JPH1142017A - Chain saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chain saw capable of smoothly cutting objects through keeping the cutting edge angle constant even with a looseness in the chain saw somewhat. SOLUTION: This chain saw is so designed that, one side of both ends of a steel piece is provided with a recessed connective part 16, respective guide members 15 each provided with a plurality of serrated cutting edges 17 at intervals each equivalent to at least one edge width ranging from the front end through the rear end as a whole along the upper edge are mutually linked in a flexible way via rivets 18 to construct the chain saw 14, and furthermore, the projections of both ends of each of the rivets defines a pair of chain feed guide 19; whereas, the chain saw 14 is extendedly set up on several points around a disk fixed on the rotational axis of the chain saw and having a groove inside, a sprocket provided with virtually semicircular recesses at respective points against the above points and a chain guide bar having a guide groove along the outer circumference, and the chain feed guide 19 and the recesses of the sprocket are engaged with each other so as to set the chain saw in motion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chain saw and a sprocket used for a chain saw.

[0002]

2. Description of the Related Art A conventional chain saw 14 shown in FIG. 6 has a plurality of sawtooth-shaped cutting blades 17 formed on an upper edge thereof and a guide member 15 having a lower edge formed as a chain feed guide plate B.
Are arranged, and a link plate A and a rivet 18 are arranged.
And the like.

The sprocket for driving the chain saw is a cylindrical sprocket having a peak H and a valley P as shown in FIG. 6A, and the lower side of the link plate A and the sprocket of the sprocket are in contact with each other. The lower edge B of the guide member is engaged with the valley C.

[0004]

As already known, in order for the chain to run smoothly, it is necessary that there is a suitable gap between the chain and the chain guide bar, that is, the chain has some looseness. is there. Looseness also occurs due to wear during use. In the conventional chain saw, since the guide members 15 are connected to the link plate A via the rivets 18, the guide members 15 having the cutting blades are individually operated when the chain is loose. When the chain is driven and the cutting blade cuts into the workpiece K, as shown in FIG. 7, the link load is applied by the cutting load applied to the first cutting blade 17 of the guide member 15. Since the guide member 15 is also inclined together with the point A and the front end rises, and the cutting blade 17 has a deep cutting angle,
The cutting resistance increases. Since this state occurs repeatedly during the cutting, there is a disadvantage that the smooth execution of the cutting operation is hindered.

The present invention has been made in view of the above-mentioned problems, and has as its object to provide a chain saw that does not hinder the cutting performance at all even if the chain saw is slightly loosened.

[0006]

According to the present invention, a chain saw is provided on one side of a front end of a guide member which is a component thereof.
A concave connecting portion is provided, and a concave connecting portion is provided at the rear end on one side opposite to the former, so that the two concave portions can be fitted. Each of the guide members is provided with a plurality of saw blades formed on the upper edge from the blade-attached position to the rear end of the guide member by cutting the cutting blades at intervals corresponding to at least one blade width. , Which are connected to bend via rivets.

Further, a pair of chain feed guides is constituted by projections on both side surfaces of the guide member connecting portion.

Further, a sprocket is constituted by providing a pair of substantially semicircular concave portions at a plurality of locations around a disk having a groove therein.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a chain saw and a sprocket of a chain saw driven by a pulling-down force of an operating rope, and a plurality of cuttings shown in FIG. When the chain is loosened at the transition from the guide member 15a having the blade to the next guide member 15, the cutting load applied to the first cutting blade 17 causes the front end of the guide member 15 to incline and float, and the cutting blade 17 As described above, the incision tends to be inclined at an angle at which the incision becomes deep. However, in the case of the present invention, the guide members are fitted and connected to each other, and the cutting blade 17a is located adjacent to the cutting blade 17 and straddles the front end of the guide member 15. In most cases, since the diameter of the work material is larger than the gap between the two cutting blades, the cutting of the cutting blade 17a has not been completed yet, and is located at a position farthest from the rivet 18, which is a fulcrum shaft. Therefore, there is escape to the side having no resistance due to the cutting resistance. Since the direction of the escape opposes the rising of the front end of the guide member 15, the inclination of the cutting blade 17 is suppressed. In this manner, each cutting is repeated while maintaining a uniform cutting depth.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a base for attachment to the tip of a rod, and reference numeral 2 denotes a receiving shaft fixed to one side surface of a substrate 3. A claw gear 7 is rotatably supported by the receiving shaft 2 together with a drive arm 6 having a pulley 5 to which an operation rope 4 is added at the tip. One end is attached to the substrate 3 and the other end is attached to the tip of the drive arm 6, respectively, via a return spring 8 for returning the drive arm 6 to its original position, and a claw 9 attached to the drive arm 6. The driving arm 6 and the pawl gear 7 are engaged with each other, and the spur gear 10 meshing with the pawl gear 7 is connected to the spur gear 1 via a rotating shaft 11 penetrating the substrate 3.
A sprocket 12 is connected to the sprocket 12 on one side of the substrate 3 on the opposite side of the sprocket 12, and a chain saw bar is mounted on the sprocket 12 and the chain guide bar 13 fixed to the substrate 3 adjacent to the sprocket 12.

FIG. 2 is a perspective view showing details of the chain saw.
FIG. 3 is a sectional view taken along the line AA of FIG. In the figure, a concave connecting portion 16 is provided on one side of the front end of the guide member 15.
At the rear end, a concave connecting portion 16a is provided on at least one side, and a serrated shape is provided at a distance corresponding to at least one blade width of the cutting blade from the front end of the guide member 15. A plurality of cutting blades 17 which are alternately swung left and right are formed on the upper edge reaching the rear end of the guide member 15, and the connecting portions 16 and 16a of the respective guide members 15 are fitted. They are arranged so as to fit together and are foldably connected via rivets 18. FIG. 3 shows A in FIG.
FIG. 3 is a cross-sectional view taken along a line −A, in which a pair of chain feed guides 19 is formed by a fitting connection portion and projections at both ends of a rivet 18 penetrating the connection portion.

FIG. 4 shows a state in which a chain saw is stretched over the sprocket 12 and the chain guide bar B. FIG.
FIG. 3 is a cross-sectional view taken along line BB of FIG. Sprocket 12
Has a substantially semicircular concave portion formed at a plurality of opposing positions around a disk 20 having a groove 20 therein.
1 is fixed.

The chain guide bar 13 has an arc-shaped flat end, and when the chain is driven inside, a guide groove (not shown) for guiding the guide member 15 is provided, and the chain 3 is formed on the substrate 3. Is installed so that the slack is adjustable.

Next, the operation of the chain saw constructed as described above will be described. When the operating rope 4 is pulled down from the ground to hit the upper part of the tall branch where the chain saw is to be cut, the pulling force of the rope by the pulley 5 on which the rope is pulled is increased, and the driving arm 6 is turned. Let it. The pawl 9 mounted on the drive arm 6 is always hooked on the pawl gear 7 to rotate the pawl gear in one direction. Since the pawl gear 7 has a larger number of teeth than the meshing spur gear 10, the rotation of the spur gear 10 is accelerated and
The traveling speed of the sprocket 12 connected to the spur gear via 1 and the chain saw driven by the sprocket increases. When the rope is loosened, the drive arm 6 is returned to the original position at once by the return spring 8.

[0015]

By arranging the cutting blade over the connecting portion of the guide member in the chain saw, it is possible to suppress the inclination of the cutting blade caused by the joint between the guide members due to the load at the time of cutting. The cutting resistance can be prevented, and a chain drive that can be manually driven has been made possible.Moreover, by means of chain connection, the structure of the chain saw can be made much thinner, and cutting performance has been improved. The sprocket according to the present invention also has an effect that a thin chain saw can be driven in a stable state.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a chain in which a back surface is omitted.

FIG. 2 is a perspective view of a chain saw according to the embodiment.

FIG. 3 is a sectional view taken on line AA of FIG. 2;

FIG. 4 is a front view in which a chain saw is stretched over a sprocket and a chain guide bar.

FIG. 5 is a front view taken along line BB of FIG. 4;

FIG. 6 is a perspective view of a conventional chain saw.

FIG. 7 is a front view showing a cut into a work material by the chain saw of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Rotation shaft 12 Sprocket 14 Chain saw 15 Guide member 16 Connecting part 17 Cutting blade 18 Rivet 19 Chain feed guide 20 Groove 21 Disk 22 Recess

Claims (3)

[Claims] 1. A receiving shaft 2 is fixed to a base plate 3 attached to the tip of a rod, and a pawl gear 7 is mounted on the receiving shaft together with a driving arm 6 to which a pulley 5 having an operating rope 4 is attached. 2, the driving arm 6 is engaged with the pawl gear 7 via the pawl 9, the spur gear 10 meshes with the pawl gear, and the spur gear and the sprocket are connected via the rotating shaft 11. A chain connecting bar 16 attached to the base plate 3 and a chain saw with a chain saw 14 stretched over a sprocket are provided with a concave connecting portion 16 on one side of a front end of a guide member 15 and at least one side on a rear end thereof. And a serrated cutting blade 17 is provided at a distance from the front end of the guide member 15 corresponding to at least one blade width of the cutting blade. A plurality of cutting blades 17 are formed on the upper edge reaching the rear end of the guide member 15. A chain saw, wherein the connecting portions 16 and 16a are fitted and arranged, and are connected to bendable via rivets 18 to form a chain saw. 2. The chain according to claim 1, wherein a pair of chain feed guides is formed by projections at both ends of the rivet connecting the guide portions. 3. A sprocket 12 according to claim 1, wherein a pair of substantially semicircular recesses 22 are provided at a plurality of locations around a disk 21 having a groove 20 therein.