| 摘要 |
1506787 Pipe jointing apparatus PORTO & VALENTE INDUSTRIES PTY Ltd 15 June 1976 [23 June 1975] 24776/76 Heading F2G Pipes 12, 14, e.g. of concrete, cast iron or terra cotta, having a spigot and socket joint with a rolled in rubber seal 13 are forced together axially by sealing off a space around the joint and reducing the pressure in said space, e.g. by an ejector 20 or vacuum pump. Closure plates 16, 18 may seal the space within the pipes 12, 14, one 18 being connected to the ejector pump 20. Alternatively a pair of inflatable bags, Fig. 2, not shown, connected by a cable and air hose, may be inflated astride the joint, one having a through passage connected to the ejector pump. In a third embodiment (Figs. 4, 5, not shown) diaphragms, e.g. of flexible plastics, may form the closures. Such diaphragms may be successively positioned at every joint in a pipeline each having a closable passage therethrough, the diaphragms being successively sealed to minimize the volume of closed space needing to be evacuated; the diaphragms are then either successively or finally trimmed from the pipeline. |
