| 摘要 |
<p>The basic material for prodn. of the racquet frame consists of two pieces of porous core material, rigid PU foam, or similar encased in a fibre material layer 1-2 mm thick, which is impregnated with a hard plastic in liq. form. The pieces are therefore easy to bend, and can be placed in cavities which are identically shaped in each form half, and which when assembled form the frame shape space. Two shorter basic material pieces complete the frame ring part, and before the form halves fitted with basic material pieces are assembled, four cores are positioned in the form between the basic pieces. Three of the cores are formed as combs, the pins of which form holes for the racquet strings. The core thickness is 1.5-2 m, and the width of the pins is slightly larger. The cores also form a track running around the whole ring part, in which the strings lie well-protected against mechanical effect.</p> |
