| 摘要 |
1321235 Racket handle DUNLOP HOLDINGS Ltd 23 Oct 1970 [29 Oct 1969] 52861/69 Heading A6D A racket, e.g. for badminton, includes a tubular shaft having a section tapering towards the racket head so that, when the handle is clamped and the head is loaded, the surface stress of the shaft at the narrower end is in the range 80-110% of that at the wider end. The stress when so loaded may be substantially the same or may vary uniformly along the tapered section. The shaft may include a section tapering in the opposite sense, a parallel sided section connecting the narrow ends of the two tapered sections, and parallel sided sections at either end. The shaft may be of e.g. steel, aluminium or plastics reinforced with fibreglass or carbon fibres and may be produced by rotary swaging of a tube of uniform internal and external diameters. The tapered section may be stepped and its wall thickness may vary. Examples of shafts including their dimensions and flexural rigidity are given. |
