Patent ID: 7093823

Claim:
A lifting unit, comprising: a frame; a motorized winch; at least one first tackle; at least one second tackle, said first tackle being interposed between said second tackle and said winch, said first and second tackles and winch being supported at said frame; two blocks, provided at each of said first and second tackles, a fixed one and a movable one; at least one pulley, provided at each one of said blocks; a flexible element, having a first end connected to said winch and being wound around said pulleys so as to form at least one initial loop around said first tackle, an outgoing portion from said first tackle to said second tackle, at least one intermediate loop around said second tackle, a return portion from said second tackle to said first tackle, and at least one end loop around said first tackle, a second end of said flexible element being connected to said frame; and locking means which act at said flexible element along said return portion for temporarily locking sliding of said flexible element.