| 摘要 |
<p>A reclosable mast (2) comprised in a drilling rig (1). Said mast (2) comprises:
—� two opposed latticed structures (22), which are constrained at one end to the base structure (10) placed in the drilling site "P" and at the opposite end to each other, thus defining the side faces (2b) of the mast (2);
—� a plurality of U-shaped structures, each comprising a rear bar (40), adapted to get compressed when closing the mast (2), and two side shoulders (41) parallel to each other and perpendicular to said bar (40), with which they are associated. Said U-shaped structures are arranged at preset intervals between the two latticed structures (22), so that said rear bars define the rear face or back (2a) of the mast (2). Said mast (2) comprises a plurality of diagonal members (3), located on the rear face (2a) of the mast and constrained, when in use, between two superimposed U-shaped structures, said plurality of diagonal members (3) being adapted to:
—� splitting into at least two portions
—� reducing their longitudinal extension,
in order to allow reducing the dimension.</p> |
