Curved Base Air Filter

Patent metadata

Field	Value
Publication number	US-2025314222-A1
Application number	US-202519239696-A
Country	US
Kind code	A1
Filing date	Jun 16, 2025
Priority date	Dec 18, 2020
Publication date	Oct 9, 2025
Grant date	—

Abstract

An apparatus and methods are provided for an air cleaner to be mounted onto an air inlet of an internal combustion engine. The air cleaner comprises an air filter that includes a filter medium disposed between a curved base and a cover. The curved base provides an interface between the air filter and the air inlet, and comprises a shape that provides clearance between the curved base and an electric choke installed onto a carburetor comprising the air inlet. The cover secures the air filter and the curved base to the air inlet such that an airstream is drawn through the filter medium and is conducted into the air inlet. A raised portion of the cover is configured to cooperate with the curved base to ensure a desired volume of the airstream is available to the air inlet at substantially all engine speeds.

First claim

What is claimed is:

1 . An air cleaner to be mounted onto an air inlet of an internal combustion engine, comprising:
an air filter comprising a filter medium disposed between a first end cap and a second end cap; a curved base configured to provide an interface between the air filter and the air inlet; and a cover configured to secure the air filter and the curved base to the air inlet such that an airstream is drawn through the filter medium and is conducted into the air inlet.

2 . The air cleaner of claim 1 , wherein the curved base comprises a curved portion that extends radially from an inlet receiver configured to receive the air inlet to a peripheral flat portion that is configured to couple with the first end cap.

3 . The air cleaner of claim 2 , wherein the curved portion comprises a compound-curve cross-sectional shape that provides clearance between the curved base and an electric choke installed onto a carburetor comprising the air inlet.

4 . The air cleaner of claim 3 , wherein the compound-curve cross-sectional shape comprises a series of tangent curves, one or more of the tangent curves each comprising a unique radius of curvature.

5 . The air cleaner of claim 4 , wherein the compound-curve cross-sectional shape comprises at least a first radius of curvature adjacent to the inlet receiver, a second radius of curvature along the curved portion extending away from the inlet receiver, and a third radius of curvature adjacent to the peripheral flat portion.

6 . The air cleaner of claim 5 , wherein the second radius of curvature is greater than the first radius of curvature and the third radius of curvature, and the third radius of curvature is greater than the first radius of curvature.

7 . The air cleaner of claim 2 , wherein the peripheral flat portion comprises a horizontal surface that circumferentially surrounds the curved portion and is configured to directly contact an entirety of the first end cap so as to ensure that the airstream is drawn through the filter medium.

8 . The air cleaner of claim 1 , wherein the cover comprises a peripheral flat portion that is configured to couple with the second end cap and circumferentially surrounds a raised portion that is configured to provide a predetermined degree of clearance between the cover and the curved portion.

9 . The air cleaner of claim 8 , wherein the peripheral flat portion comprises a horizontal surface that is configured to directly contact an entirety of the second end cap so as to ensure that the airstream is drawn through the filter medium.

10 . The air cleaner of claim 8 , wherein the predetermined degree of clearance is configured to ensure a desired volume of the airstream is directed to the air inlet at substantially all engine speeds.

11 . The air cleaner of claim 1 , wherein the curved base comprises a first peripheral edge configured to retain the first end cap, and the cover comprises a second peripheral edge configured to retain the second end cap, the first and second peripheral edges being configured to retain the air filter between the curved base and the cover.

12 . The air cleaner of claim 1 , wherein a fastener is configured to retain the cover, the air filter, and the curved base fixedly installed onto the air inlet.

13 . The air cleaner of claim 12 , wherein the fastener comprises a thumb nut that may be hand-tightened onto a threaded stud extending from the air inlet through a hole disposed within a depression in the center of the cover.

14 . A method for an air cleaner to be mounted onto an air inlet of an internal combustion engine, comprising:
providing an air filter comprising a filter medium disposed between a first end cap and a second end cap; configuring a curved base comprising an interface between the air filter and the air inlet; and forming a cover to secure the air filter and the curved base to the air inlet such that an airstream is drawn through the filter medium and into the air inlet.

15 . The method of claim 14 , wherein configuring the curved base comprises extending a curved portion radially away from an inlet receiver to a peripheral flat portion that is configured to receive the first end cap, the inlet receiver configured to be coupled with the air inlet.

16 . The method of claim 15 , wherein configuring the curved base further comprises forming a compound-curved cross-sectional shape of the curved base to provide clearance between the curved base and an electric choke of a carburetor comprising the air inlet, the compound-curved cross-sectional shape comprising at least a first radius near the inlet receiver, a second radius extending away from the inlet receiver, and a third radius adjacent to the peripheral flat portion.

17 . The method of claim 16 , wherein configuring the curved base further comprises selecting the first radius, the second radius, and the third radius, such that the second radius is greater than the first radius and the third radius, and the third radius is greater than the first radius.

18 . The method of claim 14 , wherein forming the cover comprises forming a peripheral flat portion to couple with the second end cap and circumferentially surround a raised portion that provides a predetermined degree of clearance between the cover and the curved portion.

19 . The method of claim 18 , wherein forming the cover further comprises configuring the predetermined degree of clearance to ensure a desired volume of the airstream is directed to the air inlet at substantially all engine speeds.

Assignees

• K&N Eng Inc

Inventors

• Williams Steve
• Wall Jere James

Classifications

• F02M35/10196

  Carburetted engines · CPC title

• F02M35/044

  Special arrangements of cleaners in or with respect to the air intake system, e.g. in the intake plenum, in ducts or with respect to carburettors · CPC title

• F02M35/02483 Primary

  Cylindrical, conical, oval, spherical or the like filter elements; wounded filter elements · CPC title

• F02M35/02416

  Fixing, mounting, supporting or arranging filter elements; Filter element cartridges · CPC title

• F02M35/0204 Primary

  for connecting or joining to other devices, e.g. pipes · CPC title