JP2024046269A - Grass-cutting cord unwinding device - Google Patents

Abstract

[Problem] To provide a grass-cutting cord unwinding device that has a reduced thickness and that winds the mowing cord around the mowing cord beforehand and that unwinds the mowing cord when the mowing cord becomes worn. [Solution] A grass-cutting cord unwinding device 1 has a case 14 with a through hole for passing the mowing cord through, a reel section for winding the mowing cord around it, and a number of springs for biasing the reel section, the reel section being built into the case, the top of the reel section being exposed to the outside of the case and having a shape that allows the tip of a brush cutter to be connected to the top, a lock section being provided on the inner surface of the reel section and the case, the lock section restricting the rotation of the reel section in the direction in which the mowing cord is unwound, and the reel section being provided with a through hole for the mowing cord that passes through the reel section in a direction intersecting the axial direction of the reel section, the through hole being provided so as to pass between the springs. [Selected Figure] Figure 1

Description

The present invention relates to a grass cutting cord payout device.

As shown in Patent Document 1, a mowing cord feeding device includes a reel member, a pressing part, a coil spring disposed between the pressing part and the cap, and a case housing the coil spring and the reel member. It has been known. This device is attached to the tip of a brush cutter using a hole provided in the cap. The pressing portion is exposed to the outside of the case from the bottom of the case. By pressing the pressing part against the ground, the reel member is rotated and the mowing cord wound around the reel member is let out.

Japanese Patent No. 4504659

In a cord-type brush cutter, the mowing cord gradually wears out during the mowing process, becoming worn or torn. In the device of Patent Document 1, the mowing cord is wound around a reel member in advance, and when the mowing cord wears out, the worn mowing cord can be replaced by unwinding the mowing cord from the reel member.

In the device of Patent Document 1, a coil spring is provided above the pressing part, which tends to make the device thicker. If the device is too thick, it is necessary to mow the grass with the main pipe of the brush cutter raised high above the ground. If the device is too thick, it is easy to become tired when operating the brush cutter. In addition, if the device is too thick, there is the problem that it is bulky during transportation and storage.

The present invention aims to provide a grass-cutting cord reeling device that has a reduced thickness and that reels out the grass-cutting cord when the grass-cutting cord becomes worn out.

This is a mowing cord feeding device that is attached to the tip of a brush cutter, and consists of a case provided with a through hole through which the mowing cord is passed, a reel portion for winding the mowing cord, and the reel portion. The reel is built into the case, and the top of the reel is exposed outside the case, and the tip of the brush cutter can be connected to the top. A locking portion is provided on the reel portion and the inner surface of the case, and the locking portion restricts rotation of the reel portion in the direction in which the mowing cord is fed out, and resists the biasing force from the spring. By displacing the reel part, the restriction in the lock part is released, and the reel part is provided with a through hole for a mowing cord that passes through the reel part in a direction intersecting an axial direction of the reel part. The above problem is solved by a mowing cord feeding device provided so that the through hole passes between the plurality of springs.

In the above device, the reel section is configured such that the reel section is biased not by a single spring but by a plurality of springs, and the through hole for the mowing cord passes between the plurality of springs. There is. With this configuration, it is possible to reduce the thickness of the device by avoiding a layout in which the spring overlaps above or below the reel portion.

The device preferably further includes a seat that rotatably supports the multiple springs, and the seat rotates to rotate the reel unit during the unwinding process. This prevents the springs from falling off and allows the reel unit to rotate smoothly.

In the device, it is preferable that the inner surface of the catch and the case is provided with a protrusion and a groove for receiving the protrusion along the rotating direction of the catch. According to this configuration, when the reel portion rotates, it is possible to prevent the position of the catch from shifting.

In the above device, the locking portion can be shaped to have multiple protrusions that have a surface that is inclined with respect to the rotation direction of the reel portion and a surface that is perpendicular to the rotation direction of the reel portion, and are continuous in the rotation direction of the reel portion.

In the device, the upper edge of the case may have a plurality of protrusions each having a ridge line extending radially inward of the case in the direction of rotation of the case. This can prevent grass from becoming entangled with the drive shaft at the tip of the main pipe of the brush cutter.

In the device, it is preferable that the case has an upper case and a lower case, and that the upper case and the lower case are configured to be engageable or disassembleable.

In the device, it is preferable that the bottom portion of the case has a flat shape. By making the bottom portion flat, the device can be made thinner. Furthermore, when pressing the device against the ground, the posture of the device becomes easier to stabilize.

In the above device, when the bottom of the case is pressed against the ground, the reel part descends and the lock part is unlocked, and the blade is wound around the reel part by the centrifugal force when the reel part is rotated by the power of the brush cutter. It is preferable that the mowing cord is fed out.

In the device, it is preferable that another locking part different from the locking part is provided on the underside of the reel and the inner surface of the lower side of the case, and that the rotation of the reel part in the direction of unwinding the grass cutting cord is restricted by the other locking part. This makes it possible to stop the unwinding of the grass cutting cord, for example, by pressing the device firmly against the ground.

According to the present invention, it is possible to provide a mowing cord feeding device in which a mowing cord is wound in advance and when the mowing cord is worn out, the mowing cord is fed out to mow the grass, and the thickness of the device is reduced. I can do it.

FIG. 1 is a perspective view showing an embodiment of a grass cutting cord unwinding device. 2 is a perspective view showing the grass mowing cord reeling device of FIG. 1 as viewed from below. FIG. FIG. 2 is a sectional view of the mowing cord feeding device of FIG. 1; 2 is a perspective view showing the grass mowing cord payout device of FIG. 1 in an exploded state as viewed from above. FIG. FIG. 2 is an exploded perspective view of the mowing cord feeding device of FIG. 1 viewed from below. 2 is a perspective view showing the grass mowing cord reeling device of FIG. 1 with an upper case, a reel unit, and a spring removed; FIG. FIG. 2 is a perspective view showing a reel unit incorporated in the mowing cord feeding device of FIG. 1 as viewed from below. FIG. 3 is a cross-sectional view schematically showing the state of the first lock portion and the second lock portion in a state where the mowing cord feeding device is not pressed against the ground. FIG. 3 is a cross-sectional view schematically showing the state of the first lock part and the second lock part in a state where the mowing cord feeding device is pressed against the ground. 10 is a cross-sectional view showing a schematic state of the first locking portion and the second locking portion when the grass mowing cord payout device is pressed more firmly against the ground. FIG. FIG. 7 is a sectional view showing another embodiment of the mowing cord feeding device.

The following describes an embodiment of the mowing cord payout device (hereinafter, sometimes simply referred to as the device) of the present invention. The embodiments and usage examples shown below are merely limited examples of the present invention, and the technical scope of the present invention is not limited to the exemplified embodiments.

[First embodiment]
1 to 10 show an apparatus according to a first embodiment.

The device 1 of this embodiment is a mowing cord feeding device that is attached to the tip of a brush cutter. Although the method and structure for attaching it to the tip of the brush cutter are not particularly limited, in the device 1, as shown in FIG. A power shaft 91 protruding from a gear case provided at the tip of the shaft is fixed. In the example of FIG. 1, a first fixture 12 having a through hole 121 and a second fixture 13 are fixed to the recessed hole 112 of the reel portion 11. The power shaft 91 is fixed to the second fixture 13. When mowing grass with a brush cutter, the case 14 rotates counterclockwise as shown by the arrow in FIG. (FIG. 2) also rotates together with the case 14. Grass is mowed by bringing a rotating mowing cord 92 into contact with the grass.

As shown in FIG. 3, the device 1 includes a case 14 provided with a through hole 93 through which a mowing cord 92 is passed, a reel portion 11 for winding the mowing cord 92, and a reel portion 11 that extends upwardly. It has a plurality of springs 15 that bias toward the same direction.

The reel unit 11 is built into the case 14 as shown in FIG. 3, and the top 111 of the reel unit 11 is exposed to the outside of the case, and is shaped so that the tip of the brush cutter can be connected to the top 111. As shown in FIG. 8 and other figures, a locking portion 81 is provided on the inner surface of the reel unit 11 and the case 14. The locking portion 81 restricts the rotation of the reel unit 11 in the direction in which the grass cutting cord 92 is unwound, and the restriction by the locking portion 81 is released by displacing the reel unit 11 against the bias of the spring 15. As shown in FIG. 3 and FIG. 7, the reel unit 11 is provided with a through hole 151 for the grass cutting cord 92 that penetrates the reel unit 11 in a direction that intersects with the axial direction. The through hole 151 is linear to make it easier to pass the grass cutting cord through, and is provided so as to pass between the multiple springs 15.

As shown in FIG. 3, the reel unit 11 has a cylindrical upper portion and a thread winding portion 155 provided on the side peripheral surface of the reel unit 11. The upper cylindrical portion is made of a plate material and is hollow inside. The bottom of the reel unit 11 is open. The thread winding portion 155 is made of a plurality of flanges provided on the peripheral portion of the reel unit 11. As described above, the reel unit 11 is provided with a through hole 151 for the grass cutting cord 92 that passes through the reel unit 11 in a direction intersecting the axial direction of the reel unit 11. The through hole 151 is made of a tube 152 that extends in a direction intersecting the axial direction of the reel unit 11. The tube 152 is formed integrally with the top portion 111, for example, by molding the tube 152 and the reel unit 11 integrally with plastic. The through hole 151 is provided so as to open into the inside of the flange of the thread winding portion 155. The amount by which the top of the reel section 11 protrudes from the case 14 can be changed as needed.

As shown in FIG. 3, the hollow reel section 11 has a plurality of fixing parts 153 for the springs 15 on the back surface of the top. The fixing parts 153 are X-shaped protrusions formed by two plates crossing each other at right angles, and are shaped so that the ends of the coil springs can be fitted onto them. Some of the fixing parts 153 have walls 154 shaped to fit the outer shape of the coil springs. When the upper end of the spring 15 is fixed to the fixing parts 153, the upper end of the spring 15 is below the back surface of the top 111, above the thread winding part 155, and above the through hole 151. This results in at least a portion of the spring 15 being stored inside the reel section 11. The thickness of the device 1 is reduced by the amount of the spring 15 stored.

As shown in Figures 4 and 5, the upper surface of the upper flange of the reel unit 11 is provided with a number of protrusions 811 that constitute the locking portion 81, as described above. The protrusions 811 are arranged circumferentially. The locking portion 81 is referred to as the first locking portion 81. A protrusion 812 that constitutes the first locking portion 81 is also provided on the inner surface of the upper case 141 at a position that corresponds to the protrusion 811 when the reel unit 11 is built into the case 14.

As shown in FIG. 5, a plurality of protrusions 821 forming a lock portion 82 different from the first lock portion 81 are provided at the bottom of the central portion of the reel portion 11. The plurality of protrusions 821 are arranged circumferentially. This lock portion 82 is referred to as a second lock portion 82. Also on the inner surface of the lower case 142, as shown in FIG. 4, a protrusion 822 constituting the second lock part 82 is provided at a position corresponding to the protrusion 821 when the reel part 11 is built into the case 14. It will be done. The second lock portion 82 provided at the bottom of the central portion of the reel portion 11 is provided at the lower end of a circular wall protruding from the top portion 111 toward the lower case 142, as shown in FIG. Note that the protrusion constituting the second lock portion may be provided on the lower surface of the flange on the lower side of the reel portion. In this case, the protrusion on the lower case may also be provided at a corresponding position.

The case 14 has a hollow part, which houses a plurality of springs 15, a reel part 11, etc., and has a flat shape with a larger diameter than its thickness. The case 14 is approximately circular in plan view or bottom view. The upper surface of the case 14 is provided with an opening that communicates with the hollow portion. The top portion 111 of the reel portion 11 is exposed to the outside of the case through the opening.

The case 14 includes an upper case 141 and a lower case 142. Upper case 141 and lower case 142 are configured to be engageable or disassembleable. As shown in FIGS. 4 and 5, a plurality of fixing projections 4 and 5 are provided on the inner surface of the upper case 141 and the inner surface of the lower case 142. The protrusion 4 is provided on the inner surface of the upper case, protrudes toward the lower case 142, and has a protrusion 41 and a groove 42 that extend in the circumferential direction of the upper case 141. The protrusion 5 has a protrusion 51 extending in the circumferential direction of the lower case and a protrusion 52 extending from the end of the protrusion 51 toward the bottom of the case 14 .

When the lower case 142 and the upper case 141 are combined and the lower case 142 or the upper case 141 is rotated in the circumferential direction, the protrusion 41 of the protrusion 4 closes the gap between the protrusion 51 of the protrusion 5 and the bottom. and comes into contact with the protrusion 52 of the protrusion 5. As a result, the upper case 141 and the lower case 142 are engaged with each other, that is, are combined. When separating, lower case 142 or upper case 141 is rotated in the opposite direction. The protrusion 52 is provided so as to restrict rotation of the protrusion 41 of the upper case 141 when the upper case 141 is rotated together with the lower case.

The lower case 142 includes a side wall portion 53 that projects upward. The upper case includes a side wall portion 43 that projects downward. The side wall portion 53 and the side wall portion 43 accommodate the reel portion 11 inside the case 14 and protect it from dust, water, and the like.

A metal fitting 94 having a through hole 93 with an inner diameter suitable for inserting the grass cutting cord 92 is attached to the side wall 53 of the lower case 142. A notch 95 corresponding to the metal fitting 94 is provided in the side wall 53. The metal fitting 94 is fixed to the lower case by inserting the protrusion of the metal fitting 94 along the groove provided in the notch 95. The metal fitting 94 is made of a metal material and is configured to be resistant to wear caused by the grass cutting cord.

As shown in FIG. 1, the upper edge of the case 14 has a first ridge line 711 extending radially outward of the case 14 and an arc-shaped ridge line 711 extending radially inwardly of the case in the direction of rotation of the case. A plurality of protrusions 71 having second ridge lines 712 are provided. As indicated by the arrow in FIG. 1, when cutting grass with the brush cutter, the case 14 rotates counterclockwise as described above. At this time, the grass contacts the second ridge line 712 and is repelled away from the center of the case 14. This can prevent grass from becoming entangled with the drive shaft at the end of the main pipe of the brush cutter. Note that the second ridge line may have any shape as long as it can repel grass, and may be a straight line, for example.

As shown in FIG. 4, a plurality of protrusions 822 constituting the second locking portion 82 are provided in the center of the lower case 142. The plurality of protrusions 822 are arranged in a circular shape. A circular groove 83 is provided around the plurality of protrusions 822 provided on the lower case 142 so as to surround the protrusions 822. A receiving seat 61 having a protruding strip 611 on its bottom surface that fits into the groove 83 and slides within the groove is placed on the groove 83. A plurality of protrusions 612 for fixing the spring are formed on the upper surface of the receiving seat 61. The protrusions 612 are cylindrical and suitable for fitting the lower end of the coil spring. When changing the position of the protrusions 821 of the second locking portion 82 as described above, the position of the protrusions 822 is also changed. Alternatively, a protruding strip may be provided on the inner surface of the lower case, and a groove may be provided on the receiving seat.

As shown in FIG. 6, the seat 61 is a ring-shaped member made of a flat plate, and rotatably supports a plurality of springs. When the mowing cord 92 is fed out from the reel part 11, as shown by the arrow in FIG. A plurality of springs 15 whose other ends are supported by the reel portion rotate together. This prevents the spring 15 from bending or one end or the other end of the spring 15 from falling off when the reel portion 11 rotates. Further, the rotation of the reel portion 11 becomes stable and smooth. Note that the catch is not limited to a ring-like flat plate-like shape, but may have any shape as long as it is in contact with the inner surface of the lower case and can support the spring. For example, the seat may be plate-shaped without a through hole. Note that the catch seat 61 rotates in the opposite direction when winding the mowing cord 92.

As shown in Figs. 4 and 6, a plate-shaped rotating part 8 that can rotate freely independently of the lower case 142 is fixed to the bottom of the lower case 142. A fixing protrusion 41 is provided on the upper surface of the rotating part 8, and the protrusion 41 is inserted into a circular hole in the ring-shaped spacer 42 and a hole provided in the center of the lower case 142. The horizontally extending protruding piece of the protrusion 41 is inserted into the hole of the plate-shaped fixing part 43, and the fixing part 43 is rotated horizontally to fix the rotating part 8 to the lower case 142. A protrusion of a stopper member 44 is inserted into the hole of the fixing part 43 to prevent the rotating part 8 from accidentally falling off. A protrusion that restricts the rotation of the protruding piece of the protrusion 41 is provided adjacent to the hole on the plate-shaped fixing part 43.

The bottom surface of the case 14 is flat. This allows the protruding pressing portion to be omitted, making the device 1 thinner. In addition, because the bottom surface of the case 14 is flat, when the device 1 is pressed against the ground to pay out the grass cutting cord 92, the position of the device 1 is more likely to be stable.

Figures 8 to 10 show the protrusions 811 and 812 that make up the first locking part 81, and the protrusions 821 and 822 that make up the second locking part 82. These protrusions are all arranged in a circular shape, so strictly speaking, they do not have the shapes shown in Figures 8 to 10, but for the sake of explanation, they have been simplified as shown in Figures 8 to 10. As shown in Figure 8, the first locking part 81 and the second locking part 82 have a shape in which multiple protrusions having a surface that is inclined with respect to the rotation direction of the reel part 11 and a surface that is perpendicular to the rotation direction of the reel part 11 are connected in the rotation direction of the reel part. In Figures 8 to 10, the direction in which the grass cutting cord is unwound is indicated by an arrow marked with D1, and the direction in which the grass cutting cord is wound is indicated by an arrow marked with D2. D1 is counterclockwise, and D2 is clockwise.

The protrusion 812 of the first locking portion 81 provided on the upper case 141 slopes downward toward D1. The protrusion 811 of the first locking portion 81 provided on the reel portion 11 slopes upward toward D1. The protrusion 821 of the second locking portion 82 provided on the reel portion 11 slopes upward toward D1. The protrusion 822 of the first locking portion 81 provided on the lower case 142 slopes downward toward D1.

When the device 1 is not pressed against the ground, as shown in FIG. 8, the vertical surface of the projection 811 and the vertical surface of the projection 812 are in contact with each other, and the rotation of the reel portion 11 in the D1 direction is restricted. The feeding of the mowing cord 92 from the reel unit 11 is restricted. Mowing work is performed in the state shown in FIG. 8 in which the first lock portion 81 is locked. The first locking part 81 locks the reel part 11 and the case 14 so that they cannot rotate, and the reel part 11 and the case 14 rotate together with the power output from the brush cutter.

When the device 1 is pressed against the ground, as shown in FIG. The engagement relationship between the vertical surface of the protrusion 812 and the vertical surface of the projection 812 is released. As a result, when the first lock part 81 is unlocked and the reel part 11 is rotated by the power of the brush cutter, the case 14 does not rotate, and only the reel part 11 rotates. The mowing cord wound around the reel part 11 can be let out by using the centrifugal force caused by the rotation of the reel part 11.

To stop the grass cutting cord from being unwound, the power of the brush cutter should be stopped. However, even if the power of the brush cutter is stopped, the reel unit 11 continues to rotate due to inertia depending on the rotation speed. By pressing the device 1 further against the ground, the reel unit 11 further descends against the spring force of the spring 15 with respect to the upper case 141 and the lower case 142, and as shown in FIG. 10, the vertical surface of the protrusion 821 and the vertical surface of the protrusion 822 engage with each other. This stops the rotation of the reel unit 11 due to inertia, and the grass cutting cord 92 can be forcibly stopped from being continuously released due to inertia. Once the rotation of the reel unit 11 due to inertia has stopped, the device 1 can be removed from the ground, and the reel unit 11 will rise due to the spring force of the spring 15, and the first lock unit 81 will return to the locked state.

The mowing cord 92 may be unwound manually, without relying on the power of the brush cutter, by repeatedly pressing the device 1 against the ground and then lifting it off the ground. By repeatedly performing this operation, the reel unit 11 can be rotated in the D1 direction by utilizing the sliding of the protrusions 811 and 812 of the first locking unit 81 on the inclined surfaces and the sliding of the protrusions 821 and 822 of the second locking unit 82 on the inclined surfaces. To achieve this purpose, the tops of the protrusions 811 and 812 of the first locking unit 81 and the tops of the protrusions 821 and 822 of the second locking unit 82 are positioned offset from each other in the direction of rotation of the reel unit.

When loading the mowing cord 92 into the device 1, the mowing cord 92 is inserted through the through hole 93 of the case 14 and the through hole 151 of the mowing cord 92. The user can wind the mowing cord 92 around the reel portion by rotating the reel portion 11 in the D2 direction while pushing in the top portion 111 with their hand or the like.

In the device 1, the rotating portion 8 of the lower case 142 rotates independently. Therefore, for example, even if the device 1 is pressed against the ground while the case 14 is rotating, the rotating part 8 will only come into contact with the ground, and the rotation of the lower case 142 will not be transmitted to the ground. When the device 1 is pressed against the ground, it is difficult for the device to swing greatly due to the power of the brush cutter, and stones are not easily thrown away by the rotation of the lower case 142.

[Second embodiment]
The device 1b of the second embodiment differs from the device 1 only in the configuration of the lower case 142b. The lower case 142b of the device 1b does not have a rotating part. The device 1b has a small number of parts, is relatively lightweight, and can be manufactured at low cost.

Reference Signs List 1 Grass-cutting cord unwinding device 1b Grass-cutting cord unwinding device 92 Grass-cutting cord 14 Case 141 Upper case 142 Lower case 11 Reel portion 15 Spring 81 Lock portion 82 Lock portion 61 Receptacle 611 Convex strip 83 Concave groove 71 Protrusion

Claims (9)

This is a grass cutting cord payout device that is attached to the tip of a brush cutter.
The device has a case having a through hole through which the grass-cutting cord passes, a reel unit for winding the grass-cutting cord, and a plurality of springs for biasing the reel unit,
the reel unit is built into the case, the top of the reel unit is exposed to the outside of the case, and the top of the reel unit is configured to be connectable to a tip of a brush cutter;
The reel and the inside of the case are provided with locking parts.
The locking portion restricts rotation of the reel portion in the direction in which the mowing cord is paid out, and the restriction by the locking portion is released by displacing the reel portion against the bias of the spring,
The reel section is provided with a grass-mowing cord passage hole that passes through the reel section in a direction intersecting the axial direction of the reel section, and the passage hole is arranged to pass between the multiple springs. The spring further includes a seat for rotatably supporting the plurality of springs,
2. The grass mowing cord reeling device according to claim 1, wherein, during the reeling, the receiving seat rotates to rotate the reel portion. The mowing cord feeding device according to claim 2, wherein the inner surface of the catch and the case is provided with a protrusion and a groove for receiving the protrusion along the rotating direction of the catch. 1. The locking portion has a shape in which a plurality of protrusions are continuous in the rotational direction of the reel, each having a surface inclined with respect to the rotational direction of the reel and a surface perpendicular to the rotational direction of the reel. Or the mowing cord feeding device according to 2. A grass cutting cord payout device according to claim 1 or 2, in which the upper edge of the case is provided with a plurality of protrusions having ridges that extend radially inward of the case in the direction of rotation of the case. The grass cutting cord unwinding device according to claim 1 or 2, wherein the case has an upper case and a lower case, and the upper case and the lower case are configured to be engageable or disassembleable. The mowing cord feeding device according to claim 1 or 2, wherein the bottom portion of the case has a flat shape. When the bottom of the case is pressed against the ground, the reel descends and the lock is released, and the centrifugal force generated when the reel is rotated by the motive power of the brush cutter releases the mowing cord wound around the reel. The mowing cord feeding device according to claim 1 or 2, wherein a mowing cord is fed out. A lock part different from the lock part is provided on the lower surface of the reel and the lower inner surface of the case,
3. The grass mowing cord reeling device according to claim 1, wherein the other locking portion restricts rotation of the reel portion in the direction in which the grass mowing cord is reeled out.

Images