Patent Application
20130181424
1. Field of the Invention The present invention relates generally to bicycle frames, and more particularly, to a reinforced bicycle frame having a rib for enhancing a structural rigidity of a bottom bracket shell of the reinforced bicycle frame.
2. Description of the Related Art
Conventional bicycle frames are generally made from a metal material, which have a strong structural strength but however a heavy weight. Because of the advantage of light weight, the bicycle frames made from carbon fiber-reinforced resins are comprehensively developed and extensively commercially used in recent years. The aforesaid bicycle frame comprises a head tube, a top tube, a down tube, a seat tube, two seat stays, two chain stays and a bottom bracket shell having a through hole for insertion by an axle of a bottom bracket. Each of two ends of the axle is connected with a crank rotatably connected with a pedal. When the pedals receive the pedaling force from the bicyclist, the bottom bracket shell may bear a stress of a certain degree, which may damage the structure of the bottom bracket shell after the bicycle frame is used for a long time. In addition, if the bottom bracket shell of the bicycle frame has an insufficient structural rigidity, when an external force exerts on the bottom bracket shell, the bottom bracket shell tends to deform to consume the pedaling force, resulting in deterioration in the transmission efficiency of the pedaling power. In case the amount of the carbon fiber-reinforced resin used for making the bicycle frame is increased to build a relatively thicker wall of the bottom bracket shell for enhancing the structural rigidity of the bottom bracket shell, the total weight of the bicycle frame increases inevitably, resulting in that the bicyclist may have a strenuous bicycle riding. Therefore, the issue of how to take an optimum balance between the weight of the bicycle frame and the structural strength of the bottom bracket shell needs to be solved in developing the bicycle frame.
The present invention has been accomplished in view of the above-noted circumstances. It is therefore the primary objective of the present invention to provide a reinforced bicycle frame having a high structural strength with a light weight so as to enhance the transmission efficiency of pedaling power.
To achieve the above-mentioned objective, the reinforced bicycle frame provided by the present invention is made from a fiber-reinforced material and comprises a bottom bracket shell, a seat tube upwardly extending from the bottom bracket shell, a down tube forwardly extending from the bottom bracket shell, two chain stays backwardly and respectively extending from the bottom bracket shell, and at least one rib. The bottom bracket shell has a periphery wall defining a chamber. The periphery wall of the bottom bracket shell has two opposite lateral sides, each of which is provided with a round tube portion that is communicated between the chamber and an outside of the bottom bracket shell. The at least one rib includes a first rib extending from one of a first junction between the seat tube and the down tube and a second junction between the seat tube and the chain stays toward the round tube portions.
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The reinforced bicycle frame 10 comprises a bottom bracket shell 20, a seat tube 22, a down tube 24, two chain stays 26 and two ribs 28, which are integrally formed as a monolithic frame. As can be seen from the drawings, the seat tube 22 extends upwardly from the bottom bracket shell 20, the down tube 24 extends forwardly from the bottom bracket shell 20, and the two chain stays 26 extend backwardly and respectively from the bottom bracket shell 20. The bottom bracket shell 20 includes a periphery wall 202 defining a chamber 204. Each of two opposite lateral sides of the periphery wall 202 is provided with a round tube portion 206 communicated between the chamber 204 and an outside of the bottom bracket shell 20. The two round tube portions 26 extend inwardly into the chamber 204 and are aligned in a line for insertion by an axle of a bottom bracket. One of the ribs 28, namely a first rib, extends from a first junction between the seat tube 22 and the down tube 24 toward the two round tube portions 206 and is connected with the round tube portions 206. The other one of the ribs 28, namely a second rib, extends from a second junction between the seat tube 22 and the chain stays 26 toward the two round tube portions 206 and is connected with the round tube portions 206. It will be appreciated that the reinforced bicycle frame 10 may be provided with only one of the ribs 28 according to an actual need.
The two ribs 28 have a little weight but can greatly enhance the structural strength or rigidity of the bottom bracket shell 20, resulting in that the bottom bracket shell 20 can not only bear a great stress without any damage in its structure but also enhance the transmission efficiency of the pedaling power because when an external force exerts on the bottom bracket shell 20, the bottom bracket shell 20 may deform slightly to consume less the pedaling force generated by the bicyclist.
It should be understood that the reinforced bicycle frame 10 disclosed in the above-mentioned preferred embodiment is given for illustration of the essential technical features of the present invention only, not to limit the scope of the present invention. According to the technical features of the present invention, the reinforced bicycle frame of the present invention may be configured in various ways. For example, as shown in
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
