| 摘要 |
A wheel undercarriage for carriages has at least three wheel units 29-32, which are rotatable about their respective steering axle 33-36. The steering axles extend perpendicular to the wheel axle 45-48 of the wheel units and, viewed in a plane parallel with the wheel axles, are widely spaced and extend through this plane at points at least one of which lies at a distance from a straight line running through two or more of the other points. The wheel undercarriage has a drive mechanism 37-43 for rotation of the steering axles 33-36 and adjustment thereof, and hence of the wheel axles 45-48 of the wheel units mounted on the said steering axles, into four different adjustment positions, namely firstly a first position in which the wheel axles 45-48 of all the wheel units are parallel with one another and extend in a first direction, secondly a second position in which the wheel axles of all the wheel units are parallel with one another and extend in a second direction perpendicular to the said first direction, thirdly a third position in which extensions of the wheel axles of all the wheel units mutually intersect at a common point of intersection 44, and fourthly a fourth position in which the wheel axles deviate from parallelism with one another and in which at least one wheel axle is placed in a direction other than towards the said point of intersection 44. This configuration enables the wheel undercarriage to be displaced in two mutually perpendicular directions (the first and second positions), rotated or turned (the third position) and parked (the fourth position). <IMAGE> |
