Self-lifting drilling platform - has rack pinions coupled to vert. girder flexibly coupled to platform

摘要

The various pinions meshing with the same rack are coupled to a vertical girder accommodated in the platform structure. This girder is in turn coupled both at the upper and the lower end to the platform structure by means of elastic components. In the gear train to each of the pinions there can be two clutches, each with a freewheel. The freewheel of one clutch allows a platform support foot to descend freely in relation to the platform, and that of the other the platform to descend freely in relation to the foot. The freewheels are at points where the relative speeds between feet and platform caused by the swell give rise to acceptable freewheel speeds.