摘要 |
<p>A device adapted for use as a positively driven steering member in a conveying apparatus, having a wheel with a spherically curved inner surface, a hub with a spherically curved outer surface which fits inside of the wheel, and a coupling which secures the wheel to the hub, permitting the axis of the wheel to be rotated relative to the axis of the hub in any direction while restraining relative motion between the wheel and hub about the axis of the hub. This arrangement provides that, when the hub is driven by a shaft passing through its axis, it drives the wheel, regardless of the angle between the hub and wheel.</p> |