Patent US3988990A successfully refreshed from Google Patents.
US3988990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projectile
Assignee: United States Department of the Army
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Filing: 1975-09-03
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Granted: 1976-11-02
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Expires: 1995-09-03
Abstract
Abstract A projectile having a minimum of base drag effect and a maximum of velocitynd range during its operational flight, as caused by a controlled propellant gas discharge through a porous disc in the base of the projectile. A rearwardly exhausting propellant gas generator is ignited by a pressure sensitive igniter. The igniter is actuated by the porous disc which is slidably mounted in the rearward end of the projectile and responsive to a cartridge propelling charge.
Inventors
- 👤 Hugh D. MacDonald, Jr.
- 👤 Peter Tietz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:17
CPC Classifications
F; F42; F42B; F42B10/00; F42B10/32; F42B10/38; F42B10/40; F42B12/00; F42B12/02; F42B12/36; F42B12/38
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
76 words
A projectile comprising, a projectile body having a forward nose portion and a substantially cylindrical sidewall portion, a metallic slug substantially filling said forward nose portion, propellant gas generating means in said body rearward of said slug, a pressure sensative igniter in contact with said propellant gas generating means, and a porous disc slidably mounted in said body rearward of said igniter, said body sidewall portion having inwardly directed flange means at a rearmost end thereof.
Claim 2
Dependent Claim
76 words
A projectile comprising, a projectile body having a forward nose portion and a substantially cylindrical sidewall portion, a metallic slug substantially filling said forward nose portion, propellant gas generating means in said body rearward of said slug, a pressure sensative igniter in contact with said propellant gas generating means, and a porous disc slidably mounted in said body rearward of said igniter, said body sidewall portion having inwardly directed flange means at a rearmost end thereof.
Claim 3
Dependent Claim
28 words
The structure in accordance with claim 1 wherein said igniter is a cup-shaped member having a peripheral flange in contact with a forward surface of said porous disc.
Claim 4
Dependent Claim
31 words
The structure of claim 2 wherein said gas generating means includes extruded propellant surrounded by a cylindrical inhibitor, said inhibitor having a rearward surface in contact with said igniter peripheral flange.
Claim 5
Dependent Claim
14 words
The structure of claim 1 wherin said porous disc is of sintered tungsten material.
Claim 6
Dependent Claim
18 words
The structure of claim 4 wherin said igniter comprises a mix of lead styphnate and magnesium fluorocarbon material.
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) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |