IMPROVEMENTS IN ROLLING MILLS
Year: 1875

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN ROLLING MILLS."-A communication from abroad
by Ignatius Hahn, of Pittsburg, Pennsylvania, in the United States
of America.
COMPLETE SPECIFICATION filed by the said John Imray at the Office
of the Commissioners of Patents, with his Petition and Declaration,
on the 18th August 1875, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
ROLLING MILLS," and have petitioned Her Majesty to grant unto me,
my executors, administrators, and assigns, Her Royal Letters Patent
for the same, and have made solemn Declaration that it has been

page_text: communicated to me from abroad by Ignatius Hahn, of Pittsburg,
Pennsylvania, in the United States of America.
NOW KNOW YE, that I, the said John Imray, do hereby declare that
the following Complete Specification, under my hand and seal, fully
describes and ascertains the nature of the said Invention, and in what 5
manner the same is to be performed, in and by the following statement,
reference being had to the accompanying Sheet of Drawings and to the
figures and letters marked thereon, that is to say :-
This Invention relates to the construction and operation of rolling
mills, more especially plate mills, and it consists, -
1st. In the combination of three small work rolls with one large roll
to the outside of and in line with each of the outer work rolls, the
central roll being of an equal or less diameter than its next adjoining
ones.
2nd. In combining with the outer bracc rolls three intermediate work 1
rolls of less diameter, one or more of the intermediate rolls being driven
by belting from the main rolls so as to obtain circumferential speed of
the rolls.
3rd. In an arrangement of the belting and a series of fixed and
moveable pulleys over which the belting passes, whereby the belting
will be kept tight and will pass the intermediate rolls against the
circumference of the next outer roll, and the use of counterweights to
take up the slack of the belting is avoided.
4th. In applying the belting around the whole circumference of the
pulley of the intermediate rolls, whereby the movement of the pulley is a
made to take up the slack of the belting and an increased contact
between the pulley and the driving belt is obtained.
5th. In the combination of a feed table and three or more rolls
adjustable in relation to one another and to the table by means of
hydraulic power for regulating the pass.
6th. In combining with an adjustable roll a hydraulic piston and
cylinder and a series of pipes for admitting fluid to both sides of the
piston so that the roll may be raised or lowered and held stationary by
hydraulic power.

page_text: may
preferably formed with upper and lower sections which may be separated
by liners that can be changed to take up the wear of the rolls. The lower
sections of the boxes or riders g are slotted or recessed to receive the neck
of the intermediate roll b, which is held in position up against the outer
roll by straps f, the ends of which pass through lugs upon the upper
section of the boxes, whereby any wear of the journals or rolls be
readily corrected. These boxes are secured to stems h of pistons i
which work in cylinders m secured to or formed in the cross pieces n of
the housings. c is the independent moveable intermediate roll journalled
in boxes or riders p, which boxes may be made in sections, as above
specified, and are secured to pistons », r. Instead of employing pistons
and cylinders the intermediate moveable roll may be operated by counter-
balances from below acting on the rider if preferred. d and e are the
lower intermediate and outer rolls, provided with the boxes or riders g
and pistons and rods h', ', corresponding in detail with the upper pairs
of rolls excepting that the slings or straps fare omitted as not necessary
from the position of roll d, the upper section of boxes g being slotted
for the necks of the intermediate roll which rests upon the outer roll e.
The rolls are mounted in suitable housings which slide upon the bed
plate, and where very long rolls are employed it is preferred to construct
the housings in six separate pieces, as shewn in the Drawings, four jamb
pieces o, o, o¹, o¹, and two cross pieces, one at the top n and another at
the bottom n¹, the several parts being cast and planed, the jambs o, o, o¹, o',
with lugs and recesses as seen at o², o³, (Fig. 1) whereby the bolts and
rods which secure the parts are in great degree relieved from undue
strain. By this means large housings can be readily cast and built up,
the cross pieces n, n', being tied by long wrought-iron or steel rods
applied close to the line of strain where they are needed, and the jamb
and cross pieces may be further strengthened and secured by wrought-
iron or steel rods, bolts, or ties. For raising, lowering, and adjusting
the rolls the housings are provided with cylinders, either by bolting
them to the cross pieces or by boring out the latter themselves, the
pistons i, ¹, r, having rods which are secured firmly to the boxes or
riders of the several rolls. Water, steam, or other fluid may be admitted
to the cylinders m on both sides of the piston i by means of pipes l, k,
and to the under sides of the pistons i, r, by means of the pipes ¹, k¹,
the flow of the fluid and its direction in the pipes being governed by a
series of valves, as shewn in Fig. 4, compactly arranged on a common
axis, and by valves of the respective pipes.

page_text: It will be seen by reference to Fig. 4 that there are three pipes D, K,
and N leading from the accumulator and communicating through the
valve box with the pipes l, k, l, k¹, and two waste pipes E and L, which
likewise communicate with pipes l, k, l, k¹, all of which are controlled
by valves Z, Z, H, and J; part of the said valves operated by the hollow
stems x, x, and part by solid stems F, F'. The pipes land k are connected
by a double check valve n and branch pipe M, arranged on the pipes at a
point near the inlet valves, by which means the admission of fluid to
the under side of the upper piston causes an equal amount to be
displaced above..
The manner of operating the rolls, arranged so far as already described,
may be understood on reference to Figs. 1, 2, and 4.
Fig. 1 shews the position of the rolls for the pass going from A to B
through between the intermediate rolls b and c, at which time the valves
8, t, and u (Fig. 1) are shut, as is also the upper valve of the double
check valve w (Figs. 1 and 5). At the moment the pass is complete
from A to B an attendant turns the hollow stem x (Fig. 4) inwards by
revolving the hand wheel y, which is fastened to x, thereby operating
the two valves and 2', which are cast in one piece, with the hollow
stem y, closing z', and opening (as seen in Fig. 4), thereby shutting off
communication with the waste pipe E and opening communication with
D leading from the accumulator. The valve s is then opened (Fig. 1),
which admits the fluid to the under side of the piston and forces up
the rider g of the lower rolls. When the lower rolls d, e, have arrived
at the position shewn in Fig. 2, which can be determined by proper
graduations or marks on the housings, the attendant shuts the valve 8,
confining the fluid between s and the piston ¹, and the rolls d and e
will then be in permanent position, resting on the fluid. This accom-
plished, the attendant turns the solid valve stem F (which passes
through the hollow stem x) outwards by means of the crank G secured
to the outer end of F, thereby operating the valves H and J, closing H,
and cutting off communication with the waste pipe E and opening J,
establishing communication by means of the pipe K between the
accumulator and the pipe l', which leads to the under side of the
piston r. The valve is then opened, admitting the fluid through ¹
(Fig. 1) to the under side of the piston r, lifting the rider p and inter-
mediate roll until the lowest point of the circumference of c is as
much above the upper surface of the roll d as the desired reduction for

page_text: the next pass amounts to, which point may also be determined by marks
or graduations; the valves t and J are then closed. The upper rolls
have been previously lifted by turning outward the solid valve stem F¹,
with its valves and ³ closing the waste pipe L, and opening com-
munication by means of the pipe K between the accumulator and the
under side of the piston i; the valve u also being opened and the valves
and operated by the hollow stem a¹ so as to open the waste pipe L
and close the pipe N leading to the accumulator. The fluid passing
through the pipe k enters the branch pipe M and forces up the double
check valve v, allowing the fluid above the piston i to escape through
the pipes 1, m', and waste pipe L at the same rate as fluid enters below
the piston.
As soon as the box or rider has reached its proper place
the valve u is closed, and the several rolls occupy the position shewn in
Fig. 2, which is the position they occupy on the second or return pass
from B to A, the bloom now passing between the rolls c,
d. The pass
from B to A having been accomplished the intermediate roll c is
lowered down on the roll d, and the exit valve of pipes and ¹ is
opened to allow the escape of fluid from beneath pistons ", r, and i as
the rolls sink by their own weight until the top of the roll c is again on
the level of the table C, when the exit valves of pipes and ¹ are
closed; simultaneously the exit valve to the pipe leading to the
under side of the piston is opened allowing the rolls a, b, to descend
the required distance. When the valve of the pipe k is closed, and fluid
admitted by the pipe to the cylinder above the piston i the exit of lis
closed, and the rolls arc again in the position shown in Fig. 1 ready for
the pass from A to B.
The manner of driving the different rolls is shewn more particularly
in Figs. 6, 7, and 8, illustrating the arrangement of the belting whereby
the tension is preserved, while at the same time the adjustability of the
rolls is not interfered with, and this without counterweights for taking
up slack. S (Fig. 3) is a pinion coupled to the fly wheel shaft, gearing
into a pinion I, coupled to the bottom roll c by breaking spindle U, thus
driving the lower outer roll e direct.
It is evident that the intermediate rolls may, if preferred, be driven
direct by this or similar gearing. On the end of the roll e, Fig. 6, is a
pulley V driving by a belt pulleys V¹, V, V³, V* (V* being on the neck
of the lower intermediate roll d) V³, Vº, and V back to V, thus driving
the shafts W, W¹, W³, and W³ below and above on the housings, as well

page_text: as the intermediate roll d. Of this combination four of the pulleys
V¹, V³, V, and V' are stationary, while the pulleys V and V* move with
the rolls, as do also the pulleys V³ and V5, which are secured to the box
or rider of the rolls d and e, and it will be thus seen that any slack
arising from the movement of the rolls in one direction must be taken
up by the increase in the distance between the fixed and moveable points
on the opposite side. On the shafts W, W', W%, and W³ (Figs. 1, 3,
and 7) are pullies x¹, ³, x', and a* respectively, pullics x, x³, on rolls
a, b, and pullies x and x8 (loose on shafts y¹, y), so that the power from
the lower driven roll communicated by the belting, which drives the
roll d to the shafts W, W, is thence transmitted to the upper rolls a, b.
The arrangement of the pullies and belting shewn in Fig. 7 is similar
to that already described in reference to Fig. 6. The independently
adjustable intermediate roll c is driven as follows:--On the lower shaft
W (Fig. 8) is a pulley 2º connected by belting over a pulley 2¹, which is
loose on a pin y' to on the neck of the intermediate roll c, thence by
3, which is loose on the pin y to z on Ws and back over z² again to 2º,
so that the belting is applied around the whole circumference of the
pulley, whereby increased contact between the belt and the pulley is
obtained. Here, as in the previous cases, the relation of fixed and
moveable pulleys is preserved, and it is obvious that whatever belting is
loosened by the upward or downward movement of the rolls is imme-
diately taken up on the side of the rolls opposite to the direction of
travel. For the purpose of tightening the belts the lower shafts W and
W are hung in moveable bearings, and operated by screws U¹, mitre
wheels c', shafts p³, worm wheels n³, worms M², and hand wheels M³, so
that the weight of the lower shafts and pullies assists in tightening the
belts, while by this method of driving the outer intermediate rolls are
always kept tight against the circumference of the large rolls next
adjoining.
As one of the main objects of the present Invention is to use rolls of
greater lengths than have heretofore been employed, and as while it is
practicable to obtain the small intermediate roll of the required length,
it is not at present everywhere practicable to obtain the larger or outer
rolls of sufficient length, sectional rolls a, e, may be constructed as
shewn in dotted lines on a Fig. 3, represented in longitudinal section to
an enlarged scale in Figs. 12 and 13. These rolls are built up of two or
more independent parts and then properly secured together, as for
instance as illustrated in the lower roll e (Figs. 3 and 12) where B' is a

page_text: central shaft formed in one piece and provided with three collars B¹, B²,
B³, turned thereon, and having three separate rings M, M, M³, shrunk
on the shaft B* whose collars prevent the rings from moving laterally.
In the upper roll a (Figs. 3 and 13) the three separate pieces U2, U³,
U', are fitted together by boring or casting the inner ends of U³ and U'
to match projections u² formed on the middle section U2; the sections
being secured together by screw threads on ² or by a central bolt U*
extending the whole length of the roll.
For either of the rolls a, e, above described a roll made of longitudinal
staves bolted to a central shaft and confined by shrinking bands thereon
may be substituted. In order that the diameter of the central shafts of
such sectional outer rolls may be reduced, the shaft may be driven from
both sides sides as shewn (Fig. 3) in the case of the central intermediate
roll c, in which case each half length of the shaft transmits only half the
power, and the shaft can therefore be made of less diameter than when
the roll is driven from one side only. The several parts of the sectional
rolls may be made of cast iron, wrought iron, or steel, to suit circum-
stances. The same may be said of the intermediate or small rolls b, c, d,
though these latter are preferably made in one piece, of cast iron if short,
or wrought iron and steel if long, the latter metals being less liable to
break, and offering greater resistance to torsional strain than cast iron.
The trusses employed with the outer rolls and which will be herein-
after described, should support the sectional outer rolls at the junction
of the sections.
The advantages to be gained from the use of a five high mill as above
described are illustrated by Figs. 9, 10, and 11, of which Fig. 9 shews
the ordinary two high mill; Fig. 10 a three high mill, having a small
intermediate roll; and Fig. 11 is the five high mill, in which the small
intermediate rolls are placed between larger rolls above and below.
•
In all the Figures the pile Q is shewn of the same size and subjected
to the same reduction.
The surface of contact between the pile and the rolls being divided
into a certain number, say for instance seven equal divisions, each of
which may represent an inch. There are in Fig. 9 seven inches of
contact with the upper roll, seven inches of contact with the lower roll;
total, fourteen inches of contact with both rolls; in Fig. 10 there are
seven inches of contact with the upper roll, six inches of contact with

page_text: the intermediate roll; total, thirteen inches of contact with both rolls; in
Fig. 11 there are six inches of contact with the roll b, six inches of
contact with the roll c; total, twelve inches of contact with both rolls.
If the rolls were all of equal lengths, say nine feet, rolling sheets of the
same width as it takes about 5,000 pounds pressure per square inch to
roll metal 3,780,000 pounds power would be required at the circum-
ference of the rolls in Fig. 9, 3,510,000 pounds at the circumference of
the rolls in Fig. 10, and 3,240,000 pounds at the circumference of the
rolls in Fig. 11, so that fifteen per cent. less power is required in the
five high mill than in the ordinary two high mill, and eight per cent.
less power than in three high rolls with small intermediate rolls, even
supposing that all three of the intermediate rolls in Fig. 11 are of the
same diameter as the intermediate roll in Fig 10. But owing to the
mode of attaching the two outer intermediate rolls b and d to the large
rolls a and c they need not to be made so large as the intermediate roll
in Fig. 10, so that there would be an additional gain in power or the
same amount of power could be applied to work a larger roll. Where
for instance a roll nine feet long might be the limit, as employed in Figs.
9 and 10, the arrangement of Fig. 11 would permit the use of rolls of the
same diameter ten feet long, but as according to this Invention there are
never less than two rolls below or above the pile or bloom the strength
of these rolls has to be considered from a different stand point. In Fig.
10 there is always on one side, either above or below the pile, a single roll
which has to take the strain, consequently the ordinary three high mill
is no better than the two high mill as regards capacity of the rolls to

page_text: in length, but as the outer intermediate rolls always bear tight against
their next adjoining larger rolls the strength is increased as the square
of the height, so enlarged from 32 to 32 and 16, or from 1 to 1½, that is
to say 2 times.
The length of the rolls after making deductions for the increased
strain on the rolls by increased width of sheet to be rolled might there-
fore be 16 feet. By trussing these rolls, either by simple trusses R, as
shewn on the lower roll Fig. 3, or by hydraulic pressure, their length
might readily be increased, so as to make plates for pipes, boilers, beams,
tanks, &c., all in one piece, which can then either be bent and rivetted on
one longitudinal line only, or else bent and welded, finishing for example,
a boiler with no rivetting whatever except for securing the ends.
Trusses are applied to the large rolls in the following manner :- Upon
the lower roll e (Figs. 2 and 3) the simple form of truss is employed,
secured to the roll or some object travelling with the roll, as for instance
the riders, while in the upper roll the truss is connected with pistons
which follow the roll. For the upper roll there is provided a cap or
clutches D³ having friction rollers d³ bearing against the face of the roll;
these caps or clutches being secured to piston rods D³, which terminate
in pistons ², ³, working in cylinders secured to the upper cross piece of
the housings.
و
The different pipe lines k and are continued to connect with the
cylinders both above and below the pistons 2, 3, as in the case of the
cylinders i, ¹, of the housings proper, and the pistons 22, ³, are operated
in the manner specified for i, i. For the lower roll bed pieces D' having
friction rollers d' bearing against the face of the lower roll are provided,
and these bed pieces may be operated by extending pipes and k¹ to
cylinders secured to the bed, or by other suitable devices, but however
operated sufficient provision should be made by bracing the bed piece or
its rod D to prevent lateral displacement.
Where the metal to be rolled is not so heavy but that it can be readily
handled and lifted, either the rolls d, e, may be made with stationary
riders, or the roll c may be stationary. In the former case the roll c
moves up and down as do also the rolls a, b; in the latter instance a, b,
and d, e, move in pairs to and from the central roll c, so that if, for
example, the bar should go through between the rolls b and c, then the
rolls dande must rest tight against the circumference of c to prevent it

page_text: from breaking, and if the bar is passing between the rolls c and d, then
the rolls a, b, must rest tight against the circumference of c, and this for
the reason that the roll c is made only sufficiently strong to resist the
torsional strain to which it is exposed while work is being performed.
In cases where but two intermediate rolls are employed one pass will
be between both intermediate rolls, while the return pass will be between
one of the intermediate rolls and its next adjoining outer roll or rolls;
and in such an arrangement of rolls as well as in two high rolls where a
single roll is subjected to great strain the rolls may be trussed with good
effect.
here only two intermediate fons are employed the fons o anu a may
be driven direct by suitable belting or gearing.
To prevent accident or injury to the rolls, where unusual strain comes
upon them from any cause, safety valves are applied on the line of pipes
close to the rolls.
The mechanism herein specified may be varied to suit circumstances
of existing machinery and to utilize the same; properly proportioned
gearing may be applied to obtain equal circumferential speed of outer
and intermediate rolls; keys, screws, or steam pressure may be employed
for bracing the rolls, all of which being of common knowledge may bo
applied without departing from the spirit of this Invention.
Among the advantanges of the described arrangement of rolls may be
cited one incident to two high reversing rolls that is avoiding the
necessity of lifting the piece to be rolled; and another incident to three
high rolls, viz., working both ways without reversing the direction of
the rolls, both of these advantages being derived from such means as are
always required for regulating the distance between the rolls for each
succeeding pass of the pile or bloom, or for keeping the rolls at such
predetermined distance while the bar is passing through the rolls.
By making very long rolls in sections and putting them together or
building them up, as shewn on roll a (Fig. 13), the middle section
may be removed and a short idler inserted in its place, and the housings
can be moved up so as to reduce the size of the mill at such times as the
largest size plates are not being rolled, thus avoiding the necessity of
investing capital in extra rolls of different lengths.

page_text: Having thus described 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 claim the following improvements in
rolling mills,
First. The combination of three small work rolls b, c, and d, with one
large roll to the outside of and in line with each of the intermediate
rolls b, d, the central roll c being of equal or less diameter than its next
adjoining one b, d, substantially as and for the purpose specified.
Second. In combination with the outer brace rolls one or more inter-
mediate work rolls of less diameter driven by belting, substantially as and
for the purpose specified.
Third. In combination with the adjustable rolls and the belting for
driving the same a series of four or more fixed pullies secured to the
housings or arranged relatively thereto, for the purpose of equalising the
belting, substantially as herein described.
Fourth. In combination with a pulley secured to the shaft of a driven
roll, four or more fixed pulleys and the belt for driving the roll, the belt
being applied to the entire circumference of the pulley of the driven
roll, substantially as and for the purpose specified.
Fifth. The combination of the adjustable rolls b, c, and d, having
suitable riders with pistons working in cylinders formed in or secured to
the housings for raising and lowering the rolls, substantially as
specified.
Sixth. The combination of a fixed feed table and three or more rolls
adjustable in relation to one another and to the table, substantially as
and for the purpose specified.
Seventh. In combination with an adjustable roll a hydraulic piston
and cylinder, and a series of pipes for admitting fluid to both sides of
the piston, so that the roll may be raised and lowered and held stationary
by bydraulic power, substantially as and for the purpose specified.
Eighth. In combination with the outer roll of a series, one or more
trusses secured to or travelling with the roll, substantially as and for the
purpose specified.
Ninth. In combination with the outer rolls a, e, the hydraulie

page_text: trusses D³, D*, having suitable pistons working in cylinders, substantially
as specified.
Tenth. In combination with the fixed table three or more adjustable
rolls and mechanism for raising and lowering the rolls, substantially as
and for the purpose specified.
Eleventh. The combination of four pairs of inlet and outlet valves, all
mounted in a common axial line, each pair secured to a common shaft
and independent of the others, the outlet valves of each two pairs
communicating with a common outlet pipe, and the inlet valves of the
two intermediate pairs communicating with a common inlet pipe, sub-
stantially as and for the purpose specified.
Twelfth. The use of housings formed of a series of three or four jambs
and cross pieces secured by wrought-iron or steel bolts, substantially as
and for the purpose specified.
Thirteenth. The use of a check valve w in combination with a double
line of pipes leading to the side of the piston against which the pressure
is exerted, substantially as and for the purpose specified.
Fourteenth. In combination with the line of pipe leading to the rolls,
one or more safety valves placed at a point near the rolls, substantially
as and for the purpose specified.
In witness whereof, I, the said John Imray, have hereunto set
my hand and seal, this Eighteenth day of August, in the
year of our Lord One thousand eight hundred and seventy-
five.