| 摘要 |
<p>The device has a receiving structure (2) that supports a thrust bearing (1). The thrust bearing is movable between an inactive position that allows the positioning and removal of an attachment head covering a ball of reception, and an active position in which the bearing is extended above the ball. A U-shaped bolt solidarizing the device on the hook in active and inactive positions and surrounding neck of the receiving ball. The bearing in the active position prevents the unhooking of the attachment head on the receiving ball.</p> |
