# US 5,341,849 A · Fuel system conduit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,341,849 A - Document ID: US5341849A - Status: Granted - Kind: A - Application number: 07/788,208 - Filed: 1991-11-05 - Granted: 1994-08-30 - Earliest claimed: 1991-11-05 - Assignees: Markel Corporation - Inventors: Warren Mang - Web page: https://patentgrep.com/patent/US5341849A ## CPC - F16L 11/081: {comprising one or more layers of a helically wound cord or wire (in combination with braided layers F16L11/088)} - F16L 11/10: with reinforcements not embedded in the wall (F16L11/11 takes precedence) - F16L 57/02: against cracking or buckling - Y10S 138/03: Polytetrafluoroethylene, i.e. PTFE - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract An improved fuel system conduit is disclosed. The fuel system conduits comprise an inner tubular liner and a substantially tubular cover comprising a metal band helically wrapped around said liner for covering and protecting the liner. The helical or spiral wrap allows fuel line flexibility while simultaneously inhibiting kinking. The helical wrap may also be covered by a plastic outer sheath. ## Claims ### Claim 1 An improved fuel system conduit for transporting fuel and/or fuel vapors in an automobile comprising: an inner tubular liner having a central chamber for contacting and containing the fuel and/or fuel vapor, said inner tubular liner comprising a thin-walled tubular liner, having a wall thickness of from about 5 to about 25 mils formed of fluorocarbon resin and having a circular cross sectional configuration; and a protective cover for said liner comprising: a metallic ribbon tightly wrapped in a helical configuration around said inner liner such that said inner liner is protected from kinking upon the application of bending stresses to said conduit, said ribbon having a generally rectangular cross-sectional configuration; and an outer plastic sheath substantially covering said metallic ribbon. ### Claim 2 (depends on 1) The improved conduit of claim 1 wherein said metallic ribbon comprises a carbon steel ribbon. ### Claim 3 (depends on 1) The improved conduit of claim 1 wherein said metallic ribbon has a width of from about 0.06 to about 0.2 inch and a thickness of from about 0.02 to about 0.04 inch. ### Claim 4 (depends on 1) The improved conduit of claim 1 wherein said inner tubular liner has an inner diameter of from about 0.3 to about 0.4 inch. ### Claim 5 (depends on 1) The improved conduit of claim 1 wherein said inner tubular liner has a wall thickness of from about 10 to about 20 mil. ### Claim 6 (depends on 1) The improved conduit of claim 1 wherein said outer sheath comprises polyamide. ### Claim 7 (depends on 1) The improved conduit of claim 1 wherein said inner liner has an interior layer of semi-conductive carbon. ### Claim 8 (depends on 1) The improved conduit of claim 1 wherein said inner tubular liner has a wall thickness of up to about 15 mil. ### Claim 9 An improved fuel system conduit for transporting fuel and/or fuel vapors in an automobile comprising: an inner tubular liner for contacting and containing the fuel and/or fuel vapor, said inner tubular liner comprising a thin walled tubular liner formed of fluorocarbon resin; and a protective cover for said liner comprising a metallic band wrapped in a tight helical configuration around said inner liner, said metallic band having a rectangular cross-sectional configuration. ### Claim 10 (depends on 9) The improved conduit of claim 9 wherein said inner tubular liner has a circular cross sectional configuration. ### Claim 11 (depends on 9) The improved conduit of claim 9 wherein said protective cover further comprises an outer plastic sheath substantially covering said metallic band. ### Claim 12 (depends on 9) The improved conduit of claim 9 wherein the thickness of said metallic band is from about 0.02 inch to about 0.04 inch. ### Claim 13 (depends on 12) The improved conduit of claim 12 wherein said ribbon comprises a carbon steel ribbon. ### Claim 14 (depends on 9) The fuel system conduit of claim 9 wherein said thin-walled tubular liner comprises a fluorocarbon resin selected from the group consisting of polytetrafluoroethylene, fluorinated ethylene propylene copolymer, perfluoroalkoxy resin, polychlortrifluoroethylene, ethylenetrichlortrifluoroethylene copolymer, ethylenetetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, and mixtures of two or more of these. ### Claim 15 (depends on 14) The conduit of claim 14 wherein said fluorocarbon resin comprises polytetrafluoroethylene. ### Claim 16 (depends on 15) The fuel conduit of claim 15 wherein said thin-walled tubular liner comprises an outer portion formed of polytetrafluoroethylene resin and an inner portion formed of a mixture of polytetrafluoroethylene resin and semi-conductive carbon. ### Claim 17 (depends on 9) The fuel conduit of claim 9 wherein said inner tubular liner has an inner diameter of from about 0.3 to about 0.4 inch and said metal band has a width of from about 0.1 to about 0.13 inch. ### Claim 18 (depends on 17) The fuel system conduit of claim 17 wherein the pitch of the windings of said metal band is about the inverse of the width of said metal band.