Method and apparatus for producing tube

An apparatus for continuously producing a tube comprising:

• a former (B) supported by a frame (9) in the manner of a cantilever for helically winding thereon a strip (3) of synthetic resin and unvulcanized rubber incorporating a vulcanizing agent to shape the strip (3) into a tubular body (4) and send the tubular body (4) toward a free end of said former (B),
• heating means (C1 and C2) for heat-treating the tubular body (4) to 170.degree. C. to 220.degree. C. during movement of said strip toward said free end,
• characterized in that said heating means (C1 and C2) are disposed at least inside and outside said former (B) extending along its length and constructed to heat the tubular body (4) from inside and outside to a temperature of from about 170.degree. C. to about 220.degree. C. for vulcanization thereof, said heating means comprising a nichrome wire heater (21) incorporated in a metal core (8) of the former (B),
• the former (B) including a plurality of feed rollers (11) helically arranged and retained by a plurality of retainers (12) secured to the metal core (8) and arranged from a supported end of the metal core toward a free end thereof,
• said retainers (12) being formed with recesses (13) for retaining said feed rollers (11) and are arranged from the supported end of the metal core (8) toward the free end thereof with the phase of each of the retainers (12) displaced by a specified angle (.theta.) from retainer to retainer, the retainers being securable to the metal core in the displaced positions, whereby the helical pitch of the feed rollers (11) is freely determinable, and
• a cooling water nozzle (6) disposed on one side of the heating means (C1) toward which the tubular body (4) is sent out to thereby cool the tubular body (4) immediately after the vulcanization heat treatment.