Hoisting hooks used to lift, transport and dump metallurgical ladles

The hoisting hook assembly of this invention comprises a pair of parallel hook arms connected at their upper end to a bail with the hook arms each having an upper hook portion and a lower hook portion adapted to engage a single pair of ladle trunnion pins. This assembly permits existing cranes to transport and invert large ladles.

BACKGROUND OF THE INVENTION 
This invention relates to metallurgical ladles commonly used to transfer, 
treat and pour molten metals, such as steel. It relates particularly to 
hoisting hooks used to lift and transfer molten metal from a furnace to 
ladle treatment position or a teeming position where the molten metal is 
poured into ingot molds or a continuous caster. The ladle is then lifted 
and moved to a pit where the ladle is inverted to dump residual slag and 
skull from the ladle into the pit. 
Metallurgical ladles of the type used in the steel industry are large open 
top containers having a steel shell lined with refractory and a bottom 
pouring nozzle. A pair of trunnion pins are mounted on diametrically 
opposite sides of the steel shell to permit the ladle to be lifted easily 
in an upright position for transport and to be inverted 180.degree. to 
dump the slag and skull. 
Apparatus for tilting and dumping metallurgical ladles consisting of bottom 
linkage is described in U.S. Pat. Nos. 2,881,488 and 3,550,816. 
In recent years, steelmakers have increased the size of the ladles in a 
shop either to provide sufficient freeboard height for ladle treatment 
operations, such as reagent injection, or to accommodate increased furnace 
capacity. In many shops the lifting height of the ladle cranes to 
accommodate the larger ladles cannot be increased easily due to structural 
limitations in the shop building. The crane lifting height in the shop 
must be sufficient not only to allow the ladle to clear all objects in the 
path of its transport to the ladle treatment or teeming stations, but also 
to permit the ladle to be inverted over the pit while being dumped. 
SUMMARY OF THE INVENTION 
It is therefore an object of this invention to provide a hoisting hook 
assembly which permit larger ladles to be used in a shop without 
increasing the crane lifting height. 
It is a further object of this invention to provide a hoisting hook 
assembly which is able to lift and transport a ladle at two different 
elevations. 
It is a further object of this invention to provide a hoisting hook 
assembly that will permit a larger ladle to be inverted 180.degree. during 
dumping. 
It is a still further object of this invention to provide a hoisting hook 
assembly easily adaptable to all ladles now being used. 
It has been discovered that the foregoing objectives can be attained by a 
hoisting hook assembly comprising a pair of parallel hook arms connected 
at their upper end to a bail with the hook arms each having an upper hook 
portion and a lower hook portion adapted to engage the ladle trunnion pins 
.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THIS INVENTION 
FIG. 1 illustrates a metallurgical ladle 1 being hoisted by the hoisting 
hook assembly 2 of this invention in an upright position suitable for 
transporting the ladle or teeming the molten metal from the ladle. 
Ladle 1 is comprised of a steel shell 3 lined with refractory and having a 
pouring nozzle 4 in the bottom controlled by a stopper rod assembly 5. The 
ladle 1 is provided with a pair of trunnion pins 6 and trunnion blocks 7 
each positioned diametrically opposite to the other on opposite sides of 
the ladle 1. The trunnion pins 6 are positioned above the center of 
gravity of the ladle, whether full or empty, so that the top of the ladle 
will normally lie in a horizontal plane when it is lifted and transported 
by the crane hook assembly 2. 
A bridge type crane 8 traveling on elevated parallel rails 9, is used to 
transport the ladle from the furnace to a ladle treatment station or a 
teeming station in the shop. The crane 8 is provided with ropes 10 
attached to a bail 11 to which are connected a pair of parallel hook arms 
12 which hang suspended from the bail 11. The hook arms 12 are made of 
heavy forged steel and are shaped to form an arcuate upper hook portion 13 
and a lower arcuate hook portion 14 which are adaptable to slide along and 
engage the trunnion pins 6 as shown in FIGS. 1 and 2. 
The crane hook assembly 2 of this invention allows the crane operator to 
lift the ladle using the upper hook portion 13 to obtain maximum clearance 
between the bottom of the ladle 1 and the floor 15 when the ladle is used 
to transport or teeming the molten metal. 
When the teaming operation is completed, the ladle 1 must be dumped of any 
remaining slag and skull before the ladle 1 can be used again. To dump the 
ladle where the floor 15 to bail 10-11 headroom is limited, the ladle 1 is 
set on the floor and the trunnion pins 6 released from the upper hook 
portions 11 of the hook arms 12. The crane operator then places the lower 
hook portions 14 of the hook arms 12 around the trunnion pins 6. When the 
ladle 1 is lifted with the hook assembly 2 in this position, there is now 
sufficient clearance between the bottom of the bail 10 and the bottom of 
the ladle 1 to permit the ladle 1 to be inverted 180.degree. using a 
pivoted bottom link assembly 17 and an auxiliary hoist (not shown) as 
described in U. S. Pat. Nos. 2,881,488 or 3,550,816, and dump the slag and 
skull into a pit 18 slag container 19 as illustrated in FIG. 2. 
The centerline of the upper hook portions 13 and the lower hook portions 14 
of the hook arms 12 lie in a vertical plane. Their spacing on the hook arm 
12 will vary according to the size of the ladle, the configuration of the 
shop and the height between the shop floor and the crane bail. 
The crank hook assembly of this invention while simple in construction will 
eliminate the need to lower the shop floor or to raise the elevation of 
the crane rails 9 both of which are very expensive, in shops when they are 
modernized with larger ladles. 
While the present invention has been described and illustrated with our 
preferred embodiment, it will be appreciated by those skilled in this art, 
after understanding this invention, that various changes and modifications 
may be made without departing from the spirit and scope of this invention. 
It is therefore intended that all such changes and modifications will be 
included in the following claims.