Patent US3673287A successfully refreshed from Google Patents.
US3673287A
Expired / Lapsed
US
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Method of making cast-in -place end-burning propellant grains
Assignee: United States Department of the Army
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Filing: 1968-12-23
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Granted: 1972-06-27
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Expires: 1988-12-23
Abstract
Abstract An improved method of making cast-in-place end-burning propellant grains for rocket motors comprising the steps of applying a release agent to the rocket motor case insulation or rocket motor case, applying a liner/restrictor material over the release agent, casting the propellant directly inside the restrictor, curing the propellant and restrictor material to thereby bond the propellant directly to the restrictor whereby an end-burning propellant grain is formed in the restrictor adjacent the release agent which is adjacent the rocket motor case insulation or the rocket motor case of he rocket motor containing the cast-in-place end-burning propellant grain.
Inventors
- 👤 Charles E Thies
- 👤 Bernard L Thompson
- 👤 Stanley E Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:49
CPC Classifications
F; F02; F02K; F02K9/00; F02K9/08; F02K9/32; F02K9/34; F02K9/346; C; C06; C06B; C06B45/00; C06B45/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
27 words
The method of claim 1 and wherein said rocket motor case has insulation at the inside surface thereof and said release agent is applied to said insulation.
Claim 2
Dependent Claim
22 words
The method of claim 1 and wherein said release agent is seleCted from the release agents, consisting of polytetrafluoroethylene and silicone resins.
Claim 3
Dependent Claim
77 words
The method of claim 1 and wherein said restrictor material is selected from the restrictor materials consisting of cellulose acetate, ethylcellulose, butadiene-methylvinylpyridine copolymer, and styrene-butadiene rubber constituted of an emulsion polymerization product containing about 75 weight parts of butadiene and about 25 weight parts of styrene and wherein said restrictor material is applied in sufficient thickness to permit curing and bonding of the propellant directly to the restrictor material to thereby yield a substantially crack-free propellant grain.
Claim 4
Dependent Claim
94 words
The method of claim 1 and wherein said release agent is selected from the release agents consisting of polytetrafluoroethylene and silicone resins and wherein said restrictor material is selected from the restrictor materials consisting of cellulose acetate, ethylcellulose, butadiene-methylvinylpyridine copolymer, and styrene-butadiene rubber constituted of an emulsion polymerization product containing about 75 weight parts of butadiene and about 25 weight parts of styrene and wherein said restrictor material is applied in sufficient thickness to permit curing and bonding of the propellant directly to said restrictor material to thereby yield a substantially crack-free propellant grain.
Claim 5
Dependent Claim
19 words
The method of claim 4 and wherein said restrictor material is applied in a thickness of approximately one-eighth inch.
Claim 6
Dependent Claim
19 words
The method of claim 5 and wherein said restrictor material is applied in a thickness of approximately one-eighth inch.
Claim 7
Dependent Claim
94 words
The method of claim 2 and wherein said release agent is selected from the release agents consisting of polytetrafluoroethylene and silicone resins and wherein said restrictor material is selected from the restrictor materials consisting of cellulose acetate, ethylcellulose, butadiene-methylvinylpyridine copolymer, and styrene-butadiene rubber constituted of an emulsion polymerization product containing about 75 weight parts of butadiene and about 25 weight parts of styrene and wherein said restrictor material is applied in sufficient thickness to permit curing and bonding of the propellant directly to said restrictor material to thereby yield a substantially crack-free propellant grain.
Claim 8
Dependent Claim
19 words
The method of claim 8 and wherein said restrictor material is applied in a thickness of approximately one-eighth inch.
References Cited (Backward Citations)
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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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |