| 摘要 |
A composite bicycle tire rim constructed from layers or plys of a fiber reinforcement, preferably fiber glass, to provide a rim that has a weight that is comparable to an aluminum rim and as is strong as a steel rim. The composite rim is continuous, is formed as a hooked bead type rim to have inwardly pointing side wall hook ends that are for fitting into grooves formed in a tire side walls, mounting the tire thereto. The rim is formed on a circular mandrel by laying up groups of plys thereon, with four (4) plys of fiber glass laid up for each group. In which laying up, a first ply of the four plys is fitted onto the mandrel to where its fiber angle is parallel to the mold mandrel circumference, with a following ply laid thereon at a selected positive angle to a vertical axis, and a next ply is laid thereon at a negative angle to the vertical axis, and with a final ply of each group laid thereon to have its fibers perpendicular to a tangent to the mold circumference. Which fiber placement, for each group, creates a balanced laminate, without residual stress, that is not subject to dimensional deformity. The mandrel with the groups of fiber glass plys thereon, is placed in a mold cavity, wherein the laminate is subjected to heat and pressure to cure it into the composite rim that is removed from the mold and the mandrel cross section is reduced to allow it to be removed from between the rim hook ends. Which hook ends are machined to a desired length from the rim side walls inner surfaces, and the rim is coated with a urethane polymer to enhance the overall rim strength and provide an attractive surface finish.
|
