| 摘要 |
<p>The hoist mechanism of the vertically movable door has a reel (32) fitted around an axis (30), which is rotated by means of a motor, on which reel hoist wire (28) is stored. The hoist mechanism further contains a slack switch for halting the motor when the tension of the hoist wire decreases. The slack switch is arranged in connection with the reel, and it has a rod (52), which is fitted to rest itself against the hoist wire unravelling from the reel and to alter its line of travel. The hoist wire holds the slack switch in the first position as long as its tension exceeds a predetermined threshold value, whereby the motor functions normally. When the tension of the hoist wire falls below the threshold value, for example as a result of the hoist wire breaking, the slack switch moves into the second position, which switches off the function of the motor. The slack switch comprises a first and a second support arm (50a, 50b), which are attached at their first end in a pivoted manner (54) to the structures of the vertically movable door. The rod resting itself against the hoist wire is attached at its ends to the ends of the support arms, and the hoist wire is fitted to travel between the support arms over the rod. The slack switch is arranged to move from the first position into the second position by rotating around the pivot pin (54). The rotation of the slack switch occurs by means of gravity, when the potential energy stored in the slack switch is released. The hoist mechanism according to the invention can be used in vertically movable doors of fabric, which fold upwards.</p> |
