GB2111885A - Removing liquid from strip in a rolling mill - Google Patents

Abstract

A substantial amount of liquid lubricant used in a cold strip rolling mill is prevented from remaining on the strip by locating an entry guide on the entry side and employing several zoned air nozzles which deliver a positive pressure to force the liquid in a direction toward the centre of the strip, and which nozzles are controlled according to the width of strip being rolled. The relatively small amount of liquid finding its way on to the delivery side is removed from the strip by providing in the strip exit guide both positive and negative air pressure means located above and below the strip, and negatively pressurised longitudinal enclosures located adjacent both edges of the strip and the said area at the ends of the rolls. <IMAGE>

Description

SPECIFICATION Method of, and apparatus for, removing liquid from a strip in a rolling mill This invention relates to the rolling of metal strip, such as aluminium strip, in a rolling mill stand and to ways of 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 aluminium, 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; and to reduce frictional heat generated during the rolling process. The coolant applied to the work rolls is transferred to the top and bottom surfaces of the strip. Usually, this coolant or lubricant is an oilwater-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 3192752 with strip exciting from a four stand continuous four-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 surfaces of the strip. This is done by arranging a plurality of air jets above and below the strip and directing these jets on to 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 to the recoiling of the strip, again air is applied to the top and bottom of the strip while an exhaust system removes liquid emulsion.

Several disadvantages and problems arise from the design disclosed in the '752 patent. One of the limitations of the '752 design is that, at the delivery end of the mill, a considerable amount of liquid remains on the strip after it has passed beyond the air jets. 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 build-up on top of the strip immediately adjacent the roll bite on the entry side. Some of this build-up of liquid runs off on both sides of the strip and finds its way on to 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.

An object of the present invention is to provide a method of, and apparatus for, reducing the amount of lubricant on the strip at the exit side of the mill, thereby reducing unwanted staining of the surfaces of the strip.

According to a first aspect of the present invention, for use in a rolling mill for cold rolling metal strip, and where liquid lubricant is applied to the rolls, apparatus comprises a strip entry guide arranged for mounting at the entry side of the mill such that air pressure means on the entry guide extend transversely of the direction of movement of the strip through the mill and overlie the edge portions of the strip adjacent the roll gap, the air pressure means being arranged to direct liquid lubricant on the upper surface of the strip away from the gap and towards the centre of the strip.

According to a second aspect of the present invention, for use in a rolling mill for cold rolling metal strip, and where liquid lubricant is applied to the rolls, apparatus comprises a strip exit guide arranged for mounting at the exit side of the mill, such that air pressure means on the exit guide extend transversely of the direction of movement of the strip through the mill and overlie the edge portions of the strip adjacent the roll gap, the air pressure means being arranged to direct liquid lubricant on the upper surface of the strip outwardly towards the edges of the strip.

In order that the invention may be more readily understood, it will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic view showing in exaggerated form a strip between the work rolls; Figure 2 is a schematic, elevational view of a four-high roll stand employing the present invention, Figure 3 is an elevational partly cross-sectional view of a strip entry guide incorporating the present invention on the entry side of the stand; Figure 4 is a view of the top portion of the strip entry guide taken along line 4-4 of Figure 3; FigureS is an elevational partly sectional view of a strip delivery guide on the delivery side of the stand incorporating the present invention; Figure 6 is a partial plan view of the top portion of the strip delivery guide taken along line 6-6 of Figure 5;; Figure 7 is an elevational partly sectional view taken along line 7-7 of FigureS; Figure 8 is an elevational partly sectional view of the bottom portion of the strip delivery guide including a longitudinal frame; Figure 9 is a sectional view of the bottom portion of the strip deliver guide taken along line 9-9 of Figure 8; and Figure 10 is a partly sectional elevational view taken along line 10-10 of Figure 8.

Figure 1 illustrates the basic problem of a build-up 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 world rolls WR. 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 lubricant to flow down alongside the edges of the strip to make its way into field F and on to the delivery side of the mill.

Figures 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 travel of the strip.

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 Figures 2 through 10, in describing the present invention, Figure 2 will be referred to first. A roll stand 14 of a cold rolling mill has two back-up rolls, 15, 18 supporting two work rolls 20,22 which form a roll bite through which an aluminium 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 a strip entry guide 24 and an exit guide 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 Figure 2 and Figure 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 of which is shown at 32 in Figure 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 aluminium, 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 pressurised 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 atomised lubricant escaping to the delivery side, due to the rotation of the rolls, and landing on the strip 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 strip entry guide 24. It consists of upper portion 36 and lower portion 38 between which the strip travels.

Both of these portions 36,38 consist of a member 40 extending the width between the housing posts 29.

At opposite ends of each member 40, adjacent the ends of the work rolls, there 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 (Figure 4). The length of each nozzle assembly 42 is such as to accommodate both the maximum and minimum width of strip to be rolled.

As can be seen in Figure 3, the nozzles 44 in the upper portion 36 extend in the form of openings entirely through member 42, whereas those of lower portion 38 extend a short distance downwardly on to the underside of member 42. The openings of nozzles 44 are angled in such a manner as to deliver positive air pressure in the direction towards the centre of the rolls and the strip. This direction is clearly indicated by the three converging lines extending from the nozzles 44 in Figure 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 centre of the strip and rolls so that the lubricant is caused to remain on top of the strip and on the work rolls.

Each member 40 has a number of air solenoid valves 46 at the opposite end to the nozzles. Figure 4 shows the air solenoid valves 46 which are connected to one or more drilled longitudinal channels which, in turn communicate with two of the nozzles 44. As seen in Figure 4, the nozzles located on the extreme ends of the nozzle assembly member 42 are interconnected to longitudinal channels 48 through traverse channels 50.

The member 40 of the upper portion 36 is bolted to each side of the bridle assembly 28 by way of a bracket 50. For simplification, only one end of member 40 is shown, but it is to be understood that the other end of the member 40 is symmetrical about the centre-line 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 regulated to deliver positive air pressure and which valves are actually used depends upon the width of the 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 outer ends of the work rolls and strip will be operated, even though a minimum length of gap exists, because it is still desirable to prevent lubricant from leaving the ends of the two work rotl bodies and to avoid the strip nozzles 44 from removing too much lubricant off 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 94 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 the direction toward the centre of the rolls and, in the case of the upper nozzle assembly 42, towards the centre of the strip. 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 rolling 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 circumstances, permit lubricant to pass betwen the work rolls on to 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 centre 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 exit guide 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 approximately along the centre-line of the strip, and it is to be understood that the delivery strip guiding system is symmetrical about this centre-line.

A general overall design of the strip delivery guiding means of the present invention is shown in Figure 5. It consists of an upper and a lower portion 56, 58, respectively, which portions guide the strip passing through the rolling area on to the delivery side.

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 60,61 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 assemby 64 does not entirely extend to the centre-line 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 (Figure 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 Figure 6.

In addition to nozzle assemblies 68,70, member 62 has welded thereon three enclosures 82, 84, 86, separated by nozzle assemblies 68 and 70. As seen in Figure 6, each nozzle assembly 68,70 is a unit and is mounted on a member 61 by suitable means (not shown) and can be removed and replaced as such in the space provided between these three enclosures.

in viewing Figure 5, it can be seen that the enclosures 82,84 each have an opening 88 along the underside of the top portion 56 directly above the passline of the strip. In Figure 6, these openings 88 can be seen to be in the form of slots arranged in end-to-end relation and extending in the direction towards the centre of the strip. Each slot 88 extends the distance occupied 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.

Figure 6 indicates that nozzle header assemblies 68 and 70 and enclosures 82 and 84 slant inwardly from right to left toward the centre-line of the strip.

Using this centre-line as a focal point, the nozzle assemblies and the enclosures on the other side of member 62 would run outwardly from rightto 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 Figure 6. In an overail 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 centre 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 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 later. Nozzle assembly 70 co-operates with vacuum enclosure 82 and nozzle assembly 68 co-operates 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 membr 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 Figure 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), member 62 can be pivoted relative to member 60. For simplicity, this movement is not shown in phantom in any of the Figures 5,6 or 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 assemblies 112 located on both sides of top portion 56 (only one pistoncylinder assembly 112 is shown in Figure 6). This piston-cylinder assembly 112 is mounted by bracket 1 14to 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 equalisershaft 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 Figure 5, slide 98 runs at an angle relative to the mill passline.Through the operation of pistoncylinder assembly 114, top portion 56 moves upwardly in slide 98 in a horizontal position, as seen in Figure 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 ofthevaccum enclosures 130,132.

Similar two 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 the edges of the strip where it is drawn downwardly away from the passline. 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 phantom in Figure 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 and 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 later.

Movement of the lower portion 58 away from the rolling area is initiated through a linkage pistoncylinder assembly similar to that described for the top portion 56.

Figure 10 shows a half portion of the section taken along 10-10 of Figure 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 equaliser 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 phantom in Figure 8.

The precise location of rectangular box 148 relative to the edge of the strip is shown in Figures 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 of Figure 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. Transverse 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 the 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 widths of strip being rolled to cause the lubricant along the strip's edges to be forced into the vacumm chambers 148.

Each of the groups of nozzles in the nozzle assemblies 68, 70, 124 and 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 centre-line 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 strips. 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 the enclosure system 130, 132 of the lower portion 58, positive air against the undersurface of the strip loosens and forces the lubricant towards the edges of the strip. Enclosure 130 co-operates with nozzle assembly 124 and enclosure 132 cooperates with the nozzles of nozzle assembly 126 to draw most of the lubricant off the under surface of the strip. Any lubricant escaping along the edges of the strip on both its top and bottom surface is drawn into the rectangular vacuum chambers 148 and carried away from the strip area by means, not shown.

The inter-relationship and operation of all components of the present invention provides for the optimisation of the removal of lubricant away from the rolling area, particularly on the entry side and surfaces of the strip on the delivery side of a stand.

Claims (21)

1. For use in a rolling mill for cold rolling metal strip, and where liquid lubricant is applied to the rolls, apparatus comprising a strip entry guide arranged for mounting at the entry side of the mill such that air pressure means on the entry guide extend transversely of the direction of movement of the strip through the mill and overlie the edge portions of the strip adjacent the roll gap, the air pressure means being arranged to direct liquid lubricant on the upper surface of the strip away from the gap and towards the centre of the strip.

2. Apparatus as claimed in claim 1, wherein the strip entry guide includes upper and lower portions located above and below the strip passline, respectively, and the portions include air pressure means arranged to direct air against the strip contacting rolls to direct lubricant on the rolls away from the roll gap and towards the centre of the strip.

3. Apparatus as claimed in claim 1 or 2, including a bridle movable parallel to said passline towards and away from the mill and means for securing said entry guide to the bridle for movement therewith.

4. Apparatus as claimed in claim 1,2 or 3, wherein said air pressure means on said entry guide comprises a series of groups of nozzles delivering positive air pressure and means for delivering said positive air pressure to the nozzles.

5. Apparatus as claimed in claim 4, wherein said means for delivering said positive air pressure on the entry guide includes means mounted on the upper and lower portions of the entry guide for selectively controlling each group of nozzles according to the width of strip being rolled.

6. Apparatus as claimed in claim 5, wherein said means for selectively controlling each group of nozzles includes air solenoid valves.

7. For use in rolling mill for cold rolling metal strip, and where liquid lubricant is applied to the rolls, apparatus comprising a strip exit guide arranged for mounting at the exit side of the mill, such that air pressure means on the exit guide extend transversely of the direction of movement of the strip through the mill and overlie the edge portions of the strip adjacent the roll gap, the air pressure means being arranged to direct liquid lubricant on the upper surface of the strip outwardly towards the edges of the strip.

8. Apparatus as claimed in claim 7, wherein said strip exit guide consists of upper and lower portions located above and below the passline, respectively, and wherein said air pressure means is mounted in said upper portion.

9. Apparatus as claimed in claim 8, wherein each portion of the strip exit guide has positive and negative air pressure means arranged across the width of the strip and constructed so that the positive air pressure means loosens lubricant and the negative air pressure means draws said loosened lubricant off the top and bottom surfaces of the strip.

10. Apparatus as claimed in claim 9, wherein said positive air pressure means consists of at least two rows of nozzles arranged transversely across the width of the strip and the negative air pressure means consists of a vacuum chamber adjacent to each of said row of nozzles, said rows of nozzles and said vacuum chambers forming a chevron configuration across the width of the strip.

11. Apparatus as claimed in claim 10, wherein said rows of nozzles are grouped and positive air in each group is selectively controlled to be delivered to each group according to the width of the strip being rolled.

12. Apparatus as claimed in claim 11, comprising separate power means connected to said upper and lower portions of the strip exit guide for moving said upper and lower portions towards and away from the rolls and said upper portion towards and away from the passline and separate means mounted on the mill for guiding the upper and lower portions.

13. Apparatus as claimed in any of claims 7 to 12, including air pressure means located on the exit side of the mill alongside the edges of the strip for applying a negative air pressure to remove the lubricant thereon.

14. Apparatus as claimed in claim 13, including means for transversely adjusting said negative air pressure means according to the width of the strip being rolled so that said negative air pressure means is located in the vicinity of the edges of the strip.

15. Apparatus as claimed in claim 14, wherein said negative air pressure means are constructed and arranged to extend into the roll gap.

16. A rolling mill for cold rolling metal strip, and having provision for applying liquid lubricanttothe rolls, and having an entry guide as claimed in any of the claims 1 to 6, and an exit guide as claimed in any of the claims 7 to 15.

17. A method operating a rolling mill to cold roll metal strip in which liquid lubricant is applied to the rolls and air under pressure is applied to the upper surface of the strip on the entry side of the mill to direct liquid lubricant on the upper surface of the strip on the entry side of the mill away from the roll gap and towards the centre of the strip.

18. A method as claimed in claim 17, in which air is applied to the upper surface of the strip on the exit side of the mill to direct liquid lubricant on the upper surface of the strip outwardly towards the edges of the strip.

19. A method as claimed in claim 18, in which air is applied above and below the strip on the exit side of the mill and negative pressure conditions are created above and below the strip across substantially the entire surface of the strip to remove liquid lubricant from the surface of the strip.

20. Apparatus for usejn a rolling mill for cold rolling metal strip, where liquid lubricant is applied to the rolls, said apparatus being substantially as hereinbefore described with reference to the accompanying drawings.

21. A method of operating a rolling mill substantially as hereinbefore described with reference to the accompanying drawings.