bicycle chainring

Abstract

bicycle chainring (10) comprising: including sprocket teeth (12) at least one first tooth (14) configured to engage with outer connecting plates (1d) of a bicycle chain (1) and having a first radial tooth height (H1), wherein the at least one first tooth (14) has a first axial chain engagement width (W1) which is smaller than a first distance (L1) defined between opposing outer connecting plates (1d) of the bicycle chain (1) and which is larger than a second distance (L2) defined between opposing inner connecting plates (1c) of the bicycle chain (1), wherein the at least one first tooth (14) includes a chamfered section (222) adjacent to a first tooth base (14a) of the at least one first tooth (14), the chamfered section (222) extending from the first tooth base (14a) to an end of the at least one first tooth (14), and at least a second tooth (16) adjacent to the first tooth (14), wherein the at least one second tooth (16) is designed to engage with internal connecting plates (1c) of the bicycle chain (1), wherein the at least one second tooth (16) has a second radial tooth height (H2), wherein the at least one second tooth (16) has a second axial chain engagement width (W2) which is less than the second distance (L2), and wherein the first radial tooth height (H1) is greater than the second radial tooth height (H2).

Description

[0001] This application is a divisional application of parent application DE 10 2015 006 582.3, filed on May 20, 2015, and claims priority from US patent application No. 14 / 283,165, filed on May 20, 2014. The entire disclosure of US patent application No. 14 / 283,165 is hereby incorporated by reference.

[0002] The present invention relates to a bicycle sprocket.

[0003] Cycling has become an increasingly popular form of recreation as well as 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 continually improved the various components of the bicycle. One component that has recently been redesigned is the bicycle sprocket.

[0004] Most bicycles have a drivetrain that uses the bicycle sprocket to transmit pedaling motion from the rider to a bicycle wheel through a bicycle chain. A front sprocket and a rear sprocket are known as the bicycle sprocket. The bicycle sprocket typically includes a plurality of teeth to engage / engage the bicycle chain. Bicycle sprockets are known from German laid-open applications DE 10 2012 023 819 A1, DE 10 2006 039 333 A1, DE 10 2010 023 882 A1, DE 10 2006 057 168 A1, and DE 20 2010 002 653 U1, as well as from US patent application US 2015 / 0 285 364 A1.

[0005] It is an object of the present invention to provide an improved bicycle sprocket with an improved chain retention function. This object is achieved by the subject matter of main claim 1, with further advantageous embodiments being described in the subclaims.

[0006] A more complete appreciation of the invention and many of the attendant advantages thereof will be more readily apparent as the same become better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: Fig. 1 is an elevational view of a bicycle sprocket according to a first embodiment; Fig. 2 an enlarged elevation view of the bicycle sprocket illustrated in Fig. 1 is; Fig. 3 a partial perspective view of the bicycle sprocket illustrated in Fig. 1 is; Fig. 4 a cross-sectional view of the bicycle sprocket along the line IV-IV of Fig. 2 is; Fig. 5 a cross-sectional view of the bicycle sprocket along the line VV of Fig. 2 is; Fig. 6 a cross-sectional view of the bicycle sprocket along the line VI-VI of Fig. 2 is; Fig. 7 an enlarged elevational view of the bicycle sprocket illustrated in Fig. 1 is for explaining the positional relationship between the bicycle sprocket and a bicycle chain; Fig. 8 is an enlarged elevational view of a bicycle sprocket according to a second embodiment; Fig. 9 a cross-sectional view of the bicycle sprocket illustrated in Fig. 8; Fig. 10 is an enlarged elevational view of the bicycle sprocket according to a third embodiment; Fig. 11 a cross-sectional view of the bicycle sprocket along the line XI-XI of Fig. 10 is; Fig. 12 a cross-sectional view of the bicycle sprocket along the line XII-XII of Fig. 10; Fig. 13 is a cross-sectional view of the bicycle sprocket according to a fourth embodiment; Fig. 14 is an enlarged elevational view of a bicycle sprocket according to a fifth embodiment; Fig. 15 is an enlarged elevational view of a bicycle sprocket according to a sixth embodiment; Fig. 16 is an enlarged elevational view of the bicycle sprocket according to the sixth embodiment; Fig. 17 is an elevational view of a bicycle sprocket according to a seventh embodiment; Fig. 18 is an enlarged elevational view of a bicycle sprocket according to an eighth embodiment; Fig. 19 a cross-sectional view of the bicycle sprocket along the line XIX-XIX of Fig. 18 is; Fig. 20 a cross-sectional view of the bicycle sprocket along the line XX-XX of Fig. 18 is; Fig. 21 is an enlarged elevational view of the bicycle sprocket according to a ninth embodiment; Fig. 22 a cross-sectional view of the bicycle sprocket along the line XXII-XXIII of Fig. 21 is; Fig. 23 a cross-sectional view of the bicycle sprocket along the line XXIII-XXIII of Fig. 21 is; Fig. 24 is an elevational view of a bicycle sprocket according to a tenth embodiment; and Fig. 25 is an enlarged elevational view of a bicycle sprocket according to an eleventh embodiment for explaining the positional relationship between the bicycle sprocket and a bicycle chain.

[0007] The embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the different drawings.

[0008] Firstly, referring to Fig. 1, a bicycle sprocket 10 according to a first embodiment is configured to engage / engage a bicycle chain 1. The bicycle sprocket 10 is rotatable about a rotational center axis A. In the illustrated embodiment, the bicycle sprocket 10 is a front sprocket configured to be provided with a crank drive (right crank drive) of a bicycle. However, the structures of the bicycle sprocket 10 can be applied to a rear sprocket.

[0009] The bicycle sprocket 10 is configured to be fixed to crank connecting arms 2a of a sprocket mounting member 2 by bolts (not shown). The sprocket mounting member 2 is fixed to a crank arm 4 so as to be rotatable integrally with the crank arm 4 about the rotational center axis A. The sprocket mounting member 2 may also be provided integrally with the crank arms 4 as a single unit member. The sprocket 10 is configured to be rotatable integrally with the sprocket mounting member 2 and the crank arm 4 about the rotational center axis A. The sprocket 10 is configured to be rotated around the rotational center axis A in a rotational drive direction D11 during pedaling or riding. The rotational drive direction D11 is defined along a circumferential direction D1 of the bicycle sprocket 10. A direction D12 is defined along the circumferential direction D1. The direction D12 is opposite to the rotary drive direction D11.

[0010] As in Fig. 1, the bicycle sprocket 10 includes sprocket teeth 12. The sprocket teeth 12 include at least one first tooth 14 and at least one second tooth 16. In the illustrated embodiment, the sprocket teeth 12 include a plurality of first teeth 14 as the at least one first tooth 14 and a plurality of second teeth 16 as the at least one second tooth 16. The at least one first tooth 14 and the at least one tooth 16 are alternately arranged in the circumferential direction D1 of the bicycle sprocket 10. In the illustrated embodiment, the first teeth 14 and the second teeth are alternately arranged in the circumferential direction D1. The sprocket teeth 12 may include at least one first tooth 14 (e.g., a first tooth 14) and at least one second tooth 16 (e.g., a second tooth 16) if needed and / or desired.In addition, the sprocket teeth 12 may include teeth having a different shape from each of the first tooth 14 and the second tooth 16.

[0011] The bicycle sprocket 10 further includes a sprocket body 18 having an annular shape. The sprocket teeth 12 protrude radially outward from the sprocket body 18. The at least one first tooth 14 and the at least one second tooth 16 are alternately arranged on an entire circumference of the sprocket body 18 in the circumferential direction D1. The sprocket body 18 is configured to be fastened to the crank connecting arms 2a of the sprocket mounting member 2 by bolts (not shown). In the illustrated embodiment, the sprocket teeth 12 and the sprocket body 18 comprise a metallic material such as aluminum, steel, iron, and titanium, respectively. The sprocket teeth 12 are provided integrally with the sprocket body 18 as a single unitary member. However, the sprocket teeth 12 may be provided separately from the sprocket body 18.

[0012] As in Fig. 2, the at least one second tooth 16 is adjacent to the first tooth 14 and is arranged on a downstream side in the rotational drive direction D11 of the bicycle sprocket 10. The sprocket teeth 12 include tooth bottoms 12a, which define a base circle RC of the bicycle sprocket 10. As shown in the Fig. 2 and Fig. 3, the at least one first tooth 14 has a first radial tooth height H1. The at least one second tooth 16 has a second radial tooth height H2. The first radial tooth height H1 is greater than the second radial tooth height H2. In the illustrated embodiment, the first radial tooth height H1 is defined between the base circle RC and a radially outer end of the first tooth 14. The second radial tooth height H2 is defined between the base circle RC and a radially outer end of the second tooth 16.

[0013] As in Fig. As can be seen in Figure 4, the at least one first tooth 14 is configured to engage with outer link plates 1d of the bicycle chain 1. The at least one first tooth 14 has a first axial chain engagement width W1 that is less than a first distance L1 defined between the opposing outer link plates 1d of the bicycle chain 1 and greater than a second distance L2 defined between the opposing inner link plates 1c of the bicycle chain 1. The at least one second tooth 16 is configured to engage with inner link plates 1c of the bicycle chain 1. The at least one second tooth 16 has a second axial chain engagement width W2 that is less than the second distance L2.Preferably, the first axial chain engagement width W1 is defined such that the at least one first tooth 14 is / comes into engagement with the outer connecting plate 1d and the second axial chain engagement width W2 is defined such that the at least one second tooth 16 is / comes into engagement with the inner connecting plates 1c.

[0014] As in Fig. As can be seen in Figure 4, the opposed outer connecting plates 1d include opposed inner surfaces 1f defining an axial space AS1 in which the first tooth 14 is disposed. The opposed inner connecting plates 1c include opposed inner surfaces 1e defining an axial space AS2 in which the second tooth 16 is disposed. The first distance L1 is an axial distance between the opposed inner surfaces 1f of the opposed outer connecting plates 1d in a direction D2 parallel to the center axes CA of the pins 1b that rotatably support the rollers 1a. The second distance L2 is an axial distance between the opposed inner surfaces 1e of the opposed inner connecting plates 1c in the direction D2 parallel to the center axes CA of the pins 1b.

[0015] As in Fig. As can be seen in Figure 5, the first tooth 14 has a first chain engagement surface 14b and a second chain engagement surface 14c. The first chain engagement surface 14b and the second chain engagement surface 14c face in an axial direction D3 parallel to the rotational axis A of the bicycle sprocket 10. The first chain engagement surface 14b and the second chain engagement surface 14c are contactable with the opposite inner surfaces 1f of the outer link plates 1d, respectively. For example, the first axial chain engagement width W1 is a maximum axial width defined between the first chain engagement surface 14b and the second chain engagement surface 14c in the axial direction D3. In a state where the bicycle chain 1 engages with the bicycle sprocket 10, the axial direction D3 coincides with the direction D2 defined with respect to the bicycle chain 1.

[0016] As in Fig. As can be seen in Figure 6, the second tooth 16 has a third chain engagement surface 16b and a fourth chain engagement surface 16c. The third chain engagement surface 16b and a fourth chain engagement surface 16c face each other in the axial direction D3. The third chain engagement surface 16b and the fourth chain engagement surface 16c are contactable with the opposite inner surfaces 1f of the inner link plates 1c, respectively. For example, the second axial chain engagement width W2 is a maximum axial width defined between the third chain engagement surface 16b and the fourth chain engagement surface 16c in the axial direction D3.

[0017] In the bicycle sprocket 10, as in Fig. As can be seen in Figure 4, the at least one first tooth 14 has the first axial chain engagement width W1, which is smaller than the first distance L1 defined between the opposing outer connecting plates of the bicycle chain 1 and which is larger than the second distance L2 defined between the opposing inner connecting plates of the bicycle chain 1. This improves the holding function of the bicycle sprocket 10 for the bicycle chain 1.

[0018] Furthermore, since the contact between the second tooth 16 and the bicycle chain 1 reduces the contact pressure between the first tooth 14 and the bicycle chain 1, it is possible to reduce the wear of the first tooth 14 compared to a comparable bicycle sprocket including only the first tooth 14 or the second tooth 16. Accordingly, it is possible to maintain the service life of the bicycle sprocket 10 while improving the holding function of the bicycle sprocket 10 for the bicycle chain 1.

[0019] A bicycle sprocket 210 according to a second embodiment is described with reference to the Fig. 8 and Fig. 9 below. The bicycle sprocket 210 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Consequently, the elements having substantially the same functions as those of the first embodiment are given the same reference numerals and will not be described in detail again for the sake of brevity. Fig. 8 and Fig. 9, the at least one first tooth 14 includes a chamfered portion configured to reduce the interaction between the at least one first tooth and one of the inner connecting plates of the bicycle chain 1. In the illustrated embodiment, the first tooth 14 includes chamfered portions 222 configured to reduce the interaction between one of the inner connecting plates 1c ( Fig. 9) of the bicycle chain 1 and the first tooth 14 in a state where the first tooth 14 is engaged with the bicycle chain 1. More specifically, each of the bicycle sprocket teeth 12 includes chamfered portions 222 configured to facilitate the interaction between each of the sprocket teeth 12 and one of the inner connecting plates 1c ( Fig. 9) of the bicycle chain 1 in a state where the sprocket teeth 12 are engaged with the bicycle chain 1. As shown in Fig. 8, the chamfered portion 222 of the first tooth 14 is adjacent to the tooth bottom 12a of the first tooth 14. In the illustrated embodiment, the chamfered portion 222 of the first tooth 14 is adjacent to a first tooth bottom 14a of the first tooth 14. The chamfered portion 222 of the first tooth 14 preferably extends from the first tooth bottom 14a to one end of the first tooth 14.

[0020] In the bicycle sprocket 210, the chamfered portion 222 can reduce the wear of the first tooth 14 in addition to the advantageous effects achieved by the bicycle sprocket 10 in the first embodiment.

[0021] A bicycle sprocket 310 according to a third embodiment will be described below with reference to the Fig. 10 to 12. The bicycle sprocket 310 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Consequently, the elements having substantially the same function as those of the first embodiment are given the same reference numerals and will not be described in detail again for the sake of brevity. Fig. As can be seen in Figures 10 to 12, the bicycle sprocket 10 further comprises at least one additional tooth having an axial chain engagement width that is less than the second distance L1 defined between the opposing inner connecting plates 1c of the bicycle chain 1. Each of the at least one additional tooth is arranged adjacent to the at least one first tooth 14 such that the bicycle chain 1 is shifted between the bicycle sprocket 10 and an additional bicycle sprocket in a region in which the at least one additional tooth is positioned.

[0022] In the illustrated embodiment, the bicycle sprocket 310 further comprises an additional tooth 317. The additional tooth 317 is arranged between the adjacent two of the first teeth 14, such that the bicycle chain 1 is arranged between the bicycle sprocket 10 and an additional bicycle sprocket 315 ( Fig. 12) is shifted in a region in which the additional tooth 317 is positioned. The additional bicycle sprocket 315 is rotatable integrally with the bicycle sprocket 310. The structures of the bicycle sprocket 310 can be applied to the additional bicycle sprocket 315 if needed and / or desired.

[0023] As in Fig. As can be seen in Figure 10, the additional tooth 317 has a third radial tooth height H3. The third radial tooth height H3 is greater than the second radial tooth height H2 of the second tooth 16. The third radial tooth height H3 is substantially equal to the first radial tooth height H1 of the first tooth 14.

[0024] As in Fig. As can be seen in Figure 11, the additional tooth 317 has an axial chain engagement width W3 that is less than the second distance L2. The axial chain engagement width W3 is less than the first axial chain engagement width W1 of the first tooth 14. The axial chain engagement width W3 is substantially equal to the second axial chain engagement width W2 of the second tooth 16.

[0025] As in Fig. As can be seen in Figure 12, the additional tooth 317 has a first chain engagement surface 317b and a second chain engagement surface 317c. The first chain engagement surface 317b and the second chain engagement surface 317c face each other in the axial direction D3. The first chain engagement surface 317b and the second chain engagement surface 317c are contactable with the opposite inner surfaces 1e of the inner link plates 1c, respectively. For example, the axial chain engagement width W3 is a maximum axial width defined between the first chain engagement surface 317b and the second chain engagement surface 317c in the axial direction D3, which is parallel to the rotational axis A of the bicycle sprocket 310.

[0026] As in Fig. 12, the bicycle sprocket 310 may further comprise a spike pin 352 which is designed to push the bicycle chain 1 toward the sprocket teeth 12 ( Fig. 10) during shifting. The bicycle sprocket 310 may include a plurality of stud pins, such as the stud pin 352. The stud pin 352 is made of a metallic material and is a separate member from the sprocket teeth 12 and the sprocket body 18. However, the stud pin 352 may be provided integrally with the sprocket teeth 12 and the sprocket body 18.

[0027] As described above, the bicycle sprocket 10 according to the first embodiment can be applied to a bicycle sprocket assembly for gear changing.

[0028] A bicycle sprocket 410 according to a fourth embodiment will be described below with reference to Fig. 13. The bicycle sprocket 410 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0029] As in Fig. As can be seen from Figure 13, each of the sprocket teeth 12 has a multi-layered structure with different materials. Each of the sprocket teeth 12 includes a first sprocket layer 430, a second sprocket layer 432, and a third sprocket layer 434. For example, the first sprocket layer 430 is made of a first layer material comprising steel or iron. The second sprocket layer 432 may be made of a second layer material comprising a plastic or resin material. The third sprocket layer is made of a third layer material comprising steel. The second sprocket layer 432 is provided between the first sprocket layer 430 and the third sprocket layer 434. For example, the first sprocket layer 430 and the third sprocket layer 434 are joined to the second sprocket layer 432 by means of an integral molding process.

[0030] The materials of the multi-layered structure of the sprocket teeth 12 are not limited to the above embodiment. For example, the second sprocket layer 432 can be made of a second layer material comprising aluminum. In such an embodiment, the second sprocket layer 432 is bonded to the first sprocket layer 430 and the third sprocket layer 434 using diffusion bonding or material bonding with adhesives.

[0031] In the bicycle sprocket 410, the multi-layer structure can save weight of the sprocket teeth 12 in addition to the advantageous effects achieved by the sprocket 10 according to the first embodiment.

[0032] A bicycle sprocket 510 according to a fifth embodiment will be described below with reference to Fig. 14. The bicycle sprocket 510 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0033] As in Fig. 14, each of the sprocket teeth 12 includes the tooth bottom 12a, which defines the base circle RC of the bicycle sprocket 510. At least one of the sprocket teeth 12 includes a closed opening provided at least partially radially outward from the base circle RC. In the illustrated embodiment, each of the first teeth 14 includes a closed opening 513 provided at least partially radially outward from the base circle RC. Each of the second teeth 16 includes a closed opening 515 provided entirely radially outward from the base circle RC. The closed opening, such as closed openings 513 and 515, may be provided in at least one of the sprocket teeth 12 if needed and / or desired. The closed opening 513 may be provided entirely radially outward from the base circle RC if needed and / or desired.Furthermore, the closed opening 515 may be provided at least partially radially outward from the base circle RC if needed and / or desired. One of the closed openings 513 and 515 may be omitted from the bicycle sprocket 510 if needed and / or desired.

[0034] In the bicycle sprocket 510, the closed openings 513 and 515 can save weight from the sprocket teeth 12 in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0035] A bicycle sprocket 610 according to a sixth embodiment will be described below with reference to the Fig. 15 and Fig. 16. The bicycle sprocket 610 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Consequently, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity. Fig. 15 and Fig. 16, at least one of the sprocket teeth 12 includes a cutout configured to increase the flexibility of the at least one of the sprocket teeth 12. In the illustrated embodiment, as shown in Fig. As can be seen in Figure 15, each of the first teeth 14 includes a cutout 617 configured to increase the flexibility of each of the first teeth 14. The cutout 617 extends in the circumferential direction D1. More specifically, the cutout 617 extends in the rotational drive direction D11 from one of the tooth bottoms 12a toward the other of the tooth bottoms 12a in the first tooth 14.

[0036] Similar to Fig. 16, each of the second teeth 16 includes a cutout 619 configured to increase the flexibility of each of the second teeth 16. The cutout 619 extends in the circumferential direction D1. More specifically, the cutout 619 extends in the rotational drive direction D11 from one of the tooth bottoms 12a toward the other of the tooth bottoms 12a in the second tooth 16. The cutout, such as the cutouts 617 and 619, may be provided in at least one of the sprocket teeth 12 if needed and / or desired. The shapes of the cutouts 617 and 619 are not limited to the illustrated embodiment.

[0037] In the bicycle sprocket 610, the cutout 617 allows the first tooth 14 to absorb shock caused by the first tooth 14 and the bicycle chain 1, thereby making it possible to improve the wear resistance of the first tooth in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment. Similarly, the cutout 619 allows the second tooth 16 to absorb shock caused by the second tooth 16 and the bicycle chain 1, thereby making it possible to improve the wear resistance of the second tooth 16 in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0038] A bicycle sprocket 710 according to a seventh embodiment will be described below with reference to Fig. 17. The bicycle sprocket 710 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12 and the sprocket body 18. Consequently, the elements that have substantially the same function as in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity. As shown in Fig. 17, the bicycle sprocket 710 includes sprocket teeth 712. The sprocket teeth 712 include at least one first tooth 714 and at least one second tooth 716. In the illustrated embodiment, the sprocket teeth 712 include a plurality of first teeth 714 as the at least one first tooth 714 and a plurality of second teeth 716 as the at least one second tooth 716. The at least one first tooth 714 and the at least one second tooth 716 are arranged alternately in the circumferential direction D1 of the bicycle sprocket 10.

[0039] The bicycle sprocket 710 further includes a sprocket body 718 having an annular shape. The sprocket teeth 712 are separate members and are spaced apart from each other in the circumferential direction D1 of the bicycle sprocket 710. The sprocket body 718 is configured to be secured to the crank connecting arms 2a of the sprocket mounting member 2 by bolts (not shown).

[0040] Each of the sprocket teeth 712 includes a base portion and a tooth portion. In the illustrated embodiment, the tooth portion 714 includes a base portion 714a and a tooth portion 714b. The base portion 714a is implanted into the sprocket body 718. The tooth portion 714b projects radially outward from the base portion 714a. Similarly, the second tooth 716 includes a base portion 716a and a tooth portion 716b. The base portion 716a is implanted into the sprocket body 718. The tooth portion 716b projects radially outward from the base portion 716a. Each of the sprocket teeth 712 is made from a first material comprising a metallic material, e.g., which may be selected from a group comprising aluminum, titanium, or steel. The sprocket body 718 is made from a second material that is lighter than the first material.For example, such a second material may be selected from a group comprising aluminum, titanium, and a plastic. The first teeth 714 and the second teeth 716 are at least partially embedded in the sprocket body 718 by integral molding processes, such as insert molding processes.

[0041] In the bicycle sprocket 710, since the sprocket body 718 is made of a second material including a resin material, it is possible to save weight of the bicycle sprocket 710 in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0042] A bicycle sprocket 810 according to an eighth embodiment will be described below with reference to the Fig. 18 to 20. The bicycle sprocket 810 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0043] As in Fig. As can be seen in Figure 18, the sprocket teeth 12 are evenly spaced from each other in the circumferential direction D1 of the bicycle sprocket 810. Each of the sprocket teeth 12 has a centerline extending from the rotational axis A of the bicycle sprocket 810. Each of the sprocket teeth 12 has a symmetrical shape with respect to the centerline.

[0044] In the illustrated embodiment, each of the first teeth 14 has a centerline CL1 extending from the rotational axis A of the bicycle sprocket 810. Each of the first teeth 14 has a symmetrical shape with respect to the centerline CL1. More specifically, each of the first teeth 14 has a symmetrical shape with respect to the centerline CL1 when viewed from a direction of the rotational axis A.

[0045] As in Fig. 19, the center line CL1 is perpendicular to the rotation axis A. Each of the first teeth 14 has a symmetrical shape with respect to the center line CL1 when viewed from the circumferential direction D1 of the bicycle sprocket 810.

[0046] Similar to Fig. As can be seen in Figure 18, each of the second teeth 16 has a centerline CL2 extending radially from the rotational axis A of the bicycle sprocket 810. Each of the second teeth 16 has a symmetrical shape with respect to the centerline CL2. More specifically, each of the second teeth 16 has a symmetrical shape with respect to the centerline CL2 when viewed from the direction of the rotational axis A.

[0047] As in Fig. 20, the center line CL2 is perpendicular to the rotation axis A. Each of the second teeth 16 has a symmetrical shape with respect to the center line CL2 when viewed from the circumferential direction D1 of the bicycle sprocket 810.

[0048] In the bicycle sprocket 810, since each of the sprocket teeth 12 has a symmetrical shape with respect to the center line CL1 or CL2, both circumferential sides of the sprocket tooth 12 can be used as a drive side configured to face in the rotational drive direction D11. This allows the bicycle sprocket 810 to be used as a reversible sprocket in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0049] A bicycle sprocket 910 according to a ninth embodiment will be described below with reference to the Fig. 21 to 23. The bicycle sprocket 910 has the same configuration as the bicycle sprocket 10 except for the sprocket teeth 12. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0050] As in the Fig. 21 and Fig. 22, in the bicycle sprocket 910, the at least one first tooth 14 includes a first radial contact portion 916 which is configured to contact at least one of the intermediate portions 1g of the outer connecting plates 1d of the bicycle chain 1 in a radial direction D4 ( Fig. 22) of the bicycle sprocket 910 in a state where the at least one first tooth 14 engages with the outer link plates 1d of the bicycle chain 1. The first tooth 14 includes a first tooth body 962 projecting radially outward from the first radial contact portion 960. The first radial contact portion 960 is closer to the tooth bottom 12a than the first tooth body 962. A radial outer surface 960a of the first radial contact portion 960 has a shape complementary to an outer shape of the intermediate portion 1g of the outer link plate 1d. More specifically, the radial outer surface 960a of the first radial contact portion 960 has a curved shape and is provided along an edge of the intermediate portion 1g of the outer link plate 1d.

[0051] As in Fig. As can be seen in Figure 22, the first tooth body 962 has the first axial chain engagement width W1. The first tooth body 962 includes the first chain engagement surface 14b and the second chain engagement surface 14c. The first radial contact portion 960 has a first axial width W41, which is larger than the first distance L1 defined between the opposing outer link plates 1d of the bicycle chain 1. The first axial width W41 is larger than the first axial chain engagement width W1.

[0052] As in Fig. As can be seen in Figure 22, the first radial contact portion 960 protrudes from the first chain engagement surface 14b and the second chain engagement surface 14c in the axial direction D3. However, the first radial contact portion 960 may protrude from at least one of the first chain engagement surface 14b and the second chain engagement surface 14c.

[0053] As in the Fig. 21 and Fig. 23, the at least one second tooth 16 includes a second radial contact portion 964 which is designed to contact at least one of the intermediate portions 1h of the inner connecting plates 1c of the bicycle chain 1 in the radial direction D4 ( Fig. 23) of the bicycle sprocket 10 in a state where the at least one second tooth 16 engages with the inner link plate 1c of the bicycle chain 1. The second tooth 16 includes a second tooth body 966 projecting radially outward from the second radial contact portion 964. The second radial contact portion 964 is closer to the tooth bottom 12a than the second tooth body 966. A radial outer surface 964a of the second radial contact portion 964 has a shape complementary to an outer shape of the intermediate portion 1h of the inner link plate 1c. More specifically, the radial outer surface 964a of the second radial contact portion 964 has a curved shape and is provided along an edge of the intermediate portion 1h of the inner link plate 1c.

[0054] As in Fig. As can be seen in Figure 23, the second tooth body 966 has the second axial chain engagement width W2. The second tooth body 966 includes the third chain engagement surface 16b and the fourth chain engagement surface 16c. The second radial contact portion 964 has a second axial width W42, which is greater than the second distance L2 defined between the opposing inner link plates 1c of the bicycle chain 1. The second axial width W2.

[0055] As in Fig. As can be seen in Fig. 23, the second radial contact portion 964 protrudes from the third chain engagement surface 16b and the fourth chain engagement surface 16c in the axial direction D?. However, the second radial contact portion 964 may protrude from at least one of the third chain engagement surface 16b and the fourth chain engagement surface 16c.

[0056] In the bicycle chain portion 910, the first radial contact portion 960 is configured to contact the intermediate portions 1g of the outer link plates 1d of the bicycle chain 1 in the radial direction D4. Accordingly, the first radial contact portion 960 can improve the stability of the outer link plates 1d engaging with the first tooth 14, in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment. Similarly, the second radial contact portion 964 is configured to contact the intermediate portions 1h of the inner link plates 1c of the bicycle chain 1 in the radial direction D4. Accordingly, the second radial contact portion 964 can improve the stability of the inner link plates 1c engaging with the second tooth 16, in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0057] A bicycle sprocket 1010 according to a tenth embodiment will be described below with reference to Fig. 24. The bicycle sprocket 1010 has the same configuration as the bicycle sprocket 10 except for the sprocket body 18. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0058] As in Fig. 24, the bicycle sprocket 1010 includes the sprocket teeth 12. The bicycle sprocket 1010 further includes a sprocket body 1018 having an annular shape. Each of the sprocket teeth 12 is made of a first material comprising a metallic material. The sprocket body 1018 is made of a second material comprising a plastic. The bicycle sprocket 1018 further includes an annular portion 1019 having an annular shape. The sprocket teeth 12 protrude radially outward from the annular portion 1019. For example, the annular portion 1019 is made of the first material. The sprocket teeth 12 are provided integrally with the annular portion 1019 as a single unitary member. The annular portion 1019 is at least partially embedded in the sprocket body 1018.For example, the ring portion 1019 is embedded in the sprocket body 1018 by integral molding methods such as insert molding. The sprocket body 1018 is configured to be secured to the crank connecting arms 2a of the sprocket mounting member 2 by bolts (not shown).

[0059] In the bicycle sprocket 1010, it is possible to save weight of the bicycle sprocket 1010, in addition to the advantageous effects achieved by the bicycle sprocket 10 according to the first embodiment.

[0060] A bicycle sprocket 1110 according to an eleventh embodiment will be described below with reference to Fig. 25. The bicycle sprocket 1110 has the same configuration as the bicycle sprocket 10 except for the second teeth 16. Accordingly, the elements having substantially the same function as those in the first embodiment are given the same reference numerals and will not be described again in detail for the sake of brevity.

[0061] As in Fig. 25, the sprocket teeth 12 of the bicycle sprocket 1110 include the at least one first tooth 14 and the at least one second tooth 1116. In the illustrated embodiment, the sprocket teeth 12 include the plurality of first teeth 14 as the at least one first tooth 14 and a plurality of second teeth 1116 as the at least one second tooth 1116. The first teeth 14 and the second teeth 1116 are arranged alternately in the circumferential direction D1.

[0062] The at least one second tooth 1116 is adjacent to the first tooth 14 and is arranged on a downstream side in the rotational drive direction D11 of the bicycle sprocket 1110. In the illustrated embodiment, the second tooth 1116a is adjacent to the first tooth 14a and is arranged on a downstream side relative to the first tooth 14a in the rotational drive direction D11 of the bicycle sprocket 1110.

[0063] The at least one second tooth 1116 is configured to engage / come into engagement with the inner connecting plates 1c of the bicycle chain 1. The at least one second tooth 1116 has a second radial tooth height H112. The first radial tooth height H1 is greater than the second radial tooth height H112. In the illustrated embodiment, the second radial tooth height H112 of the second teeth 116 is less than the second radial tooth height H2 of the second teeth 16 according to the first embodiment. As shown in Fig.As can be seen in Figure 25, the at least one first tooth 14 is configured to engage / come into engagement with the bicycle chain 1 before the second tooth 116 engages / comes into engagement with the bicycle chain 1. For example, the first tooth 14a engages / comes into engagement with the bicycle chain 1 (the outer connecting plates 1d) before the second tooth 116a engages / comes into engagement with the bicycle chain 1 (the inner connecting plates 1c) because the first radial tooth height H1 of the first tooth 14a is greater than the second radial tooth height H112 of the second tooth 116a.

[0064] With the bicycle sprocket 1110, it is possible to achieve the same advantageous effects as the bicycle sprocket 10 according to the first embodiment.

[0065] In the above embodiments, the term "attached" or "attaching" as used herein includes configurations in which one element is directly attached to another element by attaching the element directly to the other element; configurations in which the element is indirectly attached to the other element via the intermediate member; and configurations in which one element is integrally formed with another element, i.e., one element is substantially a portion of the other element. This concept also applies to words with similar meanings, such as "connected," "joined," "coupled," "mounted," "glued," "fixed," and their derivatives, except for the terms "connected" and "connecting."

[0066] The term "comprising" and its derivatives, as used herein, are to be understood as open-ended terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers, and / or steps. The above also applies to words of similar meaning, such as the terms "comprise," "include," and their derivatives.

[0067] Furthermore, the terms “member,” “section,” “portion,” or “element,” as used in the singular, may have the plural meaning of a single part or a plurality of parts.

[0068] The atomic numbers such as "first" or "second" as cited in the present application are merely identifiers, but have no other meaning, such as a particular order or the like. Furthermore, the term "first element," for example, does not imply the existence of a "second element," nor does the term "second element" itself imply the existence of a "first element."

[0069] Finally, terms such as "substantially," "by," and "approximately" as used herein mean a reasonable amount of variation from the modified term such that the end result is not significantly altered. Of course, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

[1] Bicycle sprocket (10) comprising: sprocket teeth (12) including at least one first tooth (14) configured to engage with outer connecting plates (1d) of a bicycle chain (1) and having a first radial tooth height (H1), wherein the at least one first tooth (14) has a first axial chain engagement width (W1) that is smaller than a first distance (L1) defined between opposing outer connecting plates (1d) of the bicycle chain (1) and greater than a second distance (L2) defined between opposing inner connecting plates (1c) of the bicycle chain (1), wherein the at least one first tooth (14) includes a chamfered portion (222) adjacent to a first tooth bottom (14a) of the at least one first tooth (14), wherein the chamfered portion (222) extends from the first tooth bottom (14a) to one end of the at least one first tooth (14), and at least one second tooth (16) adjacent to the first tooth (14), wherein the at least one second tooth (16) is configured to engage / come into engagement with inner connecting plates (1c) of the bicycle chain (1), wherein the at least one second tooth (16) has a second radial tooth height (H2), wherein the at least one second tooth (16) has a second axial chain engagement width (W2) which is less than the second distance (L2), and wherein the first radial tooth height (H1) is greater than the second radial tooth height (H2). [2] The bicycle sprocket (10) of claim 1, wherein the sprocket teeth (12) include a plurality of first teeth (14) as the at least one first tooth (14) and a plurality of second teeth (16) as the at least one second tooth (16). [3] Bicycle sprocket (10) according to claim 1 or 2, wherein the at least one first tooth (14) and the at least one second tooth (16) are arranged alternately in a circumferential direction of the bicycle sprocket (10). [4] Bicycle sprocket (10) according to one of claims 1 to 3, wherein the at least one first tooth (14) is designed to engage / come into engagement with the bicycle chain (1) before the second tooth (16) engages / comes into engagement with the bicycle chain (1). [5] Bicycle sprocket (10) according to one of claims 1 to 4, wherein the chamfered portion (222) of the at least one first tooth (14) is configured to reduce the interaction between the at least one first tooth (14) and one of the inner connecting plates (1c) of the bicycle chain (1). [6] Bicycle sprocket (10) according to one of claims 1 to 5, wherein the chamfered portion (222) of the at least one first tooth (14) is configured to reduce wear of the at least one first tooth (14). [7] The bicycle sprocket (10) according to any one of claims 1 to 6, wherein the at least one first tooth (14) includes a first radial contact portion (960) configured to contact at least one of intermediate portions of the outer link plates (1d) of the bicycle chain (1) in a radial direction of the bicycle sprocket (10) in a state where the at least one first tooth (14) engages with the outer link plates of the bicycle chain, in particular, the first radial contact portion (960) has a first axial width (W1) that is greater than a first distance (L1) defined between the opposite outer link plates (1d) of the bicycle chain (1). [8] Bicycle sprocket (10) according to one of claims 1 to 7, wherein the at least one second tooth (16) includes a second radial contact portion (964) configured to contact at least one of the intermediate portions of the inner connecting plates (1c) of the bicycle chain (1) in a radial direction of the bicycle sprocket (10) in a state where the at least one second tooth (16) engages with the inner connecting plates (1c) of the bicycle chain (1), in particular, the second radial contact portion (964) has a second axial width which is greater than a second distance defined between opposite inner connecting plates (1c) of the bicycle chain (1). [9] Bicycle sprocket (10) according to one of claims 1 to 8, wherein the sprocket teeth (12) are evenly spaced from each other in a circumferential direction of the bicycle sprocket (10), each of the sprocket teeth (12) has a center line extending radially from a rotational axis of the bicycle sprocket (12) and each of the sprocket teeth (12) has a symmetrical shape with respect to the center line.

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