GB255779A - Improvements in blast furnace bell operating mechanism - Google Patents

Abstract

255,779. Kling, F. E., and Krause, R. C April 9, 1926. Charging.-In a furnace having upper and lower charging hoppers 9, 7 closed by balls 10, 6, the latter are operated separately by mechanisms B, C each comprising a member supported on and movable, relatively to a carriage 30 which runs upon an inclined track 27, 28. Each carriage 30 is formed with a centrally arranged guideway 31 in which is slidably mounted a rack member 32 adapted to be operated by a pinion 34 which is driven through spur and pinion gearing from an electric motor 33 mounted on the carriage. A roller 37 supports the front part of the rack 32 which is forked at its forward end to form bearings for a shaft 57 which carries wheels 54, 55 running on a track 53, and forms a pivot for a link 58. Fig. 4 shows the arrrangement for operating the upper bell 10, a screwed rod 59 being adjustably mounted in the link 58 and carrying a sheave 61; a cable 62 is secured at one end to the sheave 61 and at the other to a sheave 63 on the operating lever 21 from which the bell 10 is suspended. In the case of the lower bell 6 there are adjustably secured to the link 58 two sheaves 67, 68, Fig. 3, to which are secured the ends of a cable 69 passing round a sheave 71 on the belloperating lever 22. At the lower end of the track 27, 28 is arranged a stop 45 adapted to be engaged by a spring buffer 46, 47 on the carriage 30 and through which extends a rod 48 secured to the carriage and embraced by springs 49 held in position by a washer 50 and nut 51. To lower either of the bells, the motor 33 is operated to rotate the pinion 34 in a clockwise direction and consequently to permit the carriage 30 to travel downwardly until the springs 47 are sufficiently compressed to balance the downward force; when the carriage comes to rest the rack 32 moves upwardy to lower the bell, a limit switch being operated to shut off the motor when the rack reaches its highest position. To close either bell the motor is reversed and the operation is continued for a short interval after the bell is seated to cause an upward movement, which is accelerated by the springs 47 of the carriage 30 to a position where its weight is taken entirelv bv the cable 62 or 69. A second limit switch for shutting off the motor is adapted to be operated by this upward movement of the carriage 30. A modification is described in which the rack 32 is replaced by a screwed rod advanced and retracted by a nut secured against longitudinal movement in the carriage and rotated through gearing from the motor 33.