| 摘要 |
1537386 Boreholes &c COMPAGNIE INTERNATIONALE DES PIEUX ARMES FRANKIGNOUL 11 June 1976 [12 June 1975] 24234/76 Heading E1F A borehole closure device 11 to enable grouting liquid to be injected through the device for stabilising the ground, is adapted to be secured at 15 to one end of a main injection pipe and comprises a straight pipe 16 through which liquid to be injected may flow, a single-acting ram-like annular actuator 17 including a movable part 21 which is slidable in coaxial relationship along the outer surface 22 of the pipe 16, a separate duct 31 to supply the actuator 17 with pressurised fluid, and at least one transversely expandable annular sealing packing member e.g. 18 mounted coaxially about and along the outer surface 22 between the movable part 21 and a stationary abutment 33 secured to the pipe 16. Preferably several packing members 18, 19, 20 are provided, each being resiliently deformable, comprised of e.g. rubber, and being separated from each other by washers 34, 35. In their rest condition (Fig. 2, not shown), the packing members 18, 19, 20 preferably have the same diameter as the washers 34, 35 and the movable part 2]. As shown, the piston 23 of the actuator 17 is secured to the pipe 16 and has a duct 30 to provide communication between the working chamber 26 of the actuator 17 and the duct 31 which is connected at the ground surface to a pressure source. |
