US3760999A

US3760999A - Apparatus for guiding sheet

Info

Publication number: US3760999A
Application number: US00311557A
Authority: US
Inventors: Sandman K Hamilton
Original assignee: British Iron and Steel Research Association BISRA
Current assignee: British Iron and Steel Research Association BISRA
Priority date: 1971-12-03
Filing date: 1972-12-04
Publication date: 1973-09-25
Anticipated expiration: 1990-09-25
Also published as: GB1359027A

Abstract

An apparatus for guiding magnetisable metal sheet or strip in a processing line. A set of rollers are mounted with their longitudinal axes inclined at a small angle to the normal to the direction of movement of the sheet so that sheet contacting the rollers will be given a lateral component of movement in one sense. The stator parts of a series of linear induction motors are mounted between the rollers so that when energised they apply a lateral force to the sheet in the same sense. In operation the sheet is also attracted towards the stator parts of the linear induction motors and hence towards the rollers, and the angled rollers are thereby utilised to assist the electromagnetic steering force on the sheet.

Description

Sandman [451 Sept. 25, 1973 l l APPARATUS FOR GUlDlNG SHEET Keith Hamilton Sandman, Horsell, Woking, Surrey, England [73] Assignee: The British Iron and Steel Research Association, London, England [75] Inventor:

[22] Filed: Dec. 4, 1972 [2U Appl. No.: 311,557

[30] Foreign Application Priority Data Dec. 3, 1971 Great Britain 56,287/71 [52] US. Cl 226/15, 226/93, 27l/63 A [51] Int. Cl B65h 17/18 [58] Field of Search 226/93, 94, 3, 15;

[56] 7 References Cited UNITED STATES PATENTS 2,228,913 l/l94l Martin 27l/63 A 2,750,l87 6/1956 Bannister 226/93 X Primary Examiner-Richard A. Schacher Attorney-Leo A. Rosetta et a].

[ 57] ABSTRACT An apparatus for guiding magnetisable metal sheet or strip in a processing line. A set of rollers are mounted with their longitudinal axes inclined at a small angle to the normal to the direction of movement of the sheet so that sheet contacting the rollers will be given a lateralcomponent of movement in one sense. The stator parts of a series of linear induction motors are mounted between the rollers so that when energised they apply a lateral force to the sheet in the same sense. In operation the sheet is also attracted towards the stator parts of the linear induction motors and hence towards the rollers, and the angled rollers are thereby utilised to assist the electromagnetic steering force on the sheet.

10 Claims, 7 Drawing Figures PATENTEI] SEP2 5 I975 SHEET 1 [IF 3 saw 2 BF APPARATUS FOR GUIDING SHEET Guiding and steering metal sheet during its produc- 9 tion in process lines and mills is at present done by one of three methods. The simplest method is by side guides, either static or moving, which bear against both edges of the sheet and so keep it on course. The second method is to use self-centering rolls, i.e., rolls with convex-contoured bodies which effect lateral correction by creating tensile distortions in the strip. Thus with a crowned roll, if the sheet deviates from the central position, the crown creates a lateral tensile distortion in the strip resulting in it becoming cambered such that the materialis returned towards the centre of the roll in aligning itself perpendicular to the roll axis. The third method involves movable rolls.

There are problems associated with all these known methods and an object of this invention is to provide a simple means of guiding magnetisable metal sheet.

According to the present invention there is provided apparatus for guiding elongate sheet of magnetisable metal in a predetermined direction of movement including a first series of rollers along which sheet is advanceable in said predetermined direction, the longitudinal axes of the rollers being inclined to the normal to said direction so that sheet contacting said first series of rollers will be given a lateral component of movelatter arrangement the plane tangent to the rollers of the first series is preferably slightly inclined to the plane 7 tangent to the rollers of the second series so that when ment in a first sense, and a linear induction motor primary member disposed relative to said rollers so that when the primary member is energised, a lateral force is said first sense is applied to the sheet being advanced and the sheet is attracted to contact rollers of the first series.

Linear induction motors are known for providing linear electromagnetic forces. The induction motor consists of a primary member carrying windings to be energised with polyphase electric current, and a secondary member which can simply be a sheet of metal. One of the problems usually associated with linear induction motors is that the attractive force between the primary member and a secondarymember of magnetisable material is greater than the electromagnetic forces tending to cause the sheet to move across the face of the primary member. By contrast the present invention uses the attractive force to supplement the lateral electromagnetic forces on the sheet.

It is possible for the sheet to be prevented from moving laterally in the opposite sense to said first sense by a fixed guide. Preferably, however, the apparatus includes a second series of rollers along which sheet is advanceable in said direction, the axes of the rollers of the second series being slightly inclined to the axes of the rollers of the first series so that sheet contacting said second series of rollers will be given a lateral component of movement'in the opposite sense to said first sense, and a second linear induction motor primary. member disposed so that when it is energised a lateral force in said oppositesense is applied to the sheet being advanced and the sheet is attracted to contact rollers of said second series.

In one possible arrangement the first and second'series of rollers are spaced so that in use the sheet passes between them. The spacing between the first and second series may be adjustable to accommodate sheet of difierent thicknesses. In another possible arrangement the first and second series of rollers are disposed side by side to contact the same surface of the sheet. In the a sheet is attracted into contact with one series of rollers it is out of contact with the other series of rollers. The apparatus preferably includes a sensor to sense the lateral position of a sheet, and control means to control the primary members in response to a signal from the sensor. There could be sensors at each edge of the sheet in order to sense the position of the centre of the sheet.

In the accompanying drawings:

FIG. 1 shows a side view of one apparatus according to the invention in use on a horizontal sheet storage loop,

FIG. 2 is a plan view, partly cut away, of a part of the apparatus of FIG. 1,

FIG. 3-shows a plan view of a second apparatus according to the invention,

FIG. 4 is a side view of the apparatus of FIG. 3.

' FIG. 5 shows a plan view of a third apparatus according to the invention, and

FIGS. 6 and 7 are side and end views respectively of the apparatus of FIG. 5.

In many processes where sheet steel is handled a storage loop defining a path along which sheet is advanced is provided to enable the process to continue while the beginning of a new coil is welded to the end of the sheet already being processed. The apparatus of the storage loop for sheet steel 2 shown in FIG. 1 includes a first and

second roll

4 and 6 and a roll 8 mounted on a wheeled carriage 10 which is biased by a spring 12 so as to take up any slack in the sheet 2. The sheet is guided laterally by guiding apparatus mounted on a wheeled carriage 14 connected by a link 16 to the carriage 10. It is to be understood that guiding apparatus could be mounted on an enlarged carriage 10 instead of having a separate carriage 14.

The guiding apparatus includes a first series of rollers 18, a second series of rollers 20, a number of linear induction motor primary members 22 arranged to cooperate with the rollers 18 and a second set of primary members 24 arranged to cooperate with the rollers 20. The rollers 18 are mounted in bearings 26 and the rollers 20 in bearings 28 connected to the carriage 14 so that the sheet 2 passes between the two series of rollers. The axes of the rollers 18 are slightly inclined to the axes of the rollers 20 so that if the sheet 2 is in contact with the rollers 18 it will be given a lateral component of movement in one sense as it is advanced in the direction of the arrow p and if the sheet 2' is in contact with the rollers 20 it will be given a lateral component of movement in the opposite sense. Each series of rollers isinclined at an angle of less than three degrees'to the normalfto the direction of movement P" of the sheet There is a

primary member

22, 24 parallel to and between adjacent pairs of

rollers

18, 20 in each series of rollers. The primary members 22 are wound so that when energised a lateral force is applied to the sheet 2 in the same sense as the force is applied by the inclination of the rollers 18. The primary members 24 are wound to apply a lateral force to the sheet 2 in the opposite sense.

A sensor 30 is disposed adjacent to one edge of the sheet 2 to sense its position. A signal from the sensor 30 is fed to a comparator 32 which compares the signal with a signal 34 indicating the desired sheet position. A signal is then fed from the comparator 32 to a variable voltage or variable power controller 36 which controls the supply to the

primary members

22, 24.

When the sensor 30 senses that the sheet 2 hasdeviated laterally from its desired position, for example upwardly in FIG. 2, the controller 36 energises the primary members 22 which apply a lateral force to the sheet 2 tending to deflect the sheet back towards its desired position. Simultaneously the primary members 22 atrract the sheet 2 into contact with the series of rollers 18 which therefore also deflect the sheet 2 in the same sense. The primary members 24 can remain unenergised or alternatively they can be energised with the windings reversed'so as to provide a lateral force to supplement that of the primary members 22.

If the windings 24 are energised they must either be supplied with less power than the primary member 22 so that the sheet 2 is attracted more strongly to the rollers 18, or they can be energised slightly after the primary members 22 so that the strip once attracted to the rollers 18 would remain in contact with them.

In the arrangement shown in FIGS. 3 and 4 a first and second series of

rollers

50, 52 are spaced so that the sheet 2 passes between them as in FIG. 2. The arrangement differs from FIG. 2 in that the rollers 50 are mounted in a first frame 54 and the rollers 52 are mounted in a second frame 56, the two

frames

54 and 56 being movable relative to one another. The frame 54 is supported on the frame 56 by springs 58 which urge the frame 54 away from the frame 56. A stop 60 limits upward movement of the frame 54. Pairs of rolls 62 are located at the front and rear ends of the

frames

54, 56. The rolls 62 are mounted in housings 66 pivoted at 68 to the

frames

54, 56 in such a manner that the rolls 62 are behind the pivots 68 and therefore the rolls 62 cannot exert a mistracking force on the strip 2 moving in the direction of the arrow.

Two series of linear motor primary members 70 are disposed between the rollers 50 52 as in the arrangement of FIG. 2. When either series of primary members 70 are energised the upper frame 54 will move towards the frame 56 under the attractive force of the primary members 70 and will overcome the force in the springs 58. The rolls 62 space the

frames

54, 56 apart by a distance which takes account of the thickness of the strip 2. Thus when very thin strip 2 is being processed the gap between the upper and lower units is automatically reduced so as to obtain maximum thrust from the primary members 70.

As in FIG. 2 a sensor 30, comparator 32 and controller 36 are provided for controlling the primary members 70. In addition one of the rollers 50 and one of the rollers 52 are each provided with a load cell (not shown) to indicate which set of rollers the sheet 2 is in contact with. The load cells control the power to each set of primary members 70 so that the sheet is in contact with the appropriate set of rollers to steer the sheet in the right direction.

In the arrangement shown in FIGS. 5 to 7 a first and second series of

rollers

40, 42 are disposed side by side to contact the under surface of the sheet 2. The axes of the

roller

40 and 42 are slightly inclined to one another so that each series tends to deflect the sheet 2 moving in the direction of the arrow P" towards the other series. There is a linear motor primary member 44 between each adjacent pair of rollers 40 and a primary member 46 between each adjacent pair of rollers 42. The

primary members

44, 46 are mounted on supports 48. As can be seen in FIG. 7 the plane tangent to the rollers 40 of the first series is slightly inclined to the plane tangent to the rollers 42 of the second series. A sensor 30, comparator 32 and controller 36 are provided similar to those in FIG. 2.

When the sheet 2 deviates laterally from its desired position the appropriate

primary members

44 or 46 are energised. The attractive force that attracts the sheet into contact with one series of

rollers

40 or 42 lifts the sheet out of contact with the other series of

rollers

42 or 40 respectively as can be seen in FIG. 7. The rollers therefore apply a lateral force to the sheet to supplement the lateral force of the primary members.

In process lines where the surface finish of the sheet is important the rollers can be covered with a material such as rubber or polyurethane.

The invention provides a simple guiding device for magnetisable sheet metal by means of linear induction motors in which the attractive force is utilised to assist the electromagnetic steering force.

We claim:

1. Apparatus for guiding elongate sheet of magnetisable metal in a predetermined direction of movement including a first series of rollers along which sheet is advancable in said predetermined direction, the longitudinal axes of the rollers being inclined to the normal to said direction so that sheet contacting said first series of rollers will be given a lateral component of movement in a first sense, and a linear induction motor primary member disposed relative to said rollers so that when the primary member is energised, a lateral force in said first sense is applied to the sheet being advanced and the sheet is attracted to contact the rollers of the first series.

2. Apparatus according to claim 1 including a second series of rollers along which sheet is advancable in said direction, the axes of the rollers of the second series being slightly inclined to the axes of the rollers of the first series so that sheet contacting said second series of rollers will be given a lateral component of movement in the opposite sense to said first sense, and a second linear induction motor primary member disposed relative to said second series of rollers so that when the second primary member is energised, a lateral force in said opposite sense is applied to the sheet being advanced and the sheet is attracted to contact rollers of said second series.

3. Apparatus according to claim 2 in which the first and second series of rollers are spaced so that in use the sheet passes between them.

4. Apparatus according to claim 3 which the spacing between the first and second series of rollers is adjustable to accommodate sheet of different thicknesses.

5. Apparatus according to claim 2 in which the first and second series of rollers are disposed side by side to contact the same surface of the sheet.

6. Apparatus according to claim 5 in which the plane tangent to the rollers of the first series is slightly inclined to the plane tangent to the rollers of the second series so that when a sheet is attracted into contact with one series of rollers it is out of contact with the other seriesof rollers.

7. Apparatus according to claim 1 in which a number of primary members are arranged to cooperate with the series of rollers to apply lateral forces to the sheet.

6 8. Apparatus according to claim 7 in which primary 10. Apparatus according to claim 1 including a senmembers are disposed between adjacent pairs of roll-- sor to sense the lateral position of a sheet, and control ers. means to control the primary member or members in 9. Apparatus according to claim I mounted on a response to a signal from the sensor means. wheeled carriage. 5

Claims

6. Apparatus according to claim 5 in which the plane tangent to the rollers of the first series is slightly inclined to the plane tangent to the rollers of the second series so that when a sheet is attracted into contact with one series of rollers it is out of contact with the other series of rollers.

8. Apparatus according to claim 7 in which primary members are disposed between adjacent pairs of rollers.

9. Apparatus according to claim 1 mounted on a wheeled carriage.

10. Apparatus according to claim 1 including a sensor to sense the lateral position of a sheet, and control means to control the primary member or members in response to a signal from the sensor means.