| 摘要 |
A welding plant for thermoplastics pipes comprises clamps to hold the two pipe ends and a thrust mechanism to push one pipe end against the other. Each clamp consists of an upper strap and lower saddle, with resilient seating members forming a ring around the pipe. In the annulus between this ring and the strap-saddle combination, a tyre is mounted, and this can be rotated around the axis of the clamp, centering the pipe as it is clamped. Pref., two roller bearing units are used, one between the ring and the tyre, the other between the tyre and the strap-saddle combination. On its inner periphery, the tyre has V-shaped depressions, so that as the tyre is rotated, these depressions force the inner rollers inwards, thus clamping and centering the pipe. |
