JP2000236747A - Branch cutting tool and reciprocating type branch cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the power for pressing a branch against a saw blade and reduce the labor of an operator. SOLUTION: This tool 1 is capable of bending and deforming a branch 31 due to the action of a load W such as a branch cutting tool 1 on the branch 31 when a pawl 31 of a hook 16 is hooked on the branch 31, making the reactional force F of the branch 31 act on the hook 16, rotating the hook 16 with the rotation fulcrum 17 as the center and pressing the branch 31 against a saw blade 2. At this time, the rotation fulcrum 17 of the hook 16 is eccentric from the axial center C0 of an operating shaft 4 and the rotation angle of the hook 16 can be increased from that of a conventional example by the extent L of eccenstricity. Thereby, the branch 31 can be pressed against the saw blade 2 with a sufficient force and the branch 31 thicker by the extent L of the eccentricity can be cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch cutter used for cutting off a branch at a high place, and a reciprocating branch cutter having the branch cutter.

[0002]

2. Description of the Related Art Various types of branch cutting tools of this type have been proposed. For example, in a conventional branch cutting tool 1A shown in FIGS. 11 to 12, a saw blade 2 is fixed to the tip of a reciprocating operating shaft 4, and a hook 16 is attached to the saw blade 2 reciprocating with the operating shaft 4. The branch 31 is cut by pressing the branch 31 hooked in step (1).

The operating shaft 4 is reciprocated by an engine (not shown), and is slidably accommodated in a support cylinder 8 held by an operator's hand.
The hook 16 is rotatably attached to a rod guide 10A whose end is fixed to the tip of the support tube 8. When the hook 16 is hooked on the branch 31, the rotation fulcrum 17 is formed by the reaction force of the branch 31. Pivoted clockwise in FIG.
The branch 31 is pressed against the saw blade 2.

[0004]

However, such a conventional branch cutting tool 1A has a pivoting fulcrum 17 of the hook 16.
Is provided coaxially with the axis C0 of the operating shaft 4,
At the end of cutting the branch 31, the force of the hook 16 pressing the branch 31 against the saw blade 2 is almost negligible or extremely small. Therefore, the worker 34 must press the saw blade 2 against the branch 31 while holding the reciprocating branch cutting machine 33 provided with the branch cutting tool 1A, and furthermore, holds the posture of looking upward. In addition, the fatigue of the shoulders and arms in the pruning work was large (see FIG. 10).

[0005] Therefore, it has been desired to provide a branch cutting tool capable of further reducing the labor of the operator. It has also been desired to provide a reciprocating branch cutting machine provided with such an improved branch cutting tool. The present invention has been devised to meet such a demand.

[0006]

According to a first aspect of the present invention, there is provided an operation shaft housed in a support cylinder so as to be reciprocally movable, and fixed to a tip of the operation shaft, and reciprocated integrally with the operation shaft. A saw blade for cutting the branch, a rod guide fixed to the distal end of the support cylinder and guiding the reciprocating motion of the operating shaft, and rotatably attached to the rod guide to hook the branch. A branch cutting tool comprising: a hook provided with a claw; a spring member that constantly urges the hook claw to rotate away from the saw blade; and a stopper that regulates the amount of rotation of the hook. And the rotation fulcrum of the hook is arranged at a position eccentric with respect to the axis of the operating shaft. or,
The hook is attached to the rod guide such that the claw projects in a direction opposite to the eccentric direction of the rotation fulcrum with respect to the axis of the operating shaft and extends in a direction away from the saw blade. Further, the rotation of the hook is restricted by the stopper so that the claw does not protrude toward the rotation fulcrum with respect to the saw blade.

According to the present invention thus constructed, when the hook of the hook is hooked on the branch, a load such as a branch cutting tool acts on the branch, so that the branch is bent and deformed, and the reaction force of the branch is changed. Acts on the hook, and the hook pivots about the pivot point to press the branch against the saw blade. At this time, since the rotation fulcrum of the hook is eccentric from the axis of the operating shaft, the force for pressing the branch against the saw blade is larger than in the conventional example. Also, the present invention
Even at the end of cutting of the branch, the branch can be pressed against the saw blade with a sufficient force because the pivot point of rotation of the hook is at an eccentric position with respect to the axis of the operating shaft. Therefore, according to the present invention, the labor of the worker is remarkably reduced as compared with the conventional example. Further, in the present invention, since the rotation fulcrum of the hook is eccentric with respect to the axis of the operating shaft having the saw blade, the hook is extra than the conventional example by the amount of eccentricity of the rotation fulcrum. Rotate.
Therefore, according to the present invention, it is possible to easily cut a thick branch that could not be cut in the conventional example.
Further, in the present invention, the amount of rotation of the hook is regulated by the stopper so that the hook claw does not protrude toward the rotation fulcrum with respect to the saw blade. And no malfunction of the saw blade is caused.

A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the nail has a plurality of teeth formed on the outer surface of the branch.

With this configuration, the branches can be reliably caught by the claws, so that the cutting position of the saw blade is stable, and the cutting operation can be performed efficiently.

A third aspect of the present invention is characterized in that, in the first or second aspect of the present invention, the hook has a substantially arc-shaped claw that curves from the vicinity of the rotation fulcrum.

According to the present invention having such a configuration, it is possible to reliably hook a branch having a complicated shape or a thick branch.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the hooks are arranged on both side surfaces of the saw blade.

According to the present invention having such a configuration, the branch portion between the supports supported by the hooks on both sides is cut by the saw blade. A branch cutting operation is performed. Further, according to the present invention, since the branch is pressed against the saw blade by the hooks on both sides, the force for pressing the branch against the saw blade is large, and the branch cutting operation can be performed easily and reliably.

According to a fifth aspect of the present invention, in the first or fourth aspect, the hook is detachably attached to the rod guide.

According to the present invention having such a configuration, in the case where the branches are densely grown and the hooks are difficult to be hooked on the branches, one of the two hooks is removed and the branch cutting operation is performed. It becomes possible.

According to a sixth aspect of the present invention, there is provided an operating shaft housed reciprocally in a support cylinder, and fixed to a tip of the operating shaft,
A saw blade for reciprocating with the operating shaft to cut a branch, a hook rotatably attached to the distal end side of the support cylinder and having a claw capable of hooking the branch, and a claw of the hook are provided. A branch cutting tool including a spring member that constantly rotates and biases in a direction away from the saw blade, and a stopper that regulates a rotation amount of the hook. And the rotation fulcrum of the hook is
It is arranged at a position eccentric to the axis of the operating shaft. The hook is attached to the distal end side of the support tube so that the claw projects in a direction opposite to the eccentric direction of the rotation fulcrum with respect to the axis of the operating shaft and extends in a direction away from the saw blade. Have been. The hook is restricted by the stopper so that the claw does not protrude toward the rotation fulcrum with respect to the saw blade. Here, the hook may be rotatably attached to a hook support formed directly on the support cylinder, or may be rotatably attached to a hook support fixed to the support cylinder. It should be noted that the hook supporting portion is not limited to the rod guide and the like as long as it can rotatably support the hook.

According to a seventh aspect of the present invention, there is provided an operating shaft housed in a support cylinder so as to be reciprocally movable, a power transmitting means connected to the operating shaft for converting a rotary motion into a linear motion, and a power transmitting device. A driving means connected to the operating shaft through the operating shaft to reciprocate the operating shaft, a saw blade fixed to the tip of the operating shaft and reciprocating integrally with the operating shaft to cut a branch, A rod guide fixed to the distal end and guiding the reciprocating movement of the operating shaft, a hook rotatably attached to the rod guide and having a hook capable of catching a branch, and a hook of the hook are provided. The reciprocating branch cutting machine includes a spring member which constantly rotates and biases in a direction away from the saw blade, and a stopper which regulates a rotation amount of the hook. And the rotation fulcrum of the hook is arranged at a position eccentric with respect to the axis of the operating shaft. The hook is attached to the rod guide such that the claw projects in a direction opposite to the eccentric direction of the rotation fulcrum with respect to the axis of the operating shaft and extends in a direction away from the saw blade.
Further, the rotation of the hook is restricted by the stopper so that the claw does not protrude toward the rotation fulcrum with respect to the saw blade.

According to an eighth aspect of the present invention, in the above-mentioned seventh aspect, the hooks are arranged on both side surfaces of the saw blade.

According to the present invention having such a configuration, even if the worker is located on either the left or right side of the tree, one of the two hooks is always hooked on the branch side left uncut. Therefore, even after the branch cutting operation is completed, the weight of the reciprocating branch cutting machine does not suddenly act on the operator, and the branch cutting operation is smoothly performed from the start to the end.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIGS. 1 to 4 show a branch cutting tool 1 according to a first embodiment of the present invention. 1 is a front view of the branch cutting tool 1. FIG.
FIG. 2 is a side view of the branch cutting tool 1 (a right side view of FIG. 1).
It is. FIG. 3 is a rear view of the branch cutter 1. FIG. 4 is an external perspective view of the branch cutting tool 1.

As shown in these figures, the saw blade 2 has a lower end 3 attached to a mounting plate 5 at an end (upper end) of an operating shaft 4 by screws 6.
, And reciprocate integrally with the operating shaft 4. The saw blade 2 has a plurality of substantially triangular teeth 7 formed on both sides, and its external dimensions are determined in consideration of the stroke of the operating shaft 4, the thickness of the branches, and the like. Here, the saw blade 2 can be used upside down by removing the screw 6.

As shown in FIG. 6, the operating shaft 4 is supported so that its tip 4a can slide on a rod guide 10 fixed to the upper end of the support cylinder 8. And
The operating shaft 4 has a notch 11 formed therein.
A detent piece 12 engages with the notch 11. Here, the rotation preventing piece 12 is a screw 13
Is fixed to the support cylinder 8 together with the rod guide 10 by
The rotation of the operating shaft 4 is stopped, and the operating shaft 4 is
Also, the rod guide 10 is prevented from falling out. The lower end of the operating shaft 4 is connected to an engine (drive means) 15 via a power transmission means 14 for converting a rotary motion into a linear reciprocating motion (see FIG. 10).

The portion of the rod guide 10 exposed to the outside from the support tube 8 is formed in a substantially rectangular parallelepiped shape, and the portion exposed to the outside from the support tube 8 is a hook support portion for rotatably supporting the hook 16. Functions as 10a. One end portion (lower end portion) of the hook 16 is rotatably and detachably attached to the hook support portion 10 a of the rod guide 10 by a bolt 17. This hook 1
The rotation fulcrum 6, that is, the bolt 17 that rotatably supports the hook 16, is disposed at a position deviated by a predetermined dimension (L) from the axis of the operating shaft 4.

A stopper 18 for restricting the amount of rotation of the hook 16 is fixed to the upper surface 10b of the rod guide 10 with a screw 20. As shown in FIG. 5, the stopper 18 is formed with a rectangular notch 21 that engages with the hook 16.
2, 23 abut on the side surface of the hook to regulate the rotation of the hook. Reference numeral 24 denotes a hole into which the shaft of the screw 20 is inserted.

The end of the stopper 18 has a spring stopper hole 2 for engaging one end 25a of a spring (spring member) 25.
6 are formed. This spring stopper hole 26 has one end 25a.
The other end 25b of the spring 25 with which the
Stopper hole 28 of spring support 27 formed at the lower end of
And urges the hook 16 to rotate so that the tip end (upper side) of the hook 16 protrudes in the direction opposite to the eccentric direction of the rotation fulcrum (bolt) 17 of the hook 16.

The hook 16 has a curved claw 30 formed at the tip thereof, and the hook 30 hooks the branch 31 (see FIG. 10). And hook 1
6 is supported by the rod guide 10 so that the claw 30 extends in a direction away from the saw blade 2. Also, hook 16
Since it is necessary to securely hold the branch 31 at a portion near the teeth 7 of the saw blade 2, an intermediate portion is bent so that a portion aligned with the saw blade 2 is located near the saw blade 2. . Here, a plurality of teeth 32 that are caught on the outer surface of the branch 31 are formed on the inner peripheral surface side of the curved claw 30. Therefore, the branch 31 is securely held by the teeth 32 of the claw 30, and the cutting position of the branch 31 by the saw blade 2 is stabilized, so that the cutting operation of the branch 31 is performed smoothly.

Here, the hook 16 is, as described above,
The rotation of the claw 30 is restricted by the stopper 18 fixed to the rod guide 10 so that the tip of the claw 30 does not protrude (disengage) on the right side (the rotation fulcrum 17 side) with respect to the saw blade 2 in the drawing. . Therefore, according to the branch cutter 1 of the present embodiment, as shown in FIG. 13, the tip of the claw 30 protruding to the right side of the saw blade 2 enters the back side of the saw blade 2 for some reason, and the saw blade 2 The claw 30 of the hook 16 is intertwined and the saw blade 2
Therefore, it is possible to perform a smooth branching operation without causing a problem such as an operation failure.

The operating shaft 4 of the branch cutting tool 1 configured as described above is connected to an engine (drive means) 15 via a power transmission means 14 for converting a rotary motion into a linear reciprocating motion. The reciprocating branch cutting machine 33 is constituted by the branch cutting tool 1, the power transmission means 14, and the engine 15.

The branch cutting tool 1 thus configured is shown in FIG.
As shown in FIG. 7 and FIG.
The branch 31 is subjected to a load W (eg, the weight of the engine 15 or the force with which the operator 34 pulls the support cylinder 8) on the branch 31, so that the branch 31 bends and deforms, and the reaction force F of the branch 31 causes a hook. Acts on 16. The rotation direction component Fra of the reaction force F
Is given by Fra = W × L1 / L2 from the balance of the moment about the pivot 16 of the hook 16. And
The hook 16 presses the branch 31 against the saw blade 2 with the rotation direction component Fra of the reaction force F. Force Fr for pressing this branch 31 against the saw blade
a is a force Frb (Frb = W × L0 / L2) for pressing the branch 31 of the conventional example against the saw blade 2 because the rotation fulcrum 17 of the hook 16 is eccentric by the dimension L from the axis of the operating shaft 14. However, it is larger than L0 = L1-L) (see FIG. 11).

The saw blade 2 reciprocates integrally with the operating shaft 4 reciprocated by the engine 15,
Cuts the branch 31 pressed by. At this time, the branch 31 is prevented from running upward in the sawing direction by the hook 16 and is pressed against the saw blade 2. As the cutting operation of the branch 31 proceeds, the hook 16 presses the branch 31 against the saw blade 2,
It turns clockwise in FIG. 7 around the turning fulcrum 17. Then, as shown in FIG.
Even at the end of cutting, the rotation fulcrum 17 is at an eccentric position with respect to the axis of the operating shaft 4, so that the branch 3
1 can be pressed against the saw blade 2. Therefore, at the end of cutting the branch 31, the operator 34 removes the saw blade 2 from the branch 31.
To the operator 34 compared to the conventional example.
Is significantly reduced (see FIG. 10).

Here, since the rotation fulcrum 17 of the hook 16 is eccentric to the axis C0 of the operating shaft 4 by the dimension L, the hook 16 is parallel to the axis C0 of the operation shaft 4 through the rotation fulcrum 17. Rotate until the contact point P with the branch 31 moves on the eccentric axis C1 of. Comparing this point with the conventional example, the hook 16 of the conventional example stops rotating when it moves over the axis C0 of the operating shaft 4, as shown in FIG. That is, the branch cutting tool 1 of the present embodiment can cut a branch that is thicker by the eccentric dimension L than the conventional example.

It should be noted that a comparison between a case where a novice performs a branch cutting operation using the branch cutting tool 1 according to the present embodiment and a case where a beginner performs a branch cutting operation using the conventional cutting tool 1A is shown. While the branch cutting tool 1 of the present embodiment can cut a branch having a thickness of 7 cm in less than 10 seconds, the conventional branch cutting tool 1A can cut a branch having a thickness of 3 cm in 30 seconds. It took some time.

As described above, according to the present embodiment, since the rotation fulcrum 17 of the hook 16 is eccentric with respect to the axis C0 of the operating shaft 4, the cutting of the branch 31 is started from the start of cutting the branch 31. Until the end, the branch 31 can be pressed against the saw blade 2 with a sufficient force, the labor of the operator 34 is remarkably reduced, and the efficiency of the pruning operation is remarkably improved. Moreover, it is possible to easily cut even the thick branches 31 that could not be cut conventionally. In addition, even a beginner can easily perform a branch cutting operation by using the branch cutting tool 1 of the present embodiment.

In this embodiment, the hook 30 of the hook 16 is
1, the shape of the arc is formed as shown in FIG. 1. However, the shape is not limited to this. Any shape that can hook the branch 31 may be used. For example, the shape of the claw 30 may be formed in a polygonal shape. Is also good. Further, as shown in FIG. 9, if the hook 30 of the hook 16 is formed into a large curved shape from the vicinity of the rotation fulcrum 17, the branch 31 or the thick branch 31 having a complicated shape can be easily hooked. become.

In the present embodiment, as shown in FIG. 10, a mode is shown in which the branch 31 is cut with a plurality of support cylinders 8 having a predetermined length and a plurality of operating shafts 4 connected to each other. Consideration is given so that the length of the support cylinder 8 and the operating shaft 4 can be adjusted according to the environment.

Further, in the above embodiment, the hook 1
The amount of eccentricity L of the rotation fulcrum 17, the size of the claw 30 of the hook 16, the amount of rotation of the hook 16, etc.
The branch 31 can be efficiently cut by being appropriately determined according to the thickness of the branch 31 or the like.

In addition, in the above embodiment, the saw blade 2
Although the teeth 7 have a substantially triangular shape as an example, the present invention is not limited to this, and the teeth 7 may be formed in any shape that is convenient for cutting the branches 31.

[Second Embodiment] FIGS. 14 and 15 show
9 shows a second embodiment of the present invention. As shown in these drawings, the branch cutting tool 1 of the present embodiment has a saw blade 2
A pair of hooks 16 (16A, 16B) are rotatably mounted so as to have a substantially symmetrical shape with respect to. Since the basic configuration is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted.

As described above, if the hooks 16A and 16B are attached to both sides of the saw blade 2,
Even if the worker 34 is located on either the left or right side with respect to 1A, one of the hooks 16A and 16B is hooked on the uncut branch 31 on the trunk side. Therefore, branch 3
1 is cut off by the saw blade 2, the branch cutter 1 and the reciprocating branch cutter 33 equipped with the branch cutter 1.
Is caught on the branch 31 left uncut, and the worker 34
The load of the branch cutting tool 1 and the reciprocating branch cutting machine 33 provided with the branch cutting tool 1 does not suddenly act on the branch 3.
1 can be smoothly finished (see FIG. 10).
reference). Further, as described above, even if the worker 34 is located on either side of the tree 31A, the cutting operation of the branch 31 can be finished smoothly. Is less restricted by the position of

As described above, according to the present embodiment, the hooks 16A, 16B are provided on both side surfaces of the saw blade 2, respectively.
Is attached, the central portion of the branch 31 held by both hooks 16A and 16B is cut by the saw blade 2, and the branch 31 is hard to escape due to cutting resistance.
1, the branch 31 can be cut in a stable state, and the branch 31 can be cut cleanly. Therefore, according to the present embodiment, it is possible to perform better care of the tree 31A than in the first embodiment.

As described above, according to the present embodiment, the hooks 16A, 16B are provided on both side surfaces of the saw blade 2, respectively.
Is attached, the force for pressing the branch 31 against the saw blade 2 is increased, so that the branch 31 can be cut more smoothly and more easily than in the first embodiment. In this embodiment, one of the hooks 16A and 16B is caught on the uncut branch 31. Therefore, the branch 31 is securely pressed against the saw blade 2 until the cutting operation of the branch 31 is completed. be able to.

Here, the branch cutting tool 1 according to the present embodiment.
Is designed so that the hooks 16A and 16B are detachably attached to the rod guide 10. Therefore, when one of the pair of hooks 16A and 16B interferes with the cutting of the branch 31, one of the hooks Remove the branch 3
1 can be cut. In this case, by leaving a hook to be hooked on the branch 31 to be cut off and removing the hook on the side of the branch 31 to be cut off, the branch 31 is applied to the saw blade 2 with the same force from the start to the end of the cutting operation of the branch 31. The branch 31 can be pressed, and the branch 31 can be cut smoothly and reliably.

FIG. 10 exemplifies a use state of the branch cutting tool 1 and the reciprocating branch cutting machine 33 provided with the branch cutting tool 1, and the branch cutting tool 1 of each of the above-described embodiments and the branch. FIG. 1 shows a state of use of the reciprocating cutter 33 having the cutting tool 1.
It is not limited to zero. That is, in each of the above embodiments, the branch 3 from which the hook 16 of the branch cutting tool 1 is left uncut.
If the branch 31 is cut so as to be hooked to one side, the branch 31 can be cut smoothly and reliably from the start to the end.

[0045]

As described above, according to the present invention, since the rotation fulcrum of the hook is located at a position eccentric from the axis of the operating shaft provided with the saw blade, from the start of cutting the branch to the end of cutting the branch. The branch can be pressed against the saw blade by the hook, and the force for pressing the branch against the saw blade is increased as compared with the conventional example, so that the labor of the operator is reduced and the efficiency of the branch cutting operation is improved. .

Also, in the present invention, since the rotation fulcrum of the hook is located at a position eccentric from the axis of the operating shaft provided with the saw blade, the hook can be rotated more by the amount of eccentricity of the rotation fulcrum than in the conventional example. Move. Therefore, according to the present invention, a branch thicker than the conventional example can be easily cut.

Further, in the present invention, the rotation of the hook is regulated by the stopper so that the hook of the hook does not protrude toward the rotation fulcrum with respect to the saw blade. It is possible to prevent a malfunction of the saw blade caused by entering the side.

Further, according to the present invention, hooks are attached to both side surfaces of the saw blade, respectively, so that the branches are securely supported by both hooks, and the hook is attached to one side of the saw blade. Since the branch can be pressed against the saw blade with a large force, the branch can be more easily and reliably cut.

Further, as described above, according to the present invention, hooks are attached to both side surfaces of the saw blade, and the branch between the hooks is cut by the saw blade. , The saw blade can be applied to the branch at a substantially right angle, and the branch can be cut more clearly.

In addition, according to the present invention, as described above, since the hooks are attached to both side surfaces of the saw blade, one of the hooks is always hooked on the branch side where one of the hooks is left uncut. That is, the load of the branch cutting tool and the reciprocating branch cutting machine provided with the branch cutting tool after the branch cutting does not suddenly act on the operator. Moreover, according to the present invention, since the hook hooked on the side of the branch to be cut can press the branch against the saw blade with almost the same force from the start to the end of cutting the branch, the cutting operation of the branch is completed from the start. This is done smoothly and reliably.

[Brief description of the drawings]

FIG. 1 is a front view of a branch cutting tool according to an embodiment of the present invention.

FIG. 2 is a side view (right side view of FIG. 1) of the branch cutting tool.

FIG. 3 is a rear view of the branch cutting tool.

FIG. 4 is an external perspective view of the branch cutting tool.

FIG. 5 is a plan view of a stopper.

FIG. 6 is a cross-sectional view of an operation shaft support portion.

FIG. 7 is a first operation state diagram of the branch cutter.

FIG. 8 is a second operation state diagram of the branch cutter.

FIG. 9 is a front view of a branch cutting tool according to another embodiment of the present invention.

FIG. 10 is a diagram illustrating a use state of a reciprocating branch cutting machine provided with the branch cutting tool of the present invention.

FIG. 11 is a front view of a conventional branch cutting tool.

FIG. 12 is an operation state diagram of a conventional branch cutting tool.

FIG. 13 is a view showing a state in which a defect occurs in the branch cutting tool.

FIG. 14 is a perspective view of a branch cutting tool according to a second embodiment of the present invention.

FIG. 15 is a side view of the branch cutting tool.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Branch cutting tool, 2 ... Saw blade, 4 ... Operating shaft, 8 ... Support cylinder, 10 ... Rod guide, 14 ... Power transmission means,
15. Engine (drive means), 16, 16A, 16B
... Hook, 17 bolt (rotation fulcrum), 18 stopper, 25 spring (spring member), 30 claw, 31
... branches, 32 ... teeth, C0 ... axis

Claims (8)

[Claims] An operating shaft housed reciprocally in a supporting cylinder; a saw blade fixed to a tip of the operating shaft and reciprocating with the operating shaft to cut a branch; A rod guide fixed to the distal end of the rod and guiding the reciprocating motion of the operating shaft; a hook rotatably attached to the rod guide and having a claw capable of hooking a branch; and a claw of the hook. And a stopper for regulating the amount of rotation of the hook. A branch cutting tool comprising: So that the claw protrudes in the direction opposite to the eccentric direction of the rotation fulcrum with respect to the axis of the operating shaft and extends in a direction away from the saw blade. The hook is attached to the rod guide Both branches cutting tool wherein the pawl is so does not project to the pivot point side with respect to the saw blade, said hook, characterized in that it is the rotation restriction by the stopper. 2. The branch cutting tool according to claim 1, wherein the nail has a plurality of teeth formed on the outer surface of the branch. 3. The branch cutting tool according to claim 1, wherein the hook has a substantially arc-shaped claw that curves from the vicinity of the rotation fulcrum. 4. The branch cutting tool according to claim 1, wherein the hooks are arranged on both sides of the saw blade. 5. The branch cutting tool according to claim 1, wherein the hook is detachably attached to the rod guide. 6. An operating shaft housed reciprocally in a supporting cylinder, a saw blade fixed to a tip of the operating shaft, and reciprocating integrally with the operating shaft to cut a branch; A hook that is rotatably attached to the tip end of the hook and has a claw that can hook a branch; a spring member that constantly rotates and biases the hook of the hook in a direction away from the saw blade; A stopper that regulates the amount of movement; and a branch cutting tool comprising: a pivotal fulcrum of the hook disposed at a position eccentric to an axis of the operating shaft; The hook is attached to the distal end side of the support cylinder so that the hook protrudes in the direction opposite to the eccentric direction of the rotation fulcrum with respect to the core and extends away from the saw blade, and the claw is attached to the saw blade. So that it does not protrude toward the pivot point. Branch cutting tool, characterized in that the click is rotated restricted by the stopper. 7. An operating shaft housed reciprocally in a support cylinder, power transmitting means connected to the operating shaft and converting rotational motion into linear motion, and the operating shaft via the power transmitting means. A driving means for reciprocating the operating shaft, a saw blade fixed to the distal end of the operating shaft, and reciprocating integrally with the operating shaft to cut a branch; A rod guide that is fixed and guides the reciprocating motion of the operating shaft; a hook that is rotatably attached to the rod guide and has a claw that can hook a branch; and releases the claw of the hook from the saw blade. A reciprocating branch cutting machine comprising: a spring member that constantly rotates and biases the hook in a direction; and a stopper that regulates the amount of rotation of the hook. The claw is disposed at an eccentric position with respect to the The hook is attached to the rod guide so that the hook protrudes in a direction opposite to the eccentric direction of the rotation fulcrum with respect to the axis of the operating shaft and extends in a direction away from the saw blade. A reciprocating branch cutting machine, wherein the hook is restricted in rotation by the stopper so as not to protrude toward the rotation fulcrum with respect to a blade. 8. The reciprocating branch cutting machine according to claim 7, wherein the hooks are arranged on both sides of the saw blade.