| 摘要 |
<p>A track (17) and a vehicle to operate thereon, the track (17) comprising two laterally spaced apart sets of running faces (18, 20) each of which having an upper running face (18) and a lower running face (20), the vehicle having at least one axle assembly (12) with at least a first set of two wheels (6) journalled thereon and engaged with the respective upper running faces (18) and a second set of two wheels (19) journalled thereon and adapted to engage with the respective lower running faces (20), characterised in that the second set of wheels (19) are forced into running engagement with the respective lower running faces (20) by at least one actuating mechanism (21, 24) which varies the force of engagement by means of a sensed signal indicating loss of adhesion or imminent loss of adhesion of the first set of wheels (6) with respect to the upper running faces (18). Also disclosed is an arrangement wherein the first set of wheels (6) are inwardly inclined and mounted on a self steering bogie (7) having a set of freely rotating flanged steering wheels supported from the axle assembly (12) and engaging the upper running faces (20).</p> |
