Crank assembly for human powered vehicle

Abstract

A crank assembly comprises a crank arm, a front sprocket unit, and a plurality of chain-drop control protrusions. The plurality of chain-drop control protrusions is configured to inhibit a drive chain from getting into a space provided radially inwardly from the plurality of chain-drop control protrusions and between the crank arm and the front sprocket unit in an axial direction. The plurality of chain-drop control protrusions is configured to be provided to at least one of an axially inwardly facing crank-surface of the crank arm and an axially outwardly facing sprocket-surface of the front sprocket unit. The plurality of chain-drop control protrusions is spaced apart from each other in a circumferential direction with respect to the rotational center axis.

Description

[Technical Field]

[0001] This invention relates to a crank assembly for a human-powered vehicle. [Previous Technology]

[0002] A human-powered vehicle includes a crank unit. The crank unit includes an arm and a sprocket. A pedal is attached to the arm. The sprocket can rotate with the arm. A chain engages with the sprocket teeth. The chain can disengage from the sprocket teeth toward the arm. When the chain disengages from the sprocket teeth, it is preferable to limit the chain from falling into a space provided between the sprocket and the arm. [Summary of the Invention]

[0003] According to a first aspect of the present invention, a crank assembly for a human-powered vehicle includes a crank arm, a front sprocket unit, and a plurality of chain slip control protrusions. The crank arm has an axially outward crank surface and an axially inward crank surface disposed on the opposite side of the axially outward crank surface in an axial direction relative to a rotational center axis of the crank assembly. The axially inward crank surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when the crank assembly is mounted to the human-powered vehicle. The front sprocket unit has an axially outward sprocket surface and an axially inward sprocket surface disposed on the opposite side of the axially outward sprocket surface in the axial direction. The axially inward sprocket surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when mounted. The front sprocket unit includes a sprocket body and a plurality of sprocket teeth extending radially outward from the sprocket body in a radial direction relative to a rotational center axis. The plurality of chain slippage control protrusions are configured to prevent a drive chain from falling into a space located radially inward from the plurality of chain slippage control protrusions and in the axial direction between the crank arm and the front sprocket unit. The plurality of chain slippage control protrusions are configured to be disposed on at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit. The plurality of chain slippage control protrusions are spaced apart from each other in a circumferential direction relative to the rotation center axis.

[0004] In respect of the crank assembly according to the first state, the plurality of chain disengagement control protrusions can reliably prevent the drive chain from falling into the space provided between the front sprocket unit and the crank arm when the drive chain disengages from the plurality of sprocket teeth of the front sprocket unit.

[0005] According to a second embodiment of the present invention, the crank assembly according to the first embodiment further includes an electrical component disposed at a position radially inward from the plurality of chain detachment control protrusions to the crank arm.

[0006] Regarding the crank assembly according to the second configuration, the plurality of chain detachment control protrusions can reduce interference between the drive chain and the electrical component when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit. Therefore, the electrical component can be protected from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0007] According to a third aspect of the present invention, the crank assembly of the second aspect is configured such that the electrical component includes a force sensor.

[0008] In the case of the crank assembly according to the third state, the plurality of chain detachment control protrusions can protect the force sensor from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0009] According to a fourth embodiment of the present invention, the crank assembly according to the second or third embodiment further includes a cover member configured to attach to the axially inward crank surface of the crank arm to cover one of the electrical components in an assembled state of the crank assembly.

[0010] Regarding the crank assembly according to the fourth configuration, the plurality of chain detachment control protrusions can protect the cover member from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit. Furthermore, the cover member can reliably protect the electrical components from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0011] According to a fifth embodiment of the present invention, the crank assembly of the fourth embodiment is configured such that the cover member is made of a non-metallic material.

[0012] Regarding the crank assembly according to the fifth configuration, the plurality of chain detachment control protrusions can protect the cover member made of the non-metallic material from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit. Furthermore, the cover member can reliably protect the electrical components from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit, while simultaneously reducing the weight of the crank assembly.

[0013] According to a sixth embodiment of the present invention, the crank assembly of any one of the first to fifth embodiments is configured such that the plurality of chain slip control protrusions are at least partially arranged radially inward from the sprocket teeth.

[0014] In respect of the crank assembly according to the sixth state, the plurality of chain detachment control protrusions can reliably prevent the drive chain from falling into the space provided between the front sprocket unit and the crank arm when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0015] According to a seventh embodiment of the present invention, the crank assembly of any one of the first to sixth embodiments is configured such that when viewed from the axial direction, the plurality of chain detachment control protrusions overlap with the crank arm.

[0016] With respect to the crank assembly of the seventh state, the drive chain can be reliably prevented from getting stuck in the space between the front sprocket unit and the crank arm when the drive chain disengages from the plurality of sprocket teeth of the front sprocket unit, while reasonably maintaining one of the appearances of the crank assembly.

[0017] According to an eighth state of the present invention, the crank assembly of any one of the first to seventh states is configured such that the total number of one of the plurality of chain detachment control protrusions is equal to or greater than 3.

[0018] In relation to the crank assembly of the eighth state, the plurality of chain detachment control protrusions can reliably prevent the drive chain from falling into the space provided between the front sprocket unit and the crank arm when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0019] According to a ninth aspect of the present invention, a crank assembly for a human-powered vehicle includes a crank arm, a front sprocket unit, and at least one chain slippage control member. The crank arm has an axially outward crank surface and an axially inward crank surface disposed on the opposite side of the axially outward crank surface in an axial direction relative to a rotational axis of the crank assembly. The axially inward crank surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when the crank assembly is mounted to the human-powered vehicle. The crank arm has a maximum circumferential crank width in a circumferential direction relative to the rotational axis. The front sprocket unit has an axially outward sprocket surface and an axially inward sprocket surface disposed on the opposite side of the axially outward sprocket surface in the axial direction. The axially inward sprocket surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when mounted. The front sprocket unit includes a sprocket body and a plurality of sprocket teeth extending radially outward from the sprocket body in a radial direction relative to one of the rotational central axes. At least one chain slippage control member is configured to prevent a drive chain from becoming trapped in a space located radially inward from the at least one chain slippage control member and in the axial direction between the crank arm and the front sprocket unit. The at least one chain slippage control member is configured to be disposed to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit. The at least one chain slippage control member has a proximal end and a free distal end. The proximal end is attached to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit. The free distal end is arranged radially outward from the proximal end relative to the rotational central axis. The at least one chain slippage control member has a maximum circumferential member width in the circumferential direction. The maximum circumferential member width is equal to or less than the maximum circumferential crank width.

[0020] In respect of the crank assembly according to the ninth state, the at least one chain detachment control member can limit the drive chain from falling into the space between the front sprocket unit and the crank arm when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit, while reasonably maintaining one of the appearances of the crank assembly.

[0021] According to a tenth embodiment of the present invention, the crank assembly of the ninth embodiment is configured such that each of the plurality of sprocket teeth has a circumferential tooth width defined between the center points of adjacent tooth roots in the circumferential direction. The maximum circumferential member width is equal to or greater than the circumferential tooth width.

[0022] In respect of the crank assembly according to the tenth state, the at least one chain slippage control member can reliably limit the drive chain from getting stuck in the space between the front sprocket unit and the crank arm when the drive chain slips from the plurality of sprocket teeth of the front sprocket unit.

[0023] According to an eleventh aspect of the present invention, the crank assembly of the tenth aspect is configured such that the width of the maximum circumferential member is equal to or greater than twice the width of the circumferential tooth.

[0024] In respect of the crank assembly according to the eleventh configuration, the at least one chain slippage control member can more reliably limit the drive chain from getting stuck in the space between the front sprocket unit and the crank arm when the drive chain slips from the plurality of sprocket teeth of the front sprocket unit.

[0025] According to a twelfth embodiment of the present invention, the crank assembly according to the tenth or eleventh embodiment is configured such that the proximal end of the at least one chain slip control member has a maximum circumferential proximal end width in the circumferential direction. The maximum circumferential proximal end width is equal to or greater than the circumferential tooth width.

[0026] In respect of the crank assembly according to the twelfth configuration, the proximal end of the at least one chain slip control member can be reliably fastened to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit.

[0027] According to a thirteenth embodiment of the present invention, the crank assembly according to any one of the tenth to twelfth embodiments is configured such that the free distal end of the at least one chain slip control member has a maximum circumferential distal end width in the circumferential direction. The maximum circumferential distal end width is equal to or greater than the circumferential tooth width.

[0028] In respect of the crank assembly according to the thirteenth configuration, the free distal end of the at least one chain detachment control member can more reliably limit the drive chain from getting stuck in the space between the front sprocket unit and the crank arm when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0029] According to one of the fourteenth embodiments of the present invention, the crank assembly of any one of the ninth to thirteenth embodiments is configured such that the free distal end is arranged radially outward from the plurality of sprocket teeth.

[0030] In respect of the crank assembly according to the fourteenth configuration, the at least one chain slippage control member can reliably prevent the drive chain from getting stuck in the space between the front sprocket unit and the crank arm when the drive chain slips from the plurality of sprocket teeth of the front sprocket unit.

[0031] According to a fifteenth embodiment of the present invention, the crank assembly according to any one of the ninth to fourteenth embodiments further includes an electrical component disposed at a position radially inward from the at least one chain slip control member to the crank arm.

[0032] Regarding the crank assembly according to the fifteenth configuration, the at least one chain slippage control member can reduce interference between the drive chain and the electrical component when the drive chain slips off from the plurality of sprocket teeth of the front sprocket unit. Therefore, the electrical component can be protected from the influence of the drive chain when the drive chain slips off from the plurality of sprocket teeth of the front sprocket unit.

[0033] According to a sixteenth embodiment of the present invention, the crank assembly according to the fifteenth embodiment is configured such that the electrical component includes a force sensor.

[0034] In respect of the crank assembly according to the sixteenth configuration, the at least one chain slippage control member can protect the force sensor from the influence of the drive chain when the drive chain slips from the plurality of sprocket teeth of the front sprocket unit.

[0035] According to a seventeenth embodiment of the present invention, the crank assembly according to the fifteenth or sixteenth embodiment further includes a cover member configured to attach to the axially inward crank surface of the crank arm to cover one of the electrical components in an assembled state of the crank assembly.

[0036] Regarding the crank assembly according to the seventeenth configuration, the at least one chain detachment control member can protect the cover member from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit. Furthermore, the cover member can reliably protect the electrical components from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit.

[0037] According to one eighteenth embodiment of the present invention, the crank assembly of the seventeenth embodiment is configured such that the cover member is made of a non-metallic material.

[0038] Regarding the crank assembly according to the eighteenth configuration, the at least one chain detachment control member can protect the cover member made of non-metallic material from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit. Furthermore, the cover member can reliably protect the electrical components from the influence of the drive chain when the drive chain detaches from the plurality of sprocket teeth of the front sprocket unit, while simultaneously reducing the weight of the crank assembly.

[0039] According to a nineteenth embodiment of the present invention, a crank assembly for a human-powered vehicle includes a crank arm, a front sprocket unit, and at least one chain slippage control member. The crank arm has an axially outward crank surface and an axially inward crank surface disposed on the opposite side of the axially outward crank surface in an axial direction relative to a rotational axis of the crank assembly. The axially inward crank surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when the crank assembly is mounted to the human-powered vehicle. The crank arm has a maximum circumferential crank width in a circumferential direction relative to the rotational axis. The front sprocket unit has an axially outward sprocket surface and an axially inward sprocket surface disposed on the opposite side of the axially outward sprocket surface in the axial direction. The axially inward sprocket surface is configured to face the axial center plane of the human-powered vehicle in the axial direction when mounted. The front sprocket unit includes a sprocket body and a plurality of sprocket teeth extending radially outward from the sprocket body in a radial direction relative to one of the rotation center axes. At least one chain slippage control member is configured to prevent a drive chain from falling into a space disposed radially inward from the at least one chain slippage control member and located in the axial direction between the crank arm and the front sprocket unit. The at least one chain slippage control member is configured to be disposed to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit. The at least one chain slippage control member has a proximal end and a free distal end. The proximal end is attached at a plurality of points to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit. The at least one chain slippage control member has a maximum circumferential member width in the circumferential direction. The maximum circumferential member width is equal to or less than the maximum circumferential crank width.

[0040] Regarding the crank assembly according to the nineteenth embodiment, the at least one chain slippage control member can prevent the drive chain from falling into the space between the front sprocket unit and the crank arm when the drive chain slips from the plurality of sprocket teeth of the front sprocket unit, while reasonably maintaining one appearance of the crank assembly. Furthermore, the proximal end of the at least one chain slippage control member can be reliably fastened to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit.

[0041] According to one of the twentieth embodiments of the present invention, the crank assembly according to the nineteenth embodiment is configured such that each of the plurality of sprocket teeth has a circumferential tooth width defined between the center points of adjacent tooth roots in the circumferential direction. The maximum circumferential member width is equal to or greater than the circumferential tooth width.

[0042] In respect of the crank assembly according to the twentieth state, the proximal end of the at least one chain slip control member can be reliably fastened to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit.

Implementation Method

[0077] Several embodiments will now be described with reference to the accompanying drawings, wherein the same element symbols in all the various figures indicate corresponding or identical elements. First Embodiment

[0078] As shown in Figure 1, a crank assembly 10 for a human-powered vehicle 2 is rotatable about a rotational central axis A1 relative to a vehicle body 2A. The crank assembly 10 is configured to rotate about the rotational central axis A1 relative to the vehicle body 2A in a rotational transmission direction D1 during pedaling.

[0079] In this invention, a human-powered vehicle is a vehicle propelled by at least one human power source, including a user (i.e., a rider) riding the human-powered vehicle. Human-powered vehicles include various types of bicycles, such as a mountain bike, a road bike, a city bike, a cargo bike, a hand-cranked bicycle, and a recumbent bicycle. Furthermore, human-powered vehicles include electric bicycles (E-bikes). Electric bicycles include electric-assisted bicycles configured to assist in vehicle propulsion using an electric motor. However, the total number of wheels in a human-powered vehicle is not limited to two. For example, a human-powered vehicle includes a vehicle having one wheel or three or more wheels. Human-powered vehicles, in particular, do not include vehicles that use only an internal combustion engine as a power source. Generally, light road vehicles, including those that do not require a road driving license, are considered human-powered vehicles.

[0080] In this application, the following directional terms "forward," "rearward," "forward," "backward," "left," "right," "lateral," "upward," and "downward," as well as any other similar directional terms, refer to the direction determined based on a user (e.g., a rider) facing a handlebar or steering mechanism in a standard position within the human-powered vehicle 2 (e.g., on a saddle or seat). Therefore, when used to describe the crank assembly 10 or other components, these terms should be interpreted relative to a human-powered vehicle 2 equipped with the crank assembly 10 or other components used in an upright riding position on a horizontal plane.

[0081] As shown in Figure 1, the crank assembly 10 for the human-powered vehicle 2 includes a crank arm 12 and a front sprocket unit 14. The crank assembly 10 includes a crankshaft 16. The crankshaft 16 extends along a rotational axis A1. The crankshaft 16 is configured to be rotatably supported by the vehicle body 2A about the rotational axis A1. The crank arm 12 is fixed to the crankshaft 16 to rotate with the crankshaft 16 relative to the vehicle body 2A about the rotational axis A1. The crank assembly 10 includes an additional crank arm fixed to the crankshaft 16. In this embodiment, the crank arm 12 is a right crank arm. The additional crank arm is a left crank arm. However, as needed and / or desired, the configuration of the crank arm 12 may be applied to a left crank arm.

[0082] The front sprocket unit 14 is configured to engage with a drive chain 4. The front sprocket unit 14 is fixed to at least one of the crank arm 12 and the crank shaft 16. In a first embodiment, the front sprocket unit 14 is directly fixed to the crank arm 12 by a plurality of fasteners 17. However, as needed and / or desired, the front sprocket unit 14 may be directly fixed to the crank shaft 16 or both the crank arm 12 and the crank shaft 16.

[0083] As shown in Figure 2, the front sprocket unit 14 includes a first front sprocket 18 and a second front sprocket 20. The first front sprocket 18 and the second front sprocket 20 are fixed to the crank arm 12 by a plurality of fasteners 17.

[0084] The first front sprocket 18 includes a sprocket body 18A and a plurality of sprocket teeth 18B. That is, the front sprocket unit 14 includes a sprocket body 18A and a plurality of sprocket teeth 18B. The sprocket body 18A of the first front sprocket 18 is fixed to the crank arm 12 by a plurality of fasteners 17. The plurality of sprocket teeth 18B extend radially outward from the sprocket body 18A in a radial direction relative to the rotation center axis A1.

[0085] The first front sprocket 18 may also refer to a front sprocket 18. The sprocket body 18A may also refer to a first sprocket body 18A. The sprocket tooth may also refer to a first sprocket tooth.

[0086] The second front sprocket 20 includes a second sprocket body 20A and a plurality of second sprocket teeth 20B. The second sprocket body 20A of the second front sprocket 20 is fixed to the crank arm 12 by a plurality of fasteners 17. The plurality of second sprocket teeth 20B extend radially outward from the second sprocket body 20A in a radial direction relative to the rotation center axis A1.

[0087] The first front sprocket 18 has a first sprocket outer diameter DM11. The second front sprocket 20 has a second sprocket outer diameter DM12. The first sprocket outer diameter DM11 is larger than the second sprocket outer diameter DM12. However, as needed and / or desired, the first sprocket outer diameter DM11 may be smaller than the second sprocket outer diameter DM12. As needed and / or desired, the second front sprocket 20 may be omitted from the front sprocket unit 14.

[0088] As shown in Figure 2, the crank arm 12 includes a plurality of coupling components 22. As shown in Figure 3, the plurality of coupling components 22 are disposed between the first front sprocket 18 and the second front sprocket 20 in an axial direction D2 relative to the rotation center axis A1 of the crank assembly 10.

[0089] As shown in Figure 4, the front sprocket unit 14 includes a plurality of receiving members 24. As shown in Figure 3, each receiving member 24 includes a threaded hole 24A. The fastener 17 includes an external thread 17A. The external thread 17A engages with the threaded hole 24A.

[0090] As shown in Figure 5, the crank arm 12 has an axially outward crank surface 12A and an axially inward crank surface 12B. The axially inward crank surface 12B is disposed on the opposite side of the axially outward crank surface in the axial direction D2 relative to the rotation center axis A1 of the crank assembly 10.

[0091] The axially inward crank surface 12B is configured to face the axial center plane CP of the human-powered vehicle 2 in the axial direction D2 during the mounting state in which the crank assembly 10 is mounted to one of the human-powered vehicles 2. The axial center plane CP is perpendicular to the rotation center axis A1. For example, the axial center plane CP is defined to divide the axial width of the vehicle body 2A in the axial direction D2.

[0092] The front sprocket unit 14 has an axially outward sprocket surface 14A and an axially inward sprocket surface 14B. The axially inward sprocket surface 14B is disposed on the opposite side of one of the axially outward sprocket surfaces 14A in the axial direction D2. The axially inward sprocket surface 14B is configured to face the axial center plane CP of the manual vehicle 2 in the axial direction D2 in the installed state.

[0093] The axially inward crank surface 12B is configured to face the forward sprocket unit 14 in the axial direction D2. The axially inward crank surface 12B is configured to face the axially outward sprocket surface 14A of the forward sprocket unit 14 in the axial direction D2.

[0094] The axially inward crank surface 12B is spaced apart from the front sprocket unit 14 in the axial direction D2. The axially inward crank surface 12B is spaced apart from the axially outward sprocket surface 14A of the front sprocket unit 14 in the axial direction D2.

[0095] As shown in FIG6, the crank assembly 10 for the human-powered vehicle 2 includes at least one chain detachment control protrusion 30. In this embodiment, the at least one chain detachment control protrusion 30 includes a plurality of chain detachment control protrusions 30. That is, the crank assembly 10 for the human-powered vehicle 2 includes a plurality of chain detachment control protrusions 30.

[0096] The total number of one of the plurality of chain detachment control protrusions 30 is equal to or greater than 3. In this embodiment, the total number of the plurality of chain detachment control protrusions 30 is equal to 3. However, as needed and / or desired, the total number of the plurality of chain detachment control protrusions 30 may be greater than or equal to 2.

[0097] As shown in Figure 5, at least one chain slippage control protrusion 30 is configured to prevent the drive chain 4 from falling into a space SP located radially inward from the at least one control protrusion and in the axial direction D2 between the crank arm 12 and the front sprocket unit 14. A plurality of chain slippage control protrusions 30 are configured to prevent the drive chain 4 from falling into the space SP located radially inward from the plurality of chain slippage control protrusions 30 and in the axial direction D2 between the crank arm 12 and the front sprocket unit 14.

[0098] At least one chain slippage control protrusion 30 is configured to be disposed at least one of the crank arm 12 and the front sprocket unit 14. A plurality of chain slippage control protrusions 30 are configured to be disposed at least one of the crank arm 12 and the front sprocket unit 14.

[0099] At least one chain slippage control protrusion 30 is configured to be disposed on at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14. A plurality of chain slippage control protrusions 30 are configured to be disposed on at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14.

[0100] In this embodiment, a plurality of chain slippage control protrusions 30 are configured to be disposed on the crank arm 12 and the front sprocket unit 14. A plurality of chain slippage control protrusions 30 are configured to be disposed on the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A. However, as needed and / or desired, the plurality of chain slippage control protrusions 30 may be configured to be disposed on only the crank arm 12 or both the crank arm 12 and the front sprocket unit 14. As needed and / or desired, the plurality of chain slippage control protrusions 30 may be configured to be disposed on both the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14.

[0101] As seen in Figures 7 and 8, a plurality of chain detachment control protrusions 30 are spaced apart from each other in a circumferential direction D3 relative to the rotation center axis A1. In this embodiment, the plurality of chain detachment control protrusions 30 are directly coupled to the first front sprocket 18. The plurality of chain detachment control protrusions 30 are directly coupled to the sprocket body 18A of the first front sprocket 18. However, as needed and / or desired, at least one of the plurality of chain detachment control protrusions 30 may be directly coupled to a cover attached to at least one of the first front sprocket 18 and the second front sprocket 20.

[0102] As shown in Figure 8, at least one chain detachment control protrusion is radially inwardly positioned from a plurality of sprocket teeth 18B. The plurality of chain detachment control protrusions 30 are at least partially radially inwardly positioned from the sprocket teeth 18B. The plurality of chain detachment control protrusions 30 are completely radially inwardly positioned from the sprocket teeth 18B. However, as needed and / or desired, the plurality of chain detachment control protrusions 30 may be partially radially inwardly positioned from the sprocket teeth 18B. As needed and / or desired, the plurality of chain detachment control protrusions 30 may be at least partially radially inwardly positioned from the sprocket teeth 18B.

[0103] As seen in Figure 9, when viewed from the axial direction D2, the plurality of chain detachment control protrusions 30 overlap with the crank arm 12. However, as required and / or desired, when viewed from the axial direction D2, at least one of the plurality of chain detachment control protrusions 30 may be configured not to overlap with the crank arm 12.

[0104] As seen in Figures 10 to 12, at least one chain detachment control protrusion 30 has a through hole 32. At least one of the plurality of chain detachment control protrusions 30 has a through hole 32. In this embodiment, each of the plurality of chain detachment control protrusions 30 has a through hole 32. However, as needed and / or desired, the through hole 32 may be omitted from at least one of the plurality of chain detachment control protrusions 30.

[0105] At least one chain detachment control protrusion 30 has a free end 33 and an attachment end 34. In this embodiment, each of the plurality of chain detachment control protrusions 30 has a free end 33 and an attachment end 34. A through hole 32 has a hole central axis A2. The hole central axis A2 extends from one of the free end 33 and the attachment end 34 to the other of the free end 33 and the attachment end 34. The attachment end 34 is configured to couple to at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14. The through hole 32 may be formed such that the through hole 32 extends to intersect a direction parallel to one of the hole central axes A2 shown in Figures 10 to 12.

[0106] In this embodiment, the attachment end 34 is configured to couple to the axially inward crank surface 12B and the axially outward sprocket surface 14A of the front sprocket unit 14. However, as needed and / or desired, the attachment end 34 may be configured to couple only to the axially inward crank surface 12B of the crank arm 12 or to both the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14.

[0107] At least one chain detachment control protrusion 30 has a chain detachment control section 36 and an attachment section 38. In this embodiment, each of the plurality of chain detachment control protrusions 30 has a chain detachment control section 36 and an attachment section 38. The attachment section 38 is adjacent to the chain detachment control section 36 in a hole axial direction D4 relative to the hole center axis A2. The attachment section 38 extends from the chain detachment control section 36 in the hole axial direction D4. The chain detachment control section 36 includes a free end 33. The attachment section 38 includes an attachment end 34. The chain detachment control section 36 can contact the drive chain 4 when the drive chain 4 detaches from the front sprocket unit 14 (e.g., the first front sprocket 18). The attachment section 38 is fixed to the front sprocket unit 14 (e.g., the first front sprocket 18).

[0108] In this embodiment, the chain detachment control section 36 and the attachment section 38 are integrally configured as a single-piece component. However, as needed and / or desired, the chain detachment control section 36 may be a component separate from the attachment section 38.

[0109] As seen in Figure 13, the front sprocket unit 14 includes an attachment hole 40. The first front sprocket 18 includes the attachment hole 40. The sprocket body 18A includes the attachment hole 40. An attachment section 38 is at least partially disposed in the attachment hole 40. The attachment section 38 extends through the attachment hole 40. A chain slippage control section 36 is disposed outside the attachment hole 40. In this embodiment, the attachment section 38 is partially disposed in the attachment hole 40. However, as needed and / or desired, the attachment section 38 may be completely disposed in the attachment hole 40.

[0110] The attachment section 38 includes a first attachment section 38A and a second attachment section 38B. The second attachment section 38B includes an attachment end 34. The first attachment section 38A is disposed in the attachment hole 40. The second attachment section 38B is disposed outside the attachment hole 40. The second attachment section 38B has an outer diameter that is larger than the outer diameter of the first attachment section 38A. For example, the second attachment section 38B is formed by forging. However, the second attachment section 38B can be formed by other methods. For example, if the attachment section 38 is coupled to the attachment hole 40 by an adhesive or by a press fit, the second attachment section 38B can be omitted from the attachment section 38.

[0111] The chain detachment control section 36 has a first maximum diameter DM21 relative to one of the hole's central axes A2. The attachment section 38 has a second maximum diameter DM22 relative to one of the hole's central axes A2. The second maximum diameter DM22 is defined by the second attachment section 38B. In this embodiment, the first maximum diameter DM21 is larger than the second maximum diameter DM22. The ratio of the first maximum diameter DM21 to the second maximum diameter DM22 is greater than or equal to 1.2. In this embodiment, the first maximum diameter DM21 is equal to 4 mm. The second maximum diameter DM22 is equal to 3 mm. The ratio of the first maximum diameter DM21 to the second maximum diameter DM22 is equal to 1.33. However, the ratio of the first maximum diameter DM21 to the second maximum diameter DM22 is not limited to the above ratio and range. The first maximum diameter DM21 is not limited to the above diameter. The second maximum diameter DM22 is not limited to the above diameter.

[0112] The chain detachment control section 36 has a first axial length L1 relative to one of the hole center axes A2. The attachment section 38 has a second axial length L2 relative to one of the hole center axes A2. The first axial length L1 is greater than the second axial length L2. The ratio of the first axial length L1 to the second axial length L2 is greater than or equal to 1.5. In this embodiment, the first axial length L1 is equal to 3.2 mm. The second axial length L2 is equal to 2 mm. The ratio of the first axial length L1 to the second axial length L2 is equal to 1.6. However, the ratio of the first axial length L1 to the second axial length L2 is not limited to the above ratio and range. The first axial length L1 is not limited to the above length. The second axial length L2 is not limited to the above length.

[0113] As shown in Figure 13, the chain detachment control section 36 has a radially outermost surface 36A relative to one of the hole's central axes A2. The free end 33 has an axially free end surface 33A relative to one of the hole's central axes A2. The chain detachment control section 36 has a chamfered portion 36B. The chamfered portion 36B is disposed between the radially outermost surface 36A and the axially free end surface 33A.

[0114] The chamfered portion 36B has a curvature. The chamfered portion 36B includes a curved surface. The curved surface includes a curved convex surface. The curved surface has a curvature. However, the shape of the chamfered portion 36B is not limited to the illustrated embodiment. Depending on need and / or desire, the chamfered portion 36B may include a surface other than a curved surface with curvature (e.g., a flat surface).

[0115] The through hole 32 has a threaded portion 32A. The threaded portion 32A is at least disposed in the chain detachment control section 36 of at least one chain detachment control protrusion 30. The threaded portion 32A includes an internal thread. In this embodiment, the threaded portion 32A is completely disposed in the chain detachment control section 36. However, as needed and / or desired, the threaded portion 32A may be partially disposed in the chain detachment control section 36.

[0116] As shown in Figure 13, the through hole 32 has a large-diameter hole 32L and a small-diameter hole 32S connected to the large-diameter hole 32L. The large-diameter hole 32L extends from the free end 33 in the axial direction D4 relative to the hole's central axis A2. The small-diameter hole 32S extends from the attachment end 34 in the axial direction D4. The large-diameter hole 32L has a large diameter DM31. The small-diameter hole 32S has a small diameter DM32. The small diameter DM32 of the small-diameter hole 32S is smaller than the large diameter DM31 of the large-diameter hole 32L. The ratio of the large diameter DM31 to the small diameter DM32 is greater than or equal to 1.3.

[0117] In this embodiment, the major diameter DM31 is equal to 2.1 mm. The minor diameter DM32 is equal to 1.6 mm. The ratio of the major diameter DM31 to the minor diameter DM32 is equal to 1.31. However, the ratio of the major diameter DM31 to the minor diameter DM32 is not limited to the above ratio and range. The major diameter DM31 is not limited to the above length. The minor diameter DM32 is not limited to the above length.

[0118] The large-diameter bore 32L and the small-diameter bore 32S are connected to each other at a connection point P1. The threaded portion 32A extends from the connection point P1 in the small-diameter bore 32S along the axial direction D4. The connection point P1 is located in the chain detachment control section 36. However, as needed and / or desired, the connection point P1 may be located in the attachment section 38.

[0119] The through hole 32 has one unthreaded portion 32B disposed in the attachment section 38. The unthreaded portion 32B is adjacent to the threaded portion 32A. The unthreaded portion 32B has one unthreaded inner diameter DM41 equal to one of the inner minor diameters DM42 of the threaded portion 32A. The unthreaded inner diameter DM41 and the inner minor diameter DM42 are equal to the minor diameter DM32 of the minor diameter hole 32S. However, as required and / or desired, at least one of the unthreaded inner diameter DM41 and the inner minor diameter DM42 may be different from the minor diameter DM32 of the minor diameter hole 32S. As required and / or desired, the unthreaded inner diameter DM41 may be different from the inner minor diameter DM42.

[0120] As seen in Figure 13, the crank assembly 10 further includes an additional chain slippage control protrusion 50. The additional chain slippage control protrusion 50 is configured to engage with the threaded portion 32A of the through-hole 32. The additional chain slippage control protrusion 50 includes a head 52 and a rod 54. The head 52 is disposed at one end of the rod 54. The rod 54 includes an additional threaded portion 54A. The additional threaded portion 54A is configured to engage with the threaded portion 32A of the through-hole 32. For example, the additional threaded portion 54A includes an external thread.

[0121] In this embodiment, the additional chain detachment control protrusion 50 is configured to be attached to the chain detachment control protrusion 30 via a threaded portion 32A and an additional threaded portion 54A. However, the additional chain detachment control protrusion 50 may be configured to be attached to the chain detachment control protrusion 30 via other structures such as an adhesive and a press fit. In these modifications, the threaded portion 32A may be omitted from the through hole 32 as needed and / or desired. The additional threaded portion 54A may be omitted from the rod 54 of the additional chain detachment control protrusion 50 as needed and / or desired.

[0122] The head 52 has a radially outermost surface 52A, an axial end face 52B, and a chamfered portion 52C. The chamfered portion 52C is disposed between the radially outermost surface 52A and the axial end face 52B. However, the chamfered portion 52C may be omitted from the head 52 as needed and / or desired.

[0123] As shown in FIG. 6, the additional chain detachment control protrusion 50 includes a tool engagement portion 55. The tool engagement portion 55 is disposed to the head 52. The tool engagement portion 55 includes a tool engagement hole 55A. In this embodiment, the tool engagement hole 55A includes a hexagonal hole. That is, the additional chain detachment control protrusion 50 includes an internal hexagonal screw. However, as needed and / or desired, the tool engagement portion 55 may be omitted from the additional chain detachment control protrusion 50. As needed and / or desired, the tool engagement portion 55 may include structures other than a hexagonal hole.

[0124] As seen in Figure 13, the head 52 has a first outer diameter DM51. The rod 54 has a second additional outer diameter DM52. For example, the second additional outer diameter DM52 is the outer major diameter of one of the additional threaded portions 54A. The first outer diameter DM51 of the head 52 is greater than the second additional outer diameter DM52 of the rod 54. The first outer diameter DM51 of the head 52 is equal to the first maximum diameter DM21 of the chain derailment control section 36. The first outer diameter DM51 of the head 52 is greater than the second maximum diameter DM22 of the attachment section 38. The second additional outer diameter DM52 of the rod 54 is less than the first maximum diameter DM21 of the chain derailment control section 36 and the second maximum diameter DM22 of the attachment section 38.

[0125] However, as needed and / or desired, the first outer diameter DM51 of the head 52 may be less than or equal to the second additional outer diameter DM52 of the rod 54. As needed and / or desired, the first outer diameter DM51 of the head 52 may differ from the second maximum diameter DM22 of the attachment section 38. As needed and / or desired, the first outer diameter DM51 of the head 52 may differ from the first maximum diameter DM21 of the chain detachment control section 36. As needed and / or desired, the first outer diameter DM51 of the head 52 may be less than or greater than the first maximum diameter DM21 of the chain detachment control section 36. As needed and / or desired, the first outer diameter DM51 of the head 52 may be less than or equal to the second maximum diameter DM22 of the attachment section 38.

[0126] The head 52 has a third axial length L3. The rod 54 has a fourth axial length L4. The third axial length L3 is defined in the axial direction D4 of the hole. The fourth axial length L4 is defined in the axial direction D4 of the hole. In this embodiment, the fourth axial length L4 is longer than the third axial length L3. The first axial length L1 of the chain detachment control section 36 is longer than both the third axial length L3 and the fourth axial length L4. The second axial length L2 of the attachment section 38 is shorter than both the third axial length L3 and the fourth axial length L4. However, as needed and / or desired, the fourth axial length L4 may be shorter than or equal to the third axial length L3. As needed and / or desired, the first axial length L1 of the chain detachment control section 36 may be shorter than or equal to at least one of the third axial length L3 and the fourth axial length L4. As needed and / or desired, the second axial length L2 of the attachment section 38 may be longer than or equal to both the third axial length L3 and the fourth axial length L4.

[0127] As seen in Figures 10 to 12, the first axial length L1 of the chain derailment control section 36 is longer than a minimum distance L5 defined in the axial direction D4 of the hole between the additional chain derailment control protrusion 50 and the crank arm 12. The sum of either the first axial length L1 or the third axial length L3 is longer than the minimum distance L5. However, as needed and / or desired, the first axial length L1 of the chain derailment control section 36 may be shorter than or equal to the minimum distance L5. As needed and / or desired, the sum of the first axial length L1 and the third axial length L3 may be shorter than or equal to the minimum distance L5.

[0128] As seen in Figures 9 and 14, the attachment section 38 has a circular cross-sectional shape. As seen in Figure 9, the second attachment section 38B has a circular cross-sectional shape. As seen in Figure 14, the first attachment section 38A has a circular cross-sectional shape. The attachment hole 40 has a circular shape. However, as seen in Figure 15, the attachment section 38 may have a non-circular cross-sectional shape as needed and / or desired. As needed and / or desired, at least one of the first attachment section 38A and the second attachment section 38B may have a shape other than a circular cross-sectional shape. The non-circular cross-sectional shape of the first attachment section 38A restricts the chain detachment control protrusion 30 from rotating relative to the front sprocket unit 14.

[0129] As shown in Figure 16, the chain detachment control section 36 has a circular cross-sectional shape. However, as needed and / or desired, the chain detachment control section 36 may have a non-circular cross-sectional shape.

[0130] As seen in Figure 17, the additional chain detachment control protrusion 50 has a circular cross-sectional shape. However, as needed and / or desired, the chain detachment control section 36 may have a non-circular cross-sectional shape. Second Embodiment

[0131] The crank assembly 210 according to a second embodiment will be described below with reference to Figures 18 to 20. Except for an electrical component and an additional chain slip control protrusion 50, the crank assembly 210 has the same structure and / or configuration as the crank assembly 10. Therefore, elements having substantially the same function as those in the first embodiment will be labeled with the same element symbols and, for the sake of brevity, will not be described in detail or illustrated here.

[0132] As shown in Figure 18, the crank assembly 210 for the human-powered vehicle 2 includes a crank arm 12 and a front sprocket unit 14. The crank assembly 210 includes a crankshaft 16.

[0133] As seen in FIG19, the crank assembly 210 for the human-powered vehicle 2 includes at least one chain derailment control protrusion 30. The at least one chain derailment control protrusion 30 comprises a plurality of chain derailment control protrusions 30. In the second embodiment, an additional chain derailment control protrusion 50 is omitted from the crank assembly 210. However, the crank assembly 210 may include an additional chain derailment control protrusion 50 as needed and / or desired.

[0134] As seen in FIG20, the crank assembly 210 further includes an electrical component 260. The electrical component 260 is disposed to the crank arm 12 at a location radially inward from a plurality of chain slip control protrusions 30. In this embodiment, the electrical component 260 includes a force sensor 262. The force sensor 262 is configured to sense forces applied to the crank arm 12. The force sensor 262 includes a strain gauge attached to the crank arm 12. However, as needed and / or desired, the force sensor 262 may include sensors other than strain gauges. As needed and / or desired, the electrical component 260 may include a component other than the force sensor 262.

[0135] The crank assembly 210 further includes a wireless communication device WC and a power supply PS. The wireless communication device WC is electrically connected to the electrical component 260. The wireless communication device WC is electrically connected to the force sensor 262. The wireless communication device WC is configured to communicate wirelessly with an additional wireless communication device. For example, the wireless communication device WC is configured to wirelessly transmit data sensed by the force sensor 262 to the additional wireless communication device.

[0136] A power supply PS is electrically connected to the electrical component 260 and the wireless communication device WC to supply power to the electrical component 260 and the wireless communication device WC. For example, the power supply PS is configured to be located in the crankshaft 16. The power supply PS includes a battery. However, as needed and / or desired, the power supply PS may be located in a location other than inside the crankshaft 16. As needed and / or desired, the power supply PS may include components other than a battery.

[0137] The crank assembly 210 further includes a cover member 264. The cover member 264 is configured to attach to the axially inward crank surface 12B of the crank arm 12 to cover the electrical assembly 260 in one assembled state of the crank assembly 210.

[0138] In this embodiment, the cover member 264 is made of a non-metallic material. The cover member 264 is made of a resin material such as synthetic resin. However, as needed and / or desired, the cover member 264 may be made of a material other than a non-metallic material.

[0139] As seen in Figure 21, the crank assembly 210 includes an additional cover member 266. The additional cover member 266 is configured to attach to the crank arm 12. For example, a wireless communication device WC is disposed in the additional cover member 266. However, as needed and / or desired, the wireless communication device WC may be disposed in a location other than inside the additional cover member 266. As needed and / or desired, the additional cover member 266 may be configured to attach to other components of the crank assembly 210.

[0140] As shown in Figure 22, the first axial length L1 of the chain detachment control section 36 is longer than a minimum distance L6 defined in the axial direction D4 of the hole between the chain detachment control protrusion 30 and the cover member 264. However, as needed and / or desired, the first axial length L1 of the chain detachment control section 36 may be shorter than or equal to the minimum distance L6.

[0141] In this embodiment, the through hole 32 has a threaded portion 32A and an unthreaded portion 32B. However, as needed and / or desired, one of the threaded portion 32A and the unthreaded portion 32B may be omitted from the through hole 32. Third Embodiment

[0142] The crank assembly 310 according to a third embodiment will be described below with reference to Figures 23 to 28. Except for the chain slip control protrusion 30, the crank assembly 310 has the same structure and / or configuration as the crank assembly 210. Therefore, elements having the same function as those in the first and second embodiments will be labeled with the same element symbols and, for the sake of brevity, will not be described in detail or illustrated here.

[0143] As shown in Figure 23, the crank assembly 310 for the human-powered vehicle 2 includes a crank arm 12 and a front sprocket unit 14. The crank assembly 310 includes a crankshaft 16.

[0144] As seen in FIG24, the crank assembly 310 for the human-powered vehicle 2 includes at least one chain slippage control member 330. In this embodiment, the crank assembly 310 includes a single chain slippage control member 330. However, as needed and / or desired, the crank assembly 310 includes a plurality of chain slippage control members 330.

[0145] As seen in Figure 25, at least one chain slippage control member 330 is configured to prevent the drive chain 4 from getting stuck in the space SP between the crank arm 12 and the front sprocket unit 14, which is arranged radially inward from the at least one chain slippage control member 330 and located in the axial direction D2.

[0146] At least one chain slippage control member 330 is configured to be disposed on at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14. The chain slippage control member 330 is configured to be disposed on the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A. However, as needed and / or desired, at least one chain slippage control member 330 may be configured to be disposed on only the axially inward crank surface 12B or both the axially inward crank surface 12B and the axially outward sprocket surface 14A.

[0147] As shown in Figure 26, at least one chain detachment control member 330 has a proximal end 332 and a free distal end 334. The free distal end 334 is arranged radially outward from the proximal end 332 relative to the rotation center axis A1. The free distal end 334 is arranged radially outward from a plurality of sprocket teeth 18B.

[0148] The proximal end 332 is attached to at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14. In this embodiment, the proximal end 332 is attached to the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A. However, as needed and / or desired, the proximal end 332 may be attached to only the axially inward crank surface 12B or both the axially inward crank surface 12B and the axially outward sprocket surface 14A.

[0149] As seen in FIG27, the crank arm 12 has a maximum circumferential crank width W1 in the circumferential direction D3 relative to the rotation center axis A1. The maximum circumferential crank width W1 is defined in the circumferential direction D3. In this embodiment, a plurality of coupling components 22 define the maximum circumferential crank width W1. However, other components of the crank arm 12 may define the maximum circumferential crank width W1 as needed and / or desired.

[0150] As seen in Figure 28, at least one chain slippage control member 330 has a maximum circumferential member width W2 in the circumferential direction D3. As seen in Figures 27 and 28, the maximum circumferential member width W2 is equal to or less than the maximum circumferential crank width W1. In this embodiment, the maximum circumferential member width W2 is less than the maximum circumferential crank width W1. However, as needed and / or desired, the maximum circumferential member width W2 may be greater than or equal to the maximum circumferential crank width W1.

[0151] As shown in Figure 28, each of the plurality of sprocket teeth 18B has a circumferential tooth width W3 defined in the circumferential direction D3 between adjacent tooth root center points TB. The sprocket teeth 18B include the tooth root center points TB and are disposed in the circumferential direction D3 between the tooth root center points TB. The maximum circumferential member width W2 is equal to or greater than the circumferential tooth width W3. The maximum circumferential member width W2 is equal to or greater than twice the circumferential tooth width W3.

[0152] In this embodiment, the maximum circumferential member width W2 is greater than the circumferential tooth width W3. The maximum circumferential member width W2 is greater than twice the circumferential tooth width W3. However, as needed and / or desired, the maximum circumferential member width W2 may be less than or equal to the circumferential tooth width W3. As needed and / or desired, the maximum circumferential member width W2 may be less than or equal to twice the circumferential tooth width W3.

[0153] At least one chain detachment control member 330 has a maximum circumferential proximal width W4 in the circumferential direction D3 at its proximal end 332. The maximum circumferential proximal width W4 is defined in the circumferential direction D3. The maximum circumferential proximal width W4 is equal to or greater than the circumferential tooth width W3. In this embodiment, the maximum circumferential proximal width W4 is greater than the circumferential tooth width W3. However, as needed and / or desired, the maximum circumferential proximal width W4 may be less than or equal to the circumferential tooth width W3.

[0154] At least one chain detachment control member 330 has a free distal end 334 having a maximum circumferential distal end width W5 in the circumferential direction D3. The maximum circumferential distal end width W5 is defined in the circumferential direction D3. The maximum circumferential distal end width W5 is equal to or greater than the circumferential tooth width W3. In this embodiment, the maximum circumferential distal end width W5 is greater than the circumferential tooth width W3. However, as needed and / or desired, the maximum circumferential distal end width W5 may be less than or equal to the circumferential tooth width W3.

[0155] As shown in FIG29, the proximal end 332 is attached at at least one of the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14 at a plurality of points 332P. In this embodiment, the proximal end 332 is attached at the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A at a plurality of points 332P. However, as needed and / or desired, the proximal end 332 may be attached at a plurality of points 332P to only the axially inward crank surface 12B or both the axially inward crank surface 12B and the axially outward sprocket surface 14A.

[0156] The chain detachment control member 330 includes a plurality of attachment members 335. The plurality of attachment members 335 define a plurality of points 332P. The plurality of attachment members 335 are spaced apart from each other in the circumferential direction D3. The plurality of attachment members 335 extend from a proximal end 332. The attachment members 335 are at least partially disposed in the attachment holes 40 of the front sprocket unit 14. In this embodiment, the attachment members 335 are partially disposed in the attachment holes 40 of the front sprocket unit 14. However, as needed and / or desired, the attachment members 335 may be completely disposed in the attachment holes 40 of the front sprocket unit 14.

[0157] The attachment member 335 includes a first attachment member 335A, a second attachment member 335B, and a hole 335C. The first attachment member 335A is disposed in the attachment hole 40. The second attachment member 335B is disposed outside the attachment hole 40. The hole 335C has a central axis A3. Point 332P is defined on the central axis A3. The first attachment member 335A has an annular shape. The second attachment member 335B has an annular shape. The second attachment member 335B has an outer diameter larger than the outer diameter of the first attachment member 335A. For example, the second attachment member 335B is formed by forging. However, the second attachment member 335B can be formed by other methods. For example, if the attachment member 335 is coupled to the attachment hole 40 by an adhesive or by a press fit, the second attachment member 335B can be omitted from the attachment member 335.

[0158] In this embodiment, the free distal end 334 and the proximal end 332 are integrally configured as a single-piece integral component. The attachment member 335 is integrally configured as a single-piece integral component with the proximal end 332. However, as needed and / or desired, the free distal end 334 may be a component separate from the proximal end 332. As needed and / or desired, at least one of the attachment members 335 may be a component separate from the proximal end 332.

[0159] In this embodiment, the total number of points 332P is 3. The total number of attachment parts 335 is 3. However, as needed and / or desired, the total number of points 332P may be greater than or equal to 2. As needed and / or desired, the total number of attachment parts 335 may be greater than or equal to 2. Modification

[0160] In the first embodiment, as seen in FIG7, at least one chain slippage control protrusion 30 is configured to be disposed on the crank arm 12 and the front sprocket unit 14. At least one chain slippage control protrusion 30 is configured to be disposed on the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A. However, as seen in FIGS. 30 and 31, at least one chain slippage control protrusion 30 may be configured to be disposed on only the crank arm 12 or both the crank arm 12 and the front sprocket unit 14, as needed and / or desired. At least one chain slippage control protrusion 30 may be configured to be disposed on both the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14, as needed and / or desired. This can also be applied to the crank assembly 210 according to the second embodiment.

[0161] In the first and second embodiments and their modifications, each of the plurality of chain detachment control protrusions 30 has the same structure as the others. However, as needed and / or desired, at least one of the plurality of chain detachment control protrusions 30 may have a structure different from that of another chain detachment control protrusion of the plurality of chain detachment control protrusions 30.

[0162] In the first embodiment and its modifications, each of the plurality of additional chain detachment control protrusions 50 has the same structure as the others. However, as needed and / or desired, at least one of the plurality of additional chain detachment control protrusions 50 may have a structure different from that of another additional chain detachment control protrusion of the plurality of additional chain detachment control protrusions 50.

[0163] In the third embodiment, as seen in FIG26, at least one chain slippage control member 330 is configured to be disposed on the front sprocket unit 14 of the crank arm 12 and the front sprocket unit 14. At least one chain slippage control member 330 is configured to be disposed on the axially outward sprocket surface 14A of the axially inward crank surface 12B and the axially outward sprocket surface 14A. However, as seen in FIGS.32 and 33, at least one chain slippage control member 330 may be configured to be disposed on only the crank arm 12 or both the crank arm 12 and the front sprocket unit 14, as needed and / or desired. At least one chain slippage control member 330 may be configured to be disposed on both the axially inward crank surface 12B of the crank arm 12 or the axially inward crank surface 12B of the crank arm 12 and the axially outward sprocket surface 14A of the front sprocket unit 14, as needed and / or desired.

[0164] In the modified embodiment illustrated in Figure 33, each of the plurality of chain detachment control members 330 has a different structure from the others. However, as needed and / or desired, at least one of the plurality of chain detachment control members 330 may have a structure identical to that of another chain detachment control member of the plurality of chain detachment control members 330.

[0165] The first to third embodiments and their modifications may be combined with each other as needed and / or desired. For example, the crank assembly 10 may include at least one chain slippage control protrusion 30 and at least one chain slippage control member 50.

[0166] In this application, as used herein, the term "comprising" and its derivatives are intended to be open-ended terms, specifically referring to the presence of the stated features, elements, components, groups, integers and / or steps, but not excluding the presence of other unstated features, elements, components, groups, integers and / or steps. This concept also applies to terms with similar meanings, such as the terms "having," "comprising," and their derivatives.

[0167] The terms “component”, “section”, “part”, “part”, “element”, “body” and “structure” used in the singular form may have a dual meaning of a single component or a plurality of components.

[0168] The ordinal numbers such as "first" and "second" used in this application are merely identifiers and do not have any other meaning, such as a specific order or the like. Furthermore, for example, the term "first element" does not imply the existence of "second element," and the term "second element" does not imply the existence of "first element."

[0169] As used herein, the term "pair" may include configurations in which the element pairs have the same shape or structure as each other, or configurations in which the element pairs have different shapes or structures from each other.

[0170] The terms “a”, “one or more” and “at least one” are used interchangeably in this document.

[0171] As used in this invention, the phrase “…at least one of” means “one or more” of a selection. For example, as used in this invention, if the number of selections is 2, the phrase “…at least one of” means “only one single selection” or “all two selections”. For another example, as used in this invention, if the number of selections is equal to or greater than three, the phrase “…at least one of” means “only one single selection” or “any combination of equal to or greater than two selections”. For example, the phrase “at least one of A and B” covers (1) only A, (2) only B, and (3) both A and B. The phrase “at least one of A, B, and C” covers (1) only A, (2) only B, (3) only C, (4) both A and B, (5) both B and C, (6) both A and C, and (7) all A, B, and C. In other words, in this invention, the phrase "at least one of A and B" does not mean "at least one of A and at least one of B".

[0172] Finally, as used herein, degree terms such as “substantially,” “about,” and “approximately” mean a reasonable deviation amount of a modified term that does not significantly alter the final result. All numerical values ​​described in this application may be interpreted as including terms such as “substantially,” “about,” and “approximately.”

[0173] Obviously, many modifications and variations of the present invention can be made in light of the foregoing teachings. Therefore, it should be understood that the present invention can be practiced in ways other than those specifically described herein, within the scope of the appended claims. [Simplified Explanation of the Diagram]

[0043] The present invention and its many accompanying advantages will be readily understood and better appreciated by taking into account the following detailed description with reference to the accompanying drawings.

[0044] FIG1 is a perspective view of a crank assembly according to a first embodiment.

[0045] Figure 2 is a side view of the crank assembly shown in Figure 1, wherein one crank arm is omitted.

[0046] Figure 3 is a cross-sectional view of the crank assembly taken along line III-III of Figure 2.

[0047] Figure 4 is another side view of the crank assembly shown in Figure 1.

[0048] Figure 5 is a cross-sectional view of the crank assembly taken along line VV in Figure 2.

[0049] Figure 6 is a perspective view of a portion of the crank assembly shown in Figure 1.

[0050] Figure 7 is a top view of a portion of the crank assembly shown in Figure 1.

[0051] Figure 8 is a cross-sectional view of the crank assembly taken along line VIII-VIII of Figure 7.

[0052] Figure 9 is a partial side view of the crank assembly shown in Figure 1.

[0053] Figure 10 is a partial cross-sectional view of the crank assembly taken along line XX in Figure 9.

[0054] Figure 11 is a partial cross-sectional view of the crank assembly taken along line XI-XI of Figure 9.

[0055] Figure 12 is a partial cross-sectional view of the crank assembly taken along line XII-XII in Figure 9.

[0056] Figure 13 is an enlarged cross-sectional view of one of the crank assemblies shown in Figure 12.

[0057] Figure 14 is a partial cross-sectional view of the crank assembly taken along line XIV-XIV in Figure 7.

[0058] Figure 15 is a partial cross-sectional view of a crank assembly according to a modified scheme.

[0059] Figure 16 is a partial cross-sectional view of the crank assembly taken along line XVI-XVI of Figure 7.

[0060] Figure 17 is a partial cross-sectional view of the crank assembly taken along line XVII-XVII of Figure 7.

[0061] FIG18 is a perspective view of a crank assembly according to a second embodiment.

[0062] Figure 19 is a partial perspective view of the crank assembly shown in Figure 18.

[0063] Figure 20 is a partial cross-sectional view of the crank assembly taken along line XX-XX in Figure 18.

[0064] Figure 21 is another perspective view of one of the crank assemblies shown in Figure 18.

[0065] Figure 22 is an enlarged cross-sectional view of one of the crank assemblies shown in Figure 20.

[0066] Figure 23 is a perspective view of a crank assembly according to a third embodiment.

[0067] Figure 24 is a partial perspective view of the crank assembly shown in Figure 23.

[0068] Figure 25 is a partial cross-sectional view of the crank assembly taken along line XXV-XXV in Figure 23.

[0069] Figure 26 is an enlarged cross-sectional view of one of the crank assemblies shown in Figure 25.

[0070] Figure 27 is a side view of the crank assembly shown in Figure 23.

[0071] Figure 28 is a partial side view of the crank assembly shown in Figure 23.

[0072] Figure 29 is a partial cross-sectional view of the crank assembly taken along line XXIX-XXIX in Figure 28.

[0073] Figure 30 is a partial top view of a crank assembly according to one of the modified schemes.

[0074] Figure 31 is a partial top view of a crank assembly according to another modified version.

[0075] Figure 32 is a partial rear view of a crank assembly according to one of the other modifications.

[0076] Figure 33 is a partial rear view of a crank assembly according to one of the other modifications.

Claims

1. A crank assembly for a human-powered vehicle, the crank assembly comprising: A crank arm having an axially outward crank surface and an axially inward crank surface disposed on a reverse side of the axially outward crank surface in an axial direction relative to a rotational center axis of the crank assembly, the axially inward crank surface being configured to face an axial center plane of the human-powered vehicle in an axial direction during an installation state in which the crank assembly is mounted to the human-powered vehicle; a front sprocket unit having an axially outward sprocket surface and an axially inward sprocket surface disposed on a reverse side of the axially outward sprocket surface in an axial direction, the axially inward sprocket surface being configured to face the axial center plane of the human-powered vehicle in an axial direction during the installation state, the front sprocket unit comprising: A sprocket body; and a plurality of sprocket teeth, which extend radially outward from the sprocket body in a radial direction relative to one of the rotational central axes; and a plurality of sprocket disengagement control protrusions configured to prevent a drive chain from falling into a space between the crank arm and the front sprocket unit located radially inward from the plurality of chain disengagement control protrusions in the axial direction, the plurality of chain disengagement control protrusions being configured to be disposed on at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit, the plurality of chain disengagement control protrusions being spaced apart from each other in a circumferential direction relative to one of the rotational central axes.

2. The crank assembly of claim 1, further comprising: An electrical assembly is disposed at one of the locations radially inward from the plurality of chain detachment control protrusions to the crank arm.

3. The crank assembly of claim 2, wherein the electrical component includes a force sensor.

4. The crank assembly of claim 2, further comprising: A cover member configured to attach to the axially inward crank surface of the crank arm to cover the electrical component in one assembled state of the crank assembly.

5. The crank assembly of claim 4, wherein the cover component is made of a non-metallic material.

6. The crank assembly of claim 1, wherein the plurality of chain slip control protrusions are at least partially disposed radially inward from the sprocket teeth.

7. The crank assembly of claim 1, wherein, when viewed from the axial direction, the plurality of chain detachment control protrusions overlap the crank arm.

8. The crank assembly of claim 1, wherein the total number of one of the plurality of chain detachment control protrusions is equal to or greater than 3.

9. A crank assembly for a human-powered vehicle, the crank assembly comprising: A crank arm having an axially outward crank surface and an axially inward crank surface disposed on a reverse side of the axially outward crank surface in an axial direction relative to a rotational center axis of the crank assembly, the axially inward crank surface being configured to face an axial center plane of the human-powered vehicle in the axial direction during a mounting state in which the crank assembly is mounted to the human-powered vehicle, the crank arm having a maximum circumferential crank width in a circumferential direction relative to the rotational center axis; a front sprocket unit having an axially outward sprocket surface and an axially inward sprocket surface disposed on a reverse side of the axially outward sprocket surface in the axial direction, the axially inward sprocket surface being configured to face the axial center plane of the human-powered vehicle in the axial direction during the mounting state, the front sprocket unit comprising: A sprocket body; and a plurality of sprocket teeth, which extend radially outward from the sprocket body in a radial direction relative to one of the rotational central axes; and at least one chain slippage control member configured to prevent a drive chain from falling into a space between the crank arm and the front sprocket unit located radially inward from the at least one chain slippage control member and in the axial direction, the at least one chain slippage control member being configured to be disposed to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit, the at least one chain slippage control member having a proximal end and a free distal end, the proximal end being attached to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit, the free distal end being arranged radially outward from the proximal end relative to the rotational central axis, the at least one chain slippage control member having a maximum circumferential member width in the circumferential direction, the maximum circumferential member width being equal to or less than the maximum circumferential crank width.

10. The crank assembly of claim 9, wherein each of the plurality of sprocket teeth has a circumferential tooth width defined between the center points of adjacent tooth roots in the circumferential direction, and the width of the largest circumferential member is equal to or greater than the circumferential tooth width.

11. The crank assembly of claim 10, wherein the width of the maximum circumferential member is equal to or greater than twice the width of the circumferential tooth.

12. The crank assembly of claim 10, wherein the proximal end of the at least one chain slip control member has a maximum circumferential proximal width in the circumferential direction, and the maximum circumferential proximal width is equal to or greater than the circumferential tooth width.

13. The crank assembly of claim 10, wherein the free distal end of the at least one chain slip control member has a maximum circumferential distal width in the circumferential direction, and the maximum circumferential distal width is equal to or greater than the circumferential tooth width.

14. The crank assembly of claim 9, wherein the free distal end is arranged radially outward from the plurality of sprocket teeth.

15. The crank assembly of claim 9, further comprising: An electrical component is disposed to the crank arm at a location radially inward from the at least one chain detachment control member.

16. The crank assembly of claim 15, wherein the electrical component includes a force sensor.

17. The crank assembly of claim 15, further comprising: A cover member configured to attach to the axially inward crank surface of the crank arm to cover the electrical component in one assembled state of the crank assembly.

18. The crank assembly of claim 17, wherein the cover member is made of a non-metallic material.

19. A crank assembly for a human-powered vehicle, the crank assembly comprising: A crank arm having an axially outward crank surface and an axially inward crank surface disposed on a reverse side of the axially outward crank surface in an axial direction relative to a rotational center axis of the crank assembly, the axially inward crank surface being configured to face an axial center plane of the human-powered vehicle in the axial direction during a mounting state in which the crank assembly is mounted to the human-powered vehicle, the crank arm having a maximum circumferential crank width in a circumferential direction relative to the rotational center axis; a front sprocket unit having an axially outward sprocket surface and an axially inward sprocket surface disposed on a reverse side of the axially outward sprocket surface in the axial direction, the axially inward sprocket surface being configured to face the axial center plane of the human-powered vehicle in the axial direction during the mounting state, the front sprocket unit comprising: A sprocket body; and a plurality of sprocket teeth, which extend radially outward from the sprocket body in a radial direction relative to one of the rotation center axes; and at least one chain slippage control member configured to prevent a drive chain from falling into a space disposed radially inward from the at least one chain slippage control member and located in the axial direction between the crank arm and the front sprocket unit, the at least one chain slippage control member being configured to be disposed to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit, the at least one chain slippage control member having a proximal end and a free distal end, the proximal end being attached at a plurality of points to at least one of the axially inward crank surface of the crank arm and the axially outward sprocket surface of the front sprocket unit, the at least one chain slippage control member having a maximum circumferential member width in the circumferential direction, the maximum circumferential member width being equal to or less than the maximum circumferential crank width.

20. The crank assembly of claim 19, wherein each of the plurality of sprocket teeth has a circumferential tooth width defined between the center points of adjacent tooth roots in the circumferential direction; and the width of the largest circumferential member is equal to or greater than the circumferential tooth width.

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