| 摘要 |
<p>A lifting bar (28) has a cone-shaped end (30) for contact with a ball (26). The extension (10) comprises a basis body (14), a polygonal profile (20) provided on the basis body with a hole (24) in one side (18), a lifting bar extending into an axial bore (16), a ball in the hole in the side of the profile, and a setting bar (34) extending perpendicular to the lifting bar. Both bars are engaged with each other so that linear movement of the setting bar will change the position of the lifting bar and either lower the ball into its hole or raised the ball out of its hole.</p> |
