| 摘要 |
1535523 Ramming equipment KOEHRING GmbH 17 Nov 1975 [16 Nov 1974 (2) 30 Aug 1975] 47289/75 Heading B3H Ramming equipment, e.g. a pile driver, comprises a ram casing 2, a ram 25 reciprocable in the casing, a gas filled working chamber 24, a ram cylinder 30 associated with the casing 2 or with the ram and containing a piston operable by a pressure medium and linked to the ram, and control valve means which connect the cylinder through pipe or duct means to a supply of the pressure medium. A pile driver for driving a submerged tubular pile 29 is provided with a cap 27 which rests on the pile and is fitted with an annular seal 26. The ram 25 impacts the cap 27 and as it reciprocates gas inside the chamber 24 is displaced from one side of the ram to the other via ports (34) and a spill duct (33), Fig. 8 (not shown). Pressure fluid is supplied to the ram cylinder 30 by means of hydraulic pumps 6 actuated by motors 5, the pumps supplying fluid directly into a reservoir 7. A flexible element in the wall of the reservoir varies its capacity proportionately to external pressure when the pile driver is used under water. Pressure fluid is supplied continuously under the piston 31 in the ram cylinder while valve means 10 provide an intermittent feed to the upper face of the piston. The pumps and motors are mounted in a driving unit 1, which is slidably mounted on the cylinder 30 and a shaft 38 by means of shock absorbing elements 4. A jacket 3 provides buoyancy and the unit 1 is secured to the casing 2 by tension elements 11 and spring buffers 12. The bottom of the unit 1 is fitted with hydraulic cylinders 13 which co-operate with accumulators 15 and act as shock absorbers when the equipment is working above water. The degree of shock absorption is adjusted by varying the pressure in the accumulator. In an alternative construction, the gas already in the casing is compressed by admitting water into the casing as the equipment is submerged and it is fed to the buoyancy jacket and working chamber so as to equalize the gas pressure in them with that of the surrounding water. The flow of water into the casing may be controlled by valves, Fig 7 (not shown). An impact plate (28), Fig. 3 (not shown), may be provided between the ram (25) and cap (27). In a further construction, Fig. 8 (not shown), compressed gas is supplied from an external source to form a cushion (69) under the cap (27) and into the working chamber (24). The cap (27) is provided with a bore which connects the chamber (24) with the cushion (69), the bore containing throttling constrictions (97) with storage spaces (96) so that the fluctuations of gas pressure as the ram operates do not affect the cushion.
|
