Patent ID: 6536541
Filing Date: 2003-03-25
Classification: E02D,E21B

Abstract:
Boring unit (1) for pile foundations comprising a platform (3) facing a mouth of a hole, a mast (5) which is supported by the platform (3), a rotary table (6) slidingly mounted along the mast (5), and an excavation element which is connected to the table (6) and which presents a boring tool (8) at its lower end; the unit (1) comprising a handling device (11) of the excavation element (7) and further auxiliary excavation elements (19, 20) which in turn comprise a head (12) which is mounted at a top end of the mast (5), and which is provided with a hoist (13) that is configured to be connected to the excavation element (7), and which is also provided with a central cable (14) which is configured for moving the excavation element (7) alternatively to the hoist (13) between a lowered working position, in which the excavation element (7) is arranged inside the hole, and a raised working position, in which the excavation element (7) is arranged substantially outside the hole; the handling device (11) also comprising a drive unit (40) which is configured to cooperate with the hoist (13) in order to rapidly move the auxiliary excavation elements (19, 20), and wherein the hoist (13) comprises a support frame (15) which is mounted on top end of the mast (5), a first and a second pair of pulleys (28) which are mounted side by side in relation to each other on the frame (15) in order to rotate around a respective horizontal rotation axis, a swinging beam (21) which is centrally hinged onto the mast (5) inside the frame (15) between the first and second pair of pulleys (28) and which is provided with two revolving blocks configured to rotate about a common horizontal rotation axis which is transverse to the rotation axis of a relevant pulley (24) of the beam (21).