Automatic alarming device for falling of optical-fiber preform heavy head

The utility model relates to an automatic alarming device for falling of an optical-fiber preform heavy head, which is characterized in that: a signal transmitter and a signal receiver which is connected with an alarming device are respectively arranged on two opposite positions at two sides of a passage, and an optical fiber preform heavy head below a fiber drawing furnace drops down along the passage. A heavy head is formed and falls slowly after an optical fiber preform is heated by the fiber drawing furnace for a given time, and the heavy head drops off the wire drawing furnace to between the signal transmitter and the signal receiver, so a signal transmitted by the signal transmitter is interfered, the signal cannot be normally received by the signal receiver, then the signal receiver can send out an order to an alarming device, and the alarming device issues an alarm. Due to adoption of the automatic alarming device, the operator is unnecessary to stay on the spot during the time from the heating of the