| 摘要 |
<p>Beam having a variable degree of rigidity, produced from reinforced synthetic material, has a cross-section representing the profile of an inverted "U". Beam keeps pace with the developments in associated spheres for the redn. of wt. and is ideally suited for forming the frame of a child's or adult's bicycle. For a pedalled bicycle, legs of the "U" are 10-15 cm long whilst in a frame for a moped, the legs are 12-20 cm long. Materials are selected from polypropylene, polyamides, polycarbonates, polyesters, acrylonitrile resins, etc. Reinforcement consists of 20-40 wt.% of glass fibres, metal fibres, mineral fibres and mixts. Material has a density greater than 0.8.</p> |
