Chemically bonded multi-wall conduit
AssigneeMarkel Corporation
InventorsKim A. Reynolds, Charles P. Marino
Life of this patent
Estimating the term…
Abstract
An improved conduit for transporting fuel and/or fuel vapor or a motion transmitting member in an automobile comprising an inner tube comprised of fluorocarbon polymeric material and having an inner surface for contacting and containing fluids or a motion transmitting member, and a chemically etched outer surface having a substantial portion of the fluorine of the fluorocarbon polymer substituted by a polar moiety. The conduit further includes an outer tube comprising an inner surface comprised of polymeric material containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of the inner tube and the inner surface of the outer tube prevents substantial relative separation of or movement between the inner and outer tubes.
Claims23
An improved fuel system conduit for transporting fuel and/or fuel vapor in an automobile comprising:
- (a) an inner tube comprising fluorocarbon polymeric material and having (i) an inner surface for contacting and containing the fuel and/or fuel vapor, said inner surface comprising a mixture of fluorocarbon polymeric material and semiconductive carbon;
- and (ii) a chemically etched outer surface having a substantial portion of the fluorine of said fluorocarbon polymer substituted by a polar moiety;
- and
- (b) an outer tube surrounding and coaxial with said inner tube, at least the inner surface of said outer tube comprising polymeric material containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of said inner tube and the inner surface of said outer tube prevents substantial relative movement between said inner and outer tubes.
An improved motion transmitting conduit comprising:
- (a) an inner tube comprising fluorocarbon polymeric material and having (i) an inner surface for contacting the motion transmitting means, and (ii) a chemically etched outer surface having a substantial portion of the fluorine of said fluorocarbon polymer substituted by a polar moiety;
- and
- (b) an outer tube surrounding and coaxial with said inner tube, at least the inner surface of said outer tube comprising polymeric material containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of said inner tube and the inner surface of said outer tube prevents substantial relative movement between said inner and outer tubes.
A method of producing an improved fuel system conduit comprising the steps of:
- (a) providing an inner tube comprising fluorocarbon polymeric material on the outer surface thereof;
- (b) providing a chemical etchant at a temperature of from about 120.degree. F. to about 145.degree. F.;
- (c) immersing the outer surface of said inner tube in said chemical etchant under conditions effective to replace a substantial portion of the fluorine atoms on the outer surface of said inner tube with a polar moiety;
- (d) removing excess etchant from said tube;
- and
- (e) extruding a polymeric material over said inner tube to produce an outer tube surrounding and coaxial with said inner tube, at least the inner surface of said outer tube containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of said inner tube and the inner surface of said outer tube prevents substantial relative movement between said inner and outer tubes.
Dependencies are inferred from the claim text.