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US 6,640,414 B2Granted
Method for attaching metal members
AssigneeGeneral Motors Corporation
InventorsRobin Stevenson, Pei-Chung Wang
Life of this patent
Estimating the term…
Abstract
A method of attaching metal members, including placing the metal members in contact with each other and fastening them with a metal fastener having a central axis wherein the metal fastener includes an elongated portion having a substantially constant cross-sectional area at any cross-section taken along a length of the elongated portion perpendicular to the axis of the fastener and includes a topographically varying outer surface. The fastener is driven through the metal sheet and into the metal substrate during rotation of the fastener thereby inducing friction between the fastener, the sheet and the substrate for locally melting the members to form a flowable material that solidifies for attaching the members, the flowable material and the fastener together.
Claims18
A method of attaching metal members, comprising the steps of:
- (a) placing the metal members in contact with each other;
- (b) providing a metal fastener having a central axis wherein:
- i) the metal fastener includes an elongated portion extending from a bottom surface of a head portion of the fastener;
- and
- ii) the elongated portion includes a topographically varying outer surface for forming a plurality of inflection sites along the elongated portion;
- (c) rotating the metal fastener about the axis using a rotary driving apparatus;
- (d) driving the metal fastener through the metal members during rotation of the fastener thereby inducing friction between the fastener and the metal members for locally melting the members to form a flowable material that flows into at least one of the inflection sites of the fastener and wherein the fastener is driven only partially through one of the members;
- and
- (e) allowing the flowable material to solidify within the plurality of inflection sites for attaching the members, the flowable material and the fastener together wherein:
- i) the metal members are at least partially attached to each other with an interference fit created by the topographically varying outer surface of the elongated portion;
- and
- ii) the solidified flowable material directly metallurgically bonds the metal members to each other.
9 more elements
A method of attaching a metal sheet to a metal substrate for forming an automotive vehicle structure, comprising the steps of:
- (a) placing the metal sheet on the metal substrate such that a first surface of the sheet interfaces with a surface of the metal substrate, wherein the metal sheet and metal substrate are adapted for incorporation into an automotive vehicle;
- (b) providing a metal fastener having a central axis wherein:
- i) the metal fastener is formed of a material with a substantially higher melting point than the sheet and the substrate;
- ii) the metal fastener includes a top portion having a cavity formed in a top surface of the top portion;
- iii) the metal fastener includes an elongated portion extending from a bottom surface of the top portion to a flat leading surface, the elongated portion having a substantially constant cross-sectional area at any cross-section taken along a length of the elongated portion perpendicular to the axis of the fastener;
- and
- iv) the elongated portion is unthreaded and includes a topographically varying outer surface for forming a plurality of inflection sites along the length of the elongated portion;
- (c) rotating the metal fastener about the axis using a rotary driving apparatus that is adapted for temporarily mating engagement within the cavity in the top surface of the top portion of the fastener;
- and
- (d) driving the metal fastener through the metal sheet and into the metal substrate during rotation of the fastener thereby inducing friction between the fastener, the sheet and the substrate for locally melting portions of the sheet and substrate to form a flowable material that flows into the plurality of inflection sites of the fastener and wherein the fastener is driven only partially through the substrate;
- and
- (e) allowing the flowable material to solidify for integrally attaching the sheet, the substrate, the flowable material and the fastener together and for attaching the sheet to the substrate with a metallurgical bond.
9 more elements
A method of attaching a metal sheet to a metal substrate for forming an automotive vehicle structure, comprising the steps of:
- (a) placing the metal sheet on the metal substrate such that a first surface of the sheet interfaces with a surface of the metal substrate, wherein the metal sheet and metal substrate are adapted for incorporation into an automotive vehicle;
- (b) providing a metal fastener having a central axis wherein:
- i) the metal fastener is formed of a material with a substantially higher melting point than the sheet and the substrate;
- ii) the metal fastener includes a top portion having a cavity formed in a top surface of the top portion;
- iii) the metal fastener includes an elongated portion extending from a bottom surface of the top portion to a flat leading surface, the elongated portion having a substantially constant cross-sectional area at any cross-section taken along a length of the elongated portion perpendicular to the axis of the fastener;
- and
- iv) the elongated portion is unthreaded and includes a topographically varying outer surface for forming a plurality of inflection sites along the length of the elongated portion;
- (c) rotating the metal fastener about the axis using a rotary driving apparatus that is adapted for temporarily mating engagement within the cavity in the top surface of the top portion of the fastener;
- and
- (d) driving the metal fastener through the metal sheet and into the metal substrate during rotation of the fastener thereby inducing friction between the fastener, the sheet and the substrate for locally melting portions of the sheet and substrate to form a flowable material that flows into the plurality of inflection sites of the fastener and wherein the fastener is driven only partially through the substrate;
- and
- (e) allowing the flowable material to solidify for integrally attaching the sheet, the substrate, the flowable material and the fastener together and for attaching the sheet to the substrate with a metallurgical bond wherein:
- i) the sheet and the substrate are at least partially attached to each other with an interference fit created by the topographically varying outer surface of the elongated portion;
- and
- ii) the solidified flowable material directly metallurgically bonds the sheet and the substrate to each other.
12 more elements
Dependencies are inferred from the claim text.