US 6,786,806 B2Granted

Rotary mower blade sharpener

OwnerHarold D. Maus, Jr.inventor

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Abstract

A mower blade sharpener apparatus has an automatic reciprocating holder means to sharpen lawn mower blades conveniently with any stationary circular flat-faced grindstone with its driving motor affixed to a common base. A housing frame having open opposing sides contains a blade holder with upper and lower securing clamps and a V-shaped cradle. The housing frame is attached by a screw to a carriage automatically moved back and forth a limited distance on a pair of parallel rods to sharpen the lawn mower blade. The housing frame and carriage are driven by a pneumatic system designed with a reciprocating movement of approximately 4 inches in a cycle duration of approximately a second. An on/off pneumatic valve switch automatically shuts off the pneumatic pressure when a semicylindrical shield which covers the blade portion not being sharpened is rotated back away from the blade.

Claims11

Dependent claims

A reciprocating rotary mower blade sharpener holder apparatus comprising:

a housing frame having an extended front side and a rear side, a top side, a bottom side, and partially open opposite sides for holding a rotary mower blade;
said housing frame having a first securing clamp positioned vertically from the topside thereof, and projecting into the housing frame for horizontally holding the rotary mower blade on a V-shaped cradle of a second securing clamp projecting into the housing frame from below the housing frame to maintain the blade position conducive to sharpening of a vertical blade edge;
two horizontal cylindrical rails aligned vertically;
said housing frame mounted on a bracket calibrated to reciprocate in a repeating cycle and slidable on said two horizontal cylindrical rails aligned vertically;
and
said bracket attached to an expansion segment of a pneumatic cylinder mounted horizontally, and aligned below and to a side of said rails;
whereby the secured rotary mower blade is sharpened automatically in a reciprocating movement by a stationary rotary grinder wheel with flat sharpening sides.

4 more elements

Dependencies are inferred from the claim text.