Abstract: The embodied hoisting mechanism has a hoisting cable, a hoisting-cable drive, a frame and a jib that can be topped. Hoisting-cable drive means form a path for the hoisting cable. A displaceable hoisting-cable guide is used with the hoisting cable so that the displacement of the displaceable hoisting-cable guide changes the length of the path. The displaceable hoisting-cable guide has an associated first hydraulic component with a first chamber that can be connected to a second hydraulic component with a second chamber of variable volume. A pressure source is coupled to the second hydraulic component in order to maintain a substantially constant hydraulic pressure in the second chamber. A pressure-limiting valve assembly, which is partially actuated by a topping-means loading sensor, is incorporated in the connection.

Abstract: The embodied hoisting mechanism has a hoisting cable, a hoisting-cable drive, a frame and a jib that can be topped. Hoisting-cable drive means form a path for the hoisting cable. A displaceable hoisting-cable guide is used with the hoisting cable so that the displacement of the displaceable hoisting-cable guide changes the length of the path. The displaceable hoisting-cable guide has an associated first hydraulic component with a first chamber that can be connected to a second hydraulic component with a second chamber of variable volume. A pressure source is coupled to the second hydraulic component in order to maintain a substantially constant hydraulic pressure in the second chamber. A pressure-limiting valve assembly, which is partially actuated by a topping-means loading sensor, is incorporated in the connection.