| 摘要 |
The invention relates to hollow frames for games rackets e.g. for squash and badminton, which are in the form of hollow injection moldings of thermoplastics material and to a method of making such frames involving injecting the thermoplastics material around a fusible core that can be subsequently melted out. For rackets such as for squash and badminton with relatively long thin shafts undesirable displacement of the shaft portion (22) of the core under molding pressure is achieved by use of locating means (24A,25A) that form holes that do not weaken the eventual shaft (23). The means are positioned to correspond to the neutral surface of the shaft and such that the greatest unclamped length of shaft core between supports divided by the depth of the shaft core is less than 10. |
