| 摘要 |
<p>A floor system allows for the transfer balls (20) to retract from or project above its floor surface. A lattice-like arrangement of reciprocally sliding structural channels (24) with a plurality of appropriately spaced elevating wedges (22) upon which lift wheels (ball bearings) (30) ascend and descend to swing the hinge plates (16) up and down, allows an equal number of transfer balls (20) to project or retract correspondingly through the floor level.</p> |
