Harvesters – Cutting – Housing or guard
Reexamination Certificate
2000-06-20
2002-10-22
Will, Thomas B. (Department: 3671)
Harvesters
Cutting
Housing or guard
Reexamination Certificate
active
06467247
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention pertains to agricultural equipment and, more particularly, to a rotary cutter and method of sharpening a rotary cutter blade.
Rotary cutters, sometimes referred to as bush hogs, are powered and pulled by tractors and are very useful for mowing and cutting grass, weeds, fields of clover, and severing and chopping shrubs, bushes, and other plants, as well as twigs, branches, and plant debris on farmland. Rotary cutters are hitched to a tractor. Rotary cutters can also have a wheel so that the rotary cutter can be more smoothly pulled by the tractor.
Rotary cutter blades are quite large and typically span 4-10 feet. Rotary cutter blades rotate and spin in a manner somewhat similar to a propeller, except in a horizontal direction generally parallel to the ground (soil). Conventional rotary cutters have solid housings about the tops and sides of the rotary cutter blades and have open bottoms so that the rotary cutter blades can contact and cut grass, weeds, shrubs, bushes, etc. on the farmland.
The edges of rotary cutter blades are required to be sharp in the direction of rotation to cut grass, weeds, shrubs, bushes, etc. Conventional rotary cutters only permit manual access and contact of rotary cutter blades from the bottom of the rotary cutter. Conventional rotary cutters are also very heavy, bulky and awkward.
Sharpening, maintaining or replacing rotary cutter blades in conventional rotary cutters are very cumbersome, tedious and labor intensive. After conventional rotary cutters are stopped, unhitched and disconnected from tractors, 2-5 strong farmers are typically required to turn each rotary cutter upside down. The rotary cutter assemblies can be disassembled with various tools so that the rotary cutter blades can be removed and placed in vices for sharpening by grinders.
After conventional rotary cutter blades have been sharpened, the rotary cutter assemblies are re-assembled, tightened, and re-connected to the housings so that each rotary cutter can be lifted and turned right side up by 2-5 strong farmers. Such manpower is not always available when it is necessary to sharpen, maintain, or replace the rotary cutter blades. The rotary cutters are then hitched and reconnected to the tractors. The preceding method is not only awkward, clumsy, and tedious, but it can be dangerous, harmful and injure farmers, such as if the heavy housings crush the farmer's foot, or the blades cut the farmer's hands or feet.
It is important to keep the rotary cutter blades sharp to be able to efficiently cut grass, weeds, shrubs, bushes, etc. Dull blades can be totally ineffective in cutting grass, weeds, shrubs, bushes, etc. When rotary cutter blades start becoming dull, the tractor must often be driven over the same patch of land numerous times to cut all the grass, weeds, shrubs, bushes, etc., in the path of the tractor. This requires more fuel for tractors and is wasteful, time-consuming and costly to farmers.
It is, therefore, desirable to provide an improved rotary cutter and method of sharpening rotary cutter blades which overcome most, if not all, of the preceding problems.
SUMMARY OF THE INVENTION
An improved rotary cutter assembly and method is provided to easily sharpen the rotary blade of the rotary cutter assembly without having to turn the rotary cutter assembly upside down. Advantageously, the special rotary cutter assembly and method is convenient, easy-to-use, and effective. Desirably, user-friendly the rotary cutter assembly enhances operator safety, fuel economy, and efficient cutting. The economical rotary cutter assembly and method also uses less manpower, decreases labor costs, lowers downtime, reduces turnaround time, and improves maintenance and operation of the rotary cutter assembly.
The rotary cutter assembly can be used with a tractor or machine in areas where one or more rotary blades are useful to cut grass, weeds, fields of clover, shrubs, bushes, and other plants. The rotary blade can be rotated by a rotary-blade shaft (output shaft) via a coupling of a drive shaft or hydraulic pump or motor of the tractor or machine. Preferably, the rotary cutter assembly has a housing providing a frame to cover the rotary blade in order to protect the operator from cuttings and flying debris during operation of the rotary blade, as well as to protect the rotary blade from rain and the environment. A wheel assembly can be operatively connected to the frame to help elevate the cutter blade above the ground as well as to facilitate wheeled transport (pulling or pushing) by the tractor or machine.
In order to facilitate sharpening of the rotary blade, the frame has an opening to permit access to the rotary blade. The opening could be in the side (peripheral skirt) of the frame to permit sidewise (lateral) access to the rotary blade, but is preferably in the top (cover) to permit downward access from above to the rotary blade. The opening is closed by a special door, which is locked, bolted, or otherwise fastened and secured to the frame during operation of the rotary and cutter assembly in order to block the access opening and prevent cuttings and flying debris from striking the operator during rotation of the rotary blade.
When it is desired to sharpen the blade, the rotary blade can be stopped, the rotary-blade shaft (output shaft) can be disconnected (decoupled) from the drive shaft, the frame can be unhitched (disconnected) from the tractor or machine, and the door (hatch) can be unfastened (unlocked). The door can then opened, such as with a doorknob or other handle, to permit access through the opening to the rotary blade. The rotary blade can be secured, such as with a clamp and safety cable or strap, to help prevent rotation and other movement of the rotary blade during sharpening. A grinder (grinding wheel), file, or other sharpening tool (instrument) can then be used to sharpen the rotary blade. The preceding procedure can be reversed after the rotary cutter blade has been sharpened in order to use the sharpened rotary blades of the rotary cutter assembly to cut grass, weeds, shrubs, bushes, plants, etc.
A more detailed explanation of the invention is provided in the following description and appended claims, taken in conjunction with the accompanying drawings
REFERENCES:
patent: 3657866 (1972-04-01), Burroughs
patent: 4147018 (1979-04-01), Valdespino
patent: 4378668 (1983-04-01), Gullett
patent: 4445312 (1984-05-01), Cartner
patent: 4466235 (1984-08-01), Cole
patent: 5237803 (1993-08-01), Domingue, Jr.
patent: 5657620 (1997-08-01), Thagard et al.
patent: 5765348 (1998-06-01), Thagard et al.
patent: 6178729 (2001-01-01), Vastag
Harrison Glenn
Harrison Thomas M.
Harrison Thomas M.
Mammen Nathan
Tolpin Thomas W.
Welsh & Katz Ltd.
Will Thomas B.
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