US4013743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral grain solid propellant fabrication process
Assignee: Boeing North American Inc
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Filing: 1973-02-12
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Granted: 1977-03-22
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Expires: 1993-02-12
Abstract
Abstract A solid propellant motor is fabricated by spreading a propellant onto an uncured reinforced fabric tape to a uniform thickness and then partially curing the mass to a semi-rigid state. The semi-rigid blanket is then rolled with an air gap between the spirally wound layers. The final configuration of the motor is subsequently fully cured.
Inventors
- 👤 Thomas L. Blasche, Jr.
- 👤 Donald D. Kobbeman
- 👤 Boyce M. Corley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:31
CPC Classifications
F; F02; F02K; F02K9/00; F02K9/08; F02K9/10; F02K9/14; C; C06; C06B; C06B21/00; C06B21/0033; C06B21/0058; C06B45/00; F05; F05D; F05D2250/00; F05D2250/10; F05D2250/15; F05D2250/20; F05D2250/25
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
151 words
A method of fabricating a spirally wound, solid propellant motor grain with a support structure therein, the improvement comprising the steps of: spreading a layer of uncured solid propellant onto both sides of a support structure, said solid propellant being an ammonium perchlorate oxidized composition containing a binder system that cures at a relatively high temperature, said support structure being a flexible, uncured, reinforced fabric tape with a thermosetting resin binder thereon that cures at a relatively high temperature, partially curing said uncured solid propellant applied to both sides of said uncured flexible support structure to a gelled state, forming said partially cured solid propellant and support structure into a layered, longitudinally-extending, spirally-wrapped solid propellant motor configuration, said propellant and support structure forming longitudinally-extending, annular air spaces between said layers, and heating simultaneously said finally formed, partially cured solid propellant and said support structure to a fully cured, structurally rigid state.
Claim 2
Independent Claim
151 words
A method of fabricating a spirally wound, solid propellant motor grain with a support structure therein, the improvement comprising the steps of: spreading a layer of uncured solid propellant onto both sides of a support structure, said solid propellant being an ammonium perchlorate oxidized composition containing a binder system that cures at a relatively high temperature, said support structure being a flexible, uncured, reinforced fabric tape with a thermosetting resin binder thereon that cures at a relatively high temperature, partially curing said uncured solid propellant applied to both sides of said uncured flexible support structure to a gelled state, forming said partially cured solid propellant and support structure into a layered, longitudinally-extending, spirally-wrapped solid propellant motor configuration, said propellant and support structure forming longitudinally-extending, annular air spaces between said layers, and heating simultaneously said finally formed, partially cured solid propellant and said support structure to a fully cured, structurally rigid state.
Claim 3
Dependent Claim
52 words
The invention as set forth in claim 1 wherein said solid propellant ammonium perchlorate oxidized composition containing a binder is comprised of 80 percent ammonium perchlorate and 18 percent carboxy-terminated polybutadiene binder with a benzene carboxamide curative, and wherein said uncured, reinforced fabric tape with a thermo-setting resin is an epoxy-fiberglass tape.
Claim 4
Dependent Claim
74 words
The invention as set forth in claim 2 wherein said solid propellant on both sides of said support structure is partially cured to a gelled state for 12 hours ± 0.5 hour, at approximately 170° F, after which said gelled solid propellant on said support structure is spirally formed into a final grain configuration, said solid propellant and said support structure being simultaneously cured for 4 hours, ± 0.5 hour, at approximately 300° F.
Claim 5
Dependent Claim
29 words
The invention as set forth in claim 1 wherein said solid propellant binder system is selected from the group consisting of carboxy-terminated polybutadiene, polybutadiene acrylic acid, and polybutadiene acrylonitrile.
Claim 6
Dependent Claim
31 words
The invention as set forth in claim 1 wherein said thermosetting resin binder on said reinforced fabric tape is selected from the group consisting of epoxy, phenolic ureaformaldehyde, resorcinal, and polyacrylate.
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) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |