Improvements in Rolling Mills.
Year: 1889

page_text: Date of Application, 10th Oct., 1889-Accepted, 11th Jan., 1890`
[Communicated from abroad by GUSTAV BRISKER, of Königshütte, Prussian Silesia,
in the Empire of Germany, Engineer.]
Improvements in Rolling Mills.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & 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 :-
This invention relates to rolling mills and consists of a number of sets of rolls
arranged one behind the other, each set containing two independent pairs of rolls
arranged one above the other.
The said invention is illustrated in the accompanying drawings the figures of which
are hereinafter referred to."
The method of arranging sets of rolls one behind the other is not, in itself, new, no
more than the use of two pairs of rolls arranged one above the other in the same set.
But it will be remembered that in all mills arranged according to the former system
as heretofore constructed the sets of rolls placed one behind the other only consist of
two rolls each so that one operation or pass only takes place in each set, while the
velocity of rolling is increased in the succeeding pairs of rolls, in order to prevent
the formation of loops. The latter result, however, is only obtainable with the
assistance of very complicated mechanisms of toothed wheels or other transmitting
gear; and it is very difficult, moreover, to maintain the proper relation between the
reduction of the diameter obtained at each operation or pass and the velocity of the
rolls. This, and the complicated nature of the gear, are causes of so many draw
backs in the rolling mills in question, that they are only employed to a very limited
extent.
In the mills as heretofore constructed in which two pairs of rolls were employed in
the same set, the rolls were arranged in a straight line one above the other; the
successive pairs of rolls being, by complicated connecting gear, consisting of toothed
wheels or other transmitting gear, also set in motion at a gradually increased velocity
for the purpose of avoiding the formation of loops; moreover the metal in those
mills, was conducted from the lower pair of rolls into the pair situated immediately
above, whence it was conveyed directly between the lower pair of the next adjoining
set of rolls, so that two separate "passes" had to be performed in each pair.
The use of these mills, has failed to become more general for the same reasons,
which prevented the more frequent employment of the type of mills mentioned
before.
Now the rolling mill hereinafter described is a combination of the two systems of
mills above referred to, in a form hitherto unknown. The inconveniences I have
pointed out in connection with those two arrangements are here prevented and upon
the whole, a rolling mill is obtained the fitting up and operation of which is both
simpler and cheaper.
As stated before, my improved rolling mill consists of a number of sets of rolls
arranged one bebind the other, each set consisting of two pairs of rolls mounted one
above the other in the same frame as shown in Figure 1.
Motion is preferably transmitted from one set of rolls to the other by means of
toothed wheels. To impart motion to the various rolls of each set, either diagonal-
toothed rollers may be employed resting in separate frames, as shown in Figure 2;
or toothed wheels of cast steel may Le mounted upon the prolonged gudgeons of the
roll shafts, and driven by wheels R, as illustrated in Figure 3.
Owing to the special arrangement described both pairs of rolls of one set move
with the same initial velocity. Figure 4 shows the method of driving the rolls of
the last set in rolling hoop iron the operation being assisted by loose rolls.

page_text: The operation of rolling in a mill constructed in the manner indicated, takes
place as follows:-
The billet is first roughed down to the desired section in an ordinary three-
high roughing mill V, Figure 2. The bar thus obtained, after its last pass through
the roughing mills, is at once introduced into set No. 1 of the finishing mill
Figures 1 and 2, between rolls 1 and 2. Upon leaving these rolls it is, by means
of an automatic guiding hereinafter described bent upwards and caused to pass
between the rolls 3 and 4; whereupon it is by means of an inclined guide con-
ducted back between rolls 1 and 2 again, in such a manner that it goes through
the "pass" next to that through which it had traversed before. Hence, by means
of a straight guide, it is conveyed into set No. II, in which, as well as in the
remaining sets, if any, the same guiding operations are repeated. It will thus be
seen that three passes are provided for in each set.
In the special case of rolling mills devised for the rolling of hoop iron, the last
set is provided with two pairs of smoothing rolls. The hoop iron passes from the
lower pair of rolls of the last set but one, to the upper pair of rolls of the last set;
then, on passing between rolls 3 and 2 of this last set, it gets between the lower
pair of rolls of the same, whence it issues as a finished article Figure 1. or the
iron band may, as shown in Figure 1º, be first inserted between the lower pair
of rolls of the last set, so that on passing between rolls 2 and 3, it is carried along
by the upper pair of the same set.
It may thus be seen that a loop is formed by the metal band, passing in succession
between the pairs of rolls forming each set.
While it is true that, as the metal passes through the consecutive sets of rolls, the
velocity of the latter increases, the acceleration is so proportioned however as to admit,
even in this case, of a considerable amount of looping, so that in contra distinc-
tion to the systems mentioned above, the work in my combination of rolls placed
at the same time above one another and in train, is accompanied by a constant
formation of loops.
The mechanism employed for guiding the metal from one pair of rolls to the
other, in the same set, is constructed as follows.
Between two plates S Figures 5 and 6, is arranged a fixed circularly bent piece u
and a fixed bent piece a provided with holes for fixing the said piece between the
plates S S. Another fixed bent piece o, and a curved link b hinged on pin i are also
arranged between the said plates.
With one of the levers is connected the lever which carries the rollers rr; on the
other hand to the end of this bolt which protrudes from the plate S is secured the
lever provided with the counterweight G.
These parts are retained between plates S by bolts, and may be removed to be
replaced by others. Their inner surface is flat in the case of hoop iron, while for
the rolling of wire their way or path should be half square and half oval, so that the
metal, in being guided by them, is automatically made to describe an angle of 90°,
similarly to what takes place when the metal is guided horizontally.
"
The connection with the "passes " between the rolls is formed by the guide-tubes
or sheaths and f¹.
Figure 5 shows the guiding device when closed, i.e. at the moment when the
metal passes from one pair of rolls to the other. The link b the upper half of which
is much thicker than the lower half is maintained in the position shown, by the weight
of its upper portion; which weight is regulated according to the desired section of
the metal rolled.
When the metal bar has travelled through the guide piece, the loop, formed by this
time, opens the hinged piece b and forces its way outward as shown by the dotted
lines in Figure 6; whereupon, as it becomes wider, it gradually descends in the
vertical direction.
A similar device is provided on both sides of the rolls, it being optional to guide
the metal either upwards or downwards; the guiding devices are only arranged
obliquely at the point where they are required to convey the metal from the upper

page_text: pair of rolls, in an inclined direction, into the adjoining pass of the lower pair. For
hoop iron they should in addition be correspondingly bent, as in that case, notwith-
standing the inclined position of the guide the admission and delivery of the metal
must be parallel with or at right angles to the rolls.
The straight guides situated between the consecutive sets of rolls are also provided
with hinged pieces or links p, Figure 1, opening downwards, and closing by means
of suitable levers and counterbalances so that here too, the loops, in coming out,
may be directed downwards.
All loops, whether formed in the sets of superposed rolls, or between the consecutive
sets, are caused to descend vertically into a narrow well T Figures 2, 3 and 4
provided in the brickwork foundation and extending throughout the centre of the
finishing mill.
B, B Figure 1 are wide iron channels by which the cooling water running down
from the rolls is carried out of the mill so that it cannot enter the well T.
To prevent the end of the metal-piece while it is being guided from one pair of
rolls to the other, or when conducted by a straight guide from one set of rolls to the
next, from dropping into well T and thus causing an entanglement with the loop
hanging in the well the following arrangement is employed.
At the point where the metal enters the guide, i.e. where it leaves the rollers, one
or two pairs of rollers +1, Figures 5 and 6, are located within the guide by which
the metal is conveyed from one pair of rolls to the other or within the straight
guide in case the sets of rolls are placed behind each other or in train. The lower
rollers are pressed with a determined force against the upper ones r by a counter-
balanced lever G.
The metal in entering the guide, must first pass between these rollers.
Thus, when the end of the rolled piece has left one pair of rolls, it does not slip
down into the well, but is retained by the rollers r, 1 until a loop is completed by the
action of the other pair of rolls.
The counterbalance by which the lower rollers are pressed against the upper ones,
so that the end of the metal piece is retained between them, can at any time he adjusted
in accordance with the weight of the one half of the loop, which hangs in the well.
According to the greater or less thickness and weight of this portion of the loop,
the force of pressure of the lower against the upper rollers must be increased or
diminished, so that the loop end may be effectively retained between them. And as
the thickness and rigidity of the heated piece of metal increases with the weight of
the hanging loop, the portion of the metal, which first reaches rollers will always
prove sufficiently rigid to make its way between these rollers without being flattened
out of shape.
If required, for rolling very soft iron, three pairs of similar rollers may bé arranged
in train i.e. one pair behind the other. In that case each pair has only to sustain of
the weight of the hanging loop; and, accordingly, the load supported by each of
the lower rolls is also reduced by 3, so that the strain of the passing piece of iron
on each pair of rollers is proportionately reduced, being equally divided between
the three pairs.
My improved rolling mill is characterized by the following advantages
(1) There being three "passes" provided in each set of rolls (except perhaps the
last set) the number of rolls, sets of rolls &c. may be considerably less, for a given
number of "passes" than would be required in any other rolling mill.
(2) The metal not being allowed to pass direct from one pair of rolls to the other,
but caused to "loop" under way, the numerous and complicated toothed wheels or
other connecting gear may be omitted; and all the difficulties are obviated, which
are unavoidably connected with mills in which the metal is made to pass from one
set of rolls to the other direct, with an increasing velocity of the rolls.
(3) A well being provided in the foundation, for the issuing loops to descend into,
all drawbacks generally attendant on the formation of loops are also avoided, as the
loops occupy no space above the bed plate of the mill. Besides any danger to the

page_text: operatives is done away with, and the cooling of the loops, owing to the heat
constantly prevailing in the space they enter, is reduced to a minimum.
Having now particularly described and ascertained the nature of the said
invention 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. In a rolling mill consisting of a number of sets of rolls arranged in train i.e.
one behind the other, the method of constructing each set of two pairs of rolls
arranged one above the other, but separated from each other.
Second. The provision of three passes in each set of rolls in the manner described.
Third. The formation of loops both between the pairs of rolls placed one above
the other, and between those arranged behind each other, and the provision of a
well or shaft in the brick-work foundation of the mill, for all the loops to descend
into, as they are formed.
Fourth. The arrangement between the pairs of rolls placed above each other, of an
automatic guiding device, to convey the metal from one pair to the other; such
device consisting of two vertical or inclined plates S, between which removable
curved guide pieces n, x and o are interposed, and of bent piece or link b burning on
a pivot this link being opened automatically by the widening back portion of each
succeeding loop, and closing the guiding device again, after the completed loop has
passed.
Fifth. The employment in the straight guides between the consecutive sets of rolls,
of pivoted links p, also enabling the loops to descend.
Sixth. The employment, in the guides arranged between the pairs of rolls in the
same set, as well as in the straight guides between the successive sets, of rollers ²,
the lower ones of which are pressed against the upper ones with a certain pre-
determined degree of force, so that the end of the piece of metal is retained between
these rollers and thus prevented from falling down the well.
Dated this 10th day of October 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.