| 摘要 |
<p>A four wheel drive toy (10) includes a drive mechanism (50) and two pairs of elongated movable track portions (20a, 20b) mounted on a frame (18), each pair of track portions including a follower gear (24) driven through an independent gear train from the drive mechanism. An interior surface of each track portion includes an oval endless rack gear (30) engaged by the gear followers. The orbit of the gear follower around the rack gear is made visible from the exterior of the vehicle by using flanges (34, 38) attached to either side of the follower gear to retain the follower gear within the interior of the track portion. The track portion pivots about the axis of the follower gear when the follower gear reaches the arcuate region (33) of the oval rack gear.</p> |
