| 摘要 |
<p>The cutting head is used with a long handle fitted with wheels on an axle. The lower end of the handle is parallel to the ground and has a bar in the end. This has two longitudinal diametrically opposite slots with a location boss in each slot near the end. The bar is inserted in slots in a socket on the head, the bosses locking in place. The other end of the bar, held in the handle, has serrations around its periphery, a spring loaded ratchet lever being used to select the operating position which is held by tightening a locking ring.</p> |
