Improvements in and relating to Rolling Mills.
Year: 1889

page_text: Date of Application, 12th Oct., 1889-Accepted, 25th Jan., 1890
[Communicated from abroad by GUSTAV BRISKER, of Königshütte, Prussian Silesia,
in the Empire of Germany, Engineer.]
Improvements in and relating to Rolling Mills.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The rolling mills hitherto employed for rolling sheet-iron were either two-high
mills, in which the metal, after each pass was raised at the back and caused to come
to the front again, over the upper roll; or three bigh and reversing mills.
In all these mills, the necessity of raising the metal, or of reversing the rolls,
involves not only a considerable loss of time, but also a great waste of steam, and
lubricants, besides greatly increasing the wear of many expensive parts of
machinery.
The rolling mill herein described enables the work to be conducted in an easier and
more rapid manner than any other known type of rolling mill and at the same time
considerably reduces the cost of construction, operation and attendance.
The main feature of the improved mill is, that the metal, after passing between the
upper and the lower rolls, is, each time, caused to return to the front by simply
passing between the same rolls again, without its being necessary to alter the direction
of motion of the said rolls, as in the case of reversing mills. To enable this to be
done it is only necessary to provide means by which the lower roll can be caused to sink
a certain distance; and allow the metal to pass through when the said lower roll is
again raised to its former position.
Such operation of the lower roll can only be practically effected where the falling
and rising motion of the roll is as rapid, easy and secure as possible.
A rolling mill arranged as hereinafter described is calculated to fully answer
these requirements.
The invention is illustrated in the accompanying drawings the figures of which are
hereinafter referred to.
The upper roll, like those of most rolling mills now in use, is counterbalanced by
hydraulic cylinders CC, Figure 1, and an accumulator ; and it is also adjusted in
the ordinary manner.
The lower roll, on the contrary, is not permanently fixed in the framing as usual,
but rests upon separate blocks EE, with which it can be made to rise and fall as
required. Like the upper roll, the lower one can be counterbalanced by means of
two hydraulic cylinders and an accumulator P.. The weight of the lower roll is so
proportioned, however, as to cause the same to press with a slight excess of weight
upon the supporting pieces U U located between blocks E E and the framing of the
mill. These supporting pieces may be shifted by means of two pistons working in a
common steam cylinder G Figure 2.
Above the accumulator P another steam cylinder F is arranged, the piston-rod of
which, in its downward stroke, exercises direct-pressure upon the plunger of cylinder P,
whereby the lower roll is raised.
The distribution of both the cylinders F and G is effected by means of one common
lever.
The roll rises and falls in the following manner :-
When the metal has passed through the rolls to the back of the mill, the piston of
cylinder F descends a short distance, and thereby causes the lower roll to rise slightly
and supporting pieces U U to be withdrawn. As soon as this takes place, the piston
s relieved from pressure, and the lower roll sinks,

page_text: a,
b.
All this is brought about almost instantly by simply shifting the lever
When the metal has thus been made to return to the front, the said lever is moved
back to its former position, whereby the supporting pieces are brought back under the
blocks, and the piston of the steam cylinder F relieved from pressure. Owing to its
excess of weight, the roll again takes up its position upon the supporting pieces, and
another backward passage of the metal may then take place.
The principal upon which the distribution in the two cylinders F and G is based is
illustrated in Figures 1, 1ª, and 2.
The slide valves of both cylinders are connected by connecting rods 2 and 2, with the
hand lever a, b.
The slide-rod of cylinder F is provided with a small roller r at its lower end, and
is constantly pressed downwards either by steam pressure or by a weight, so that its
roller always rests upon rod z, which is provided with a recess or bend n.
When the distribution-lever is in the position a, b, the slide-valve of cylinder F is
raised to its uppermost position, so that the steam-inlet is closed, the piston is free
from pressure, the plunger of accumulator P is raised owing to the excess of weight
of the lower roll, and the supporting pieces are under the blocks.
But when lever a, b is shifted into the position indicated in dotted lines in c d,
roller slips into the recess n of connecting rod z, side-valve F is pressed down,
steam is enabled to pass over the piston which it presses downward, along with the
plunger of the accumulator P, and the lower roll is slightly raised; in which position
it remains while roller r travels over the bent portion of rod z.
The distribution lever a, b, at the same time, shifts also the slide-valve of
cylinder G, whereby steam is permitted to act simultaneously upon both pistons,
whereby supporting pieces U U are removed from under blocks E, E.
By this time the connecting rod z has moved to the right, a sufficient distance to
cause the roller r to rest on the raised portion of the rod again; whereby the
slide-valve is raised, the piston relieved from pressure, and the lower roll made
to descend.
If the distributing lever is moved to the position c, d indicated in dotted lines the
roller, during this back movement, slides first into the depression n, in the draw-rod Z;
the steam distributing slide valve for the cylinder F is pressed downwards, the steam
passes above the piston, presses the latter, and with it the plunger of the accumulator P,
downwards, and the lower roller is raised a little.
In this position the roller remains as long as the roller r of the slide-valve rod slides
in the depressed part n of the draw-rod Z.
During this time the steam-distributing slide valve for the cylinder G is also
displaced by the distributing lever through the agency of the draw-rod Z; the steam
passes simultaneously in front of both pistons and the two supports U U are drawn
from under the blocks at the moment when the blocks E E are raised with the lower
roller.
r
However, the draw-rod Z has been moved so far to the right hand side that the
roller of the slide-valve rod rises again from the depression n, upon the upper part
of the draw-rod; the steam-distributing slide-valve for the cylinder F is raised, thus
the steam piston is balanced and the lower roller sinks. The piece to be rolled can
now be pushed back from the rear to the front side.
When this has been done the distributing lever is again moved to the position a, b.
The depression n in the draw-rod Z moves to the left hand side, the roller r slides
down again, the slide-valve for the cylinder F is pressed down, the steam passes above
the piston and the lower roller is raised.
By the draw-rod Z the steam distributing slide valve for the cylinder G is reversed
at the same time, the steam passes between the two pistons, and the supports U, U are
pushed back below the blocks E. E.
Meanwhile the distributing lever has passed to the extreme position a, b. The
roller rises again from the depression n to the upper part of the draw-rod Z, the
slide valve for the cylinder F is raised, the steam-piston is balanced, the lower roller
descends and with its blocks E E bears firmly upon the supports U U. The

page_text: piece to be rolled can then pass between the rollers again, the upper roller having
been previously adjusted.
It will be seen that the distances o, o, and d b, which the corresponding parts of the
connecting rods travel under the action of the movable hand-lever; the length of
recess n in rod ; and the displacement of the slide valves of the two steam cylinders,
may easily be so proportioned as to precisely regulate the time of the first rising of
the lower roll, of the removal of the supporting pieces, and of the subsequent descent
of the said lower roll, or the re-insertion of the supporting pieces.
The steam-cylinder employed for shifting the said supporting pieces may be arranged
in front of the rolls, instead of under the lower rolls. In that case it will be sufficient
to employ one ordinary cylinder with one piston, and the supporting pieces are
operated, as shown in Figure 3, by means of chains passing over rolls R. R.
The length of the coupling spindles of the lower roll may be suitably proportioned,
and the spindles themselves properly counterbalanced.
'In consequence of the application of hydraule machinery for counterbalancing the
lower roll, and owing to the fact that the said roller only moves a very little distance
in rising say 60 millimetres, its up-and-down movements take place easily and without
any shaking, whatever the speed at which the work is carried on; and, as both the
displacement of the various movable parts and the work performed by the two small
steam cylinders F and G are very insignificant, the amount of steam and of lubricants
necessary to keep the improved mill in operation, are reduced to a minimum, which
advantage cannot be claimed for any of the rolling mills now in use.
The tables carrying the rolls are stationary. When heavy sheet iron is to be rolled,
motion is imparted to the table rollers, as in reversing mills by means of a small
additional engine, or by friction-rollers m, m, which receive the lower roll when it has
completed its downward movement; as shown in Figures 5 and 7.
The rolling mill described is chiefly designed for rolling heavy sheet iron; but in
order to adapt it for rolling lighter sorts of sheet iron as well, the following
arrangement has been devised. Where the tables are stationary, it has frequently
been found that the opening, which forms between them at the moment when the
lower roll descends, was too large for small slabs of metal; and in consequence thereof
the work was liable to be interfered with by the return of such slabs to the front.
To provide for such cases, the central portions of the tables are made capable of a
sliding movement.
At the moment when the lower roll sinks, both these movable portions of the
adjoining tables advance towards the roll and assume the position shown in
Figures 6 and 7.
As soon as the lower roll rises again, the said parts of the tables slide back to their
original positions as illustrated in Figures 4 and 5. The tables are operated in this
manner either by means of friction-rollers m m, Figures 5 and 7, or by one of the two
steam cylinders F and G, but in every case automatically, and precisely at the time
of the rising and falling movements of the lower roll.
The lower roll can, if desired, be made to rise and sink by means of screws,
arranged as follows.
Underneath the lower roll, screws S Figure 8 are provided in the framing.
Bevel gear-wheels R are arranged to turn within collars L, Figure 9, firmly attached
to the framing of the mill, and connected with the said screws S by means of keys, in
such a manner that the said gear-wheels, in revolving, cause the screws to move up
and down, while they, themselves, retain their position unaltered.
These wheels R are driven by other bevelled gear wheels mounted upon spindle w w
which receive their motion (through the medium of more toothed wheels, if required)
from a small reversing engine working at high speed, and quite independent of the
driving gear used for operating the upper roll.
The method of rolling with the assistance of a lower roll capable of a rising and
falling motion, as herein described, can also if necessary be made serviceable for
rolling blocks when it will prove equally advantageous.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign Correspondent I declare that what I claim is :-
First. A two-high rolling mill in which the metal after passing through to the back
of the rolls, is caused to return to the front by being again passed between the same
pair of rolls (i.e. between the upper and lower roll) without the necessity of changing
the direction of motion of such rolls; which result is obtained by causing the lower
roll to descend the required distance substantially as described.
Second. In combination with the rolling mill above referred to the mechanism, as
shown in the drawings, adapted to ensure the rising and sinking movements of the
lower roll; consisting in the combination of a hydraulic counterbalancing device for
partly counterbalancing the said lower roll by alternately increasing and decreasing
the weight on the accumulator, and in removable supporting pieces U arranged under
the blocks E carrying the lower rolls; and also in the method of distribution, the
principle of which is illustrated in Figure 1, as applied to two steam cylinders
F and G.
Third. In combination with the rolling mill above referred to the arrangement by
which the backward and forward sliding of the tables, or the central portions of such
tables, is effected, so that it takes place precisely at the same time as the lower roll
rises and sinks.
Fourth. In the rolling mill above described in the arrangement shown in Figure 8,
whereby the lower roll is caused to rise and fall by means of screws S, independently
of the driving gear used to operate the upper roll.
Dated this 12th day of October 1889
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.