feed rollers 36 driven by a gear box 37 having an input pulley 38 driven from a drive pulley 39 by a belt 40 the strip of material is thereby propelled along a helical path defined by the rollers 30 a leading edge of the strip may be directed by hand around the supporting rollers to assist in starting the formation of a helix thereafter the helical formation of the fabric will continue to be propelled around the supporting rollers 30 by the feed rollers 36 which as will be seen in fig1 extend through the arch of the frame 25 so as to engage at least one convolution of the helix if the cutting equipment 20 is employed to cut the strip into predetermined lengths it may be desirable to leave small portions of successive lengths attached so that the helix formed of the strip will in effect be continuous this avoids the necessity of guiding the leading edge of each length manually as the composite strip is thus formed into a helix contiguous edges of successive convolutions of the helix are joined so as to produce the tubular structure means for joining the edges is shown schematically as a sewing machine 41 which extends through the arch 25c of the.