Rotary mower blade sharpener

• US 6,786,806 B2
• Filed: 01/17/2003
• Issued: 09/07/2004
• Est. Priority Date: 01/17/2003
• Status: Expired due to Fees

• Current Assignee: Harold D. Maus Jr
• Original Assignee: Harold D. Maus Jr
• Inventors: Maus, Harold D. Jr.
• Primary Examiner(s): Hail, III, Joseph J.
• Assistant Examiner(s): OJINI, EZIAMARA ANTHONY
• Application Number:
  US10/345,982
• Publication Number:
  US 20040142645A1
• Time in Patent Office: 599 Days
• Field of Search: 451/141, 451/9, 451/138, 451/89, 451/403, 451/372, 451/421, 269/32, 269/27, 269/45, 269/56, 269/76, 269/902, 292/811
• US Class Current: 451/141
• CPC Class Codes: B24B 3/365 of rotary mower blades
• CPC Class Codes: Y10S 269/902 Work holder member with v-shaped notch or groove
• CPC Class Codes: Y10T 29/53961 with work-holder for assembly

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.

Claims

1. 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.

2. The sharpener holder according to claim 1, wherein a second clamping screw is provided from the housing frame'"'"'s bottom side to support the cradle and the rotary mower blade.

3. The sharpener holder according to claim 1, wherein a fastener is provided from the housing frame'"'"'s front side to attach said housing frame to said slidable bracket.

4. The sharpener holder according to claim 1, wherein an air pressure source is provided for the pneumatic cylinder.

5. The sharpener holder according to claim 1, wherein a main frame supports the two horizontal rails, said main frame having a pair of vertical angle iron ends and a pair of horizontal angle iron footings.

6. The sharpener holder according to claim 5, wherein an adjustable pneumatic valve is positioned on the main frame adjacent the pneumatic cylinder.

7. The sharpener holder according to claim 6, wherein the pneumatic valve is regulated in a range of 15 to 20 psi.

8. The sharpener holder according to claim 1, wherein one frame end has a rotatable acrylic shield adapted to partially cover the rotary grinder wheel.

9. The sharpener holder according to claim 1, wherein a rotatable semicylindrical acrylic shield is affixed to the upper rail on a separate tubular support proximate an end opposite to the end adjacent the grinder wheel.

10. The sharpener holder according to claim 9, wherein an on/off pneumatic valve is positioned on said tubular support for closing the pneumatic air pressure when said shield is rotated away from the mower blade.

11. The sharpener holder according to claim 1, wherein the pneumatic cylinder is a single-acting cylinder with approximately a four-inch stroke.