Note: Descriptions are shown in the official language in which they were submitted.
GOK-109-156
lZ30764
BACKGROUND OF THE INVENTION
This invention relates to the rolling of a metal strip
such as aluminum strip in a rolling mill stand and to a
means for preventing a substantial amount of liquid applied
to the rolls from entering into a gap in a non-rolling
area of the work rolls while the strip is being rolled,
and the removal of any liquid finding its way to the
delivery side which may be through the non-rolling area.
In the cold rolling of metal strip, such as aluminum,
liquid lubricant or coolant is applied to the work rolls
and to the strip for a number of reasons, some of which are:
to reduce the wear of the work rolls; to improve the
surface quality of the strip; to reduce frictional heat
generated during the rolling process, etc. The coolant
applied to the work rolls lands onto the top and bottom
surfaces of the stip. Usually this coolant or lubricant
is an oil-in-water emulsion. If this water base liquid
remains on the surface of the strip for any length of
time it has a tendency to stain or mar the strip, which
condition is undesirable for many commercial purposes.
Therefore, as disclosed in U.S. patent No. 3,192,752
to Dowd et al dated July 6, 1965 wherein upon the strip's
exiting from a four stand continuous Eour-high mill and
prior to the coiling of the strip, a means and method
has been devised to remove as much lubricant as possible
from the strip's surfaces. This is done by arranging a
plurality of air jets above and below the strip and
directing these jets onto the strip and adjacent the work
rolls on both sides of the strip in a manner to blow the
rolling lubricant and any free water off the sides of the
strip toward the sides of the mill where an exhaust system
collects and withdraws the air as well as the emulsion
and water. Further on down the mill line and still prior
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~230764 GOK-109-156
to the recoiling of the strip, again air is applied to the
top and bottom of the strip while an exhaust system removes
the liquid emulsion.
Several disadvantages and problems arise from the design
disclosed in the '752 patent which present invention at least
substantially resolves. One of the limitations of the '752
design is that on the delivery end of the mill a consider-
able amount of liquid remains on the strip after it has
passed beyond the air jets.
It was concluded that this condition was due to the
following:
As is known in the rolling process, coolant is applied
to the work rolls prior to the strip's entry into a stand
of the mill. Since the coolant cannot pass between the rolls
in the area engaging the strip there is a tendency to create
a puddle or a buildup on top of the strip immediately
adjacent the roll bite on the entry side. Some of this
buildup of liquid runs off on both sides of the strip and
finds its way onto the delivery side of the stand. One way
in which this happens is that the liquid passes through the
rolls in the open space of the roll gap extending from the
edges of the strip outwardly toward the roll necks. The
rotation of the rolls results in the coolant being thrown
into the air and landing on the strip downstream of the
air jet system of the '752 patent. Therefore a considerable
amount of liquid is on the strip even after the strip has
passed through the air jet area.
In essence, the air jet system of the '752 patent
does not remove most of the liquid off of the strip when
it is most advantageous to do so.
SUMMARY OF THE INVENTION
It is, therefore,an object of the present invention to
123~764 GOK-109-156
provide a means and a method to retain and remove from the
strip most of the liquid on the entry side and remove from
the strip the remaining liquid on the delivery side of
either a continuous tandem rolling mill or a single stand
of a rolling mill so that the rolling area remains free
from excessive liquid, thereby preventing any marring to
the surfaces of the strip.
It is a further object of the present invention to
prevent the liquid from escaping from the entry side of the
mill to the delivery side, and the removal of any liquid
which passes through the rolls onto the delivery side.
A still further object of the present invention is to
create a clean and tidy working area on both the entry and
the delivery sides, making it conductive to the operator's
inspection of the shape and appearance of the strip exiting
from the stand.
And yet a still further object of the present invention
is to provide a method and an apparatus for using the
method, the apparatus being used in a strip rolling mill
stand having a strip entry and a strip delivery side thereof
wherein a strip is reduced in a rolling area between work
rolls defining a roll bite and a strip passline along
which strip travels generally horizontally and non-rolling
area where a gap is created from edges of said strip outwardly
toward the ends of said work rolls and wherein liquid
lubricant applied to said rolls on said entry side
accumulates on the upper surface of said strip on said
entry side, comprising: lubricant directing means having
a support mountable adjacent to said non-rolling area on
the entry side of said mill and including pressurized
medium applying means carried by said support located in
the vicinity of the edges of said strip having means for
1230764 GOK-109-156
directing pressurized medium across at least a portion of
said upper surface of said strip in a manner to force
said accumulated liquid toward the center of said strip
and prevent it from falling off the edges of said strip.
These and other objects of the present invention will
become more apparent when the following description is
read along with the accompanying drawings of which:
Fig. 1 is a schematic showing in exaggerated form a
strip between the work rolls;
Fig. 2 is a schematic, elevational view of a 4-high
roll stand employing the present invention in the roll stand;
Fig. 3 is an elevational partly cross-sectional view
of a strip entry guide incorporating the present invention
on the entry side of the stand;
Fig. 4 is a sectional view of the top portion of the
strip entry guide taken along lines 4-4 of Fig. 3;
Fig. 5 is an elevational partly sectional view of a
strip delivery guide on the delivery side of the stand
incorporating the present invention;
Fig. 6 is a sectional view of the top portion of
the strip delivery guide taken along lines 6-6 of Fig.5;
Fig. 7 is an elevational, partly sectional view
taken along lines 7-7 of Fig. 5;
Fig. 8 is an elevational partly sectional detailed
view of the bottom portion of the strip delivery guide
including a longitudinal frame;
Fig. 9 is a sectional view of the bottom portion of
the strip delivery guide taken along lines 9-9 of Fig. 8;
and
Fig. 10 is a partly sectional elevational view
taken along lines 10-10 of Fig. 8.
DETAILED DESCRIPTION
Fig. 1 illustrates the basic problem of a build-up
~Z30~64 GOR-109-156
occurring when coolant is applied to the strip on the
entry side. This view is seen if one looks into the mill
from the entry side while the strip S travels between
the upper and lower work rolls ~R. Crosshatched lines
indicate in exaggerated form a gap or field F defining a
non-working area between the edges of the strip and the
ends of the work rolls. On the portion of the strip S
immediately preceding rolling thereof an accumulation or
puddle P of lubricant occurs. The continued action of the
strip travelling between the work rolls causes this lubri-
cant to flow down alongside the edges of the strip to make
its way into field F and onto the delivery side of the mill.
Figs. 2 through 10 illustrate the present invention.
A four-high stand of a rolling mill is shown. It is to be
noted that the system of the present invention can be used
in conjunction with a single stand or several stands of a
continuous tandem mill and the stand or stands may consist
of more or less than four rolls. The long arrow in several
figures of Figures 2 through 10 indicate the direction of
the strip's travel.
It will be further appreciated that many of the
components of the rolling mill stand and the rolling mill
per se are well known in the art.
Of Figs. 2 through 10, in describing the present
invention Fig. 2 will be referred to first. A roll stand
14 of a cold rolling mill has two back-up rolls 16, 18
supporting two work rolls 20, 22 which form a roll bite
through which an aluminum strip S passes along the passline
of the stand for reduction. The area of the rolls in contact
with the strip is the rolling area, and that not in contact
is referred to as the non-rolling area. Located adjacent
to work rolls 20, 22 are entry strip guiding means 24 and
~30764 GOK-109-156
delivery strip guiding means 26, which guide the strip
between the work rolls along the passline of the mill.
Strip guiding means 24 on the entry side of the stand 14
is mounted to a bridle roll assembly 28 in which Fig. 2
and Fig. 3 shows two rolls 30 thereof, and which bridle is
movable between housing posts (one indicated at 29 on
the entry side) toward and away from the roll stand by
means, not shown. Strip guiding means 26 is mounted to the
housing post of the delivery side of the stand 14 (one
10, of which is shown at 32 in Fig. 5) in a manner to be
discussed later for movement in a horizontal direction
towards and away from the rolls and in a vertical direction
towards and away from the strip. Coolant or lubricant is
applied to the work rolls 20, 22 by spray units 34 located
on the entry side of the stand. After the strip exits
from between the work rolls, it either passes to another
stand or is coiled on a coiler (not shown).
As already mentioned, a constant problem in the cold
reduction of metal strip, particularly aluminum, involves
the accumulation of lubricant from spray units 34 occurring
on the strip prior to the strip entering the roll bite.
In the present invention, positive medium, such as pre-
ssurized air or fluid from strip guide means 24 retains
most of this accumulated liquid on the strip prior to the
strip entering the roll bite, and any atomized lubricant
escaping to the delivery side and landing onto the strip
due to the rotation of the rolls is removed by both
positive and negative air pressures applied by the strip
guiding means 26 on the delivery side of the mill.
Figures 3 and 4 show in greater detail the entry
strip guiding means 24. It consists of upper portion 36
and lower portion 38 between which the strip travels.
230764 GOK-109-156
~oth these portions 36, 38 consist of a member 40 extending
the width of the housing posts 29. On both sides of member
40 along the ends of the roll bodies of work rolls 20,
22 is a nozzle assembly member 42 which is machined to be
fitted and bolted into member 40, and which consists of
two rows of nozzles running parallel to the roll body
surfaces (Fig. 4). The length of nozzle assembly 42 is
such as to accommodate both the maximum and minimum width
strip. As can be seen in Fig. 3 the opening of nozzles
44 in upper portion 36 extends entirely through member 42,
whereas those of lower portion 38 extend a short distance
downwardly onto the underside of member 42. The openings
of nozzles 44 are angled in such a manner as to deliver
positive air pressure in a direction towards the center
of the rolls and the strip. This direction is clearly
indicated by the three converging lines extending from
the nozzles 44 in Fig. 4. The nozzles in upper portion
36 direct air against both the top work roll surface and
along the outer top surfaces or edges of the strip, and
the nozzles in lower portion 38 direct positive air to
the surface of the lower work roll 22. The nozzles 44 are -
angled towards the center of the strip and rolls so that
the lubricant is caused to remain on top the strip and on
the work rolls.
Mounted to the other end of members 40 are a number
of air solenoid valves 46. Fig. 4 shows the air solenoid
valves 46 which are connected to one or more drilled
longitudinal channels, which in turn, communicate with
two nozzles 44. As seen in Fig. 4 the nozzles located on
the extreme ends of the nozzle assembly member 42 are
interconnected to longitudinal channels 48 through
traverse channels 50.
lZ30q6A GOK-109-156
Member 40 of upper portion 36 is bolted to the side of
the bridle assembly 28 through a bracket 52. For simplifi-
cation only one end of member 40 is shown, but it is to be
understood that the other end of this member 40 is
symmetrical about the centerline of the strip. It is
also to be understood that the construction and arrangement
of the lower portion 38 and its mounting to the bridle,
although not shown in a plan view, is similar to that
of the upper portion 36.
Each of the air solenoid valves 46 can be regaulted
to deliver positive air pressure according to the width
of strip being rolled.
For instance, as the maximum width strip is being
rolled thereby creating a minimum length of gap from the
edges of the strip to the ends of the roll bodies, the
nozzles at the far end of the work rolls and strip will be
operated since even though a minimum length of gap exists,
y~ it is still desirable to prevent lubricant from leaving
the ends of the two L~L]. roll bodies and to avoid the
strip nozzles 44 from removing too much lubricant off
of the strip which is required for rolling, particularly
as to the upper guide assembly portion 36. If the minimum
width of strip is rolled thereby creating a maximum length
of gap then all the nozzles will be operated. In this case,
the roll nozzles 44 allow their maximum effectiveness in
preventing lubricant escaping from the ends of the roll
bodies. IN both instances the nozzles are selectively
operated through a control 54 to deliver positive air
pressure to force the lubricant in a direction toward the
center of the rolls, and in the case of the upper nozzle
assembly 42, towards the center of the strip.
~Z~0~64 GOK 109-156
Most of the accumulated liquid on top of the strip is
caused to be carried away from the rolling area in a direction
opposite to that of the strip's travel away from the rotating
elements of the rolllng area.
As mentioned previously, from the edge of the strip
outwardly along the length of the roll, a gap or non-
rolling area is formed which would under ordinary circu-
mstances permit lubricant to pass between the work rolls
onto the delivery side of the stand. Due to the present
invention and the selectability of the operation of the
air valves notwithstanding the width of the strip, positive
air pressure is applied along this roll gap along the
length of the rolls to direct the lubricant to the center
area of the strip and rolls thereby preventing a
substantial amount of liquid from leaving the entry side
of the stand.
For efficiency, the nozzle-air valve arrangement of
the lower entry guide portion 38 would be operated in phase
with the nozzle-air valve arrangement of the upper entry
guide portion 36.
Figures 5 through 10 will be referred to in describing
the strip guiding means 26 on the delivery side of the
stand 14. Again for simplicity, Figures 6, 7, 9 and 10
show only one side of the delivery guiding system approxi-
mately along the centerline of the strip, and it is to
be understood that the delivery strip guiding system is
symmetrical about this centerline.
A general overall design of the strip delivery guiding
means of the present invention is shown in Fig. 5. It
consists of an upper and a lower portion 56, 58, respectively,
which portions guide the strip passing through the rolling
area onto the delivery side.
1~30~A GOK 109-156
A detailed description of the top portion 56 of
delivery guide will be given first. In referring to
Figures 5, 6 and 7 top portion 56 consists of two members
60, 62 which span across the width of the stand. Member
60 is located immediately adjacent the rolling area and
supports an air nozzle assembly 64 consisting of a row
of nozzles, which assembly 64 does not entirely extend
to the centerline of the strip but whose length is such
to accommodate the maximum and minimum width strip being
rolled. The nozzle assembly 64 parallels those of the
strip entry guiding means 24 (Fig.4). Positive air is
delivered to the nozzles of nozzle assembly 64 through
line 66.
- Member 62 supports two nozzle header assemblies 68,
70 each consisting of a row of nozzles separated by members
72 into three groups. Positive air is delivered to each
group by individual lines 74, and each group can be
operated according to the width of strip being rolled,
more about which will be explained later. Each nozzle
is interconnected for passage of air to the other nozzles
in their respective group by means not shown. Air
pressure outlet 78 of all the nozzles of the three nozzle
assemblies 64, 68, 70 extend downwardly toward the top
surface of the strip through an opening 76 in members 60
and 62. Each nozzle is constructed so it can be adjusted
by adjuster 80 to deliver positive air at various angles
relative to the strip and the positive air pressure
ejected by the nozzles is indicated by the three diverging
lines extending from the nozzle shown in Fig. 6.
In addition to nozzle assemblies 68, 70, member 62
has welded thereon three enclosures 82, 84, 86, each
spaced apart by nozzle assemblies 68 and 70. As seen in Fig.
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~2307~4 GOK-109-156
6 each nozzle assembly 68, 70 is a unit and is mounted to
member 62 by suitable means (not shown) and can be removed
and replaced as such in the space provided between these
three enclosures. In viewing Fig. 5 it can be seen that the
enclosure immediately located to the left of each
nozzle assembly has an opening 88 along the underside of
the top portion 56 directly above the passline of the strip.
In Fig. 6 these openings 88 can be seen to actually be a
slot several of which run along member 62 to the center-
line of the strip. Each slot 88 extends the distanceoccupied by two adjacent nozzles. A circular opening 90 in
each enclosure provides for the connection of a hose 92
which delivers negative air pressure to the enclosures 82
and 84.
Fig. 6 indicates that nozzle header assemblies 68 &
70 and enclosures 82 and 84 slant downwardly from right
to left toward the centerline of the strip. Using this
centerline as a focal point the nozzle assemblies and the
enclosures on the other side of member 62 would run
upwardly from right to left in a similar manner as that
shown, thus, the left side of member 62 is a mirror image
to that of the right shown in Fig. 6. In an overall view
of the top portion these nozzle assemblies and enclosures
on member 62 form a chevron configuration across the
width of the stand. This chevron configuration angles
the nozzles in a manner that the positive air pressure
forces the lubricant adhering to the top surface of the
strip away from the center towards the edges of the strip.
Also the nozzles of nozzle assembly 64 are angled for the
same reason, i.e., to force the lubricant towards the edge
of the strip.
The operation of the top portion of the strip delivery
GOK 109-156
~230~64
guide means is as follows. Positive air pressure is delivered
through the nozzles of nozzle assemblies 64, 68 and 70 and a
vacuum is created in enclosures 82 and 84. Immediately
adjacent to the rolling area the nozzles of nozzle assembly
64 directs the lubricant towards the edges of the strip
where it is removed by a vacuum system, more about which
will be explained shortly. Nozzle assembly 70 cooperates
with vacuum enclosure 82 and nozzle assembly 68 cooperates
with vacuum enclosure 84 to remove the lubricant from the
top surface of the strip. In addition to diverting the
lubricant to the edges of the strip, the force of the
positive air pressure initially loosens any adhering
lubricant. It then carries this loosened lubricant along
with the flow of liquid towards the edges of the strip
where most of it is drawn up through suction slots 88 in
enclosures 82 and 84. Members 60 and 62 are interconnected
through sidewall member 92 which has projections 94 and 96
which in turn fit into a U-shaped slide 98 bolted to a
plate 100 mounted on the side of the housing post 32. As
seen in Fig. 6, member 62 is pivotally connected at 102 to
sidewall member 92 so that through piston cylinder assembly
104 (shown in Figures 5 and 7), it can be pivoted relative
to member 60. For simplicity, this movement is not shown
in phantom in any of the Figures 5, 6 and 7, and would be
initiated for threading of the strip through the stand.
Cylinder 104 is supported through bracket 106 by a circular
member 108 extending across the width of the stand which
circular member is bracketed and, fastened into side wall
member 92 of top portion 56.
Both members 60 and 62 of top portion 56 are moved
as a unit away from work rolls 20 and 22 through a linkage
system 110 which is pivotally connected to piston cylinder
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~2307~;4 G0K-l09-l56
assembly 112 located on both sides of top portion 56 (only
one piston cylinder assembly 112 is shown in Fig. 6). This
piston cylinder assembly 112 is mounted by bracket 114 to
the side of the housing post 32 at one end and connected
to a clevis member 116 of linkage system 110 at the other
end. This clevis member 116 pivots on an equalizer shaft
118 extending the width of the stand and connected through
bearing 120 mounted to a bracket 122 on the side of the
housing. As shown in Fig. 5 slide 98 runs at an angle
relative to the mill passline. Through the operation of
piston cylinder assembly 114 top portion 56 moves upwardly
in slide 98 in a horizontal positio~ as seen in Fig. 5. This
movement is generally initiated for work roll changing
purposes.
In the discussion of the lower portion 58 of strip
delivery guiding means 26 reference will be made to Figures
8, 9 and 10. This lower portion 58 consists of nozzle
assemblies 124 and 126, which, similarly to the nozzle
assemblies 68 and 70 of top portion 56 consist of nozzles
separated by members 128 into three groups of nozzles.
In viewing Figure 8, to the left of nozzle assemblies 124
and 126 is an enclosure 130, 132 respectively. A series of
slots 133 in lower portion extend along the length of each
enclosure 130 and 132, and continuous openings 134 in
lower portion 58 receive air outlets of the nozzles of
nozzle assemblies 124, 126. Two vacuum hoses 136 connected
to circular openings 140 deliver negative air pressure to
each of the vacuum enclosures 130, 132. Similar to the top
portion, the nozzles and enclosures of the lower portion
form a chevron configuration across the width of the stand.
Positive air from the nozzles loosens the lubricant from
the undersurface of the strip and forces most of it towards
GOK 109-156
~Z30764
the edges of the strip where it is drawn downwardly away
from the pass line. Both the top and bottom vacuum or
negative air systems include means (not shown) which
carry the liquid lubricant away from the delivery side
area of the stand.
Lower portion or member 58 has a projection 142
shown in Figures 9 and 10 which fit and is guided
through a U-shaped slide 144 mounted through plate 146
to the side of the housing 32. Mounted in the two traverse
slots 147 of lower portion 58 for traverse movement therein
as shown in phanton in Fig. 9 is a rectangular vacuum
enclosure 148, which extends beyond the length of lower
portion 58 into the roll gap. The portion of this enclosure
148 extending between the immediately adjacent to the rolls
20 and 22 has an opening for receiving any lubricant coming
between the rolls. Vacuum enclosure 148 is positioned
immediately alongside the edges of the strip leaving only
enough space so that the strip does not come into contact
with the enclosure 148. A further discussion of the enclosure
will be given shortly.
Movement of the lower portion 58 away from the rolling
area is initiated through a linkage-piston cylinder as-
sembly similar to that described for the top portion 56.
Fig. 10 shows a half portion of the section taken
along lines 10-10 of Fig. 8. Piston cylinder assembly 150
is pivotally connected at one end to a bracket 152 mounted
to the side of housing 32 and to a clevis member 154 at the
other end.Clevis member 154 is pivotally mounted to an
equalizer shaft 156 extending the width of the stand, which
shaft 156 is mounted by bearing 158 and bracket 160 to the
side of the housing. The effected horizontal movement of
the lower portion 58 in slide 144 is partially shown in
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GOK- 109-156
~Z30'764
phantom in Fig. 8.
The precise location of rectangular box 148 relative
to the edge of the strip is shown in Figs~ 7 and 10. It
projects from the work rolls 20, 22 and extends beyond the
length of the delivery guide means 26 as shown to the
right Fig. 9 where a hose 162 is connected thereto. On
the inside of rectangular box adjacent to the edge of the
strip is a series of angular slots 164. Travers movement
of rectangular box is initiated through a rack and pinion
arrangement 166 powered through a coupling and motor
arrangement 168 to provide width positioning of the boxes
to accommodate the various strip widths. It is important
to locate the enclosures 148 as close to the edges of
strip as possible so that the liquid along the edges can
be drawn off. All nozzles of nozzle assembly 64 are
operated irrespective of the width of strip being rolled to
cause the lubricant along the strip's edges to be forced
into the vacuum chambers 148.
Each of the groups of nozzles in the nozzle assemblies
68, 70, 124, 126 in the upper and lower portions 56, 58
can be controlled individually or simultaneously according
to the width of strip being rolled as explained for the
strip guiding means 24 on the entry side of the stand. If
a minimum width strip is being rolled then perhaps only
the two groups located outwardly from the centerline of the
strip when viewing Figures 5 and 9 will be operated. If a
maximum width is to be rolled all groups will deliver
positive air to the strip. The groups of top portion 56
corresponding with those of the lower portions 58 can either
be operated in phase or out of phase.
Upon operation of the nozzle assemblies 124, 126 and
enclosure systems 130, 132 of the lower portion 58, positive
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~Z30764 GOK 109-156
air against the undersurface of the strip loosens and forces
the lubricant toward the edges of the strip. Enclosure 130
cooperates with nozzle assembly 124 and enclosure 132 co-
operates with the nozzles of nozzle assembly 126 to draw most
of the lubricant off of the under surface of the strip. Any
lubricant escaping along the edges of the strip on both
its top and bottom surfaces is drawn into the rectangular
vacuum chambers 148 and carried away from the strip area
by means, not shown.
The interrelationship and operation of all components
of the present invention provides for the optimization
of the removal of lubricant away from the rolling area
particularly on the entry side and surface of the strip
on the delivery side of a stand.
In accordance with the provisions of the patent
status, I have explained the principle and operation of
my invention and have illustrated and described what I
consider to represent the best embodiment thereof.
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