Apparatus for oscillating a continuous casting mold

A continuous casting mold for casting strands is mounted in a mold table or other suitable mold mounting arrangement and is ocsillated by means of oscillation levers. The oscillation levers are mounted both at the mold table and also at a bearing block. To compensate the bearing play arising at the bearing locations a power or force-applying device is provided between the mold table and the bearing block.

BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved construction of 
apparatus for oscillating a continuous casting mold for the continuous 
casting of a strand. 
Generally speaking, the mold oscillating apparatus of the present 
development is of the type comprising at least one oscillation lever which 
is mounted at a bearing block and is also hingedly connected with a guided 
mold table or other appropriate mold mounting arrangement which supports 
the continuous casting mold. 
It is generally known in this technology to oscillate a mold along an arc, 
in order to thereby prevent any binding or sticking of the continuously 
cast strand which is formed within the mold and the mold wall which serves 
to shape such cast strand. Oscillation of the continuous casting mold 
improves the surface quality of the cast strand and prevents metal 
break-out from arising. 
In U.S. Pat. No. 3,822,738 there is disclosed a prior art mold oscillation 
device which contains one or two short oscillation levers which are 
pivotably mounted at a bearing block. These levers are also hingedly 
connected with a mold table at which there is mounted a continuous casting 
mold. By means of an oscillation drive and a lifting rod the short 
oscillation levers are moved about their bearing locations in the bearing 
block. 
During the oscillation of molds for casting slabs, especially at high 
speeds amounting to about more than 100 strokes per minute, vibrations in 
the mold oscillation system arise due to the high inertia forces and the 
prevailing bearing play at the bearing locations at the mold table. This 
impairs the quality of the cast product. 
A further prior art oscillation device is disclosed in U.S. Pat. No. 
3,343,592. Also with this state-of-the-art mold oscillation equipment it 
is possible for vibrations to occur during the casting of a strand. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind, it is a primary object of the 
present invention to provide a new and improved construction of mold 
oscillation apparatus for a continuous casting mold which is not 
associated with the aforementioned drawbacks and limitations of the prior 
art construction. 
Another and more specific object of the present invention aims at providing 
a new and improved construction of mold oscillation apparatus for a 
continuous casting mold which ensures for an exact and relatively 
vibration-free oscillatory movement of the continuous casting mold even 
when operated at higher oscillation speeds. 
A further significant object of the present invention is directed to a new 
and improved construction of apparatus for oscillating a continuous 
casting mold, which mold oscillation apparatus incorporates means for 
compensating the bearing play of the mold oscillation system so as to 
afford relatively accurate and vibration-free oscillatory movements of the 
continuous casting mold even when the same is oscillated at relatively 
high oscillation speeds. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
mold oscillation apparatus of the present development is manifested by the 
features that there is provided a mold table at which there is mounted a 
continuous casting mold. This mold table is supported and guided during 
the oscillation movement by two short oscillation levers. These two short 
oscillation levers are hingedly connected at one of their respective sides 
or ends by means of shafts with the mold table and are pivotably mounted 
at the other respective sides or ends thereof, again by means of shafts, 
at a rigidly or fixedly arranged bearing block. An oscillation drive 
serves to move or swivel one of the short levers about bearing locations 
thereof in the bearing blocks. Importantly, a power or force-applying 
device is operatively connected with the bearing block and the mold table 
in order to produce a force which extends or is effective approximately 
parallel to the direction of extent of the levers in order to continuously 
press the shafts in a defined direction at the related bearing location 
during the oscillatory movement, and to thereby thus compensate for any 
existing bearing play. 
In this way, there can be applied compression or tension forces which 
compensate the bearing play at the bearing locations in that the shafts of 
the oscillation lever, mounted pivotably at the bearing, are pressed in a 
defined direction even while taking into account the weight of the mold 
table and the mold. Also in the presence of high inertia forces, which can 
arise during considerable oscillation speeds of more than about 100 
strokes per minute, there is prevented the occurrence of vibrations in the 
oscillation system, and thus, there is beneficially ensured for quiet 
running and a good quality of the cast product.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Describing now the drawing, it is to be understood that only enough of the 
construction of a continuous casting machine or installation has been 
shown to enable those versed in the art to readily understand the 
underlying principles and concepts of the mold oscillation apparatus of 
the present development. Turning attention now to the single FIGURE of the 
drawing, there will be recognized a conventionally driven drive, here in 
the form of a driven eccentric 1 which cooperates with a lifting or 
reciprocable rod 2 or equivalent structure and acts upon a short mold 
oscillation lever 3 which, like a further short oscillation lever 5, is 
rotatably mounted in a bearing or support block 4 or equivalent structure. 
Each of both oscillation levers 3 and 5 is rigidly connected with a 
respective shaft 8 which is hingedly guided at both ends in suitable 
bearings, merely generally indicated by reference character 20, at the 
mold table 7. The expression "mold table" is used in its broader sense to 
encompass any suitable mold mounting or support structure as is 
conventionally employed in the continuous casting technology. Mounted upon 
the mold table 7 is a continuous casting mold 6, which in the embodiment 
under discussion serves for casting a steel slab 11. The mold table 7 and 
the continuous casting mold 6 are supported by the lower lever 3, and the 
upper lever 5 performs a guiding function during the mold oscillation 
movement. Both of the levers 3 and 5 each engage at both sides of the mold 
table 7. In place of the lever 5 the mold table 7 also could be guided by 
another guide structure, such as a slide guide arrangement. 
According to the invention, a suitable power or force-applying device 10 is 
arranged between the bearing block 4 and the mold table 7 at the central 
region of such mold table. The power or force-applying device 10 may be 
advantageously in the form of a pressurized fluid medium cylinder 
arrangement 10, such as a hydraulic cylinder unit, which is hingedly 
connected at locations 22 and 24 at both the mold table 7 and the bearing 
block 4. This pressurized fluid medium cylinder arrangement 10 extends 
approximately parallel to the levers 3 and 5. There also could be provided 
two pressurized fluid medium cylinders arranged at each respective side of 
the mold table 7. By means of the cylinder unit 10, with the embodiment 
under discussion, there is exerted a pressure force upon the mold table 7. 
Consequently, the shafts 8, during the oscillatory movement of the 
continuous casting mold 6, are continuously pressed in a defined direction 
at the bearing locations during the mold oscillatory movement, and thus 
there is compensated for any prevailing bearing play. Hence, even at 
higher oscillation speeds, there is rendered possible an exact, 
vibration-free oscillatory movement of the continuous casting mold 6 in 
the strand withdrawal direction, and thus, there is obtained an 
improvement in the surface quality of the continuously cast strand 11. 
Without the benefit of the arrangement of the inventive power or 
force-applying device 10 at low oscillation speeds the weight of the mold 
table 7 would be effective upon the top surface or side of the shafts 8 
and with a bearing play of, for instance, 0.05 to 0.2 mm there would be 
possible a quiet oscillatory movement along a prescribed arc or circular 
path of travel. Yet, at higher mold oscillation speeds the weight of the 
mold table 7 and that of the mold 6 no longer would act upon the top side 
or surface of the shafts 8 and the surfaces of the shafts 8 against which 
there is applied the weight load would then be displaced towards the right 
and left of the showing of the drawing. As a result, there would arise 
vibrations of the mold table 7 along with the disadvantageous consequences 
heretofore discussed. 
Instead of exerting a pressure or compression force as employed in the 
exemplary embodiment under discussion, there also could be applied a 
tension force which is exerted by the pressurized fluid medium cylinder 
unit 10. Instead of using a hydraulic cylinder arrangement it would also 
be possible to employ a spring as the power or force-applying means or 
device. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims. Accordingly,