| 摘要 |
<p>The invention relates to a hollow racket frame, e.g. for tennis, made by injection moulding of reinforced thermoplastics material. The frame has a head and handle portions and pairs of integrally-formed stringing holes (26, 27) are in the outer circumference (23) and are in the inner circumference (22) of the head respectively. Each stringing hole is defined by an integrally-moulded reinforcing tubular projection (24, 25) projecting inwardly of the hollow frame. The two opposed projections are of insufficient length to meet inside the hollow frame. The integrally-formed holes and tubular projections are made using suitably shaped mould pins (15) passing through holes in a fusible mould core (10) around which the thermoplastics material is injected. Pins (15) are a tight fit in their holes for the centrai portion of their lenght which provides positive location during moulding.</p> |
