US4275285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of welding capped wheel nut
Assignee: Industrial and Automotive Fasteners Inc
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Filing: 1979-07-25
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Granted: 1981-06-23
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Expires: 1999-07-25
Abstract
Abstract A steel nut body has its wrench flats covered by a sheet stainless steel sheath that extends over one of the nut ends to form a cap. The surfaces of the wrench flats are formed with ridges that bear against the inner surfaces of the sheath. The sheath is welded to the nut to resist forces exerted during torquing by bringing a pair of electrodes into pressured contact with the sheath on opposed sides of the nut to produce pressure concentrations at the ridges. An extremely short, high current electrical pulse is then passed between the electrodes. The heating produced by the current at the interface between the sheath and the nut body decreases the electrical resistance of this path resulting in primary current flow path between the two interfaces, through the nut body, to produce resistance welds at the inner faces without substantially modifying the metallurgy of the sheath.
Inventors
- 👤 Albert A. Jadach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:43
CPC Classifications
F; F16; F16B; F16B37/00; F16B37/14; B; B23; B23K; B23K11/00; B23K11/16; B23K11/163
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
109 words
The method of forming a capped nut having a nut body with a central threaded aperture and polygonal sides, and a sheet metal cap adapted to at least partially surround the sides, comprising: bringing a pair of electrodes into pressured contact with opposed sides of the cap to impose opposed forces between the cap and the nut body, and passing a high current electrical pulse between the electrodes to cause a primary current flow through the contacting areas between the cap the the nut body adjacent the electrodes and through the nut body to cause welding of the cap to the nut body at the areas adjacent the electrodes.
Claim 2
Independent Claim
109 words
The method of forming a capped nut having a nut body with a central threaded aperture and polygonal sides, and a sheet metal cap adapted to at least partially surround the sides, comprising: bringing a pair of electrodes into pressured contact with opposed sides of the cap to impose opposed forces between the cap and the nut body, and passing a high current electrical pulse between the electrodes to cause a primary current flow through the contacting areas between the cap the the nut body adjacent the electrodes and through the nut body to cause welding of the cap to the nut body at the areas adjacent the electrodes.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the electrodes contact the cap at areas overlying opposed polygonal faces of the nut body.
Claim 4
Dependent Claim
63 words
The method of claim 2 wherein the polygonal faces of the nut body are formed with protuberances which abut the inner surfaces of the cap to form areas of pressure concentration with the abutting cap surfaces when the electrodes are pressed against the outer surfaces of the cap, whereby the welds are formed at the contact areas between the protuberances and the cap.
Claim 5
Dependent Claim
18 words
The method of claim 3 wherein the protuberances comprise generally axially extending ridges formed on the polygonal flats.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein the current flow exceeds 50,000 amperes and lasts for less than 30 microseconds.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein the nut body is formed of carbon steel and the cap is formed of stainless steel.
Claim 8
Dependent Claim
41 words
The method of claim 1 wherein the nut is a wheel nut having a conical end and the cap covers the end of the nut opposite to the conical end in addition to at least a portion of the wrench flats.
Claim 9
Dependent Claim
44 words
The method of claim 1 wherein the surfaces of the nut body are coated with a corrosion-resistant material and the high current electrical pulse breaks down the resistance of this material between contacting areas of the cap and the nut body adjacent the electrodes.
Claim 10
Independent Claim
118 words
The method of welding a sheet metal sheath to a nut body at least partially covered by the sheath, to form a capped wheel nut comprising: bringing a pair of electrodes into contact with spaced points on the outer surface of the sheath which overlies sections of the nut body and passing a short duration, high current pulse between the electrodes to cause a breakdown of the electrical resistance of the interfaces between the inner surface of the sheath and the contacted areas of the nut body, adjacent the electrodes, to provide a primary current path through these interfaces and the nut body between them resulting in welding of the sheath to the nut body at these interfaces.
Claim 11
Independent Claim
118 words
The method of welding a sheet metal sheath to a nut body at least partially covered by the sheath, to form a capped wheel nut comprising: bringing a pair of electrodes into contact with spaced points on the outer surface of the sheath which overlies sections of the nut body and passing a short duration, high current pulse between the electrodes to cause a breakdown of the electrical resistance of the interfaces between the inner surface of the sheath and the contacted areas of the nut body, adjacent the electrodes, to provide a primary current path through these interfaces and the nut body between them resulting in welding of the sheath to the nut body at these interfaces.
Claim 12
Dependent Claim
54 words
The method in claim 9 wherein the electrodes contact areas of the sheath overlying diametrically opposed wrench flats of the nut body and the wrench flats are formed with outwardly extending projections to produce pressure concentrations between the sheath and the nut body at these projections, so that the welding occurs at the projections.
Claim 13
Dependent Claim
37 words
The method of claim 10 wherein the nut body is coated with a corrosion-resistant material and the welding current pulse breaks down the resistance of the coating at the contacting areas of the projections and the sheath.
Claim 14
Dependent Claim
32 words
The method of claim 10 wherein the pressure concentrations between the projections and the sheath, produced by the forces applied to the sheath by the electrodes, exceed 1,000 pounds per square inch.
Claim 15
Dependent Claim
17 words
The method of claim 12 wherein the weld current has a duration of less than 30 microseconds.
Claim 16
Dependent Claim
13 words
The method of claim 13 wherein the weld current exceeds about 50,000 amperes.
Claim 17
Independent Claim
122 words
A method of forming a capped nut having a carbon steel nut body with a central threaded aperture and polygonal sides, and a stainless steel sheet metal cap adapted to at least partially surround the sides, comprising: bringing a pair of electrodes into pressured contact only with the opposed polygonal sides of the cap to impose opposed forces between the cap and the nut body, and creating primary current flow through the contacting areas between the cap and the nut body adjacent the electrodes and through the nut body to cause welding of the cap to the nut body at the areas adjacent the electrodes by the exclusive step of passing a high current electrical pulse of short duration between the electrodes.
Claim 18
Independent Claim
122 words
A method of forming a capped nut having a carbon steel nut body with a central threaded aperture and polygonal sides, and a stainless steel sheet metal cap adapted to at least partially surround the sides, comprising: bringing a pair of electrodes into pressured contact only with the opposed polygonal sides of the cap to impose opposed forces between the cap and the nut body, and creating primary current flow through the contacting areas between the cap and the nut body adjacent the electrodes and through the nut body to cause welding of the cap to the nut body at the areas adjacent the electrodes by the exclusive step of passing a high current electrical pulse of short duration between the electrodes.
Claim 19
Dependent Claim
63 words
The method of claim 15 wherein the polygonal faces of the nut body are formed with protuberances which abut the inner surface of the cap to form areas of pressure concentration with the abutting cap surfaces when the electrodes are pressed against the outer surfaces of the cap, whereby the welds are formed at the contact areas between the protuberances and the cap.
Claim 20
Dependent Claim
18 words
The method of claim 16 wherein the protuberances comprise generally axially extending ridges formed on the polygonal flats.
Claim 21
Dependent Claim
19 words
The method of claim 15 wherein the current flow exceeds 50,000 amperes and lasts for less than 30 microseconds.
Claim 22
Dependent Claim
44 words
The method of claim 15 wherein the surfaces of the nut body are coated with a corrosion-resistant material and the high current electrical pulse breaks down the resistance of this material between contacting areas of the cap and the nut body adjacent the electrodes.
Claim 23
Independent Claim
141 words
The method of welding a stainless steel metal sheath to a carbon steel nut body with polygonal sides at least partially covered by the sheath, to form a capped wheel nut comprising: bringing a pair of electrodes into pressure contact only with diametrically opposed spaced points on the outer surface of the sheath which overlies the polygonal sides of the nut body and passing a short duration, high current pulse between the electrodes to cause a breakdown of the electrical resistance of the interfaces between the inner surface of the sheath and the contacted areas of the nut body, adjacent the electrodes, to provide a primary current path through these interfaces and the nut body between them resulting in welding of the sheath to the nut body at these interfaces without requiring additional apparatus for displacing current through the nut body.
Claim 24
Independent Claim
141 words
The method of welding a stainless steel metal sheath to a carbon steel nut body with polygonal sides at least partially covered by the sheath, to form a capped wheel nut comprising: bringing a pair of electrodes into pressure contact only with diametrically opposed spaced points on the outer surface of the sheath which overlies the polygonal sides of the nut body and passing a short duration, high current pulse between the electrodes to cause a breakdown of the electrical resistance of the interfaces between the inner surface of the sheath and the contacted areas of the nut body, adjacent the electrodes, to provide a primary current path through these interfaces and the nut body between them resulting in welding of the sheath to the nut body at these interfaces without requiring additional apparatus for displacing current through the nut body.
Claim 25
Dependent Claim
37 words
The method of claim 20 wherein the polygonal sides are formed with outwardly extending projections to produce pressure concentrations between the sheath and the nut body at these projections, so that the welding occurs at the projections.
Claim 26
Dependent Claim
37 words
The method of claim 21 wherein the nut body is coated with a corrosion-resistant material and the welding current pulse breaks down the resistance of the coating at the contacting areas of the projections and the sheath.
Claim 27
Dependent Claim
32 words
The method of claim 21 wherein the pressure concentrations between the projections and the sheath, produced by the forces applied to the sheath by the electrodes, exceed 1,000 pounds per square inch.
Claim 28
Dependent Claim
17 words
The method of claim 20 wherein the weld current has a duration of less than 30 microseconds.
Claim 29
Dependent Claim
13 words
The method of claim 24 wherein the weld current exceeds about 50,000 amperes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |