# US 2014/0196272 A1 · Method of isolating metallic fasteners in composite panels > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196272 A1 - Document ID: US20140196272A1 - Status: Published application - Kind: A1 - Application number: 13/741,420 - Filed: 2013-01-15 - Published: 2014-07-17 - Earliest claimed: 2013-01-15 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Paul E. Krajewski; Joseph M. Polewarczyk; Jeffrey L. Konchan; James C. O'Kane - Web page: https://patentgrep.com/patent/US20140196272A1 ## CPC - F16B 19/04: Rivets; Spigots or the like fastened by riveting (lead seals G09F3/00) - B21J 15/02: Riveting procedures - B21J 15/04: Riveting hollow rivets mechanically - B21J 15/147: {Composite articles} - B29C 65/562: {using extra joining elements, i.e. which are not integral with the parts to be joined (using plastic snap elements B29C65/58; using plastic rivets B29C65/601)} - B29C 65/602: {using hollow rivets (B29C65/607 takes precedence)} - B29C 66/1122: {Single lap to lap joints, i.e. overlap joints (B29C66/45, B29C66/472, B29C66/52272 take precedence)} - B29C 66/21: {said joint lines being formed by a single dot or dash or by several dots or dashes, i.e. spot joining or spot welding} - B29C 66/41: {Joining substantially flat articles (B29C66/47 and subgroups take precedence); Making flat seams in tubular or hollow articles (B29C66/51 and subgroups take precedence)} - B29C 66/7212: {characterised by the composition of the fibres} - B29C 66/73141: {Electrical conductivity} - B29L 2031/3055: {Cars} - F16B 5/04: by means of riveting (rivets F16B19/04) - Y10T 29/49956: Riveting - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) - B21J: FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES (rolling of metal B21B; making particular products by forging or pressing B21K; cladding or plating B23K; finishing surfaces by hammering B23P9/04; compacting surfaces by blasting with particulate material B24C1/10; general features of presses, presses for consolidating scrap B30B; furnaces in general F27) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method of isolating a metallic fastener from a carbon-fiber composite panel includes inserting the metallic fastener within an electrically isolating annular collar; inserting the metallic fastener and electrically isolating annular collar within a hole defined by the carbon-fiber composite panel; and securing the metallic fastener to the carbon-fiber composite panel. The annular collar may be circumferentially disposed about the metallic fastener such that the annular collar separates and electrically isolates the entire metallic fastener from the carbon-fiber composite panel. As such, the annular collar may minimize the galvanic reaction between the fastener and the carbon-fiber composite panel. ## Claims ### Claim 1 A method of isolating a metallic fastener from a carbon-fiber composite panel such that a galvanic reaction between the fastener and the carbon-fiber composite panel is minimized, the method comprising: inserting the metallic fastener within an electrically isolating annular collar such that the electrically isolating annular collar is circumferentially disposed about the metallic fastener; inserting the metallic fastener and electrically isolating annular collar within a hole defined by the carbon-fiber composite panel; and securing the metallic fastener to the carbon-fiber composite panel such that the annular collar separates and electrically isolates the entire metallic fastener from the carbon-fiber composite panel. ### Claim 2 (depends on 1) The method of claim 1, wherein the metallic fastener secures the composite panel to a second composite panel; and wherein the electrically isolating annular collar separates and electrically isolates the metallic fastener from the second carbon-fiber composite panel. ### Claim 3 (depends on 1) The method of claim 1, wherein the electrically isolating annular collar includes a nylon material, a polyvinyl chloride (PVC) material, or a Polytetrafluoroethylene (PTFE) material. ### Claim 4 (depends on 1) The method of claim 1, wherein the metallic fastener is a rivet. ### Claim 5 (depends on 4) The method of claim 4, wherein securing the metallic fastener to the carbon-fiber composite panel includes deforming a portion of the metallic fastener. ### Claim 6 (depends on 1) The method of claim 1, wherein securing the metallic fastener to the carbon-fiber composite panel includes deforming a portion of the electrically isolating annular collar. ### Claim 7 (depends on 1) The method of claim 1, wherein inserting the metallic fastener and electrically isolating annular collar within a hole defined by the carbon-fiber composite panel includes passing a portion of the metallic fastener and electrically isolating annular collar through the hole such that the portion protrudes from the carbon-fiber composite panel. ### Claim 8 A method of isolating a metallic fastener from a carbon-fiber composite panel such that the galvanic reaction between the fastener and the carbon-fiber composite panel is minimized, the method comprising: inserting the metallic fastener within an electrically isolating annular collar such that the electrically isolating annular collar is circumferentially disposed about the metallic fastener; inserting the metallic fastener and electrically isolating annular collar within a hole defined by the carbon-fiber composite panel; passing a portion of the metallic fastener and electrically isolating annular collar through the hole such that the portion is protruding from the carbon-fiber composite panel; and securing the protruding portion of the metallic fastener such that the protruding portion of metallic fastener is restrained from passing into the hole; and wherein the annular collar separates and electrically isolates the entire metallic fastener from the carbon-fiber composite panel. ### Claim 9 (depends on 8) The method of claim 8, wherein the metallic fastener secures the composite panel to a second composite panel; and wherein the electrically isolating annular collar separates and electrically isolates the metallic fastener from the second carbon-fiber composite panel. ### Claim 10 (depends on 8) The method of claim 8, wherein the electrically isolating annular collar includes a nylon material, a polyvinyl chloride (PVC) material, or a Polytetrafluoroethylene (PTFE) material. ### Claim 11 (depends on 8) The method of claim 8, wherein the metallic fastener is a rivet. ### Claim 12 (depends on 11) The method of claim 11, wherein securing the metallic fastener to the carbon-fiber composite panel includes deforming a portion of the metallic fastener. ### Claim 13 (depends on 8) The method of claim 8, wherein securing the metallic fastener to the carbon-fiber composite panel includes deforming a portion of the electrically isolating annular collar. ### Claim 14 An assembly comprising: a first carbon-fiber composite panel; a second carbon-fiber composite panel abutting the first carbon-fiber composite panel, the first and second carbon-fiber composite panels defining a common hole; an electrically isolating annular collar disposed within the hole and defining a central bore; a metallic fastener disposed within the central bore such that the electrically isolating annular collar is circumferentially disposed about the metallic fastener, the metallic fastener including: a head portion disposed adjacent to the first carbon-fiber composite panel; a deformable end portion disposed adjacent to the second carbon-fiber composite panel; and a body portion disposed within the hole. ### Claim 15 (depends on 14) The assembly of claim 14, wherein the electrically isolating annular collar separates and electrically isolates the entire metallic fastener from the carbon-fiber composite panel. ### Claim 16 (depends on 14) The assembly of claim 14, wherein the electrically isolating annular collar includes a nylon material, a polyvinyl chloride (PVC) material, or a Polytetrafluoroethylene (PTFE) material. ### Claim 17 (depends on 14) The assembly of claim 14, wherein the metallic fastener is a rivet.