JPH11127654A - Rotary blade type mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small mower using two rotary blades capable of being rotated in the mutually opposite directions, capable of being easily introduced even on the footpath of a paddy field, small in work loads, and large in cutting forces. SOLUTION: This rotary blade type mower is provided with an obliquely extended frame having a hand-pushing handle attached thereto, wheels 4 placed on both the sides of the frame 1, and upper and lower rotary blades capable of being rotated on a vertical shaft pivotally supported on the tip of the frame 1. When the frame 1 is pushed with hands and moved, the rotations of the wheels 4 as a driving source permit to rotate the upper and lower rotary blades in the mutually opposite directions. The wheels 4 on both the sides of the frame are provided with one-way clutches for transmitting the forward rotations of the wheels 4 to a wheel shaft 7, and a planetary gear device for reversely rotating the vertical shaft is disposed at the lower end of the vertical shaft. The two rotary blades have the mutually different odd numbers of radially directed cutting blades, respectively. One kind of the cutting blades each has a projected shape at the central position in the rotation direction, and the other kind of the cutting blades each has a depressed shape at the central position in the rotation direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mower for cutting grass with two rotating blades rotating in opposite directions.

[0002]

2. Description of the Related Art Engine mowers are widely used as mowing machines using rotary blades. The engine bush cutter rotates one rotating blade at a high speed and cuts the grass with a sickle. On the other hand, a device provided with a comb-shaped fixed blade and a movable blade to cut grass so as to shear the grass with scissors is used in, for example, a lawn mower. Also, some lawn mowers shear the grass between a fixed blade and a rotary blade with a helical blade that rotates about a horizontal axis. Engine lawn mowers use a gasoline engine as the power source to drive the blades, but most lawn mowers that shear the grass with two blades are hand-operated, using the rotation of wheels that are rotated by manual movement as the drive source. The blade is reciprocating or rotating.

[0003]

The engine brush cutter uses a rotary blade. However, it is necessary to rotate the rotary blade at a high speed in order to cut grass, and it is a hand-held or shoulder-mounted type equipped with a gasoline engine. Therefore, care must be taken during handling and heavy labor is required.
Self-propelled or hand-operated mowers with wheels that are powered by rotating blades are also available, but the equipment is large and convenient for mowing large parks and riverbeds. For example, when mowing grass, the equipment is too large to be brought to the site. In addition, a device with an engine has a drawback that loud noise is generated during operation.

[0004] On the other hand, a lawn mower or the like that cuts grass by driving a blade by rotating a wheel by hand pushing can cut soft grass such as grass, but has a thick and strong stem like rice weed. It is difficult to mow weeds. Therefore, it is suitable for the maintenance of the lawn in the garden, but cannot cut the weeds that grew on the ridges of the rice fields.

[0005] The mowing work of the ridges in the field is usually performed using an engine brush cutter, but with the aging of the agricultural population, there is a demand for a device capable of weeding the ridges with a lighter work load. ing. Therefore, an object of the present invention is to provide a mower having a small size, which can be easily introduced into a ridgeway of a rice field, has a small work load, and has a large cutting force.

[0006]

According to a first aspect of the present invention, there is provided a rotary blade mower having a frame mounted with a push handle extending obliquely upward, and wheels mounted on both sides of the frame.
And an upper blade 25 and a lower blade 18 that rotate around a vertical axis that is pivotally supported at the end of the frame. The upper blade 25 and the lower blade 25 are driven by rotating the wheels 4 when the frame 1 is manually pushed. The blades 18 are rotated in opposite directions.

According to a second aspect of the present invention, in the rotary blade mower according to the first aspect, the wheels 4 located on both sides of the frame are freely rotatably mounted on the wheel shaft 7 mounted on the frame 1 so as to be freely rotatable. A one-way clutch 8 such as a ratchet for transmitting rotation of the wheel 4 in the forward direction to the wheel axle 7 is provided between each wheel and the wheel axle 7. And a planetary gear unit 15 for reversing the rotation of the vertical shaft at the lower end of the vertical shaft 12.

[0008] The invention described in claim 3 is claim 1 or 2.
In the rotary blade-type mower described, two rotary blades 25, 1
8 is an odd number of radial cutting blades 26, 27 having different numbers from each other.
Wherein one of the cutting blades 27 has a convex shape in the rotational direction, and the other cutting blade 26 has a concave shape in the rotational direction.

[0009]

The mowing machine according to the present invention, in which two rotating blades 18 and 25 rotating in opposite directions about a vertical axis are provided at the tip of a hand-pushed frame 1, a relatively large cutting blade is provided on the rotating blade. Since the grass is sandwiched from both sides by two cutting blades and cut by a shearing action, the cutting force is strong and the tough rice weed can be cut with a relatively light force. In particular, by employing the structure of the cutting blade according to the third aspect, a plurality of blades do not mesh with each other at the same time, so that a large cutting resistance is not generated on the rotary blade, and weeds guided between the upper and lower cutting blades can be cut. It is also possible to prevent escape from between the blades, and furthermore, since the curved cutting blade is cut diagonally into the weed stem, the weed stem can be cut with a lighter force.

[0010] Since weeds can be cut with a light force, even if the rotary blade is rotated by using a hand-operated wheel as a drive source, if the weeds grow on the levee, it is sufficient to cut the weeds. Driving force can be obtained. The wheels on both sides of the frame are freely rotatably mounted on the wheel axle that is freely rotatable on the frame, and a one-way clutch is provided between each wheel and the wheel axle to transmit the rotation of the wheel axle to the rotary blade The driving force based on the weight applied to the other wheel rotates the rotating blade, such as when one wheel floats during hand pushing movement, so the driving force of the rotating blade is large even when traveling on uneven terrain. It can be prevented from fluctuating.

The structure in which the planetary gears are used to rotate the upper blade and the lower blade in the reverse direction can drive the two rotary blades in opposite directions with a compact and simple structure.

[0012]

FIG. 1 and FIG. 3 show an embodiment of the present invention. A support shaft 2 is horizontally mounted on the frame 1 provided with the push handle 28, and wheels 4 having tires 3 on the outer periphery are mounted on both sides of the support shaft so as to be freely rotatable by needle bearings 5. ing. At a substantially center of the support shaft 2, a hollow wheel shaft 7 to which a bevel gear 6 is fixed.
Is provided on the support shaft 2 so as to be freely rotatable by a needle bearing. A ratchet 8 constituting a one-way clutch is provided between the inside of each wheel and the wheel shaft 7. The ratchet 8 transmits the rotation of each wheel 4 in the forward direction to the wheel shaft 7, and therefore transmits the rotational force of the faster rotating wheel to the wheel shaft 7 when the rotation speeds of both wheels are different. .
A bevel gear 9 meshing with the bevel gear 6 fixed to the wheel shaft 7 is fixed to an intermediate shaft 11 extending forward of the frame. The intermediate shaft 11 is rotatably mounted on the frame by bearings 5 at both ends.

A bearing bush 29 is mounted on the front end of the frame 1 in a vertical direction, and the vertical shaft 12 is rotatably mounted on the bearing bush 29 by needle bearings 5 and 5. A bevel gear 13 is fixed to the upper end of the vertical shaft 12 and meshes with a bevel gear 14 fixed to the front end of the intermediate shaft 11. A sun gear 16 of a planetary gear set 15 is fixed below the vertical shaft 12, and further below the lower blade bracket 17.
Are fixed, and the lower rotary blade 18 is fixed to the lower blade bracket 17.

The planetary gear 19 of the planetary gear device is rotatably supported by a shaft pin 21 erected on a bearing bush 29 so as to be freely rotatable. The planetary gear 19 is arranged at a position that divides the circumference into three equal parts. The outer peripheral gear 22 of the planetary gear device 15 is formed inside an upper blade holder 24 rotatably mounted on a bearing bush 29 with a bearing metal 23, and an upper rotary blade 25 is fixed to a lower end of the upper blade holder 24. Have been.

As shown in FIG. 4, the upper rotary blade 25 has seven cutting blades 26 extending in a direction that divides the circumference into seven equal parts in the radial direction. It is an arcuate cutting edge that is concave in the direction of rotation of the blade. The middle concave cutting blade 26 whose outer peripheral side is advanced in the rotation direction of the rotary blade prevents the grass introduced between the cutting blades from escaping to the outside of the rotary blade.

As shown in FIG. 5, the lower rotary blade 18 has five radially extending cutting blades 27 that divide the circumference into five equal parts, each of which is a rotary blade indicated by an arrow in the figure. The tip extends obliquely in the direction in which the tip retreats with respect to the rotation direction of the
Reference numeral 7 denotes a centrally convex arc cutting blade. The arcuate cutting edge with the retreated tip is obliquely abutted on the grass stalk introduced between the cutting edges to more effectively apply the shearing force.

In the mowing machine having the above structure, when the frame is advanced by pushing the push handle 28, the rotational force of the wheels 4 on both sides is transmitted to the vertical shaft 12 at the front end of the frame, and the two mowers provided at the lower end of the vertical shaft are provided. The rotating blades 18 and 25 are rotated in opposite directions. In the structure shown, the lower blade rotates faster and the upper blade rotates slower. The weed introduced between the cutting blades of the two rotary blades by the advance of the frame is sandwiched from both sides by the two cutting blades and cut by a shearing action. Since the cutting blades rotate together, the position where the cutting blades mesh changes, and the shearing action is imparted with a relatively large curved cutting blade.
A large cutting force is exhibited with a light force.

Further, even if one wheel is lifted by the action of a one-way clutch provided between the wheel and the wheel shaft, a driving force of a force corresponding to the increase in the supporting weight due to the lifting of one wheel from the other wheel. Is applied to the rotary blade, so that even when mowing while traveling on uneven terrain such as a ridge in a rice field, a stable driving force can be applied to the rotary blade.

Although the number of upper and lower rotary blades is set to 7 and 5 in the illustrated embodiment, other combinations such as 9 and 7 or 9 and 5 can be used. is there.

[0020]

According to the rotary blade mower of the present invention, weeds are sandwiched between both sides by two relatively large cutting blades rotating in opposite directions and cut by shearing action, so that the cutting force is strong and relatively light. It is possible to cut by force and to prevent the driving force of the rotary blade from fluctuating greatly even when traveling on uneven terrain.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing the entire mower.

FIG. 2 is a sectional plan view showing a main part of a wheel mounting portion.

FIG. 3 is a sectional side view of a main part showing a rotary blade mounting part.

FIG. 4 is a plan view of the upper blade.

FIG. 5 is a plan view of a lower blade.

[Explanation of symbols]

 1 Frame 2 Support shaft 4 Wheel 6 Bevel gear 7 Wheel shaft 8 Ratchet 9 Bevel gear 11 Intermediate shaft 12 Vertical shaft 18 Lower rotating blade 25 Upper rotating blade 26 Cutting blade 27 Cutting blade

Claims (3)

[Claims] 1. A frame (1) to which a push handle extending diagonally upward is mounted, wheels (4) located on both sides of the frame, and a frame that rotates about a vertical axis that is pivotally supported at the tip of the frame. The blade (25) and the lower blade (18) are provided, and the upper blade (25) and the lower blade (18) are moved in opposite directions by using the rotation of the wheel (4) when the frame (1) is manually pushed and moved as a driving source. A rotary blade-type mower characterized by being rotated. 2. The wheels (4) located on both sides of the frame,
Each wheel is rotatably mounted on a wheel shaft (7) mounted on the frame (1), and the forward rotation of the wheel (4) is applied to the wheel shaft (7) between each wheel and the wheel shaft (7). One-way clutch to transmit
(8) is provided, and rotation transmission means (6, 9, 11) for transmitting the rotation of the wheel shaft (7) to the vertical shaft (12) in front of the frame is provided, and at the lower end of the vertical shaft (12). 2. A rotary blade mower according to claim 1, further comprising a planetary gear unit for reversing the rotation of the vertical shaft. 3. The two rotating blades (25, 18) are provided with an odd number of radial cutting edges (26, 27) having different numbers from each other.
7) is characterized in that it is convex in the direction of rotation and the other cutting edge (26) is concave in the direction of rotation.
The described rotary blade mower.