PURPOSE: To prevent the occurrence of burning of a solenoid owing to the abnormal stop of a pallet by providing a current limiting element which limits a current flowing through a solenoid after a stopper is moved aside from the drop preventing position for a pallet.

CONSTITUTION: A limit switch 11 for electromagnetic type drop preventing devices A-D has a normally-opening contact 11a and a normally-closed contact 11b. The normally-closed contact 11b is incorporated in a solenoid limit circuit A and connected to a current limit resistor 20 in parallel to the normally-closed contact 11b. The solenoid 10 is connected in series to a parallel circuit of a current limit resistor 20 and the normally-closed contact 11b. A solenoid limit circuit A is connected to a power source 32 through a normally-closed contact 16b of a lower limit limit switch 16 and a contact 23a of an elevation selecting switch 23. When the pallet is raised to an upper state stop position, a normally- closed contact 17b is brought into an OFF-state, and a motor 34 is stopped by means of a motor drive control circuit 33. When the pallet is lowered to a lower-stage stop position, the normally-closed contact 16b is brought into an OFF-state and the motor drive control circuit 34 is brought into a stop.