| 摘要 |
<p>1,078,607. Offshore platforms. WERF GUSTO V'H FIRMA A.F. SMULDERS N.V. Jan. 3, 1966 [Jan. 8, 1965], No. 95/66. Heading E1H. An offshore drilling platform consists of a pontoon 1 and a number of columns or legs 3 which can be displaced vertically through openings 2 relative to the pontoon 1 by doubleacting hydraulic jacks 7 which engage recesses 4 of the columns 3 by locking members 5, while further locking members 9 lock the columns 3 relative to the pontoon. The liquid chambers 12 and 13 on either side of the piston 10 of each of the hydraulic jacks are interconnected via the conduit (23) which includes adjustable shut-off valves (24), (25), Fig. 3 (not shown) and with which an expansion tank (30) is connected. The conduit (23) incorporates non-return valves (26), (27) parallel to the shutoff valves (24), (25) in such a way that, as the pontoon 1 moves upwards relative to the columns 3 in each jack the liquid can freely flow from chamber 13, then becoming smaller, towards chamber 12 which is growing larger, but not the other way round. By means of the shut-off valves it is possible to damp the movement of the pontoon due to surge of the sea as the columns or legs are lowered rapidly to the sea-bed, the expansion tank (30) being required in connection with the difference in volume on either side of the pistons 10 in the jacks. During and after the lowering of the legs their bumping on the sea-bed is avoided. The duplication of the shut-off valves (24), (25) and the opposite directions of the non-return valves (26), (27) enable use to be made of the surge of the sea in clearing the legs from the seabed.</p> |
