Rearwardly and downwardly-facing filter entrance for string trimmer
AssigneeMTD Products Inc
InventorsHartmut Kaesgen, Dennis Fowler
Life of this patent
Estimating the term…
Abstract
A string trimmer having the entrance to the air filter generally facing away from the forward direction of travel. Further, the filter intake is generally planar and is angled downwardly away from the plane normal to the direction of travel. The cross-sectional area of the filter intake is sized so as to reduce the velocity of air flowing through the filter intake.
Claims12
An apparatus including a frame mounted on a pair of wheels, said frame having a front end with respect to a forward direction of travel, cutting means adapted for cutting vegetation, an engine carried on said frame for providing power to drive said cutting means, and means for supplying air to said engine, wherein said engine has an associated engine air intake having a first cross-sectional area A1, and said air is supplied at a predetermined air volumetric flow rate, F, to define a constant first velocity V1, wherein V1=F/A1, the apparatus comprising:
- filtering means for filtering said air supplied to said engine, said filtering means including a generally planar filter air intake having an associated second cross-sectional area A2, wherein at said predetermined air volumetric flow rate F, A2 has a predetermined value so that the velocity, V2, of air passing through said filter air intake is less than V1, wherein V1-V2 is a predetermined amount, wherein said filter air intake is positioned downwardly with respect to a plane normal to said forward direction of travel.
An apparatus including a frame mounted on a pair of wheels, said frame having a front end with respect to a forward direction of travel, cutting means adapted for cutting vegetation, an engine carried on said frame for providing power to drive said cutting means, and means for supplying air to said engine, the apparatus comprising:
- filtering means for filtering said air supplied to said engine, said filtering means including a generally planar filter air intake having at least a minimal cross-sectional area effective to maintain a minimal volumetric air flow to said engine, wherein said filtering means is positioned relative to said frame so that said filter air intake generally faces away from said front end, wherein said filtering air intake is positioned downwardly.
In an apparatus including a frame mounted on a pair of wheels, said frame having a front end with respect to a forward direction of travel, cutting means adapted for cutting vegetation, an engine carried on said frame for providing power to drive said cutting means, and means for supplying air to said engine, a method for reducing engine failure due to overheating because of a clogged air filter, the method comprising the steps of:
- providing filtering means for filtering said air supplied to said engine, said filtering means including a generally planar filter air intake, said filtering air intake being positioned downwardly;
- and,
- positioning said filtering means relative to said frame so that said filter air intake generally faces away from said front end.
Dependencies are inferred from the claim text.