Chain cover for bicycle and bicycle comprising same

Abstract

[Problem] To provide a chain cover that can easily be attached and detached by a user. [Solution] A chain cover 1 comprises an inner shell 2 that is coupled to a bottom bracket B2 of a pedal system B1 of a bicycle B, and an outer shell 3 that is coupled to the inner shell 2 and covers the outer side of a chain B3. The outer shell 3 has two pairs of band-receiving holes 51, 52 that serve as band-receiving parts for winding and coupling bands 41, 42 to a seat stay B4 and a chain stay B5.

Description

Bicycle Chain Cover and Bicycle Equipped with the Same

[0001] The present invention relates to a bicycle chain cover and a bicycle equipped with the same.

[0002] Usually, a bicycle chain cover is one that is attached at the time of selling a bicycle. Even if there is an aftermarket chain cover, there has been no chain cover premised on being detached and attached by the user side. For example, Patent Document 1 discloses a chain cover 58 assumed to be attached at the time of selling.

[0003] Japanese Patent Application Laid-Open No. 2015-009671

[0004] From the perspective of safety, it is better to attach a chain cover, but there are also cases where it is more preferable to remove it from the design perspective. Also, when transferring between siblings, for example, the older brother may not need a chain cover while the younger sister may need a chain cover to avoid getting her skirt caught.

[0005] However, it was technically difficult for the user to attach and detach the chain cover by himself / herself as it was necessary to adjust the relative positions of multiple fixing points.

[0006] In particular, when the pedal system moves back and forth to adjust the tightness of the chain, the chain cover also needs to move accordingly. Therefore, it was necessary to attach and detach the chain cover every time the chain was adjusted, and there was also a problem that the position required complicated adjustment. Also, in order to accommodate the forward and backward movement of the chain cover, an adjustment mechanism such as a long hole was required, but such a mechanism had a concern of structurally impairing the durability of the material.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a chain cover that can be easily attached and detached by the user.

[0008] To achieve the above objective, the present invention provides a bicycle chain cover comprising an inner shell connected to the bicycle's pedal system and an outer shell connected to the inner shell and covering the outside of the chain, wherein the outer shell has a band receiving portion for wrapping and connecting a band to a seat stay or chain stay.

[0009] Preferably, the band receiving portion is a seat stay band receiving portion and a chain stay band receiving portion, corresponding to the seat stay and chain stay, respectively.

[0010] Preferably, the inner shell has a substantially C-shaped bottom bracket receiving hole for receiving the bottom bracket, and a fixing screw through hole provided at the end of the bottom bracket receiving hole for fixing the inner member to the bottom bracket by tightening the bottom bracket receiving hole with a fixing screw that penetrates vertically.

[0011] Preferably, the outer shell has projections protruding inward from its upper end, lower end, and front end, and the inner shell has receiving grooves that slide to receive the projections at the upper and lower ends, and a receiving hole that receives the projection at the front end.

[0012] According to the present invention, a chain cover can be provided that can be easily attached and detached by the user using only one fixing screw and a band.

[0013] This is an exploded perspective view showing a chain cover according to an embodiment of the present invention. This is an exploded perspective view showing the chain cover of Figure 1 viewed from the opposite side. This is a perspective view showing the chain cover of Figure 1 installed on a bicycle. This is a side view showing the chain cover of Figure 1 installed on a bicycle. This is a right side view showing the chain cover of Figure 1 in a connected state. This is a left side view showing the state of Figure 5. This is a top view showing the state of Figure 5. This is a bottom view showing the state of Figure 5. This is a front view showing the state of Figure 5. This is a rear view showing the state of Figure 5. This is an inside perspective view showing the state of Figure 5. This is an outside perspective view showing the state of Figure 5. This is an inside perspective view showing the inner shell before installation, showing the installation method. This is an inside perspective view showing the inner shell after installation, showing the installation method. This is a right side view showing the outer shell of Figure 1. This is a left side view showing the state of Figure 15. This is a top view showing the state of Figure 15. This is a bottom view showing the state of Figure 15. This is a front view showing the state of Figure 15. This is a rear view showing the state of Figure 15. This is a right side view showing the inner shell of Figure 1. This is a left side view showing the state of Figure 21. This is a top view showing the state of Figure 21 with the fixing screws and nuts attached. This is a bottom view showing the state in Figure 23. This is a front view showing the state in Figure 21. This is a perspective view showing the state in Figure 23. This is an enlarged perspective view of the band receiving hole portion of the outer shell. This is an enlarged perspective view of the inner shell. This is a perspective view showing the chain cover of Figure 1 attached to a bicycle. This is a schematic front view showing the state in Figure 29. This is a cross-sectional view of Figure 29 taken in the horizontal plane. This is a perspective view showing the state in Figure 29 without the outer shell attached.

[0014] Embodiments of the present invention will now be described in detail with reference to the drawings. Figure 1 is an exploded perspective view showing a chain cover according to an embodiment of the present invention. In the following description, the front wheel side of the bicycle will be referred to as the front, and the rear wheel side as the rear. In Figure 1, the right side is the front.

[0015] An embodiment of the present invention provides a chain cover 1 for a bicycle, comprising an inner shell 2 that connects to the bottom bracket B2 of the pedal system B1 of a bicycle B, and an outer shell 3 that connects to the inner shell 2 and covers the outside of the chain B3. The outer shell 3 has two pairs of band receiving holes 51, 52 as band receiving parts for wrapping and connecting bands 41, 42 to the seat stay B4 and chain stay B5.

[0016] More specifically, the band receiving holes 51 and 52, which serve as band receiving sections, are a pair of seat stay band receiving holes 51 and a pair of chain stay band receiving holes 52, corresponding to the seat stay B4 and chain stay B5, respectively. There is a gap between the pair of seat stay band receiving holes 51, and the seat stay B4 is positioned in this gap. Also, there is a groove between the pair of chain stay band receiving holes 52 when viewed from the inside, and the chain stay B5 is positioned in this groove. In this state, the outer shell 3 is fixed to the seat stay B4 and chain stay B5 by passing the so-called cable ties 41 and 42, which serve as bands, through the pair of seat stay band receiving holes 51 and the pair of chain stay band receiving holes 52 and tightening them in an annular shape.

[0017] The inner shell 2 preferably has a roughly C-shaped bottom bracket receiving hole 21 for receiving the bottom bracket B2, and a fixing screw through hole 24 provided at the end of the bottom bracket receiving hole 21, extending from the upper and lower ends, for fixing the inner member 2 to the bottom bracket B2 by tightening the bottom bracket receiving hole 21 with a fixing screw 23 and nut 23b that penetrates vertically. It is more preferable if the nut 23b is integrally molded with the corresponding hole in the inner shell, as this allows the user to tighten the fixing screw 23 without needing to hold the nut 23b.

[0018] The outer shell 3 has projections 61, 62, and 63 that protrude inward from the upper end, lower end, and front end, respectively, while the inner shell 2 has an upper receiving groove 71 and a lower receiving groove 72 that receive the upper end projection 61 and the lower end projection 62 while sliding, and a front receiving hole 73 that receives the front end projection 63.

[0019] The outer shell 3 is also an elongated oval shape that covers the chain B3 as a whole, and has a front hole 8 through which the crank of the pedal system B1 is inserted, and a rear hole 9 through which the rear wheel axle is inserted. More specifically, as shown in Figure 15, the rear hole 9 is divided into a front rear hole 9b in front of the seat stay band receiving hole 51 and a rear rear hole 9a behind the seat stay band receiving hole 51.

[0020] The method for attaching the chain cover 1, configured as described above, to bicycle B will now be explained. As shown in Figure 13, the inner shell 2 is installed on the bottom bracket B2. The inner member 2 is then fixed to the bottom bracket B2 by tightening the bottom bracket receiving hole 21 with a fixing screw 23 and nut 23b that penetrates perpendicularly through the fixing screw through hole 24.

[0021] Next, the outer shell 3 is engaged with the inner shell 2. Specifically, as shown in Figure 32, the outer shell 3 is positioned opposite the inner shell 2, and the upper end projection 61 and lower end projection 62 are positioned at the ends of the upper receiving groove 71 and lower receiving groove 72. The outer shell 3 is then engaged with the inner shell 2 by sliding it so that the upper end projection 61 and lower end projection 62 pass through the upper receiving groove 71 and lower receiving groove 72. In this state, the front end projection 63 enters the front receiving hole 73, thereby engaging the outer shell 3 with the inner shell 2.

[0022] Next, the seat stay B4 is positioned in the gap between the pair of seat stay band receiving holes 51. The chain stay B5 is positioned in the groove between the pair of chain stay band receiving holes 52. In this state, the so-called cable ties 41 and 42 are passed through the pair of seat stay band receiving holes 51 and the pair of chain stay band receiving holes 52 and tightened in a ring shape. This secures the outer shell 3 to the seat stay B4 and chain stay B5.

[0023] Figure 27 is an enlarged perspective view of the band receiving holes 51 and 52 in the outer shell 3. Each of the band receiving holes 51 and 52 has a receiving recess 51a and 52a in one of the holes for accommodating the head portion of the cable tie. Cable ties have a head portion for locking the end, and after cutting off the excess portion of the end that is locked to the head portion, the cut portion may protrude slightly from the head portion. However, by accommodating the head portion and the excess portion in such receiving recesses 51a and 52a, safety can be enhanced, the appearance can be improved, and the situation where the head portion comes off due to impact, such as when the bicycle falls over, can be avoided.

[0024] Figure 28 is an enlarged perspective view of the inner shell 2. The inner shell 2 is provided with opposing engaging protrusions 25a and 25b above and below the bottom bracket receiving hole 21 for engaging with the bottom bracket B2. The distance between these protrusions is slightly smaller than the outer diameter of the bottom bracket B2. By applying a small amount of force to fit the inner shell 2 onto the bottom bracket B2, the elastic deformation of the inner shell 2 material causes the distance between the engaging protrusions 25a and 25b to widen, allowing the bottom bracket B2 to be received in the bottom bracket receiving hole 21. When the fixing screw 23 is lightly tightened in this state, the inner shell 2 is initially positioned to be slightly rotatable relative to the bottom bracket B2.

[0025] Furthermore, a positioning recess 26 is provided above the bottom bracket receiving hole 21 of the inner shell 2. As shown in Figures 29, 30, and 31, the right side portion B21 of the plate-shaped connecting member extending to the top of the bottom bracket B2 abuts against and engages with the positioning recess 26, thereby positioning the inner shell 2 in the rotational direction relative to the bottom bracket B2. In this state, the fixing screw 23 is tightened securely, completely positioning and fixing the chain cover 1 to the bottom bracket B2. In this way, even an amateur can easily position and safely install the chain cover 1. Furthermore, bicycle B has a mechanism that allows the chain tension to be adjusted by adjusting the adjustment screw B23 while the horizontal screw B22 is loosened, thereby adjusting the front-to-back position of the bottom bracket B2. However, even with such a mechanism, the chain cover 1 can be positioned and fixed only to the bottom bracket B2 and does not need to be fixed to other parts of bicycle B. Therefore, when adjusting the chain tension, it is only necessary to cut the cable ties 41 and 42, remove the outer shell 3 if necessary, adjust the chain tension, and then reattach the cable ties 41 and 42, making it easy and flexible to change the position in the front-to-back direction. In addition, as shown in Figure 32, even when the front sprocket cover S is attached, the inner shell 2 and outer shell 3 can be configured so that they do not come into contact with the cover S and do not interfere with rotation.

[0026] As described above, the chain cover 1 can be fixed to the bicycle B with only one screw and two cable ties, and when removing it, only the cable ties need to be cut and the screw removed, so it can be easily attached and detached by the user without requiring advanced skills or tools. In addition, the cable ties prevent the chain cover 1 from coming off the bicycle B, but allow the chain cover 1 to move slightly in the length direction, i.e., in the front-to-back direction, of the seat stay B4 and chain stay B5. Therefore, even if the user adjusts the chain tension by slightly moving the pedal system B1 back and forth, the chain cover 1 can be fixed again without removing it and without requiring advanced skills or tools, by cutting the cable ties, or by cutting the cable ties once, adjusting, and then reattaching them. Furthermore, even if the outer shell 3 is made of a brittle material such as polycarbonate, if it is joined to the frame with cable ties, it is less likely to crack compared to, for example, if it is screwed to the main body. In addition, because it can be made of a lightweight material such as polycarbonate, a lightweight and strong chain cover can be constructed even when designed to cover not only the upper half of the chain but the entire chain.

[0027] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and applications are possible within the scope of the claims.

[0028] For example, the shape of the chain cover 1 is not limited to the shape of the embodiment described above, and various shapes can be adopted.

[0029] Furthermore, the bicycle B having the chain cover 1 of the present invention can be a variety of bicycles, including general-purpose bicycles, children's bicycles, balance bikes without pedals, sports bicycles, electric assist bicycles, tricycles, and special bicycles.

[0030] 1 Chain cover 2 Inner shell 3 Outer shell B Bicycle

Claims

1. A chain cover for a bicycle, comprising an inner shell that connects to the pedal system of the bicycle, and an outer shell that connects to the inner shell and covers the outside of the chain, wherein the outer shell has a band receiving portion for wrapping and connecting a band to a seat stay or chain stay.

2. The chain cover according to claim 1, wherein the band receiving portion is a seat stay band receiving portion and a chain stay band receiving portion, corresponding to the seat stay and the chain stay, respectively.

3. The chain cover according to claim 1 or 2, wherein the band receiving portion has a receiving recess for accommodating the head portion of a cable tie.

4. The chain cover according to claim 1, wherein the inner shell has a substantially C-shaped bottom bracket receiving hole for receiving a bottom bracket, and a fixing screw through hole provided at the end of the bottom bracket receiving hole for fixing the inner member to the bottom bracket by tightening the bottom bracket receiving hole with a fixing screw that penetrates vertically.

5. The chain cover according to claim 4, wherein the receiving hole is provided with opposing engaging projections above and below it for engaging with the bottom bracket.

6. The chain cover according to claim 5, wherein the distance between the engaging protrusions is smaller than the outer diameter of the bottom bracket.

7. The chain cover according to any one of claims 4 to 6, wherein a positioning recess is provided above the bottom bracket receiving hole of the inner shell for engaging with a plate-shaped connecting member extending to the upper part of the bottom bracket.

8. The chain cover according to any one of claims 1 to 7, wherein the outer shell has projections protruding inward from its upper end, lower end, and front end, and the inner shell has a receiving groove for receiving the projections at the upper and lower ends while sliding, and a receiving hole for receiving the projection at the front end.

9. A bicycle comprising a chain cover according to any one of claims 1 to 8.

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