| 主权项 |
1. A mobile cart comprising
a caster-support hub, a swivel caster mounted on the caster-support hub for swiveling movement relative to the caster-support hub about a vertical rotation axis from a centered position in a counterclockwise direction to a left-swivel position or from the centered position in a clockwise direction to a right-swivel position, and caster-controller means coupled to the caster-support hub for applying a yieldable clockwise torque to the swivel caster to urge the swivel caster to rotate about the vertical rotation axis in a clockwise direction to the centered position from the left-swivel position, and, alternatively, a yieldable counterclockwise torque to the swivel caster to urge the swivel caster to rotate in a counterclockwise direction to the centered position from the right-swivel position during movement of the mobile cart so that the swivel caster is maintained generally in the centered position while the mobile cart is in motion. |
