Patent Application
20060288673
The present invention relates to intake air filtration for an internal combustion engine, more specifically to air filtration for a velocity stack used in conjunction with a motorcycle engine carburetor.
Various methods are known for improving engine performance by increasing the amount of air-fuel mixture delivered to the engine combustion chambers. One method of maximizing the efficiency of moving the desired volume of air-fuel mix into the engine combustion chamber is to apply a velocity stack to the intake side of the carburetor. Performance is enhanced when the velocity stack is properly shaped and sized with respect to the carburetor throat area so that air flow is maximized. While velocity stacks have shown to increase engine performance, providing air filtration to the velocity stack with motorcycles has been problematic.
Typically air intake velocity stacks have been run open without filters, however this can create problems when particulate matter such as sand and dirt enter the engine. A simple mesh filter has been employed, however such mesh filters reduce the effect of cross-sectional area of the velocity stack and also tend to clog quickly, degrading engine performance. Furthermore, because many mesh filters are external to the velocity stack, they are visible and many motorcycle owners find them aesthetically objectionable.
To solve these problems, it is known to employ filtration devices within the velocity stack which avoids the problem of the external mesh filters and does not detract from the appearance of the motorcycle because the filter is not visible. An example of such a filter is disclosed in U.S. Pat. No. 6,824,583 entitled “Velocity Stack Air System for Motorcycles.” Another such device is disclosed in U.S. Pat. No. 5,868,808 issued to Henderson entitled “Velocity Stack Filter.” This document discloses a carburetor air intake velocity stack which includes a shaped mesh filter having an effective open area which exceeds the open area of the velocity stack by at least 50 percent. The filter is located within the air intake velocity stack and has a cylindrically formed flange which is trapped between the velocity stack and the carburetor. The Henderson filter is cone-shaped with the base of the cone positioned directly adjacent the carburetor intake opening. While the Henderson device increases the filtration surface area, it nonetheless does not utilize the greatest amount of filtration surface area possible inside the velocity stack.
It is therefore the object of the present invention to maximize air filtration within an internally concealed air filtration medium in a velocity stack. It is a further object of the invention to create a velocity stack air filtration assembly which is economical to produce and easy to maintain and install.
In order to meet these objectives, the present air filtration assembly has been devised. As described in greater detail below, the air filtration assembly provides a large frustoconical air filter which is attached to the mouth of the velocity stack with the larger base end of the air filter secured around the periphery of the inside wall of the velocity stack directly adjacent its opening. This places the air filter medium along the inside walls of the velocity stack throughout a substantial portion of its length. A funnel plate secures the filter to the body of the velocity stack and directs air into the center of the filter. With this configuration, the air filtration surface area is maximized while providing a concealed air filter assembly that does not detract from the aesthetic appearance of the velocity stack. When used on a motorcycle engine the velocity stack is preferably positioned out in the air stream facing forward so that a ram air effect is achieved. This pressurization of the intake air compensates for the air flow restriction imposed by the filter.
From the following drawings and description of the preferred embodiment, it will be appreciated by those of skill in the art that the objects of the invention have been achieved. While the present invention will be described with the reference to a specific embodiment, the following description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications to the present invention can be made to the preferred embodiment by those skilled in the art without departing from the true spirit and scope of the invention. It will be noted here that for better understanding like components are designated by the reference numerals throughout the various figures of drawing which follow.
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It should be understood that there may be other modifications and changes to the present invention that will be obvious to those of skill in the art from the foregoing description, however, the present invention should be limited only by the following claims and their legal equivalents.
