| 摘要 |
<p>The device has a peripheral groove (21) constructed on a spindle in a hook base (1), and a coil spring (17) located between an upper end of the spindle and a bobbin case (5). The spring is compressed by the bobbin case when the bobbin case is set on top of the spindle. A connection element is provided on the spindle connected to the hook base. The peripheral groove is located in the connection element. A flange with crescent-shaped construction is constructed on the bobbin case, and protrudes into a central borehole of the bobbin case.</p> |
