| 摘要 |
<p>A device (1) which includes an elongate body (2) with a movable mass (3) arranged for sliding movement within the body (2), the element (4) being arranged to decelerate toward an end of the body (2) in order to impart forward movement thereto, via momentum transfer, and being arranged to accelerate away from said end in order to further drive the body (2) forward, again using momentum transfer.</p> |
