| 摘要 |
1,211,066. Valves. S. E. COBLITZ. 13 March, 1969 [17 Oct., 1968], No. 13406/69. Heading F2V. Shut-off tool for resiliently deformable plastic gas or water pipes, e.g. of polyethylene, situated below ground level, comprises opposed die members 42, 76 adapted to receive and squeeze the pipe between them, means for urging the die members together, and resilient means for axially and laterally aligning the tool on the pipe. The upper die block 42 is slidable on pillars 38, 40 mounted in a head 34. This head is fixed to a hollow stem 22 carrying a handle 26. An operating rod 62 extending through the stem is in screw-threaded engagement with the head 34 and bears on pressure plate 46 on the upper block. To engage the tool, the lower block is lifted slightly, through a rod 90 having a handle 100, and swung out of the way before re-engagement. A pair of crossed springs 52 at the front and rear of the upper block are effective to laterally centre and align the tool on the pipe by forming a yieldable cradle. |
