Self-locking descender with disengageable handle
The descender comprises a handle and a cam that are movable between a securing position and a sliding position of the rope. The cam defines a first stop and a second pin. The handle has a first pin coming into contact with the first stop to form a first mechanical link and a second stop coming into contact with the second pin. Movement of the handle results in movement of the cam between the securing and sliding positions. In a threshold position of the handle, the first mechanical link is interrupted and the cam returns to the securing position. The second stop is movable with respect to the handle by means of a spring. When movement of the handle takes place, the second pin comes into contact with the second stop before the handle stresses a spring and reaches the threshold position.
1. A self-locking descender for a rope, comprising:
a first flange,
a handle having a first pin,
a cam movable with respect to the first flange between a first cam position designed to block the rope, and a second cam position designed to allow sliding of the rope, a first stop roatable on a second pin,
a second stop mounted on the handle, the second stop being mounted movable with respect to the handle,
a spring connected to the handle and to the second stop to resist movement of the second stop with respect to the handle,
the second pin mounted on the cam,
wherein the handle is mounted movable with respect to the first flange at least in a first direction of movement between a first handle position and a second handle position, the first pin escaping from the first stop when the handle is in a threshold position located between the first handle position and the second handle position, and
wherein the second pin contacts the second stop and stresses the spring when the handle is in a third position located between the first handle position and the threshold position, the second pin not stressing the spring when the handle is in the first handle position.
2. The self-locking descender according to claim 1 , wherein the second pin escapes from the second stop when the handle is in the threshold position.
3. The self-locking descender according to claim 1 , wherein a first ramp is fixed to the handle in movable manner, the first ramp defining the second stop and the spring connecting the first ramp with the handle.
4. The self-locking descender according to claim 1 , wherein a second ramp is fixed to the cam, the second ramp is mounted movable with respect to the cam and is configured to contact the first pin when the handle is in an intermediate position between the threshold position and the first handle position.
5. The self-locking descender according to claim 4 , wherein the first pin is formed by a rod movable in rotation, the second ramp forcing rotation of the rod to interrupt a first mechanical link and to interrupt a mechanical connection between the second pin and second stop.
6. A method for using the self-locking descender of claim 1 comprising:
providing the rope and the self-locking descender, the self-locking descender comprising the first flange, the handle fitted movable with respect to the first flange in the first direction of movement, the cam designed to block the rope and being movable between the first cam position securing the rope and the second cam position allowing sliding of the rope, the handle being mechanically connected to the cam by the first pin,
moving the handle in a first movement in the first direction of movement so that the handle successively defines the first handle position of the rope where the cam blocks the rope, the second handle position where the cam allows sliding of the rope and the threshold position where the first mechanical connection between the handle and the cam is interrupted, the cam returning to the securing position,
wherein during the first movement, the handle defines an additional mechanical connection which stresses the spring before reaching the threshold position.
7. The method according to claim 6 , wherein a second pin is fitted salient from the cam and the ramp is fixed to the handle, the ramp defining the second stop for the second pin, the second stop being movable with respect to the handle by means of the spring moving the second stop to a first position, and wherein the second pin and second stop are arranged in such a way that, when the first movement of the handle takes place in the first direction of movement, the second pin comes into contact with the second stop before the handle stresses the spring and reaches the threshold position.
8. The method according to claim 7 , wherein a second ramp is fixed to the cam, the second ramp being fitted movable with respect to the cam and being configured so as to come into contact with the first pin when movement of the handle takes place in the direction of the threshold position.
9. The method according to claim 8 , wherein the first pin is swivel-mounted and movement of the handle to the first threshold position forces swivelling of the first pin by means of the second ramp.