JPS6129312B

PURPOSE:To prevent occurrence of mistaken operations and to improve facilities of working by providing a reed switch facing with a permanent magnet installed in a cage and providing elevator shaft with a magnetism shielding plates by which the positioning may easily be adjusted. CONSTITUTION:The system is composed of an operation part 2 of a position detector comprising a permanent magnet installed in a cage 1 and a reed switch facing with the magnet, and a magnetism shielding plate 12 provided in an elevator shaft so as to locate between the permanent magnet and the reed switch facing with them. Side 13 of L-shaped member 11 is fixed to a long member 15 provided with purality of long holes and the long member 15 is fixed to a bracket 18, provided with plurality of threaded holes 16 and 17 and fixed to a guide rail 6 settled inside the elevator shaft with clips 7, with bolts 19 using the threaded holes 16, 17 and some long holes 14 of the long member 15 so as to locate the other side 12 of the L-shaped member 11, acts as the magnetic shielding plate, at a place corresponding to the middle of the permanent magnet of the operation part 2 and the reed switch. In this way, the mistaken operations are prevented and the facilities of working are improved.