| 摘要 |
<p>An oar or paddle comprising a shaft having two parallel grooves of circular cross-section extending throughout its length, each groove pivotally supporting a blade. The grooves have a peripheral extent which permits the blades to pivot between a position in which they are parallel, at a further position in which they project in opposite directions in a common plane. The blades are located axially of the grooves by means of retainer which are mounted in the grooves at engage well opposite ends of the portion of the blades disposal within the groove.</p> |
