| 摘要 |
1. Toothed unlocking device for a safety joint to articulate a mobile piece (1) to a reference piece (2) by means of a toothing comprising inclined teeth arranged on the mobile piece (1) and on the reference piece (2) around the articulation axis (3) opposite to each other, the mobile piece (1) being mounted on the axis self-supporting so that its center of gravity is offset relating to said axis, and said device having a retension means actuating the mobile piece (1) following the axis and having a control member (4) and a cam, characterized in that the cam has four adjacent cam surfaces (41, 42, 43, 44), namely a first surface (41) of a total engagement of the toothing, a second surface (42) for a partial disengagement, a third protruding surface (43) permitting partial reengagement and a fourth surface (44) for total disengagement of the toothing, and that the inclination (alpha) of the teeth of the toothing (11, 21) is so that the axial resultant (R) on the teeth of the toothing (11, 21) of the couple resulting from the self-supporting mass of the mobile piece (1) in the position of the partial disengagement, determined by the second cam surface (42) is in the opposite sense greater than the resultant of the force which can be applied manually to the control member (4) normally. |
