Connecting link for a saw chain

Abstract

A connecting link (4, 34) for a saw chain (1) of a motor-driven chain saw has an areal base body (24) which has two rivet openings (12, 15). The connecting link (4, 34, 44) has a longitudinal center axis (11) which intersects the axes (13, 16) of rivet openings (12, 15) and runs in the base body (24). The functional regions of the connecting links (4, 34, 44) are mirror symmetrical to planes (32, 36), which contain the longitudinal center axis (11), and are unsymmetrical to each plane perpendicular to the longitudinal center axis (11). In this way, the connecting link (4, 34, 44) can be arranged on both longitudinal sides of the saw chain (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawings wherein:

FIG. 1 is a side elevation view of a saw chain;

FIG. 2 is a side elevation view of a connecting link of a saw chain;

FIG. 3 is a schematic section view of the connecting link of FIG. 2 along the line III-III in FIG. 2;

FIG. 4 is a schematic section view taken along line IV-IV in FIG. 2;

FIG. 5 is a schematic section view taken along line III-III of FIG. 2 and shows an embodiment of a connecting link;

FIG. 6 is a schematic section view taken along line IV-IV of FIG. 2 for an embodiment of a connecting link;

FIG. 7 is a side elevation view of an embodiment of a connecting link;

FIG. 8 is a partially cut perspective view of the connecting link of FIG. 7;

FIG. 9 is an embodiment of a connecting link shown in a side elevation view;

FIG. 10 is a section view taken along line X-X of FIG. 9; and,

FIG. 11 is a partial section perspective view of the connecting link of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

A portion of a saw chain 1 is shown in FIG. 1 and the saw chain is assembled of drive links 2, cutting links 3 and connecting links 4. The drive links 2, cutting links 3 and connecting links 4 are articulately connected to each other via rivet bolts 6. The drive links 2 are arranged in the center and connecting links 4 are provided at the outer sides of the drive links. The trailing rivet opening of a drive link 2 is connected to a forward rivet opening of a connecting link 4 and a forward rivet opening of a drive link 2 is connected to a rearward rivet opening of a connecting link 4. Viewed in a saw chain running direction 5, a cutting link 3 is arranged in lieu of a connecting link 4 every two connecting links 4. The cutting links 3 are provided alternately on respective longitudinal sides of the saw chain 1. The cutting links 3 have a cutting tooth 7 with a depth limiter 8 arranged forward thereof. A support protuberance 9 for reinforcing the depth limiter can be provided on a neighboring drive link 2 next to the depth limiter 8. The drive links 2 have a lubricating channel 10 which is connected to the openings of the rivet bolts 6 and via which the lubricating oil is conveyed to the rivet openings.

In FIG. 2, an enlarged connecting link 4 is shown. Referred to the running direction 5 of saw chain, the connecting link 4 has a leading rivet opening 12 having an axis 13 as well as a trailing rivet opening 15 having an axis 16. The connecting link 4 has an areal base body 24 wherein a longitudinal center axis 11 of the connecting link 4 lies. The longitudinal center axis 11 intersects the axes 13 and 16 of the rivet openings 12 and 15. The connecting link 4 has a middle region 23 between the two rivet openings (12, 15) wherein an impression 20 is arranged. The impression 20 is configured as a triangle with rounded corners and forms an arrow head which points in the running direction 5 of the saw chain.

As shown in FIG. 4, the impression 20 has a depth t₁ which corresponds to between 5% to 25% of a width b₄ of the base body 24 of the connecting link 4. The depth t₁ and the width b₄ are measured parallel to the axes 13 and 16 of rivet openings 12 and 15, respectively. The connecting link 4 has a plane 32 which contains the longitudinal center axis 11 and the axes 13 and 16 of rivet openings 12 and 15, respectively. The plane 32 intersects the impression 20 at the middle so that sections of the impression 20, which are arranged above and below the plane 32, are symmetrical to the plane 32. The impression 20 can, however, also be arranged or configured to be unsymmetrical to the plane 32.

The connecting link 4 has a forward running surface 21 having a length L₁ next to the leading rivet opening 12. The running surface 21 runs parallel to the longitudinal center axis 11 and to the plane 32 and, during operation, lies on a guide bar of a motor-driven chain saw. A rearward running surface 22 is provided next to the trailing rivet opening 15 and this rearward running surface 22 has a length L₂. The length L₂ of the rearward running surface 22 is longer than the length L₁of the forward running surface 21. The length L₂ of the rearward running surface can, advantageously, be 1.2 times to 2 times the length L₁ of the forward running surface 21. The rearward running surface 22 is inclined at an angle α relative to the forward running surface 21. The angle α opens opposite to the running direction 5 and can be 1° to 5° and especially 2° to 3°.

In the region of the forward running surface 21 and the leading rivet opening 12, the connecting link 4 has an elevation h₁, which is measured perpendicularly to the plane 32, and this elevation h₁ is greater than the maximum elevation h₂ of the connecting link 4 in the region of the rearward running surface 22. Because of the inclination of the rearward running surface 22, the elevation h₂ is measured in the forward region of the rearward running surface 22 whereat the maximum extent of the connecting link 4 lies perpendicularly to the plane 32. The center region 23 has an elevation h₃, which is measured perpendicularly to the plane 32, and this elevation h₃ is less than the elevation h₁ and the elevation h₂. The connecting link 4 has a constriction in the center region 23 whereat the impression 20 is arranged. Also, a distance c₁ between the longitudinal center axis 11 and the forward running surface 21 is greater than a distance c₂ between the longitudinal center axis 11 and the rearward running surface 22. The distance c₂ identifies the maximum distance between the longitudinal center axis 11 and the rearward running surface 22 perpendicular to the plane 32.

On the forward high end 30 referred to the running direction 5, the connecting link 4 has an edge 18 which is configured to be even and extends perpendicularly to the longitudinal center axis 11 and to the plane 32. On the rearward high end 31 referred to the running direction 5 of the saw chain, the connecting link 4 has a likewise even rearward edge 19 configured perpendicularly to the longitudinal center axis 11. Concave radii (r) extend at both ends from the two edges (18, 19). The forward high end 30 and the rearward high end 31 run arcuately in the region lying outside of the linear edges (18, 19) so that rounded high ends 30 and 31 result. The arcuate high ends (30, 31) are connected to edges (18, 19) via the concave radii (r).

As shown in FIG. 3, the rivet opening 12 has a countersink 28 on its outer side 26 which faces outwardly during assembly on a saw chain 1. The countersink 28 has a width b₁. The width b₁ is measured parallel to the axis 13 of the rivet opening 12. On the opposite-lying inner side 27, the rivet opening 12 has a bevel 29 having a width b₂. The width b₂ of the bevel 29 is considerably smaller than the width b₁ of the countersink 28. The width b₁ of the countersink 28 can, for example, amount to 1.5 to 8 times the width b₂. Advantageously, the width b₁ is more than 3 times the width b₂.

As shown in FIG. 2, the connecting link 4 is configured to be mirror symmetrical to the plane 32. The upper end 25, which faces away from the running surfaces 21 and 22, likewise has a contour with running surfaces and a constriction between the running surfaces. The trailing rivet opening 15 of the connecting link 4 has a countersink 33 which corresponds to the countersink 28 of the leading rivet opening 12. A bevel (not shown) is also provided on the opposite-lying inner side 27 at the trailing rivet opening 15.

In FIG. 5, a section through an embodiment of a connecting link 4 is shown. The rivet opening 12 has respective bevels 14 on the outer side 26 and on the inner side 27. The two bevels 14 have identical widths b₃ measured parallel to the axis 13 of the rivet opening 12. The rivet opening 12 with the two bevels 14 is configured mirror symmetrical to the plane 36. The trailing rivet opening 15 is configured identically. In this way, the functional regions of the connecting link 4, namely, the rivet openings, the bevels at the rivet openings as well as the running surfaces of the connecting link 4 are configured mirror symmetrically to the plane 32 as well as to the plane 36. The connecting link 4 can be arranged with the outer side 26 as well as with the inner side 27 on a drive link 2. The inner side 27 and the outer side 26 are configured identically.

As shown in FIG. 6, an impression 20 can be provided on the outer side 26 as well as on the inner side 27. The impressions 20 can also be configured to be symmetrical to the plane 36 and to the plane 32. The impressions 20 have respective depths t₂, which are measured perpendicularly to the plane 36, and which advantageously amount to between 5% and 25% of a width b₄ of the base body 24 of the connecting link 4. The impressions 20 are shown as recesses. For this reason, they define no functional region of the connecting link 4 and can therefore also be configured and arranged unsymmetrically to the plane 36 and/or plane 32.

A further embodiment of a connecting link 34 is shown in FIG. 7. The configuration of the connecting link 34 corresponds essentially to the configuration of the connecting link 4 from FIGS. 1 to 4. The same reference numerals are used for the same elements. The connecting link 34 differs from the connecting link 4 from FIGS. 2 to 4 by the configuration of the rivet openings (12, 15). As also shown in FIG. 8, the leading rivet opening 12 has respective bevels 14 on the outer side 26 and the inner side 27. The bevels 14 have a width b₃ which is the same size on the outer side 26 and the inner side 27. The trailing rivet opening 15 has corresponding bevels 17 which have the same width on the outer side 26 and the inner side 27. The configuration of the rivet openings 12 and 15 of the connecting link 34 thereby corresponds to the configuration of the rivet openings of the connecting link 4 in the embodiment shown in FIGS. 5 and 6.

As shown in FIG. 7, the upper end 35 of the connecting link 34 is configured to be even. The upper end 35 lies facing away from the running surfaces 21 and 22. The upper end 35 runs parallel to the longitudinal axis 11 and to the plane 32 (not shown in FIG. 7) which is defined by the longitudinal center axis 11 and the axes 13 and 16 of the rivet openings 12 and 15, respectively. The connecting link 34 has an elevation h₄ in the region of the leading rivet opening 12. This elevation h₄ is greater than the elevation h₅ in the region of the trailing rivet opening 15. The center region 23 has an elevation h₆ which is less than the elevation h₄ and less than the elevation h₅. The distance c₁ between the longitudinal center axis 11 and the forward running surface 21 is greater than the distance c₂ between the rearward running surface 22 and the longitudinal center axis 11. The distances (c₁, c₂) correspond to the distances (c₁, c₂) for the connecting link 4. All elevations (h₄, h₅, h₆) and the distances c₁ and c₂ are measured perpendicularly to the plane 32.

The connecting link 34 is configured to be mirror symmetrical to a plane 36 which contains the longitudinal center axis 11. The longitudinal center axis 11 runs perpendicularly to the axes 13 and 16 of the rivet openings 12 and 15 and this longitudinal center axis 11 runs in the plane of the base body 24. The connecting link 34 can be arranged on both sides of the saw chain 1 because of the symmetrical configuration. The head of a rivet bolt, which is arranged in the rivet openings 12 and 15, lies once on the outer side 26 and, for an arrangement on the opposite-lying side of the saw chain 1, lies on the inner side 27 which, in this case, is directed outwardly.

A further embodiment of a connecting link 44 is shown in FIGS. 9 to 11. The connecting link 44 corresponds essentially to the connecting link 34. The same reference numerals identify like elements of the connecting link. On its upper end 35, the connecting link 44 has a bevel 45 which extends over the entire length of the upper end 35. As shown in FIG. 10, the bevel 45 is arranged on the outer side 26 of the connecting link 44. The connecting link 44 has an impression 20 on the outer side 26 as well as on the inner side 27. The impression 20 has a depth t₂ which corresponds to the depth t₂ of the connecting link 4 of FIG. 6. Both impressions 20 are arranged symmetrically to the plane 36. The impressions 20 are configured as arrows and both point in the same direction, namely, they point in running direction 5. However, an unsymmetrical arrangement and configuration can be provided because the impressions 20 form no functional regions of the connecting link 44. The bevel 45 also defines no functional region of the connecting link 44; instead, the bevel 45 functions as a marking for the sorting and for the orientation of the connecting link 44.

As FIG. 11 shows, the rivet openings 12 and 15 of the connecting link 44 have respective bevels 14 and 17 whose widths b₃ are identical on the outer side 26 and the inner side 27 of the connecting link 44. The rivet openings 12 and 15 with the bevels 14 and 17 are configured symmetrically to the plane 36 of the connecting link 44 shown in FIG. 10. The running surfaces 21 and 22, which likewise define functional regions, extend over the entire width of the connecting link 44 measured perpendicularly to the plane 36 so that the running surfaces 21 and 22 are also configured symmetrically to plane 36. The functional regions of the connecting link 44 are configured symmetrically to the plane 36. For this reason, the connecting link 44 can be arranged on both longitudinal sides of the saw chain 1. In the arrangement on the right side of the saw chain 1 viewed from the running direction 5, the outer side 26 lies outside and the inner side 27 lies inside next to a drive link 2. In the arrangement on the left longitudinal side of the saw chain 1 seen in the running direction 5, the outer side 26 lies inside and the inner side 27 of the connecting link 44 is directed outwardly. Because the impressions 20 and the bevels 45 are configured as recesses of the base body 24 and do not project beyond the plane of the base body 24, the configuration and arrangement of the impressions 20 and of the bevels 45 are irrelevant for the arrangement of the connecting link 44 on a saw chain 1. An impression 20 is arranged on each side (26, 27). For this reason, it is visible to the operator whether the connecting link 44 is assembled in the correct orientation on the saw chain. It can also be provided that a connecting link 44 has only one bevel 45 or another recess on the base body 24 which is visible from the outside and that no impression 20 is provided in the base body 24 of the connecting link. 44.

It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A connecting link for a saw chain of a motor-driven chain saw, the connecting link comprising: a flat base body having first and second rivet openings defining first and second rivet opening axes;said flat base body defining a longitudinal middle axis running through said flat base body and intersecting said first and second rivet opening axes;said longitudinal middle axis and said first and second rivet opening axes conjointly defining a plane; and, said flat base body having functional regions mirror symmetrical to said plane.

2. The connecting link of claim 1, wherein said flat base body has an outer side and an inner side; each of said rivet openings has first and second bevels on said outer and inner sides, respectively; and, said first and second bevels have the same width (b3) measured parallel to the corresponding rivet opening axis.

3. The connecting link of claim 1, wherein said plane is a first plane; and, said connecting link is configured to be mirror symmetrical with respect to a second plane perpendicular to said first and second rivet opening axes.

4. The connecting link of claim 1, wherein said plane is a first plane; and, said connecting link is configured to be mirror symmetrical with respect to a second plane containing said longitudinal middle axis and said first and second rivet opening axes.

5. The connecting link of claim 4, wherein said base body has an outer side and an inner side; each of said rivet openings has a countersink at said outer side and a bevel at said inner side; said countersink has a first width (b1) measured parallel to the corresponding rivet opening axis; said bevel has a second width (b2); and, said first width (b1) is greater than said second width (b2).

6. The connecting link of claim 1, wherein said saw chain runs in a predetermined running direction and said first rivet opening lies forward of said second rivet opening viewed in said running direction; said connecting link has a first elevation in the region of said first rivet opening measured perpendicularly to said first rivet opening axis and said longitudinal middle axis; said connecting link has a second elevation in the region of said second rivet opening measured perpendicularly to said second rivet opening axis and said longitudinal middle axis; and, said first elevation is less than said second elevation.

7. The connecting link of claim 1, wherein said saw chain runs in a predetermined running direction and said first rivet opening lies forward of said second rivet opening viewed in said running direction; said connecting link has a first elevation in the region of said first rivet opening measured perpendicularly to said first rivet opening axis and said longitudinal middle axis; said connecting link has a second elevation in the region of said second rivet opening measured perpendicularly to said second rivet opening axis and said longitudinal middle axis; said base body has a region disposed between said rivet openings; and, said flat base body has an elevation at said region which is less than said first elevation and less than said second elevation.

8. The connecting link of claim 1, wherein said saw chain runs in a predetermined running direction and said first rivet opening lies forward of said second rivet opening viewed in said running direction; said connecting link has a forward running surface adjacent said first rivet opening and a rearward running surface adjacent said second rivet opening; said forward and rearward running surfaces have first and second lengths, respectively; and, said second length is longer than said first length.

9. The connecting link of claim 8, wherein said forward running surface extends parallel to said longitudinal middle axis.

10. The connecting link of claim 8, wherein said forward running surface and said rearward running surface conjointly define an angle (α).

11. The connecting link of claim 10, wherein said angle (α) opens rearwardly referred to said predetermined running direction.

12. The connecting link of claim 10, wherein said angle (α) lies in a range from 1° to 5°.

13. The connecting link of claim 8, wherein said forward running surface has a maximum distance (c1) to said longitudinal middle axis and said second running surface has a maximum distance (c2) to said longitudinal middle axis: and, said maximum distance (c1) of said forward running surface is greater than said maximum distance (c2) of said rearward running surface.

14. The connecting link of claim 8, wherein said flat base body has a top end facing away from said forward and rearward running surfaces; and, said top end extends evenly.

15. The connecting link of claim 14, wherein said top end extends parallel to said longitudinal middle axis.

16. The connecting link of claim 1, wherein said flat base body has a depression formed therein.

17. The connecting link of claim 16, wherein said depression is disposed between said first and second rivet openings and is configured as an impression and material of said flat base body is compressed in the region of said impression.

18. The connecting link of claim 17, wherein said impression is intersected by said plane.

19. The connecting link of claim 17, wherein said saw chain runs in a predetermined running direction; and, said impression has the form of an arrowhead which points in said predetermined running direction.

20. The connecting link of claim 19, wherein said flat base body has said first and second sides and said impression is a first impression formed in said first side and said flat base body has a second impression formed in said second side; and, said first and second impressions both point in the same direction.

21. The connecting link of claim 16, wherein said depression is configured as a bevel.