US3646791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for deforming a metal workpiece, for upsetting rivets, and for blind riveting
Assignee: Grumman Corp
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Filing: 1970-11-06
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Granted: 1972-03-07
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Expires: 1990-11-06
Abstract
Abstract Method and apparatus for deforming a metal workpiece, for upsetting rivets, and for blind riveting which is accomplished by passing a stress wave through the metal workpiece or rivet sufficient to render it momentarily plastic and simultaneously forming it. The apparatus is basically comprised of means for generating a stress wave and a stress wave focusing device or amplifier. In operation, a workpiece is placed in a die or shaping means. The stress wave amplifier is then arranged to direct or focus the stress wave to the metal workpiece. Next, a stress wave is generated and passed through the stress wave focusing device, imparting a momentary state of plasticity to the metal workpiece. The momentarily plastic metal workpiece is then formed or shaped as desired.
Inventors
- 👤 Basil P Leftheris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:13
CPC Classifications
B; B21; B21J; B21J15/00; B21J15/02; B21J15/04; B21J15/043; B21J15/10; B21J15/16; B21J15/24; Y; Y10; Y10T; Y10T29/00; Y10T29/51; Y10T29/5168; Y10T29/5171; Y10T29/5172; Y10T29/53; Y10T29/53704; Y10T29/53709; Y10T29/53717; Y10T29/53726; Y10T29/5373
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
191 words
A tool for setting blind rivets having a tubular body with a head and extending through the rivet hole of the work to be riveted. A stem extending through said tubular body, the diameter of part of said stem being greater than the inside diameter of said tubular body, said stem having a former which is drawn into the tail of said tubular body, said tool comprising: a. means for generating a stress wave; b. a stationary focusing means through which said stress wave propagates and is directed through said blind rivet to render the rivet momentarily plastic; and c. means for exerting a pressure on said stem counter to and simultaneous with the application of said stress wave through said blind rivet to draw said former into said tubular body, creating an interference between said stem and said tubular body and between said tubular body and the walls of said rivet hole and for forming a blind head on the tail of said tubular body and clinching the work, which pressure is of a magnitude sufficient only to form the rivet while the rivet is momentarily in the plastic state.
Claim 2
Dependent Claim
191 words
A tool for setting blind rivets having a tubular body with a head and extending through the rivet hole of the work to be riveted. A stem extending through said tubular body, the diameter of part of said stem being greater than the inside diameter of said tubular body, said stem having a former which is drawn into the tail of said tubular body, said tool comprising: a. means for generating a stress wave; b. a stationary focusing means through which said stress wave propagates and is directed through said blind rivet to render the rivet momentarily plastic; and c. means for exerting a pressure on said stem counter to and simultaneous with the application of said stress wave through said blind rivet to draw said former into said tubular body, creating an interference between said stem and said tubular body and between said tubular body and the walls of said rivet hole and for forming a blind head on the tail of said tubular body and clinching the work, which pressure is of a magnitude sufficient only to form the rivet while the rivet is momentarily in the plastic state.
Claim 3
Dependent Claim
75 words
A tool for setting blind rivets as defined, in claim 1 wherein the means for generating a stress wave comprises: a. an electromagnetic coil; b. an energy storage means dischargeable through said coil providing a pulse of limited duration; c. a first driver coupled to said coil; and d. means for establishing an electromagnetic field around said first driver whereby a stress wave is generated by the electromagnetic repulsion between the coil and said driver.
Claim 4
Dependent Claim
115 words
A tool for setting blind rivets as defined in claim 2 wherein the means for exerting a pressure on said stem comprises: a. a second driver coupled to said coil; b. means for establishing an electromagnetic field around said second driver to generate a pressure due to the electromagnetic repulsion between said electromagnetic field and said coil; and c. means for applying said pressure to said stem at the end opposite said former to draw said former into said tubular body creating an interference between said stem and said tubular body and the walls of said rivet hole and for forming a blind head on the tail of said tubular body and clinching the work.
Claim 5
Dependent Claim
33 words
A tool for setting blind rivets as defined in claim 3 wherein the means for establishing the electromagnetic fields in said first and second drivers comprises electromagnEtically coupling said drivers to said coil.
Claim 6
Dependent Claim
52 words
A tool for setting blind rivets as defined in claim 4 wherein the means for applying said pressure to said stem comprises: a. a shaft connected to said second driver and centrally passing through said tool; and b. means on said shaft for engaging the end of said stem opposite said former.
Claim 7
Dependent Claim
163 words
A tool for setting blind rivets as defined in claim 5 wherein the focusing means is a conically shaped mass coupled to the first driver and the various components of the tool are related by the formula: where: s the stress delivered to the metal workpiece at the small end of the focusing means; so the stress developed at the large end of the focusing means by the electromagnetic repulsion between the coil and the driver; Ro the radius of the large end of the focusing means; K the tangent of the angle described by the edge of the cone and the base of the cone: C the speed of sound in the material; A the time required for the particle velocity to reach a maximum; Ao the cross-sectional area of the large end of the focusing means, i.e., the base of the cone; A the cross-sectional area at the small end of the focusing means; xo the length of the focusing means.
Claim 8
Dependent Claim
152 words
A tool for setting blind rivets as defined in claim 5 wherein the focusing means is an exponentially shaped mass coupled to the first driver and the various components of the tool are related by the formula: where: s the stress delivered to the metal workpiece at the small end of the focusing means; so the stress developed at the large end of the focusing means by the electromagnetic repulsion between the coil and the driver; C the speed of sound in the material; tA the time required for the particle velocity to reach a maximum; Ao the cross-sectional area of the large end of the focusing means; A the cross-sectional area at the smaller end of the focusing means; n the number appearing in the exponent of the equation which governs the shape of the focusing means, i.e., A Ao e nxo, where Xo is the length of the focusing means.
References Cited (Backward Citations)
US2465144A
Cited
US3108325A
Cited
US3210509A
Cited
US3417456A
Cited
US3475628A
Cited
US3453463A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |