Patent Application
20160052338
1. Field of the Invention
The present invention relates to a bicycle hub, and more particularly to a protective structure for a bicycle hub.
2. Description of Related Art
Generally, a hub cassette 7 has a plurality of ribs 71 on an outer periphery of the hub cassette 7 for engagement with a sprocket 8, as shown in
In order to solve above problem, a conventional bicycle hub further comprises a metal sheet 9 attached to the rib 71, as shown in
Another type of bicycle hub is illustrated in U.S. Pub. No. 2013/0076112. In this bicycle hub, a driving socket has a plurality of ribs extending axially on the outer surface thereof and at least one protection unit located between two of the ribs and has an engaging portion. A cover is engaged with the engaging portion and has a cover face and two sidewalls to form an engaging groove. Specifically, the engaging portion has two transmission surfaces respectively located on two sides thereof and each transmission surface is gradually tapered toward a center of the driving socket. Each of the two sidewalls of the cover has an inclined surface corresponding to the respective transmission surface of the engaging portion for engagement between the engaging groove of the cover and the engaging groove. Furthermore, two sides of the engaging portion each has a positioning slot in the outer surface of the driving socket, wherein each sidewall of the cover has an extension engaged with the positioning slot to increase the contact area between the cover and the engaging portion. However, the configurations of the transmission surface and the positioning slot of the engaging portion will reduce the strength of the driving socket. Besides, the manufacturing processes of the engaging portion and the cover will increase manufacturing cost.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional bicycle hub.
The main objective of the present invention is to provide an improved bicycle hub.
To achieve the objective, a bicycle hub comprises a hub cassette and at least one protective member. The hub cassette has a driving portion and a shell portion connected to the driving portion. The shell portion has a plurality of ribs integrally formed on an outer periphery of the shell portion and extending axially from one end of the shell portion to the other end of the shell portion. The protective member is made of harder material than that of the ribs. The protective member is attached to at least one of the ribs of the shell portion. The protective member has a U-shaped cross section and defines a top wall and two side walls extending from a bottom of the top wall. The top wall and the two side walls define an engaging groove. Specifically, an inner angle of the engaging groove between the top wall and each of the side walls is an acute angle originally. Wherein each of the two side walls of the protective member is flexible relative to the top wall of the protective member such that the two side walls of the protective member clamp two lateral walls of the associated rib.
Preferably, the bicycle hub further comprises another two protective members attached to the ribs of the shell portion, and the three protective members are disposed in triangular arrangement.
Another object in accordance with the present invention is the provision of a method for manufacturing the bicycle hub above.
The method comprises the steps of (a). cutting a solid rod into a plurality of rod pieces; (b). molding each of the rod pieces into a semi-product by a mold, wherein the semi-product has a driving portion, a shell portion, and a plurality of ribs integrally formed on an outer periphery of the shell portion; (c). removing excess material of the semi-product to form a hollow structure; (d). anodizing a surface of the semi-product to form a final product; and (e). attaching at least one protective member to a related one of the ribs of the shell portion, the protective member made of harder material than that of the ribs and having a U-shaped cross section and defining a top wall and two side walls extending from a bottom of the top wall, the top wall and the two side walls defining an engaging groove, wherein an inner angle of the engaging groove between the top wall and each of the side walls being an acute angle originally, and the two side walls of the protective member are flexible to clamp two lateral walls of the associated rib.
Preferably, in step (e), an installation of the protective member is manual, semi-automatic or fully automatic. In addition, another two protective members are attached to the ribs of the shell portion such that the three protective members are disposed in triangular arrangement. Moreover, in step (c), the hollow structure of the semi-product defines an assembling hole therethrough from the shell portion to the driving portion axially.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
Referring to
The hub cassette 1 has a driving portion 12, a shell portion 11 connected to the driving portion 12 and a flange 13 defined between the shell portion 11 and the driving portion 12. The driving portion 12 of the hub cassette has a plurality of recesses 121 around an outer periphery thereof. The shell portion 11 has a plurality of ribs 14 integrally formed on an outer periphery of the shell portion 11 and extending axially from one end of the shell portion 11 to the other end of the shell portion 11. The protective member 2 is made of harder material than that of sprockets and the hub cassette especially the ribs 14. The protective member 2 is attached to at least one of the ribs 14 of the shell portion 11. The protective member 2 has a U-shaped cross section and defines a top wall 23 and two side walls 22 extending from a bottom of the top wall 23. The top wall 23 and the two side walls 22 form an engaging groove 21.
Specifically, an inner angle of the engaging groove 21 between the top wall 23 and each of the side walls 22 is an acute angle originally, wherein each of the two side walls 22 of the protective member 2 is flexible relative to the top wall 23 of the protective member 2 such that the two side walls 22 of the protective member 2 clamp two lateral walls of the associated rib 14. In this manner, the protective member 2 is fitted on the associated rib 14, and the inner angle between the top wall 23 and each side wall 22 is consistent with the angle of the associated rib 14 finally. In the embodiment of the present invention, the angle between the top wall 23 and each side wall 22 is changed to a right angle.
Moreover, the number of the protective member 2 is not limited in the present invention. For instance, the bicycle hub could further comprises another two protective members 2 such that the three protective members 2 are attached to the ribs 14 of the shell portion 11, and the three protective members 2 are disposed in triangular arrangement. Furthermore, the hub cassette 1 is hollow cylindrical in shape which defines an assembling hole 15 therethrough.
Referring to
In step 101, a solid rod 3 is cut into a plurality of rod pieces 31, firstly.
In step 102, each of the rod pieces 31 is molded into a semi-product 32 by a mold 5, wherein the semi-product 32 is formed with a driving portion 12, a shell portion 11, and a plurality of ribs 14 integrally formed on an outer periphery of the shell portion 11.
In step 103, excess material of the semi-product 32 is removed to form a hollow structure which defines an assembling hole 15 therethrough from the shell portion 11 to the driving portion 12 axially.
In step 104, a surface of the semi-product 32 is anodized to form a final product.
Finally, in step 105, at least one protective member 2 is attached to a related one of the ribs 14 of the shell portion 11.
As mentioned previously, the two side walls 22 of the protective member 2 are flexible relative to the top wall 23.
Although embodiments of this invention have been fully described with reference to the accompanying drawings, it is to be understood that various modifications can be made by those skilled in the art without departing from the scope of the invention as hereinafter claimed.
