMEDIATE PORTIONS OF THE FING ELEMENTS, WHEREBY THE LATTER GENERALLY TAPER IN THICKNESS FROM THEIR LATERAL EDGES TOWARD THE CENTRAL PORTION THEREOF, AND STRETCHING THE FIN ELEMENT AT SAID INTERMEDIATE PORTIONS OF REDUCED THICKNESS AS MAY BE NECESSARY TO PROVIDE SAID FIN STRUCTURE WITH FIN ELEMENTS OF UNIFORM WIDTH, GATHERING THE CORRUGATIONS TO BRING THE LATTER INTO CLOSER PROXIMITY THAN DESIRED IN THE FINISHED STRUCTURE, AND RELEASING THE CORRUGATIONS TO PERMIT EXPANSION THEREOF TO THE DESIRED SPACING.

Claim 2

THE METHOD OF FORMING A SERPENTINE FIN STRUCTURE FOR A HEAT EXCHANGE STRUCTURE, SAID FIN STRUCTURE COMPRISING A PLURALITY OF FIN ELEMENTS ADAPTED TO BE CONNECTED ALONG THEIR LATERAL EDGES TO RESPECTIVE TUBE ELEMENTS OF THE HEAT EXCHANGE STRUCTURE WITH EACH FIN ELEMENT BEING CONNECTED AT ONE OF ITS EDGES TO A CORRESPONDING EDGE OF AN ADJACENT FIN ELEMENT AT ONE SIDE THEREOF AND AT ITS OPPOSITE EDGE TO THE CORRESPONDING EDGE OF THE ADJACENT FIN ELEMENT AT THE OTHER SIDE THEREOF, PROVIDING A GENERALLY CORRUGATED OR SERPENTINE SHAPED STRUCTURE, THE CONNECTING PORTIONS BETWEEN ADJACENT FIN ELEMENTS PROVIDING MEANS BY WHICH THE FIN ELEMENT MAY BE CONNECTED TO ASSOCIATED TUBE ELEMENTS OF THE HEAT EXCHANGE STRUCTURE, SAID METHOD COMPRISING THE STEPS OF FORMING A STRIP OF METAL INTO A GENERALLY CORRUGATED SHAPE, SIMULTANEOUSLY REDUCING AND TAPERING THE THICKNESS OF THE STRIP BY SQUEEZING AND COINING AT INTERMEDIATE PORTIONS OF THE FING ELEMENTS, WHEREBY THE LATTER GENERALLY TAPER IN THICKNESS FROM THEIR LATERAL EDGES TOWARD THE CENTRAL PORTION THEREOF, AND STRETCHING THE FIN ELEMENT AT SAID INTERMEDIATE PORTIONS OF REDUCED THICKNESS AS MAY BE NECESSARY TO PROVIDE SAID FIN STRUCTURE WITH FIN ELEMENTS OF UNIFORM WIDTH, GATHERING THE CORRUGATIONS TO BRING THE LATTER INTO CLOSER PROXIMITY THAN DESIRED IN THE FINISHED STRUCTURE, AND RELEASING THE CORRUGATIONS TO PERMIT EXPANSION THEREOF TO THE DESIRED SPACING.