Abstract: Tapered spiral tube in continuous lengths is fabricated with an alternating increasing and decreasing diameter, the length being severed at the locus of change. The taper may be straight, convex or concave, the tube being produced from strip-stock which is squeezed between biassing rollers whereby one or other edge is thinned, and as a consequence lengthened and convexly curved. The entire fabricating process is automatic, being predetermined by templet means and monitored by feed-back measures felt by the tube while being fabricated.
Abstract: Tapered spiral tube in continuous lengths is fabricated with an alternating increasing and decreasing diameter, the length being severed at the locus of change. The taper may be straight, convex or concave, the tube being produced from strip-stock which is squeezed between biassing rollers whereby one or other edge is thinned, and as a consequence lengthened and convexly curved. The entire fabricating process is automatic, being predetermined by templet means and monitored by feed-back measures felt by the tube while being fabricated.