US3950157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ram air filter for light aircraft
Assignee: Individual
•
Filing: 1974-10-07
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Granted: 1976-04-13
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Expires: 1994-10-07
Abstract
Abstract A ram air filter for light aircraft comprising a parallelepiped housing and a replaceable filter element is disclosed. The housing comprises a base element and a cover element, which are injection molded of high impact plastic and are connected together in a snap-lock manner. The parallel faces of the base and cover elements include a plurality of ribs that define aligned apertures through which incoming air enters and leaves the housing. The ribs are formed such that they present a minimal amount of surface area to the incoming air stream during flight. A plurality of 90° locking studs attach the housing to the air intake channel of the aircraft's carburetor. The replaceable filter element is also parallelepiped in form and lies in the space defined by the housing so as to filter the air flowing through the aligned apertures. The replaceable filter element is formed of a compressible foam, preferably having a porosity grade lying in the range of 20-50 pores per linear inch.
Inventors
- 👤 Dorrance Henry Matney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:21
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/10; B01D39/00; B01D39/14; B01D39/16; B01D39/1669; B01D39/1676; Y; Y10; Y10S; Y10S55/00; Y10S55/31
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
355 words
A ram air filter for light aircraft comprising: 1. a paralleleipiped housing defined by right rectangular parallelgrams when viewed in two of its principal bisecting planes and a non-right parallelogram when viewed in the third of its principal bisecting planes, said parallelepiped housing comprising: a. a base element formed of high impact plastic, said base element including: an apertured main wall; a pair of opposed parallel side walls projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposite edges of said apertured main wall; and b. a cover element formed of high impact plastic, said cover element including: an apertured main wall; a pair of opposed parallel side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side lips at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assemblable together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements, said apertured main wall of said base element lying in a plane parallel to said apertured main wall of said cover element; and, 2. a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
Claim 2
Dependent Claim
355 words
A ram air filter for light aircraft comprising: 1. a paralleleipiped housing defined by right rectangular parallelgrams when viewed in two of its principal bisecting planes and a non-right parallelogram when viewed in the third of its principal bisecting planes, said parallelepiped housing comprising: a. a base element formed of high impact plastic, said base element including: an apertured main wall; a pair of opposed parallel side walls projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposite edges of said apertured main wall; and b. a cover element formed of high impact plastic, said cover element including: an apertured main wall; a pair of opposed parallel side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side lips at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assemblable together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements, said apertured main wall of said base element lying in a plane parallel to said apertured main wall of said cover element; and, 2. a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
Claim 3
Dependent Claim
85 words
A ram air filter as claimed in claim 1 wherein said acute end lip of said cover element lies against the outer surface of the obtuse end wall of said base element; and, including a projection projecting outwardly from the acute end wall of said base element and an aperture formed in the obtuse end lip of said cover element, said acute end lip and said obtuse end wall, and said projection and said aperture, co-acting to snap-lock said cover element to said base element.
Claim 4
Dependent Claim
291 words
A ram air filter for light aircraft comprising: 1. a housing comprising: a. a base element, said base element including: an apertured main wall; a pair of opposed parallel side walls projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposed edges of said apertured main wall; and, b. a cover element, said cover element including: an apertured main wall; a pair of opposed parallel side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side lips at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assembled together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements; and 2. a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
Claim 5
Dependent Claim
291 words
A ram air filter for light aircraft comprising: 1. a housing comprising: a. a base element, said base element including: an apertured main wall; a pair of opposed parallel side walls projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposed edges of said apertured main wall; and, b. a cover element, said cover element including: an apertured main wall; a pair of opposed parallel side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side lips at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assembled together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements; and 2. a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
Claim 6
Dependent Claim
85 words
A ram air filter as claimed in claim 3 wherein said acute end lip of said cover element lies against the outer surface of the obtuse end wall of said base element; and, including a projection projecting outwardly from the acute end wall of said base element and an aperture formed in the obtuse end lip of said cover element, said acute end lip and said obtuse end wall, and said projection and said aperture, co-acting to snap-lock said cover element to said base element.
Claim 7
Dependent Claim
280 words
A ram air filter for light aircraft comprising: 1. a parallelepiped housing, said parallelpiped housing defining right rectangular parallelograms when viewed in two of its principal bisecting planes and a non-right parallelogram when viewed in the third of its principal bisecting planes, said housing comprising: a. a base element including: an apertured main wall; a pair of opposed parallel sides projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls, at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposed edges of said apertured main wall; and, b. a cover element including: an apertured main wall; a pair of opposed side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assembled together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements; and,
Claim 8
Dependent Claim
280 words
A ram air filter for light aircraft comprising: 1. a parallelepiped housing, said parallelpiped housing defining right rectangular parallelograms when viewed in two of its principal bisecting planes and a non-right parallelogram when viewed in the third of its principal bisecting planes, said housing comprising: a. a base element including: an apertured main wall; a pair of opposed parallel sides projecting outwardly from one side of said apertured main wall; an obtuse end wall projecting outwardly from the same side of said apertured main wall as said side walls, at an obtuse angle; and, an acute end wall projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end walls projecting outwardly from opposed edges of said apertured main wall; and, b. a cover element including: an apertured main wall; a pair of opposed side lips projecting outwardly from one side of said apertured main wall; an obtuse end lip projecting outwardly from the same side of said apertured main wall as said side lips at an obtuse angle; and, an acute end lip projecting outwardly from the same side of said apertured main wall as said side walls at an acute angle, said obtuse and acute end lips projecting outwardly from opposed edges of said apertured main wall; c. said base and cover elements assembled together in a manner such that they define an enclosure through which air can flow by entering the enclosure through the apertured main wall of one of said base and cover elements and leaving said enclosure through the apertured main wall of the other of said base and cover elements; and,
Claim 9
Dependent Claim
35 words
a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
Claim 10
Dependent Claim
35 words
a filter element formed of a compressible foam material mounted in the enclosure defined by said base and cover elements and sized so as to substantially entirely fill said enclosure between said apertured main walls.
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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) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |