US4017959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming shrink-fit compression seal
Assignee: National Aeronautics and Space Administration
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Filing: 1976-04-01
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Granted: 1977-04-19
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Expires: 1996-04-01
Abstract
Abstract A method for making a glass-to-metal seal. A domed metal enclosure having a machined seal ring is fitted to a glass post machined to a slight taper and to a desired surface finish. The metal part is then heated by induction in a vacuum. As the metal part heats and expands relative to the glass post, the metal seal ring, possessing a higher coefficient of expansion than the glass post, slides down the tapered post. Upon cooling, the seal ring crushes against the glass post forming the seal. The method results in a glass-to-metal seal possessing extremely good leak resistance, while the parts are kept clean and free of contaminants.
Inventors
- 👤 with respect to an invention of Fletcher James C. Administrator of the National Aeronautics and Space Administration
- 👤 Ted J. Podgorski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:44
CPC Classifications
C; C03; C03C; C03C27/00; C03C27/02; B; B23; B23P; B23P11/00; B23P11/02; B23P11/025; Y; Y10; Y10S; Y10S29/00; Y10S29/035; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49863; Y10T29/49865; Y10T403/00; Y10T403/48
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
156 words
A method of making a noncontaminated glass-to-metal seal between a glass post and a metal enclosure having an opening therein, the periphery of the opening being a seal edge of controlled dimensions, comprising the steps of: shaping said glass post such that its cross section is in the shape of said opening and such that it is tapered along its length with the resulting smaller end being slightly smaller than said opening; and such that its surface has a desired surface finish; placing said shaped glass post in an upright position with said smaller end up; placing said opening of said metal enclosure over said small end of said post so that the metal enclosure is supported by said post; heating said metal enclosure thereby causing it to expand and slip down said post; and cooling said metal enclosure whereby the seal edge of said metal enclosure crushes against said glass post forming the desired seal.
Claim 2
Independent Claim
156 words
A method of making a noncontaminated glass-to-metal seal between a glass post and a metal enclosure having an opening therein, the periphery of the opening being a seal edge of controlled dimensions, comprising the steps of: shaping said glass post such that its cross section is in the shape of said opening and such that it is tapered along its length with the resulting smaller end being slightly smaller than said opening; and such that its surface has a desired surface finish; placing said shaped glass post in an upright position with said smaller end up; placing said opening of said metal enclosure over said small end of said post so that the metal enclosure is supported by said post; heating said metal enclosure thereby causing it to expand and slip down said post; and cooling said metal enclosure whereby the seal edge of said metal enclosure crushes against said glass post forming the desired seal.
Claim 3
Dependent Claim
34 words
A method according to claim 1 including the steps of shaping the periphery of said opening in the metal enclosure such that the width of said seal edge is between 0.002 and 0.006 inches.
Claim 4
Dependent Claim
53 words
a method according to claim 1 including the step of placing said metal enclosure and said glass post under vacuum then performing the steps of heating said metal enclosure and cooling said metal enclosure to form the desired seal then removing said metal enclosure in conjunction with said glass post from said vacuum.
Claim 5
Dependent Claim
24 words
A method according to claim 1 wherein said glass post is a fused quartz post and the metal enclosure is a domed niobium cylinder.
Claim 6
Dependent Claim
14 words
A method according to claim 1 wherein heating is obtained through an induction coil.
References Cited (Backward Citations)
US1331091A
Cited
GB550126A
Cited
US2768475A
Cited
FR1311323A
Cited
US3623196A
Cited
US3963327A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |