Connecting link and saw chain with a connecting link

Abstract

The invention relates to a connecting link (10) for a saw chain (8) of a motor-driven work tool (1), having two rivet openings (13, 14). At least one of the rivet openings (13, 14) has a first portion (22) and a second portion (23), wherein the first portion (22) is cylindrical and the second portion (23) is designed as a conical portion (29) in at least one circumferential region. The second portion (23) extends to a lateral surface (17). At least in an imaginary plane (55) which contains the centre axis (15, 16) of the rivet opening (13, 14) and extends perpendicularly to the longitudinal centre axis (19), the second portion (23) has, on the side of the rivet opening (13, 14) which is close to the underside (51), a thickened portion (24) in relation to a completely circumferential conical surface. A saw chain (8) comprises a connecting link (10).

Description

[0001] Connecting link and saw chain with a connecting link

[0002] The invention relates to a connecting element of the type specified in the preamble of claim 1 and a saw chain with a connecting element.

[0003] EP 0 304 270 A2 describes a saw chain with a connecting link. To prevent the rivet from twisting in the rivet hole, it is provided that part of the rivet hole is designed asymmetrically around the opening axis or inclined towards the opening axis.

[0004] The invention is based on the objective of creating a connecting link of the generic type that has improved properties. A further objective of the invention is to provide a saw chain with a connecting link having improved properties.

[0005] This problem is solved with respect to the connecting element by a connecting element having the features of claim 1. With respect to the saw chain, the problem is solved by a saw chain having the features of claim 9.

[0006] It has been shown that existing solutions often fail to achieve a sufficiently rotationally rigid connection and / or induce stresses in the connecting link, which can reduce the service life of a saw chain equipped with the connecting link. According to the invention, a thickening is provided in a second section of the rivet opening. The second section is a section that is formed as a conical section in at least one circumferential region. The second section extends to a side surface. The thickening is arranged on the side of the rivet opening in the second section that is closest to the underside. The underside is the side of the connecting link on which at least one running surface runs, the running surface being designed to contact a guide rail.

[0007] It has been shown that very high stresses develop in the connecting link on the side of the rivet hole closest to the underside during operation. By arranging the thickening at least in this area, the resulting stresses can be reduced and the connecting link reinforced in the area where the load is particularly high. By arranging the thickening in the second section, which extends to the side surface, it can be ensured that, during the saw chain manufacturing process, the rivet bolt material is positively engaged with the thickening when the rivet head is formed. High forces act on the rivet bolt near the side surface during the forming of the rivet head, resulting in a high degree of deformation of the rivet bolt material.Thickening in this area can achieve both a reinforcement of the connecting element and a rotationally fixed positive fit between the connecting element and the rivet bolt.

[0008] It has also been shown that, due to the minimal deformation of the rivet pin in the cylindrical first section, thickening in this section does not provide sufficient anti-rotation protection. Thickening in the first section reduces the minimum cross-section of the rivet pin and can therefore decrease the strength and thus the service life of a saw chain designed in this way. These disadvantages are avoided with the solution according to the invention.

[0009] In particular, the second section in the imaginary plane exhibits a further thickening on the side of the rivet hole furthest from the underside, opposite a fully circumferential conical surface. It has been shown that high stresses can also occur on the side of the rivet hole furthest from the underside during the operation of a saw chain equipped with the connecting link. The side of the rivet hole furthest from the underside is the side of the rivet hole closest to the top of the connecting link. On a saw chain, the top of the connecting link is located on the side of the saw chain where the saw teeth are positioned for engagement with a workpiece.

[0010] In particular, the connecting element is a cutting element that has a cutting tooth. The cutting tooth is located on the upper side of the connecting element. The underside of the connecting element is the side of the cutting element furthest from the cutting tooth.

[0011] In particular, a transition angle measured at the interface between the conical section and the thickening is an obtuse angle. The transition angle is measured in a plane parallel to the side surface and to a tangent to the conical section. Specifically, at least one transition angle measured on the side surface is an obtuse angle. In particular, the transition angle in every plane parallel to the side surface through which the thickening extends, including the transition angle measured on the side surface itself, is an obtuse angle.

[0012] It has been shown that a notch effect can occur at the transition between the conical section and the thickening, leading to a weakening of the connecting element in this area. The notch effect in this area can be reduced by using an obtuse transition angle. In particular, the transition angle is at least 110°, and more specifically, at least 120°. To allow for a sufficiently large thickening, it is specifically intended that the transition angle be less than 160°.

[0013] In particular, the second section connects to the first section. Specifically, the rivet opening has only two sections: the first section, which is cylindrical, and the second section, which is conical in at least one circumferential region. A minimum distance of the rivet opening in the second section from the central axis corresponds, in particular, to at least half the diameter of the rivet opening in the first section. This ensures that the thickening of the connecting element does not excessively weaken the rivet bolt.

[0014] The thickening has a width, measured parallel to the central axis of the rivet hole, that is at least 30%, and in particular at least 40%, of the width of the connecting element. In particular, the thickening extends over the entire width of the second section. Alternatively, it may be provided that the thickening extends only over a portion of the width of the second section. In particular, the thickening extends to the side surface. A gap to the side surface may also be provided. This gap is, in particular, comparatively small. A gap to the side surface is, in particular, less than 10% of the width of the connecting element.

[0015] In particular, the thickening defines the rivet hole with a flat surface. This allows the thickening to be easily created using a flattened punch to produce the rivet hole. The flat surface design also easily allows for a sufficiently large transition angle.

[0016] The thickening advantageously extends over a circumferential angle of at least 30°, and in particular at least 40°, around the central axis. This allows a sufficiently strong positive fit between the rivet and the connecting element to be achieved without having to reduce the core diameter of the rivet.

[0017] The thickening extends in particular over a circumferential angle of at most 120°, in particular at most 90°, in particular at most 70°.

[0018] The cone angle of the cone section is, in particular, less than 30°, and especially less than 20°. The cone angle is measured in a section plane containing the central axis of the cone section, relative to the central axis of the rivet hole. In particular, the central axis of the cone section coincides with the central axis of the rivet hole.

[0019] Because the cone angle of the cone cut is relatively small, sufficient anti-rotation protection of the rivet bolt can be ensured.

[0020] The cone angle is particularly greater than 5°, ensuring sufficient deformation of the rivet pin during the production of a riveted joint. This also contributes to the reliable creation of the anti-rotation device.

[0021] In particular, the rivet hole has at least three, and especially at least four, thickenings. If there are multiple thickenings, they are arranged symmetrically around the central axis of the rivet hole. Four thickenings have proven to be particularly advantageous. However, a different number of thickenings may also be advantageous. In particular, an even number of thickenings is provided, with at least one thickening located adjacent to the underside of the connecting element and another adjacent to the top side of the connecting element. An odd number of thickenings may be particularly advantageous if lower stresses occur at the rivet hole adjacent to the top side of the connecting element.

[0022] The running surface of the connecting element, which is arranged on the underside, is in particular a surface which is flat, which has a length which corresponds to at least half the diameter of the rivet opening in the first section and which forms an angle of 0° to 10° with the longitudinal central axis.

[0023] A saw chain has connecting links according to the invention.

[0024] The saw chain features, in particular, connecting links arranged in pairs and drive links arranged between pairs of connecting links, which are articulated to one another via rivets. The connecting links and the drive links are typically offset from each other in the longitudinal direction of the saw chain, such that a front rivet opening of a drive link projects between the rear rivet openings of two connecting links, and a rear rivet opening of a drive link projects between the front rivet openings of two connecting links.

[0025] In particular, the connecting elements have inner side surfaces located close to the drive element and outer side surfaces located further away from it. The rivet heads of the rivet studs are located on the outer side surfaces. The second section of the rivet holes extends, in particular, to the outer side surface. Thus, every second section of a rivet hole is located close to a rivet head. The forces for deformation of the rivet stud are introduced in this area, resulting in a high degree of deformation of the rivet stud near the rivet head adjacent to the outer side surface.

[0026] The rivet pin has, in particular, a rivet collar that projects between the connecting links. With a rivet pin featuring a rivet collar, both rivet heads of the rivet pin are formed during the manufacture of the saw chain. This allows for a simple, rotationally fixed connection between the rivet pin and the connecting link on both longitudinal sides of the saw chain, thanks to the thickening according to the invention, and an increase in the strength of the connecting links.

[0027] An embodiment of the invention is explained below with reference to the drawing. The drawing shows:

[0028] Fig. 1 shows a schematic side view of a motor-driven work device,

[0029] Figs. 2 and 3 are perspective views of a connecting link.

[0030] Fig. 4 is a side view of the connecting link from Figures 2 and 3, Fig. 5 is a side view of part of a saw chain, wherein a

[0031] The drive link, a rivet bolt and a partially shown connecting link articulated to the drive link are visible.

[0032] Fig. 6 shows a section along line VI - VI in Fig. 5,

[0033] Fig. 7 shows a section along line VII - VII in Fig. 5,

[0034] Figs. 8 and 9 are perspective views of a rivet bolt of the saw chain from Figs. 5 to 7.

[0035] Figs. 10 to 12 Side views of the rivet bolt from Figs. 8 and 9,

[0036] Fig. 13 shows a connecting element according to the invention, which is designed as a cutting element.

[0037] Fig. 1 shows a chainsaw 1 as an embodiment of a motor-driven work tool. In this embodiment, the chainsaw 1 is a handheld, hand-guided chainsaw. The motor-driven work tool can also be another type of work tool, such as a tree harvester or the like. The chainsaw 1 has a housing 2 to which a rear handle 3 and, in this embodiment, a handle tube 4 are attached. A drive motor 6 is arranged in the housing 2. The drive motor 6 can be an internal combustion engine or an electric motor. A single-cylinder engine, particularly a two-stroke engine, is provided as the internal combustion engine. If the drive motor 6 is an electric motor, it is supplied with energy, in particular, by a battery. Alternatively, the drive motor 6 can also be connected to a fixed power supply via a power cable. The chainsaw 1 includes a guide bar 7 to which a saw chain 8 is arranged.During operation, the saw chain 8 is driven by the drive motor 6 in a circular motion around the guide bar 7. The saw chain 8 moves in one direction 9. The saw chain 8 comprises connecting links 10. Some of the connecting links 10 are designed as cutting links 30. The cutting links 30 each have a cutting tooth 31, which is intended for engagement with a workpiece.

[0038] A hand guard 5 is arranged on the side of the handle tube 4 facing the guide rail 7. The hand guard 5 can be used to trigger a braking device (not shown) for the saw chain 8.

[0039] Figures 2 to 4 show a connecting element 10 of the saw chain 8 according to the invention in detail. The connecting element 10 comprises two running surfaces, namely a front running surface 20 and a rear running surface 21. The running surfaces 20 and 21 are designed to contact the guide bar 7 and, during operation of a saw chain 8 equipped with the connecting element 10, bear at least partially against the guide bar 7.

[0040] The connecting link 10 has two rivet holes, namely a front rivet hole 13 and a rear rivet hole 14. The directional designations "front" and "rear" refer here to the direction of travel 9. The front rivet hole 13 is arranged leading to the rear rivet hole 14 when a saw chain 8 equipped with the connecting link 10 is in operation.

[0041] As shown in Figures 2 to 4, an indentation 28 is provided in the area between the rivet openings 13 and 14, which indicates the direction of travel 9 in the form of an arrowhead.

[0042] As shown in Fig. 4, the connecting element 10 has a bottom surface 51. The running surfaces 20 and 21 extend along the bottom surface 51. The connecting element 10 also has a top surface 52. The top surface 52 is the longitudinal side of the connecting element 10 furthest from the running surfaces 20 and 21. If the connecting element 10 is a cutting element 30, a cutting tooth 31 is attached to the top surface 52 (Fig. 1). The connecting element 10 has a front surface 53 that leads the direction of travel 9 and a rear surface 54 that trails the direction of travel 9.

[0043] The rivet holes 13 and 14 open to side surfaces 17 and 18 of the connecting member 10. In Figures 2 to 4, an outer side surface 17 of the connecting member 10 is visible. The connecting member 10 has an inner side surface 18 opposite the outer side surface 17, which is shown in Figures 6 and 7. The rivet holes 13 and 14 each have a first section 22 and a second section 23. The first section 22 opens onto the inner side surface 18 of the connecting member (Figures 6 and 7), which is not visible in Figures 2 to 4. The second section 23 opens onto the outer side surface 17.

[0044] In the first section 22, the rivet holes 13 and 14 each have a constant, cylindrical cross-section. In the second section 23, the cross-sectional area widens towards the outer side surface 17. In the exemplary embodiment, the two sections 22 and 23 adjoin each other. In this exemplary embodiment, no further longitudinal sections are provided for the rivet holes 13 and 14. In an alternative embodiment, the rivet holes 13, 14 can have one or more further longitudinal sections.

[0045] The second section 23 is formed by conical sections 29 over part of its circumference. Compared to a fully circumferential conical surface, the second section 23 is flattened at four points around its circumference. This creates thickenings 24, 25, 26, 27 in the second section 23. The course of a fully circumferential conical surface is indicated in Fig. 4 by the dashed line 39. Conical sections 29 extend between the thickenings 24 to 27. A first thickening 24 is located on the side of the rivet hole 13 that is closest to the running surface 20. The first thickening 24 is located adjacent to a bottom surface 51 (Fig. 4) of the connecting element 10. At the rivet hole 14, the first thickening 24 is located on the side of the rivet hole 14 that is closest to the running surface 21.

[0046] A second thickening 25 is arranged at each rivet hole 13, 14 adjacent to a top surface 52 of the connecting element 10 (Fig. 4). The thickening 25 is located on the side of the rivet hole 13, 14 furthest from the running surface 20 or 21.

[0047] A further thickening 26 is arranged on the side of the respective rivet opening 13, 14 that is located at the front with respect to the direction of travel 9. The thickening 26 is arranged on the side of the rivet opening 13, 14 that is closer to the front face 53.

[0048] A further thickening 27 is arranged on the rear side of the rivet openings 13, 14 in the direction of travel 9. The rear side of the rivet openings 13, 14 in the direction of travel 9 is the side closer to a rear side 54 of the connecting element 10.

[0049] In the exemplary embodiment, all four thickenings 24, 25, 26, and 27 are planar. The thickenings 24 to 27 define the rivet holes 13 and 14 with planar surfaces. The thickenings 24 to 27 run parallel to the central axes 15 and 16 of the rivet holes 13 and 14. In this exemplary embodiment, both the central axes of the cylindrical first sections 22 and the central axes of the conical sections 29 of the second section 23 coincide with the central axis 15 and 16 of the associated rivet hole 13 and 14.

[0050] At least in one plane 55 shown in Fig. 4, which runs perpendicular to the longitudinal center axis 19 through a central axis 15 or 16, a thickening 24 is arranged on the side of the rivet hole 13 or 14 closest to the running surface 20 or 21, respectively. At least one thickening 24 extends into the plane 55 on the side of the rivet hole 13 or 14 closest to the underside 51. In particular, a thickening 25 is also arranged on the opposite side of the rivet hole 13 or 14. The thickening 25 is also partially arranged in the plane 55. In the exemplary embodiment, the thickenings 24 to 26 are arranged symmetrically to the respective imaginary plane 55. Another arrangement, in particular one rotated about the respective central axis 15 or 16, may also be advantageous.

[0051] The thickenings 24 and 26 run in particular parallel to the central axes 15 and 16 respectively and parallel to a longitudinal central axis 19 of the connecting member 10. The thickenings 25 and 27 run in particular parallel to the central axes 15 and 16 and perpendicular to the longitudinal central axis 19.

[0052] The longitudinal center axis 19 is an imaginary axis that runs perpendicular to the center axes 15 and 16 of the rivet holes 13 and 14. The longitudinal center axis 19 runs centrally between the two side surfaces 17 and 18 of the connecting member 10.

[0053] As Figures 2 to 4 also show, conical sections 29 are formed between the thickenings 24 to 27 on the circumference. The thickenings 24 to 27 form thickenings opposite an imaginary, completely circumferential conical surface, which is shown in Fig. 4 at the front rivet opening 13 with a dashed line 39.

[0054] In the exemplary embodiment, the four thickenings 24 to 27 are arranged symmetrically about the central axes 15 and 16, respectively. Each thickening 24 to 27 extends over a circumferential angle α about the respective central axis 15 and 16. The circumferential angle α is, in particular, at most 120°, in particular at most 90°, and in particular at most 70° about the central axis 15 and 16. The circumferential angle α is, in particular, at least 30°, and in particular at least 40° about the central axis 15 and 16. The conical sections 29 arranged between the thickenings 24 to 27 each extend over a circumferential angle β. The circumferential angle β of the conical sections 29 is, in particular, at least 20° and in particular at most 60°.

[0055] As shown in Fig. 4, the thickenings 24 and 27 transition into the adjacent conical sections 29 with a comparatively large transition angle Σ. The transition angle Σ is measured at the transition between conical section 29 and thickening 24 to 27, forming a tangent to conical section 29 in a plane parallel to the outer side surface 17. In the exemplary embodiment, the transition angle Σ is measured at the outer side surface 17. Alternatively, the transition angle Σ can be measured in any plane parallel to the side surface 17 or 18 through a thickening 24 or 27. The transition angle Σ is an obtuse angle. In particular, the transition angle Σ is an obtuse angle in any plane parallel to the side surface 17 or 18. The transition angle Σ is, in particular, greater than 110°, and especially greater than 120°. In particular, the transition angle £ is less than 160°.In particular, the transition angle £ at each transition from a cone cut 29 to a thickening 24 to 27 is the same.

[0056] Figure 4 also shows the design of the running surfaces 20 and 21. As shown in Figure 4, the front running surface 20 is slightly shorter than the rear running surface 21. The front running surface 20 has a length r. The rear running surface 21 has a length s. The lengths r and s are measured parallel to the longitudinal center axis 19. The running surfaces 20 and 21 are flat. The running surface 20 forms an angle y with the longitudinal center axis 19. The running surface 21 forms an angle 5 with the longitudinal center axis 19. The angles y and 5 range from 0° to 10°. The lengths r and s correspond to at least half the diameter g of the rivet opening 13 and 14, respectively, in the first section 22.

[0057] Fig. 5 shows a section of the saw chain 8, namely a drive link 11 of the saw chain 8 and a section of a connecting link 10 pivotably mounted on the drive link 11 via a rivet 12. Another connecting link 10, pivotably mounted on the rivet 12, is obscured in Fig. 5 by the connecting link 10 shown. As Fig. 5 shows, the drive link 11 has a drive lug 35, which serves to engage a drive pinion or the like of the chainsaw 1. The drive lug 35 is guided in a guide groove of the guide bar 7. The drive link 11 has two rivet holes 45, one of which is visible in Fig. 5. The rivet 12, by which the connecting link 10 is pivotably mounted on the drive link 11, is arranged in the second, front rivet hole 45.

[0058] Figures 6 and 7 show sections through the central axis 16 of the connecting member 10 and the rivet bolt 12. Fig. 6 shows a section through two opposing conical sections 29. Fig. 7 shows a section in the plane 55 through the thickenings 24 and 25.

[0059] As shown in Fig. 6, the rivet pin 12 comprises a rivet collar 33 and two rivet heads 32. The rivet heads 32 bear against the outer side surfaces 17 of the two connecting members 10. The rivet collar 33 projects between the two connecting members 17. The rivet collar 33 is arranged in the rivet opening 45 of the drive member 11 and is pivotably mounted therein about the central axis 16. The rivet pin 12 is held rotationally fixed in the rivet openings 14 of the connecting members 10, at least also via the thickenings 24 to 27.

[0060] As shown in Fig. 6, the first section 22 has a diameter g. The first section 22 is at a constant distance a from the central axis 16, which corresponds to half the diameter g. The first section 22 has a width d. The width d is measured parallel to the central axis 16. In Fig. 6, the two inner side surfaces 18 of the two connecting members 10 are also visible.

[0061] As Fig. 6 shows, the second section 23 of the rivet openings 14 connects to the first.

[0062] Section 22. In the second section 23, the rivet opening 14 widens towards the outer side surface 17. The second section 23 has a maximum diameter h. The maximum diameter h is measured from one conical section 29 to an opposite conical section 29.

[0063] The second cut 23 has a maximum distance b from the central axis 16. In the exemplary embodiment, the maximum distance b corresponds to half the maximum diameter h. In Fig. 6, a cone angle r| of the cone sections 29 is also shown. The cone angle r| is measured between the wall of the cone section 29 and the central axis 16 of the rivet opening 14 (a line parallel to the central axis 16 is shown in Fig. 6). The cone angle r| is in particular less than 30°, and in particular less than 20°. In particular, the cone angle r| is at least 5°.

[0064] As shown in Fig. 6, the second section 23 has a width e measured parallel to the central axis 16. The connecting member 10 has a width f measured parallel to the central axis 16. The width e of the second section 23 is, in particular, 30% to 70% of the width f of the connecting member 10.

[0065] Figure 7 shows a section through the first thickening 24 and the second thickening 25 in the plane 55. As Figure 7 shows in conjunction with Figure 5, the first thickening 24 is located near the underside 51 and the second thickening 25 near the top side 52 of the connecting member 10. As Figure 7 shows, the thickenings 24 and 25 have a minimum distance c from the central axis 16, which corresponds to the distance a of the first section 22 from the central axis 16. In the section plane shown, the rivet opening therefore runs parallel to the central axis 16 both adjacent to the underside 51 and adjacent to the top side 52. In the exemplary embodiment, the thickenings 24 and 25 have a width t measured parallel to the central axis 16. The width t corresponds in particular to the width e of the second section 23. The thickenings 26 and 27, which are not visible in this section plane, have a corresponding width t.The width t corresponds in particular to at least 30%, and in particular to at least 40%, of the width e of the second section 23. The width t corresponds in particular to the width e of the second section 23, as shown in the exemplary embodiment. The thickenings 24 to 27 extend in particular over the entire width e of the second section 23.

[0066] The minimum and maximum dimensions are the smallest and largest dimensions, in particular diameters or distances, of the specified elements.

[0067] As shown in Fig. 7, the rivet heads 32 have an outer diameter k. The outer diameter k is larger than the diameter g of the first section 22. The outer diameter k is larger than the maximum diameter h in the second section 23. In particular, the outer diameter k is larger than the diameter i of the rivet collar 33.

[0068] The first rivet opening 13 is designed in a manner corresponding to the second rivet opening 14, so that for the design of the first rivet opening reference is made to the description of the second rivet opening 14 in Figures 5 to 7.

[0069] Figures 8 to 12 show a rivet bolt 12 in detail. The rivet bolt 12 has two rivet heads 32 and a rivet collar 33 arranged centrally between the rivet heads 32. Adjacent to the rivet collar 33 are two cylindrical first sections 37. Between each first section 37 and a rivet head 32, a second section 38 is arranged. The second sections 38 are designed as truncated cones with four flats 40 each. The four flats 40 are arranged symmetrically around a longitudinal center axis 36 of the rivet bolt 12. The flats 40 are planar and each runs parallel to the longitudinal center axis 36.

[0070] As shown in Fig. 10, the flattened sections 40 have a minimum distance m from the central axis 36. The minimum distance m corresponds to the minimum distance c in the second section 23 of the connecting member 10 (Fig. 7). The minimum distance c is at least as large, and in particular exactly as large, as half the diameter n of the first section 37. As shown in Fig. 11, the rivet pin 12 in the first section 37 has a diameter n. The diameter n corresponds to the diameter g of the first section 22 of the connecting member 10 (Fig. 6). The second section 38 of the rivet pin 12 has a maximum diameter p. The maximum diameter p corresponds to the maximum diameter h of the second section 23 of the connecting member 10 (Fig. 6).

[0071] The rivet bolt 12 shown in Figures 8 to 12 is formed by shaping a rivet bolt 12 according to the arrangement in the rivet opening 45 of a drive member 11 and in the rivet openings 13 or 14 of two paired connecting members 10. The rivet bolt 12 completely fills the rivet openings 13 or 14 of the connecting members 10.

[0072] Fig. 13 shows a connecting element 10 according to the invention, which is designed as a cutting element 30. The cutting element 30 has a cutting tooth 31. The cutting tooth 31 is arranged on the upper surface 52 of the cutting element 30. The cutting element 30 has a front running surface 20 and a rear running surface 21. The running surfaces 20 and 21 extend along the lower surface 51 of the cutting element 30. The cutting element 30 has a front rivet opening 13 and a rear rivet opening 14. The rivet openings 13 and 14 each have a first section 22 and a second section 23. The design of the rivet openings 13 and 14 with the first section 22 and the second section 23 and the design of the running surfaces 20 and 21 corresponds in particular to the design of the connecting element lO described in Figures 2 to 7, to which reference is made to avoid repetition.

[0073] The design according to the invention is particularly advantageous for a connecting element 10 designed as a cutting element 30 due to the stresses that arise in a cutting element 30 during operation. In particular, at least the connecting elements 10 designed as cutting elements 30, and especially all connecting elements 10 of a saw chain 8, have the design according to the invention. Alternatively, it can be provided that some connecting elements 10 have a different design. A different design can be particularly advantageous for connecting elements 10 that are subject to less high stress.

[0074] 5

Claims

Claims 1. Connecting link for a saw chain of a motor-driven work device, wherein the connecting link (10) has two rivet holes (13, 14), wherein the connecting link (10) has two opposing side surfaces (17, 18) to which the rivet holes (13, 14) open, wherein the connecting link (10) has a longitudinal central axis (19) that intersects the central axes (15, 16) of the rivet holes (13, 14) perpendicularly and which runs centrally between the side surfaces (17, 18), wherein the connecting link (10) has a bottom surface (51) on which at least one running surface (20, 21) designed for contact with a guide rail (7) runs, wherein at least one of the rivet holes (13, 14) has a first section (22) and a second section (23), wherein the second section (23) in particular adjoins the first section (22),wherein the first section (22) is cylindrical and the second section (23) is formed as a conical section (29) in at least one circumferential region, wherein the second section (23) extends to a side surface (17), characterized in that the second section (23) has a thickening (24) on the side of the rivet opening (13, 14) closest to the underside (51) opposite a fully circumferential conical surface, at least in an imaginary plane (55) which contains the central axis (15, 16) of the rivet opening (13, 14) and is perpendicular to the longitudinal central axis (19).

2. Connecting element according to claim 1, characterized in that the second section (23) has a further thickening (25) in the imaginary plane (55) on the side of the rivet opening (13, 14) furthest from the underside (51) opposite a completely circumferential conical surface.

3. Connecting element according to claim 1 or 2, characterized in that a transition angle (s) measured at the transition between cone section (29) and thickening (24, 25, 26, 27) is an obtuse angle, wherein the transition angle (s) is measured in a plane parallel to the side surface (17, 18) to a tangent to the cone section (29).

4. Connecting element according to one of claims 1 to 3, characterized in that the thickening (24, 25, 26, 27) has a width (t) measured parallel to the central axis (15, 16) of the rivet opening (13, 14) which corresponds to at least 30%, in particular at least 40%, of the width (f) of the connecting element (10).

5. Connecting element according to one of claims 1 to 4, characterized in that the thickening (24, 25, 26, 27) limits the rivet opening (13, 14) with a flat surface.

6. Connecting element according to one of claims 1 to 5, characterized in that the thickening (24, 25, 26, 27) extends over a circumferential angle (a) of at least 30°, in particular at least 40° about the central axis (15, 16) and / or that the thickening (24, 25, 26, 27) extends over a circumferential angle (a) of at most 120°, in particular at most 90°, in particular at most 70° about the central axis (15, 16).

7. Connecting element according to one of claims 1 to 6, characterized in that the cone angle (r|) of the cone section (29) is less than 30°, in particular less than 20°.

8. Connecting element according to one of claims 1 to 7, characterized in that the rivet opening (13, 14) has at least three, in particular at least four thickenings (24, 25, 26, 27).

9. Saw chain comprising connecting links (10) according to any one of claims 1 to 8.

10. Saw chain according to claim 9, characterized in that the connecting links (10) have inner side surfaces (18) located close to the drive link (11) and outer side surfaces (17) located farther from the drive link (11) and that the second section (23) of the rivet openings (13, 14) extends to the outer side surface (17).

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