closing device, in the event of a power outage, the large bell sealing directly to the top of a shaft furnace, particularly a blast furnace

摘要

975,565. Bell valves for shaft furnaces. MANNESMANN A.G. Jan. 30, 1961 [Jan. 29, 1960], No. 3502/61. Heading F4B. In apparatus for rapidly shutting the lower bell of a shaft furnace in the event of an electric power failure a rope 10 passes from a winch 26 over a pulley 28 on the end of a lever 24, the opposite end of which carries the bell 6, the free end of the rope being attached to a counterweight which is normally supported but is automatically released by appropriate electrical devices if the electric power fails. The counterweight consists of two parts 14 and 12, the former fitting inside the latter and being held in position by locking levers 16 and 16a which are maintained in this position by current from the power supply. The outer part 12 of the counterweight rests on a support 18 provided with a recess 20 into which the weight 14 may slide if the levers 16 and 16a are displaced. In normal operation the winch 26 raises or lowers the bell 6 by rocking the lever 24 about an axis 30 but if the electric supply to the winch fails the levers 16 and 16a are automatically displaced, causing the weight 14 to fall and raise the bell 6. The levers 16 and 16a may also be manually operated so that the bell can be closed at any desired time.