REAR BICYCLE CHAINRING

Abstract

Rear bicycle chainring (SS8, SS208), featuring: a sprocket body (20); a plurality of sprocket teeth (22) extending radially outwards from the sprocket body (20); a recess (28) to facilitate switching, where a bicycle chain (16) is located between the rear bicycle chainring (SS8, SS208) and a smaller rear sprocket (SS9) is shifted next to the rear bicycle sprocket (SS8, SS208) without another sprocket between the rear bicycle sprocket (SS8, SS208) and the smaller rear sprocket (SS9); and a shifting advantage (30) which, during a shifting operation, in which the bicycle chain (16) is shifted from the rear bicycle chainring (SS8, SS208) to the smaller rear chainring (SS9), in which the recess (28) facilitating the shifting is provided for storing the bicycle chain (16).

Description

[0001] The present invention relates to a rear bicycle chainring.

[0002] Cycling is becoming an increasingly popular leisure activity and means of transportation. Moreover, it has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for leisure, transportation, or competition, the bicycle industry is constantly improving its various components. One bicycle component that has been comprehensively redesigned is the chainring.

[0003] An example of a bicycle chainring is disclosed in DE 10 2016 004 822 A1. The bicycle chainring has a central axis of rotation and includes a first shifting support area, which is designed to support a first shift from a first chainring to the bicycle chainring, and a second shifting support area, which is designed to support a second shift from a second chainring to the bicycle component. The first number of teeth of the first chainring differs from the second number of teeth of the second chainring.

[0004] An example of a derailleur shifting mechanism is disclosed in EP 0 716 976 B1. The derailleur has a tooth recessed on a larger chainring in the circumferential section corresponding to the chain's movement from the smaller to the larger chainring, creating a tooth gap. This gap forms a passage for outer or inner chain connecting links. Near the tooth in front of the gap, the larger chainring has a conical rivet with a circumferential sharp edge. This rivet supports the chain at the connection in the gap between the outer and inner connecting link plates as the chain moves through the passage to the larger chainring. The tooth behind the gap is designed as a catch tooth.

[0005] According to the present invention, a rear bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, a shifting-facilitating recess, and an upshifting-facilitating projection. The plurality of sprocket teeth extend radially outward from the sprocket body. The shifting-facilitating recess is intended to facilitate a shifting operation in which a bicycle chain is shifted between the rear bicycle sprocket and a smaller rear sprocket located next to the rear bicycle sprocket, without another sprocket being positioned between the rear bicycle sprocket and the smaller rear sprocket. The upshifting-facilitating projection is provided in the shifting-facilitating recess for mounting the bicycle chain during an upshift operation in which the bicycle chain is shifted from the rear bicycle sprocket to the smaller rear sprocket.

[0006] In the rear bicycle chainring according to the present invention, the projection that facilitates upshifting brings the bicycle chain smoothly into engagement with the smaller rear chainring during the upshifting process.

[0007] According to a preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the projection facilitating upshifting is integrally formed with the sprocket body as a single, unitary component. In the case of such a rear bicycle sprocket, it can be manufactured easily.

[0008] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the projection facilitating upshifting is a component separate from the chainring body. In the case of such a rear bicycle chainring, the design freedom for the shape of the projection facilitating upshifting can be improved.

[0009] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the upshifting-facilitating projection includes a chain contact surface that can be contacted by the bicycle chain during the upshifting process. The chain contact surface is inclined perpendicular to the axis of rotation of the rear bicycle chainring with respect to a chainring center plane. The chainring center plane divides the rear bicycle chainring in an axial direction with respect to the axis of rotation. In the case of such a rear bicycle chainring, the upshifting-facilitating projection brings the bicycle chain into engagement with the smaller rear chainring even more smoothly during the upshifting process.

[0010] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the upshifting-facilitating projection includes a chain contact surface that can be contacted with the bicycle chain during the upshifting process. The chain contact surface extends in an axial direction with respect to a rotational center axis of the rear bicycle chainring. In the case of such a rear bicycle chainring, the upshifting-facilitating projection brings the bicycle chain into engagement with the smaller rear chainring even more smoothly during the upshifting process.

[0011] According to a further preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the projection facilitating upshifting includes a chain contact surface which can be contacted with the bicycle chain during the upshifting process. The chain contact surface has a flat surface. In the case of such a rear bicycle sprocket, the chain contact surface stably supports the bicycle chain during the upshifting process.

[0012] According to a further preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the upshifting-facilitating projection includes a chain contact surface which can be contacted with the bicycle chain during the upshifting process. The chain contact surface is inclined perpendicular to the axis of rotation of the rear bicycle sprocket with respect to a first radial direction, the first radial direction extending from the axis of rotation to the upshifting-facilitating projection. In the case of such a rear bicycle sprocket, the chain contact surface can be arranged so that it runs along the bicycle chain during the upshifting process.

[0013] According to a further preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the upshifting-facilitating projection includes a chain contact surface that can be contacted with the bicycle chain during the upshifting process. The chain contact surface comprises a first circumferential end and a second circumferential end. The chain contact surface extends between the first circumferential end and the second circumferential end. A first radial distance between a rotational axis of the rear bicycle sprocket and the first circumferential end is different from a second radial distance between the rotational axis and the second circumferential end. In the case of such a rear bicycle sprocket, the chain contact surface can be arranged so that it extends along the bicycle chain during the upshifting process.

[0014] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the first circumferential end is positioned in front of the second circumferential end in a drive direction of rotation in which the rear bicycle chainring is rotated about the central axis of rotation during pedaling. The first radial distance is smaller than the second radial distance. In the case of such a rear bicycle chainring, the chain contact surface can be arranged so that it runs along the bicycle chain during the upshifting process.

[0015] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the majority of the chainring teeth contain a first tooth and a second tooth. The first tooth and the second tooth are positioned within the angular dimension of the shifting-facilitating recess. The upshifting-facilitating projection is provided between the first tooth and the second tooth in a circumferential direction with respect to a rotational center axis of the rear bicycle chainring. In the case of such a rear bicycle chainring, the upshifting-facilitating projection brings the bicycle chain into engagement with the smaller rear chainring even more smoothly during the upshifting process.

[0016] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the shifting-facilitating recess is continuously provided between the first tooth and the second tooth, extending over the upshifting-facilitating projection. In the case of such a rear bicycle chainring, the upshifting-facilitating projection brings the bicycle chain into engagement with the smaller rear chainring even more smoothly during the upshifting process.

[0017] According to a further preferred aspect of the present invention, the rear bicycle chainring can be designed such that the majority of the chainring teeth include at least one drive tooth. In the case of such a rear bicycle chainring, the projection, which facilitates upshifting, brings the bicycle chain into engagement with the smaller rear chainring even more smoothly during the upshifting process.

[0018] According to a further preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the majority of the sprocket teeth include a first drive tooth and a second drive tooth. The first drive tooth has a first maximum axial width extending in an axial direction with respect to a rotational center axis of the rear bicycle sprocket. The second drive tooth has a second maximum axial width extending in the axial direction. The first maximum axial width is greater than the second maximum axial width. In the case of such a rear bicycle sprocket, the chain retention capacity of the rear bicycle sprocket can be improved while simultaneously facilitating the upshifting process.

[0019] According to a further preferred aspect of the present invention, the rear bicycle sprocket can be designed such that the sprocket body includes a first axial surface and a second axial surface, the latter being provided on the rear side of the first axial surface in an axial direction with respect to a rotational center axis of the rear bicycle sprocket. An axial end of the upshifting-facilitating projection is provided in an axial region extending from the first axial surface to the second axial surface. In the case of such a rear bicycle sprocket, the upshifting-facilitating projection brings the bicycle chain into engagement with the smaller rear sprocket even more smoothly during the upshifting process.

[0020] The invention and many of its associated advantages can be assessed more accurately when they become better understood with reference to the following detailed description in conjunction with the accompanying drawings. Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein: Fig. 1 a schematic graphic representation of a bicycle drive train, comprising a rear bicycle chainring according to a first embodiment; Fig. 2 a side view of the bicycle chainring assembly of the in Fig. 1 illustrated bicycle drivetrain is; Fig. 3 a front view of the in Fig. The bicycle chainring assembly shown in the illustration is: 2 Fig. 4 a side view of the rear bicycle chainring of the in Fig. The bicycle chainring assembly shown in the illustration is: 2 Fig. 5 a partial side view of the in Fig. 4 illustrated rear bicycle chainring is; Fig. 6 a perspective partial view of the in Fig. 4 illustrated rear bicycle chainring is; Fig. 7 a cross-sectional view of the rear bicycle chainring along line VII-VII of Fig. 5 is; Fig. 8 a cross-sectional view of the rear bicycle chainring along line VII-VII of Fig. 5 is (modification); Fig. 9 a cross-sectional view of the rear bicycle chainring along line VII-VII of Fig. 5 is (another modification); Fig. 10 a cross-sectional view of the rear bicycle chainring along line XX of Fig. 5 is; Fig. 11 a cross-sectional view of the rear bicycle chainring along line XI-XI of Fig. 5 is; Fig. 12 a cross-sectional view of the rear bicycle chainring along line XII-XII of Fig. 14 is; Fig. 13 a cross-sectional view of the rear bicycle chainring along line XII-XII of Fig. 14 is (modification); Fig. 14 an enlarged partial side view of the in Fig. 4 illustrated rear bicycle chainring is; Fig. 15 a perspective partial view of the in Fig. 4 illustrated rear bicycle chainring is; Fig. 16 a perspective partial view of the in Fig. 4 illustrated rear bicycle sprocket with a bicycle chain; Fig. 17 a perspective partial view of the in Fig. 4 illustrated rear bicycle sprocket with the bicycle chain; Fig. 18 a side view of a rear bicycle chainring according to a second embodiment; Fig. 19 a cross-sectional view of the rear bicycle chainring along the XIX-XIX line of Fig. 18 is; and Fig. 20 a cross-sectional view of the rear bicycle chainring along line XX-XX of Fig. 18.

[0021] In the description of the embodiments of the present invention, the same reference numerals in the various drawings denote corresponding or identical elements.

[0022] First, with reference to Fig. Figure 1 comprises a bicycle drivetrain 10, a bicycle sprocket assembly 12, a front bicycle sprocket 14, and a bicycle chain 16. The bicycle sprocket assembly 12 is attached to a rear bicycle hub assembly 18. The rear bicycle hub assembly 18 is mounted on a bicycle frame BF. The bicycle sprocket assembly 12 has a pivot axis A1 and is rotatably mounted by the rear bicycle hub assembly 18 with respect to the bicycle frame BF about the pivot axis A1. The bicycle chain 16 engages with the front bicycle sprocket 14 and the bicycle sprocket assembly 12, so that a drive torque F1 is transmitted between the front bicycle sprocket 14 and the bicycle sprocket assembly 12. The front bicycle sprocket 14 has a single front bicycle sprocket. In this embodiment, the bicycle chainring assembly 12 is a rear bicycle chainring assembly.The design of the bicycle chainring assembly 12 can also be applied to a front chainring assembly if the front chainring assembly has at least two front chainrings. The total number of front bicycle chainrings 14 is not limited to this embodiment.

[0023] In the present application, the following directional terms “front”, “back”, “forward”, “backward”, “left”, “right”, “across”, “more”, and “down”, as well as other similar directional terms, refer to those directions determined based on the user (e.g., a cyclist) seated on the saddle (not shown) of a bicycle facing the handlebars (not shown). Consequently, these terms, as used to describe the bicycle chainring assembly 12, should be interpreted in relation to the bicycle equipped with the bicycle chainring assembly 12 in an upright riding position on a horizontal surface.

[0024] As in Fig. As can be seen in Figure 2, the bicycle chainring assembly 12 is engaged with the bicycle chain 16, so that the drive torque F1 is transmitted between the bicycle chainring assembly 12 and the front bicycle chainring 14 ( Fig. 1) is transmitted. The bicycle chainring assembly 12 is rotatable about the axis of rotation A1 in the drive direction D11 during pedaling. The reverse direction of rotation D12 is opposite to the drive direction D11. The drive direction D11 and the reverse direction of rotation D12 are defined along the circumferential direction D1 of the bicycle chainring assembly 12.

[0025] The bicycle sprocket assembly 12 comprises the rear bicycle sprockets SS1 to SS12. Each of the rear bicycle sprockets SS1 to SS12 can be engaged with the bicycle chain 16. The rear bicycle sprockets SS1 to SS12 each correspond to the first to twelfth speed stages of the bicycle drivetrain 10. The rear bicycle sprocket SS1 corresponds to the first speed stage (i.e., the lowest gear) of the bicycle sprocket assembly 12 and has the largest bolt circle diameter of the rear bicycle sprockets SS1 to SS12. The rear bicycle sprocket SS12 corresponds to the twelfth speed stage (i.e., the highest gear) of the bicycle sprocket assembly 12 and has the smallest bolt circle diameter of the rear bicycle sprockets SS1 to SS12. The total number of rear bicycle sprockets of the bicycle sprocket assembly 12 is not limited to this embodiment.

[0026] As in Fig. As shown in Figure 3, the bicycle chainring assembly 12 also includes spacers SP1 to SP11. The spacers SP1 to SP11 are positioned between two adjacent chainrings of the rear bicycle chainrings SS1 to SS12 in an axial direction D2. At least one of the spacers SP1 to SP11 can be omitted from the bicycle chainring assembly 12.

[0027] In the bicycle chainring assembly 12, an upshift occurs when the bicycle chain 16 is moved from a larger chainring to the next smaller chainring by means of a derailleur DR in the upshift direction D31. In the bicycle chainring assembly 12, a downshift occurs when the bicycle chain 16 is moved from a smaller chainring to the next larger chainring in the downshift direction D32.

[0028] The SS8 rear bicycle chainring is described in detail below. In the following description, the SS9 rear bicycle chainring is referred to as a smaller version. The SS1 to SS7 and SS9 to SS12 rear bicycle chainrings have essentially the same construction as the SS8 rear bicycle chainring. Therefore, for the sake of brevity, they are not described in detail here.

[0029] As in Fig. As shown in Figure 4, the rear bicycle sprocket SS8 has a sprocket body 20 and a plurality of sprocket teeth 22 extending radially outwards from the sprocket body 20. The sprocket body 20 includes a hub engagement structure 24 for engaging with the rear hub assembly 18. The plurality of sprocket teeth 22 includes at least one drive tooth 26. In this embodiment, the plurality of sprocket teeth 22 includes a plurality of drive teeth 26. The drive tooth 26 can engage with the bicycle chain 16 and transmit the drive torque F1 between the rear bicycle sprocket SS8 and the bicycle chain 16. The total number of sprocket teeth 22 is 18. However, the total number of sprocket teeth 22 is not limited to this embodiment.

[0030] As in Fig. As can be seen in Figure 4, the rear bicycle chainring SS8 has a recess 28 to facilitate shifting, in which the bicycle chain 16 ( Fig. 3) between the rear bicycle chainring SS8 and the smaller rear chainring SS9 ( Fig. 3) next to the rear bicycle chainring SS8 without another chainring between the rear bicycle chainring SS8 and the smaller rear chainring SS9 ( Fig. 3) is shifted. In this embodiment, the rear bicycle chainring SS8 has a plurality of recesses 28 to facilitate shifting. However, the total number of recesses 28 to facilitate shifting is not limited to this embodiment. The recess 28 to facilitate shifting is provided on the chainring body 20 to facilitate the shifting process.

[0031] As in Fig. As shown in Figure 5, the rear bicycle chainring SS8 has a projection 30 to facilitate upshifting. This projection is located in the shift-facilitating recess 28 for the storage of the bicycle chain 16 during an upshifting operation in which the bicycle chain 16 is shifted from the rear bicycle chainring SS8 to the smaller rear chainring SS9. However, the total number of upshift-facilitating projections 30 is not limited to this embodiment. The rear bicycle chainring SS8 can have a plurality of upshift-facilitating projections 30.

[0032] The majority of the chainring teeth 22 contain a first tooth 32 and a second tooth 34. The first tooth 32 and the second tooth 34 are positioned at an angular distance RG1 within the shifting-facilitating recess 28. The upshifting-facilitating projection 30 is located between the first tooth 32 and the second tooth 34 in the circumferential direction D1 with respect to the rotational center axis A1 of the rear bicycle chainring SS8.

[0033] In this embodiment, the first tooth 32 can engage with the bicycle chain 16 and transmit a drive torque F1 between the rear bicycle chainring SS8 and the bicycle chain 16. The second tooth 34 can engage with the bicycle chain 16 and transmit the drive torque F1 between the rear bicycle chainring SS8 and the bicycle chain 16. The second tooth 34 is positioned in front of the first tooth 32 in the direction of drive rotation D11. The second tooth 34 is located next to the first tooth 32 in the circumferential direction D1, without any other tooth between the first tooth 32 and the second tooth 34.

[0034] The upshifting-facilitating projection 30 is provided radially inwards on a tooth root TB1, which is located between the first tooth 32 and the second tooth 34. Viewed along the axis of rotation A1, the upshifting-facilitating projection 30 lies on a reference line RL. The reference line RL extends from the axis of rotation A1 to the tooth root TB1.

[0035] As in Fig. As can be seen in Figure 5, the majority of the chainring teeth 22 contain a third tooth 36 and a fourth tooth 38. The third tooth 36 and the fourth tooth 38 are positioned within the angular width RG1 of the shifting-facilitating recess 28. The third tooth 36 can engage with the bicycle chain 16 and transmit the drive torque F1 between the rear bicycle chainring SS8 and the bicycle chain 16. The fourth tooth 38 can also engage with the bicycle chain 16 and transmit the drive torque F1 between the rear bicycle chainring SS8 and the bicycle chain 16. The fourth tooth 38 is positioned in front of the third tooth 36 in the direction of drive rotation D11. The fourth tooth 38 lies next to the third tooth 36 in the circumferential direction D1, without any other tooth between the third tooth 36 and the fourth tooth 38.

[0036] The third tooth 36 is positioned in front of the second tooth 34 in the drive direction D11. In the circumferential direction D1, the third tooth 36 lies next to the second tooth 34 without any other tooth between the second tooth 34 and the third tooth 36. At least one of the third tooth 36 and one of the fourth tooth 38 can be omitted from the sprocket teeth 22.

[0037] As in Fig. As can be seen in Figure 6, the shifting-facilitating recess 28 is provided continuously between the first tooth 32 and the second tooth 34 over the upshifting-facilitating projection 30. In this embodiment, the shifting-facilitating recess 28 is provided continuously between the first tooth 32 and the fourth tooth 38 over the upshifting-facilitating projection 30 in the circumferential direction D1.

[0038] As in Fig. As shown in Figure 7, the sprocket body 20 comprises a first axial surface 20A and a second axial surface 20B, which is located on the rear side of the first axial surface 20A in the axial direction D2 with respect to the axis of rotation A1 of the rear bicycle sprocket SS8. The first axial surface 20A faces the smaller rear sprocket SS9 in the axial direction D2. The second axial surface 20B faces the opposite side of the smaller rear sprocket SS9 in the axial direction D2. The sprocket body 20 has a sprocket center plane CP1 perpendicular to the axis of rotation A1 of the rear bicycle sprocket SS8. The sprocket center plane CP1 divides the rear bicycle sprocket SS8 in the axial direction D2 with respect to the axis of rotation A1. The sprocket body 20 has a maximum axial width W1, which is defined between the first axial surface 20A and the second axial surface 20B in the axial direction D2.The sprocket center plane CP1 divides the maximum axial width W1.

[0039] The shifting-facilitating recess 28 is provided on the first axial surface 20A to facilitate the shifting process. The shifting-facilitating recess 28 includes a side surface 28A. The side surface 28A faces the smaller rear sprocket SS9 in the axial direction D2. The side surface 28A is offset in the axial direction D2 from the first axial surface 20A towards the second axial surface 20B. The side surface 28A is located in the axial direction D2 between the first axial surface 20A and the sprocket center plane CP1.

[0040] As in Fig. As shown in Figure 7, the first tooth 32 includes a first surface 32A and a first additional surface 32B. The first surface 32A faces the smaller rear sprocket SS9 in the axial direction D2. The first surface 32A is offset in the axial direction D2 from the first axial surface 20A in the direction of the second axial surface 20B. The first surface 32A is located in the same axial position as the side surface 28A. The first additional surface 32B faces the opposite side of the smaller rear sprocket SS9 in the axial direction D2. The first additional surface 32B is located in the same axial position as the second axial surface 20B.

[0041] The first tooth 32 has a first maximum axial width W21. The first maximum axial width W21 is provided in the axial direction D2 between the first surface 32A and the first additional surface 32B. The bicycle chain 16 includes an opposing pair of outer plate plates 16A and an opposing pair of inner plate plates 16B. The first tooth 32 can engage in an outer plate space 16A1 provided between the opposing pair of outer plate plates 16A. The first tooth 32 can engage in an inner plate space 16B1 provided between the opposing pair of inner plate plates 16B.

[0042] An axial end 30A of the upshifting-facilitating projection 30 is provided in an axial region AR1 that extends from the first axial surface 20A to the second axial surface 20B. In this embodiment, the axial end 30A of the upshifting-facilitating projection 30 is located in the axial direction D2 at the same axial position as the first axial surface 20A. As shown in Fig. As can be seen in Figure 8, the axial end 30A of the upshifting-facilitating projection 30 can also be located closer to the second axial surface 20B than the first axial surface 20A in the axial direction D2. As shown in Figure 8, the axial end 30A of the projection 30, which facilitates upshifting, can also be located closer to the second axial surface 20B than the first axial surface 20A. Fig. As can be seen in Figure 9, the axial end 30A of the upshifting-facilitating projection 30 can be provided outside the axial area AR1.

[0043] As in Fig. As can be seen in Figure 10, the second tooth 34 contains a second surface 34A and a second additional surface 34B. The second surface 34A faces the smaller rear sprocket SS9 in the axial direction D2. The second surface 34A is offset in the axial direction D2 from the first axial surface 20A in the direction of the second axial surface 20B. The second surface 34A is located in the same axial position as the side surface 28A. The second additional surface 34B faces the opposite side of the smaller rear sprocket SS9 in the axial direction D2. The second additional surface 34B is located in the same axial position as the second axial surface 20B.

[0044] The second tooth 34 has a second maximum axial width W22. This second maximum axial width W22 is located in the axial direction D2 between the second surface 34A and the second additional surface 34B. The second tooth 34 can engage in the outer lug space 16A1. The second tooth 34 can engage in the inner lug space 16B1.

[0045] As in Fig. As can be seen in Figure 11, the drive tooth 26 comprises a tooth surface 26A and an additional tooth surface 26B. The tooth surface 26A faces the smaller rear sprocket SS9 in the axial direction D2. The tooth surface 26A is located in the same axial position as the first axial surface 20A. The additional tooth surface 26B is located in the axial direction D2 opposite the smaller rear sprocket SS9. The additional tooth surface 26B is located in the same axial position as the second axial surface 20B. That is, the drive tooth 26 has a maximum axial width W3 equal to the maximum axial width W1 of the sprocket body 20.

[0046] The third tooth 36 and the fourth tooth 38 have essentially the same construction as the first tooth 32 or the second tooth 34. Therefore, for the sake of brevity, they are not described in detail here.

[0047] As in Fig. As shown in Figure 4, the rear bicycle chainring SS8 has a plurality of shifting-facilitating recesses 28. The plurality of chainring teeth 22 includes a plurality of first teeth 32, a plurality of second teeth 34, and a plurality of third teeth 36. The first tooth 32, the second tooth 34, and the third tooth 36 are provided in each of the shifting-facilitating recesses 28. The fourth tooth 38 is provided in one of the shifting-facilitating recesses 28 (shifting-facilitating recess 28X). However, the total number of shifting-facilitating recesses 28 is not limited to this embodiment. However, the total number of first teeth 32 is not limited to this embodiment. However, the total number of second teeth 34 is not limited to this embodiment. However, the total number of third teeth 36 is not limited to this embodiment.

[0048] In this embodiment, the upshifting-facilitating projection 30 is provided between one of the first teeth 32 (the first tooth 32X) and one of the second teeth 34 (the second tooth 34X) in the circumferential direction D1 with respect to the rotational center axis A1 of the rear bicycle sprocket SS8. However, the rear bicycle sprocket SS8 can also have a plurality of upshifting-facilitating projections 30, and another of the upshifting-facilitating projections 30 can be provided in another of the shifting-facilitating recesses 28.

[0049] As in Fig. As can be seen in Figure 12, the upshifting-facilitating projection 30 extends from the side surface 28A of the shifting-facilitating recess 28 in the axial direction D2. The upshifting-facilitating projection 30 is integrally formed with the sprocket body 20 as a single, unitary component. As shown in Fig. As can be seen in Figure 13, the upshifting projection 30 can also be provided as a separate component from the sprocket body 20. In this embodiment, the sprocket body 20 and the upshifting projection 30 are made of a metallic material such as iron, titanium, or aluminum.

[0050] As in Fig. As shown in Figure 12, the upshifting projection 30 includes a chain contact surface 30B, which can be contacted by the bicycle chain 16 during the upshifting process. The chain contact surface 30B extends from the side surface 28A of the shifting-facilitating recess 28 in the axial direction D2. In this embodiment, the chain contact surface 30B is inclined perpendicular to the axis of rotation A1 of the rear bicycle chainring SS8 with respect to the sprocket center plane CP1. However, the chain contact surface 30B can also be perpendicular to the sprocket center plane CP1.

[0051] As in Fig. As can be seen in Figure 14, the chain contact surface 30B is inclined perpendicular to the axis of rotation A1 of the rear bicycle sprocket SS8 with respect to a first radial direction D4. The first radial direction D4 extends from the axis of rotation A1 to the projection 30 that facilitates upshifting. In this embodiment, the first radial direction D4 is parallel to the reference line RL.

[0052] The chain contact surface 30B comprises a first circumferential end 30B1 and a second circumferential end 30B2. The chain contact surface 30B extends between the first circumferential end 30B1 and the second circumferential end 30B2. In this embodiment, the first circumferential end 30B1 is positioned in front of the second circumferential end 30B2 in the drive rotation direction D11, in which the rear bicycle chainring SS8 is rotated about the central axis of rotation A1 during pedaling.

[0053] As in Fig. As can be seen in Figure 14, a first radial distance RD1 between the axis of rotation A1 of the rear bicycle sprocket SS8 and the first circumferential end 30B1 differs from a second radial distance RD2 between the axis of rotation A1 and the second circumferential end 30B2. The first radial distance RD1 is smaller than the second radial distance RD2. However, the first radial distance RD1 can also be equal to or greater than the second radial distance RD2.

[0054] As in Fig. As can be seen in Figure 15, in this embodiment the chain contact surface 30B contains a flat surface. The axial end 30A contains a flat surface. At least one of the axial end 30A and the chain contact surface 30B can contain a curved surface instead of or in addition to the flat surface.

[0055] As in Fig. As can be seen in diagram 16, during the upshifting process, the bicycle chain 16 is shifted in the axial direction D2 by the front derailleur DR onto the smaller rear chainring SS9. For example, the bicycle chain 16 (the opposite pair of inner plate plates 16B2) is first released from the rear bicycle chainring SS8 at the first tooth 32.

[0056] As in Fig. As shown in Figure 17, the outer link plate 16A2 of the bicycle chain 16 is lifted by the upshifting projection 30 when the rear bicycle sprocket SS8 continues to rotate in the drive direction D11 after the inner link plates 16B2 have first been released at the first tooth 32. The bicycle chain 16 travels along path RT1 when the outer link plate 16A2 of the bicycle chain 16 is lifted by the upshifting projection 30. Path RT1 is longer than path RT2, along which the bicycle chain 16 would travel without the upshifting projection 30. Thus, the upshifting projection 30 smoothly engages the bicycle chain 16 with the smaller rear sprocket SS9 during the upshifting process, in which the bicycle chain 16 is shifted from the rear bicycle sprocket SS8 to the smaller rear sprocket SS9.

[0057] Below, a rear bicycle chainring SS208 according to a second embodiment is described with reference to the Fig. Sections 18 to 20 describe the rear bicycle chainring SS208. It has the same construction and / or design as the rear bicycle chainring SS8, except for the drive tooth 26. Therefore, elements with essentially the same function as in the first embodiment are numbered the same here and, for the sake of brevity, are not described and / or illustrated again in detail.

[0058] As in Fig. As shown in Figure 18, the majority of the sprocket teeth 22 of the rear bicycle sprocket SS208 contain a first drive tooth 226 and a second drive tooth 227. In this embodiment, the majority of the sprocket teeth 22 contain a majority of first drive teeth 226 and a majority of second drive teeth 227. However, the total number of first drive teeth 226 is not limited to this embodiment. The total number of second drive teeth 227 is also not limited to this embodiment.

[0059] As in Fig. As can be seen in Figure 19, the first drive tooth 226 has a first maximum axial width W231, which extends in the axial direction D2 with respect to the rotational center axis A1 of the rear bicycle sprocket SS208. As shown in Fig.As can be seen in Figure 20, the second drive tooth 227 has a second maximum axial width W232, which runs in the axial direction D2. The first maximum axial width W231 is larger than the second maximum axial width W232. The first maximum axial width W231 is larger than the axial width of the inner link space 16B1 of the bicycle chain 16. The first maximum axial width W231 is smaller than the axial width of the outer link space 16A1 of the bicycle chain 16.

[0060] The designs of the first drive tooth 226 and the second drive tooth 227 can be applied to the other sprockets SP1 to SP7 and SP9 to SP12.

[0061] It is obvious that, in light of the above teachings, numerous modifications and variations of the present invention are possible. It is therefore understood that, within the scope of the appended claims, the invention can also be implemented differently than specifically described herein. LIST OF REFERENCE MARKS 10 Bicycle drivetrain 12 Bicycle chainring assembly 14 front bicycle chainring 16 bicycle chain 16A, 16A2 Outer flange plates 16A1 Outer flap space 16B, 16B2 inner flange plates 16B1 Inner flap space 18 rear hub assembly 20 sprocket bodies 20A first axial surface 20B second axial surface 22 sprocket teeth 24 Hub engagement design 26 drive tooth 26A Tooth surface 26B additional tooth surface 28, 28X recess to facilitate shifting 28A Side surface 30, making upshifting easier, advantage 30A axial end 30B Chain contact surface 30B1 first end of circumference 30B2 second end of perimeter 32, 32X first tooth 32A first area 32B first additional area 34, 34X second tooth 34A second area 34B second additional area 36 third tooth 38 fourth tooth 226 first drive tooth 227 second drive tooth A1 pivot axis AR1 axial area BF bicycle frame CP1 sprocket center level D1 Circumferential direction D11 Drive direction of rotation D12 Reverse rotation D2 axial direction D31 Upward switching direction D32 Downward switching direction D4 first radial direction DR front derailleur F1 drive torque RD1 first radial distance RD2 second radial distance RG1 Angle of incidence RL reference line RT1, RT2 path SP1 to SP11 spacers SS1 to SS12, SS208 rear bicycle chainrings TB1 Tooth base W1, W3 maximum axial width W21, W231 first maximum axial width W22, W232 second maximum axial width

Claims

[1] Rear bicycle chainring (SS8, SS208), comprising: a sprocket body (20); a plurality of sprocket teeth (22) extending radially outwards from the sprocket body (20); a recess (28) to facilitate switching, where a bicycle chain (16) is located between the rear bicycle chainring (SS8, SS208) and a smaller rear sprocket (SS9) is shifted next to the rear bicycle sprocket (SS8, SS208) without another sprocket between the rear bicycle sprocket (SS8, SS208) and the smaller rear sprocket (SS9); and a shifting advantage (30) which, during a shifting operation, in which the bicycle chain (16) is shifted from the rear bicycle chainring (SS8, SS208) to the smaller rear chainring (SS9), in which the recess (28) facilitating the shifting is provided for storing the bicycle chain (16). [2] Rear bicycle chainring (SS8, SS208) according to claim 1, wherein the upshifting-facilitating projection (30) is integrally provided with the chainring body (20) as a one-piece, unitary component. [3] Rear bicycle chainring (SS8, SS208) according to claim 1, wherein the upshifting-facilitating projection (30) is a component separate from the chainring body (20). [4] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the upshifting-facilitating projection (30) includes a chain contact surface (30B) which can be contacted with the bicycle chain (16) during the upshifting process, the chain contact surface (30B) is inclined perpendicular to the rotation axis (A1) of the rear bicycle sprocket (SS8, SS208) with respect to a sprocket center plane (CP1) and the sprocket center plane (CP1) divides the rear bicycle sprocket (SS8, SS208) in an axial direction (D2) with respect to the rotation center axis (A1). [5] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the upshifting-facilitating projection (30) includes a chain contact surface (30B) which can be contacted with the bicycle chain (16) during the upshifting process, and the chain contact surface (30B) runs in an axial direction (D2) with respect to a rotational center axis (A1) of the rear bicycle sprocket (SS8, SS208). [6] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the upshifting-facilitating projection (30) includes a chain contact surface (30B) which can be contacted with the bicycle chain (16) during the upshifting process, and the chain contact surface (30B) contains a flat surface. [7] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the upshifting-facilitating projection (30) includes a chain contact surface (30B) which can be contacted with the bicycle chain (16) during the upshifting process, and the chain contact surface (30B) is inclined with respect to a first radial direction (D4) perpendicular to the axis of rotation (A1) of the rear bicycle sprocket (SS8, SS208), wherein the first radial direction (D4) extends from the axis of rotation (A1) to the projection (30) that facilitates upshifting. [8] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the upshifting-facilitating projection (30) includes a chain contact surface (30B) which can be contacted with the bicycle chain (16) during the upshifting process, the chain contact surface (30B) contains a first circumferential end (30B1) and a second circumferential end (30B2), the chain contact surface (30B) runs between the first circumferential end (30B1) and the second circumferential end (30B2), and a first radial distance (RD1) between a rotation center axis (A1) of the rear bicycle sprocket (SS8, SS208) and the first circumferential end (30B1) differs from a second radial distance (RD2) between the rotation center axis (A1) and the second circumferential end (30B2). [9] Rear bicycle chainring (SS8, SS208) according to claim 8, wherein the first circumferential end (30B1) is provided in a drive rotation direction (D11) in which the rear bicycle chainring (SS8, SS208) is rotated about the central axis of rotation (A1) during pedaling, in front of the second circumferential end (30B2), and the first radial distance (RD1) is smaller than the second radial distance (RD2). [10] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the majority of sprocket teeth (22) contain a first tooth (32, 32X) and a second tooth (34, 34X), the first tooth (32, 32X) and the second tooth (34, 34X) are provided in an angular width (RG1) of the shifting-facilitating recess (28) and the upshifting facilitated projection (30) between the first tooth (32, 32X) and the second tooth (34, 34X) in a circumferential direction (D1) with respect to a rotational center axis (A1) of the rear bicycle sprocket (SS8, SS208) is provided. [11] Rear bicycle chainring (SS8, SS208) according to claim 10, wherein the shifting-facilitating recess (28) is provided continuously between the first tooth (32, 32X) and the second tooth (34, 34X) over the upshifting-facilitating projection (30). [12] Rear bicycle chainring (SS8) according to one of the preceding claims, wherein the plurality of chainring teeth (22) includes at least one drive tooth (26). [13] Rear bicycle sprocket (SS208) according to one of the preceding claims, wherein the plurality of sprocket teeth (22) includes a first drive tooth (226) and a second drive tooth (227), the first drive tooth (226) has a first maximum axial width (W231) which extends in an axial direction (D2) with respect to a rotational center axis (A1) of the rear bicycle sprocket (SS208), the second drive tooth (26) has a second maximum axial width (W232) which extends in the axial direction (D2), and the first maximum axial width (W231) is greater than the second maximum axial width (W232). [14] Rear bicycle chainring (SS8, SS208) according to one of the preceding claims, wherein the sprocket body (20) includes a first axial surface (20A) and a second axial surface (20B) which is provided in an axial direction (D2) with respect to a rotational center axis (A1) of the rear bicycle sprocket (SS8, SS208) on the back of the first axial surface (20A), and an axial end (30A) of the upshifting-facilitating projection (30) is provided in an axial area (AR1) that extends from the first axial surface (20A) to the second axial surface (20B).

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