TWI733444B - Crank and sprocket assembly for a bicycle - Google Patents

Abstract

A crank and sprocket assembly for a bicycle is provided, including: a first crank body, including a first flange portion having a plurality of first teeth protruding outwardly, the plurality of first teeth defining a plurality of tooth grooves therebetween, at least one of the plurality of tooth grooves which is wider than the rest of the plurality of tooth grooves being defined as at least one restricting groove; a connecting member, having a through hole, an inner edge of the through hole having a plurality of second teeth protruding therefrom, at least one of the plurality of second teeth which is wider than the rest of the plurality of second teeth being defined as at least one restricting tooth, a width of the at least one restricting tooth being smaller than a width of the at least one restricting groove and larger than a width of each of the rest of the plurality of tooth grooves, the plurality of second teeth being engaged within the plurality of tooth grooves; wherein the at least one restricting tooth is engaged within the least one restricting groove; and a sprocket, being oval and assembled with the connecting member, an outer edge of the sprocket having a plurality of tooth portions disposed thereon.

Description

Bicycle crank and chainring structure

The present invention is related to the structure of the crank and chainring of a bicycle.

Generally speaking, the bicycle chainring is a perfect circle, but the force that the user can exert when riding on the pedal will vary depending on the pedaling position. For example, it is most difficult for the user to apply force when the pedal is vertical, and it is used when the pedal is horizontal. It’s the easiest to apply force, which causes waste of force and laborious vertical position. Therefore, there is a prior art that uses an elliptical gear wheel to adjust the force, such as the one disclosed in the patent TW M579614, with the difference between the long and short axis The length of the chainring can reduce the waste of power and effort, and make the riding easier.

However, because of this, the relative angle between the chainring and the crank will greatly affect the riding effect. If the relative angle between the chainring and the crank is deviated, the effect of the elliptical chainring may be lost, and it may even be more laborious to use. However, it is difficult to quickly and correctly assemble the chainring and crank.

On the other hand, when the bicycle wants to move, the rider stepped on the left and right cranks, and through the connection of the celestial axis to receive the power from the left and right feet to drive the gears to rotate to pull the chain and drive the rim to rotate, such as Taiwan Patent M589155 The crank connection structure disclosed by I676572 and M585232 belongs to this category.

It is understandable that there are many sizes of cranks, shafts, and bottom brackets. Although there are basic size ranges, all manufacturers and various bicycle models still have their own special specifications and sizes. Therefore, when you want to use it When the style is not specified, there will often be assembly gaps. Moreover, even if the specified style of components is used, the assembly gap and the instability of the fit of the components will still be caused due to processing errors.

The main purpose of the present invention is to provide a bicycle crank and chainring structure, through the specially designed meshing structure, the combination and positioning of the crank and the chainring are easier, and can be fine-tuned to a certain extent as required.

To achieve the above objective, the present invention provides a bicycle crank and chainring structure, which includes a first crank body, a connecting member, a chainring, and a locking member.

The first crank body has a first insertion hole and a first flange portion, the first flange portion surrounds the first insertion hole, and one end of the first flange portion radially protrudes farther from its free end. A plurality of first convex teeth are formed, and the first convex teeth are arranged at intervals around the first insertion hole to form a plurality of tooth grooves. At least one of the tooth grooves has a circumferential width greater than that of the other tooth grooves. Defined as at least one limiting groove; the connecting piece is penetrated with a perforation, the inner edge of the perforation protrudes radially to form a plurality of second convex teeth, and the circumferential width of at least one second convex tooth is larger than that of the other second convex teeth The circumferential width of the tooth is defined as at least one limiting tooth. The circumferential width of the at least one limiting tooth is smaller than the circumferential width of the at least one limiting groove but larger than the circumferential width of the remaining tooth grooves. Two convex teeth are respectively embedded in the tooth grooves, wherein the at least one limiting tooth is embedded in the at least one limiting groove, and the at least one limiting tooth is selectively located in the periphery of the at least one limiting groove One of at least two different positions upward; the toothed disk is for installation on the connecting member and has an elliptical contour; the circumference of the toothed disk is formed with a plurality of tooth portions arranged at intervals to the outer edge; the locking member can It is detachably locked to the free end of the first flange portion to prevent the connecting piece from falling out of the free end of the first flange portion.

The following examples are only used to illustrate the possible implementation aspects of the present invention, but they are not intended to limit the scope of protection of the present invention.

Please refer to FIGS. 1 to 11, which show a preferred embodiment of the present invention. The bicycle crank and chainring structure of the present invention includes a first crank body 10, a connecting member 20, a chainring 30, and a locking member 60 .

The first crank body 10 has a first insertion hole 11 and a first flange portion 12, the first flange portion 12 surrounds the first insertion hole 11, and the first flange portion 12 is far away from its free One end of the end protrudes radially to form a plurality of first convex teeth 131. The first convex teeth 131 are arranged at intervals around the first insertion hole 11 to form a plurality of tooth grooves 132. At least one of the tooth grooves 132 has a circumferential width It is defined as at least one limiting groove 133 which is larger than the circumferential width of the remaining tooth grooves 132; the connecting member 20 is provided with a through hole 21, and the inner edge of the through hole 21 radially protrudes to form a plurality of second convex teeth 22, at least The circumferential width of one second convex tooth 22 is greater than the circumferential width of each of the remaining second convex teeth 22 and is defined as at least one limiting tooth 23, and the circumferential width of the at least one limiting tooth 23 is smaller than the at least one limit The circumferential width of the positioning groove 133 is larger than the circumferential width of the remaining tooth grooves 132. The second convex teeth 22 are respectively embedded in the tooth grooves 132, and the at least one limiting tooth 23 is embedded in the tooth grooves 132. In at least one limiting groove 133, the at least one limiting tooth 23 is selectively located at one of at least two different positions in the circumferential direction in the at least one limiting groove 133; The connecting member 20 has an elliptical contour. A plurality of tooth portions 31 are formed at intervals on the outer periphery of the toothed disk 30; the locking member 60 is detachably locked to the free end of the first flange portion 12, This prevents the connecting member 20 from falling out of the free end of the first flange portion 12.

Preferably, the outer edge of the first flange portion 12 is provided with a first threaded portion 121, the locking member 60 is ring-shaped and the inner edge is provided with a second threaded portion 61, and the second threaded portion 61 is provided with the first threaded portion 61. The threaded portion 121 is screwed, so that the locking member 60 is screwed to the first flange portion 12.

In the main embodiment of the present invention, the at least one constraining groove 133 can accommodate a constraining tooth 23 and two second convex teeth 22 other than the constraining tooth 23, that is, the at least one constraining groove There are exactly three different positions for the fit between 133 and the at least one limiting tooth 23: the at least one limiting tooth 23 is located at the leftmost, center, or rightmost of the at least one limiting groove 133; on the other hand, the at least one limiting tooth 23 The position of the bit tooth 23 preferably corresponds to a long side of the elliptical contour of the toothed disk 30.

In more detail, in this embodiment, the number of the at least one limiting groove 133 and the at least one limiting tooth 23 is two respectively, and the two limiting teeth 23 are located at opposite ends of the perforation 21 in the radial direction. The two limiting grooves 133 are located at opposite ends of the second flange portion 13 in the radial direction; the number of the second convex teeth 22 other than the limiting teeth 23 is 32, and the number of the second convex teeth 22 other than the limiting grooves 133 is 32. The number of the tooth grooves 132 is 28; the connecting member 20 is generally X-shaped and has four connecting ends 24, the perforation 21 is formed in the center of the connecting member 20, and the connecting ends 24 are for connecting the toothed disk 30.

Therefore, since the limiting tooth 23 can only be accommodated in the limiting slot 133, the user does not need to guess whether the relative assembly angle of the connecting member 20 and the first crank body 10 is correct, and can quickly complete the correct assembly. During slight angle adjustment, the position of the limit tooth 23 in the limit groove 133 can also be changed to achieve the effect of fine adjustment of the angle. Especially for the specially designed elliptical gear plate, the assembly position is suitable for riding. Force is particularly important, and such an assembly structure allows users to quickly complete assembly or adjustment.

In addition, the bicycle crank and chainring structure provided by the present invention further includes two screw members 40, 80, a shaft member 50, a tension member 90, and a second crank body 70. The second crank body 70 has a second crank body 70. The insertion hole 71 and a third flange portion 72 surround the second insertion hole 71. The two screws 40 and 80 are respectively rotatably positioned on the first crank body 10 and The second crank body 70, parts of the two screws 40, 80 are respectively accommodated in the first insertion hole 11 and the second insertion hole 71, and the shaft 50 is provided for passing through a bottom bracket 100 The opposite ends respectively extend into the first insertion hole 11 and the second insertion hole 71 to be screwed to the two screw members 40, 80, so that the shaft member 40, 80 is connected to the first crank body 10 and the The second crank body 70 is in a co-rotational relationship. In detail, during the installation process, the screws 40 and 80 are used to pull the shaft 50 so that the shaft 50 can reliably extend into the first The insertion hole 11 or the second insertion hole 71 to a certain depth, in order to achieve the purpose of stable combination; the tightening member 90 is generally ring-shaped and movably positioned on the third flange portion 72 for being provided along an axial direction The five-way tube set 100 is pressed to eliminate the gap between the second crank body 70 and the five-way tube set 100. More specifically, the pressing member 90 can tightly abut the five-way tube set The bearing of 100 is used to stabilize the bearing. When the rider steps on the pedal to drive the second crank body 70 to rotate, it is expected to have excellent rotation stability, and after long-term use, it is less prone to skew and structural deformation. .

In detail, the outer edge of the third flange portion 72 is provided with a third threaded portion 721, the inner edge of the pressing member 90 is provided with a fourth threaded portion 91, and the fourth threaded portion 91 is provided with the third threaded portion 721. Screwing makes the tightening member 90 screwed to the third flange portion 72, and the user only needs to rotate the tightening member 90 to adjust the position, which is quite convenient and fast, and the thread structure has the characteristic of continuous position Therefore, the pressing member 90 can be precisely adjusted to various positions to reliably resist the five-way tube group 100 of various shapes and sizes; preferably, the pressing member 90 is generally C-shaped so that its opposite ends are spaced apart Is arranged to form a notch 92, an adjusting member 93 is screwed to the opposite ends of the pressing member 90, and the adjusting member 93 is used to adjust the distance between the opposite ends of the pressing member 90, so that the pressing member 90 can There is enough radial margin to be assembled on the third flange portion 72 of different radial sizes; the pressing member 90 is formed with a top edge 94 at one end in the axial direction. The inner diameter of the top edge 94 is smaller than that of the pressing member 90 of the inner diameter of the other part, the top edge 94 is used to cover the free end of the third flange portion 72 and to press against the five-way pipe group 100.

Regarding the shaft member 50, the shaft member includes two insertion sections 51 and a penetration section 52, the penetration section 52 is connected between the two insertion sections 51, and the radial dimension of each insertion section 51 is smaller than the penetration section 51 The radial dimension of the segment 52, and each insertion segment 51 is tapered away from the penetration segment 52, at least one of the insertion segments 51 and the penetration segment 52 are connected to each other to form a step structure 53 for The second insertion hole 71 is inserted, and the penetration section 52 is used to pass through the five-way tube group 100. As a result, when the insertion section 51 extends into the second insertion hole 71 to a predetermined position, the third The flange portion 72 can block the step structure 53, so that the insertion section 51 cannot go further, so that the user clearly knows that the insertion section 51 has actually reached the tightly coupled position; wherein, the shaft of the shaft 50 In the direction, the step structure 53 is in an interference configuration corresponding to the third flange portion 72. Preferably, the step structure 53 includes a first step 531 and a second step 532. The second step The portion 532 is farther away from the axis of the shaft 50 than the first step portion 531; wherein, when the insertion section 51 extends into the second insertion hole 71 to a predetermined depth, the first step portion 531 is used to abut against The third flange portion 72 and the second step portion 532 are used for abutting against the pressing member 90.

Preferably, the outer wall of each insertion section 51 of the shaft member 50 is formed with a plurality of ribs 511 arranged at intervals along the circumferential direction, and at least one of the ribs 511 of each insertion section 51 has a circumferential width greater than that of the other The circumferential width of the convex rib 511 is defined as at least one limiting rib 512. The inner walls of the first insertion hole 11 and the second insertion hole 71 are respectively formed with a plurality of grooves 111, 711 arranged at intervals in the circumferential direction, at least The circumferential width of one of the grooves 111, 711 is greater than the circumferential width of the other grooves 111, 711 and is defined as at least one limiting groove 112,712, and the at least one limiting rib 512 is provided for engaging with the at least one limiting groove 112,712. , The convex ribs 511 other than the at least one limiting rib 512 and the concave grooves 111,711 other than the at least one limiting groove 112,712 are engaged with each other, so that the shaft member 50 cannot be opposed to the first crank body 10 or the The second crank body 70 rotates.

More preferably, the outer ring surface of the pressing member 90 is formed with a plurality of protrusions 95 along the circumferential direction, and the protrusions 65 are arranged at intervals so that the outer ring surface of the pressing member 90 is gear-shaped, so as to facilitate the hand or Other tools are combined with the drive to easily apply force; in addition, in the axial direction of the shaft member 50, the ratio of the thickness of the pressing member 90 to the length of the insertion section 51 is between 0.3 and 0.6.

In actual use, since the insertion section is tapered toward the direction away from the penetration section, the insertion section is easier to align and insert into the second insertion hole, and as the user rotates the screw to pull the insertion section deeper When the second insertion hole is used, the shaft can be more and more closely combined with the second crank body, and gradually form a tight fit. This is the first stage of combination; the user still has to turn the screw until the shaft After the first step portion of the component abuts against the third flange portion, the process is the second stage of combination. At this time, the shaft component and the second crank body are truly assembled and locked in a stable manner.

10: The first crank body 11: The first socket 111: Groove 112: Limit groove 12: The first flange 121: The first thread 13: Second flange 131: First convex tooth 132: cogging 133: Limit slot 20: connecting piece 21: Piercing 22: second convex tooth 23: limit tooth 24: connecting end 30: chainring 31: Teeth 40: Screw 50: Shaft 51: Insert paragraph 511: Convex Rib 512: limit rib 52: Wearing section 53: Step structure 531: First Stage 532: Second Stage 60: lock firmware 61: The second thread part 70: The second crank body 71: second socket 711: Groove 712: limit groove 72: Third flange 721: third threaded part 80: Screw 90: Compression 91: The fourth thread 92: gap 93: adjustment parts 94: top edge 95: bump 100: Five-way pipe group

Figure 1 is a partial front view of the present invention. Figure 2 is a partial perspective view of the present invention. Figure 3 is an exploded perspective view of the present invention. Figure 4 is a partial schematic diagram of the present invention. Fig. 4A is a partial enlarged view of Fig. 4. Figure 5 is a partial schematic diagram of the present invention. Fig. 5A is a partial enlarged view of Fig. 5. Figure 6 is a side view of the present invention. Figure 7 is a partially exploded cross-sectional view of the present invention. Figure 8 is a partial cross-sectional view of the present invention. Fig. 9 is a perspective view of the pressing member of the present invention. Fig. 10 is a front view of the pressing member of the present invention. Figure 11 is a cross-sectional view of the pressing member of the present invention.

10: Crank body

12: The first flange

13: Second flange

20: connecting piece

30: chainring

40: Screw

Claims (10)

A bicycle crank and chainring structure includes: a first crank body with a first insertion hole and a first flange part, the first flange part surrounds the first insertion hole, and the first flange One end of the part farther from its free end protrudes radially to form a plurality of first convex teeth, the first convex teeth are arranged at intervals around the first insertion hole to form a plurality of tooth grooves, at least one of the tooth grooves has a circumferential width It is defined as at least one limiting groove which is larger than the circumferential width of the other tooth grooves; a connecting piece is penetrated with a perforation, and the inner edge of the perforation radially protrudes to form a plurality of second convex teeth, at least one of the second convex The circumferential width of the tooth is greater than the circumferential width of the remaining second convex teeth and is defined as at least one limiting tooth, the circumferential width of the at least one limiting tooth is smaller than the circumferential width of the at least one limiting groove but larger than the rest The circumferential width of each tooth groove, the second convex teeth are respectively embedded in the tooth grooves, wherein the at least one limiting tooth is embedded in the at least one limiting groove, and the at least one limiting tooth is selected Sexually located at one of at least two different positions in the circumferential direction in the at least one limiting groove; a toothed disk for installation on the connecting member and having an elliptical contour, the circumference of the toothed disk is to the outer edge Formed with a plurality of tooth portions arranged at intervals; and a locking member detachably locked on the free end of the first flange portion to prevent the connecting piece from falling out of the free end of the first flange portion; wherein the One end of the first flange portion farther from its free end protrudes radially outward to form a second flange portion, and the first convex teeth are formed on the second flange portion. According to the bicycle crank and chainring structure of claim 1, wherein the at least one limiting groove can exactly accommodate a limiting tooth and two second convex teeth other than the limiting tooth. The bicycle crank and chainring structure according to claim 1, wherein the position of the at least one limiting tooth corresponds to a long side of the elliptical contour of the chainring. The bicycle crank and chainring structure according to claim 1, wherein the outer edge of the first flange portion is provided with a first threaded portion, the locking member is ring-shaped and the inner edge is provided with a second threaded portion, the second thread The part is used for screwing with the first threaded part, so that the locking member is screwed with the first flange part. The bicycle crank and chainring structure as described in claim 1, further comprising two screw members, a shaft member, a pressing member, and a second crank body, the second crank body having a second insertion hole and a third protrusion The edge portion, the third flange portion surrounds the second insertion hole, the two screws are respectively rotatably positioned on the first crank body and the second crank body, and parts of the two screws are respectively accommodated in The first insertion hole and the second insertion hole, the shaft member for passing through the opposite ends of a five-way tube group respectively extends into the first insertion hole and the second insertion hole to be screwed with the two screws The shaft is screwed together to make the shaft and the first crank body and the second crank body have the same rotational relationship. The tightening member is generally ring-shaped and movably positioned on the third flange portion for traversing a The five-way pipe group is pressed axially. The bicycle crank and chainring structure according to claim 5, wherein the outer edge of the third flange portion is provided with a third threaded portion, the inner edge of the tightening member is provided with a fourth threaded portion, and the fourth threaded portion is provided with The third threaded portion is screwed to make the pressing member screwed to the third flange portion, the pressing member is generally C-shaped so that its opposite ends are spaced apart to form a gap, and an adjusting member is screwed to The opposite ends of the pressing element are used for adjusting the distance between the opposite ends of the pressing element. The bicycle crank and chainring structure according to claim 6, wherein one end of the pressing member in the axial direction is further formed with a top edge, the inner diameter of the top edge is smaller than the inner diameter of other parts of the pressing member, and the top edge is used for The free end of the third flange is covered and used to oppose the five-way pipe group. The bicycle crank and chainring structure according to claim 5, wherein the shaft includes two insertion sections and a penetration section, the penetration section is connected between the two insertion sections, and the radial dimension of each insertion section Is smaller than the radial dimension of the piercing section, and each of the insertion sections is tapered toward the direction away from the piercing section, at least one of the insertion sections and the piercing section are connected to each other to form a step structure for inserting the Second plug The through section is for passing through the five-way pipe group; wherein, in the axial direction of the shaft member, the step structure corresponds to the third flange portion in an interference configuration. The bicycle crank and chainring structure according to claim 7, wherein the step structure includes a first step and a second step, and the second step is farther from the axis of the shaft than the first step ; Wherein, when the insertion section extends into the second insertion hole to a predetermined depth, the first step portion is used to abut against the third flange portion, and the second step portion is used to abut against the pressing Pieces. The bicycle crank and chainring structure according to claim 6, wherein the shaft includes two insertion sections and a penetration section, the penetration section is connected between the two insertion sections, and the radial dimension of each insertion section Is smaller than the radial dimension of the piercing section, and each of the insertion sections is tapered toward the direction away from the piercing section, at least one of the insertion sections and the piercing section are connected to each other to form a step structure for inserting the The second insertion hole, the penetration section is for passing through the five-way pipe group; wherein, in the axial direction of the shaft member, the step structure corresponds to the third flange portion in an interference configuration; the step portion The structure includes a first step portion and a second step portion, the second step portion is farther from the shaft center of the shaft member than the first step portion; wherein, when the insertion section extends into the second insertion hole to a predetermined depth , The first step portion is used to abut against the third flange portion, and the second step portion is used to abut against the pressing member; the at least one limiting groove can accommodate a limiting tooth and two The second convex tooth other than the limiting tooth; the position of the at least one limiting tooth corresponds to a long side of the elliptical contour of the gear plate; the number of the at least one limiting groove and the at least one limiting tooth are respectively Two, and the two limiting teeth are located at opposite ends in the radial direction of the perforation, and the two limiting grooves are located at opposite ends in the radial direction of the second flange part; the second protrusions other than the limiting teeth The number of teeth is 32, and the number of tooth grooves other than the limiting grooves is 28; the connecting piece is generally X-shaped and has four connecting ends. The perforation is formed in the center of the connecting piece, and the connecting ends are provided for Connect the gear plate; the outer wall of each insertion section of the shaft member is formed with a plurality of ribs arranged at intervals in the circumferential direction, and the circumferential width of at least one of the ribs of each insertion section is greater than the circumference of the other ribs Depends on the width It means at least one limiting rib. The inner walls of the first insertion hole and the second insertion hole are respectively formed with a plurality of grooves arranged at intervals in the circumferential direction, and at least one of the grooves has a circumferential width greater than that of the other grooves. The circumferential width of the groove is defined as at least one limiting groove, the at least one limiting rib is for fitting with the at least one limiting groove, and the protruding ribs other than the at least one limiting rib are for the at least one limiting rib. The recessed grooves other than a limiting groove are fitted with each other so that the shaft cannot rotate relative to the first crank body or the second crank body; the outer ring surface of the pressing member is formed with a plurality of protrusions along the circumferential direction, The protrusions are arranged at intervals so that the outer ring surface of the pressing member is gear-shaped; in the axial direction of the shaft member, the ratio of the thickness of the pressing member to the length of the insertion section is between 0.3 and 0.6 The outer edge of the first flange portion is provided with a first threaded portion, the locking member is ring-shaped and the inner edge is provided with a second threaded portion, the second threaded portion for screwing with the first threaded portion, so that the The locking member is screwed on the first flange part.

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