Method of hose manufacture
AssigneeSchauenburg Hose Technology GmbH
InventorsMartin E Forrester, Ralf Jourdan
Life of this patent
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Abstract
A flexible, stretchable, crush resistant hose particularly well suited for supplying breathing gases to patients in medical applications and the like is formed by providing a helix of coils of thermoplastic material that are bonded to a web of thermoplastic material, preferably along inner diameter surface portions of the coils. The web extends radially outwardly from between adjacent coils to define a helical reverse-direction crease at a maximum outer diameter of the hose when the hose is in a normal minimal-length condition wherein the coils are situated side-by-side sandwiching portions of the web therebetween. The thermoplastic material of hose is stress relieved by an annealing process performed while the hose is axially compressed after the hose is formed.
Claims27
A method of forming a flexible, stretchable, crush resistant axially extending hose, comprising the steps of providing coils entirely of thermoplastic material to form a continuous helix of substantially constant diameter, providing a thin, narrow, elongate web of thermoplastic material that extends between adjacent coils of the helix and has edge regions welded to adjacent ones of the coils to form a single continuous wall with the web having a radially outwardly extending, centrally located fold situated between adjacent ones of the coils, and enhancing the flexibility of the hose by subjecting the hose to an annealing process while axially compressing the hose so that molecules of the thermoplastic material forming the coils of the helix and the thin elongate web are relaxed such that stress is substantially absent from the hose when the coils of the helix are close together.
A method of forming a flexible, stretchable, crush resistant, axially extending hose for supplying gases to patients in medical applications, comprising the steps of providing coils entirely of thermoplastic material that form a substantially uniform diameter helix, providing a thin web of thermoplastic material bonded to adjacent coils of the helix along inner diameter portions of the coils to form a single continuous wall and extending radially outwardly from between the adjacent coils to form a helical reverse-direction crease that defines a maximum outer diameter of the hose when the hose is in a normal condition wherein the coils are situated as closely together as possible, snugly sandwiching the material of the web therebetween, and subjecting the resulting hose to an annealing process to enhance the flexibility of the hose and to minimize the force needed to stretch the hose by axially compressing the hose during the annealing process so that molecules of the thermoplastic material forming the helical coils and forming the web are relaxed such that stress is substantially absent from the hose when the coils of the helix are closer together.
Dependencies are inferred from the claim text.