Patent attributes
Apparatus for the lifting of pipelines, includes a frame having two vertical side beams and a transverse top beam interposed between the vertical beams. Two concave and symmetrically disposed supporting members pivotally connect to the two vertical beams, respectively, and are configured to achieve a pipe supporting position without applying a radial inwardly directed force to the bottommost portion of the pipe when the frame is suitably lowered and the supporting members are suitably pivoted. A driving unit is disposed within, and fixedly attached to, each of the supporting members, for generating a linear downwardly directed force; a force transmitting element connected to a driving unit rod along which a corresponding driving unit housing is slidingly displaceable. A control unit independently controls each of the driving units; and at least one connector releasably connects the two supporting members to one another when the supporting members are in a pipe supporting position. The control unit is adapted to immobilize the force transmitting elements against a trench bed in a pre-lifting mode when a first force is generated by the driving units, and to lift each of the driving unit housings together with the corresponding supporting member with respect to the corresponding force transmitting element in a lifting mode when a suitable second force greater than the first force is generated by each of the driving units.
