Patent US3776466A successfully refreshed from Google Patents.
US3776466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyurethane foam insert for overexpanded rocket engine nozzles to prevent start transient sideloads
Assignee: Individual
•
Filing: 1973-01-19
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Granted: 1973-12-04
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Expires: 1993-01-19
Abstract
Abstract A polyurethane foam insert is adhesively secured within the nozzle of a regenerative cooled rocket engine. The insert has a central bore which reduces the engine throat to nozzle exit area ratio so as to prevent dangerous sideloads during normal or extended engine start transient periods at sea level conditions, but quickly erodes in a few seconds to permit normal engine operating conditions which follows the start transient period.
Inventors
- 👤 W Ray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:44
CPC Classifications
F; F02; F02K; F02K9/00; F02K9/97; F02K9/978; F02K9/974; Y; Y10; Y10S; Y10S60/00; Y10S60/909
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
81 words
In a rocket engine having a nozzle with an expansion ratio greater than required for a minimum sideload start, the improvement comprising: a temporary insert of plastic foam material secured within said rocket nozzle, said insert having an exterior side surface closely fitted to the interior side surface of said rocket nozzle, and having a central bore extending between its upper and lower ends which effectively reduces the expansion ratio of said nozzle to that required for a minimum sideload start.
Claim 2
Dependent Claim
81 words
In a rocket engine having a nozzle with an expansion ratio greater than required for a minimum sideload start, the improvement comprising: a temporary insert of plastic foam material secured within said rocket nozzle, said insert having an exterior side surface closely fitted to the interior side surface of said rocket nozzle, and having a central bore extending between its upper and lower ends which effectively reduces the expansion ratio of said nozzle to that required for a minimum sideload start.
Claim 3
Dependent Claim
18 words
In a rocket engine according to claim 1 wherein is said plastic foam material is rigid polyurethane foam.
Claim 4
Dependent Claim
27 words
In a rocket engine according to claim 2 wherein said polyurethane foam has a density approximately in the range of six to 10 pounds per cubic foot.
Claim 5
Dependent Claim
19 words
In a rocket engine according to claim 1 wherein said nozzle is of the cryogenic liquid regenerative cooled type.
Claim 6
Dependent Claim
117 words
In a regenerative cooled rocket engine having a nozzle with an expansion ratio greater than required for a minimum side-load start, the improvement comprising: a molded polyurethane foam insert having an exterior side surface adhesively secured to the inner side surface of said rocket nozzle, said insert having a central bore extending between its upper and lower ends, which bore is axially aligned with said rocket nozzle so as to effectively reduce the expansion ratio of said nozzle to that required for a minimum sideload start, and said polyurethane foam having a density which allows the insert to be totally eroded away in a few seconds when subjected to the hot exhaust gases of said rocket engine.
Claim 7
Dependent Claim
117 words
In a regenerative cooled rocket engine having a nozzle with an expansion ratio greater than required for a minimum side-load start, the improvement comprising: a molded polyurethane foam insert having an exterior side surface adhesively secured to the inner side surface of said rocket nozzle, said insert having a central bore extending between its upper and lower ends, which bore is axially aligned with said rocket nozzle so as to effectively reduce the expansion ratio of said nozzle to that required for a minimum sideload start, and said polyurethane foam having a density which allows the insert to be totally eroded away in a few seconds when subjected to the hot exhaust gases of said rocket engine.
Claim 8
Independent Claim
155 words
A method of obtaining minimum sideload starts in an overexpanded rocket nozzle, comprising: molding an insert for said engine nozzle from plastic foam material which will quickly erode away in a few seconds when subjected to the hot exhaust gases flowing in said rocket nozzle, said insert having a molded side exterior surface complementary to the side inner surface of said rocket nozzle, and a central bore extending between its upper and lower ends which is designed to reduce the expansion ratio of said rocket nozzle so as to give a minimum sideload start, coating the side exterior surface of said insert with an adhesive, placing said insert into said rocket nozzle whereby its bore is axially aligned with that of said nozzle and its side surface is in continuous contact with the side inner surface of said nozzle, and allowing said adhesive to glue said insert to the Side inner surface of said nozzle.
Claim 9
Independent Claim
155 words
A method of obtaining minimum sideload starts in an overexpanded rocket nozzle, comprising: molding an insert for said engine nozzle from plastic foam material which will quickly erode away in a few seconds when subjected to the hot exhaust gases flowing in said rocket nozzle, said insert having a molded side exterior surface complementary to the side inner surface of said rocket nozzle, and a central bore extending between its upper and lower ends which is designed to reduce the expansion ratio of said rocket nozzle so as to give a minimum sideload start, coating the side exterior surface of said insert with an adhesive, placing said insert into said rocket nozzle whereby its bore is axially aligned with that of said nozzle and its side surface is in continuous contact with the side inner surface of said nozzle, and allowing said adhesive to glue said insert to the Side inner surface of said nozzle.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |