US4039308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filter
Assignee: Individual
•
Filing: 1975-09-10
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Granted: 1977-08-02
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Expires: 1995-09-10
Abstract
Abstract A rigid foam hemisphere attaches to the air inlet of cylindrical convex air rigid foam straightener and to internal combustion engine to define air filter therefor.
Inventors
- 👤 Edward Paul Schiff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:05
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1669; B01D39/1676; B01D46/00; B01D46/24; B01D46/2403; F; F02; F02M; F02M35/00; F02M35/02; F02M35/024
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
An apparatus for an air input of an internal combustion engine, comprising: porous air straightener of rigid foam, said air straightener having an input and an output end, said output end being smaller in diameter than said input end, said air straightener further having an interior surface which is a cylinder of revolution of a continuous curve defining a convex cylinder, said cylinder of revolution having a cross-sectional area which continuously decreases from said input end to said output end; and porous air cleaner of rigid foam closing the input end of said porous air straightener, said air cleaner further being of substantially hemispherical shape and an integral part with said air straightener; whereby the air flowing through said air cleaner and said air straightener is straightened before entering said air input.
Claim 2
Independent Claim
132 words
An apparatus for an air input of an internal combustion engine, comprising: porous air straightener of rigid foam, said air straightener having an input and an output end, said output end being smaller in diameter than said input end, said air straightener further having an interior surface which is a cylinder of revolution of a continuous curve defining a convex cylinder, said cylinder of revolution having a cross-sectional area which continuously decreases from said input end to said output end; and porous air cleaner of rigid foam closing the input end of said porous air straightener, said air cleaner further being of substantially hemispherical shape and an integral part with said air straightener; whereby the air flowing through said air cleaner and said air straightener is straightened before entering said air input.
Claim 3
Dependent Claim
28 words
An apparatus for an internal combustion engine according to claim 1 wherein surface of revolution of the porous air straightener is in the shape of a velocity stack.
Claim 4
Dependent Claim
41 words
An apparatus for an internal combustion engine according to claim 2 wherein said intake forming an interference fit with the output end of said velocity stack thereby coupling said air straightener and air cleaner to said air intake without a clamp.
Claim 5
Dependent Claim
26 words
An apparatus for an internal combustion engine according to claim 2 wherein the porous air straightener and air cleaner are made from a poly-vinyl chloride foam.
Claim 6
Dependent Claim
19 words
An apparatus for an internal combustion engine according to claim 4 wherein said continuous curve is a quarter elipse.
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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |