Patent Application
20200070573
The present invention relates to a hub shaft, and more particularly to a bicycle hub shaft structure.
Generally, the bicycle hub shaft is inserted in a sprocket seat, and the outer edge of the sprocket seat is provided with a plurality of sprockets. The conventional bicycle hub shaft is made of lighter weight materials in order to maintain the advantage of lightweight. In addition, in order to meet the needs of the bicyclists, the range of bicycle speed change becomes more and more wide, and the number of bicycle shifting sections is also increased, so that the number of the sprockets mounted on the sprocket seat is also increased, which applies greater load on the bicycle hub shaft. In this case, the bicycle hub shaft often breaks due to the large load.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.
One objective of the present invention is to provide a bicycle hub shaft structure capable of improving the strength of the bicycle hub shaft and the load capacity of the sprocket seat as well.
To achieve the above objective, a bicycle hub shaft structure in accordance with the present invention comprises:
a first shaft section made of a first material and used to insert into a sprocket seat, wherein the first shaft section is a hollow cylinder and has a first end, an opposite second end, and a first through hole running through the first end and the second end; and
a second shaft section made of a second material, wherein a strength of the first material is stronger than that of the second material, the second shaft section is a hollow cylinder and includes: a third end, an opposite fourth end, and a second through hole running through the third and fourth ends, the second end of the first shaft section is connected to the third end of the second shaft section, so that the first and second through holes are in communication with each other.
It can be learned from the above that the bicycle hub shaft of the invention is formed by the first and second shaft sections, instead of being integrally formed. Besides, the strength of the first shaft section is stronger than the second shaft section, so that the first shaft section inserted in the sprocket seat has a higher structural strength, thus improving the strength of the bicycle hub shaft and the load capacity of the sprocket seat as well.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.
Referring to
The first shaft section 10 is made of a first material and inserted into the sprocket seat A. The first shaft section 10 is a hollow cylinder and has a first end 11, an opposite second end 12, and a first through hole 13 running through the first end 11 and the second end 12.
The second shaft section 20 is made of a second material. The strength of the first material is stronger than that of the second material, so that the weight of the second shaft section 20 is lighter than that of the first shaft section 10. The second shaft section 20 is a hollow cylinder and includes: a third end 21, an opposite fourth end 22, and a second through hole 23 running through the third and fourth ends 21, 22. The second end 12 of the first shaft section 10 is connected to the third end 21 of the second shaft section 20, so that the first and second through holes 13, 23 are in communication with each other. The bicycle hub shaft is not integrally formed.
In this embodiment, the first material may be an iron alloy or the like, and the second material is selected from the group consisting of aluminum alloys and titanium alloys.
In the present embodiment, as shown in
In another embodiment as shown in
In a preferred embodiment, an additional adhesive is provided between the first threaded portion 14 and the second threaded portion 24 to allow the first threaded portion 14 and the second threaded portion 24 to be meshed more tightly.
It can be learned from the above that the bicycle hub shaft of the invention is formed by the first and second shaft sections 10, 20 instead of being integrally formed. Besides, the strength of the first shaft section 10 is stronger than the second shaft section 20, so that the first shaft section 10 inserted in the sprocket seat A has a higher structural strength, thus improving the strength of the bicycle hub shaft and the load capacity of the sprocket seat A as well.
Besides, the first and second shaft sections 10, 20 are coupled to each other by threads engagement, so that the centers of the first and second shaft sections 10, 20 will not be misaligned, and the bicycle hub structure of the invention can maintain precision without swaying.
In addition, the outer surface of the bicycle hub shaft has a concave-convex shape, so the bicycle hub shaft of the present invention is formed by a first shaft section 10 and a second shaft section 20, and is easier to manufacture as compared with the integrally formed bicycle hub shaft, and therefore the manufacture cost can be reduced.
While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
