US2341772A - Bell hoist - Google Patents

Description

Feb. 15, 1944. A. E. HANDY ETAL 2,341,772

BELL HOIST Filed April 14, 1945 2 Sheets-Sheet 1 FIQI V V (3m INVENTORS BY 1 y If!!! ATTORNEY Feb. 15, 1944. A; E. HANDY ET Al.

BELL' HOIST Filed April 14, 1945 2 Sheets-Sheet 2 INVENTORS Patented Feb. 15, 1944 BELL HOIST Arthur Edward Handy, Lynbrook, N. Y., and Valdemar Bertelsen, Bogota, N. .L, assig'nors to Otis Elevator Company, New York, N. Y.,

a corporation of New Jersey Application April 14, 1943, Serial N0. 483,074

1 Claim.

The invention relates to blast furnace bell hoists.

In charging a blast furnace, it is common practice to carry the stock in skips to the top of the furnace where it is dumped onto a small bell. The small bell is then opened to dump the stock onto a large bell and reclosed. This cycle of operation is repeated until a certain number of loads have been dumped onto the large bell whereupon after the small bell has been reclosed the large bell is opened to dump the charge into the furnace. The large bell is then closed and the operation is repeated. This gives the desired charge to the furnace and maintains an effective seal at the top. The bells are biased to closed positions by counterweights; Occasionally an explosion takes place in the compartment between the two bells resulting in the forced opening of the large bell. After the pressure is relieved the large bell is reclosed by its counterweight and in case the bell has been opened very wide the bell may slam in closing.

The object of the invention is to provide bell operating mechanism in which slamming of the bell in closing is obviated.

In carrying out the invention an arrangement is provided which does not affect the normal operation of the large bell but which, in the event of abnormal operation of the bell such as would take place in the event of an explosion between bells, causes the large bell to close at a sufiiciently low speed to prevent damage to the apparatus when the bell seats under the action of the counterweight.

Features and advantages of the invention will become apparent from the following description and appended claim.

n the drawings:

Figure l is a simplified schematic representation of a blast furnace installation embodying the invention;

Figure 2 is an enlarged detail-in side elevation and with parts broken away of the counterweight and retarding mechanism for the large bell; and

Figure 3 is a view taken along the line 33 of Figure 2.

For a general understanding of the invention, reference may be had to Figure 1. The blast furnace II is provided at the top with a hopper [2 for receiving the stock from the skip buckets. Upon the stock being dumped into the hopper it falls on the small bell 13. The small bell in turn dumps the stock on the. large bell l4. When a specified number of loads have been dumped onto the. large. bell,. the. large bell dumps the charge into the furnace. The small bell is connected by a hollow rod E6 to one end of lever I1. At its opposite end lever I1 is connected by roping 8 to 'a counterweight 29, passing over idler pulley 2|. This counterweight is of sulficient mass to counterbalance the weight of the bell and the rod plus the weight of the load of stock resting on the bell. The counterweight is guided in its upward and downward movement on guides 22. Similarly, large bell I4 is connected to a lever 23 by a rod 24 which extends through hollow rod 16. Lever 23 is likewise connected by roping 25 to a counterweight 26, passing over idler pulley 21. The counterweight counterbalances the weight of the bell and the rod as well as the weight of stock resting on the bell. The counterweight is guided in its upward and downward movement by guides 28.

The hoisting machine for the bells comprises two drums 3B and 3t which are loosely mounted on a shaft 32 supported by bearing pedestals mounted on base 33. Roping 34 is connected at one end to drum 3i and extends upwardly over idler pulleys 35 and 36 and thence downwardly where its otherend is connected to small bell counterweight 20. Roping 31 is connected at one end to drum 30 and extends upwardly over idler pulleys 38 and 40 and thence downwardly Where its other end is connected to large bell counterweight 2'0. Rotation of drum 3| from the neutral position shown causes roping 34 to lift counterweight 20, thereby opening small bell I3. Rotation of drum 30 from neutral position causes roping 31 to lift counterweight 26, thereby opening large bell [4.

A drivinggear 42 is keyed t6 shaft 32. A lug i3 is provided on each side of the gear. A lug 44 To close the small bell, the direction of rotation of gear 42 is reversed to allow drum 3| to return .to neutral under the influence of counterweight 20. A similar lug 45 is arranged on drum 30 in the path of movement of the other lug 43 on gear 42 so as to be engaged thereby when gear 42 is rotated from neutral in the opposite direction.

Continued rotative movement of the gear after lug 45 is engaged causes rotation of drum 30 to open'the large bell. In closing the large bell,

the direction of rotation of gear 42 is reversed to allow drum 30 to return to neutral under the infiuence of counterweight 26. Driving gear 42 is driven by a pinion 46 on shaft 41 supported at its outer end by an additional bearing pedestal mounted on base 33. The other end of shaft 4! is driven by a worm gear arranged in casing 48 mounted on base 33. The driving worm for the worm gear is driven by an electric motor 50 also mounted on base 33. An electro-mechanical brake is provided for bringing the rotating members rapidly to rest when the motor is deenergized.

To prevent the slamming of the large bell in closing in the event it has been blown open by an explosion in the chamber between the bells, the counterweight 26 for the large bell is provided with a retarder designated as a whole as 50. Referring to Figures 2 and 3, the large bell counterweight comprises a plurality of weights 6| illustrated as held together by means of clevis bolts 62 extending through the weights. A plate 83 is arranged between the clevis ends of the bolts and the weights while another plate 64 is arranged between the nuts 65 on the lower ends of the bolts and the weights. The clevis end of the bolts are utilized for securing the roping 25 and 31 to the counterweight. Channels 66 are secured to the weights, one on each side thereof, and support guide shoes 6'? at the upper and lower ends. The guides 28 for the guide shoes are secured at their bottoms as by angles 68 to a base 10. I

The retarder 59 comprises a plunger H which is secured to the bottom of the counterweight as by having the plate 64 welded to the top of the plunger. This plunger extends downwardly into a cylinder 12. The cylinder has a flange 13 secured thereto as by welding which in turn is mounted on base 70 to form a support for the cylinder. The upper end of the cylinder extends into an oil reservoir M. This reservoir is secured to the cylinder as by welding at to form a leak-proof joint. This reservoir is also supported on a frame 16 secured to the guide rails 28. An opening 1'! is provided in top of the reservoir through which the plunger H extends. The upper end of the cylinder is provided with a packing gland T3 to prevent the leakage of oil out of the top of the cylinder. This packing gland is wholly within the reservoir so that should any oil leak out of the top of the cylinder it is returned to the reservoir. A bafile 80 extends downwardly from the top of the reservoir to the top of the packing gland to prevent oil being splashed out through the opening 11 around the plunger.

The bottom of the cylinder is connected to the bottom of the oil reservoir. This is effected by a pipe 8! secured to the bottom of the reservoir and connected at its lower end by means of an elbow 82 to a valve chamber 83. The valve chamber 83 has an opening at the top thereof connecting with an :opening 84 in the base 85 of the cylinder. the valve chamber and biased by gravity to engage valve seat 81 and thus close the connection from the valve chamber to pipe 8|. This valve is opened, however, upon raising of the plunger H within the cylinder, to permit the passage of oil from the reservoir into the bottom of the cylinder. The side of the cylinder at a point just below reservoir 14 is also connected to the bottom of the reservoir. This is effected by a .pipe 90 .securedtothe bottom of the reser- A hinged valve 66 is arranged within voir and. connected at its lower end by means of an elbow 9| to a valve chamber 92. The left hand end of the valve chamber is connected as by a short pipe 93 to the side of the cylinder. A regulating valve 94 illustrated as of the globe valve type is provided in valve chamber 92 to regulate the amount of oil exchange which can take place between the reservoir and the side of the cylinder. This valve is set to restrict the flow of oil from the cylinder back into the reservoir during downward movement of the counterweight to such extent as to prevent this movement taking place above a certain speed.

During normal operation of the furnace the retarder does not afiect the speed of either the opening or the closing of the large bell. Upon opening of the large bell, the plunger moves upwardly in the cylinder as the counterweight is lifted and check valve 86 opens to permit free passage of oil by way of pipe 8| into the bottom of the cylinder. Upon closing of the large bell,

the plunger moves downwardly into the cylinder 7 but as valve 86 is then closed the downward movement of the plunger forces oil from the cylinder by way of pipe 93 and valve 92 back into the reservoir. In a normal closing operation, the rate at which the bell is moved by the counterweight is determined by the rate at which drum' 30 is rotated by the motor 50. During such closing movement, the valve 92 does not offer sufficient restriction to the flow of oil to retard the closing of the bell. Should an explosion take place in the chamber between the bells, the large bell is blown open, pulling its counterweight upwardly. Oil flows as before by way of pipe 8| into the bottom of the cylinder as the upward movement of the plunger takes place so that the downward movement of the bell is not interfered with. This causes slack in roping 31 and as soon as the pressure in the chamber between the bells drops sufficiently the counterweight acts to close the bell. Without the retarder the speed of closing would be such that when the bell seats severe stresses would be set up in the rod, lever, roping and other parts of the apparatus, which might result in breakage of certain of the parts with consequent damage. The retarder acts, however, to cause the downward movement of the counterweight to be gradual and hence the closing of the bell to be below an objectional rate. This is due to valve 92 which regulates the flow of oil from the cylinder back to the reservoir and thus determines the speed at which the counterweight descends.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

In blast furnace charging mechanism havingv a small bell and a large bell; a counterweight for biasing the small bell to closed position; a counterweight 'for biasing the large bell to closed position; means for'opening each bell against the opening in the topthereof-ithrough which said connecting means extending from the side of said cylinder to said reservoir; and a second valve in said additional connecting means adjusted to restrict the flow of oil from said cylinder to said reservoir to retard lowering of said plunger in said cylinder by said large bell counterweight in the event the large bell is blown open by an explosion between the bells.

ARTHUR EDWARD HANDY. VALDEMAR BERTELSEN.

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