Flexible tube

Claim 1

A FLEXIBLE SUBSTANTIALLY NONSHORTENING, SMOOTHBORED TUBE, COMPRISING: (A) A PLASTIC CHANNEL-SHAPED STRIP HAVING A SUBSTANTIALLY FLAT WEB PORTION AND A FLEXIBLE FLANGE ALONG EACH OF ITS LATERAL EDGES PROJECTING OUTWARDLY GENERALLY TRANSVERSE TO SAID WEB, EACH OF SAID FLANGES BEING ADAPTED TO FLEX ANGULARLY RELATIVE TO SAID WEB PORTION, (B) SAID STRIP BEING HELICALLY WOUND TO FORM A TUBE DEFINED BY THE EDGEWISE ABUTMENT OF THE WEB PORTIONS OF ADJACENT CONVOLUTIONS SUCH THAT THE ADJACENT FLANGES OF SAID CONVOLUTED STRIP PROJECT RADIALLY OUTWARDLY FROM SAID TUBE AND THE CONFRONTING SIDE FACES OF SAID FLANGES ARE CONTIGUOUS ALONG A HELICAL SEAM THEREBETWEEN, (C) AND SEALING MEANS EXTENDING IN A HELICAL PATH ALONG THE HELICAL SEAM BETWEEN THE CONVOLUTIONS OF SAID COILED STRIP LINKING THE RESPECTIVE ADJACENT FLANGES, (D) SAID SEALING MEANS COMPRISING A FLEXIBLE PLASTIC STRIP OVERLAPPING THE OUTER EDGES OF SAID ADJACENT FLANGES, JOINED TO THE OUTER SIDE FACES OF SAID FLANGES AND LEAVING THE CONTIGUOUS SIDE FACES OF SAID FLANGES FREE TO MOVE APART AT THEIR INNER ENDS, UPON THE APPLICATION OF TENSION TO SAID CONVOLUTED STRIP, TO PERMIT THE ADJACENT WEBS OF EACH CONVOLUTION OF SAID STRIP TO SEPARATE BY THE ANGULAR FLEXING OF SAID ADJACENT FLANGES WHILE MAINTAINING SAID CONVOLUTE TUBE FLUID TIGHT.