US 2003/0118419 A1Published application

Method for installation of nut plates, plugs, and bushings, and enhanced fatigue life metal structures resulting therefrom

AssigneeStresswave, Inc.

InventorsEric T. Easterbrook, Milton Sigelmann, Michael Landy, Taeksun Nam

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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.

Claims56

Dependent claims

A method for providing, removing, repairing, or repositioning a hole in a metal structure, said structure having obverse and reverse surfaces, and wherein said hole is defined by sidewall portions extending through said structure from said obverse to said reverse surface of the structure, said method comprising the steps of:

(a) providing a selected hole of suitable size and shape through said 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 to provide a selected hole;
(b) providing a physically deformable metal insert having a body portion, said physically deformable metal insert being sized and configured so as to be capable of frictionally engaging the 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 to permit the body portion to be inserted at least partially within the selected hole;
(c) inserting said deformable metal insert into said selected hole so that the body portion extends at least partially within the selected hole and said peripheral wall of said insert is adjacent at least a portion of said sidewall of said hole;
(d) after insertion, subjecting the insert to physical deforming forces to cause the insert to be deformed and to frictionally engage at least some of the sidewall portions of the selected hole, and to cause at least a portion of the body portion of said insert to be radially displaced and at least some of said metal structure to be radially displaced sufficient to cause at least some of the sidewall portions of said selected hole to exert compressive forces against said insert to a degree sufficient to enhance fatigue life of the hole surrounding said insert and to substantially fix said insert within said selected hole.

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 structure from said obverse to said reverse surface of the structure, said method comprising the steps of:

(a) providing a selected hole of suitable size and shape through said 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 having a body portion, said physically deformable metal insert being sized and configured so as to be capable of frictionally engaging the 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 to permit the body portion to be inserted at least partially within the selected hole;
(c) inserting said deformable metal insert into said selected hole so that the body portion extends at least partially within the selected hole and said peripheral wall of said insert is adjacent at least a portion of said sidewall of said hole;
(d) after insertion, subjecting the insert to physical deforming forces so as to cause the insert to be deformed and frictionally engage at least some of the sidewall portions of the selected hole, and to cause at least some of the body portion of said insert to be radially displaced and at least some of said metal structure to be radially displaced sufficient to cause at least some of the sidewall portions of said selected hole to exert compressive forces against said insert to a degree sufficient to enhance fatigue life of the hole surrounding the body of said insert and to substantially fix said insert within the selected hole;
(e) providing a nut element;
(f) securing said nut element to said nut plate base.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/305,469Filed 25 Nov 2002
Priority: 25 Nov 2001
Published: 26 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

B21J 15/50
Accessories for use in connection with riveting, e.g. pliers for upsetting; Hand tools for riveting: removing or cutting devices for rivets
B21J 15/02
Riveting: riveting procedures
B21J 15/04
Riveting procedures: riveting hollow rivets mechanically
B21K 25/00
Uniting components to form integral members