Conical bicycle tower sprocket chain wheel structure

Abstract

A conical bicycle tower wheel has a unitary sprocket assembly. Each annular portion of the sprocket individual is mechanically supported from a rear portion of the sprocket in an axial direction toward a bicycle hub or from an interior radial direction toward a centerline axis of the bicycle tower wheel and hub. Axial support zones and radial support zones alternate around the circumference of the sprocket such that the sprocket as a whole is supported in either axial or radial directions. In this way, chain drive loads on the tower wheel are spread throughout the tower wheel and areas of high localized stress concentration in the tower wheel are eliminated.

Description

[0001] Related applications

[0002] This invention claims priority to co-pending U.S. Provisional Patent Application No. 63 / 053,424, filed July 17, 2021, entitled “CONICAL BICYCLECASSETTE SPROCKET STRUCTURE”, which is incorporated herein by reference in its entirety under 35 U.SC119(e). Technical Field

[0003] This invention generally relates to a conical integral sprocket structure for a bicycle cassette. More specifically, this invention relates to a conical integral sprocket structure for a bicycle cassette, the sprocket structure having multiple sprocket individuals connected to form the bicycle cassette. Background Technology

[0004] A single, tapered sprocket assembly used to support multiple sprocket components for a tow wheel is typically machined from a single piece of material. Holes and / or windows can be machined into the sprocket assembly to reduce its overall weight. However, this weight reduction may result in a smaller annular dimension and / or cross-section of the individual sprockets, and the sprockets themselves being unsupported in the radial or axial directions. Instead, this assembly relies on the flat shape of the sprockets to transmit driving force from the drive chain to the wheel hub.

[0005] The resulting small, unsupported portions of the sprocket assembly create areas of highly localized stress concentration within the material, particularly in the recessed areas of the sprocket teeth. These areas of high stress concentration can cause premature failure of the unsupported areas of the bicycle cassette, especially for ultra-low-weight cassettes. Conversely, if the thickness of the unsupported areas is designed to be sufficiently strong to support these stress-concentrated areas, the overall weight of the sprocket assembly and the bicycle cassette can become unnecessarily high. Summary of the Invention

[0006] The tapered bicycle cassette features a single, integrated sprocket assembly. Each annular segment of the sprocket is mechanically supported either axially toward the bicycle hub from the rear of the sprocket or radially inward toward the centerline of the cassette and hub. The axial and radial support sections alternate around the circumference of the sprocket, ensuring the entire sprocket is supported axially or radially. In this way, the chain-driven load on the cassette is distributed throughout the entire cassette, eliminating areas of high localized stress concentration.

[0007] In a first aspect, the tapered bicycle sprocket includes an integral sprocket assembly comprising a first sprocket formed on the integral sprocket assembly, and a second sprocket formed on the integral sprocket assembly and connected to the first sprocket via a plurality of connecting portions, wherein each of the connecting portions includes a vertical segment spanning a radial distance between the inner diameters of the first and second sprockets and an axial transition segment spanning an axial distance between the inner diameters of the first and second sprockets. In some embodiments, each of the plurality of connecting portions includes one or more machined windows. In some embodiments, the first and second sprockets each include a plurality of repeating radial support sections and axial support sections around the circumference of the first and second sprockets. In some embodiments, the first sprocket includes one more tooth than the second sprocket.

[0008] The first aspect relates to a conical bicycle sprocket. The sprocket includes a sprocket locking screw, a large sprocket assembly having one or more large sprockets, and an integral small sprocket assembly connected to the large sprocket assembly by the sprocket locking screw. The integral small sprocket assembly has a central axis and includes a first sprocket having a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members; and a second sprocket having a plurality of outwardly extending second gear teeth and a smaller inner circumference opposite to the second gear teeth. The third sprocket has a plurality of outwardly extending third gear teeth and a third inner circumference larger than the first inner circumference opposite to the third gear teeth, wherein a first radial support member extends radially from the inner circumference toward the central axis, bends toward the second sprocket, and is connected to the second sprocket at a level of the second inner circumference, and further wherein a first axial support member extends toward the third sprocket in an axial direction parallel to the central axis, bends toward the third sprocket, and is connected to the third inner circumference of the third sprocket.

[0009] In some embodiments, each of the plurality of first radial support members and the plurality of first axial support members has one or more machined windows. In some embodiments, the plurality of first radial support members are offset from the plurality of first axial support members along a first inner circumference of the first sprocket. In some embodiments, the positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternating, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members. In some embodiments, the number of first gear teeth is greater than the number of second gear teeth and less than the number of third gear teeth. In some embodiments, the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are curved in a direction aligned with the central axis. In some embodiments, in a direction aligned with the central axis, a large portion of the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are straight. In some embodiments, the third sprocket is the largest sprocket in the integral small sprocket assembly, and further, the third sprocket has a plurality of tabs extending radially in opposite directions from the third inner circumference in the same plane as the third gear teeth. In some embodiments, the large sprocket assembly includes a plurality of locking flanges, each having a notch, and further, each of the tabs is positioned within one of the notches to engage the large sprocket assembly to the integral small sprocket assembly. In some embodiments, each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion. In some embodiments, the curved portion is a curved shape extending about a central axis.

[0010] The second aspect relates to an integral sprocket assembly having a central axis. The integral sprocket assembly includes a first sprocket having a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members; a second sprocket having a plurality of outwardly extending second gear teeth and a second inner circumference smaller than the first inner circumference opposite to the second gear teeth; and a third sprocket having a plurality of outwardly extending third gear teeth and a third inner circumference larger than the first inner circumference opposite to the third gear teeth, wherein the first radial support members extend radially from the inner circumference toward the central axis, bend toward the second sprocket, and are connected to the second sprocket at a level of the second inner circumference, and further wherein the first axial support members extend toward the third sprocket in an axial direction parallel to the central axis, bend toward the third sprocket, and are connected to the third inner circumference of the third sprocket.

[0011] In some embodiments, each of the plurality of first radial support members and the plurality of first axial support members has one or more machined windows. In some embodiments, the plurality of first radial support members are offset from the plurality of first axial support members along a first inner circumference of the first sprocket. In some embodiments, the positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternating, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members. In some embodiments, the number of first gear teeth is greater than the number of second gear teeth and less than the number of third gear teeth. In some embodiments, the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are curved in a direction aligned with the central axis. In some embodiments, in a direction aligned with the central axis, a large portion of the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are straight. In some embodiments, the third sprocket is the largest sprocket in the integral sprocket assembly, and further, the third sprocket has a plurality of tabs extending radially in opposite directions from the third inner circumference in the same plane as the third gear teeth. In some embodiments, each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion. In some embodiments, the curved portion is a curved shape extending about a central axis.

[0012] The third aspect relates to a method for providing a conical bicycle toggle wheel. The method includes providing a large sprocket assembly having one or more large sprockets, and connecting an integral small sprocket assembly to the large sprocket assembly using a sprocket locking screw, wherein the integral small sprocket assembly has a central axis and includes a first sprocket having a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members; a second sprocket having a plurality of outwardly extending second gear teeth and a second inner circumference smaller than the first inner circumference opposite to the second gear teeth; and a third sprocket having a plurality of outwardly extending third gear teeth and a third inner circumference larger than the first inner circumference opposite to the third gear teeth, wherein the first radial support members extend radially from the inner circumference toward the central axis, bend toward the second sprocket, and connect to the second sprocket at a level of the second inner circumference, and further wherein the first axial support members extend toward the third sprocket in an axial direction parallel to the central axis, bend toward the third sprocket, and connect to the third inner circumference of the third sprocket.

[0013] In some embodiments, each of the plurality of first radial support members and the plurality of first axial support members has one or more machined windows. In some embodiments, the plurality of first radial support members are offset from the plurality of first axial support members along a first inner circumference of the first sprocket. In some embodiments, the positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternating, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members. In some embodiments, the number of first gear teeth is greater than the number of second gear teeth and less than the number of third gear teeth. In some embodiments, the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are curved in a direction aligned with the central axis. In some embodiments, in a direction aligned with the central axis, a large portion of the left and right profiles of each of the plurality of radial support members and the left and right profiles of each of the plurality of axial support members are straight. In some embodiments, the third sprocket is the largest sprocket in the integral small sprocket assembly, and further, the third sprocket has a plurality of tabs extending radially in opposite directions from the third inner circumference in the same plane as the third gear teeth. In some embodiments, the large sprocket assembly includes a plurality of locking flanges, each having a notch, and the method further includes sliding each of the tabs into one of the notches before screwing in the sprocket locking screw to engage the large sprocket assembly to the integral small sprocket assembly. In some embodiments, each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion. In some embodiments, the curved portion is a curved shape extending about a central axis. Attached Figure Description

[0014] Figure 1 An external isometric view of a complete tower wheel assembly mounted to a rear bicycle hub according to some embodiments is shown.

[0015] Figure 2 A complete tower wheel assembly is shown, installed to the rear bicycle hub according to some embodiments.

[0016] Figure 3 An isometric view of a rear bicycle wheel hub according to some embodiments is shown.

[0017] Figure 4 An isometric view of a hub drive assembly according to some embodiments is shown.

[0018] Figure 5 An isometric external view of a complete tower wheel assembly mounted to a hub drive according to some embodiments is shown.

[0019] Figure 6 An exploded view of the complete tower wheel assembly and hub drive according to some embodiments is shown.

[0020] Figure 7 An isometric external view of a sprocket assembly according to some embodiments is shown.

[0021] Figure 8 The diagram shows the sprocket portion and sprocket sleeve of the sprocket according to some embodiments.

[0022] Figure 9 An isometric external view of the sprocket portion of the tower wheel according to some embodiments is shown.

[0023] Figure 10 An isometric internal view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0024] Figure 11 A top view of a sprocket assembly according to some embodiments is shown.

[0025] Figure 12 A cross-sectional view of a sprocket assembly and sleeve according to some embodiments is shown.

[0026] Figure 13 An exploded view of a sprocket assembly according to some embodiments is shown.

[0027] Figure 14 An isometric external view of the sprocket section of the tower wheel is shown according to some embodiments.

[0028] Figure 15 An isometric internal view of the sprocket section of the tower wheel is shown according to some embodiments.

[0029] Figure 16 An isometric external view of the sprocket section of the tower wheel is shown according to some embodiments.

[0030] Figure 17 A detailed view of the sprocket section of the tower wheel is shown according to some embodiments.

[0031] Figure 18 An external view of a complete tower wheel assembly installed on a hub drive assembly according to some embodiments is shown.

[0032] Figure 19 A cross-sectional view of the complete tow wheel assembly mounted on the hub drive assembly and center axis is shown.

[0033] Figure 20 An internal view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0034] Figure 21 An internal detailed view of the sprocket section of the tower wheel is shown according to some embodiments.

[0035] Figure 22 An internal isometric view of the sprocket portion of the tower wheel according to some embodiments is shown.

[0036] Figure 23 A detailed view of the sprocket portion of the tow chock with a connecting part is shown according to some embodiments.

[0037] Figure 24 An internal view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0038] Figure 25 An internal detailed view of the sprocket section of the tower wheel is shown according to some embodiments.

[0039] Figure 26 An external detailed view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0040] Figure 27 A detailed view of the bottom interior of the sprocket section of the pawl, according to some embodiments, is shown.

[0041] Figure 28 An internal view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0042] Figure 29 An internal detailed view of the sprocket section of the tower wheel is shown according to some embodiments.

[0043] Figure 30 An external equidistant detail view of the small sprocket portion of the tower wheel is shown according to some embodiments.

[0044] Figure 31 An isometric view of the bottom interior of the small sprocket portion of the tower wheel, according to some embodiments, is shown.

[0045] Figure 32 A rear cross-sectional view of the sprocket portion of the tower wheel is shown according to some embodiments.

[0046] Figure 33 A detailed rear cross-sectional view of the small sprocket portion of the tower wheel is shown according to some embodiments. Detailed Implementation

[0047] Embodiments of the present invention relate to a tapered bicycle cassette with an integral sprocket assembly. Each annular portion of the sprocket individual is mechanically supported from the rear of the sprocket in an axial direction toward the central plane of the bicycle or in an internal radial direction toward the central axis of the bicycle cassette and hub. Axial and radial support sections alternate around the circumference of the sprocket, such that the entire sprocket is supported in either the axial or radial direction. In this manner, the chain drive load on the cassette is propagated throughout the entire cassette, and areas of high localized stress concentration on the cassette are eliminated.

[0048] The application of the conical bicycle sprocket and chainring structure will now be described in detail. For clarity, not all conventional features of the applications described herein are shown and described. It will be understood that in the development of any of these practical applications, various application-specific decisions can be made to achieve the developer's specific objectives, such as compliance with relevant application and business constraints, and these specific objectives will vary depending on the application and the developer. Furthermore, it will be understood that such development efforts are complex and time-consuming, but are nothing more than conventional engineering design inspired by this invention by those skilled in the art.

[0049] This application has been described with reference to specific embodiments in conjunction with details to facilitate understanding of the principles of construction and operation. References to specific embodiments and their details herein are not intended to limit the scope of the appended claims. It will be understood by those skilled in the art that changes may be made to the embodiments chosen for illustration without departing from the spirit and scope of the invention.

[0050] See now Figure 1 and Figure 2 This shows a complete tower wheel assembly 30 mounted on the right side of the rear bicycle hub 32 according to some embodiments.

[0051] Figure 3 The rear bicycle hub 32, including the hub drive assembly 34, is shown according to some embodiments before the complete tower wheel assembly 30 is installed.

[0052] like Figure 4 As shown, according to some embodiments, the hub drive assembly 34 includes a hub drive body 36, an outer hub drive bearing 38, a hub drive torque coupling 40, a hub drive tower wheel stop surface 41, a hub drive thread 42, and a right-end radial surface 44 of the hub drive.

[0053] like Figure 5 and Figure 6 As shown, according to some embodiments, the complete sprocket assembly 30 includes a sprocket large sprocket assembly 46, a sprocket small sprocket assembly 50, and a sprocket locking screw 52.

[0054] like Figure 7 and Figure 8 As shown, according to some embodiments, the sprocket assembly 50 includes a sprocket portion 54 and a sprocket sleeve 56. The sprocket sleeve 56 includes a sleeve flange 57, an outer surface 61 of the sleeve flange, an outer stepped surface 58 of the sleeve, and an inner stepped surface 59 of the sleeve.

[0055] Figure 9 The outer side of the sprocket portion 54 of the sprocket according to some embodiments is shown. The sprocket portion 54 includes 10 small sprockets 60a, 60b, 60c, 60d, 60e, 60f, 60g, 60h, 60i, and 60j, as well as a sprocket portion shaft clearance hole 62. Alternatively, the sprocket portion 54 may include more or fewer small sprockets.

[0056] Figure 10 The inner side of the sprocket portion 54 of the sprocket according to some embodiments is shown, including locking tabs 64a, 64b, 64c, 64d, 64e, and 64f, and a sprocket portion locking hole 68. The sprocket portion 54 also includes a first sprocket portion axial positioning surface 70, a second sprocket portion axial positioning surface 72, a first sprocket portion positioning hole 74, a second sprocket portion positioning hole 76, and a sprocket portion large end face 66.

[0057] like Figure 11 As shown, according to some embodiments, the tower wheel sprocket assembly 50 includes a small number of sprockets 60a, 60b, 60c, 60d, 60e, 60f, 60g, 60h, 60i and 60j.

[0058] Figure 12 The sprocket assembly 50 according to some embodiments is shown in... Figure 11 The cross-section at the arrow line shown. The small sprocket sleeve 56 of the tower wheel is assembled into the small sprocket part 54 of the tower wheel, such that the outer stepped surface 58 of the tower wheel fits into the positioning hole 74 of the first small sprocket part and the positioning hole 76 of the second small sprocket part.

[0059] Figure 13 An exploded view of a sprocket assembly 46 according to some embodiments is shown, which includes a sprocket portion 90 and a sprocket clamping screw 92. Figure 13 Most of the clamping element 138 and the locking screw receiving hole 78 are also shown.

[0060] Figure 14 An external isometric view of the sprocket portion 90 of the sprocket according to some embodiments is shown, including a clamping screw clearance orifice 140, clamping flexible slots 146a and 146b, and a clamping clearance slot 144. Figure 14Also shown are clamping protruding end face 148, clamping contact surface 150, and locking flanges 114a, 114b, 114c, 114d, 114e, and 114f. Figure 14 The diagram also shows the thread clearance orifice 152 and the sleeve flange positioning orifice 153.

[0061] Figure 15 An internal view of the large sprocket portion 90 is shown, with details of the large sprocket driver torque coupling 91 according to some embodiments. The large sprocket driver torque coupling 91 includes a driver torque coupling stop surface 160, torque coupling spline teeth 162, torque coupling spline recesses 164, and torque coupling spline end faces 166. The large sprocket portion 90 also includes a driver thread clearance orifice 168, a clamping inner end face 154, and a clamping contact surface 150.

[0062] Figure 16 An external isometric view of a sprocket portion 90 according to some embodiments is shown, wherein a circle surrounds a portion of the sprocket torque coupling of the sprocket portion 90. Figure 17 The following are shown according to some embodiments. Figure 16 An enlarged view of the area within the circle shown. (See attached image.) Figure 17 As shown, the large sprocket torsion coupling 91 shown in this section has several features, including a torque receiving surface 104, one of the locking flanges 114 (having a locking flange notch 106, a locking flange radial surface 108, and a locking flange inner surface 110), and a large sprocket portion offset protrusion 112. Figures 13 to 15 As shown, the features shown in this section can be repeated along the periphery of the large sprocket torsion wheel torque coupling. Additionally, one or more of the large sprocket torsion wheel torque couplings can include a locking screw receiving hole 78 with an inner surface 80 of a locking screw receiving hole.

[0063] Figure 18 An external view of the complete tower wheel assembly 30 installed in the hub drive assembly 34 according to some embodiments is shown.

[0064] Figure 19 The complete tower wheel assembly 30 and hub drive assembly 34 are shown in mounting and locking configurations according to some embodiments. Figure 18 The cross-section at the point indicated by the arrow. Figure 19As shown, the complete sprocket assembly 30 is mounted to the hub drive assembly 34, and they share a central axis 230. The hub drive assembly 34 includes a hub drive body 36. Two bearings, an outer hub drive bearing 38 and an inner hub drive bearing 39, mate in an inner hub drive bearing bore 43. A large sprocket portion 90 mates with the hub drive body 36 such that a large sprocket torque coupling 91 engages with the hub drive torque coupling 40, and the large sprocket coupling stop surface 93 contacts the hub drive sprocket stop surface 41. A sprocket miniature sprocket assembly 50 is mounted on the sprocket large sprocket assembly 46 and the hub drive assembly 34 such that a sprocket miniature sprocket sleeve 56 rests against the right-end radial surface 44 of the hub drive. The outer surface 61 of the sprocket miniature sprocket sleeve flange aligns with and is inside the sleeve flange positioning bore 153. The locking flange 108 is connected between the locking tongue 64 and the axial positioning surface 70 of the first small sprocket section.

[0065] Figure 20 An internal view of the sprocket portion 54 of the pawl according to some embodiments is shown, including the circled portion surrounding one of the locking tabs 64c. Figure 21 The diagram shows the location according to some embodiments. Figure 20 An enlarged internal view of the locking tab 64c within the circle. (See image.) Figure 21 As shown, the locking tongue 64c includes a torque driving surface 82 and an inner surface 84 of the tongue.

[0066] Figure 22 An isometric view of the interior front top of a torpedo wheel portion 54 according to some embodiments is shown, the view having a portion circled.

[0067] Figure 23 The following are shown according to some embodiments. Figure 22 A detailed view of the circled portion of the sprocket section 54. Figure 23 As shown, the sprocket portion 54 includes a connecting portion 200. Each connecting portion 200 includes a flat, disc-shaped portion 240 and a bell-shaped or swept-back curved portion 242. In some embodiments, the bell-shaped or swept-back curved portion 242 has a curved shape swept around a central axis.

[0068] Figure 24 An internal view of a sprocket portion 54 of a sprocket having a finely cut sprocket area 180, according to some embodiments, is shown.

[0069] Figures 25 to 27 Each of the following embodiments is shown separately. Figure 24 The fine cut area is shown in the 180° internal view, external isometric view, and internal isometric view. (Example) Figures 25 to 27As shown, the sprocket of the small sprocket portion 54 includes transition sections 182a, 182b, 182c, a radial support section 184, and an axial support section 186. The radial support section 184 is configured to support the sprocket from the inner radial direction of the sprocket towards the centerline axis of the bicycle cassette and hub. The axial support section 186 supports the sprocket in an axial direction towards the bicycle hub. In some embodiments, a plurality of radial support sections 184 and a plurality of axial support sections 186 alternate around some or all of the circumference of the sprocket in the small sprocket portion 54, such that each of the sprockets is supported entirely in either an axial or radial direction. In this way, each annular portion of the sprocket is mechanically supported either from the back of the sprocket towards the bicycle hub in an axial direction, or from the inner radial direction towards the centerline axis of the bicycle cassette and hub. The plurality of radial and axial support sections provide the benefits of spreading the chain drive load on the cassette throughout the cassette and removing areas of highly localized stress concentration from the individual sprocket.

[0070] As mentioned above, such as Figures 25 to 27 As shown, in some embodiments, this is achieved by alternating radial support sections 184 and axial support sections 186 around the sprocket. Repeating radial support sections 184 and axial support sections 186 are shown in... Figure 24 The alternating radial support sections 184 and axial support sections 186 mean that the number of support areas around each sprocket is even. In some embodiments, a typical sprocket can include 6 to 12 radial support sections 184 and corresponding 6 to 12 axial support sections 186. However, a sprocket can include more or fewer sections, as appropriately desired and for the desired weight-to-strength ratio of the sprocket.

[0071] The connection between the sprockets in the support section is achieved through multiple connection parts 200. Figure 32 This diagram shows a rear cross-sectional view of the small sprocket portion 54 of the cassette according to some embodiments, which is substantially similar to [the previous description] except for the portion circled in the circle. Figure 12 . Figure 33 The following are shown according to some embodiments. Figure 32 An enlarged view of the part circled in circles. For example... Figure 32 As shown, the connecting portion 200 that provides connection between the sprockets of the small sprocket portion 54 of the tower wheel includes a vertical section 202 of the connecting portion, a transition section 204 of the connecting portion, a rear attachment point 206 of the connecting portion, a radial undercut 210 of the connecting portion, and a side cut 208 of the connecting portion.

[0072] The radial transition between the first sprocket 220 and the second sprocket 222 is achieved by a vertical section 202 of the connecting portion, which spans a portion of the radial distance between the inner diameters of the first sprocket 220 and the second sprocket 222. The axial distance between the first sprocket 220 and the second sprocket 222 is occupied by an axial transition section 204 of the connecting portion. In some embodiments, the axial transition section 204 of the connecting portion includes a portion of a geometric torus that includes a portion of a circle rotating about the central axis 230 of the small sprocket portion 54 of the tower wheel.

[0073] In some implementations, transition sections 182a, 182b, and 182c can also employ different geometries to optimize the strength, stiffness, and weight of the tow pulley. In some implementations, this is achieved by generating the maximum possible transition cut radius 212 (see...). Figure 25 This generates the geometry of the transition partition so that large machining tools can be used to cut the feature.

[0074] The first sprocket 220 and the second sprocket 222 each include a plurality of teeth for engaging a drive chain (not shown). In some embodiments, the larger-diameter first sprocket 220 has one more tooth than the smaller-diameter second sprocket 222. For example, in some embodiments, the larger-diameter first sprocket 220 may include ten teeth, while the smaller-diameter second sprocket 222 may include nine teeth. In some embodiments, the larger-diameter first sprocket 220 includes at least two more teeth than the smaller-diameter second sprocket 222. In some embodiments, the portion 54 may have any number of sprockets, wherein the sprocket with the largest diameter is adjacent to the inner side of the portion 54, the sprocket with the smallest diameter is adjacent to the outer side of the portion 54, and each sprocket from the innermost sprocket to the outermost sprocket has a diameter (and / or number of teeth) that gradually decreases from the previous sprocket.

[0075] In some embodiments, the thickness of the vertical section 202 of the connecting portion and the thickness of the axial transition section 204 of the connecting portion are the same. Alternatively, the thickness of the vertical section 202 of the connecting portion and the thickness of the axial transition section 204 of the connecting portion are different. In particular, in some embodiments, at each sprocket of the small sprocket portion 54, the thickness of the vertical section 202 of the connecting portion and the thickness of the axial transition section 204 of the connecting portion are the same. In some embodiments, one or more holes are cut between the repeating radial support sections 184 and axial support sections 186 of the first sprocket 220 and the second sprocket 220 to reduce the weight of the cascade. In particular, the desired thickness and transition cut radius 212 of the vertical section 202 of the connecting portion and the axial transition section 204 of the connecting portion can be selected to provide appropriate strength, stiffness, and weight for the entire cascade structure.

[0076] As described above, according to some embodiments, the small sprocket portion 54 of the tow sprocket exhibits one or more connecting portions 200 for connecting multiple sprockets. In some embodiments, the large sprocket portion 46 / 90 of the tow sprocket may include one or more connecting portions 200. Specifically, in some embodiments, one or both of the large sprocket portion 46 / 90 and the small sprocket portion 54 of the tow sprocket include one or more connecting portions 200.

[0077] Figure 28 An internal view of an alternative sprocket portion 190 of the cassette according to another embodiment is shown, with a detailed cut-out view area 192. The sprocket portion 190 is substantially similar to the cassette portion 54 of the cassette, except for the differences described herein. Figures 29 to 31 They are shown respectively Figure 28 The detailed cut view area 192 shown includes an internal magnified view, an external magnified perspective view, and an internal magnified perspective view. (See attached image.) Figures 29 to 31 As shown, the small sprocket portion 190 can include five transition sections 194a, 194b, and 194c, a radial support section 196, and an axial support section 198, similar to the above. Figures 25 to 27 Those described herein. Transition partitions 194a and 194b are represented as areas circled in detail. In some embodiments, a smaller tool is used to cut the geometry of the transition partitions to form shapes as shown in transition partitions 194a, 194b, and 194c, in which straight edges with small radii form the transition features.

[0078] The assembly and operation of the cassette is disclosed in U.S. Patent Application Serial No. 16 / 104,635 ('635 application), filed August 17, 2018, entitled "Bicycle Cassette with Clamping Connection," which is incorporated herein by reference. However, it should be noted that the structural details described herein can be applied to various cassette attachment methods, such as those disclosed in Braedt's U.S. Patent Application Serial No. 13 / 307,331, Earle's US14 / 923,343, and Vergara's PCT Publication No. W 02018 / 041409, as well as other methods of attaching a cassette having multiple sprockets made of a single piece of material to a bicycle hub.

[0079] The complete cassette assembly 30 can be assembled onto the rear bicycle hub 32 using common tools familiar to bicycle mechanics and others knowledgeable in bicycle construction and assembly. In some embodiments, the tools required for the preferred assembly shown in the figures are hex keys or other tools that engage with the cassette locking screw 52 and the cassette clamping screw 92. Assembly can be further simplified by using the same tool interface on the screws, making one tool sufficient to assemble or install or remove the cassette assembly from the hub 32.

[0080] To assemble the complete cassette assembly 30, the cassette chainring assembly 46 slides towards the left end of the rear bicycle hub 32 onto the radial surface 44 of the right end of the hub driver until the chainring driver torque coupling 91 engages with the hub driver torque coupling 40. The top surface 93 of the chainring coupling presses against the top surface 41 of the hub driver cassette.

[0081] Once the sprocket assembly 46 is fully engaged with the hub, use a hex wrench or other tool to tighten the sprocket clamping screw 92 to the appropriate torque value. Applying torque to the screw closes the clamping clearance slot 144 and creates pressure between the clamping contact surface 150 and the radial surface 44 at the right end of the hub drive, thereby preventing the sprocket assembly 46 from moving on the hub drive body 36.

[0082] In some embodiments, the threaded clearance aperture 152 on the large sprocket portion 90 allows the large sprocket portion 90 to be assembled to the hub drive body 36 without using the hub drive thread 42. In this embodiment, the thread 42 of the hub drive body 36 can be omitted.

[0083] After tightening the large sprocket clamping screw 92, the tower wheel small sprocket assembly 50 can be installed. The inner stepped surface 59 of the sleeve is aligned with the radial surface 44 of the right end of the hub drive, and the locking tongue 64 is aligned with the locking flange 114.

[0084] After proper alignment, the cassette chainring assembly 50 slides toward the rear bicycle hub 32 until the axial locating surface 72 of the second chainring portion contacts the inner surface 110 of the locking flange. Once the cassette chainring assembly 50 is in place, it can be rotated clockwise relative to the cassette chainring assembly 46 by hand or with a tool until the torque drive surface 82 contacts the torque receiving surface 104. At this point, the cassette chainring assembly 50 no longer moves to the left along the hub axis because the locking flange 114 is accommodated between the axial locating surface 70 of the first chainring portion and the locking tongue 64.

[0085] Next, the sprocket locking screw 52 is inserted through the locking hole 68 of the small sprocket portion into the locking screw receiving hole 78 and tightened using a suitable tool. Once the appropriate torque is applied to the screw, the sprocket 30 is fully installed.

[0086] To disassemble the small sprocket assembly 50 from the large sprocket assembly 46, simply reverse the order of the assembly instructions.

[0087] This paper describes a tapered bicycle cassette with an integral sprocket assembly. In operation, each annular portion of the sprocket individual within the cassette body is mechanically supported either axially toward the bicycle hub from the rear of the sprocket or radially toward the centerline of the cassette and hub. Axial and radial support zones alternate around the circumference of the sprocket, ensuring the entire sprocket is supported axially or radially. In this manner, the chain-driven load on the cassette is distributed throughout the entire cassette, eliminating areas of high localized stress concentration.

[0088] In particular, when cutting or forming bicycle tow wheels, as mentioned above, the material thickness and cut of the connecting parts and holes can be selected to provide the tow wheel structure with ideal strength, stiffness, and weight. Furthermore, if cutting operations other than machining (such as electrical discharge machining) are used in the manufacturing process, the shape of these openings can be extended to include sharper edges or non-circular curves, such as spline curves. While this is primarily described based on the removal of material from a monolithic base material using a variety of known cutting processes, tow wheels can also be readily formed using any number of known additive manufacturing processes, such as casting, 3D printing, or laser sintering.

[0089] Furthermore, the thickness of each support section and the overlap length between support sections in the transition region can be optimized for any given cassette configuration to provide sufficient strength and stiffness for the application. For example, a cassette designed for use with e-bikes may require thicker supports and greater overlap between support areas. Thus, the tapered bicycle cassette sprocket structure described herein offers numerous advantages.

[0090] This invention has been described in detail with reference to specific embodiments to aid in understanding the construction and operating principles of the invention. The description of these specific embodiments and their details herein is not intended to limit the scope of the appended claims. Those skilled in the art will understand that changes may be made to the embodiments chosen for illustration without departing from the spirit and scope of the invention.

Claims

1. A conical bicycle cassette, comprising: Tower wheel locking screw; A large sprocket assembly having one or more large sprockets; as well as An integral small sprocket assembly, detachably connected to the large sprocket assembly via the sprocket locking screw, the integral small sprocket assembly having a central axis and including: A first sprocket has a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members, wherein the plurality of first radial support members are circumferentially offset from the plurality of first axial support members. The second sprocket has a plurality of outwardly extending second gear teeth, a second inner circumference smaller than the first inner circumference opposite to the second gear teeth, a plurality of second radial support members, and a plurality of second axial support members, wherein the plurality of radial support members are circumferentially offset from the plurality of second axial support members; and The third sprocket has a plurality of outwardly extending third gear teeth and a third inner circumference that is larger than the first inner circumference and is opposite to the third gear teeth; Wherein, the first radial support member extends radially from the inner circumference toward the central axis, bends toward the second sprocket, and is connected to the second sprocket at the level of the second inner circumference; and further, wherein the first axial support member extends radially toward the third sprocket in an axial direction parallel to the central axis, bends toward the third sprocket, and is connected to the third inner circumference of the third sprocket.

2. The bicycle cassette wheel according to claim 1, wherein, Each of the plurality of first radial support members and the plurality of first axial support members has one or more processed windows.

3. The bicycle cassette wheel according to claim 1, wherein, The positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternate, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members.

4. The bicycle cassette wheel according to claim 1, wherein, The number of teeth on the first gear is greater than the number of teeth on the second gear and less than the number of teeth on the third gear.

5. The bicycle cassette wheel according to claim 1, wherein, In a direction aligned with the central axis, the left and right profiles of each of the plurality of first radial support members and the plurality of second radial support members, as well as the left and right profiles of each of the plurality of first axial support members and the plurality of second axial support members, are curved.

6. The bicycle cassette wheel according to claim 1, wherein, In the direction aligned with the central axis, the left and right sides of each of the plurality of first radial support members and the plurality of second radial support members are mostly straight, and the left and right sides of each of the plurality of first axial support members and the plurality of second axial support members are both straight.

7. The bicycle cassette wheel according to claim 1, wherein, The third sprocket is the largest sprocket in the integral small sprocket assembly, and further, the third sprocket has a plurality of tabs that extend radially from the third inner circumference in the same plane as the third gear teeth in opposite directions.

8. The bicycle cassette wheel according to claim 7, wherein, The large sprocket assembly includes a plurality of locking flanges, each having a notch, and further wherein each of the tongues is positioned within one of the notches to engage the large sprocket assembly with the integral small sprocket assembly.

9. The bicycle cassette wheel according to claim 7, wherein, Each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion.

10. The bicycle cassette wheel according to claim 9, wherein, The curved portion is the shape of a curve extending around the central axis.

11. An integral sprocket assembly having a central axis, the integral sprocket assembly comprising: A first sprocket has a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members, wherein the plurality of first radial support members are circumferentially offset from the plurality of first axial support members. The second sprocket has a plurality of outwardly extending second gear teeth, a second inner circumference smaller than the first inner circumference opposite to the second gear teeth, a plurality of second radial support members, and a plurality of second axial support members, wherein the plurality of radial support members are circumferentially offset from the plurality of second axial support members; as well as The third sprocket has a plurality of outwardly extending third gear teeth and a third inner circumference that is larger than the first inner circumference and is opposite to the third gear teeth. Wherein, the first radial support member extends radially from the inner circumference toward the central axis, bends toward the second sprocket, and is connected to the second sprocket at the level of the second inner circumference; and further, wherein the first axial support member extends radially toward the third sprocket in an axial direction parallel to the central axis, bends toward the third sprocket, and is connected to the third inner circumference of the third sprocket.

12. The integral sprocket assembly according to claim 11, wherein, Each of the plurality of first radial support members and the plurality of first axial support members has one or more processed windows.

13. The integral sprocket assembly according to claim 11, wherein, The positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternate, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members.

14. The integral sprocket assembly according to claim 11, wherein, The number of teeth on the first gear is greater than the number of teeth on the second gear and less than the number of teeth on the third gear.

15. The integral sprocket assembly according to claim 11, wherein, In a direction aligned with the central axis, the left and right profiles of each of the plurality of first radial support members and the plurality of second radial support members, as well as the left and right profiles of each of the plurality of first axial support members and the plurality of second axial support members, are curved.

16. The integral sprocket assembly according to claim 11, wherein, In the direction aligned with the central axis, the left and right sides of each of the plurality of first radial support members and the plurality of second radial support members are mostly straight, and the left and right sides of each of the plurality of first axial support members and the plurality of second axial support members are both straight.

17. The integral sprocket assembly according to claim 11, wherein, The third sprocket is the largest sprocket in the integral sprocket assembly, and further, the third sprocket has a plurality of tabs that extend radially from the third inner circumference in opposite directions within the same plane as the third gear teeth.

18. The integral sprocket assembly according to claim 11, wherein, Each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion.

19. The integral sprocket assembly according to claim 18, wherein, The curved portion is the shape of a curve extending around the central axis.

20. A method for providing a conical bicycle cassette wheel, the method comprising: Provide large sprocket assemblies with one or more large sprockets; as well as The integral small sprocket assembly is detachably connected to the large sprocket assembly using a sprocket locking screw, wherein the integral small sprocket assembly has a central axis and includes: A first sprocket has a plurality of outwardly extending first gear teeth, a first inner circumference opposite to the first gear teeth, a plurality of first radial support members, and a plurality of first axial support members, wherein the plurality of first radial support members are circumferentially offset from the plurality of first axial support members. A second sprocket, the second sprocket having a plurality of outwardly extending second gear teeth, a second inner circumference smaller than the first inner circumference opposite to the second gear teeth, a plurality of second radial support members, and a plurality of second axial support members, wherein the plurality of radial support members are circumferentially offset from the plurality of second axial support members; and The third sprocket has a plurality of outwardly extending third gear teeth and a third inner circumference larger than the first inner circumference opposite to the third gear teeth. Wherein, the first radial support member extends radially from the inner circumference toward the central axis, bends toward the second sprocket, and is connected to the second sprocket at the level of the second inner circumference; and further, wherein the first axial support member extends radially toward the third sprocket in an axial direction parallel to the central axis, bends toward the third sprocket, and is connected to the third inner circumference of the third sprocket.

21. The method according to claim 20, wherein, Each of the plurality of first radial support members and the plurality of first axial support members has one or more processed windows.

22. The method according to claim 20, wherein, The positions of the plurality of first radial support members and the plurality of first axial support members on the first sprocket are alternate, such that along the first inner circumference, each of the first radial support members is crossed by two of the first axial support members, and each of the first axial support members is crossed by two of the first radial support members.

23. The method of claim 20, wherein, The number of teeth on the first gear is greater than the number of teeth on the second gear and less than the number of teeth on the third gear.

24. The method of claim 20, wherein, In a direction aligned with the central axis, the left and right profiles of each of the plurality of first radial support members and the plurality of second radial support members, as well as the left and right profiles of each of the plurality of first axial support members and the plurality of second axial support members, are curved.

25. The method of claim 20, wherein, In the direction aligned with the central axis, the left and right sides of each of the plurality of first radial support members and the plurality of second radial support members are mostly straight, and the left and right sides of each of the plurality of first axial support members and the plurality of second axial support members are both straight.

26. The method of claim 20, wherein, The third sprocket is the largest sprocket in the integral small sprocket assembly, and further, the third sprocket has a plurality of tabs that extend radially from the third inner circumference in the same plane as the third gear teeth in opposite directions.

27. The method according to claim 26, wherein, The large sprocket assembly includes a plurality of locking flanges, each having a notch, and the method further includes sliding each of the flanges into one of the notches before screwing in the sprocket locking screw, so as to connect the large sprocket assembly to the integral small sprocket assembly.

28. The method according to claim 20, wherein, Each of the first radial support members and each of the first axial support members includes a flat portion and a curved portion.

29. The method according to claim 28, wherein, The curved portion is the shape of a curve extending around the central axis.

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