Method and apparatus for fabricating flexible tubing

Abstract

Abstract Flexible tubing is formed by preforming a helix, mounting the helix with its turns oriented in a predetermined manner, applying adhesive to the outer surface of the turns, and winding flexible sheet material around the helix to form an envelope over the helix skeleton. A multiplicity of layers of sheet material can be applied. In fabricating a circular duct, a helix of material of fixed cross-section is supported by a mandrel contacting the turns at spaced points as longitudinal bars spaced 120 degree. Adhesive is applied by an applicator contacting the outer face of the helix turns with a wiping or rolling contact through rotation of the mandrel or the applicator or both. A broad contact area, as afforded by a flattened outer face on each helix turn, sustains sufficient adhesive to penetrate superposed regions of an overlying thin, porous, flexible sheet wound on the helix and adhesively bond another layer of material wound thereover. Insulated tubing can have a plurality of wound layers of insulation in continuous sheet form with the single application of adhesive to the helical skeleton and a jacket to retain the outer layers. Tubing is produced on a multistation apparatus. A composite spacer rod and expandable mandrel shaft has a pivoted mounting end and an opposite end selectively coupled to a first station comprising a helix magazine and a spacer rod drive, to a second station comprising a mandrel drive and to a third station for packeting the assembled duct and unloading it from the mandrel shaft. A rack sustaining roll goods and the adhesive applicator for cooperative manipulation relative to the mandrel mounted helix is located at the second station.

Inventors

• 👤 J Helmick
• 👤 B Goebel
• 👤 J Current

Bibliographic Details