Abstract: Jamming devices for rope comprise a casing (2) consisting of two pallely, one above the other situated flanges (3, 4) between which are perpendicularly mounted the first and the second pulleys (12, 13) as well as a jamming cleat (14). The second pivoting pulley (13) is fastened to the lever (11); the latter is pivoted eccentrically to centre of the pivoting pulley (13) and can be swayed to and fro within the limits determined by the design. The second pivoting pulley (13) is in functional relationship with the fixed pulley (15) and so the rope (10) can be wedged between the fixed pulley (15) and the second pivoting pulley (13) in the first jamming position. The lever (11) can be by means of the arc-adjuster (16) moved away from the fixed pulley (15). In functional relationship with the jamming cleat (14) is the press-boss (17); between the latter and the jamming cleat (14) the rope (10) can be wedged in the second jamming position.