# US 9,434,422 B2 · Geometric/mechanical isolation of aluminum to steel joining at trim edges for corrosion protection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,434,422 B2 - Document ID: US9434422B2 - Status: Granted - Kind: B2 - Application number: 14/195,898 - Filed: 2014-03-04 - Published: 2015-09-10 - Granted: 2016-09-06 - Earliest claimed: 2014-03-04 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Dragan B. Stojkovic; Colleen Marie Hoffman; Kimberly Ann Lazarz; Jack Lashbrook; Chris Verschaeve - Web page: https://patentgrep.com/patent/US9434422B2 ## CPC - B62D 27/023: {Assembly of structural joints} - B62D 27/065: {using screwthread (connection of crossbeam to A- pillars B62D25/147; mounting load bearing surfaces B62D21/09; securing mudguards B62D25/163; connections for synthetic parts B62D29/048)} - B62D 29/008: {predominantly of light alloys, e.g. extruded} - F16B 5/02: by means of fastening members using screw-thread ({F16B5/0004 takes precedence}; construction of screw-threaded connections F16B25/00 - F16B39/00) - F16B 33/008: {Corrosion preventing means} - Y10T 29/49622: Vehicular structural member making - Y10T 403/75: having a joining piece extending through aligned openings in plural members - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - 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) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A joint for a motor vehicle body comprises a first structural member fabricated from aluminum attached to a second structural member fabricated from steel. The second structural member has an adjoining portion that is in substantially juxtaposed abutting relation with the first structural member when the second structural member is attached to the first structural member. The second structural member has a ramp portion terminating in a bare exposed edge on the second structural member and upon which the bare exposed edge is disposed. The bare exposed edge is displaced from the first structural member to form a gap between the first structural member and the bare exposed edge to prevent corrosion of the bare exposed edge without the use of adhesives and sealants. ## Claims ### Claim 1 A joint for a motor vehicle body comprising a first structural member fabricated from aluminum attached to a second structural member fabricated from steel and wherein the second structural member is a hydroformed tube, wherein the second structural member has an adjoining portion that is in substantially juxtaposed abutting relation with the first structural member, wherein the second structural member is attached to the first structural member and the second structural member has a ramp portion terminating in a bare exposed edge on the second structural member and upon which the bare exposed edge is disposed, the bare exposed edge being displaced from the first structural member to form a gap between the first structural member and the bare exposed edge to prevent corrosion of the bare exposed edge without the use of adhesives and sealants. ### Claim 2 (depends on 1) The motor vehicle body joint of claim 1, wherein the first structural member is a component of a motor vehicle body. ### Claim 3 (depends on 1) The motor vehicle body joint of claim 1, wherein the bare exposed edge is disposed on a terminal portion of the ramp portion at a distal end of the hydroformed tube. ### Claim 4 (depends on 3) The motor vehicle body joint of claim 3, wherein the hydroformed tube comprises aluminized coated high strength steel and the bare exposed edge is formed by cutting the hydroformed tube prior to attachment to the first structural member. ### Claim 5 (depends on 1) The motor vehicle body joint of claim 1, wherein the second structural member comprises a pair of a hydroformed tubes and wherein each of the pair of hydroformed tubes has a ramp portion terminating in a bare exposed edge that forms a distal end of the each of the pair of hydroformed tubes of the second structural member, the ramp portion of each of the pair of hydroformed tubes having a terminal portion displaced from the first structural member to form a gap between the first structural member and each of the bare exposed edges to prevent corrosion of the bare exposed edge without the use of adhesives and sealants. ### Claim 6 (depends on 5) The motor vehicle body joint of claim 5, wherein the pair of hydroformed tubes each form a substantially rectangular cross-sectional tube and each further comprise an adjoining portion that is in substantially juxtaposed abutting relation with the first structural member when the second structural member is attached to the first structural member and wherein each of the pair of hydroformed tubes is arranged in substantially juxtaposed abutting relation one to the other proximate the adjoining portion of each the hydroformed tubes. ### Claim 7 (depends on 6) The motor vehicle body joint of claim 6, wherein the first and second structural members each have at least one opening in alignment with one another and through which a threaded fastener extends to attach the first structural member to the adjoining portion of the second structural member. ### Claim 8 (depends on 1) The motor vehicle body joint of claim 1, wherein the gap prevents water accumulation in the joint arising from capillary action. ### Claim 9 (depends on 8) The motor vehicle body joint of claim 8, wherein the gap is at least 3 mm. ### Claim 10 (depends on 1) The motor vehicle body joint of claim 1, wherein the first structural member has a substantially planar portion and the adjoining portion of the second structural member is substantially co-planar with the first structural member and wherein the ramped portion terminates with a terminal portion that places the bare exposed edge in parallel relationship with the first structural member. ### Claim 11 (depends on 1) The motor vehicle body joint of claim 1, wherein the hydroformed tube forms a substantially rectangular cross-sectional tube and wherein the bare exposed edge is formed by cutting the hydroformed tube at an oblique angle relative to the tube prior to attachment to the first structural member. ### Claim 12 (depends on 11) The motor vehicle body joint of claim 11, wherein the oblique angle is about 45 degrees. ### Claim 13 A joint comprising an aluminum member attached to a hydroformed tubular steel member in substantially juxtaposed abutting relation with the aluminum member, the steel member having a ramp portion terminating in a bare exposed edge, the bare exposed edge being displaced from the aluminum member to form a gap between the aluminum member and the bare exposed edge to prevent corrosion of the bare exposed edge without the use of adhesives and sealants. ### Claim 14 (depends on 13) The joint of claim 13, wherein said steel member further comprising aluminized coated high strength steel and wherein the bare exposed edge forms a distal end of the hydroformed tube and is formed by cutting the hydroformed tube prior to attachment to the aluminum member. ### Claim 15 (depends on 13) The joint of claim 13, wherein the ramp portion extends away from the aluminum member at an angle of at least 30 degrees. ### Claim 16 (depends on 13) The joint of claim 13, wherein the gap is at least 3 mm. ### Claim 17 (depends on 14) The joint of claim 14, wherein the hydroformed tube forms a substantially rectangular cross-sectional tube and wherein the bare exposed edge is formed by cutting the hydroformed tube at an oblique angle relative to the tube prior to attachment to the aluminum member. ### Claim 18 A method of forming a joint for a motor vehicle body, the method comprising the steps of: fabricating a first structural member from aluminum metal; fabricating a second structural member from steel metal having an adjoining portion and a ramp portion terminating in a bare exposed edge on the second structural member and upon which the bare exposed edge is disposed and wherein the second structural member is a hydroformed tube; and attaching the second structural member to the first structural member, wherein the adjoining portion of the second structural member is in substantially juxtaposed abutting relation with the first structural member when the second structural member is attached to the first structural member and the bare exposed edge is displaced from the first structural member to form a gap between the first structural member and the bare exposed edge to prevent corrosion of the bare exposed edge without the use of adhesives and sealants. ### Claim 19 (depends on 18) A method of claim 18, wherein said hydro formed tube forms a substantially rectangular cross-sectional tube, the method further comprising the step of forming the hydroformed tube with the ramp portion at a distal edge thereof, the ramp portion having a terminal portion upon which the bare exposed edge is disposed. ### Claim 20 (depends on 18) The method of claim 18, wherein the gap is at least 3 mm.