| 摘要 |
<p>In an elevator hoist, a rotating body is braked by a braking device. The braking device comprises a braking body which can be shifted in directions in which the braking body comes into contact with or gets away from the rotating body, a movable body which is shifted together with the braking body, an urging body which urges the movable body in the direction in which the braking body comes into contact with the rotating body, and an electromagnetic magnet which comprises a circular electromagnetic coil and a field on which the electromagnetic coil is provided and which, upon the supply of power to the electromagnetic coil, allows the movable body to be shifted in the direction in which the braking body gets away from the rotating body. The field has an inner pole portion passing in the inner side of the electromagnetic coil and an outer pole portion which is continuous with the inner pole portion and which is arranged on the exterior side of the electromagnetic coil. An inner pole opposing surface and an outer pole opposing surface which each are opposed to the movable body are provided on the inner pole portion and the outer pole portion. The magnetic flux content which indicates magnetic saturation of the outer pole opposing surface is smaller than that of the inner pole opposing surface. A leakage member for allowing a magnetic flux to pass between the movable body and the outer pole portion avoiding the outer pole opposing surface is opposed to the movable body and the field.</p> |
