Preventive structure for preventing kudzu vines from getting entangled in brush cutters

Abstract

When using a brush cutter to remove weeds and other vegetation, this prevents the notoriously difficult-to-remove kudzu vines from becoming entangled in the rotating parts. [Solution] When using a nylon cord cutter, a small circular saw blade is attached in combination, and when using a metal blade, a saw-shaped three-blade attachment is attached. In both cases, the attachment of the present invention is attached to the side of the gear case to prevent entanglement. If the cord becomes firmly wrapped around the entire tip of the shaft, the tip of a sickle or knife can be inserted into the space or gap of the attachment to cut and remove it, immediately restoring rotation.

Description

Technical Field

[0001] The present invention relates to a prevention structure when kudzu vines wind around a rotating shaft in a weed cutter that attaches a nylon cord cutter or a chip saw to the rotating shaft at the tip of the shaft of the weed cutter and performs weed cutting operation by its rotation.

Background Art

[0002] For weed cutting, weed cutters that perform cutting operations with a nylon cord cutter or a chip saw rotating at high speed are generally used. However, kudzu vines that have been cut or are about to be cut strongly wind around the rotating shaft and become entangled, frequently resulting in a situation where rotation becomes impossible. To address such a situation, commercially available winding prevention cutters are sometimes used.

[0003] Incidentally, although commercially available winding prevention cutters have a certain effect, they only rotate in the same direction (counterclockwise when viewed from above) as the rotating nylon cord cutter or chip saw, and there are limitations in cutting the winding kudzu vines and the effect is considered to be weak. After all, it is considered that a cutter or blade body that rotates in the opposite direction (clockwise when viewed from above) to the nylon cord cutter or the like or at least remains stationary is required to have an effect.

Prior Art Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] While anti-tangle structures such as the cylindrical component disclosed in Patent Document 1, which prevents foreign matter from entering between the blade holder and the rotating nylon cord cutter or saw blade, and the sliding anti-tangle blade disclosed in Utility Model Document 2, which is mounted using bolt holes, may seem effective at first glance, there are doubts about whether they can truly eliminate tangles. Although many similar structures have been prototyped to date, they have not become widespread. Incidentally, regarding the use of bolt holes in Utility Model Document 2, the gear case itself is made of aluminum, so it may not withstand harsh work and the bolt holes may become crushed. Also, the sliding blade has many durability problems and is not suitable for practical use.

[0006] Given the principle of brush cutters, which cut weeds by rotating nylon cord cutters or saw blades, entanglement and wrapping are natural consequences, and empirically speaking, it is impossible to completely prevent foreign objects, including kudzu vines, from becoming entangled in the rotating shaft. While various commercially available anti-wrap cutters offer some degree of effectiveness as general weed control, none of them proved particularly effective against the formidable kudzu vine. The decisive reason why kudzu is considered impregnable is that it has thick, long vines that, ecologically, exist on the ground surface in a widespread, intricate, and multi-layered entanglement. Furthermore, its thin, strong fibers resist cutting and become entangled around the rotating shaft, making them difficult to remove.

[0007] In any case, the preventative structures and equipment that have been used in the past are heavy, bulky, complex, and costly, yet they seem to have little effect. Currently, when entanglement occurs, the engine must be stopped, the shoulder strap removed, the brush cutter lowered to the ground, and each vine or other vegetation removed one by one by hand, which is a time-consuming process.

[0008] When mowing grass using only a nylon cord cutter, kudzu vines can quickly entangle the cord, rendering it impossible to rotate. Some people try to reduce entanglement by attaching various types of saw blades between the blade holder and the nylon cord cutter, or by adding modified metal blades, but it is impossible to completely prevent this.

[0009] Furthermore, when using a three-blade metal saw blade designed to prevent entanglement as an alternative to a circular saw blade, while entanglement is indeed reduced compared to using only the circular saw blade, complete prevention is not possible. Depending on the engine's revving speed, and if the blade comes into contact with the ground, concrete, or metal workpieces, the rotational force decreases and entanglement can begin instantly. In the worst-case scenario, just like with nylon cord cutters, the kudzu vines can become intricately entangled, rendering the blade unable to rotate. [Means for solving the problem]

[0010] Kudzu vines begin to wrap around the skirt at the tip of the shaft, quickly entangling the entire shaft tip, including the nylon cord cutter and saw blade, eventually causing the rotation to stop and rendering the machine unusable. From experience, the biggest problem with any wrapping or entanglement is wrapping around the skirt, and if wrapping around the skirt is avoided, the machine will almost never stop rotating. Therefore, if a part is installed from the beginning to prevent grass from entering and wrapping around the skirt, or if grass does enter and wrap around, it can be quickly cut and removed, there will be no problem in the operation.

[0011] In view of the aforementioned drawbacks of conventional methods, the present invention aims to prevent the kudzu vines to be cut from directly wrapping around the rotating shaft with a simpler and lighter structure, and in the worst-case scenario where the vines become tightly wrapped and rotation becomes impossible, to immediately restore rotation on the spot without having to perform emergency engine shutdowns or recovery work after lowering the brush cutter.

[0012] The attachment according to the present invention is designed to prevent kudzu vines from entering the shaft gear case, specifically at the shaft tip skirt where they are most likely to wrap around the shaft, based on the empirical observation that kudzu vines inevitably become entangled during grass cutting. In the worst-case scenario, if kudzu vines become entangled and prevent rotation, the tip of a sickle or cutter blade can be inserted into the space or gap provided in the attachment to cut and completely remove the vines, immediately restoring the rotation function. [Effects of the Invention]

[0013] We have performed brush cutting in numerous work sites using combinations of nylon cord cutters, the smallest type of circular saw blade, and the attachment of the present invention, or combinations of a metal saw-shaped three-blade system and the attachment of the present invention. As a result, we have experienced the effectiveness of the attachment firsthand, and there have been no instances where we had to stop the engine or cut the vines with a sickle or utility knife, as anticipated in the worst-case scenario. This has reaffirmed its effectiveness as a structure to prevent kudzu vines from wrapping around the equipment. [Selection Diagrams] Figures 2 and 3 [Brief explanation of the drawing]

[0014] [Figure 1] Overall diagram of the attachment of the present invention [Figure 2] A diagram (perspective view) of the equipment configuration when using a nylon cord cutter to cut kudzu vines with a brush cutter, with a small saw blade and the attachment of the present invention attached. [Figure 3] A diagram (perspective view) of the equipment configuration when the attachment of the present invention is attached to a brush cutter using a metal saw-shaped three-blade system to cut kudzu vines. Mode for carrying out the present invention

[0015] The attachment of the present invention consists of a stainless steel U-shaped blade (6) and a stainless steel band (5). The U-shaped blade is attached to the gear case at the tip of the shaft using the band, on the left side as seen from the worker's perspective. The U-shaped blade has a sharp edge throughout due to polishing. When attaching, the band is wrapped around the gear case, but care is taken to avoid contact with the blade holder (9) that rotates directly below the gear case. The bottom part of the U-shaped blade is made as close as possible to the curved shaft tip gear case skirt (2) to prevent weeds from directly entering and wrapping around the skirt. Unlike nylon cord cutters or metal saw-shaped triple blades that rotate counterclockwise when viewed from above, the U-shaped blade is fixed in place and stationary, yet it effectively cuts and removes kudzu vines that wrap around them in a counterclockwise direction. While this prototype was made as a DIY project, for commercial use of this attachment, it would be desirable to use a U-shaped blade with the latest specialized technology for superior cutting performance.

[0016] The area around the gear case skirt at the shaft tip where the kudzu vines begin to wrap is a smooth surface, and if the kudzu vines become firmly wrapped around it, there is no space or gap to remove them, making the process quite time-consuming and difficult. To resolve this smoothly, we considered creating new space or gaps around the gear case. If the wrapping becomes particularly severe, inserting the blade of a sickle or cutter into the gaps around the space provided by the attachment will allow the kudzu vines to be completely removed and the rotation to be restored.

[0017] When actually using a brush cutter with a nylon cord cutter (4) attached, the order is to first attach the smallest type of saw blade (3) (which should be slightly larger than the nylon cord cutter), then the nylon cord cutter, to the blade holder at the tip of the rotating shaft and secure it with a special nut. If the smallest type of saw blade is not attached, the nylon cord cutter will draw in and wrap around the shaft tip or other parts of the kudzu vines that are not cut by its own rotation, causing them to quickly become entangled and stop rotating.

[0018] To summarize the structure for preventing kudzu vines from wrapping around the rotating shaft of a brush cutter, firstly, when using a nylon cord cutter, the smallest possible type of saw blade for weight reduction is added, and then the attachment of the present invention is attached. Secondly, when using a metal saw-shaped three-blade cutter, the same method is used as described above, with the attachment of the present invention attached. If kudzu vines become firmly wrapped around the entire tip of the shaft, rendering it unable to rotate, the tip of a sickle, knife, or other tool can be inserted into the space or gap of the attachment to cut and remove the vines, immediately restoring the rotation function. In normal mowing, it can be dealt with without problems by the first method. However, when kudzu vines are spreading extensively in large quantities in mountain forests, riverbanks, etc., it is judged that it is desirable to preferentially select the second method in terms of efficiency, fuel cost, etc. [Selected Drawing] Figure 2

Explanation of Reference Signs

[0019] 1 Shaft tip 2 Gear case skirt part 3 Small chip saw 4 Nylon cord cutter 5 Mounting band 6 U-shaped blade body 7 Space 8 Gap 9 Blade receiving fitting

Claims

1. When mowing grass with a brush cutter, a nylon cord cutter is generally used for soft and relatively short weeds. However, when encountering kudzu vines or long, easily entangled grasses (hereinafter referred to as "kudzu vines"), a small saw blade is attached in addition to the nylon cord cutter, and the attachment of the present invention is further attached and fixed to the side of the gear case at the tip of the shaft. This helps prevent kudzu vines from getting entangled, and in the event that kudzu vines cover the entire tip of the shaft and prevent rotation, the tip of a sickle or utility knife can be inserted into the space or gap of the attachment to cut the entangled kudzu vines, thus immediately and completely removing them. [Selection Diagrams] Figure 1, Figure 2

2. When mowing grass with a brush cutter, metal blades such as saw blades are generally used for tough and relatively long weeds. However, when encountering kudzu vines, the present invention's attachment is mounted on the shaft end gear case after attaching a three-blade metal saw-shaped attachment to help prevent kudzu vines from wrapping around the brush cutter. Furthermore, if kudzu vines completely cover the shaft end and prevent rotation, the tip of a sickle or utility knife can be inserted into the space or gap of the attachment to cut the vines, immediately and completely removing them. This is a brush cutter entanglement prevention structure. [Selection Diagrams] Figure 1, Figure 3

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