Trimmer line for string trimmers
AssigneeShakespeare Company
InventorDavid B Skinner
Life of this patent
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Abstract
A novel monofilament trimmer line is provided for reducing noise, reducing air drag and increasing durability by having a non-round cross-sectional shape defined as a polygon with three to six sides wherein the vertices between adjacent sides have been replaced with generous circular arcs, the arcs of a parabola, or even other arc shapes so long as the arc is convex and contains no sharp edges and wherein each arc is tangent to the two adjacent sides with a smooth and continuous transition, and the sides of the polygon are either straight or slightly convex, but not concave.
Claims12
A twist trimmer line for use with a powered rotary trimmer device comprising:
- a filament body having a non-circular cross-sectional shape comprising at least three distinct sides wherein each of the sides is convex, the filament body having a longitudinal axis,
- wherein the filament body further comprises vertices equal in number to the number of distinct sides, the vertices being located where adjacent distinct sides converge and comprising a convex arc contour, each convex arc contour forming a smooth and continuous convex transition with the sides adjacent thereto,
- wherein the cross-sectional shape has an area of from 2.92 to 4.34 mm2 and a diameter of a circle circumscribing the cross-sectional shape is from 1.2 mm to 4.5 mm,
- wherein the filament body is fixedly twisted about its longitudinal axis, such that each of the vertices follows a helical path along a length of the filament body, and
- wherein the filament body forms the twist trimmer line and is configured to cut vegetation when rotated in a powered rotary trimmer device.
Dependencies are inferred from the claim text.