Patent US3602978A successfully refreshed from Google Patents.
US3602978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming bimetallic transition joints
Assignee: United States Department of the Navy
•
Filing: 1969-04-14
•
Granted: 1971-09-07
•
Expires: 1989-04-14
Abstract
Abstract Transition joints formed of dissimilar metals, such as stainless steel and aluminum, are produced by assembling an aluminum rod and two stainless steel plugs coaxially within a stainless cylinder with the plugs positioned at each end of the rod. Both plugs are welded to the cylinder and the assembly is then heated and subjected to reduction by rotary swagging thus forming a metallurgical bond of the two metals. The assembly may be machined into tubular joints by standard techniques.
Inventors
- 👤 William D Oaks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:54
CPC Classifications
B; B23; B23K; B23K20/00; B23K20/22; B23K20/227; B23K20/2275
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
22 words
The method of claim 1 wherein: the reducing step is performed by rotary swagging until the desired amount of reduction is achieved.
Claim 2
Dependent Claim
20 words
The method of claim 2 wherein: the rods and plugs are machined to smooth close fitting surfaces prior to assembly.
Claim 3
Dependent Claim
25 words
The method of claim 2 wherein the welding step includes: making a continuous annular weld around each plug to join the plugs to the cylinder.
Claim 4
Dependent Claim
28 words
The method of claim 3 wherein the welding step includes: making a continuous annular weld around each plug at a position thereon which is spaced from the rod.
Claim 5
Independent Claim
186 words
A method of joining two metals having different coefficients of thermal expansion comprising: positioning a rod formed of a first metal within a cylinder which is formed of a second metal and is longer than said rod, positioning first and second plugs formed of said second metal at least partially within opposed ends of said cylinder and in abutting contact with said rod, welding each plug to said cylinder, and forming a metallurgical bond between said two metals by heating the assembled rod, plugs and cylinDer, and reducing the cross-sectional area of said assembly by 10 to 50 percent, cooling the assembly subsequent to the rotary swagging cutting away the original cylinder and the outer portion of the plugs so that the final diameter of the assembly is reduced to the final diameter of the rod, drilling an axial bore throughout the length of the assembly, and transversely cutting the drilled assembly at a position between the ends of the rod portion to thereby form two tubular transition joints each having tubular sections of dissimilar metals joined together by a metallurgical bond at a butt joint.
Claim 6
Independent Claim
218 words
A method of joining two metals having different coefficients of thermal expansion comprising: positioning a rod formed of a first metal within a cylinder which is formed of a second metal and is longer than said rod, positioning first and second plugs formed of said second metal at least partially within opposed ends of said cylinder and in abutting contact with said rod, welding each plug to said cylinder, and forming a metallurgical bond between said two metals by heating the assembled rod, plugs and cylinder, and reducing the cross-sectional area of said assembly by 10 to 50 percent, cooling the assembly subsequent to rotary swagging transversely cutting the assembly near the midpoint of the rod to make two sections, drilling an axial bore in one end of each section to a depth and diameter so as to remove all of the rod along a portion thereof less than one-half the length of the section, cutting away the second metal from the outer diameter of the other end of each section along a portion thereof which is less than one-half the length of the section and, drilling an axial bore through the sections to form two transition joints each having two tubular sections of dissimilar metals joined together by a lapjoint at which is formed a metallurgical bond.
References Cited (Backward Citations)
US1753638A
Cited
US2820751A
Cited
US3160951A
Cited
US3100742A
Cited
US3245140A
Cited
US3429025A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |