JPH05137440A - Cutter-holding structure in mower - Google Patents

Abstract

PURPOSE:To provide the subject safe structure capable of attaching/detaching a cutter without necessitating any tool, equipped with a holder for the cutter, a hollow driving shaft penetrating through a shaft fixed to the holder, a supporting tool for one end of the shaft, and a fixing part for the supporting tool. CONSTITUTION:The objective structure equipped with a holder 2 for a cutter 1, a hollow driving shaft 4 penetrating through a shaft 3 fixed to this holder 2, a supporting part 5 for one end of this shaft 3, and a fixing part 6 for this supporting part 5. The supporting part 5 is made up of a rigid ball 7 engaged with a recess groove 3a provided on one end of the shaft 3 and a housing holding this ball 7, while the fixing part 6 is made up of an annular slider 9 pushing the ball 7 to the recess groove 3a side, an operating lever 10 for this slider 9 and a stopper 11 for this lever 10. Thereby, the objective structure can be obtained so as to enable the cutter to be attached/detached without necessitating any tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade holding structure for a mower.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional blade holding structure for a mower has a holder A41 and a holder B4 with respect to a drive shaft 40 on which the blade 1 is rotatably fixed to a main body.
Since it was fixed by 2 and nut 43, holder A4
The method was to fix the holder B42 or the holder B42 and then tighten the nut 43, or vice versa. This holding structure requires a tool for attaching and detaching the blade, and also requires force and takes a long time to attach and detach, which causes great difficulty especially when the worker is old or female.

For the same purpose as the present invention, Japanese Patent Laid-Open Nos. 2-20214 and 3-74218 propose a structure in which an attaching / detaching device is provided at the lower end of the drive shaft. In the case of these prior applications, there is a risk that the attachment / detachment device will become abnormal during operation and the blade will be scattered in the radial direction of the drive shaft at once if the blade comes off. In addition, since the device is in a position where it is directly subjected to the impact of cutting, a considerable weight increase is required to obtain sufficient strength.

[0004]

As described above, according to the conventional attaching / detaching method, a tool is required for attaching / detaching the blade, which causes a problem in force and working time, or in a mower due to an increase in weight of the attaching / detaching device itself. There is a concern that workability will deteriorate. The present invention solves these problems with the following structure.

[0005]

That is, according to the present invention, a holder 2 for supporting a cutting tool 1, a hollow drive shaft 4 through which a shaft 3 fixed to the holder penetrates, and one end of a shaft penetrating the drive shaft are held. A cutter holding structure for a mower, comprising a holding part 5 and a fixing part 6 for fixing the holding part 5.

The holding portion 5 is a rigid ball 7 that fits into a groove 3a provided at one end of the shaft 3 and a housing 8 that holds the rigid ball. The fixing portion 6 presses the rigid ball 7 toward the groove 3a. An L-shaped centrifugal cam lever 12 having an annular slider 9, an operating lever 10 for the slider, and a stopper 11 for the operating lever, or an L-shaped centrifugal cam lever 12 having a holding tooth 5 at one end of the shaft 3 with a fitting tooth portion 12a fitted in the groove 3a. The fixed portion 6 is a weight portion 12b provided at the other end of the L-shaped centrifugal cam lever 12 rotatably supporting the intermediate portion, or the holding portion 5 is provided at one end of the shaft 3. A forked stopper pin 13 and an annular slider 14 that slides outside the tip of the forked stopper pin to prevent the stopper pin from coming off when the stopper pin is opened. Allows shaft release Cam for restricting the movement of the annular slider 14 to push button 15 and the shaft at a fixed
Structures such as 16 are preferred embodiments.

[0007]

With the above structure, the shaft fixed to the holder is passed through the drive shaft, and is held by the holding portion so as to be rotatable and vertically movable above the drive shaft.
As a result, the weight of the device is kept to a minimum by setting the shape of the necessary parts with the minimum strength while keeping the holding part from being directly subjected to the impact of cutting. The holding part can be fixed to the main part of the mower by a fixing part that can be easily operated with little force without using tools. Also, when the shaft penetrates the drive shaft, if the blade part comes off due to some cause in the holding part, the precursor phenomenon is clearly generated for a relatively long time, and the blade part moves in the radial direction of the drive shaft. It is possible to minimize the danger because it has a structure that does not scatter at once and falls downward. By providing these structures, the worker can attach and detach the blade with minimum force and time by releasing the fixing portion without using the tool.

[0008]

【Example】

Embodiment 1 FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 (a) is a view as seen from an arrow P in FIG. 1 (b), and FIG. 1 (b) is a sectional view taken along line XX in (a). Figure 2
(a)-(c) is an expanded sectional view of a holding part. Fig. 3 is Fig. 1 (b)
It is an example of a middle Q section arrow view. Of course, the present invention does not make the fitting of the blade shown in FIG. 3 and the holders A and B an indispensable condition, and the conventional fitting method can be used. In the apparatus of this embodiment, the blade 1 is clamped by the holder block 2a and the holder block 2b from the upper and lower surfaces thereof, and into the rectangular support hole in the center of these blocks, the lower end portion seen in FIG. Are pierced through and serve as a holder 2 for supporting the blade 1.

The shaft 3 has such a length that it penetrates through the hollow drive shaft 4 and reaches the upper holding portion 5. The power transmission mechanism from the prime mover connected to the drive shaft 4 may be substantially the same as the conventional one. The shaft 3 that penetrates the drive shaft 4 is held by a holding portion 5 at the upper end portion. The holding portion 5 has a housing 8 holding a hard sphere 7 that fits into a groove 3a provided at the end of the shaft 3. The housing 8 has a spring 9a
The annular slider 9 biased by is held so as to be movable in the axial direction of the shaft 3. The annular slider 9 is in a state in which the inner diameter is gradually increased toward the end, and pushes the hard sphere 7 toward the concave groove 3a side as it moves toward the tool.

In this example, the fixed portion 6 is formed by recessing the hard sphere 7 into a groove.
It is composed of an annular slider 9 that is pressed toward the 3a side, an operating lever 10 that can manually operate the slider, and a stopper 11 that restrains the operating lever when it is fixed. Operating lever
Reference numeral 10 is pivotally supported by a pin 10a on a casing 30 of the mower, one end of which is connected to a slider 9 and the other end of which has a lever portion which reaches a stopper 11. One end of the stopper 11 is pivotally supported by the casing 30 of the mower, and the lever portion of the stopper 11 can be always locked by the spring 11a to the locking claw portion thereof. To release the fixation, press the stopper 11.

When mounting the blade, first, with the lever 10 aligned with the position A, the shaft 3 of the holder 2 in which the blade 1 is fitted is passed through the drive shaft 4. When the steel ball 7 of the holding part 5 and the shaft 3 come into contact with each other, the steel ball escapes into the clearance S1 of the slider 9 and the shaft can enter the part a as shown in FIG. 2 (a). Next, when the lever 10 is moved to B, the slider 9 rises and the steel ball 7 is pushed out in the shaft direction and fits into the groove of the shaft 3. Further, when the lever 10 is moved to C, a force in the direction a is applied to the shaft by an appropriate elastic force of the lever, and the surface pressure between the blade and the holder increases. In this state, the mounting of the blade is completed by locking the lever at the position D, that is, by locking.

When removing the blade, first, the lever 10 is moved from the position D to the position B. At this time, in the holding portion 5, the slider 9 biased in the b direction by the spring 11a contacts the c surface in the casing 30. When the lever is moved from B to A, the spring 11a is compressed and the steel ball 7 moves to the slider 9
It is discharged into the clearance S1 and the shaft 3 can be pulled out in the b direction.

When the cutter is mounted and working, the holder 5 is fixed to the shaft 3 rotating at a high speed, and therefore the holder rotates at the same high speed as the cutter 1. .. Since the fixed portion 5 and the holding portion 6 are linked through the bearing 17, the drive shaft 4, the shaft 3 and the holder 2 are integrally rotated by proper fitting. High-speed rotation can be continued smoothly.

Embodiment 2 FIGS. 4 and 5 show a second embodiment of the present invention in which the fixing portion is automatically fixed to the main body of the mower by centrifugal force as the blade 1 and the drive shaft 4 rotate. It is a structure that does. In this example, the holding portion 5 is a fitting tooth portion 12 that fits into the concave groove 3a at the upper end of the shaft 3.
a pair of L-shaped centrifugal cam levers 12, 12 having a, 12a,
The fixed portion 6 is a weight portion 12b, 12b provided at the other end of the L-shaped centrifugal cam lever 12, 12 which is axially supported by a support flange 18 which rotates integrally with the drive shaft 4.

FIGS. 4 (a) and 4 (b) show a state in which the holding portion 5 is loosened and the shaft 3 can be freely inserted and removed when the blade 1 and the drive shaft 4 are stopped. Since only a relatively small force generated by the spring 24 is applied to the L-shaped centrifugal cam levers 12, 12, a pair of mating tooth portions 12a, 12 facing each other is formed.
If the upper end of the shaft 3 resists the above-mentioned spring force, it can freely pass between a. Therefore, as shown in (b), when the flexible casing head 19 of the mower is pressed from the outside, the shaft 3 can be pulled out and the blade can be removed.

On the other hand, when the blade is in the rotating state, as shown in FIG.
As shown in (b), as the blade 1 and the drive shaft 4 rotate, the weight portions 12b, 12b provided at the ends of the L-shaped centrifugal cam levers 12, 12 that are the fixed portions 6 are removed by centrifugal force. The fitting tooth portions 12a, 12a are firmly fitted into the recessed grooves 3a formed in the shaft 3 and are restrained while rotating together.

Embodiment 3 FIGS. 6 (a) to 6 (d) show a third embodiment of the present invention. In this example, a push button from the outside is provided as a means for releasing the fixed portion of the shaft. As the holding portion 5, a bifurcated stopper pin 13 is provided on the upper end of the shaft 3, and an annular slider 14 that slides axially outside the tip end of the stopper pin to prevent the stopper pin from coming off when the stopper pin is opened. As shown in (d), the stopper pin 13 has a split on the upper end of the shaft 3 to pivotally support the bifurcated base. Stopper Pin
The tip end of 13 has a stepped portion 13a, and the reduced diameter portion 14a inside the annular slider 14 is engaged when the bifurcated stopper pin 13 is opened (b). The annular slider 14 is always urged toward the upper end of the shaft 3 with a spring 21 interposed between the annular slider 14 and a spring receiver 20 which rotates integrally with the drive shaft 4.

As the fixing portion 6, when pushed, the push button which closes the bifurcated stopper pin 13 from the outside and allows the reduced diameter portion 14a inside the annular slider 14 to pass therethrough to release the shaft 3. There is also a cam for moving the annular slider 14 when the shaft is released.
16 are provided. The push button 15 has a cylindrical shape with a spring 22 interposed above the mower body casing 30. The cam 16 is eccentrically provided on an inner end portion of the casing of a rotation shaft 23a of a lever 23 rotatably provided on the mower body casing 30.

When mounting the blade, first the shaft 3 is inserted into the drive shaft 4 (a). Next, by causing the lever 23, the cam 16 lowers the slider 14 downward against the force of the spring 21 (b). In this state, move the cam 16 to the slider 14
When separated from the shaft, the shaft 3 is held in a state of being urged upward by the force of the spring 21. When removing the blade, the push button 15 is pushed down to close the bifurcated stopper pin 13 (c), and at the same time, the shaft 3 is pulled out from the drive shaft.

[0020]

As described above, the present invention enables an operator to easily attach and detach a blade without using a tool with a small force. In addition, by passing the shaft through the drive shaft,
When the blade comes off due to some abnormality in the holding part, the precursor phenomenon is clear, it occurs for a relatively long time, and
The blade does not scatter in the radial direction of the drive shaft all at once, but it is possible to minimize the risk by making it fall downward.

[Brief description of drawings]

FIG. 1 (a) is a sectional view of a P portion in (b), and FIG. 1 (b) is a sectional view taken along line XX in (a).

2A to 2C are enlarged cross-sectional views of a holding portion.

FIG. 3 is a view on arrow Q in FIG. 1 (b).

FIG. 4A is a view showing a holding portion and a fixing portion, and is a view taken along the line YY in FIG. 4B, and FIG. 4B is a sectional view corresponding to FIG.

5A is a view showing a holding portion and a fixing portion, and is a view taken along the line ZZ in FIG. 5B, and FIG. 5B is a sectional view corresponding to FIG.

6A to 6C are cross-sectional views of a holding portion and a fixed portion, and FIG. 6D is a side view of a stopper pin at the upper end of the shaft.

FIG. 7 is a cross-sectional view of a conventional product.

[Explanation of symbols]

 1 Blade 2 Holder 3 Shaft 4 Drive shaft 5 Holding part 6 Fixed part 7 Hard sphere 8 Housing 9 Slider 10 Operation lever 11 Stopper 12 L-type centrifugal cam lever 13 Stopper pin 14 Slider 15 Push button 16 Cam

Claims (4)

[Claims] 1. A holder 2 for supporting a cutting tool 1, a hollow drive shaft 4 through which a shaft 3 fixed to the holder penetrates, a holding portion 5 for holding one end of the shaft penetrating the drive shaft, and the holding portion 5. A blade holding structure for a mower, comprising a fixing portion 6 for fixing. 2. The holding portion 5 is a rigid ball 7 that fits into a groove 3a provided at one end of the shaft 3 and a housing 8 that holds the rigid ball, and the fixing portion 6 presses the rigid ball 7 toward the groove 3a. The blade holding structure for a mower according to claim 1, comprising an annular slider (9), an operating lever (10) for the slider, and a stopper (11) for the operating lever. 3. The holding portion 5 is an L-shaped centrifugal cam lever 12 having a fitting tooth portion 12a fitted in the groove 3a at one end of the shaft 3, and the fixing portion 6 is rotatably supported in the middle thereof. 2. The blade holding structure for a mower according to claim 1, wherein the weight portion 12b is provided at the other end of the L-shaped centrifugal cam lever 12. 4. The holding portion 5 is a bifurcated stopper pin 13 provided at one end of the shaft 3 and an annular slider 14 which slides outside the tip end portion of the stopper pin to prevent the stopper pin from coming off when the stopper pin is opened. 2. The mower according to claim 1, wherein the portion 6 is a push button 15 that allows the shaft to be released by closing the bifurcated stopper pin 13 from the outside during pushing and a cam 16 that restricts the movement of the annular slider 14 when fixing the shaft. Tool holding structure.