bicycle chainring and bicycle crank assembly

Abstract

bicycle chainring (12) comprising: a sprocket body (20) having a rotational axis (A1), a first side (42) and a second side (44) opposite the first side (42) in an axial direction (D2) parallel to the rotational axis (A1); and A chain engagement structure (22) which is / will be arranged on an outer periphery of the sprocket body (20), wherein the chain engagement structure (22) includes a plurality of sprocket teeth (24) which extend radially outwards from the outer periphery of the sprocket body (20), wherein the plurality of sprocket teeth (24) includes at least one first tooth (26) and at least one second tooth (28), wherein the at least one first tooth (26) has a first tooth tip (30) which extends non-parallel to a sprocket plane (P1) perpendicular to the axis of rotation (A1) when viewed from a radial direction of the bicycle sprocket (12), wherein the at least one first tooth (26) has a first axial chain engagement width (W1) which is larger than an inner connection space (S1) which is defined between a pair of inner connection plates of a bicycle chain (C) and is smaller than an outer connection space (S2),which is defined between a pair of outer connecting plates of the bicycle chain (C), and wherein at least one second tooth (28) has a second axial chain engagement width (W2) which is smaller than the inner connecting space (S1).

Description

Background of the invention

[0001] This application claims priority from US patent application No. 14 / 667,601, filed on March 24, 2015. The entire disclosure of US patent application No. 14 / 667,601 is hereby fully incorporated by reference herein. Field of invention

[0002] The present invention relates to a bicycle chainring and a bicycle crank assembly. background

[0003] Cycling is becoming an increasingly popular form of recreation and transportation. It has also become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation, or competition, the bicycle industry has constantly improved various bicycle components. One bicycle component that has been extensively redesigned is the chainring.

[0004] US 2013 / 0139642A1 describes a single chainring for a bicycle front crank assembly for engaging a drive chain, comprising a plurality of teeth formed around the circumference of the chainring, wherein the plurality of teeth has an even number of teeth. The plurality of teeth includes a first group of teeth and a second group of teeth arranged alternately between the first group of teeth.

[0005] EP 1 764 296 A1 describes a gear for a bicycle drive train which has a flat shape between two opposite sides with a central section surrounded by a circumferential section, the circumferential section containing a plurality of teeth.

[0006] US 6 139 456 A describes a bicycle chainring with a number of ring-shaped, equidistant teeth formed on its outer circumference, wherein the teeth on the chainring are diametrically symmetrical.

[0007] DE 296 10 398 U1 describes a chainring for driving the rear wheel of a bicycle, wherein two or more chainrings interact with a chain and are arranged at a certain distance from each other.

[0008] US 4 181 033 A describes chainrings for a bicycle, each with a disc and a number of teeth protruding from its outer circumference for engagement with a drive chain to transmit the drive from a pedal crank to the rear wheel of the bicycle.

[0009] DE 691 10 800 T2 describes a multi-stage chainring assembly for a bicycle, which has a small chainring, a large chainring arranged coaxially to the small chainring and a shifting aid projection provided on the large chainring to support the movement of a chain when switching from the small chainring to the large chainring.

[0010] DE 10 2011 013 695 A1 describes a drive unit on the rear wheel of a bicycle with a sprocket of a multi-sprocket arrangement and a roller chain, wherein the sprocket is made of a light but softer material, and in which shifting aids in the form of recesses and grooves on the sprocket teeth are avoided where the chain rollers are in contact with the load flanks of the teeth.

[0011] DE 103 47 784 A1 describes a derailleur system for bicycles, comprising a driving and a driven chainring unit, a chain for transmitting the drive force and a derailleur for initiating the shifting process, wherein at least one tooth group with a reference tooth, a subsequent tooth and at least one catch tooth is arranged on the larger chainring, which have a suitable tooth shape to improve the shifting process from the smaller to the larger chainring and to reduce the shifting noise.

[0012] DE 43 30 989 A1 describes a derailleur system, in particular for bicycles, comprising a driving sprocket unit and a driven sprocket unit as well as a chain connecting these two sprocket units, wherein at least one of the sprocket units is designed as a multi-sprocket unit with at least two sprockets, namely a larger and a smaller sprocket, and wherein the two sprockets of the multi-sprocket unit each have a plurality of teeth and a corresponding plurality of tooth gaps formed between each pair of teeth.

[0013] EP 0 002 903 B1 describes a multi-stage gear system for a wheel consisting of a crankshaft, a pair of crank arms attached to the opposite axle ends of said crankshaft, and at least one gear with a larger diameter and at least one gear with a smaller diameter, wherein said gears are attached for rotation with one of said crank arms and have a plurality of teeth for meshing with a drive chain. Summary of the invention

[0014] Against this background, the invention is based on the technical problem of providing an improved bicycle chainring and an improved bicycle crank assembly.

[0015] This technical problem is solved by a bicycle chainring according to a first aspect of the present invention. The bicycle chainring comprises a chainring body and a chain engagement structure. The chainring body has a central axis of rotation, a first side, and a second side, opposite the first side in an axial direction parallel to the central axis of rotation. The chain engagement structure is arranged on an outer periphery of the chainring body. The chain engagement structure includes a plurality of chainring teeth extending radially outward from the outer periphery of the chainring body. The plurality of chainring teeth includes at least one first tooth and at least one second tooth. The at least one first tooth has a first tooth tip that extends non-parallel to a chainring plane perpendicular to the central axis of rotation when viewed from a radial direction of the bicycle chainring.The first tooth, at least, has a first axial chain engagement width that is larger than the inner connection space defined between a pair of inner connection plates of a bicycle chain, and smaller than the outer connection space defined between a pair of outer connection plates of the bicycle chain. The second tooth, at least, has a second axial chain engagement width that is smaller than the inner connection space.

[0016] Preferably, at least one first tooth includes a multitude of teeth and / or at least one second tooth includes a multitude of second teeth.

[0017] Preferably, the total number of teeth should be an even number.

[0018] Preferably, the total number of the first tooth(s) should equal the total number of the second tooth(s).

[0019] Preferably, the second teeth are arranged alternately or intermittently among the multitude of first teeth.

[0020] Preferably, the first tooth tip is inclined relative to the chain plane.

[0021] Preferably, the first tooth tip has a first leading edge and a first trailing edge. The first leading edge can be positioned downstream of the first trailing edge in a drive direction of rotation of the bicycle chainring. A first straight center line can be defined to connect the first leading edge with the first trailing edge and is non-parallel to the chainring plane.

[0022] Preferably, the first tooth(s) have a leading recess and a trailing recess. The leading recess prevents excessive contact of at least one first tooth with an inner connecting plate of the bicycle chain. The leading recess can be provided at least partially on the first leading edge. The trailing recess prevents excessive contact of at least one first tooth with another inner connecting plate of the bicycle chain. The trailing recess can be provided at least partially on the first trailing edge.

[0023] Preferably, the chainring plane is a center chainring plane, which is defined to bisect the bicycle chainring.

[0024] Preferably, at least one second tooth has a second tooth tip that extends parallel to the sprocket plane.

[0025] Preferably, the second tooth(s) has / have a second tooth tip that extends parallel to the sprocket plane.

[0026] Preferably, the second tooth(s) has / have a second tooth tip. The second tooth tip can include a second leading edge and a second trailing edge. The second leading edge can be positioned downstream of the second trailing edge with respect to the drive direction of rotation. A second straight centerline can be defined to connect the second leading edge to the second trailing edge and can be parallel to the center sprocket plane.

[0027] Preferably, the first leading edge is positioned closer to the first side than the first trailing edge in the axial direction. The first trailing edge can be positioned closer to the second side than the first leading edge.

[0028] Preferably, the first leading edge is positioned closer to the second side than the first trailing edge in the axial direction. The first trailing edge can also be positioned closer to the first side than the first leading edge.

[0029] Preferably, at least partially, the first leading edge of a tooth base projects in the axial direction into a plane formed by the first side and the second side.

[0030] Preferably, at least partially, the first trailing edge projects from the tooth base in the axial direction into the other side from the first and second sides.

[0031] Preferably, at least partially, the first trailing edge projects from the tooth base in the axial direction into a plane formed by the first side and the second side.

[0032] Preferably, a first maximum leading distance, defined between the first leading edge and the center sprocket plane in the axial direction, is either equal to or different from a first maximum trailing distance, defined between the first trailing edge and the center sprocket plane in the axial direction.

[0033] Preferably, the first maximum leading distance is either larger or smaller than the first maximum trailing distance.

[0034] Preferably either the first side or the second side is closer to a bicycle frame than the second side in the axial direction, in a state where the bicycle chainring is / is mounted to the bicycle frame.

[0035] Preferably, the first straight center line is either inclined or perpendicular to the sprocket plane.

[0036] Preferably, the first teeth include at least a third tooth and at least a fourth tooth. A third angle of inclination can be defined between the first straight centerline of the at least third tooth and the center sprocket plane on a downstream side of the drive direction of rotation and can be defined at a position closer to the first side than to the second side. A fourth angle of inclination can be defined between the first straight centerline of the at least fourth tooth and the center sprocket plane on the downstream side of the drive direction of rotation and can be defined at a position closer to the first side than to the second side. The third angle of inclination can differ from the fourth angle of inclination.

[0037] Preferably, the first tilt angle is defined between the first straight centerline and the center sprocket plane on a downstream side of the drive direction of rotation and can be defined at a position closer to the first side than to the second side. A second tilt angle can be defined between the second straight centerline and the center sprocket plane on the downstream side of the drive direction of rotation and can be positioned closer to the first side than to the second side. The second tilt angle is either equal to or less than the first tilt angle.

[0038] Preferably, the maximum longitudinal length of the second tooth tip is smaller than the maximum longitudinal length of the first tooth tip when viewed from a radial direction of the bicycle chainring.

[0039] Preferably, the bicycle chainring also includes a crank arm mounting section.

[0040] Preferably, at least one first tooth is positioned adjacent to at least one second tooth, without a tooth in between.

[0041] The technical problem is further solved by a bicycle crank assembly according to another aspect of the present invention. The bicycle crank assembly comprises a bicycle chainring according to the invention.

[0042] Preferably, the bicycle chainring is a single chainring for the bicycle crank assembly. Brief description of the drawings

[0043] A more complete appreciation of the invention and many of its associated advantages will become immediately apparent once it is better understood by reference to the following detailed description, when viewed in conjunction with the accompanying drawings, wherein: Fig. 1 is an elevation view of the bicycle crank assembly including a bicycle chainring according to a first embodiment; Fig. Figure 2 is a perspective view of the bicycle chainring illustrated in Fig. 1; Fig. Figure 3 is a perspective view of the bicycle chainring illustrated in Fig. 1; Fig. Figure 4 is a partial top view of the first tooth of the bicycle chainring, illustrated in Fig. 1, when viewed from a radial direction of the bicycle chainring; Fig. Figure 5 is a partial cutaway view of the first tooth of the bicycle chainring, illustrated in Fig. 1; Fig. 6 is a partial top view of a second tooth of the bicycle chainring illustrated in Fig. 1, when viewed from a radial direction of the bicycle chainring; Fig. 7 is a partial cutaway view of the second tooth of the bicycle chainring illustrated in Fig. 1; Fig. Figure 8 shows a partial top view of the bicycle chainring illustrated in Fig. 1, with the engagement of a bicycle chain, when viewed from a radial direction of the bicycle chainring; Fig. Figure 9 is a partial perspective view of the first tooth of the bicycle chainring, illustrated in Fig. 1; Fig. Figure 10 is a partial perspective view of the first tooth of the bicycle chainring illustrated in Fig. 1; Fig. 11 is an elevation view of a bicycle crank assembly including a bicycle chainring according to a second embodiment; Fig. Figure 12 is a perspective view of the bicycle chainring illustrated in Fig. 11; Fig. Figure 13 is a perspective view of the bicycle chainring illustrated in Fig. 11; Fig. Figure 14 shows a partial top view of the first tooth of the bicycle chainring, illustrated in Fig. 11, when viewed from a radial direction of the bicycle chainring; Fig. 15 is an elevation view of a bicycle crank assembly including a bicycle chainring according to a third embodiment; Fig. Figure 16 shows a partial top view of the first tooth of the bicycle chainring, illustrated in Fig. 15, when viewed from a radial direction of the bicycle chainring; Fig. Figure 17 shows a partial top view of the first tooth of the bicycle chainring, illustrated in Fig. 15, when viewed from a radial direction of the bicycle chainring (modified embodiment); Fig. Figure 18 is a partial top view of a bicycle chainring according to a fourth embodiment, when viewed from a radial direction of the bicycle chainring; Fig. 19 is an elevation view of a bicycle crank assembly including a bicycle chainring according to a fourth embodiment; Fig. Figure 20 is a partial top view of a bicycle chainring according to a fifth embodiment, when viewed from a radial direction of the bicycle chainring; Fig. Figure 21 is a partial top view of a bicycle chainring according to a sixth embodiment, viewed from a radial direction of the bicycle chainring; Fig. 22 is a partial top view of the second tooth of a bicycle chainring illustrated in Fig. 21, when viewed from a radial direction of the bicycle chainring; Fig. Figure 23 is a partial top view of a bicycle chainring according to a seventh embodiment, viewed from a radial direction of the bicycle chainring; and Fig. Figure 24 shows exemplary arrangements of a first tooth and a second tooth. Description of the embodiments

[0044] The embodiments are now described with reference to the attached drawings, where similar reference numerals denote the corresponding or identical elements across the different drawings. First embodiment

[0045] Firstly, referring to Fig. 1. A bicycle crank assembly 10 comprises a bicycle chainring 12 according to a first embodiment. The bicycle chainring 12 is rotatable about a rotational axis A1 relative to a bicycle frame F ( Fig. 8) In the illustrated embodiment, the bicycle chainring 12 is a single chainring for the bicycle crank assembly 10. However, the bicycle crank assembly 10 can include a plurality of bicycle chainrings if required and / or desired. In such an embodiment, at least one of the bicycle chainrings can have substantially the same construction as the bicycle chainring 12. A shifting support area (not shown) is provided on the bicycle chainring 12 to assist shifting the bicycle chain C between the bicycle chainring 12 and another chainring. While the bicycle chainring 12 is being mounted on the bicycle crank assembly 10, structures of the bicycle chainring 12 can be mounted on a rear bicycle chainring assembly if required and / or desired.

[0046] In the present application, directional terms such as "front", "back", "forward", "backward", "left", "right", "across", "upward", "downward", and any similar directional terms refer to directions determined by a user (e.g., a rider) seated on a bicycle saddle (not shown) facing a handlebar (not shown). Accordingly, these terms, as used to describe the bicycle chainring 12 of the bicycle crank assembly 10, should be interpreted as referring to a bicycle equipped with the bicycle chainring 12 and used in an upright riding position on a horizontal surface.

[0047] As in Fig. As shown in Figure 1, the bicycle crank assembly 10 comprises a chainring mounting link 14 and a crank arm 16. The chainring mounting link 14 includes crank connecting arms 14a. The bicycle chainring 12 further comprises a crank arm mounting section. In the illustrated embodiment, the bicycle chainring 12 further comprises crank arm mounting sections 18. The crank connecting arms 14a are each fastened to the crank arm mounting sections 18 by fasteners such as bolts (not shown). The chainring mounting link 14 is mounted to the crank arm 16 so that it can rotate integrally with the crank arm 16 about the axis of rotation A1. The chainring mounting link 14 can also be provided integrally with the crank arm 16 as a single unit. The bicycle chainring 12 is designed to rotate integrally with the chainring mounting link 14 and the crank arm 16 about the axis of rotation A1.The bicycle chainring 12 is designed to rotate in a drive direction D11 with respect to the axis of rotation A1 during pedaling or cycling. The drive direction D11 is defined along a circumferential direction D1 of the bicycle chainring 12.

[0048] As in Fig. As shown in Figure 1, the bicycle chainring 12 comprises a chainring body 20 and a chain engagement structure 22. The chainring body has the axis of rotation A1. While the chainring body 20 has an annular shape in the illustrated embodiment, it can have other shapes if required and / or desired. The chain engagement structure 22 is arranged on an outer periphery of the chainring body 20. The chain engagement structure 22 includes a plurality of chainring teeth 24 extending radially outward from the outer periphery of the chainring body 20. The plurality of chainring teeth 24 are arranged in a circumferential direction D1. The plurality of chainring teeth 24 includes at least one first tooth 24 and at least one second tooth 28. The at least one first tooth 26 is positioned adjacent to the at least one second tooth 28 without any intervening tooth.

[0049] In the illustrated embodiment, the at least one first tooth 26 comprises a plurality of first teeth 26, and the at least one second tooth 28 comprises a plurality of second teeth 28. The total number of the plurality of sprocket teeth 24 is an even number. The total number of the at least one first tooth 26 is equal to the total number of the at least one second tooth 28. The plurality of second teeth 28 are arranged alternately among the plurality of first teeth 26.

[0050] For example, the bicycle chainring 12 comprises thirty-two chainring teeth 24. The bicycle chainring 12 comprises sixteen first teeth 26 and sixteen second teeth 28. However, the total number of chainring teeth 24, the total number of at least one first tooth 26, and the total number of at least one second tooth 28 are not limited to the illustrated embodiment. The total number of chainring teeth 24 can be an odd number if required and / or desired. The total number of at least one first tooth 26 can differ from the total number of at least one second tooth 28 if required and / or desired.

[0051] Furthermore, the multiple teeth of the chainring (24) can be partially omitted from the bicycle chainring (12) if required and / or desired. The bicycle chainring (12) can include a first tooth (26) if required and / or desired. The bicycle chainring (12) can include a second tooth (28) if required and / or desired. The first teeth (26) can be partially replaced by second teeth (28) if required and / or desired. The second teeth (28) can be partially replaced by the first teeth (26) if required and / or desired. The bicycle chainring (12) can have at least one tooth with a shape different from the shape of the first teeth (26) and the shape of the second teeth (28) if required and / or desired.

[0052] As in the Fig. 2 and Fig. As can be seen in Figure 3, each of the plurality of second teeth 28 has a flat or planar shape. Conversely, each of the plurality of first teeth 26 has a twisted or warped shape. In the illustrated embodiment, the plurality of first teeth 26 have the same shape relative to each other. The plurality of second teeth 28 have the same shape relative to each other. The plurality of first teeth 26 has a different shape than the plurality of second teeth 28. The bicycle chainring 12 is, for example, made of a metallic material. The bicycle chainring 12 is formed, for example, by pressing and stamping. While the bicycle chainring 12 is provided integrally as a single unit link in the illustrated embodiment, the bicycle chainring 12 can have a plurality of separate links made of different materials if required and / or desired.

[0053] As in Fig. As can be seen in Figure 4, at least one tooth 26 has a first axial chain engagement width W1. The first axial chain engagement width W1 is larger than an inner connection space S1, which is defined between a pair of inner connection plates C1 of a bicycle chain C, and smaller than an outer connection space S2, which is defined between a pair of outer connection plates C2 of the bicycle chain C.

[0054] As in the Fig. 4 and Fig. As can be seen in Figure 5, at least one first tooth 26 has a first tooth tip 30. The first tooth tip 30 is located at a radially outermost end of the first tooth 26 ( Fig. 5) provided. As in Fig. As can be seen in Figure 4, the first tooth tip 30 does not extend parallel to a sprocket plane P1, which is perpendicular to an axis of rotation A1, when viewed from a radial direction of the bicycle sprocket 12. In the illustrated embodiment, the first tooth tip 30 is inclined with respect to, or in relation to, the sprocket plane P1. The sprocket plane P1 can be a center sprocket plane defined to bisect the bicycle sprocket 12. Consequently, the sprocket plane P1 can be referred to as the center sprocket plane P1.

[0055] As in Fig. As can be seen in Figure 5, the first tooth tip 30 has a first leading edge 32 and a first trailing edge 34. The first leading edge 32 is positioned downstream of the first trailing edge 34 in the drive direction D11 of the bicycle chainring 12. The first leading edge 32 has a round shape when viewed from an axial direction, the two edges parallel to the axis of rotation A1 ( Fig. 4) considered. The first leading edge 34 has a rounded shape when viewed from the axial direction D2 ( Fig. 4) considered. The first leading edge 32 has a radius smaller than the radius of the first trailing edge 34 when viewed from the axial direction D2 ( Fig. 4) considered.

[0056] As in Fig. As can be seen in Figure 4, a first straight center line CL1 is defined to connect the first leading edge 32 with the first trailing edge 34 and is not parallel to the sprocket plane P1. The first straight center line CL1 is inclined with respect to the sprocket plane P1. In the illustrated embodiment, the first straight center line CL1 is defined at an axial center position of the first tooth tip 30 in the axial direction D2.

[0057] As in Fig. As can be seen in Figure 6, at least one second tooth 28 has a second axial chain engagement width W2, which is smaller than the inner connection space S1. At least one second tooth 28 has a second tooth tip 36, which extends parallel to the sprocket plane P1. Each of the multiple second teeth 28 has the second tooth tip 36, which extends parallel to the sprocket plane P1.

[0058] As in the Fig. 6 and Fig. As can be seen in Figure 7, the second tooth tip 36 includes a second leading edge 38 and a second trailing edge 40. The second leading edge 38 is positioned downstream of the second trailing edge 40 with respect to the drive direction of rotation D11.

[0059] As in Fig. As can be seen in Figure 6, a second straight centerline CL2 is defined to connect the second leading edge 38 with the second trailing edge 40. In the illustrated embodiment, the second straight centerline CL2 is parallel to the center sprocket plane P1.

[0060] As in the Fig. 4 and Fig. As can be seen in Figure 6, the sprocket body 20 has a first side 42 and a second side 44. The second side 44 is opposite to the first side 42 in an axial direction D2 parallel to the axis of rotation A1. In the illustrated embodiment, the sprocket plane P1 is a center sprocket plane defined to bisect the bicycle sprocket 12. More specifically, the center sprocket plane P1 is defined at an axial midpoint between the first side 42 and the second side 44 in the axial direction D2. As shown in Figure 6, the sprocket body 20 has a first side 42 and a second side 44. Fig. As can be seen in section 6, the second straight center line CL2 is defined at the center sprocket plane P1.

[0061] In the illustrated embodiment as shown in Fig. As can be seen in Figure 8, the first side 42 is closer to the bicycle frame F than the second side 44 in the axial direction D2, in a state where the bicycle chainring 12 is / is mounted on the bicycle frame F. However, the second side 44 can be closer to the bicycle frame F than the first side 42 in the axial direction D2, in a state where the bicycle chainring 12 is / is mounted on the bicycle frame F if required and / or desired.

[0062] As in Fig. As can be seen in Figure 4, the first leading edge 32 is positioned closer to the first side 42 than the first trailing edge 34 in the axial direction D2. The first trailing edge 34 is positioned closer to the second side 44 than the first leading edge 32. A first inclination angle AG1 is defined between the first straight center line CL and the center sprocket plane P1 on a downstream side of the drive direction of rotation D11. The first inclination angle AG1 is positioned closer to the first side 42 than to the second side 44. In the illustrated embodiment, the first inclination angle AG1 is an acute angle.

[0063] As in Fig. As can be seen in Figure 6, a second tilt angle AG2 is defined between the second straight centerline CL2 and the center sprocket plane P1 on the downstream side of the drive direction of rotation D11. The second tilt angle AG2 is defined at a position closer to the first side 42 than to the second side 44. In the illustrated embodiment, the second tilt angle AG2 is 0, since the second straight centerline CL2 is parallel to that of the center sprocket plane P1. Consequently, as in Fig. 4 and Fig. As can be seen in Figure 6, the second tilt angle AG2 is smaller than the first tilt angle AG1.

[0064] As in Fig. As shown in Figure 4, the first leading edge 32 projects at least partially from a tooth base 46 in an axial direction D2 into one direction from the first side 42 and the second side 44. The first leading edge 34 projects at least partially from the tooth base 46 in the axial direction D2 into the other direction from the first side 42 and the second side 44. In the illustrated embodiment, the leading edge 32 projects at least partially from the tooth base 46 in the axial direction D2 into the first side 42. The first leading edge 34 projects at least partially from the tooth base 46 in the axial direction D2 into the second side 44. The first leading edge 32 can project completely from the tooth base 46 in the axial direction D2 into the first side 42 if required and / or desired. The first trailing edge 34 can project completely from the tooth base 46 in the axial direction D2 into the second side 44 if required and / or desired.

[0065] As in the Fig. 2 and Fig. As shown in Figure 3, the bicycle chainring contains 12 tooth bases (46 teeth). Each of these tooth bases (46 teeth) is positioned between the first tooth (26 teeth) and the second tooth (28 teeth). As shown in the Fig. 5 and Fig. As can be seen in 7, the tooth bases 46 define a foot circle 48 of the bicycle chainring 12.

[0066] As in Fig. As shown in Figure 4, a first maximum leading distance L1, defined between the first leading edge 32 and the center sprocket plane P1 in the axial direction D2, is equal to a first maximum trailing distance L2, defined between the first trailing edge 34 and the center sprocket plane P1 in the axial direction D2. However, the first maximum leading distance L1 can differ from the first maximum trailing distance L2 if required and / or desired.

[0067] As in the Fig. 4 and Fig. As can be seen in Figure 9, at least one first tooth 26 has a leading recess 50 to prevent excessive contact of at least one first tooth 26 with an internal connecting plate C11 ( Fig. 4) to avoid the bicycle chain C. The leading recess 50 is at least partially provided on the first leading edge 32. In the illustrated embodiment, as shown in Fig. As can be seen in Figure 9, the leading recess 50 extends from the first leading edge 30 to the tooth base 46. The leading recess 50 can be omitted from the first tooth 26 if required and / or desired.

[0068] As in the Fig. 4 and Fig. As can be seen in Figure 10, at least one first tooth 26 has a trailing recess 52 to prevent excessive contact of at least one first tooth 26 with another internal connecting plate C12 ( Fig. 4) of the bicycle chain (C). The trailing recess 52 is provided at least partially on the first trailing edge 32. In the illustrated embodiment, as shown in Fig. As can be seen in Figure 10, the trailing recess 52 extends from the first trailing edge 32 to the tooth base 46. The trailing recess 52 can be omitted from the first tooth 26 if required and / or desired.

[0069] The bicycle chainring 12, as in Fig. As can be seen in Figure 4, the first tooth tip 30 does not extend parallel to the sprocket plane P1 perpendicular to the axis of rotation A1 when viewed from the radial direction of the bicycle sprocket 12. The at least one first tooth 26 has the first axial chain engagement width W1. The first axial chain engagement width W1 is larger than the inner connection space S1, which is defined between the pair of inner connection plates C1 of the bicycle chain C, and smaller than the outer connection space S2, which is defined between the pair of outer connection plates C2 of the bicycle chain C. The at least one second tooth 28 has the second axial chain engagement width B2, which is smaller than the inner connection space S1. Accordingly, it is possible to improve the functions for holding the bicycle chain 2 on the bicycle sprocket 12, while keeping the structure of the bicycle sprocket 12 simple. Second embodiment

[0070] A bicycle crank assembly 210 comprising a bicycle chainring 212 according to a second embodiment is described below with reference to the Fig. 11, Fig. 12, Fig. 13 to Fig. 14 described. The bicycle crank assembly 210 has the same configuration as the bicycle crank assembly 10 except for the first teeth 26. Consequently, the elements that have essentially the same function as those of the first embodiment are given the same reference numerals and are not described and / or illustrated in detail hereafter for the sake of brevity.

[0071] As in Fig. As can be seen in Figure 11, the bicycle chainring 212 includes a multitude of chain teeth 24, comprising at least one first tooth 262 and at least one second tooth 28. The at least one first tooth 226 comprises a multitude of first teeth 226. The at least one second tooth 28 comprises a multitude of second teeth 28.

[0072] As in the Fig. 12 and Fig. As can be seen in Figure 13, the first teeth 226 have essentially the same shape as the first teeth 26 according to the first embodiment. However, the first teeth 226 have a shape that is twisted in the opposite direction relative to the first teeth 26 according to the first embodiment.

[0073] As in Fig. As can be seen in Figure 14, the first tooth 226 has a shape such that the first tooth 26 ( Fig. 4) is inverted relative to the sprocket plane P1. For example, the first leading edge 232 is positioned closer to the second side 44 than the first trailing edge 234 in the axial direction D2. The first trailing edge 234 is positioned closer to the first side 42 than the first leading edge 232.

[0074] The first leading edge 234 projects at least partially from the tooth base 46 in the axial direction D2 into one of the first sides 42 and the second sides 44. More specifically, the first leading edge 234 projects at least partially from the tooth base 46 in the axial direction D2 into the first side 42. The first leading edge 232 projects at least partially from the tooth base 46 in the axial direction D2 into the other of the first side 42 and the second side 44. In the illustrated embodiment, at least the first leading edge 232 projects from the tooth base 46 in the axial direction D2 into the second side 44. However, the first leading edge 232 can project completely from the tooth base 46 in the axial direction D2 into the second side 44 if required or desired. Furthermore, the first leading edge 234 can project completely from the tooth base 46 in the axial direction D2 into the first side 42 if required and / or desired.

[0075] A first tilt angle AG21 is defined between the first straight center line CL1 and the center sprocket plane P1 on a downstream side of the drive direction of rotation D11. The first tilt angle AG21 is defined at a position closer to the first side 42 than to the second side 44. In the illustrated embodiment, the first tilt angle AG21 is an obtuse angle. The first tilt angle AG21 is greater than the first tilt angle AG1 ( Fig. 4).

[0076] With the bicycle chainring 212 it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment. Third embodiment

[0077] A bicycle crank assembly 310 comprising a bicycle chainring 312 according to a third embodiment is described with reference to the Fig. 15 and Fig. 16 described below. The bicycle crank assembly 310 has the same configuration as the bicycle crank assembly 10 except for the first teeth 26. Consequently, the elements that have essentially the same functions as those in the preceding embodiments are given the same reference numerals and are not described and / or illustrated again in detail herein for the sake of brevity.

[0078] As in Fig. As can be seen in Figure 15, in the bicycle chainring 312, the plurality of chainring teeth 24 includes at least one first tooth 326 and at least one second tooth 28. The at least one first tooth 326 includes a plurality of first teeth 326. The first teeth 326 have essentially the same shape as the first teeth 26 according to the first embodiment.

[0079] As in Fig. As can be seen in Figure 16, a first maximum leading distance L31, which is defined between the first leading edge 32 and the center sprocket plane P1 in the axial direction D2, differs from a first maximum trailing distance L32, which is defined between the first trailing edge 34 and the center sprocket plane P1 in the axial direction D2. In the illustrated embodiment, the first maximum leading distance L31 is greater than the first maximum trailing distance L32. As shown in Fig. As can be seen in 17, however, the first maximum leading distance L31 can be smaller than the first maximum trailing distance L32 if required and / or desired.

[0080] With the bicycle chainring 312 it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment. Fourth embodiment

[0081] A bicycle crank assembly 410 comprising a bicycle chainring 412 according to a fourth embodiment is now described below with reference to Fig. 18 described. The bicycle crank assembly 410 has essentially the same configuration as the bicycle crank assembly 10, except for the first teeth 26. Consequently, the elements that have essentially the same functions as those of the preceding embodiments are given the same reference numerals and are not described and / or illustrated in detail herein for the sake of brevity.

[0082] As in Fig. As can be seen in Figure 18, the bicycle chainring 410, with its multiple chainring teeth 24, includes at least one first tooth 426 and at least one second tooth 28. The at least one first tooth 426 comprises multiple first teeth 426. A first straight center line CL41 of the first tooth tip 30 of the first tooth 426 is perpendicular to the chainring plane P1. In other words, the first tooth tip 30 extends perpendicular to the chainring plane P1 and extends axially with respect to the axis of rotation A1. The first inclination angle AG41 is approximately 90 degrees.

[0083] With the bicycle chainring 412, it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment. Fifth embodiment

[0084] A bicycle crank assembly 510 comprising a bicycle chainring 512 according to a fifth embodiment is described below with reference to the Fig. 19 and Fig. 20 described. The bicycle crank assembly 510 has essentially the same configuration as the bicycle crank assembly 10 except for the first teeth 26. Consequently, the elements that have essentially the same function as those in the preceding embodiments are designated with the same reference numerals and are not described and / or illustrated in detail herein for the sake of brevity.

[0085] As in Fig. As can be seen in Figure 19, the bicycle chainring 512 includes a plurality of first teeth 26, at least one third tooth 550, and at least one fourth tooth 552. The plurality of first teeth 26 includes a plurality of third teeth 550 and a plurality of fourth teeth 525. The third teeth 550 and the fourth teeth 552 are arranged alternately in the circumferential direction D1.

[0086] As in Fig. As shown in Figure 20, a third tilt angle AG53 is defined between the first straight center line CL1 of the at least one third tooth 550 and the center sprocket plane P1 on a downstream side of the drive direction of rotation D11, and is defined at a position closer to the first side 42 than to the second side 44. A fourth tilt angle AG54 is defined between the first straight center line CL1 of the at least one fourth tooth 552 and the center sprocket plane P1 on the downstream side of the drive direction of rotation D11, and is defined at a position closer to the first side 42 than to the second side 44. The third tilt angle AG53 differs from the fourth tilt angle AG54. For example, the third tilt angle AG53 is larger than the fourth tilt angle AG54. However, the third tilt angle AG53 can be smaller than the fourth tilt angle AG54 if required and / or desired.

[0087] With the bicycle chainring 512, it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment. Sixth embodiment

[0088] A bicycle crank assembly 610 comprising a bicycle chainring 612 according to a sixth embodiment is described below with reference to the Fig. 21 and Fig. 22 described. The bicycle crank assembly 61 has the same configuration as the bicycle crank assembly 10 except for the second teeth 28. Consequently, the elements that have essentially the same function as those in the preceding embodiments are designated with the same reference numerals and are not described and / or illustrated again herein in detail for the sake of brevity.

[0089] As in Fig. As can be seen in Figure 21, in the bicycle chainring 612, the plurality of chainring teeth 24 includes at least one first tooth 26 and at least one second tooth 628. The at least one first tooth 26 is positioned adjacent to the at least one second tooth 628 without any tooth in between. In the illustrated embodiment, the at least one second tooth 628 includes a plurality of second teeth 628.

[0090] As in Fig. As can be seen in Figure 22, the plurality of second teeth 628 has a second tooth tip 636 with a second leading edge 638 and a second trailing edge 640. The second leading edge 638 is positioned downstream of the second trailing edge 640 with respect to the drive direction D11. A second straight center line CL62 is defined to connect the second leading edge 638 with the second trailing edge 640 and is non-parallel to the sprocket plane P1. The second straight center line CL62 is inclined with respect to the sprocket plane P1.

[0091] A second tilt angle AG62 is defined between the second straight center line CL62 and the center sprocket plane P1 on the upstream side of the drive direction of rotation D11 and is defined at a position closer to the first side 42 than to the second side 44. In the illustrated embodiment, the second tilt angle AG62 is equal to the first tilt angle AG1 ( Fig. 4) However, the second tilt angle AG62 can differ from the first tilt angle AG1 if required and / or desired. As in the Fig. 21 and Fig. As can be seen in Figure 22, the maximum longitudinal length ML62 of the second tooth tip 636 is smaller than the maximum longitudinal length ML61 of the first tooth tip 30 when viewed from a radial direction of the bicycle chainring 612, such that the second teeth 628 each have a second axial chain engagement width W62 which is smaller than the first axial chain engagement width W1, and such that the second chain engagement width W62 is smaller than the inner connection space S1 which is defined between a pair of inner connection plates C1 of the bicycle chain C, whereas the first chain engagement width W1 is larger than the inner connection space S1 and smaller than the outer connection space S2 which is defined between the pair of outer connection plates C2 of the bicycle chain C.

[0092] With the bicycle chainring 612 it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment. Seventh embodiment

[0093] A bicycle crank assembly 710 comprising a bicycle chainring 712 according to a seventh embodiment is described below with reference to Fig. 23 described. The bicycle crank assembly 710 has the same configuration as the bicycle crank assembly 10 except for the first page 42 and the second page 44. Consequently, the elements that have essentially the same function as those in the preceding embodiments are given the same reference numerals and are not described and / or illustrated again in detail herein for the sake of brevity.

[0094] As in Fig. As can be seen in Figure 23, with the bicycle chainring 712, the second side 44 is closer to the bicycle frame F than the first side 42 in the axial direction D2, in a state in which the bicycle chainring 12 is / is mounted on the bicycle frame F.

[0095] With the bicycle chainring 712 it is possible to achieve essentially the same advantageous effects as with the bicycle chainring 12 according to the first embodiment.

[0096] It will be apparent to the person skilled in the art in the field of bicycles from the present disclosure that the designs according to the above embodiments can be combined with one another, at least partially. Fig. Figure 24 shows exemplary arrangements of the first and second teeth. Fig.24. The dashed lines indicate the first and second tooth tips. Exemplary arrangement EA1 corresponds to the first and third embodiments. Exemplary arrangement EA2 corresponds to the second embodiment. Exemplary arrangement EA3 corresponds to the fourth embodiment. Exemplary arrangement EA4 corresponds to the fifth embodiment. Exemplary arrangement EA5 corresponds to the sixth embodiment. Each of the exemplary arrangements EA6 to EA9 corresponds to a combination of at least two designs from the preceding embodiments.

[0097] In the present application, the terms "attached" or "fastening," as used herein, may include configurations in which one element is directly attached to another by fastening the element directly to the other element; configurations in which the element is indirectly attached to the other element via an intermediate element; and configurations in which one element is integral with the other element, i.e., one element is an essential part of the other element. This concept may also be applied to similar meanings such as "connected," "coupled," "mounted," "glued," "fixed," and their derivatives.

[0098] The terms "comprehensive" and its derivatives, as used herein, can be understood as open terms that specify the presence of the mentioned features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unmentioned features, elements, components, groups, integers, and / or steps. The foregoing also applies to words with similar meanings, such as "exhibiting," "containing," and their derivatives.

[0099] The terms “link”, “section”, “section”, “part”, “element”, “body” and “structure”, when used in the singular, can have the plural meaning of a single part or a multitude of parts.

[0100] The ordinal numbers, such as "first" and "second," as cited in the present application, are merely descriptive and have no further meaning, such as indicating a specific order or anything similar. Furthermore, the term "first element," for example, does not in itself imply the existence of a "second element," and the term "second element" does not in itself imply the existence of a "first element."

[0101] The term “a pair of”, as used herein, includes configurations in which the pair of elements have different shapes and structures relative to each other, and additionally configurations in which the pair of elements have the same shapes or structures relative to each other.

[0102] Finally, the magnitude terms such as "for example", "essentially", "by" and "approximately", as used herein, represent a reasonable amount of deviation of the modified term so that the final result is not significantly altered.

[0103] Naturally, different modifications and variants of the present invention are possible in light of the foregoing teaching. It should therefore be understood that, within the scope of the appended claims, the present invention may be exercised differently than specifically described herein.

Claims

[1] Bicycle chain wheel (12) comprising: a sprocket body (20) comprising a rotational axis (A1), a first side (42) and a second side (44) opposite the first side (42) in an axial direction (D2) parallel to the rotational axis (A1); and A chain engagement structure (22) which is / will be arranged on an outer periphery of the sprocket body (20), wherein the chain engagement structure (22) includes a plurality of sprocket teeth (24) which extend radially outwards from the outer periphery of the sprocket body (20), wherein the plurality of sprocket teeth (24) includes at least one first tooth (26) and at least one second tooth (28), wherein the at least one first tooth (26) has a first tooth tip (30) which extends non-parallel to a sprocket plane (P1) perpendicular to the axis of rotation (A1) when viewed from a radial direction of the bicycle sprocket (12), wherein the at least one first tooth (26) has a first axial chain engagement width (W1) which is larger than an inner connection space (S1) which is defined between a pair of inner connection plates of a bicycle chain (C) and is smaller than an outer connection space (S2),which is defined between a pair of outer connecting plates of the bicycle chain (C), and wherein at least one second tooth (28) has a second axial chain engagement width (W2) that is smaller than the inner connecting space (S1). [2] Bicycle chain wheel (12) according to claim 1, wherein the at least one first tooth (26) includes a plurality of first teeth and / or the at least one second tooth (28) includes a plurality of second teeth. [3] Bicycle chain wheel (12) according to claim 1 or 2, wherein the total number of the plurality of chain wheel teeth (24) is an even number. [4] Bicycle chain wheel (12) according to one of claims 1 to 3, wherein the total number of the first tooth(s) (26) is equal to the total number of the second tooth(s) (28) and / or the second teeth are arranged alternately between the first teeth. [5] Bicycle chain wheel (12) according to one of claims 1 to 4, wherein the first tooth tip (30) is inclined in relation to the chain wheel plane (P1). [6] Bicycle chainring (12) according to any one of claims 1 to 5, wherein the first tooth tip (30) has a first leading edge (32) and a first trailing edge (34), wherein the first leading edge (32) is / is positioned downstream with respect to the first trailing edge (34) in a drive rotation direction (D11) of the bicycle chainring (12) and a first straight center line (CL1) is defined to connect the first leading edge (32) with the first trailing edge (34) and is not parallel to the chainring plane (P1). [7] Bicycle chain wheel (12) according to claim 6, wherein the first teeth (26) include at least a third tooth (550) and at least a fourth tooth (552); a third inclination angle (AG53) is defined between the first straight center line (CL1) of the at least one third tooth (550) and the center sprocket plane (P1) of a downstream side of the drive direction of rotation (D11) and is defined in a position closer to the first side (42) than to the second side (44); a fourth inclination angle (AG54) is defined between the first straight center line (Cl1) of the at least one fourth tooth (552) and the center sprocket plane (P1) of the downstream side of the drive direction of rotation (D11) and is defined in a position closer to the first side (42) than to the second side (44) and where the third tilt angle (AG53) differs from the fourth tilt angle (AG54). [8] Bicycle chainring (12) according to claim 6 or 7, wherein the first tooth(s) (26) has / have a leading recess (50) to avoid excessive contact of the first tooth (26) with an inner connecting plate of the bicycle chain (C), wherein the leading recess (50) is / is provided at least partially on the first leading edge (32) and a trailing recess (52) to avoid excessive contact of the first tooth (26) with a further inner connecting plate of the bicycle chain (C), wherein the trailing recess (52) is / is provided at least partially on the first trailing edge (34). [9] Bicycle chain wheel (12) according to one of claims 6 to 8, wherein the first leading edge (32) is / will be positioned closer to the first side (42) than the first trailing edge (34) in the axial direction (D2) and the first trailing edge (34) is / will be positioned closer to the second side (44) than the first leading edge (32). [10] Bicycle chain wheel (12) according to one of claims 6 to 8, wherein the first leading edge is / will be positioned closer to the second side (44) than the first trailing edge (34) in the axial direction (D2) and the first trailing edge (34) is / will be positioned closer to the first side (42) than the first leading edge (32). [11] Bicycle chain wheel (12) according to one of claims 6 to 10, wherein the first leading edge (32) projects at least partially from a tooth base (46) in the axial direction (D2) into a space between the first side (42) and the second side (44). [12] Bicycle chain wheel (12) according to claim 11, wherein the first trailing edge (34) projects at least partially from the tooth base (46) in the axial direction (D2) into the other from the first side (42) and the second side (44). [13] Bicycle chain wheel (12) according to one of claims 6 to 11, wherein the first trailing edge (34) projects at least partially from the tooth base (46) in the axial direction (D2) into a space between the first side (42) and the second side (44). [14] Bicycle chain wheel (12) according to any one of claims 6 to 13, wherein the first straight center line (CL1) is either inclined or perpendicular to the chain wheel plane (P1). [15] Bicycle chainring (12) according to any one of claims 6 to 14, wherein the chainring plane (P1) is a center chainring plane (P1) defined to cut the bicycle chainring (12), in particular to halve it. [16] Bicycle chainring (12) according to claim 15, wherein a first inclination angle (AG1) is defined between the first straight center line (CL1) and the center chainring plane (P1) in a downstream side of the drive direction of rotation (D11) and is defined at a position closer to the first side (42) than to the second side (44); a second inclination angle (AG2) is defined between the second straight center line (CL2) and the center chainring plane (P1) in a downstream side of the drive direction of rotation (D11) and is defined at a position closer to the first side (42) than to the second side (44) and wherein the second inclination angle (AG2) is either equal to or less than the first inclination angle (AG1). [17] Bicycle chainring (12) according to claim 15 or 16, wherein the second tooth(s) (28) each have a second tooth tip (36), the second tooth tip (36) comprising a second leading edge (38) and a second trailing edge (40), the second leading edge (38) being positioned downstream of the second trailing edge (40) with respect to the direction of drive rotation (D11), and a second straight center line (CL2) being defined to connect the second leading edge (38) with the second trailing edge (40) being either parallel or non-parallel to the center chainring plane (P1). [18] Bicycle chainring (12) according to one of claims 15 to 17, wherein a first maximum leading distance (L31) defined between the first leading edge (32) and the center chainring plane (P1) in the axial direction (D2) is either equal to or different from a first maximum trailing distance (L32) defined between the first trailing edge (34) and the center chainring plane (P1) in the axial direction (D2). [19] Bicycle chain wheel (12) according to claim 18, wherein the first maximum leading distance (L31) is either greater or less than the first maximum trailing distance (L32). [20] Bicycle chainring (12) according to one of claims 1 to 19, wherein the second tooth(s) (28) each have a second tooth tip (36) extending parallel to the chainring plane (P1), in particular a maximum longitudinal length (ML62) of the second tooth tip is smaller than a maximum longitudinal length (ML61) of the first tooth tip (30) when viewed from a radial direction of the bicycle chainring. [21] Bicycle chainring (12) according to any one of claims 1 to 20, wherein either the first side (42) or the second side (44) is closer to a bicycle frame (F) than the other side (42; 44) in the axial direction (D2), in a state in which the bicycle chainring (12) is / is mounted on the bicycle frame (F). [22] Bicycle chain wheel (12) according to any one of claims 1 to 21, further comprising a crank arm attachment section (18). [23] Bicycle chain wheel (12) according to one of claims 1 to 22, in which the at least one first tooth (26) is adjacent to the at least one second tooth (28) without a tooth being positioned between them. [24] Bicycle crank assembly (10) comprising: the bicycle chainring (12) according to one of claims 1 to 23. [25] Bicycle crank assembly (10) according to claim 24, wherein the bicycle chain wheel (12) is a single chain wheel for the bicycle crank assembly (10).

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