US3627665A

US3627665A - Apparatus for the production of flat metal sheets, particularly tin plate sheets

Info

Publication number: US3627665A
Application number: US620528A
Authority: US
Inventors: Willy Charles De Laminne
Original assignee: Cockerill SA
Current assignee: Cockerill SA
Priority date: 1967-03-03
Filing date: 1967-03-03
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

An apparatus for the continuous production of tin plate sheet metal including a spool of sheet metal, an unrolling device carrying the spool, a strip of sheet from the spool, a driving device advancing the strip, a welding device, an accumulator for the strip, a tensioning device composed of a braking means and a traction means for maintaining the strip taut during its passage in the apparatus, a degreasing device, a pickling device, rinsing vats, an electric tinning device, for applying a tin coating on the strip, a drying device, a rollers smoothing device into which the strip of metal sheet passes, a re-fusing device of the tin coating, a hole detector and a guillotine for cutting the strip.

Description

mam States mm [72] Inventor Willy Charles de Laminne Liege, Belgium [21] Appl, No. 620,528

[22] Filed Mar. 3, 1967 [45] Patented Dec. 14, 1971 [73] Assignee Cockerill-Ougree-Providence et Esperance- Longdor en abrege Cockerlll" Seraing-lez-Liege, Belgium [54] APPARATUS FOR THE PRODUCTION OF FLAT METAL SHEETS, PARTICULARLY TIN PLATE SHEETS 1 Claim, 2 Drawing Figs.

[52] U.S. Cl 2041/209, 204/210 [51} lnt.Cl B0lr 3/00, C23g 5/68 [50] Field of Search 204/209,

[56] References Cited UNITED STATES PATENTS l,5l7,910 12/1924 Kirschneru 204/210 2,240,265 4/1941 Nachtman 204/210 X 2,439,858 4/1948 Muddiman et al 204/209 FOREIGN PATENTS 576,313 3/1946 Great Britain 204/209 OTHER REFERENCES Stoltz et al., The Electrochemical Society, Preprint 84-26, pages 283, 285, 290 are relied on Primary Examiner.lohn H. Mack Assistant ExaminerR. J. Fay Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT: An apparatus for the continuous production of tin plate sheet metal including a spool of sheet metal, an unrolling device carrying the spool, a strip of sheet from the spool, a driving device advancing the strip, a welding device, an accumulator for the strip, a tensioning device composed of a braking means and a traction means for maintaining the strip taut during its passage in the apparatus, a degreasing device, a pickling device, rinsing vats, an electric tinning device, for applying a tin coating on the strip, a drying device, a rollers smoothing device into which the strip of metal sheet passes, a re-fusing device of the tin coating, a hole detector and a guillotine for cutting the strip.

I 1 19a. 49 49b PATENTEU DEC 1 4 an SHEET 1 or 2 PATENTED DEC] 412m SHEET 2 OF 2 APPARATUS FOR THE PRODUCTION OF FLAT METAL SHEETS, PARTICULARLY TEN PLATE SHEETS This invention relates to apparatus for the production of flat metal sheets, particularly tin plate sheets.

It is known that in general, thin metal sheets or strips are manufactured from a metal ingot which is subjected to several hot or cold rolling operations, possibly preceded and/or followed by other operations, such as annealing, pickling and tinning, depending on the intended final use of the metal sheet.

In spite of the perfection of the machines used and in spite of all the care taken in the carrying out of the operation, the production of perfectly flat metal sheets required for certain uses always constitutes a problem which has not previously had a satisfactory solution.

Generally, the metal sheets still have faults which affect their flatness and which can be classed according to two principal groups. First of all certain faults are constituted by portions of geometrically developable surfaces and are due to a difi'erence of uniform length between the grains of each of the faces of the metal sheet; in this category are classed mainly the defects appearing in the form of a general bending in the length or in the width. Consequently, certain defects which result from an unequal distribution of material are constituted by portions of geometrically nondevelopable surfaces; among these are the ribbing along the edges or at the center projections or aligned hollows or more or less apparent ribbings, often disposed in a fishbone arrangement. Whatever their nature or position in the sheet metal, these defects are annoying, not because of their effect on the appearance of the sheet, but also because of their bad influence on the final use of the metal sheet for the fabrication of certain articles requiring an absolutely flat metal sheet. in all ways the defects reduce the quality of the metal sheet and occasionally reduce the selling price. This has led to investigations being made to eliminate these defects in flatness of metal sheets.

For this purpose, metal sheets are often subjected to a smoothing operation which is generally carried in a roller smoothing device.

Such a rolling device comprises two series of motor driven working rollers whose axes are disposed in two planes forming a small angle between each other, the successive rollers of a series partly occupying the successive intervals of the rollers of the other series. The strip of sheet metal to be smoothed is engaged between the two series of rollers whose action is to impose on the strip a succession of alternate flexings according to the arcs of contact between the strip and the rollers; these flexings progressively diminish from the entrance to the smoothing device up to the exit and this effect is obtained by a suitable arrangement of the rollers. The efficacy depends on the number of rollers and on their diameter which does not generally exceed 200 times the thickness of the sheet metal.

In practice, this type of smoothing shows that its effectiveness if it is real to correct the developable faults is minimal as far as concerns the nondevelopable faults, since the correction of the latter requires the application of a tension to the strip during its passage in the smoothing device. The effects of the tensions are superimposed on those caused by the alternate flexings, and the combination of the traction and the alternate flexings result in imposing on the sheet metal a slight permanent extension necessary for the correction of the flatness.

But in this case it is necessary to avoid the sliding of the rollers on the sheet metal, and for this purpose the rollers must have a peripheral speed precisely adjusted to the speed of advancement of the sheet metal. Such adjustment is very difficult if not impossible to carry out simultaneously for all the rollers in view of the fact that the peripheral speed is identical for all the rollers since they are integral with the same drive motor and that the speed of the strip increases at each passing of a roller as a result of the elongation which it undergoes; the result of this is a difference of speed between the roller and the strip which is in many cases prejudicial to the good finish of the sheet metal.

This known smoothing has not yet been applied in a tin plate production line.

According to the present invention there is provided apparatus for the continuous production of tin plate sheet metal by electrolyte deposition of tin on a sheet metal which is unrolled from a spool and is maintained taut during the whole of its passage in the apparatus comprising a device for tensioning the strip mainly constituted by a traction means, a degreasing device, a pickling device, an electrolytic tinning device and a device for refusing the coat of tin, and a roller smoothing device in which the strip of sheet metal passes.

In accordance with one feature of the invention, the roller smoothing device is situated between the electrolytic tinning device and the device for refusion of the tin.

In accordance with a further feature of the invention, the smoothing rollers are idly mounted, that is to say are not provided with any drive means.

The invention also provides apparatus for the continuous production of flat sheet metal by passing between the smoothing rollers a strip of sheet metal unrolled from a spool kept taut for all of its passage between the smoothing rollers and specially of a strip of sheet metal having undergone known cold working rolling under the name of skin-pass" characterized in that the said smoothing rollers are idly mounted.

The invention will now be described in greater detail by way of example with reference to the accompanying drawings in which:

FIG. 1 shows a diagrammatic view of apparatus for the continuous production of tin plate in accordance with the invention, and

FIG. 2 is a diagrammatic view on a larger scale of the smoothing device with idle rollers.

The apparatus for the production of tin plate by electrolytic deposition of tin comprises an unrolling device 1 carrying a spool of sheet metal 2 unrolling in the form of strip 3 which is advanced in the direction of the arrows X by means of a driving device 4 placed after a welding device 5; the strip then arrives in a depression 6 forming an accumulator where it comprises a loop 30. At the exit of the depression 6 the strip passes into a braking means 7, comprising the first part of a tensioning device, the second part of which comprises traction means 8 situated towards the end of the line.

After the braking means 7, the strip travels through a series of known devices mainly consisting of a hole detector 9, a thickness gauge 10, degreasing, rinsing and pickling vats 11, a brushing vat l2, electrolytic, tinning and rinsing vats l3, and a drying device 16. At the exit, the tinned strip 3 travels across a smoothing device 14, a device for the refusion of the tin l5 and the traction means 8; then it passes through a hole detector 21 and forms a loop 3b before arriving at a guillotine 17 which cuts it into sheets of given length which then undergo other treatments before storage.

The roller smoothing device 14 (FIG. 2) comprises two series of

idle roller

18 and 19, that is to say rollers not driven. The spindles of the idle rollers 18 turn in bearings 18a all fixed to a stringer 18b integral with the frame 20, and the spindles of the idle rollers 19 turn in bearings 19a fixed to a stringer 19b also integral with the frame 20. Since the planes containing the axes of the

idle rollers

18 and 19 respectively make between each other a very small angle, the strip 3 which travels in the direction of the arrow X under the action of traction makes the idle rollers turn. At the entrance into the device the strip undergoes a more pronounced flexing than at the exit.

At smoothing device such as that just described is advantageous since it does not have any complex controls as the known smoothing devices and it is not necessary to provide a system for regulating the speed of the rollers according to the linear speed of the strip; the device is also less difficult to run and costs less than a smoother with motor driven rollers.

Furthermore, it has been estimated that the device is able to remove even the nondevelopable faults and that there is no danger of a rupture of the strip in the course of operation because of the low inertia of the rollers; furthermore contrary to a currently spread opinion, the effects of smoothing are not decreased by high advancement speeds of the strip, so that a smoothing device in accordance with the invention can be atrained which can exceed a speed of 250 meters per minute.

What I claim is:

1. An apparatus for the continuous production of perfectly plane tin plate sheet metal comprising a spool for strip sheet metal, an unrolling device carrying said spool, a driving device advancing said strip, a welding device, an accumulator for said strip, a tensioning device composed of a braking means and a traction means for maintaining said strip taut during its passing in the apparatus, a degreasing device, a pickling device, rinsing vats, an electrolytic tinning device for applying a tin coating to said strip, a drying device, a rollers leveler consisting of idly mounted rollers horizontally disposed in two sets, one above the other, in a staggered relationship to each other, each of said rollers being of substantially the same diameter, and between which said strip of sheet metal travels under traction and undergoes alternate flexing so as to correct the flatness of said strip under traction, a reflowing device for said tin coating, a hole detector, and a shear for cutting said strip, said rollers leveler being located between said electrolytic tinning device and said reflowing device for said coating,

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