摘要 |
<p>A trailer (1) having a frame (2) defining a loading bed (3); and a number of rubber-tyred steering carriages (4) connected to the frame (2). Each carriage (4) has a respective axle (5); and a respective variable-length, vertical column (27) connected to the axle (5) and hinged to the frame (2) to rotate about and translate along a fixed hinge axis (28). Each axle (5) has a beam (6); and two hubs (8) which are connected in rotary manner to opposite end portions of the beam (6) and on opposite sides of the vertical column (27), are fitted with respective rubber-tyred wheels (11), and are each powered by a respective motor (18) controlled independently of the other motor (18) to move the carriage (4) forward and/or steer the axle (5) about the fixed hinge axis (28).</p> |