Coated threaded fasteners with coating-free crests
AssigneeNylok Fastener Corporation
InventorsRichard J. Duffy, Joseph R. Dudley
Life of this patent
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Abstract
A method for fabricating a threaded fastener having a discontinuous coating of a contaminant-inhibiting coating material. In a preferred embodiment, the threaded fastener is formed so as to provide a coated fastener with substantially coating-free crests. The article resulting from the fabrication method also forms a part of the present invention. The resulting threaded fasteners include electrically conductive portions, allowing use of the fasteners in fabricating structural assemblies using welding techniques.
Claims19
An externally threaded fastener that includes a screw thread with crests and roots, comprising:
- the screw thread with the exception of the crests, having a contaminant-inhibiting coating with a thickness sufficient to impede the deposition of subsequently-applied thread-interfering materials;
- and
- the crests being substantially coating-free, thereby providing a threaded fastener having a discontinuous coating and a conductive path between the fastener and an electrical source while retaining its ability to substantially impede the deposition of the thread-interfering materials.
An externally threaded fastener that includes a screw thread with crests and roots connected by flanks, comprising:
- the screw thread, with the exception of the crests, having a contaminant-inhibiting, fused powder coating with a thickness sufficient to impede the deposition of subsequently-applied thread-interfering materials:
- and
- the crests being substantially coating-free, thereby providing a threaded fastener having a discontinuous coating and a conductive path between the fastener and an electrical source while retaining its ability to substantially impede the deposition of the thread-interfering materials.
An externally threaded fastener that includes a screw thread with crests and roots connected by flanks, comprising:
- the screw thread, with the exception of the crests, having a contaminant-inhibiting coating applied in liquid form, the coating having a thickness sufficient to impede the deposition of subsequently-applied thread-interfering materials;
- and
- the crests being substantially coating-free, thereby providing a threaded fastener having a discontinuous coating and a conductive path between the fastener and an electrical source while retaining its ability to substantially impede the deposition of the thread-interfering materials.
A method of fabricating a fastener having a coating of a contaminant-inhibiting material, comprising the steps of:
- (a) providing a threaded fastener that includes a screw thread with crests and roots;
- (b) depositing a coating of the contaminant-inhibiting material on the screw thread of the fastener, the coating having a minimum thickness sufficient to impede the deposition of subsequently-applied thread-interfering materials;
- and
- (c) removing at least a portion of the coating from the crests to thereby form a discontinuously-coated fastener having substantially coating-free crests, wherein an electrically conductive path is provided between the fastener and an electrical source, and the fastener retains its ability to substantially impede the deposition of the thread-interfering materials.
A method of fabricating a threaded fastener having a discontinuous coating of a contaminant-inhibiting material, comprising the steps of:
- (a) providing a threaded fastener having an external threaded portion;
- (b) depositing a substantially continuous coating of the contaminant-inhibiting material on the threaded portion of the fastener, the coating having a minimum thickness sufficient to impede the deposition of subsequently-applied thread-interfering materials;
- and
- (c) removing the coating from a part of the external threaded portion to thereby provide a discontinuously-coated threaded fastener that retains its ability to substantially impede the deposition of the thread-interfering materials while providing a conductive path between the fastener threads and an electrical source.
A method of fabricating a threaded fastener having a discontinuous coating of a contaminant-inhibiting material sufficient to impede the deposition of subsequently-applied thread-interfering materials, comprising the steps of:
- (a) providing a threaded fastener that includes a screw thread with crests and roots;
- (b) heating the threaded fastener to a temperature sufficient to enable the contaminant-inhibiting coating to fuse and adhere to the threaded portion of the fastener;
- (c) depositing a substantially continuous coating of the contaminant-inhibiting material on the screw thread of the heated fastener;
- and
- (d) removing the coating from the crests to thereby provide a discontinuously-coated threaded fastener having substantially coating-free crests yet which retains its ability to substantially impede the deposition of the thread-interfering materials.
In a process for the fabrication of an article including the steps of assembling an externally threaded fastener to a structural member, performing an operation which deposits a thread-interfering contaminant material on the assembled structural member and fastener, and joining the structural member to a structure by engaging the fastener with a mating fastener, the threaded fastener including a screw thread with crests and roots, the improvement comprising performing the following steps on the fastener prior to assembly of the fastener to the structural member:
- supporting the fastener for treatment;
- forming a coating of the contaminant-inhibiting material on the screw thread of the fastener to thereby form a masked fastener that will impede deposition or retention of the subsequently applied thread-interfering material;
- removing the coating from the crests to thereby provide a discontinuously-coated threaded fastener having exposed, substantially coating-free crests;
- engaging the exposed crests with at least one welding electrode;
- joining the discontinuously-coated threaded fastener to the structural member by a welding technique;
- and
- joining the stuctural member to the structure by forming a threaded coupling between the discontinuously-coated threaded fastener and the mating fastener.
Dependencies are inferred from the claim text.