JPH0449868Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention connects the grounding part of the lower end of the case, which is slidably fitted to the bobbin, to the lower end of the fastener, which is fixed to the drive shaft that integrally connects the bobbin. The present invention relates to a cord holding device for a brush cutter in which a bobbin is provided with a slit that allows the cord to protrude further downward and to visually check the remaining state of the cord and the state in which it is wound and held on the bobbin.

[Conventional technology]

Cutters made of flexible materials, so-called brush cutters that pay out a fixed amount of cord from the bobbin for cutting work, have traditionally been equipped with a non-tap-and-go (no-tap) cutter that allows the cord to be fed out without touching the case or bobbin to the ground. There are two types: the tap-and-go type, and the tap-and-go type, in which when the bobbin touches the ground, the bobbin itself moves up and down, disengaging from the case and allowing the cord to be fed out.

In the case of the type (), for example, a bobbin with a wound cord is fitted onto a brush cutting shaft driven by a prime mover, while a bobbin holding plate can be attached to and removed from the cutting shaft using a fastener. A brush cutter has been proposed that can prevent the cord from unintentionally loosening from the bobbin by attaching the cord to the bobbin and using the fastener to project the lower outer peripheral edge of the bobbin holding plate downward.
(See Jitsumeikai Publication No. 60-31227 for an example) ()
In the case of the type shown in FIG. 6, for example, as shown in FIG.
A lid body 4, which has a flat U-shaped cross section and fixes a grommet 3 to the outer peripheral edge, is connected to the case 2, which is integrally assembled with the case 2. ) A bobbin 6 having a substantially H-shaped cross section and having a protrusion 5 that can be freely engaged and detached is slidably fitted onto the outer circumferential edge of a cylindrical portion 7 that hangs down from the center of the case 2. The bobbin 6 is always urged and biased downward by a coil spring 8 stretched inside, and the case 2, cover body 4, and bobbin 6 rotate integrally during mowing work, and the bobbin 6 is rotated as a unit. When the cord 10 laminated and wound around the periphery is cut, if the bottom part 9 of the bobbin 6 hits the ground, the bobbin 6 rises inside the case 2 and the protrusion 5 comes off the locking piece, leaving the bobbin in a free state. A brush cutter has been proposed in which a cord 10 can be fed out from a grommet 3 by rotating the cord 6.

() Furthermore, a brush cutter has been proposed in which a cord wound around a bobbin can be fed out by mutually engaging and disengaging engagement pieces attached to the case and the bobbin, respectively.
(See Japanese Patent Application Publication No. 55-21793 for an example.) [Problem to be solved by the invention] In the above-mentioned conventional technology, in the form of (), when cutting the cord, after temporarily interrupting the bobbin, Since the cord is fed out by the operator, it is difficult to handle the cord during brush cutting work, and it is difficult to expect an improvement in work efficiency.In addition, since the cord feeding out port changes, the area where the cord is cut is the same as when cutting the cord. There is a disadvantage that it requires time and effort to set a newly fed cord at a location, and when the cord is cut repeatedly, in addition to the above-mentioned labor, a great deal of time is wasted.

In the case of the type (), although the cord 10 is automatically fed out, since the bottom part 9 serving as the grounding part is relatively narrow at the center of the bobbin 6, it is difficult to expect constant grounding under uniform conditions. It is not always sufficient from the standpoint of stability during work, and the cord 10 wound around the bobbin 6 gradually loosens due to repeated contact of the bottom 9 of the bobbin 6 with the ground, so when the cord 10 is fed out, the cord 10 near the grommet 3 There is a risk of mutual entanglement.

Furthermore, in the case of the type (), the cord is automatically fed out from the bobbin as in both cases, but the actuation of the engaging piece as the case rotates is caused by the engaging piece on the bobbin side. If there is a slight difference, the cord will not be transmitted reliably and there is a risk that the cord will not be paid out the appropriate length from the bobbin, making it difficult to perform sufficient mowing work with the cord that has been paid out, and the feeding mechanism itself may be complicated. Therefore, there is a drawback that there is a concern that the bobbin, case, engagement piece, etc. may not operate properly during the mowing operation.

Furthermore, in any of the above-mentioned formats (), (), and (), there is no through hole or viewing window in the case, so it is not possible to accurately grasp the remaining state of the cord in the case, winding/retention state, etc. This has the disadvantage that the cord runs out during mowing work, forcing the work to be abruptly interrupted.

This invention was proposed in view of the above-mentioned drawbacks, and its purpose is to
By constantly and evenly striking the ground contact part of the case against the ground, the cord is reliably fed out from the same outlet, and the state of the cord remaining in the case, winding and holding state, etc. can be checked. It is an object of the present invention to provide a cord holding device for a brush cutter that can be grasped accurately.

[Means to solve the problem]

In order to achieve the above-mentioned purpose, the cord holding device for a brush cutter according to the present invention is provided in a brush cutter in which a bobbin on which a cord is wound is integrally assembled to a drive shaft driven by a prime mover, and an upper disc with a slit is provided. A boss portion integrally formed in the center of the part and integrally connected to and penetrated by the drive shaft, and a boss portion formed around this boss portion,
a bobbin having a cylindrical cord winding portion that covers the periphery of a downwardly open annular space; a bobbin that is penetrated by the drive shaft below the boss and is integrally fastened below with a fastener; and a presser piece that stands up toward the annular space and has an appropriate number of claws protruding radially upward, and a presser piece that loosely surrounds the outer periphery of the upper disc part and has grommets attached to the side edges. a cylindrical part; an inner cylindrical part that stands up in an annular space and has a protrusion directed inward above the presser piece and is provided with a locking piece that is removable from the claw; a case in which the lower portions of each of the outer cylinder portions are integrally connected below and a grounding portion is formed in a curved manner downward from the lower end of the fastener;
It consists of a resilient body that is stretched across the annular space and the inside of the inner cylindrical portion between the upper disk portion and the protrusion, and constantly resiliently urges the case downward.

〔Example〕

An embodiment of this invention will be described below with reference to FIGS. 1 to 5. This invention consists of the main members of a bobbin B, a case C, a presser piece 11, and a bullet body 18, which will be described later. A square portion, for example a hexagonal portion, formed on the inner peripheral edge of the protrusion P at the upper end of the presser piece 11 (in FIG. 1) is coated on the boss portion r of the lower part of the bobbin B (in FIG. 1), which has a substantially T-shaped cross section.
At the same time, a male screw S ₁ cut into the lower part of the drive shaft 13 passing through the through hole i of the bobbin B and the presser piece 11 is inserted.
The fastener 12, for example, screws together the female thread n of a wing nut.
While tightening the presser piece 11 to set and hold it at a fixed position relative to the drive shaft 13, the middle of the drive shaft 13 is passed through the square part 14 formed at the center of the upper end of the bobbin B.
This drive shaft 1 is fitted and integrally connected.
A drive member rotated by a prime mover (not shown), such as an engine, is screwed into the male screw S ₂ carved above 3.
By tightening the bobbin B, presser piece 11, and drive shaft 1
3 can be rotated integrally. The protrusion P
As shown in Fig. 4, a suitable number (six in this case) of claws a ₁ , a ₂ , etc. are protruded radially from the outer periphery at equal intervals, and these claws a ₁ , a _{2 ,} etc. are engaged with each other. A grommet 15 is attached above the outer cylindrical part f of the case C, in which removable locking pieces e are made to protrude into the inner cylindrical part v at regular intervals. At the same time, as shown in FIG. 1, the lower parts of the outer cylinder part f and the inner cylinder part v are integrally connected to each other, and a cross section is formed downward from the lower end of the fastener 12. is curved and protruded into a substantially semicircular arc shape to form a grounding portion g. Further, a flexible cutter made of synthetic resin, the so-called cord 19, is wound and held in a laminated manner on the outer peripheral edge of a cylindrical cord winding part d which can hang down integrally with the upper disc part 17 of the bobbin B. , an annular space k is formed below the upper disc part 17 at the inner peripheral edge of the cord winding part d, and extends between the annular space k and the upper inner side of the inner cylinder part v, and between the upper disc part 17 and the projection part 16. An elastic body 18, such as a coil spring, is stretched to constantly elasticize and urge the case C downward, while at the same time, the upper disk portion 17 fits loosely near the upper end of the case C at the appropriate position. The cord 19 is provided with a slit 20 so that the remaining state of the cord 19 and the winding/holding state on the bobbin B can be easily grasped during mowing work. In the figure, h is a blank space in case C.

[Effect]

In this invention, the drive shaft 13 is activated by starting the prime mover.
When rotates, bobbin B, presser piece 11, case C
The three members rotate together under one body, and the cord 19 fed out to the outside of the case C performs the desired mowing operation. Therefore, when cutting the cord 19, the grounding part g of the case C
When you hit the ground with this, case C itself will be fired by projectile 18.
The case C rises along the drive shaft ₁₃ against the elastic force of
3, and because it rotates around the drive shaft 13 slower than the bobbin B due to the resistance caused by contact with the ground, the cord 19 is fed out from the grommet 15 by a certain length to the outside of the case C. nail
When the locking piece e released from the engagement with _a1 rotates in the direction of _the arrow (counterclockwise) in FIG. The elastic force of the projectile body 18 pushes and lowers the case C toward the holding piece 11 again, and the locking piece e is locked to the claw _a2 located in the immediate vicinity of the claw _a1 through the space h. ,
Case C is integrally combined with bobbin B, and bobbin B
The code 1 rotates at the same speed as the newly released code 1.
At step 9, the desired mowing operation is performed. Thus code 19
Each time the mowing work is cut, the cord 19 is automatically fed out to the outside of the case C through the grommet 15 by the strong impact of the grounding part g on the ground, so that the mowing work can be continued without interruption.

〔effect〕

According to this invention, since a slit is provided in the upper disc part of the bobbin, the operator (not shown) can easily grasp the remaining state of the cord and the state of winding and holding on the bobbin during mowing work. The mowing work can be continued with peace of mind without the risk of being forced to interrupt the mowing work unexpectedly, and the repetitive work of cutting weeds, lawns, etc. using synthetic resin cords will not cause shock tension. Frictional heat is generated between the cords wound around the bobbin, which may cause the cords to weld together.However, due to the presence of the slits, outside air flows into the bobbin and cools the inside of the bobbin. , it is possible to prevent a temperature rise due to the generation of frictional heat. In addition, since the grounding part is curved and protrudes downward from the lower end of the fastener, there is no risk of the fastening being loosened or damaged even if the grounding part hits the ground. bobbin,
There is no fear that the presser piece etc. will be damaged by unexpected shocks or vibrations, the cord will loosen from the bobbin and will not become entangled with each other, and the grounding part is integrated below the inner and outer cylinder parts of the case. Since the projecting body is connected to the drive shaft, it can strike the ground evenly and reliably, maintaining a more stable state compared to the striking of the ground with conventional brush cutters. The upper portion of the bobbin, which extends between the annular space around the boss portion and the inside of the inner cylinder portion of the case, and between the upper disk portion and the protrusion portion located above the presser piece on the case side, and is integral with the drive shaft. Since the case is loosely fitted to the outer periphery of the disc part, there is no problem when the ground contact part hits the ground and expands and contracts as it is released, so the case itself can be moved up and down smoothly. Since the presser piece is held in a fixed position on the drive shaft by the fastener, the claw that can protrude from the protrusion of the presser piece is always engaged and held by the locking piece on the inner periphery of the case, and the The locking piece rotates with the case as the bang is released, and when the hard hit is released, the locking piece is securely locked to the nearest pawl, and the case rotates at the same speed as the bobbin, so the cord is only a certain length. By making it possible to automatically and reliably feed out the grass, the mowing work can be continued, and an improvement in work efficiency can be expected.

[Brief explanation of drawings]

Figure 1 is a sectional view taken on line -0- of Figure 2 of the proposed product, Figure 2 is a plan view, Figure 3 is a bottom view of Figure 1,
Figure 4 is a view taken along the - line in Figure 1, and Figure 5 is a view of Figure 1.
The left side view of the figure and FIG. 6 are longitudinal cross-sectional views of a conventional tap-and-go type brush cutter. B...Bobbin, C...Case, _a1 , _a2 ...Claw,
d... Cord winding part, e... Locking piece, f... Outer cylinder part, g... Grounding part, k... Annular space, r... Boss part, v... Inner cylinder part, 11... Holding piece, 12... Fastener, 13... Drive shaft, 15... Grommet, 1
6...Protrusion, 17...Upper disc, 18...Bullet body, 19...Cord, 20...Slit.

Claims (1)

[Scope of utility model registration request] In a brush cutter in which a bobbin with a cord wound around it is integrally assembled to a drive shaft driven by a prime mover, it is integrally formed in the center of an upper disk portion with a slit, and is integrally connected to and penetrated by the drive shaft. The boss part and
A bobbin includes a cylindrical cord winding part formed around the boss part and covering the periphery of a downwardly open annular space, and a bobbin that is penetrated by the drive shaft below the boss and integrally extends downward. Fastened with fasteners,
and a presser piece that stands up toward the annular space and has an appropriate number of claws radially projecting upward, and an outer cylinder that loosely surrounds the outer periphery of the upper disc part and has grommets attached to the side edges. and stand up within the annular space,
An inner cylindrical portion is formed with an inward protrusion above the holding piece, and an inner cylindrical portion is provided with a locking piece that can be releasably engaged with the claw, and the lower portions of the inner cylindrical portion and the outer cylindrical portion are integrally connected to each other. and a case having a grounding part formed in a curved manner protruding downward from the lower end of the fastener, and a case extending between the upper disc part and the protrusion extending across the annular space and the inside of the inner cylinder part, and A cord holding device for a brush cutter consisting of a projecting body that constantly projects and urges downward.