US3774291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Explosive bonding of tubes to fittings
Assignee: United States Department of the Air Force
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Filing: 1972-08-04
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Granted: 1973-11-27
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Expires: 1992-08-04
Abstract
Abstract A method of explosively joining tubes to fittings by first inserting the tube into a double tapered hole bored in the fitting and then positioning a close fitting wooden dowel having a charge of sheet explosive wrapped therearound in the tube under the tapered area. The double tapered cavity between the outer wall of the tube and the fitting is then evacuated by withdrawing the air therefrom and the explosive is detonated causing the tube to expand radially outward against the wall of the double tapered cavity producing a high integrity bond between the tube and the fitting.
Inventors
- 👤 J Snyder
- 👤 D Mclarty
- 👤 S Kenley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:48
CPC Classifications
B; B23; B23K; B23K20/00; B23K20/06; B23K20/08; B23K20/085; B21; B21D; B21D39/00; B21D39/04; B21D39/042; B21D39/06; B21D39/066; F; F28; F28F; F28F9/00; F28F9/02; F28F9/04; F28F9/16; F28F2275/00; F28F2275/06; F28F2275/068; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49373; Y10T29/49375; Y10T29/49805; Y10T29/49806
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
228 words
A method of joining a tube to a tubing fixture comprising the steps of: juxtapositioning a thick walled cylindrical tube protector beside the tube fitting such that central holes therethrough are axially aligned, the tube fitting having a double tapered cavity in the wall portion of its central hole; sealing the adjacent faces of the tube protector and the tube fitting to prevent air from passing therebetween; inserting the tube through the central hole in the tube fitting and into the tube protector, a portion of the tube protruding outwardly from the outer face of the fitting; inserting a close fitting dowel having a charge of sheet explosive wrapped therearound and covering the outer surface thereof, the dowel with sheet explosive attached being positioned under the double tapered cavity flush with the outer end of the tube; sealing the outer face of the tube fitting to prevent passage of air into the central hole; evacuating the air from the double tapered cavity in the inner wall of the tube fitting through the forward end of the central hole in the tube protector; and detonating the explosive charge through the outer seal to produce radial expansion of the tube against the wall of the evacuated double tapered cavity in the tube fitting and thereby produce a clean bonded joint of high integrity between the tube and the tube fitting.
Claim 2
Independent Claim
228 words
A method of joining a tube to a tubing fixture comprising the steps of: juxtapositioning a thick walled cylindrical tube protector beside the tube fitting such that central holes therethrough are axially aligned, the tube fitting having a double tapered cavity in the wall portion of its central hole; sealing the adjacent faces of the tube protector and the tube fitting to prevent air from passing therebetween; inserting the tube through the central hole in the tube fitting and into the tube protector, a portion of the tube protruding outwardly from the outer face of the fitting; inserting a close fitting dowel having a charge of sheet explosive wrapped therearound and covering the outer surface thereof, the dowel with sheet explosive attached being positioned under the double tapered cavity flush with the outer end of the tube; sealing the outer face of the tube fitting to prevent passage of air into the central hole; evacuating the air from the double tapered cavity in the inner wall of the tube fitting through the forward end of the central hole in the tube protector; and detonating the explosive charge through the outer seal to produce radial expansion of the tube against the wall of the evacuated double tapered cavity in the tube fitting and thereby produce a clean bonded joint of high integrity between the tube and the tube fitting.
Claim 3
Dependent Claim
63 words
A method according to claim 1 wherein the step of sealing the adjacent faces of the tube protector and tube fitting includes a groove of predetermined width and depth in the face of said tube protector and an O-ring positioned in said groove such that said O-ring makes pressure contact with the bottom of said groove and the surface of said tube fitting.
Claim 4
Dependent Claim
46 words
A method according to claim 1 wherein the step of sealing the outer surface of the tube fitting includes a sheet of polyvinylchloride film positioned over the outer exposed surface of the tube fitting covering the end of the tube and the explosive charge as well.
Claim 5
Dependent Claim
50 words
A method according to claim 1 wherein the step of detonating the explosive charge proceeds in the tube from the outer and toward the inner end such that the initial detonation operates to seal off the outer end of the tube to maintain the vacuum during the entire detonation process.
References Cited (Backward Citations)
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US3434194A
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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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |