| 摘要 |
<p>A convertible dolly assembly having an elevatable fifth wheel and a specially locked, telescopically mounted drawbar. The dolly may be employed as a tandem axle on a tractor by lowering the fifth wheel, retracting the drawbar and fitting the drawbar and its supporting structure into a sleeve having locking means therein positioned at the rear of the tractor. Special cooperating locking means on the drawbar and the tractor include a rotatably engageable lock coupling on the end of the drawbar and a cooperable lock coupling in a sleeve mount on the tractor. For use as a towing dolly to pull a second trailer, the drawbar is rotated 90 DEG thereby unlocking it and allowing it to be extended. Once extended, it is again rotated 90 DEG to lock it in extended position. The fifth wheel can be locked in its raised position by a pair of special locking and support keepers slidably mounted on the frame.</p> |
