Process of and apparatus for making spirally corrugated rubber tubing using axially extensible helix

Claim 1

THE PROCESS OF MAKING A CORRUGATED RUBBER TUBE WHICH COMPRISES SUPPORTING AN ELONGATED RAW RUBBER TUBE BLANK IN SUBSTANTIALLY CYLINDRICAL FORM, POSITIONING ABOUT AND IN CIRCUMFERENTIALLY CONFINING RELATION TO THE SUPPORTED TUBE A RESILIENT HELICAL COIL FORMER, AXIALLY STRETCHING THE FORMER, TO SPACE ITS CONVOLUTIONS AXIALLY ALONG THE SUPPORTED TUBE, DISTENDING THE TUBE RADIALLY AND ENGAGING AND ASSEMBLING IT WITH THE STRETCHED FORMER TO PROVIDE AN ELONGATED ASSEMBLY OF THE TUBE AND THE FORMER IN WHICH PORTIONS OF THE TUBE LOCATED BETWEEN ADJACENT CONVOLUTIONS OF THE FORMER ARE BOWED OUTWARDLY AND CONSTITUTE EMBRYONIC CORRUGATIONS AND IN WHICH TENSION IN THE STRETCHED FORMER IMPARTS AXIAL FORCES TO THE DISTENDED TUBE AND TENDS TO SHORTEN THE ASSEMBLY AXIALLY, AUGMENTING SAID FORCES BY AN AXIAL THRUST APPLIED TO AT LEAST ONE END OF THE DISTENDED AND ENGAGED TUBE TO AXIALLY AND PROGRESSIVELY COLLAPSE THE ASSEMBLED TUBE AND FORMER SIMULTANEOUSLY AND IN UNISON WHILE THEY ARE SUPPORTED ON THE MANDREL TO DEVELOP SAID EMBRYONIC CORRUGATIONS INTO FULL CORRUGATIONS LOCATED BETWEEN THE CONVOLUTIONS OF THE HELICAL COIL FORMER, AXIALLY EXTENDING THE COLLAPSED TUBE TO WITHDRAW ITS CORRUGATIONS FROM BETWEEN THE CONVOLUTIONS OF THE FORMER, SEPARATING THE FORMER FROM THE TUBE, RECOLLAPSING AND REFORMING THE CORRUGATIONS IN THE TUBE AND TREATING THE RECOLLAPSED TUBE TO SET THE CORRUGATIONS.