Front frame for a bicycle

Information

  • Patent Application
  • 20080018075
  • Publication Number
    20080018075
  • Date Filed
    October 04, 2006
    18 years ago
  • Date Published
    January 24, 2008
    17 years ago
Abstract
A front frame for a bicycle includes an upper tube, a lower tube and a head tube all of which are made of fiber reinforced material. The head tube extends integrally from a front end of the upper tube and a front end of the lower tube. The head tube has a chamber communicates with a chamber of the upper tube and a chamber of the lower tube. Two inner tubes are provided in the chamber of the upper tube. The abutted portions of the two inner tubes form a rib such that the structure strength of the upper tube is improved.
Description

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is an explosive view of the frame of a conventional bicycle.



FIG. 2 is a sectional view along the 2-2 line in FIG. 1.



FIG. 3 is a front view of a preferred embodiment of the present invention.



FIG. 4 is a sectional view along the 4-4 line in FIG. 3.



FIG. 5 is a sectional view along the 5-5 line in FIG. 3.



FIG. 6 is a sectional view along the 6-6 line in FIG. 3.





DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 3, a front frame 10 for a bicycle in accordance with the preferred embodiment of the present invention is shown comprising an upper tube 20, two first inner tubes 24, a lower tube 30, two second inner tubes 34 and a head tube 40 all of which are made of fiber reinforced resin material. The fiber can adopt but not restrict to carbon fiber, glass fiber, boron fiber or Kevlar® fiber. The resin can adopt thermosetting resin or thermoplastic resin.


As shown in FIGS. 4-6, the upper tube 20, the lower tube 30 and the head tube 40 are formed integrally. The upper tube 20 has a chamber 22 therein. The two first inner tubes 24 abut together and are disposed in the chamber 22 of the upper tube 20. The upper tube 20 and the two first inner tubes 24 are closely contacted without a gap therebetween. The abutted portions of the first inner tubes 24 form an upper rib 26. The lower tube 30 has a chamber 32 therein, too. The two second inner tubes 34 abut together and are disposed in the chamber 32 of the lower tube 30. The lower tube 30 and the two second inner tubes 34 are closely contacted without a gap therebetween. The abutted portions of the second inner tubes 34 form a lower rib 36.


The head tube 40 extends integrally from a front end of the upper tube 20 and a front end of the lower tube 30. The upper tube 20, the head tube 40 and the lower tube 30 are disposed at a same plane P. The upper rib 26 of the upper tube 20 is parallel to the plane P. The lower rib 36 of the lower tube 30 is parallel to the plane P, too. The head tube 40 has a chamber 42 for receiving an upright tube 50 of a front fork (not shown), and two openings 44 communicating the chamber 42 with outside. The chamber 42 of the head tube 40 communicates with the chamber 22 of the upper tube 20 and the chamber 32 of the lower tube 30. The first inner tubes 24 each have an inside communicates with the chamber 42 of the head tube 40, and the second inner tubes 34 each have an inside communicates with the chamber 42 of the head tube 40, too.


The front frame 10 is manufactured by the following steps. First, abut the two first inner tubes 24 together and abut the two second inner tubes 34 together. Then wind multiple layers of pre-pregs around the two first inner tubes 24 to form the upper tube 20, and wind multiple layers of pre-pregs into the head tube 40 at the front end of the upper tube 20, and wind multiple layers of pre-pregs around the two second inner tubes 34 to form the lower tube 30. Finally, place the combination into a die (not shown) and inflate the two first inner tubes 24, the two second inner tubes 34 and the head tube 40 with high pressure air to make the two first inner tubes 24 (or two second inner tubes 34) join with the upper tube 20 (or the lower tube 30) tight on the one hand, and to make the upper tube 20, the lower tube 30 and the head tube 40 abut on the inner wall of the die on the other hand. Then cure the combination to form the front frame 10.


Since the front frame 10 is cured only once, there is no crack generated between the first inner tube 24 (or two second inner tubes 34) and the upper tube 20 (or the lower tube 30). The structure strength of the front frame 10 is improved. Besides, since the upper tube 20 has the upper rib 26 inside and the lower tube 30 has the lower rib 36 inside, the structure strength of the upper tube 20 and the lower tube 30 are improved. Under the premise that the structure strength of the front frame 10 is enough, the quantity of the pre-pregs used in the front frame 10 can be reduced such that the weight of the front frame 10 can be decreased. The weight of the front frame 10 of the present invention is further decreased since the front frame 10 does not have the cured tube 9 in the conventional structure. Therefore, the front frame 10 of the present invention can improve the drawback of the conventional structure and achieve the objective of the present invention.


In practice, the structure of the front frame 10 has other alternatives. For example, the extending direction of the upper rib 26 and the lower rib 36 can be changed according to user's demand. The upper rib 26 or the lower rib 36 may also not present. Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention.

Claims
  • 1. A front frame for a bicycle, comprising: an upper tube made of fiber reinforced material and having a chamber therein;a lower tube made of fiber reinforced material and having a chamber therein; anda head tube made of fiber reinforced material and extending integrally from an end of the upper tube and an end of the lower tube; wherein the upper tube, the lower tube and the head tube are disposed substantially at a same plane, and the head tube has a chamber and two openings communicating the chamber with outside, and the chamber of the head tube communicates with the chamber of the upper tube and the chamber of the lower tube.
  • 2. The front frame for a bicycle as claimed in claim 1, further comprising two first inner tubes abutted together and disposed in the chamber of the upper tube, wherein the upper tube and the two first inner tubes are closely contacted without a gap therebetween, and the abutted portions of the first inner tubes form an upper rib.
  • 3. The front frame for a bicycle as claimed in claim 2, wherein an inside of the first inner tube communicates with the chamber of the head tube.
  • 4. The front frame for a bicycle as claimed in claim 2, wherein the upper rib is substantially parallel to the plane.
  • 5. The front frame for a bicycle as claimed in claim 1, further comprising two second inner tubes abutted together and disposed in the chamber of the lower tube, wherein the lower tube and the two second inner tubes are closely contacted without a gap therebetween, and the abutted portions of the second inner tubes form an lower rib.
  • 6. The front frame for a bicycle as claimed in claim 5, wherein an inside of the second inner tube communicates with the chamber of the head tube.
  • 7. The front frame for a bicycle as claimed in claim 5, wherein the lower rib is substantially parallel to the plane.
Priority Claims (1)
Number Date Country Kind
95213022 Jul 2006 TW national