| 摘要 |
<p>The tool has a finger loop (7) of an operating handle (6) with a spherical inner face receiving a ring (13) having a spherical outer surface (14) making contact with the face. The ring has a central passage (15) to insert the fingers of a user. The ring has a length more than the thickness of the loop along an axis of the passage. The ring is free in rotation along the three axes by relative sliding in the loop in which the ring is inserted.</p> |
