JPH07108521B2 - Tightening device for chains of chainsaws - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sword-shaped saw portion which is held by tightening an end portion between a casing for receiving a drive engine and a tightening element, and when the tightening element is loosened. A sword-shaped saw is movable in the vertical direction, and for this movement, a rotatable disk having a slider having a pin protruding laterally with respect to the moving direction and a curved guide groove with which the pin engages. And a fastening device for a chain that moves a sword-like saw part of a power chainsaw, which is provided with.

[0002]

BACKGROUND OF THE INVENTION Canadian Patent No. 1106264 essentially comprises a slider and a rotatable disc,
A power chain saw is described which has a fastening device in which the slider engages a sword-like saw. The slider has a pin that projects into the curved guide groove of the disc, which causes the slider to move in the vertical direction as the disc rotates, thereby also moving the sword-like saw in the vertical direction. A tool such as a screwdriver is required to rotate the disk, and the tool can be engaged with the corresponding slit of the disk to steadily rotate the disk. Since the windowed cover plate only releases the small angular portion where the slits are located, the adjustment process for the desired chain tightening is significantly troublesome. The cover plate is then fastened to the disc, the sword-like saw and the casing by means of two nuts screwed onto bolts fixed to the casing for the maintenance of the adjusting element. Against this, tools,
In other words, you need a spanner.

[0003]

SUMMARY OF THE INVENTION The present invention provides a simple way of adjusting the sword-like saw and the reliable tightening of the adjusting element in the absence of the respective tools. The object is to construct a clamping device of the type mentioned at the beginning.

[0004]

The above object is achieved by a structure characterized in that the guide groove extends over an angle of rotation of at least 270 °.

[0005]

The essential advantage of the present invention is that the slight inclination of the guide groove enables easy manual operation and precise adjustment, and the sword-like saw portion can be easily adjusted. All the forces acting in the longitudinal direction are absorbed by the disc, with no force acting on the disc in the rotational direction. The tangent to the guide groove at the point where the pins are joined is a line perpendicular to the longitudinal direction of the sword-shaped saw, and the force acts in the direction of rotation on the disk because it lies in the friction cone where this line intersects. do not do. The forces generated thereby are absorbed very advantageously.

It is a particularly effective construction of the fastening device according to the invention that the guide groove extends over a rotation angle of a magnitude between 360 ° and 450 °. With such a large rotation angle, the inclination of the guide groove is kept very small. This solution is then regarded as optimal for reasons of construction and for manipulability by hand. The difference between the minimum distance and the maximum distance from the center of rotation of the disc to the guide groove determines the maximum movement distance of the sword-like saw. This difference is
Especially it should be about 20 mm.

The disk is provided with a recess or depression on its outer circumference so that the disk is easy to handle and can be easily rotated in the loosened state of the mounting device. When the attachment device is loosened for various reasons, a force acting as a rotational moment on the sword-shaped saw portion may be generated in the sword-shaped saw portion. In order to block this rotational moment, a guide element is formed in the casing, which engages with the slit of the sword-like saw.
The guide element can be elongated or rounded.

In an advantageous configuration of the slider, the slider is substantially U-shaped and the pins which function with the guide grooves are located in the U-shaped bend and are respectively near the ends of the U-shaped legs. A protrusion directed away from the pin is arranged to engage a corresponding opening in the sword-like saw. Alternatively, the slider can also have the form of a flat plate. This plate has a pin for a guide groove on one side surface and a protrusion for engaging a sword-like saw on the other side surface, and the pin and the protrusion are substantially the same with respect to at least the slider surface. The structure is located on the orthogonal line.

It is proposed to provide as a clamping element a hinge nut that can be screwed onto a bolt fixed to the casing, so that the clamping device can be operated entirely by hand without tools. In order to easily obtain the required tightening force by hand tightening the butterfly nut,
Its size is decided. The clamping element can likewise comprise a knurled wheel or a wheel with corrugated edges, which can be screwed onto a threaded bolt fixed to the casing. An anti-rotation pressure plate is arranged between the clamping element and the disc.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are explained in more detail below with reference to the drawing.

FIG. 1 shows an exploded perspective view of a casing 10 of a power chain saw, namely the area in which there is an opening 11 for the drive pinion and a holding device for the sword-like saw 12, which is not shown. The holding device comprises a threaded bolt 13 and a guide pin 14 fixed to the casing. The threaded bolt 13 then projects through the sword-shaped saw 12, the rotatable disc 16 and the pressure plate 17 in the region of the longitudinal opening 15 and the end of the thread is screwed by a manual handle 18. It is high enough to be fastened. The guide pin 14 engages in the longitudinal opening 15 of the sword-like saw, whereby the sword-like saw 1
Two precision longitudinal guides as well as dimensions are provided to aid in the absorption of rotational moment forces.

Next to the vertically elongated opening 15 of the sword-shaped saw 12, there are two openings 19 in the shape of small holes. The openings 19 are beside the ends of the legs 20 of the U-shaped slider 8. The protrusions 21 arranged at are accurately fitted and engaged.
The U-shaped slider 8 is provided with a pin 9 on the curved portion 22 that protrudes from the slider surface on the side opposite to the sword-shaped saw portion 12. This pin 9 engages in the curved guide groove 5 of the rotatable disc 16. Guide groove 5 is almost 3
It extends over a rotation angle of 90 °. At that time, the end 6 of the guide groove 5 has the minimum distance to the rotation center point D, and the other end 7
Has the highest distance. By rotating the disk 16,
Due to the pin 9 engaging in the guide groove 5, the rotational movement is replaced by the vertical movement of the slider 8, which in turn causes an equal amount of movement of the sword-like saw 12. The total possible travel distance depends on the difference between the minimum distance and the maximum distance from the center of rotation.

The rotatable disc 16 has indentations 23 regularly arranged on its edge, which guarantee good manual maneuverability in adjusting the tension of the chain. In order to attach the disc 16 to the bolt 13, the disc 16
Has a central hole 24. A pressure plate 17 and a manual handle 18 are provided in order to preserve the adjusted chain tightening. The pressure plate 17 has a hole 25 through which the threaded bolt 13 penetrates and also has a protrusion 26 directed towards the casing 10.
6 engage with corresponding openings 27 in the casing and thus hold the pressure plate, ie the chain gear cover 17, against rotation. The pressure plate 17 is pressed against the disc 16 by means of a manual handle 18 which can be screwed onto the threaded bolt 13, thereby eliminating undesired movement of the disc 16 due to vibrations or the like. In order to enhance the frictional coupling between the members, the slider 8
It is advantageous that the surface of the disk 16 facing the side of the disk 16 and the surface of the slider 8 facing the side of the disk 16 are provided with notches such as a cross shape. This prevents the disc 16 from rotating at the same time when the manual handle 18 is tightened. The manual handle 18 is provided with corrugated edges 28 so that sufficient force can be applied to the manual handle 18 without tools.

The tightening device shown in FIGS. 2 to 4 is
It is based on the same principle as the tightening device shown in FIG.
In this case, a slider of another shape is used which increases the pressing force between the disk and the sword-shaped saw portion or the pressing force between the casing and the sword-shaped saw portion. FIG. 2 shows a partial cross-sectional view of the casing 1 made of synthetic resin, for example.
A threaded bolt 13 is fixed to the casing 1, and the threaded bolt 13 projects through the vertically long opening 15 of the sword-shaped saw portion 12, the slider 2, and the rotatable disk 3. The casing 1 has a long guide element 29 that engages with the vertically long opening 15 of the sword-like saw portion 12.
Are formed. The slider 2 has a flat plate shape, and a pin 9 protruding into the guide groove 4 of the disk 3 is formed on the surface of the plate 3 on the disk 3 side.
On the other side of the slider 2, there is a sword-like saw 12
There is a protrusion 30 that engages with the vertically long opening 15 and is located on the same orthogonal line as the pin 9 with respect to the plane of the slider 2.

The shape of the slider 2 is clear from FIG. The shape of the slider 2 here is a substantially rectangular plate having a vertically long slit 31 oriented in the same direction as the vertically long opening 15 of the sword-shaped saw portion 12. Pin 9
Project into a guide groove 4 which spirally extends around a central hole through which the threaded bolt 13 penetrates. Guide groove 4
The overall rotation angle of is about 450 ° in FIG. If the rotation angle is only 360 °, the function is the same, but the inclination is slightly different. When the disk 3 rotates clockwise, the pin 9 moves rightward together with the slider 2 through the path of the guide groove 4, whereby the protrusion 30 of the slider 2 moves rightward along the sword-shaped saw portion. Move
Therefore tighten the chain (not shown).

In order to maintain the disc 3 in an adjusted position, a swivel nut 32 screwed onto the threaded bolt 13 and having a pressing plane 33 for making a large face contact with the disc 3 is used. A synthetic resin hood 34, which extends substantially over the bow nut surface, covers the upper part of the sword-shaped saw and the chain that moves there. As shown in FIG. 4, the synthetic resin hood 34 has an opening 35, which allows the hinge nut 32 to be removed without removing the synthetic resin hood.
I have a hand.

The embodiment of the present invention is as follows.

(1) The guide grooves (4, 5) are 360 °
2. The tightening device according to claim 1, extending over an angle of rotation of between .degree.

(2) The difference between the minimum distance and the maximum distance from the rotation center point (D) of the disk (3, 16) to the guide groove (4, 5) is about 20 mm, or the first or the second. 1
The tightening device described in paragraph.

(3) The disk (16) has a recess or a depression (23) on its outer circumference.
The tightening device according to any one of the items 1 and 2.

(4) A casing (1) is provided with a guide element (29) which engages with a vertically elongated opening (15) of a sword-like saw (12). The tightening device according to any one of item 3.

(5) The slider (8) is substantially U-shaped, in which case the U-shaped curved portion (22) has a pin (9) which functions together with the guide groove (5), and U
Near the end of the leg of leg (20), the projection (21) facing away from the pin (9) engages the corresponding opening (19) of the sword-like saw (12). The tightening device according to claim 1 or any one of claims 1 to 4, which is arranged in the.

(6) The slider (2) has the shape of a flat plate, has a pin (9) for the guide groove (4) on one side, and a sword-like saw on the other side. A projection (30) for engaging a portion (12), wherein the pin (9) and the projection (30) are at least on substantially the same orthogonal line to the slider surface. The tightening device according to any one of items 1 to 4.

(7) A fastening nut (32) which can be screwed to a bolt (13) fixed to a casing is provided as a fastening element, and the fastening element is any one of the first to sixth aspects. The tightening device described in one.

(8) The tightening element is screwable to the threaded bolt (13) fixed to the casing,
7. Clamping device according to claim 1 or any one of claims 1 to 6, which is a handwheel (18) having a knurled wheel or a corrugated edge (28).

(9) A pressure plate which is prevented from rotating, in particular a chain gear cover (17), is arranged between the tightening element (18) and the disc (16). Tightening device.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of a tightening device.

FIG. 2 is a horizontal sectional view of a second embodiment of the tightening device.

3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a view seen in the direction of arrow IV in FIG.

[Explanation of symbols]

 1 Casing 2 Slider 3 Disk 4 Guide groove 5 Guide groove 8 Slider 9 Pin 10 Casing 12 Sword-like saw part 16 Disk 18 Tightening element 32 Tightening element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hans Nickel Germany Day 7153 Kotten Weiler Lörchenstraße 6 (72) Inventor Helmut Zimmermann Germany Day 7053 Kernen im Remster Jaegerstraße 8

Claims (1)

[Claims] 1. A casing (1, 10) in which a sword-like saw (12) receives a drive engine and a fastening element (1).
(8, 32) and the ends are clamped and held,
Moreover, when the tightening elements (18, 32) are loosened, the sword-like saw part (12) is movable in the longitudinal direction,
For this movement, the slider (2, 8) having the pin (9) protruding laterally with respect to the movement direction and the pin (9)
And a rotatable disc (3, 16) having curved guide grooves (4, 5) engaging with each other, for a chain moving a sword-like saw (12) of a power chainsaw Fastening device, characterized in that the guide grooves (4, 5) extend over an angle of rotation of at least 270 °.