chain link

Abstract

Roller chain (300) for a bicycle with a right and a left side, which is designed for a derailleur gear system with multiple sprockets, comprising: outer plates and inner plates (310) formed by chain links (10; 100; 200) of a first type on at least one of the two sides; wherein the chain links (10; 100; 200) of the first type have: - an inner surface (12) and an outer surface (14) opposite the inner surface (12); - two opposing end regions (16a, 16b; 116a, 116b; 216a, 216b) each with a section-wise essentially circular outer contour, wherein a circular perforation (20a, 20b; 120a, 120b; 220a, 220b) with a perforation center point (22a, 22b) is provided concentric to the outer contour; wherein a perforation axis (24) is defined by the connecting line between the two perforation centers (22a, 22b), and wherein a transverse plane (26) standing centrally perpendicular to the hole axis (24) forms a plane of symmetry of the chain link (10; 100; 200); - a connecting area (28; 128; 228) which connects the two end areas (16a, 16b; 116a, 116b; 216a, 216b), wherein the connecting area (28; 128; 228) has an edge contour that is asymmetrical with respect to the perforation axis (24) with an outer edge (30) running substantially parallel to the perforation axis (24) and an inner edge (32) that is curved towards the perforation axis (24); and - an elongated opening (34; 134; 234) in the connecting area (28; 128; 228), which has two sides (34a, 34b) running substantially parallel to the perforation axis (24); 134a, 134b; 234a, 234b) which define a central axis (34e) between each other, wherein the central axis (34e) of the opening (34; 134; 234) is displaced relative to the perforation axis (24) in the direction of the outer edge (30) of the connection area (28).

Description

[0001] The present invention relates to a roller chain for a bicycle having a right and a left side, which is adapted for a derailleur with multiple pinions.

[0002] It is known from the prior art to use roller chains as drive chains for bicycles with derailleur gears. These chains consist of chain links arranged so that they can pivot relative to one another, forming a closed chainring for transmitting drive power. Each chain link consists of a pair of inner or outer plates on a right and a left side of the roller chain, respectively. These directions are defined in the assembled state of the chain with respect to a forward direction of the bicycle equipped with the chain.

[0003] These plates, in turn, each have two end sections with a substantially round outer contour, connected by a connecting section, which often has a tapered outer contour. The end sections of the plates also have holes concentric with their outer contour. Roller chains of this type differ from those designed for bicycles without derailleur gears, such as BMX bikes, in the manner in which the inner and outer plates are connected, as discussed below.

[0004] Along the length of the chain, alternating inner and outer link plates are pivotally connected to each other at their respective chain joints by means of chain pins. These chain pins are pressed into the aforementioned holes in the outer links, while there is a certain amount of play between the holes in the inner links and the chain pins to ensure rotational mobility between the chain links.

[0005] Examples of such chains or link plates are known from DE 10 2017 009 632 A1, EP 1 617 101 A1, EP 2 535 616 B1, FR 974 976 A, US 6,110,064 A, US 9,939,045 B2 and US 10,641,356 B2, whereby the link plates presented therein differ in terms of their exact external shape and also in terms of whether or not they are provided with an opening in their connection area.

[0006] With the recent evolution of derailleur systems for bicycles, which consist of a front chainring, a roller chain, a rear multi-pinion, and associated derailleurs, the number of pinions on the multi-pinion system has gradually increased. This has been accompanied by changes in the dimensions of pinions, chain plates, chain pins, and chain rollers, as well as the corresponding forces occurring in these components. The chain is adapted to the ever-decreasing axial distances between the rear sprockets located on the rear wheel hub.

[0007] In this context, it is clear that the necessary reinforcement of the chain plates used in certain relevant sections to absorb the resulting forces increases the material requirements, which inevitably also results in an increase in the weight of the chain. However, since there is a constant effort in bicycle construction to make all components as light as possible, there is still potential for improvement in terms of optimizing the amount of material required to form the corresponding chain plates.

[0008] It is to the credit of the inventors of the present invention to have recognized that by reinforcing the chain plates in certain areas, it is possible, on the other hand, to dispense with material in correspondingly other areas and thus to make the corresponding plates lighter without weakening their structure or performance.

[0009] Accordingly, a roller chain according to the invention for a bicycle with a right and a left side, which is designed for a derailleur with multiple pinions, comprises outer plates formed on at least one of the two sides by chain plates of a first type, as well as inner plates, wherein the chain plates of the first type have: an inner surface and an outer surface opposite the inner surface, two mutually opposite end regions, each with a sectionally substantially circular outer contour, wherein concentrically to the outer contour there is provided a likewise circular hole with a hole center, wherein a hole axis is defined by the connecting section between the two hole centers, and wherein a transverse plane centrally perpendicular to the hole axis forms a plane of symmetry of the chain plate, a connecting region which connects the two end regions,wherein the connecting region has an edge contour asymmetrical with respect to the perforation axis, with an outer edge extending substantially parallel to the perforation axis and an inner edge curved (waisted) toward the perforation axis, and an elongated opening in the connecting region, which has two sides extending substantially parallel to the perforation axis, which sides define a central axis between them, wherein the central axis of the opening is displaced relative to the perforation axis in the direction of the outer edge of the connecting region.

[0010] It should be noted that outer plates and / or inner plates of the roller chain according to the invention that are not formed by the first type of link plates can be formed by at least one other type of link plate. Providing link plates of the first type on only one of the right and left sides, corresponding to a side of the chain remote from the frame and a side close to the frame, can also help to install the chain the right way round during assembly, ensuring the correct running direction of the chain.

[0011] By providing the elongated opening in the connecting region, which is offset toward the outer edge of the connecting region running essentially parallel to the hole axis, it is possible to create closed lines of force on both sides thereof between the two opposing end regions and thus ensure the structural strength of the link plate according to the invention even with reduced material expenditure. Although some of the prior art publications cited above also disclose link plates in which individual openings are provided, these are all positioned symmetrically to the hole axes of the respective link plates, which would no longer allow optimal force distribution in the link plate according to the invention with its connecting region asymmetrical with respect to the hole axis.

[0012] Thus, the roller chain according to the invention and the use of corresponding chain plates of the first type achieve, on the one hand, a weight reduction by providing the elongated opening in the connection area, while, on the other hand, the asymmetrical outer contour achieves a reduction in the width of the chain plate while at the same time achieving optimal force absorption, in particular with regard to bending loads, which enables the use of the chain constructed from it with pinions arranged very closely to one another.

[0013] In particular, in actual use of the roller chain according to the invention with the chain plates of the first type, a balanced tension can be achieved on both sides of the opening in the connection area, while further advantageous developments of the first type of chain plate in roller chains according to the invention are discussed below, which relate in particular to the concrete design of individual areas and geometric relationships thereof.

[0014] For example, the opening can be located entirely on the side of the hole axis facing the outer edge in the connecting area, but embodiments are also conceivable in which the hole axis can coincide with the corresponding side of the opening. The optimal choice of the opening position ultimately depends on its dimensions, the waist of the connecting area, and the thickness of the link plate between its inner and outer surfaces.

[0015] Furthermore, the opening can be designed trapezoidally, with the side facing the outer edge of the connecting area being longer than the side facing the inner edge. This takes into account the fact that the opening approaches the perforations at both ends relative to the perforation axis. Its trapezoidal design ensures that the distances between the opening and the two perforations on the respective sides vary only within a small range, if at all, in order to avoid stress or force peaks at these points.

[0016] This can even be done so far that the sides of the opening facing the end regions are designed as circular arc sections running concentrically to the perforations, which then allows a substantially constant distance between the opening and the corresponding perforation on the respective side to be achieved in these regions. However, a straight design of the sides of the opening facing the end regions is of course also possible, for example, which could, in particular, be parallel to a tangent to the corresponding perforation in this region.

[0017] Furthermore, to avoid stress or force peaks, the corners of the opening can be rounded, which can also allow easier processing of the chain plate.

[0018] With regard to the thickness of the material of the link plate, this can also be tailored to the expected forces acting on the link plate in sections, for example, having a first thickness in a circular area around the holes and a second thickness in the connecting area, with the first thickness being greater than the second thickness. Furthermore, a transition area can be provided between the area with the first thickness and the area with the second thickness, which ensures a smooth transition between the two thicknesses and prevents the occurrence of sharp edges.

[0019] With regard to the position of the opening, the distance between the side of the opening facing the outer edge and the outer edge at the level of the transverse plane can be less than half the distance between the side of the opening facing the inner edge and the inner edge. This provision ensures that, with a more pronounced waistline of the link plate in its connecting area, the opening also moves further toward the rectilinear outer edge, thus ensuring the effect according to the invention.

[0020] Alternatively or additionally, at the level of the transverse plane, the distance between the side of the opening facing the outer edge and the outer edge can be smaller than the distance between the side of the opening facing the outer edge and the side of the opening facing the inner edge. This measure, in turn, establishes a relationship between the dimensions of the opening itself and its position relative to the edges of the connecting area, so that even with differing dimensions of the opening in different embodiments, its position within the connecting area can always be optimally ensured.

[0021] Furthermore, at the level of the transverse plane, the distance between the side of the opening facing the outer edge and the outer edge can be more than twice the thickness of the link plates. By selecting this ratio appropriately, a relationship can be established between the material thickness in the central area of ​​the connection and the specific position of the opening relative to the outer edge of the link plate. This specification thus prevents the material web provided between the opening and the outer edge from being too thin or too weak.

[0022] Furthermore, in the roller chain according to the invention, the holes in the chain plates of the first type can be surrounded by collar sections extending cylindrically from the inner surface, whereby the roller chain is particularly suitable for use in bicycles with derailleur gears.

[0023] Although, as already mentioned above, in the roller chain according to the invention the link plates of the first type can be provided as outer links only on one of the two sides thereof, it is also conceivable to form the outer links on both sides thereof by link plates of the first type and / or to form the inner links by link plates of the first type.

[0024] Further features and advantages of the present invention will become more apparent from the following description of an embodiment thereof, when considered together with the accompanying figures. These show in detail: Fig. 1 a plan view of an embodiment of a chain link plate which can be used in a roller chain according to the invention; Fig. 2 a cross section through the chain plate Fig. 1 in the area of ​​its transverse plane according to arrow II Fig. 1; Fig. 3 a detailed view of the opening of the chain plate from the Fig. 1 and Fig. 2; Fig. 4 a plan view of a second embodiment of a link plate which can be used in a roller chain according to the invention; Fig. 5 is a plan view of a third embodiment of a link plate which can be used in a roller chain according to the invention; and Fig. 6 a schematic isometric view of a section of a roller chain according to the invention.

[0025] In Fig. 1 shows a first embodiment of a chain plate which can be used in a roller chain of a bicycle according to the invention, in a plan view and is generally designated by the reference numeral 10. In the Fig. 1, the inner surface 12 of the chain plate is shown, for example in Fig. 2 also designates the outer surface 14.

[0026] Furthermore, the link plate 10 comprises mutually opposite end regions 16a and 16b, each with a substantially circular outer contour in sections, which have respective flattened portions 18a and 18b only at their outermost ends. Concentric with the circular portions of the outer contours 16a and 16b, a respective circular perforation 20a and 20b is provided, each with respective perforation centers 22a and 22b and collar portions 20c extending cylindrically from the inner surface 12, which surround the perforations 20a and 20b.

[0027] By drawing a connecting line between the two hole centers 22a and 22b, a hole axis 24 can be defined, which divides the link plate into two asymmetrical areas. Furthermore, a transverse plane 26 can be defined, which is centrally perpendicular to the hole axis 24 and along which the cross section of Fig. 2, which will be discussed in more detail below. This transverse plane 26 forms a plane of symmetry of the chain plate 10 and also divides it into two areas.

[0028] Here, the transverse plane 26 lies with respect to the chain link 10 in the region of a connecting region 28 which connects the two end regions 16a and 16b to one another and which has an edge contour which is asymmetrical with respect to the perforation axis 24 and has an outer edge 30 which runs essentially parallel to the perforation axis 24 and an inner edge 32 which is curved or tapered towards the perforation axis 24.

[0029] Furthermore, Fig. 1 that the link plate 10 is provided in the region of its connecting region 28 with an elongated opening 34. This opening has two sides 34a and 34b running essentially parallel to the hole axis, as well as two sides 34c and 34d facing the end regions, which are each connected to one another by rounded corners. Furthermore, a central axis 34e of the opening 34 is defined centrally between the two sides 34a and 34b. This central axis 34e runs parallel to the hole axis 24, but is offset from it in the direction of the outer edge 30 of the connecting region 28.

[0030] Fig. 2 now shows a sectional view of the chain plate 10 in the area of ​​the transverse plane 26 according to the arrow II from Fig. 1, in which, as mentioned, the inner surface 12 and the outer surface 14 of the link plate 10 are shown opposite one another. Furthermore, it can be seen that in this sectional view, the thickness of the material of the link plate 10 decreases toward its edges, thus correspondingly chamfering the link plate 10 toward the edges of the connecting region 28. This chamfer can, in an operating state of the link plate, help facilitate shifting operations from one pinion to an adjacent pinion, making the link plate 10 shown particularly suitable for shifting values ​​with a large number of pinions.

[0031] Also in the sectional view from Fig. 2 again shows that the central axis 34e of the opening 34 is offset from the perforation axis 24, to such an extent that even the side 34b of the opening 34 facing the inner edge 32 lies above the perforation axis 24.

[0032] At this point it should also be noted that the chain link plate 10 shown has a first thickness between its inner surface 12 and its outer surface 14 in the circular areas 16a and 16b around the holes 20a and 20b and a second thickness in the connecting area 28, which accordingly Fig. 2 and which is less than the first strength.

[0033] Furthermore, it should be noted that the opening 34 lies entirely in the area of ​​this second thickness and accordingly does not overlap with the chamfer 36 in the area of ​​its two edges 30 and 32. Corresponding chamfers can also be provided in the end areas 16a and 16b, at least in sections, on the respective edge of the link plate 10, but are not shown in the plan view. Fig. 1 not shown for reasons of clarity.

[0034] Now let’s Fig. 3, which shows a detailed view of the opening 34. It can be seen in particular that the two sides 34c and 34d, i.e. the sides of the opening 34 facing the end regions 16a and 16b, are designed as circular arc sections running concentrically to the perforations 20a and 20b, which makes it possible to achieve a substantially constant distance between the corresponding side of the opening 34 and the respective perforation 20a or 20b.

[0035] In the Fig. 4 and Fig. 5 shows a second and a third embodiment of a link plate, respectively, which can be used in a roller chain according to the invention. The two link plates from the Fig. 4 and Fig. 5 are designated by the reference numerals 100 and 200 and only the differences between these second and third embodiments and the first embodiment from the Fig. 1 to 3 should be explained.

[0036] For this purpose, similar or identical components of the chain plates from the Fig. 4 and Fig. 5 with the same reference numerals as in Fig. 1, increased by 100 or 200 respectively. Furthermore, to avoid duplication, the repeated description of identical components is omitted and in this context reference is made to the above detailed description of the first embodiment, which, apart from the differences discussed below, is identical to the embodiments from the Fig. 4 and Fig. 5 is correct.

[0037] The embodiments from the Fig. 4 and Fig. 5 differ from that of Fig. 1 only with regard to the design of their respective openings 134 and 234.

[0038] First, the chain plate 100 from Fig. 4, whose opening 134 has a similar trapezoidal shape with four sides 134a-134d and rounded corners, but whose sides 134a and 134b are overall shorter than the corresponding sides 34a and 34b of the first embodiment. Thus, the opening 134 extends only in the connecting region 128 and does not reach the end regions 116a and 116b around the perforations 120a and 120b with the increased thickness compared to the connecting region 128.

[0039] In contrast, the opening 234 of the embodiment extends from Fig. 5, both in the connecting region 228 and the end regions 116a and 116b around the perforations 120a and 120b, it has a fundamentally different external shape. Here, the two sides 234a and 234b are of equal length, and the sides 234c and 234d are formed merely by semicircles that connect the long sides 234a and 234b. Thus, the opening 234 has a further axis of symmetry compared to the openings 34 and 134 of the other embodiments.

[0040] Most recently, Fig. 6 a schematic isometric view of a section of a roller chain 300 according to the invention with pairs of outer plates 10 according to the embodiment of the Fig. 1 to 3, as well as pairs of inner plates 310, which are connected to one another in a known manner to form a roller chain suitable for a derailleur with multiple pinions. It should be noted that the inner plates 310 are formed similarly to the outer plates 10 in terms of their external shape and each have a straight side 330 and a tapered side 332.

[0041] By the straight sides 30 and 330 of the outer plates 10 and inner plates 310 both at the in Fig. 6 upper side of the roller chain 300, on the one hand an optimal force distribution within and between the plates and on the other hand excellent running properties of the roller chain 300 are achieved.

[0042] It should also be noted that in roller chains according to the invention, the chain plates 10 of the first type described above are provided with the openings 34 only on one of the two right and left sides (corresponding to the front and rear plates of the plate pairs in Fig. 6) thereof may be provided as outer plates, however, it is also conceivable to form the outer plates on both sides thereof by link plates of this first type and / or to form the inner plates by link plates of this first type, while the remaining link plates may be formed by other types, which for example do not have any openings, which is not possible in the Fig. 6 applies to the inner plates 310.

Claims

[1] Roller chain (300) for a bicycle having a right and a left side, which is adapted for a derailleur with multiple pinions, comprising: outer plates and inner plates (310) formed on at least one of the two sides by chain plates (10; 100; 200) of a first type; wherein the link plates (10; 100; 200) of the first type comprise: - an inner surface (12) and an outer surface (14) opposite the inner surface (12); - two opposite end regions (16a, 16b; 116a, 116b; 216a, 216b) each having a substantially circular outer contour in sections, wherein a likewise circular hole (20a, 20b; 120a, 120b; 220a, 220b) with a hole center point (22a, 22b) is provided concentrically to the outer contour; wherein a hole axis (24) is defined by the connecting line between the two hole centers (22a, 22b), and wherein a transverse plane (26) centrally perpendicular to the hole axis (24) forms a plane of symmetry of the chain plate (10; 100; 200); - a connecting region (28; 128; 228) which connects the two end regions (16a, 16b; 116a, 116b; 216a, 216b), wherein the connecting region (28; 128; 228) has an edge contour which is asymmetrical with respect to the perforation axis (24) and has an outer edge (30) which runs substantially parallel to the perforation axis (24) and an inner edge (32) which is curved towards the perforation axis (24); and - an elongated opening (34; 134; 234) in the connecting region (28; 128; 228) which has two sides (34a, 34b; 134a, 134b; 234a, 234b) which define a central axis (34e) between each other, wherein the central axis (34e) of the opening (34; 134; 234) is displaced relative to the perforation axis (24) in the direction of the outer edge (30) of the connecting region (28). [2] Roller chain (300) according to claim 1, wherein in the chain plates (10; 100; 200) of the first type, the opening (34; 134; 234) lies entirely on the side of the hole axis (24) facing the outer edge (30). [3] Roller chain (300) according to one of the preceding claims, wherein in the chain plates (10; 100) of the first type, the opening (34; 134) is trapezoidal in shape, in that the side (34a; 134a) thereof facing the outer edge (30) of the connecting region (28) is longer than the side (34b; 134b) facing the inner edge (32). [4] Roller chain (300) according to one of the preceding claims, wherein in the chain plates (10; 100) of the first type, the sides (34c, 34d; 134c; 134d) of the opening (34; 134) facing the end regions (16a, 16b; 116a, 116b) are formed as circular arc sections running concentrically to the perforations (20a, 20b; 120a, 120b). [5] Roller chain (300) according to one of the preceding claims, wherein in the chain plates (10; 100) of the first type the corners of the opening (34; 134) are rounded. [6] Roller chain (300) according to one of the preceding claims, wherein in the link plates (10; 100; 200) of the first type, the link plate (10; 100; 200) has a first thickness in a circular area around the holes (20a, 20b; 120a, 120b; 220a, 220b) and has a second thickness in the connecting area (28; 128; 228), the first thickness being greater than the second thickness. [7] Roller chain (300) according to claim 6, wherein a transition region is provided in the chain plates (10; 100; 200) of the first type between the region with the first thickness and the region with the second thickness. [8] Roller chain (300) according to one of the preceding claims, wherein in the link plates (10) of the first type at the level of the transverse plane (26) the distance between the side (34a) of the opening (34) facing the outer edge (30) and the outer edge (30) is less than half the distance between the side of the opening (34) facing the inner edge (32) and the inner edge (32). [9] Roller chain (300) according to one of the preceding claims, wherein in the link plates (10) of the first type, at the level of the transverse plane (26), the distance between the side (34a) of the opening (34) facing the outer edge (30) and the outer edge (30) is less than the distance between the side (34a) of the opening (34) facing the outer edge (30) and the side (34b) of the opening (34) facing the inner edge (32). [10] Roller chain according to one of the preceding claims, wherein in the link plates (10) of the first type, at the level of the transverse plane (26), the distance between the side (34a) of the opening (34) facing the outer edge (30) and the outer edge (30) is more than twice the thickness of the link plate. [11] Roller chain according to one of the preceding claims, wherein in the chain plates (10) of the first type the holes (20a, 20b) are surrounded by collar sections (20c) extending cylindrically from the inner surface. [12] Roller chain according to one of the preceding claims, wherein on both sides thereof the outer plates are formed by chain plates (10; 100; 200) of the first type. [13] Roller chain according to one of the preceding claims, wherein the inner plates are also formed by chain plates (10; 100; 200) of the first type.

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