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US 7,516,534 B2Granted
Method for attaching a nut element to a metal structure
AssigneeStresswave, Inc.
InventorsEric T. Easterbrook, Milton Sigelmann, Michael Landy, Taeksun Nam
Life of this patent
Estimating the term…
Abstract
A method of installing fastening elements, and rivetless fasteners for use with the method. Rivetless nutplate fasteners are installed in metal structures by providing flush fit barrel shaped plug or bushing portions in a hole in the structure as defined by an edge wall. The barrel portion is acted upon axially, and expanded radially outward toward the edge wall of the hole, to provide an interference fit. The ends of the barrel portion are machined as desired for flushness. Also, a hole is installed as necessary. Rivetless nutplates are easily installed, and the installation enhances fatigue life of the hole surrounding the barrel of the nutplate.
Claims59
A method of attaching a nut element to a metal structure, said structure having obverse and reverse surfaces, said method comprising:
- (a) providing a selected hole of suitable size and shape through said metal structure from said obverse surface to said reverse surface, by (i) inspection and acceptance of sidewall portions of a pre-existing hole, to provide a selected hole, or (ii) enlargement or rework of a pre-existing hole to provide at least some new sidewall portions, to provide a selected hole, or (iii) if no hole exists, providing a new hole with new sidewall portions through said metal structure, to provide a selected hole;
- (b) providing a nutplate base having a deformable metal insert comprising a body portion, said deformable metal insert sized and configured for insertion adjacent at least some of said sidewall portions of said selected hole, said body portion having first and second ends and peripheral wall extending for a length between said first and second ends;
- (c) inserting said deformable metal insert into said selected hole without deforming said metal structure or said metal insert, so that the body portion extends at least partially into the selected hole and at least a portion of said peripheral wall of said metal insert is adjacent at least a portion of said sidewall of said selected hole;
- (d) after insertion, compressing the metal insert with opposing tools having primarily an axial force component to physically deform the metal insert sufficiently that it frictionally engages at least some of the sidewall portions of the selected hole and radially displaces at least some of the body portion of said metal insert, and radially displaces at least some of said metal structure, causing at least some of the sidewall portions of said selected hole to exert compressive forces against said metal insert to enhance fatigue life of the metal structure adjacent the body of said metal insert, and substantially fixing said metal insert within the selected hole;
- (e) providing a nut element;
- and
- (f) securing said nut element to said nutplate base.
4 more elements
A method of attaching a fastener to a metal structure, said structure having obverse and reverse surfaces, and wherein a selected hole is provided for attachment of said fastener, said selected hole defined by sidewall portions extending through said metal structure from said obverse surface to said reverse surface, said method comprising:
- (a) providing a selected hole of suitable size and shape through said metal structure from said obverse surface to said reverse surface, by (i) inspection and acceptance of sidewall portions of a pre-existing hole, to provide a selected hole, or (ii) enlargement or rework of a pre-existing hole to provide at least some new sidewall portions, to provide a selected hole, or (iii) if no hole exists, providing a new hole with new sidewall portions through said metal structure, to provide a selected hole;
- (b) providing a nutplate base having a physically deformable metal insert comprising a body portion, said physically deformable metal insert sized and configured for insertion adjacent at least some of said sidewall portions of said selected hole, said body portion having first and second ends and peripheral wall extending for a length between said first and second ends;
- (c) inserting said deformable metal insert into said selected hole so that the body portion extends at least partially within the selected hole and along at least a portion of said peripheral wall of said metal insert and is adjacent at least a portion of said sidewall of said selected hole;
- (d) after insertion, compressing the metal insert with opposing tools having primarily an axial force component to physically deform the metal insert sufficiently that it frictionally engages at least some of the sidewall portions of the selected hole and radially displaces least some of the body portion of said metal insert, and radially displaces at least some of said metal structure, causing at least some of the sidewall portions of said selected hole to exert compressive forces against said metal insert to enhance fatigue life of the metal structure adjacent the body of said metal insert, and substantially fixing said metal insert within the selected hole;
- (e) forming a working hole axially through said metal insert, said working hole extending through said metal insert from said first end to said second end of said metal insert.
- (f) providing a nut element;
- (g) providing a cage, said cage adapted for adjustably securing said nut element relative to said nutplate base;
- and
- (h) securing said nut element to said nutplate base by securely affixing said cage to said nutplate base.
6 more elements
A method of attaching a fastener to a metal structure, said structure having obverse and reverse surfaces, and wherein a selected hole is provided for attachment of said fastener, said selected hole defined by sidewall portions extending through said metal structure from said obverse portions surface to said reverse surface, said method comprising:
- (a) providing a selected hole of suitable size and shape through said metal structure from said obverse surface to said reverse surface, by (i) inspection and acceptance of sidewall portions of a pre-existing hole, to provide a selected hole, or (ii) enlargement or rework of a pre-existing hole to provide at least some new sidewall portions, to provide a selected hole, or (iii) if no hole exists, providing a new hole with new sidewall portions through said metal structure, to provide a selected hole;
- (b) providing a nutplate base having a physically deformable metal insert comprising a body portion, said physically deformable metal insert sized and configured for insertion adjacent at least some of said sidewall portions of said selected hole, said body portion having first and second ends and peripheral wall extending for a length between said first and second ends;
- (c) inserting said deformable metal insert into said selected hole so that the body portion extends at least partially within the selected hole and along at least a portion of said peripheral wall of said metal insert and is adjacent at least a portion of said sidewall of said selected hole;
- (d) after insertion, compressing the metal insert with opposing tools having primarily an axial force component to physically deform the metal insert sufficiently that it frictionally engages at least some of the sidewall portions of the selected hole and radially displaces least some of the body portion of said metal insert, and radially displaces at least some of said metal structure, causing at least some of the sidewall portions of said selected hole to exert compressive forces against said metal insert to enhance fatigue life of the metal structure adjacent the body of said metal insert, and substantially fixing said metal insert within the selected hole;
- (e) forming a working hole axially through said metal insert, said working hole extending through said metal insert from said first end to said second end of said metal insert, and forming a tubular body portion having interior sidewalls in said metal insert;
- (f) installing threads in said interior sidewall of said tubular body portion;
- (g) providing a nut element;
- (h) providing a cage, said cage adapted for adjustably securing said nut element relative to said nutplate base;
- and
- (i) securing said nut element to said nutplate base by securely affixing said cage to said nutplate base.
7 more elements
A method of attaching a fastener to a metal structure, said structure having obverse and reverse surfaces, and wherein a selected hole is provided for attachment of said fastener, said selected hole defined by sidewall portions extending through said metal structure from said obverse surface to said reverse surface, said method comprising:
- (a) providing a selected hole of suitable size and shape through said metal structure from said obverse surface to said reverse surface, by (i) inspection and acceptance of sidewall portions of a pre-existing hole, to provide a selected hole, or (ii) enlargement or rework of a pre-existing hole to provide at least some new sidewall portions, to provide a selected hole, or (iii) if no hole exists, providing a new hole with new sidewall portions through said metal structure, to provide a selected hole;
- (b) providing a nutplate base having a physically deformable metal insert comprising a body portion, said physically deformable metal insert sized and configured for insertion adjacent at least some of said sidewall portions of said selected hole, said body portion having first and second ends and peripheral wall extending for a length between said first and second ends;
- (c) inserting said deformable metal insert into said selected hole so that the body portion extends at least partially within the selected hole and along at least a portion of said peripheral wall of said metal insert and is adjacent at least a portion of said sidewall of said selected hole;
- (d) after insertion, compressing the metal insert with opposing tools having primarily an axial force component to physically deform the metal insert sufficiently that it frictionally engages at least some of the sidewall portions of the selected hole and radially displaces least some of the body portion of said metal insert, and radially displaces at least some of said metal structure, causing at least some of the sidewall portions of said selected hole to exert compressive forces against said metal insert to enhance fatigue life of the metal structure adjacent the body of said metal insert, and substantially fixing said metal insert within the selected hole;
- (e) forming a working hole axially through said metal insert, said working hole extending through said metal insert from said first end to said second end of said metal insert, and forming a tubular body portion having interior sidewalls in said metal insert;
- (f) installing threads in said interior sidewall of said cylindrical tubular body portion;
- (g) providing a nut element;
- (h) providing a cage, said cage adapted for adjustably securing said nut element relative to said nutplate base;
- and
- (i) securing said nut element to said nutplate base by securely affixing said cage to said nutplate base.
7 more elements
A method of attaching a fastener to a metal structure, said structure having obverse and reverse surfaces, and wherein a selected hole is provided for attachment of said fastener, said selected hole defined by sidewall portions extending through a portion of said metal structure located between said obverse surface and said reverse surface, said method comprising:
- (a) providing a selected hole of suitable size and shape in said metal structure between said obverse surface and said reverse surface, by (i) inspection and acceptance of sidewall portions of a pre-existing hole, to provide a selected hole, or (ii) enlargement or rework of a pre-existing hole to provide at least some new sidewall portions, to provide a selected hole, or (iii) if no hole exists, providing a new hole with new sidewall portions through a portion of said metal structure, to provide a selected hole;
- (b) providing a nutplate base having a physically deformable metal insert comprising a body portion, said physically deformable metal insert sized and configured for insertion adjacent at least some of said sidewall portions of said selected hole, said body portion having first and second ends and peripheral wall extending for a length between said first and second ends;
- (c) inserting said deformable metal insert into said selected hole without deforming said metal structure or said metal insert, so that the body portion extends at least partially within the selected hole and along at least a portion of said peripheral wall of said metal insert and is adjacent at least a portion of said sidewall of said selected hole;
- (d) after insertion, compressing the metal insert with opposing tools having primarily an axial force component to physically deform the metal insert sufficiently that it frictionally engages at least some of the sidewall portions of the selected hole and radially displaces at least some of the body portion of said metal insert, and radially displaces at least some of said metal structure, causing at least some of the sidewall portions of said selected hole to exert compressive forces against said metal insert to enhance fatigue life of the metal structure adjacent the body of said metal insert, and substantially fixing said metal insert within the selected hole;
- (e) providing a nut element;
- and
- (f) securing said nut element to said nutplate base.
4 more elements
Dependencies are inferred from the claim text.