A brake for a hoisting apparatus

摘要

The present invention relates to a brake (4) for a hoisting apparatus (1). The hoisting apparatus comprises a hoisting line, a drum for the hoisting line, a hoisting motor and a brake system (4) for braking of the hoisting cable, the brake system (4) consisting of a hydraulic brake (8) and a mechanical brake (9). The invention consists of the fact that the mechanical (8) and the hydraulic brake (9) are connected to a common transmission (30) which is driven by the drum when this rotate freely, and the fact that the mechanical (8) and the hydraulic brake (9) are controlled by a common control means (5) for controlling the distribution of braking power between the two brakes. The control system distributes the braking power automatically between the brake systems. The transmission (30) can also be connected to an autodriller (10) for controlling the weight on the bit. <IMAGE>