| 摘要 |
An appts. for regulating the working press. of a drill and compensating for the effect of swell during drilling operations at sea incorporates means of displacing one of the pulleys over which the cable carrying the drill passes, and thus increasing or decreasing the effective length of cable between its winch and the drill. The means consists of a piston fixed to the pulley and sliding in a cylinder connected to a source of fluid under press. and means of varying the press. in the cylinder. The cylinder may be mounted at the top of the drill structure or on the platform. The invention avoids the inconvenience of the drilling operations being stopped during the increasing or reducing of the weights on the drill, as in existing practice and eliminates the effects of the movement of the platform caused by the action of waves, tides and currents. |
