Rotary blade for mower

Abstract

To solve a problem that, in a rotary-type mower, a cutting blade contacts a stone, block, or the like, and the cutting blade is damaged or a tip is detached in many cases, which reduces sharpness and durability.SOLUTION: A rotary blade for mower is attached to a rotary shaft part and rotates for mowing grass. The rotary blade for mower has one or more of the following features: cutting blades are provided in both ends of a plurality of projection parts provided on a circumference with an interval from each other; the projection parts including the cutting blades are installed so as to be inclined to upward and downward alternately; and a distal end portion of each of the plurality of projection parts provided on the circumference with an interval from each other is located in the outside from a cutting blade distal end portion having the longest distance from a circular center.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rotary blade for a grass cutter, and more particularly to a rotary blade for a grass cutter that protects the cutting blade from stones, blocks, etc., making it harder for the blade to lose its sharpness and lasting longer. [Background technology]

[0002] The cutting blades of rotary blades for lawn mowers are made of hard, durable materials like chip saw blades, and the shape of the cutting blades is designed to maintain their sharpness for a long time. Summary of the Invention [Problem to be solved by the invention]

[0003] Although various measures have been taken as mentioned above, it is common for the cutting blade to come into contact with stones or blocks, damaging the cutting blade and causing chips to come off. No matter how careful you are, the cutting blade will be damaged and lose its sharpness. The challenge is to reduce contact of stones, blocks, etc. with the cutting blade while maintaining sharpness and improving durability. [Means for solving the problem]

[0004] Therefore, the present inventors have devised the following means. 1. A rotary blade for a grass cutter, which is attached to a rotating shaft and rotated to cut grass, characterized in that it has cutting blades on both ends of multiple protruding portions spaced apart around the circumference. 2. A rotary blade for a lawnmower that cuts grass by being attached to a rotating shaft and rotated, characterized in that the protruding portions having cutting blades are tilted alternately up and down. 3. A rotary blade for a grass cutter, which is used in a grass cutter that cuts grass by being attached to a rotating shaft and rotated, characterized in that the tip of each of the multiple protrusions spaced apart on the circumference is located outside the tip of the cutting blade that is farthest from the center of the circle. It has been found that the problem can be solved by using one or a combination of two or more of these means.

[0005] This will be explained in more detail. First, the terminology will be explained. The rotary blade for a grass trimmer refers to the entire disk-shaped part made of metal or other material attached to the rotating shaft of the grass trimmer. The cutting blade is the part that cuts the grass, and there are multiple cutting blades on the rotary blade for a grass trimmer (usually 40 to 60), and it affects the sharpness and durability. Recently, there are many models that have tips attached that are different from the material of the rotary blade for a grass trimmer. Next, the following will be explained. This article explains "1. A rotary blade for a grass cutter, which is used for a grass cutter that cuts grass by being attached to a rotating shaft and rotated, characterized in that it has cutting blades on both ends of multiple protruding portions spaced apart around the circumference." Until now, the cutting blades of rotary blades for lawn mowers have only been attached in a direction that allows cutting when rotated in one direction.

[0006] next, "2. A rotary blade for a grass cutter for a grass cutter that is attached to a rotating shaft and rotated to cut grass, characterized in that the protruding parts having cutting blades are tilted up and down alternately." In the case of saws used to cut wood, etc., this refers to the attachment of protrusions that are tilted alternately left and right so that they protrude beyond the thickness of the rotary blade, a technique known as "asari (tooth vibration)." This serves the purpose of reducing friction with the saw blade when cutting wood, making the pushing and pulling motion easier and discharging sawdust. However, when cutting grass, an "asari (tooth vibration)" is not necessary for this purpose. In addition, "the protruding parts with cutting blades are alternately top and bottom The reason why we say "tilted" and "up and down" is that when used perpendicular to the object being cut, like a saw, it means "left and right". In the case of a lawnmower, it is used horizontally to the ground, so it means "up and down" relative to the ground. However, it has been found that when the rotary blade is rotated at high speed to cut grass, if the protruding parts with the cutting blades are not tilted up and down alternately, the proportion of the cutting blades that come into contact with the grass being cut can be prevented from decreasing. Although this varies greatly depending on the size of the protrusions and the rotation speed, the angle is preferably 2 to 45 degrees relative to the rotary blade, and more preferably 5 to 20 degrees. If it is less than 2 degrees, the effect is weak, and if it is more than 45 degrees, the resistance due to rotation becomes too great.

[0007] Next, we will explain "3. A rotary blade for a grass cutter for a grass cutter that is attached to a rotating shaft and rotated to cut grass, characterized in that the tip of each of the multiple protrusions that are present at intervals on the circumference is located outside the tip of the cutting blade that is farthest from the center of the circle." The biggest problem with grass cutters is that the cutting blades come into contact with hard objects such as stones or blocks, damaging the blades and making them less sharp. In the case of chipped saw blades, chipping can also occur. It was found that the problem could be solved by making the tip of each of the multiple protrusions spaced around the circumference more outside than the tip of the cutting blade that is farthest from the center of the circle. It was found that when using a rotary blade for a lawnmower, the first part to come into contact with stones, blocks, etc. is the "tip of the protruding part that is located outside the tip of the cutting blade that is the farthest from the center of the circle," preventing damage to the cutting blade. The difference in distance from the center of the circle between the "tip of the cutting blade farthest from the center of the circle" and the "tip of the protruding part located further out" varies depending on the type and hardness of the grass, but is preferably 0.5 mm to 5.0 mm, and most preferably 1.0 mm to 3.0 mm. If it is less than 0.5 mm, it will not be effective in protecting the cutting blade, and if it is more than 5.0 mm, the rate at which the cutting blade comes into contact with the grass being cut will decrease, reducing the efficiency of grass cutting. There are no particular restrictions on the shape of the protrusion between the two cutting blades installed on both ends of the protrusion, but a circular arc or triangular shape is preferred to reduce the impact when hit by a stone or the like.

[0008] moreover "3. A rotary blade for a grass cutter for a grass cutter that is attached to a rotating shaft and rotated to cut grass, characterized in that the tip of each of the multiple protrusions that are spaced apart on the circumference is located outside the tip of the cutting blade that is farthest from the center of the circle." 2. By "installing the protruding parts with cutting blades tilted up and down alternately," the proportion of the cutting blades that come into contact with the grass being cut increases, making it possible to cut grass more efficiently. [Effects of the Invention]

[0009] As described above, by using one or a combination of two or more of the following three means, a rotary blade for a grass cutter that maintains its sharpness for a long time has been obtained. I found that it solved the problem. 1. A rotary blade for a grass cutter, which is attached to a rotating shaft and rotated to cut grass, characterized in that it has cutting blades on both ends of multiple protruding portions spaced apart around the circumference. This makes it economical to use the three blades on both ends by flipping the blade over and attaching it to the rotating shaft of the grass cutter when the blade has lost its sharpness after a certain amount of use. The usable time has doubled. 2. A rotary blade for a lawnmower that cuts grass by being attached to a rotating shaft and rotated, characterized in that the protruding portions having cutting blades are tilted alternately up and down. This allows the cutting blade to more easily hit the grass, resulting in more efficient mowing. 3. A rotary blade for a grass cutter, which is used in a grass cutter that cuts grass by being attached to a rotating shaft and rotated, characterized in that the tip of each of the multiple protrusions spaced apart on the circumference is located outside the tip of the cutting blade that is farthest from the center of the circle. This reduces the contact of the cutting blade with stones or blocks, allowing it to remain sharp for a long time. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing a part of a rotary blade for a grass cutter. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] 2 is a cross-sectional view of FIG. 1 taken along line B-B. [Figure 4] 2 is a view similar to FIG. 1 showing a part of a rotary blade for a grass cutter. [Explanation of symbols]

[0011] 1. Rotary blade for grass cutter 2. Protruding part 21.Tip of protruding part 3.Cutting blade 31. Cutting blade tip 4.Circumference of the cutting blade tip 5.Circumference of the tip of the protruding part 6. Bending line of the protruding part of the rotary blade for the grass cutter

Claims

1. This is a rotary blade for a grass cutter that is attached to a rotary shaft and rotated to cut grass, and is characterized in that it has cutting blades on both ends of a plurality of protruding portions that are spaced apart on the circumference.

2. This is a rotary blade for a grass cutter that is attached to a rotary shaft and rotated to cut grass, characterized in that protruding parts having cutting blades are alternately tilted up and down.

3. This rotary blade for a grass cutter is for a grass cutter that cuts grass by being attached to a rotary shaft and rotated, and is characterized in that the tip of each of the plurality of protrusions present at intervals on the circumference is located outside the tip of the cutting blade that is farthest from the center of the circle.

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