Patent ID: 6655539
Filing Date: 2003-12-02
Classification: B66C

Abstract:
A tower crane comprising sections hinged together with horizontal hinges, said tower crane comprising a load-bearing arm (50) made up of sections (23, 24, 25, 26) hinged together, and a tower comprising at least one pair of sections (20, 21) hinged together (12) and a third tower section (22) which is telescoped into one of said at least one pair of sections (20, 21); said tower being equipped with mechanisms enabling said pair of sections (20,21) to be set up vertically and taken down again to a horizontal position and said third tower section being adapted to be telescoped out of one of said pair of sections (20,21); said tower being hinged at its lower end (11) to a base structure (27) having a turntable (17), said tower having control means for the unfolding and re-folding of said crane by means of a series of flexible tie rods (30) running vertically along said tower and having above the load-bearing arm (50), tie rods that are hooked into the load-bearing arm (50) from above, said tie rods forming, together with parts of the base structure and the sections (20, 21 and 22) of the tower, an articulated quadrangle, with tie rods (31, 32, 33) which work with the aforesaid arm (50), which arm is characterized by the following features:a first primary section (23), hinged (13) at a first end of said first primary section to one side of the tower, and at a position on a second end of said first primary section (23) that is vertically higher than said first end, a hinge (14) which links said first primary section to a secondary section (24) that is adapted to allow the installation of a truck moving motor reducer, said secondary section (24) being hinged at a first end to said first primary section (23) and at a second end (15) hinged, to a second primary section (25) said second primary section (25) having a first end and a second end, said second primary section (25) being of uniform height, a third primary section (26), hinged at a first end (16) at its upper surface to the second end of said second primary section (25) actuating means (60, 62) for unfolding and re-folding the joints between the aforesaid first, second and third primary sections (23, 25, 26) means (68, 70, 32, 33) for providing structural integrity between said first and second primary sections (23, 25) when the load-bearing arm (50) is in the unfolded position.