Bicycle crank arm

Abstract

The present disclosure relates to a bicycle crank arm. The bicycle crank can include a first lug, a second lug, and a transition region. The first lug is for connecting to a spindle. The second lug is for connecting to a pedal; the transition region interconnects the first lug and the second lug and is formed from a fiber-reinforced thermoplastic material, the fiber-reinforced thermoplastic material including a fiber component and a thermoplastic component.

Description

Technical Field

[0001] This disclosure relates to a bicycle crank arm, and more specifically, to a bicycle crank arm made of fiber-reinforced thermoplastic material and / or having a reinforced structure. Background Technology

[0002] Traditional bicycle composite cranks or crank arms are made of thermoset composite prepregs, which require pre-layout or stacking and thermoforming processes. Thermoset composites cannot be reshaped after thermoforming, making products from these materials non-recyclable and non-reusable. These products may be disposed of by burying or burning, and are harmful to the environment. Furthermore, the pre-treatment of thermoset composite prepregs before thermoforming requires significant manpower and time, resulting in low production efficiency. The yield of these products is also susceptible to inconsistent human operation, leading to high scrap rates and increasing the cost of this production method. Summary of the Invention

[0003] According to this disclosure, a bicycle crank includes a first lug, a second lug, and a transition region. The first lug is used to connect to the spindle. The second lug is used to connect to the pedals. The transition region interconnects the first lug and the second lug and is formed of a fiber-reinforced thermoplastic material, which includes a fiber component and a thermoplastic component. Attached Figure Description

[0004] Other features and advantages of this disclosure will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings, wherein:

[0005] Figure 1 A bicycle crank according to this disclosure is shown for use in a bicycle;

[0006] Figure 2 It is a 3D diagram of a bicycle crank.

[0007] Figure 3 This is another three-dimensional view of a bicycle crank;

[0008] Figure 4 It is a three-dimensional view of the first metal lug of a bicycle crank;

[0009] Figure 5 It is a three-dimensional view of the second metal lug of a bicycle crank;

[0010] Figure 6 This is a side view of a bicycle crank.

[0011] Figure 7 It is along Figure 6 A cross-sectional view of the bicycle crank taken by line VII-VII;

[0012] Figure 8 It is along Figure 6 Another sectional view of the bicycle crank taken by line VIII-VIII;

[0013] Figure 9 This is a side view of an embodiment of a bicycle crank;

[0014] Figure 10 It is along Figure 9 The line XX was intercepted Figure 9 A cross-sectional view of an embodiment;

[0015] Figure 11 It is along Figure 9 The line XI-XI intercepted Figure 9 Another cross-sectional view of the embodiment;

[0016] Figure 12 This is a side view of another embodiment of a bicycle crank;

[0017] Figure 13 It is along Figure 12 The line XIII-XIII intercepted Figure 12 A cross-sectional view of an embodiment;

[0018] Figure 14 It is along Figure 13 The line XIV-XIV intercepted Figure 12 Another cross-sectional view of the embodiment;

[0019] Figure 15 It is along Figure 13 The line XV-XIV intercepted Figure 12 Another cross-sectional view of an embodiment;

[0020] Figure 16 yes Figure 6 A side view of a bicycle crank, showing the distribution of continuous fiber components in the fiber-reinforced thermoplastic material that forms the bicycle crank;

[0021] Figure 17 This is a sectional perspective view, which shows along... Figure 16 The cross-section of the bicycle crank intercepted by line XVII-XVII;

[0022] Figure 18 yes Figure 9 A side view of an embodiment, showing the distribution of continuous fiber components in the fiber-reinforced thermoplastic material forming this embodiment;

[0023] Figure 19 yes Figure 12A side view of an embodiment, showing the distribution of continuous fiber components in the fiber-reinforced thermoplastic material forming this embodiment;

[0024] Figure 20(a) is a side view of another embodiment of a bicycle crank;

[0025] Figure 20(b) is a cross-sectional view of the embodiment in Figure 20(a) taken along line XXb-XXb of Figure 20(a);

[0026] Figure 20(c) is another cross-sectional view of the embodiment in Figure 20(a) taken along line XXc-XXc of Figure 20(a);

[0027] Figure 21(a) is a side view of another embodiment of a bicycle crank;

[0028] Figure 21(b) is a cross-sectional view of the embodiment in Figure 21(a) taken along line XXIb-XXIb of Figure 21(a);

[0029] Figure 21(c) is another cross-sectional view of the embodiment in Figure 21(a) taken along line XXIc-XXIc of Figure 21(a);

[0030] Figure 22(a) is a side view of another embodiment of a bicycle crank;

[0031] Figure 22(b) is a cross-sectional view of the embodiment in Figure 22(a) taken along line XXIIb-XXIIb of Figure 22(a);

[0032] Figure 22(c) is another cross-sectional view of the embodiment in Figure 22(a) taken along line XXIIc-XXIIc of Figure 22(a);

[0033] Figure 23(a) is a side view of another embodiment of a bicycle crank;

[0034] Figure 23(b) is a cross-sectional view of the embodiment in Figure 23(a) taken along line XXIIIb-XXIIIb of Figure 23(a);

[0035] Figure 23(c) is another cross-sectional view of the embodiment in Figure 23(a) taken along line XXIIIc-XXIIIc of Figure 23(a);

[0036] Figure 24(a) is a side view of another embodiment of a bicycle crank;

[0037] Figure 24(b) is a cross-sectional view of the embodiment in Figure 24(a) taken along line XXIVb-XXIVb of Figure 24(a);

[0038] Figure 25(a) is a side view of another embodiment of a bicycle crank;

[0039] Figure 25(b) is a cross-sectional view of the embodiment in Figure 25(a) taken along line XXVb-XXVb of Figure 25(a);

[0040] Figure 26 This is a partially exploded perspective view showing another embodiment of a bicycle crank;

[0041] Figure 27 yes Figure 26 A perspective view of an embodiment;

[0042] Figure 28 yes Figure 26 A cross-sectional view of an embodiment;

[0043] Figure 29 This is a partially exploded perspective view illustrating another embodiment of a bicycle crank; and

[0044] Figure 30 This is a partially exploded perspective view showing another embodiment of a bicycle crank. Detailed Implementation

[0045] Before describing this disclosure in more detail, it should be noted that reference numerals or the end portions of reference numerals have been repeated between the figures where deemed appropriate, in order to indicate corresponding or similar elements, which may optionally have similar characteristics.

[0046] Figure 1 A bicycle 10 is shown, in which at least the bicycle crank 100 according to this disclosure is used. The bicycle 10 includes a main frame 101, a front wheel 102, a rear wheel 103, and a drivetrain 104. The front wheel 102 and the rear wheel 103 are rotatably connected to the main frame 101. The bicycle 10 further includes a braking system comprising a front brake 105 and a rear brake 106 for braking the front wheel 102 and the rear wheel 103, respectively. The drivetrain 104 includes a chain 107, a spindle 7 rotatably mounted to the main frame 101, a front sprocket assembly 108 coaxially mounted to the spindle 7, and a rear sprocket assembly 109 coaxially mounted to the rear wheel 103. Each of the front sprocket assembly 108 and the rear sprocket assembly 109 includes at least one chainring. The direction of arrow "A" indicates the forward direction of movement of the bicycle 10.

[0047] exist Figure 1In the illustration, bicycle 10 is shown as a fully suspended mountain bike with flat handlebars. However, the bicycle crank 100 according to this disclosure is applicable to various bicycles with single-speed and multi-speed drivetrains, the multi-speed drivetrain having a derailleur system. The derailleur system may include a front derailleur unit and / or a rear derailleur unit. The braking system and the derailleur system may be mechanically controlled or non-mechanically controlled.

[0048] Further reference Figure 2 and Figure 3 The bicycle crank 100 includes a pedal attachment portion configured to attach to a pedal. The pedal attachment portion includes features that facilitate pedal attachment. For example, the pedal attachment portion may include an internally threaded portion configured to receive a corresponding externally threaded portion of the pedal. Figure 2 and Figure 3 As shown, the pedal attachment portion includes a lug, such as a first lug 1 or a pedal attachment lug. The first lug 1 includes features for attachment to the pedal, as described herein. The first lug 1 is formed of a material capable of bearing the loads borne by attaching and removing the pedal and operating the bicycle crank 100. In embodiments, the first lug 1 is formed of a material different from that of the bicycle crank 100. In embodiments, the first lug 1 may be formed of a metallic material. For example, the first lug 1 may be formed of an aluminum-based or steel-based material.

[0049] The bicycle crank 100 also includes a spindle attachment portion. The spindle attachment portion includes features that facilitate attachment of the spindle. For example, the spindle attachment portion may include a section comprising features configured to receive corresponding features of the spindle to ensure proper attachment and torque transmission between the spindle and the bicycle crank 100. Figure 2 and Figure 3 As shown, the spindle attachment portion includes a lug, such as a second lug 2 or a spindle attachment lug. The second lug 2 includes features for attachment to the spindle, as described herein. The second lug 2 is formed of a material capable of bearing the loads borne by attaching and removing the spindle and operating the bicycle crank 100. In embodiments, the second lug 2 is formed of a material different from that of the bicycle crank 100. In embodiments, the second lug 2 may be formed of a metallic material. For example, the second lug 2 may be formed of an aluminum-based or steel-based material.

[0050] The first lug 1 and the second lug 2 can be formed of the same or different materials. In this embodiment, the first lug 1 and the second lug 2 are both formed of the same metallic material, such as aluminum.

[0051] In an alternative implementation, the spindle may be formed together with the bicycle crank 100 or otherwise permanently attached to the bicycle crank 100.

[0052] The bicycle crank 100 also includes a transition region 3 that connects the pedal attachment portion and the spindle attachment portion. For example... Figure 2 and Figure 3 As shown, transition region 3 interconnects the first lug 1 and the second lug 2. Transition region 3 is formed of a material different from that of the first lug 1 and / or the second lug 2. As described herein, transition region 3 is made of a fiber-reinforced thermoplastic material (i.e., a thermoplastic composite material) comprising a fiber component and a thermoplastic component. The fiber component can be any fiber. For example, the fiber component can be selected from the group consisting of: carbon fiber, glass fiber, natural fiber, polyaramid fiber, metal fiber, and combinations thereof. The thermoplastic component can be any thermoplastic component. For example, the thermoplastic component can be selected from the group consisting of: polypropylene (PP), polyamide (PA), polycarbonate (PC), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherimide (PEI), and combinations thereof.

[0053] In one embodiment, the thermoplastic composite material can be reformed after being heated above its heat distortion temperature. Additionally, in another embodiment, the thermoplastic composite material can be formed by injection molding, printing (e.g., 3D printing), and / or thermoforming.

[0054] Further reference Figure 4 and Figure 5 The first lug 1 has an internal spline 11 that rotatably engages with the spindle 7. In one embodiment, the first lug 1 may further have an anti-rotation structure 14 formed on its outer periphery. In one embodiment, the first lug 1 may further have an external spline 12 that rotatably engages with the chainring 9 of the front sprocket assembly 108. In one embodiment, the first lug 1 may further have a plurality of threaded holes 13 that allow a plurality of bolts (not shown) to engage therewith, thereby securing the chainring 9 to the first lug 1. The second lug 2 has a threaded hole 21 for connecting the pedal 8 to the second lug 2. In this way, the bicycle crank 100 can be used to transmit torque from the pedal 8 to the chainring 9 and the spindle 7.

[0055] Reference Figures 6 to 8The transition region 3 includes a base segment 30. The base segment 30 has a base surface 301 that extends along the length of the transition region 3. In one embodiment, the transition region 3 further includes a first reinforcing structure 31 that extends along the length of the transition region 3. In one embodiment, the transition region 3 further includes a second reinforcing structure 32 that extends along the length of the transition region 3 and is spaced apart from the first reinforcing structure 31. In one embodiment, at least one of the first reinforcing structure 31 and the second reinforcing structure 32 extends from the base surface 301 of the base segment 30. In one embodiment, at least one of the first reinforcing structure 31 and the second reinforcing structure 32 is a peripheral reinforcing structure extending from the periphery of the base surface 301 of the base segment 30.

[0056] Reference Figure 16 and Figure 17 In this embodiment, at least one of the first reinforcing structure 31 and the second reinforcing structure 32 comprises a continuous fiber (F) formed from a fiber component in a fiber-reinforced thermoplastic material. In one embodiment, each of the first reinforcing structure 31 and the second reinforcing structure 32 is configured as a wall segment. In one embodiment, at least one of the first reinforcing structure 31 and the second reinforcing structure 32 may comprise discontinuous fibers.

[0057] In some embodiments, the transition region 3 may further include an intermediate reinforcement structure disposed between the first reinforcement structure 31 and the second reinforcement structure 32.

[0058] Reference Figure 9 and Figure 11 In one embodiment, the transition region 3 includes at least one base-extended reinforcement segment 34 that extends from the base surface 301. In one embodiment, the base-extended reinforcement segment 34 connects the first reinforcement structure 31 and the second reinforcement structure 32. The base-extended reinforcement segment 34 serves as an intermediate reinforcement structure.

[0059] Reference Figure 18 The base extension reinforcement section 34 comprises continuous fibers (F) formed from the fiber component in the fiber-reinforced thermoplastic material. In one embodiment, the base extension reinforcement section 34 may be configured as ribs. In one embodiment, the base extension reinforcement section 34 may include discontinuous fibers.

[0060] In one embodiment, the transition region includes multiple intermediate reinforcement structures. For example, transition region 3 includes multiple base-extended reinforcement segments 34, each extending from the base surface 301. In one embodiment, at least one of the base-extended reinforcement segments 34 may be connected between the first reinforcement structure 31 and the second reinforcement structure 32. In this embodiment, the base-extended reinforcement segments 34 cooperatively form an X-shaped structure. Other structural shapes may also be formed. In one embodiment, the base-extended reinforcement segments 34 are formed of continuous fibers (F).

[0061] Reference Figures 12 to 15 In one embodiment, the transition region includes an intermediate reinforcement structure configured as a spanning reinforcement segment 33 spaced apart from the base surface 301.

[0062] In one embodiment, the spanning reinforcement section 33 is connected to at least one of the distal ends of the first reinforcement structure 31 and the second reinforcement structure 32.

[0063] In one embodiment, the straddle reinforcement segment 33 has at least one cavity 331 formed therethrough. The cavity 331 serves to reduce the weight of the straddle reinforcement segment 33 while maintaining sufficient structural strength of the straddle reinforcement segment 33.

[0064] In the implementation method, refer to Figure 19 The cross-reinforcement section 33 comprises continuous fibers (F) formed from the fiber component in the fiber-reinforced thermoplastic material. In one embodiment, the cross-reinforcement section 33 may be configured as a wall section. In one embodiment, the cross-reinforcement section 33 may include discontinuous fibers.

[0065] Referring to FIG20(a), in an embodiment, the transition region 3 includes a plurality of basic extended reinforcement segments 34 extending from the basic segment 30, disposed between the first reinforcement structure 31 and the second reinforcement structure 32, and cooperatively forming a plurality of X-shaped structures arranged along the extension direction of the transition region 3. Referring particularly to FIGS20(b) and 20(c), the height of each basic extended reinforcement segment 34 in the lateral direction (T) may differ from that of the other basic extended reinforcement segments, or may vary along the extension portion of the transition region 3, such that the depth (in the lateral direction (T)) of the space defined between the basic extended reinforcement segments 34 varies along the extension direction of the transition region 3.

[0066] Reference Figures 21(a) to 21(c)In an embodiment, the width of each basic extended reinforcement segment 34 may be different from the width of other basic extended reinforcement segments, which extend from the basic segment 30 and are disposed between the first reinforcement structure 31 and the second reinforcement structure 32.

[0067] Reference Figures 22(a) to 22(c) In an embodiment, the cross angle (A) of each X-shaped structure formed by the basic extended reinforcement section 34 may be different from the cross angle of the other X-shaped structures, the basic extended reinforcement section extending from the basic section 30 and disposed between the first reinforcement structure 31 and the second reinforcement structure 32.

[0068] Reference Figures 23(a) to 23(c) In one embodiment, the transition region 3 includes a plurality of basic extension reinforcement segments 34, each extending from a basic segment 30 and disposed between the first reinforcement structure 31 and the second reinforcement structure 32, and each basic extension reinforcement segment 34 is arc-shaped. In one embodiment, each basic extension reinforcement segment 34 connects between the first reinforcement structure 31 and the second reinforcement structure 32. The basic extension reinforcement segments 34 cooperatively form at least one annular structure. Other structural shapes may also be formed.

[0069] Reference Figures 24(a) to 25(b) In one embodiment, the transition region 3 includes an intermediate reinforcement structure configured as an intermediate body segment 35. The intermediate body segment 35 extends from the base surface 301 of the base segment 30 and connects between the first reinforcement structure 31 and the second reinforcement structure 32. In one embodiment, the intermediate body segment 35 defines a plurality of intermediate cavities 351 therein. The intermediate cavities 351 are used to reduce the weight of the intermediate body segment 35 while maintaining sufficient structural strength. In one embodiment, the intermediate cavities 351 may extend through the intermediate body segment 35.

[0070] Referring particularly to Figures 24(a) and 24(b), in one embodiment, the central cavity 351 is constructed as a hexagonal hole and arranged such that the central body section 35 has a honeycomb structure.

[0071] Referring particularly to Figures 25(a) and 25(b), in one embodiment, the central cavity 351 may be rectangular, circular, elliptical, or other shapes.

[0072] Reference Figures 26 to 28In one embodiment, the bicycle crank 100 further includes a shell 4 formed of a material different from the thermoplastic component in the fiber-reinforced thermoplastic material. The shell 4 may cover at least a portion of the transition region 3 to protect that portion. In one embodiment, the transition region 3 has a mounting recess 39 to which the shell 4 is mounted. In another embodiment, the material forming the shell 4 has a harderness than the thermoplastic component in the fiber-reinforced thermoplastic material. In yet another embodiment, the material forming the shell 4 is metal. The shell 4 can be mounted to the transition region 3 by insert molding, hot pressing, resin transfer molding, or bonding.

[0073] Reference Figure 29 In one embodiment, the bicycle crank 100 may include a plurality of housings 4. In one embodiment, a transition region 3 is formed with a plurality of mounting recesses 39, to which the housings 4 are respectively mounted.

[0074] Reference Figure 30 In this embodiment, the shell 4 can be used as a decorative accessory. In this embodiment, the transition region 3 is formed with a mounting recess 39 for mounting the shell 4.

[0075] In summary, since thermoplastic composites can be re-deformed after being heated to their heat distortion temperature, the bicycle crank according to this disclosure is recyclable and reusable. Furthermore, since thermoplastic composites can be molded by injection, printing, and thermoforming, the yield of the bicycle crank according to this disclosure is improved compared to that of conventional thermoset composite bicycle cranks.

[0076] Finally, based on load tests (data not shown) conducted on the bicycle crank of this disclosure, the applicant has found that the bicycle crank made of thermoplastic composite material (i.e. fiber-reinforced thermoplastic material) still has sufficient structural strength, as well as recyclability and reusability.

[0077] In the above description, numerous specific details have been set forth for illustrative purposes to provide a more comprehensive understanding of the embodiments. However, it will be apparent to those skilled in the art that one or more other embodiments may be implemented without some of these specific details. It should also be understood that references to “one embodiment,” “implementation,” or embodiments with ordinal numbers in this specification mean that specific features, structures, or unique features may be included in embodiments of this disclosure. It should also be understood that in the specification, various features are sometimes grouped together in the description of a single embodiment, figure, or figure to streamline the disclosure and aid in understanding the various inventive points; and in embodiments of this disclosure, one or more features or specific details from one embodiment may be implemented together with one or more features or specific details from another embodiment, if appropriate.

[0078] While this disclosure has been described in conjunction with embodiments that are considered exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included in the spirit and scope of the widest interpretation, thereby encompassing all such modifications and equivalent arrangements.

Claims

1. A bicycle crank, the bicycle crank comprising: A first lug (1) is adapted to connect a spindle; A second lug (2) is adapted to connect a pedal; A transition region (3) interconnects the first lug (1) and the second lug (2), the transition region (3) being formed of a fiber-reinforced thermoplastic material comprising fiber components and thermoplastic components. The transition region (3) includes: The base section (30) has a base surface (301) extending along the length of the transition region (3); A first reinforcing structure (31) extends along the length of the transition region (3) and from the base surface (301); A second reinforcing structure (32) extends along the length of the transition region (3), extends from the base surface (301), and is spaced apart from the first reinforcing structure (31); and An intermediate reinforcement structure disposed between the first reinforcement structure (31) and the second reinforcement structure (32); and At least one shell (4) is formed of a material different from the thermoplastic component in the fiber-reinforced thermoplastic material and covers a portion of the transition region (3), wherein the material forming the shell (4) has a harder hardness than the thermoplastic component in the fiber-reinforced thermoplastic material.

2. The bicycle crank according to claim 1, wherein, At least one of the first reinforcement structure (31) and the second reinforcement structure (32) is a peripheral reinforcement structure extending from the periphery of the base segment (30).

3. The bicycle crank according to claim 1, wherein, The first reinforcing structure (31) comprises continuous fibers (F) formed from the fiber components in the fiber-reinforced thermoplastic material.

4. The bicycle crank according to claim 1, wherein, The intermediate reinforcement structure is configured as a spanning reinforcement section (33) spaced apart from the base surface (301).

5. The bicycle crank according to claim 4, wherein, The cross-reinforcement section (33) has at least one cavity (331) formed through the cross-reinforcement section.

6. The bicycle crank according to claim 4, wherein, The cross-reinforced section (33) comprises a continuous fiber (F) formed from the fiber component in the fiber-reinforced thermoplastic material.

7. The bicycle crank according to claim 1, wherein, The intermediate reinforcement structure is configured as a base extension reinforcement section (34) that extends from the base surface (301) and connects the first reinforcement structure (31) and the second reinforcement structure (32).

8. The bicycle crank according to claim 7, wherein, The transition region (3) includes a plurality of the base extension reinforcement segments (34), each base extension reinforcement segment extending from the base surface (301) and connecting between the first reinforcement structure (31) and the second reinforcement structure (32), the base extension reinforcement segments (34) cooperatively forming an X-shaped structure.

9. The bicycle crank according to claim 7, wherein, The basic extended reinforcement section (34) includes continuous fibers (F) formed from the fiber components in the fiber-reinforced thermoplastic material.

10. The bicycle crank according to claim 7, wherein, The transition region (3) includes a plurality of the base extension reinforcement segments (34), each base extension reinforcement segment extending from the base surface (301) and connecting between the first reinforcement structure (31) and the second reinforcement structure (32), the base extension reinforcement segments (34) cooperatively forming a plurality of X-shaped structures arranged along the extension direction of the transition region (3).

11. The bicycle crank according to claim 7, wherein, The transition region (3) includes a plurality of the base extension reinforcement segments (34), each base extension reinforcement segment extending from the base surface (301) and connecting between the first reinforcement structure (31) and the second reinforcement structure (32), the base extension reinforcement segments (34) cooperatively forming a ring structure.

12. The bicycle crank according to claim 1, wherein, The intermediate reinforcement structure is configured as an intermediate main body section (35) that extends from the base surface (301) and connects between the first reinforcement structure (31) and the second reinforcement structure (32), and the intermediate main body section (35) defines a plurality of intermediate cavities (351) in the intermediate main body section.

13. The bicycle crank according to claim 12, wherein, The intermediate cavity (351) is constructed as a hexagonal hole and arranged in such a way that the intermediate main body section (35) has a honeycomb structure.

14. The bicycle crank according to claim 1, wherein, The material forming the shell (4) is metal.

15. The bicycle crank according to claim 1, wherein, The fiber component is selected from the group consisting of: carbon fiber, glass fiber, natural fiber, polyaramid fiber, metal fiber and combinations thereof, and the thermoplastic component is selected from the group consisting of: polypropylene (PP), polyamide (PA), polycarbonate (PC), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherimide (PEI) and combinations thereof.

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