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Патент USA US2113050

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April 5, 1938.
L. IVERSEN
2,113,050
ROLLING MILL AND METHOD OF OPERATING THE SAME
Filed June 14, 1935 -
4 Sheeis-Sheet l
a
A
5
/
INVENTOR
[Lama-1M?
April 5, 1938.
|__ NERSEN
‘
2,113,050
ROLLING MILL AND METHOD OF OPERATING THE SAME
Filed June 14, ‘1955
fig’. 3 -
E
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J3
4 Sheets-Sheet 2
April 5, 1938.
L. IVERSEN
2,113,050
ROLLING MILL AND METHOD OF OPERATING THE SAME
Filed June 14, 1955
4 Sheets-Sheet 3
Apl‘ll 5, 1938.
|_. IVERSEN‘
2,1 13,050
ROLLING MILL AND METHOD OF OPERATING THE SAME
Filed June 14, 1955
4 Sheets-Sheet 4
INVENTOR
m
‘Patented Apr. 5, 1938- >
v
2,113,050
UNITED STATES PATENT OFFICE
2,113,050
'
ROLLING
MILL AND METHOD OF OPERAT
ING THE SAME"
Lorenz Iversen, Pittsburgh, Pa., assignor to Mesta
Machine Company, Pittsburgh, 2a., a corpora-
’
tion 01' Pennsylvania
Application June 14, 1935, Serial No. 26,588
3 Claims. (01. 80-38)
In the accompanying drawings illustrating cer
This invention relates to rolling mills and the
operation thereof and is herein particularly de-'
tain preferred embodiments of the invention,
scribed as applied to a mill of the 4-high_ type for
strip rolling. The rolling of strip, especially if it
5 has a high ratio of width to thickness, entails the
‘use of very high roll pressures and consequently
the roll neck bearings are subject to extremely
Figure 1 is a side elevation partly broken away .
showing a mill of the 4-high type having my in
vention applied thereto;
high unit loads. This fact has militated against
Figure 2 is a horizontal section to enlarged
scale through the mill of Figure 1 taken ,on a
plane tangent to the bottom of the bottom back
the use of bearings of the lubricated journal type,
ing roll;
10 and roller bearings have been employed to a con
siderable extent. There are numerous advan
tages in bearings of the lubricated journal type
but they are open to the objection that when the‘
mill is standing idle the pressure of the roll neck
15 against the journal bearing squeezes out most of
the ?lm of lubricant. - While it takes only a rela
tively short time to re-establish the ?lm after
the mill has started‘up, the wear attendant upon
starting and re-establishing the ?lm may be con
20 siderable, under extreme conditions the non
driven rolls may even refuse to turn, and varia
tions in the thickness of the ?lm may adversely
affect the gauge of the product. The difficulty
is particularly marked on the bottom roll of the
25 mill because the‘weight of the roll is exerted
Figure 3 is a transverse vertical section show
ing the roll balancing mechanism in more detail;
Figure 4 is a section on the line IV—IV of Fig—
ure 3;
.
Figure 5 is a view corresponding to Figure 3
but showing a modi?ed form of construction;
Figure 6 is a'view corresponding to a portion of
Figure 5 but to enlarged scale and partly broken
away;
‘
‘
Figure '7 is a section on the line VII—VII of
Figure 5;
Figure 8 is‘ a view corresponding to Figure 3
but showing a still further modi?cation; and
Figure 9 is a section on the line IX——IX of
Figure 8.
.
The mill illustrated in Figures 1 to 4 inclusive
comprises housings 2 having windows 3 therein in
which are mounted backing rolls 4 and 5 with
intermediate work rolls 6 and 'l. The backing
rolls have necks working in chocks 8, the bearings
downwardly and tends constantly to break the
?lm of lubricant. The di?iculty is not met in the
bearings of the top roll because the top roll is
thrust upwardly while it is working and, of course,
30 it tends of its own weight to drop away from the being of the lubricated journal type. Suitable
upper part of the bearing 'shell and is restrained oil connections are indicated at 9. A highly
only by the lower part of the shell. ‘In conse-2 satisfactory form which the bearing} may take is
quence there is no tendency to break the ?lm at more speci?cally described and’ claimed in my
the point where it is most required for the top roll. copending application Serial No. ‘727,701, ?led
85 Where mills of the backed-up type are used, the May 26, 1934. The necks of the working rolls 6 :1
bearings of the bottom roll must carry the dead » and ‘l are carried in chocks Ill. The several
weight of the backing roll or rolls as well ‘as the chocks are all vertically slidable in the windows
3 of the housings. The spacing of the rolls dur
weight of the bottom work roll.
ing rolling is determined by the usual screw
It is well recognizedihat a, bearing of the lubri
40- cated journal type is subject to practically no _‘
When the mill is ‘standing idle the weight of
wear so long was the oil ?lm is maintained; but
the problems peculiar to rolling mill practice have the bottom rolls is borne by the lower bearings
down-ll.
limited the applicability of bearings of this type.
The present invention, by doing away with the
45 principal cause for breakdown of the oil ?lm,
vastly enlarges the ?eld of applicability of such
bearings. I eliminate the tendency toward
breaking down of the oil ?lm due to weight of
.the rolls by balancing out the .. eight of the roll
50 in large measure and particularly of the bottom
roll.
Roll balancing means, broadly speaking,
are well known, but such roll balancing devices
do not function to lessen the unit pressure on the
bearings and minimize the tendency toward
55 squeezing out or breaking down the ,oil ?lm.
8.
'
'
'
.
In a modern mill this weight may be as much >
as 125,000 pounds. Such a load tends to squeeze
the oil out of the’ bearings so that the oil ?lm is ‘
ruptured or else will rupture immediately on
starting up and before the rolls have rotated
' su?iciently to entrain a fresh supply of oil, carry
it into the journal, and re-establish or renew
the ?lm. In order to reduce the load on the bear
ings of the lower roll, the roll is engaged exter
nally of the journal surfaces and urged upwardly.
In this form-of the invention the balancing is '_
accomplished by means of a thrust roller l2 run
ning on bearings l3 mounted on a spindle I4. 55
2
2,113,050
The thrust roller I 2 bears against the working
face of the bottom roll 4 and extends over a sub-,
stantial portion of its width.
The surface of the
roll 12 is highly ?nished and does not mar the
hardened surface of the backing roll. It runs
freely on its bearings so that there is no tend
ency to scratch even if any foreign particles
should accidentally be entrained on the roll sur
faces. Provision‘ is made at I5 for lubricating the
10 bearings l3. The spindle I4 is carried in a slide
38 which is movable vertically in a casing ll sup~
ported between the housings 2. The casing l'l
contains nested coil springs “3 which exert an
upward force against the roll 4. This force is not
15 sufficient to lift the weight of the bottom roll out
of its bearings but is sufficient to reduce in great
measure the pressure exerted on the oil ?lm in the
the “journal type” or of the “lubricated jour
nal type”, I have intended to refer to those bear
ings wherein the shaft has sliding as distin
guished from rolling friction with its supprting
surface, and I mean to include not only babbitt
lined bearings but bearings of other material
and construction, as, for example, water-lubri
cated bearings made vof composition material.
While I haveillustrated and described cer
tain preferred embodiments of my invention, it 1O
is to be understood that the same is not limited
thereto but may be otherwise embodied and
practiced within the scope of the following claims.
I claim:
I
1. In the method of operating a rolling mill
having rolls including a bottom roll with roll
neck bearings of the lubricated journal type,
bottom journal bearings.
the steps consisting in intermittently rotating
The springs act against the slide l6 through
collars l9 and the collars slide on studs 20 hav
ing bottom ?anges 2| which lie below‘ the bot
the rolls and rolling material in the mill, resist
ing the rolling force transmitted through the 20
bottom roll by means of the neck bearings, and,
tom ends of the springs.
at least during those times when the bottom roll
Heads 22 on the studs
limit the expansion of the springs l8. This per
mits' of initially compressing the springs l8 so
that they are contained in a relatively small
compass. vThe length to which the springs can
expand is correspondingly limited and there
fore the amount of upward movement of the
rolls I2 is limited. It is not intended that this
limit of movement shall be reached so long as
the mill rolls are in place, but when it becomes
necessary to change the mill rolls it is impor
tant that there be some such limit on the amount
of upward movement of the roller 12.
Figures 5 to 7 illustrate a modi?ed form of con
struction in which the roll I20. is carried in bear
ings‘ on a spindle Ma, the spindle being urged
upwardly by hydraulic plungers 30 working in
cylinders 3|. The cylinders 3| are formed in
a casing Ila lying between the housings 2a and
are connected through passages 32 to a conduit
33 which is connected to a ‘controlled supply of
fluid ‘pressure. With this form of apparatus, the
upward movement of the roller l2a is,‘ limited
when a roll change is to be made by merely cut
ting off the ?uid pressure.
Figures 8 and 9 show still another modi?cation
it not rotating, yieldingly applying to the body
of the roll an upward force limited in amount
to less than the dead weight of the bottom roll
but equal to a substantial part of said weight,
thereby substantially lessening the unit pres
sure in the bearings and limiting the extrusion
of lubricant under such dead load, thus to insure
the presence of a lubricant ?lm in the bearings 30
adequate to supportthe rolling load on resump
tion of rolling in the mill.
2. In the method of operating a rolling mill
having rolls including a bottom roll with roll
neck bearings of the lubricated journal type, the
steps consisting in intermittently rotating the
rolls and rolling material in the mill, resisting
the rolling force transmitted through the bot
tom roll by means of the neck bearings, and, at
least during those times when the bottom roll is
not rotating, yieldingly applying to the body of
the roll an upward force limited in amount to less
than the dead weight of the bottom roll and the
parts supported thereby but equal to a substan
tial part of said weight, thereby substantially
llll movable up and down in a casing l'lb sup
lessening the unit pressure in the bearings and
limiting the extrusion of lubricant under such
dead load, thus to insure‘the presence of a lu
bricant ?lm in the bearings adequate to support
the rolling load on resumption of rolling in the
ported between the housings 2b.
mill.
wherein the pressure roller l2b is mounted on a_
spindle Mb which, in turn, is carried by slides
The bottom
of each slide 40 is engaged by one arm M of a
lever pivoted at 42. The longer arms 43 of such
levers are connected through links M- to‘ a coun
55 ter-weight 45. The levers constitute a multiply
ing system whereby with a weight of reasonable
.
3. In the method of operating a rolling mill
having rolls including a bottom roll with roll
neck bearings of the lubricated journal type,
the steps consisting in intermittently rotating
the rolls and rolling material in the mill, resist
ing the rolling force transmitted through the
size a considerable upward force can be exerted.
In this case the- upward movement of the roller
l2b is limited by the engagement of faces 46 on
60 the arms 4| of the levers with cooperating faces
41 on the housing l'lb.
It is often necessary to redress the surfaces of
the mill rolls and during the life of a roll there
bottom roll by means of the neck bearings, en
gaging the body of the roll with a pressure roller
and yieldingly applying to the body of the roll
through said pressure roller an upward force
limited in amount to less than the dead weight
of the bottom roll but equal to a substantial part
is 7a corresponding reduction in weight, which
weight reduction is often considerable in amount.
‘Preferably the upward force exerted by the bal
the unit pressure in the bearings and limiting
the extrusion of lubricant under such dead load,
6.5
ancing means is slightly less than the minimum
thus to insure at all times the presence of a In
weight of the roll, with due regard to dressing
bricant ?lm in the bearings adequate to support
the rolling load.
down of the roll body.
'10
of said Weight, thereby substantially lessening
,
Where I have referred herein to bearings of
LORENZ IVERSEN.
70
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