Harvesters – Motorized harvester – Including cutter yieldably mounted on its drive means
Reexamination Certificate
1999-10-21
2002-03-19
Novosad, Christopher J. (Department: 3671)
Harvesters
Motorized harvester
Including cutter yieldably mounted on its drive means
C172S045000
Reexamination Certificate
active
06357214
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to apparatus for dethatching a lawn.
Thatch is a mat of undecomposed plant material, consisting mainly of grass clippings, accumulated next to the soil in a lawn. Excessive thatch is undesired, since it chokes the roots of the grass, restricts exposure of the soil to the atmosphere, and causes run-off of water away from the soil. At present, thatch is often removed by raking and collecting the raked material. However, thatch is typically well embedded in a lawn and requires a large, time-consuming effort to be raked. “Walk behind” gas-powered dethatchers have been developed in the prior art to case the dethatching process. The prior art dethatchers, however, suffer from several drawbacks. First, the dethatchers are built for professional landscapers who need to regularly dethatch lawns, and, therefore, require a fast and efficient tool to accomplish the task. As such, the prior art dethatchers are built to professional standards, having size and power much greater than that needed for a homeowner, and at a relatively high expense. The high cost of the prior art dethatchers cannot be justified by the typical homeowner who will dethatch his lawn once or twice a year. Second, the prior art dethatchers utilize a completely metallic structure for extracting the thatch from a lawn. In particular, metallic claws or coils extend from a cylindrical, rotating housing, which are systematically passed into the grass to “kick up” the thatch. The loosened thatch is collected either by raking or blowing and properly disposed of. Unfortunately, the claws and coils are often damaged by hidden rocks, roots, etc. or tangled up with thatch material to completely loose effectiveness. As such, the claws and coils must be removed and either replaced by substitute parts or cleaned. Such removal, however, requires tools, such as an Allen wrench, box wrench, a screwdriver, etc. and a time-consuming effort.
It is an object to the subject invention to provide a dethatcher which uses a flexible filament.
It is also an object to the subject invention to provide a dethatcher which allows for quick and easy replacement of the dethatching elements.
SUMMARY OF THE INVENTION
The aforementioned objects are met by a dethatcher which utilizes a flexible filament, such as a nylon trimmer line typically used which rotating trimmers and edgers. Additionally, the subject invention utilizes a clamping mechanism which allows for the attachment of flexible filament without additional tools.
The invention includes a horizontally disposed rotating shaft to which is mounted one or more cylindrical housing. At least one strand of flexible filament is mounted to the housing(s) to radially extend therefrom. A motor is coupled to the shaft to cause rotation thereof, with the flexible filament. As such, the rotating shaft can be guided to lower the end of the spinning filament into a lawn to forcibly lift embedded thatch.
The filaments are preferably circumferentially staggered along the length of the housing(s) so that the filaments engage the thatch sequentially rather than in unison. The shaft can be driven either by an electrical motor or a gas-powered motor. With either source of motive force, it is preferred that wheels be mounted to the dethatcher to ease operation thereof. The use of flexible filament allows for a light, electrically-powered apparatus to be formed in accordance with this invention, which is ideal for home use. Additionally, the invention can also be used in conjunction with a heavy-duty, gas-powered model intended for professional gardeners and landscapers. It is preferred that each of the flexible filaments be securely held in the housing(s) by the clamping mechanism disclosed in U.S. Pat. No. 5,758,424, which issued on Jun. 2, 1998 and of which the inventor herein is a co-inventor. The disclosure of U.S. Pat. No. 5,758,424 is incorporated by reference herein.
REFERENCES:
patent: 5524425 (1996-06-01), Gallazzini
patent: 5577374 (1996-11-01), Huston
patent: 6158202 (2000-12-01), Jung
Casella Anthony J.
Hespos Gerald E.
Novosad Christopher J.
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