| 摘要 |
<p>A method of moulding a double-walled socket is achieved by forming a mould cavity 22 by inserting a male mould element into a female mould element. The mould is charged by introducing particulate material (thermoplastic powder) through filler pipes 28 into cavity 22 and then rotated whilst being heated to distribute the material along internal surfaces of cavity 22 so that the moulded product forms in the cavity 22. The mould is cooled and the male element removed from the female element to release the moulded socket. The shrinkage distortion and surface unevenness of the socket bore is reduced in such a double walled socket. A spigot having axially spaced annular walls which mate with corresponding walls in the socket provides an assembly which is easily releasable. The mould may also be rocked about an axis as it is rotated. A bollard 2 and a socket 1 to be used in combination may be so produced. <IMAGE></p> |
