| 摘要 |
This hand truck is designed to enable heavy cargo to be easily transported up or down stairs. The truck utilizes a pair of rotatable large wheels with radially and equally spaced apart lobes or projections to engage with steps, so as to prevent an operator from struggling when ascending or descending the steps with the cargo. These large wheels are electric motor driven and fixed in position on the frame of the hand truck, and a pair of small wheels are provided for flat surface travel on a flat surface by a hand crank mechanism attached to the frame of the truck. In one embodiment a crank mechanism is provided with a pair of worm shafts, guide rails, bevel gears, and other components, for lowering and elevating the small wheels.
|
