Transmission sprocket for bicycles

Abstract

A transmission sprocket for bicycles, comprising: a first disc body made of a first non-metallic material and having a plurality of teeth on the outer circumference; a second disc body made of a second non-metallic material, which covers one side of the first disc body and together with the first disc body forms an annular interior space; and a support layer consisting of a third non-metallic material located in the interior, wherein the third non-metallic material is different from the first non-metallic material and the second non-metallic material.

Description

Field of the invention

[0001] The present invention relates to a sprocket and, more particularly, to a transmission sprocket for bicycles. State of the art

[0002] When cycling, the weight of the bicycle represents an additional burden for the rider. Therefore, reducing bicycle weight has become one of the main directions in bicycle development.

[0003] To reduce the weight of a bicycle, in addition to optimizing the frame structure, the materials used for the body can also be changed. However, due to different material properties, the original body structure may no longer be sufficiently strong after a change in the body material. Accordingly, the body design must be adapted to the properties of the new material. Object of the invention

[0004] The present invention provides a transmission sprocket for bicycles having the advantages of light weight and high structural strength.

[0005] To achieve the above-mentioned advantages, an embodiment of the present invention provides a transmission sprocket for bicycles comprising a first disc body, a second disc body and a support layer, wherein the first disc body is made of a first non-metallic material and has a plurality of teeth on the outer circumference, the second disc body is made of a second non-metallic material and covers one side of the first disc body and forms an annular inner space together with the first disc body, and the support layer is made of a third non-metallic material and is located in the inner space, the third non-metallic material being different from the first non-metallic material and the second non-metallic material.

[0006] In one embodiment, a plurality of ribs are provided on the side of the first disk body or the second disk body facing the interior space, wherein these ribs extend along the radial direction of the transmission sprocket and divide the interior space into a plurality of separation chambers.

[0007] In one embodiment, the first disc body has a first disc surface and a first annular wall protruding from the first disc surface.

[0008] In one embodiment, the second disk body has a second disk surface and a second annular wall protruding from the second disk surface, wherein the first annular wall and the second annular wall abut one another.

[0009] In one embodiment, the first disc body has a central axis, wherein the first disc surface, the second disc surface of the second disc body and the first annular wall or the second annular wall together form an interior space, wherein the distance between the first disc surface and the second disc surface gradually decreases along a radial direction from the first annular wall towards the direction remote from the central axis.

[0010] In one embodiment, the first non-metallic material and the second non-metallic material are fiber composite materials and the third non-metallic material is a foam.

[0011] In one embodiment, the first non-metallic material and the second non-metallic material are made of the same material.

[0012] In one embodiment, the first disc body and the second disc body are formed in one piece.

[0013] Based on the above description, the transmission sprocket for bicycles according to an embodiment of the present invention has the advantage that the first disc body and the second disc body are lightweight due to the use of non-metallic materials. By disposing the support layer made of a non-metallic material in the internal space enclosed by the first disc body and the second disc body, the first disc body and the second disc body can be supported by the support layer. In this way, the structural strength of the transmission sprocket for bicycles can be increased while maintaining the advantage of light weight.

[0014] Further features, objects and advantages of the present invention will be explained in detail with reference to the following embodiment in conjunction with the accompanying drawings. Brief description of the drawings Fig. 1 shows a schematic exploded view of an embodiment of the transmission sprocket for bicycles according to the invention; Fig. Figure 2 shows a schematic perspective view of the transmission sprocket for bicycles according to the invention according to Fig. 1; Fig. 3 shows a schematic sectional view along the section line AA according to Fig. 1; Fig. 4 shows a schematic sectional view according to Fig. 3 without the base layer; Fig. 5 shows a schematic rear view of the second disc body according to Fig. 1; Fig. 6 shows a flowchart of the manufacturing method of an embodiment of the transmission sprocket for bicycles according to the invention. Detailed description of the embodiment

[0015] Hereinafter, the orientation words such as "top," "bottom," etc. used in the description of the embodiment according to the present invention are based on the orientation or positional relationship shown in the figures and are used only to simplify the description of the present invention. These orientation words do not indicate or imply that the referenced elements must have a particular orientation or be constructed in a particular orientation. Furthermore, the terms "first" and "second" mentioned in this description or in the claims are used only to name elements or to distinguish different embodiments or ranges and do not serve to limit the upper or lower limit of the number of elements.

[0016] Fig. 1 shows a schematic exploded view of an embodiment of the transmission sprocket for bicycles according to the invention; Fig. Figure 2 shows a schematic perspective view of the transmission sprocket for bicycles according to the invention according to Fig. 1; Fig. 3 shows a schematic sectional view along the section line AA according to Fig. 1; Fig. 4 shows a schematic sectional view according to Fig. 3 without the base layer; Fig. 5 shows a schematic rear view of the second disc body according to Fig. 1.

[0017] It is based on the Fig. 1 to 3. The transmission sprocket for bicycles 100 according to an embodiment of the present invention includes a first disc body 1, a second disc body 2, and a support layer 3. The first disc body 1 is made of a non-metallic material. The non-metallic material may be a carbon fiber composite material, a glass fiber composite material, a fiber-reinforced plastic, or other high-strength polymer materials. The first disc body 1 has a plurality of teeth 1a on its outer circumference. The second disc body 2 is made of a non-metallic material. The non-metallic material may be a carbon fiber composite material, a glass fiber composite material, a fiber-reinforced plastic, or other high-strength polymer materials.The first disc body 1 and the second disc body 2 can be made of the same material, depending on the required strength and weight of the final product. The second disc body 2 covers one side of the first disc body 1 and, together with it, forms an annular interior space S, wherein the center of the second disc body 2 and the center of the interior space S lie on the central axis A of the first disc body 1. As shown in . Fig. 3, the support layer 3 consists of a third non-metallic material and is located in the interior space S. The third non-metallic material differs from the first non-metallic material and second non-metallic material, which will be described in detail later.

[0018] In the present embodiment, the center axis of the transmission sprocket for bicycles 100 and the center axis of the second disc body 2 coincide with the center axis A.

[0019] In the present embodiment, the transmission sprocket for bicycles 100 further comprises, for example, a spider 4 which is designed, for example, to be connected to a bicycle crank (not shown) and a sprocket 5 (see Fig. 2). The spider 4 is, for example, cross-shaped, but the present invention is not subject to any restrictions in this regard. The center of the spider 4 lies on the central axis A and is provided with a connecting hole 41 suitable for connection to a bicycle crank. The material of the spider 4 is not subject to any particular restrictions and can be selected as needed.

[0020] As in the Fig. 1 to 3, in the present embodiment, the first disc body 1 can be made in one piece from a carbon fiber composite material. When the transmission sprocket for bicycles 100 is combined with a frame (not shown), the first disc body 1 is located, for example, on a side of the transmission sprocket for bicycles 100 facing away from the frame. The first disc body 1 is, for example, annular and has a first disc wall 11, a first annular wall 12, and a plurality of fastening sections 13.

[0021] Continuing with the above, in the present exemplary embodiment, the first disc wall 11 has a first disc surface 110 on a side facing the second disc body 2 (i.e., the side of the first disc wall 11 facing the frame during assembly). The normal direction of the first disc surface 110 runs, for example, parallel to the central axis A. In the present exemplary embodiment, the first disc wall 11 has a plurality of recesses 111. The first disc surface 110 represents, for example, the bottom surface of the recesses 111, but is not limited thereto. The teeth 1a of the first disc body 1 are located, for example, on the outer circumference of the first disc wall 11.

[0022] In the present embodiment, the first annular wall 12 is located on the inner circumference of the first disc wall 11. The first annular wall 12 protrudes, for example, from the surface of the first disc surface 110 along the extension direction parallel to the central axis A of the transmission sprocket for bicycles 100 in the direction of the second disc body 2. The outer wall of the first annular wall 12 (the wall surface of the first annular wall 12 facing away from the central axis A) is perpendicular to the first disc surface 110, for example, but is not limited thereto.

[0023] Continuing with the above, the attachment portions 13 are, for example, a plurality of blocks protruding from the inner wall of the first annular wall 12 (the wall surface of the first annular wall 12 facing the central axis A) toward the central axis A of the bicycle transmission sprocket 100. The number of attachment portions 13 corresponds, for example, to the number of plates of the spider 4, and the shape of the attachment portions 13 corresponds, for example, to the shape of the plates of the spider 4.

[0024] When assembling the first disc body 1 and the spider 4, the tabs of the spider 4 are connected to the fastening sections 13 of the first disc body 1. The type of connection between the fastening sections 13 and the spider 4 is not subject to any restrictions and can, for example, be achieved by screw connections or adhesive bonding, as required. The shape of the first disc body 1 can be designed as required. In an embodiment not shown, the first disc body 1 and the spider 4 can be formed as a single piece.

[0025] It is based on the Fig. 1 to 3 and 5. Specifically, the second disk body 2 can be manufactured in one piece from a carbon fiber composite material. In the present exemplary embodiment, for example, the outer diameter and the inner diameter of the second disk body 2 are smaller than the outer diameter and the inner diameter, respectively, of the first disk body 1. The second disk body 2 is, for example, annular and has an annular second disk wall 21 and a second annular wall 22.

[0026] It is based on the Fig. 1 to 5. In the present exemplary embodiment, the second disc wall 21 has a second disc surface 210 on the side facing the first disc body 1. The second disc wall 21 extends, for example, obliquely from the side of the second annular wall 22 located near the central axis A in the direction remote from the central axis A and gradually approaches the first disc body 1. The dimensions of the second disc wall 21 are selected, for example, such that they completely cover the recesses 111 of the first disc body 1 when the first disc body 1 and the second disc body 2 are assembled.

[0027] The shape of the second disc wall 21 is not particularly limited. In the present embodiment, for example, the second disc wall 21 has a stepped structure on the surface opposite the second disc surface 210 and includes a plurality of first ring portions 212 and a plurality of second ring portions 213. For example, there are three first ring portions 212, and one of the first ring portions 212 is located on the outer periphery of the second disc body 2. Each first ring portion 212 extends obliquely from the side near the central axis A toward the side farther from the central axis A, gradually approaching the side of the second disc body 2 near the first disc body 1. For example, there are two second ring portions 213.Each second ring section 213 is connected to two adjacent first ring sections 212 and is located therebetween and does not run parallel to the first ring sections 212.

[0028] The second annular wall 22 extends, for example, along the direction parallel to the central axis A of the transmission sprocket for bicycles 100 from the inner edge of the second disc surface 210 toward the side on which the first disc body 1 is located, and is designed to be brought into contact with the first annular wall 12 when the second disc body 2 and the first disc body 1 are assembled.

[0029] It is based on the Fig. 3 and Fig. 4. During assembly, the first annular wall 12 and the second annular wall 22 are in contact with each other, and the portion of the first disk wall 11 near the outer periphery and the outer periphery of the second disk wall 21 are also in contact with each other. In the present embodiment, the inner wall of the second annular wall 22 (the wall surface of the second annular wall 22 near the central axis A) abuts the outer wall of the first annular wall 12, so that the interior space S is formed by the first disk surface 110, the second disk surface 210, and the second annular wall 22, but can be configured as needed. Fig. 3 or Fig. 4 it can be seen that the distance between the first disc surface 110 and the second disc surface 210 gradually decreases along a radial direction from the first annular wall 12 towards the direction away from the central axis A.

[0030] It is based on the Fig. 3 and Fig. 4. Since the first disc surface 110 is located on the underside of the recesses 111, the volume of the interior space S can be increased by the arrangement of the recesses 111, and the volume and weight of the first disc body 1 can be reduced.

[0031] The exact manner in which the first disc body 1 and the second disc body 2 are bonded together can be designed as needed, for example, by heating so that the contact points between the first disc body 1 and the second disc body 2 melt and are bonded together. Alternatively, an adhesive can be used between the first disc body 1 and the second disc body 2.

[0032] Since there are no special restrictions regarding the size ratios between the second disk body 2 and the first disk body 1, the interior space S can be formed in an embodiment not shown by the first disk surface 110, the second disk surface 210 and the first disk wall 12 according to the relative size ratio between the first annular wall 12 and the second annular wall 22.

[0033] It is based on the Fig. 1 to 5. In the present embodiment, ribs 112 and ribs 211 are provided on the side of the first disc body 1 and the second disc body 2 facing the interior space S, respectively. These ribs (the ribs 112 and the ribs 211) extend along the radial direction of the bicycle transmission sprocket 100 and divide the interior space S into a plurality of separation chambers. The separation chambers are not continuously connected to one another, for example, but are not limited thereto.

[0034] As in Fig. 1, the ribs 112 of the first disc body 1 are provided, for example, between two recesses 111 of the first disc wall 11 and serve as partition walls between two adjacent recesses 111. As shown in Fig. 5, the ribs 211 of the second disc body 2 are provided, for example, between the second disc surface 210 and the second annular wall and are located, for example, opposite the ribs 112 of the first disc body 1. The ribs 112 and the ribs 211 can be connected to each other during assembly of the first disc body 1 and the second disc body 2 to divide the interior space S into a plurality of chambers that are not continuously connected to each other. However, it should be understood that the exact shape of the ribs 112 and the ribs 211 can be adjusted as needed.

[0035] There are no particular restrictions on the arrangement of the ribs 112 and the ribs 211. In the present embodiment, for example, the transmission sprocket for bicycles 100 comprises a plurality of step-up members 6. The ribs 112 and the ribs 211 extend along a radial direction from the central axis A to the corresponding step-up members 6, with gaps 211a provided on the outer periphery of the second disk body 2 and serving to pass through the corresponding step-up members 6, but the present invention is not subject to any restrictions in this regard.

[0036] As in the Fig. 3 and Fig. 4, the support layer 3 is arranged in the interior space S. The shape of the support layer 3 is, for example, matched to the shape of the interior space S. The support layer can be brought into contact with the side wall surfaces of the first disc surface 110, the second disc surface 210, the second annular wall 22, the ribs 112, and the ribs 211. Through contact with the first disc surface 110 and the second disc surface 210, the support layer 3 can support the first disc body 1 and the second disc body 2. The support layer 3 consists, for example, of a foam that expands when heated and a colloid that dissolves when heated. There are no restrictions on the types of materials. The foam can be made of expanded microspheres, but it can be selected as needed. The volume of the support layer 3 is not particularly limited and can, for example, be a volume that fills the entire interior space S.This construction allows the first disc body 1 and the second disc body 2 to be connected to each other by means of the support layer 3 during assembly.

[0037] Fig. 6 shows a flow chart of the manufacturing method according to an embodiment of the transmission sprocket for bicycles according to the invention. As in Fig. 6, an embodiment of the present invention provides a method of manufacturing a transmission sprocket for bicycles, comprising the following steps: Step S1: Arranging a support layer consisting of a third non-metallic material on at least one of the first disc body consisting of a first non-metallic material and the second disc body consisting of a second non-metallic material. Step S2: Connecting the first disc body and the second disc body to form an interior space, with the supporting layer located in the interior space. Step S3: Heating the first disc body, the second disc body and the supporting layer, whereby the first disc body and the second disc body are bonded together and the supporting layer expands to fulfill the supporting function in the interior.

[0038] The method for manufacturing a transmission sprocket for bicycles described above can be used to manufacture the transmission sprocket for bicycles 100 described above.

[0039] It is based on the Fig.1 to 6. In the present embodiment, in step S1, the support layer 3 expands due to heat to fulfill the support function in the interior space S after the support layer 3 has been arranged in the recesses 111 of the first pane body 1 and on the second pane surface 210 of the second pane body 2. In other embodiments, however, the non-expanding support layer 3 can be arranged only on the first pane body 1 or the second pane body 2.

[0040] In the present embodiment, in step S2, the first disk body 1 and the second disk body 2 are respectively arranged on a male and female die (not shown) and then brought into contact with each other by docking the male and female dies. However, the detailed arrangement method can be changed as needed.

[0041] In the present embodiment, in step S3, the first disc body 1, the second disc body 2 and the non-expanding support layer 3 are heated by heating a mold.

[0042] There are no particular restrictions regarding the state of the base layer 3 before expansion, and it can be solid, liquid, film, or coating. The timing of the arrangement of the teeth 1a can be before step S1, after step S3, or between any two steps between step S1 and step S3.

[0043] In the present embodiment, no additional adhesive is applied to the first pane body 1 and the second pane body 2 besides the support layer 3. More specifically, in the present embodiment, in step S3, the first pane body 1 and the second pane body 2 can be heated in the assembled state by a heatable mold. This results in a part of the first pane body 1 and the second pane body 2 melting, and the parts that come into contact with each other are bonded together. However, the present invention is not subject to any restrictions in this regard.

[0044] By the above method, the support layer 3 can be uniformly arranged on the first disc body 1 and the second disc body 2 before the first disc body 1 and the second disc body 2 are bonded together. Therefore, the positions of the support layer 3 after expansion are relatively evenly distributed. Compared with the method in which the support layer 3 is additionally injected into the interior space S, in the present embodiment, the support layer 3 is less likely to exert uneven stress on different positions of the first disc body 1 and the second disc body 2, thereby preventing deformation of the first disc body 1 and the second disc body 2. Since the first disc body 1 and the second disc body 2 are contained in and supported by a mold, the first disc body 1 and the second disc body 2 are less likely to deform when the support layer 3 expands.This method also does not require any additional holes in the first disc body 1 and second disc body 2, which are normally provided for introducing the support layer 3 from the outside into the interior space S, which increases the structural integrity and strength of the first disc body 1 and the second disc body 2 and makes the addition of seals unnecessary.

[0045] Based on the above description, the bicycle transmission sprocket and its manufacturing method according to an embodiment of the present invention have the advantage that the first disc body and the second disc body are lightweight due to the use of non-metallic materials. By disposing the support layer made of a non-metallic material in the internal space enclosed by the first disc body and the second disc body, the first disc body and the second disc body can be supported by the support layer. In this way, the structural strength of the bicycle transmission sprocket can be increased while maintaining the advantage of lightweight.

[0046] The above description represents only a preferred embodiment of the invention and is not intended to limit the claims. All equivalent changes and modifications that can be made by one skilled in the art in accordance with the description and drawings of the invention are within the scope of the present invention. The scope of the invention is defined by the appended claims. List of reference symbols 100 transmission sprocket for bicycles 1 first disc body 1a tooth 11 first disc wall 110 first disc surface 111 Deepening 112 Rib 12 first ring wall 13 Fastening section 2 second disc body 21 second disc wall 210 second disc surface 211 Rib 211a gap 212 first ring section 213 second ring section 22 second ring wall 3 Base layer 4 Spider 41 connecting hole 5 sprocket 6 Climbing aid S interior A central axis AA cut S1 step S2 step S3 step

Claims

[1] A transmission sprocket for bicycles, comprising: a first disc body made of a first non-metallic material and having a plurality of teeth on the outer circumference; a second disc body made of a second non-metallic material, which covers one side of the first disc body and together with the first disc body forms an annular interior space; and a support layer consisting of a third non-metallic material located in the interior, wherein the third non-metallic material is different from the first non-metallic material and the second non-metallic material. [2] A transmission sprocket for bicycles according to claim 1, wherein a plurality of ribs are provided on the inner space side of the first disc body or the second disc body, said ribs extending along the radial direction of the transmission sprocket and dividing the inner space into a plurality of separation chambers. [3] A transmission sprocket for bicycles according to claim 2, wherein the first disc body has a first disc surface and a first annular wall protruding from the first disc surface. [4] A transmission sprocket for bicycles according to claim 3, wherein the second disc body has a second disc surface and a second annular wall protruding from the second disc surface, the first annular wall and the second annular wall abutting against each other. [5] A transmission sprocket for bicycles according to claim 4, wherein the first disc body has a central axis, the first disc surface, the second disc surface of the second disc body and the first annular wall or the second annular wall together form an inner space, the distance between the first disc surface and the second disc surface gradually decreasing along a radial direction from the first annular wall to the direction away from the central axis. [6] A transmission sprocket for bicycles according to claim 1, wherein the first non-metallic material and the second non-metallic material are fiber composite materials and the third non-metallic material is a foam. [7] A transmission sprocket for bicycles according to claim 6, wherein the first non-metallic material and the second non-metallic material are made of the same material. [8] A transmission sprocket for bicycles according to claim 1, wherein the first disc body and the second disc body are integrally formed.

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