US3811940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency heating method for vapor deposition of coatings onto filaments
Assignee: RTX Corp
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Filing: 1972-02-10
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Granted: 1974-05-21
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Expires: 1992-02-10
Abstract
Abstract A method for the pyrolytic deposition of a coating on a filament axially moving through a pyrolytic vapor deposition chamber comprising establishing a radio frequency electric field to heat a selected length of the filament and cause deposition thereon and regulating the density of the electric field to maintain a temperature profile of desired uniformity along the selected length.
Inventors
- 👤 F Douglas
- 👤 T Gregory
- 👤 R Stielau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:08
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/46; C23C16/54; C23C16/545; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2916; Y10T428/2918; Y10T428/2933; Y10T428/294; Y10T428/2958
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
A method for the pyrolytic deposition of a coating upon a filament comprising: axially passing the filament through a pyrolytic vapor deposition chamber and at least two coaxial cavity coupling means; establishing a radio frequency electric field of variable density in said deposition chamber by applying radio frequency power through each of said coupling means to cause current flow in the filament, said filament having sufficient resistance to dissipate the applied power to cause heating of a selected length of the filament and deposition thereon as it passes through said deposition chamber; and regulating the density of said electric field by tuning the plural cavity coupling means to maintain a substantially uniform temperature profile along said length.
Claim 2
Dependent Claim
60 words
The method according to claim 2 wherein the electric field of variable density is established by generating a radio frequency electric current by at least two power source means, each of said power source means being electrically connected to one of said coaxial cavity coupling means so as to provide a separate radio frequency electric current to each coupling means.
Claim 3
Dependent Claim
24 words
The method according to claim 3 wherein each of said coaxial cavity coupling means comprises a tuneable coaxial cavity coupler one quarter wavelength long.
Claim 4
Dependent Claim
50 words
The method according to claim 4 wherein the density of the radio frequency electric field is regulated by varying the distance and phasing between the cavities, impedance matching each coupler to its power source means and the filament, and tuning each coupler to the frequency of its power source means.
Claim 5
Dependent Claim
34 words
The method according to claim 5 wherein the coating being pyrolytically deposited is boron and the selected length of filament is heated to within the range of 1,000* to 1,300*C + or - 50*C.
Claim 6
Dependent Claim
11 words
The method according to claim 6 wherein the filament is tungsten.
Claim 7
Dependent Claim
11 words
The method according to claim 6 wherein the filament is carbon.
Claim 8
Dependent Claim
33 words
The method of claim 5 wherein the coating being pyrolytically deposited is aluminum oxide and the selected length of filament is heated within the range of 1,000* to 1,300*C + or - 50*C.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |