| 摘要 |
The invention relates to a braking apparatus for braking the rotating part (1) of a hoisting machine. The braking apparatus comprises one or more brakes (3, 4), which contain altogether at least one movable brake shoe (5, 6), spring elements (7, 8) for activating the brake by moving the brake shoe (5, 6) forward, at least two electromagnets (9, 10), which, when magnetized by a magnetizing current, apply a force of attraction to bodies conducting magnetic flux. The electromagnets are fitted to release the brake (3, 4) by pulling the aforesaid at least one brake shoe (5, 6) back¬ wards by resisting the aforesaid spring elements (7, 8). The brake (3, 4) is fitted to be activated by reducing the magnetizing current of the electromagnet (9, 10). The braking apparatus comprises a power supply circuit (1 1) for the electromagnets, which contains controllable power supply interrupting devices (12, 13, 14, 15). The electro¬ magnets (9, 10) are connected to the said power supply circuit (11) in such a way that the supply of magnetizing current to each electromagnet can be interrupted by means of at least two different interrupting devices (12, 13, 14, 15). |
