| 摘要 |
1290548 Moulding pipe socket ends DYNAMIT NOBEL AG 7 Nov 1969 [9 Nov 1968] 54743/69 Heading B5A [Also in Division F2] A socket 3 is formed at an end of a heated polyvinyl chloride pipe 1, having circumferentially or helically directed external ribs 2, by axially introducing a heated rotating mandrel to expand the pipe 1 to the required socket dimension, then cooling the pipe with the mandrel 4 stationary, and thereafter rotating the mandrel 4 during its axial withdrawal from the socket 3. A flared end 7 of the socket, serving for subsequent entry of a connecting pipe, is formed by a conical, axially adjustably mounted, end portion 8 of the mandrel 4 which is also provided with blades 9 which trim the socket end during rotation thereof. The mandrel 4, which is mounted for rotation on a reciprocatory carriage 11, is provided with fluid passages 13 for the heating thereof, by water or steam during introduction into the pipe, which is also heated by external means 12, the passages 13 also serving for cooling of the pipe, e.g. by water, simultaneously with external cooling of the pipe by sprayed water or air from the means 12. The pipe 1 is supported during formation of the socket 3 between external clamping means 14 and an internal support 15 which is lockable in position to an extension 17 of the mandrel by means 18, which is automatically released upon rotation of the mandrel during axial introduction and retraction thereof from the pipe 1. The mandrel 4 is provided with a cylindrical extension 6 thereof, of smaller diameter than the pipe 1 and which serves as a guide during introduction of the mandrel. Where the pipe protuberances are helically directed, the mandrel is preferably rotated in the direction of the protuberances as viewed from the same end of the mandrel. |
