US2087010A

US2087010A - Method and apparatus for preventing coil breaks in sheet metal

Info

Publication number: US2087010A
Application number: US732544A
Authority: US
Inventors: Ambrose J Wardle; Harvey D Miller
Original assignee: McKay Machine Co
Current assignee: McKay Machine Co
Priority date: 1934-06-26
Filing date: 1934-06-26
Publication date: 1937-07-13
Anticipated expiration: 1954-07-13

Description

July 13, 1937. A. J. WARDLE ET AL v 2,087,010

METHOD AND lAPPARATUS FOR PREVENTING COIL BREAKS IN SHEET METAL- Filed June 26, 1934 2`Sheets-Sheet l Il H up. v0 90 gmc/whom Amfasfd MEME July 13, M937. A. J. WARDLE ET A1. 0879010 MET-HOD ANDAPPARATUS FOR PREVENTING CGIL BREAKS IN SHEET METAL v Filed .June ze, 1954 2 sheets-shea 2 Patented July -1,3., 1937 FATENT OFFICE METHOD AND APPARATUS FOR PREVENT- ING COIL BREAK Ambrosel J. Wardle aid S N SHEET METAL Harvey D. Miller, Youngstown, O hio, assignors to The McKay Machine, Com-pany, Youngstown, Ohio, a corporation of Ohio. l ApplicationA June 26.

V 16 Claims.

i This invention relates to a method and apparatus for preventing coilbreaks inrstrlp sheet metal, and is a continuation in part of our application Seal No. 507,506,l filed January 8,

It is the present practice' to coil so-called strip sheet metal as it passes from the hot rolls, and the successive coils are taken from the rollsand permitted to cool. The gradual cooling of the coils causes the metal to become annealed to a certain extent, and when` the metal is subknown in the tradeas coil breaks. Trie uncoiling or unwinding of the coils usually is accomplished merely by loosely arranging the coil in an enclosure commonly termeda coil box, and

pulling the free end of the strip. The metal, as it progressively unwinds, tends to retain its curved shape due to the fact that the metal sets or assures the curved shape of the coil when cooling, and the pulling of the free end of the strip from the coil causes the coil breaks referred to.

The occurrence of coil breaks in strip sheet metal is of quite serious consequence for several reasons.. In the first place, the coil breaks cannot be completely removed from the metal by any known method, and the subsequent forming of metal articles, as for example, by stamping ,0 or die-drawing, causes the imperfections of the coil break tov become `Vapparent in the surfaces of the metal. It is well known that these surface imperfections cannot be 4completely covered by surface coating compositions, and thus the value of the metal is materially reduced. Forexample, strip material containing coil breaks cannot -be satisfactorily .employed for cold rolling in the manufacture of automobile body sheets or of the highly finished die-drawing sheets. 40 Moreover, because o f the economy in manufacthat itsuse be extended to'wider sheets of metal than are usually included lin the term stripV metal. The extension of the ceiling practice to wider` sheets' has'been limited. however,` due to referred to and the impossibility of usingv sheets in which coil breaks occur injconnection with particular'classes of work.

moving coil breaks, and these methods, so far `Ilswe are aware have been o nly partially vsuc-l Y thiseonnection it will be noted that these methy ods now in use have been referred toas methvuodsiorremovinge'oilbreaks'.emisora:-aswe ture effected by coiling sheet metal, it is desirablel the difficulties` experienced with the coil breaks Numerous methods'have been proposed for re` 1934, Serial No. 132,544

are aware, no method ever has been devised whereby the creation of the coil breaks has been prevented.l l y in important'object of the present invention is to provide a method of uncoiling sheet` metal to prevent the creation of coil breaks, thus eliminating the necessity vfor attempting to remove the coil breaks, and rendering the strip suitable for use for making sheets and other articles which cannot now be satisfactorily made because of the presence of the coil breaks.`

A further objectlis to provide a method of uncoiling sheet metal so as to provide a flat sheet 'of metal Without any coil breaks therein, thus.

making it practicable to extend the practice of ceiling metal strip to relatively wide sheets.

A further object is to provide a method of uncoiling sheet metal by resisting the uncoiling of the metal and at the same time causing it to break around a reverse curve starting from the point at which the sheet leaves the coil to prevent the formation of' coil breaks in the metal.

A `further object is to provide a method of the character outlined wherein a pulling force is exerted upon the sheet as it is uncoiled while the uncoilin'g'action is resisted by a metal working member about which thesheet is caused to take apparatus wherein the placing of a coil of sheet' metal in operative position in the apparatus is facilitated, and wherein Vthe sheet, as it is un- 1 coiled, passes from the apparatus without the presence of coil breaks therein...`

A further object is `to provide ari-apparatus of the-character referred to wherein a sheet work-` the coil and is caused to exert a pressure .thereagainst to `resist the uncoillng of the strip, and to provide pulling means for uncoiling' the strip at such an angle with respect to the sheet working member as to cause the sheet to "break around the sheet working member in uniform contact therewith, due to the resistance to the uncoiling of the strip, thus preventing the forrnal tion of coil breaks in the strip as itis uncoiled.

Othenobjects and advantages of the invention willbeco'me apparent during the course of the following description.4

In the uncoiling of strip metal it is the common luneoil the metal by pulling the outer end of the strip from the coil without resisting the turning- `ing member is maintained in engagement with practice to support a coil on cradle rolls and to` movementl of the coil. Under such conditions, the strip, after it leaves the coil, tends to malnvtain the curvature of the coil, and the pulling force exerted in uncoiling the strip causes the well known breaks to occur at spaced intervals along the strip. It is this fault which has proved a seriousdiiiculty in extending the use of coiled strip metal. We have found that if the turning movement of the coil is resisted as the strip is uncoiled therefrom, the same tendency of the strip to maintain the curvature of the coil is present, but the breaks occur progressively closer as the resistance to the turning movement of the coil is increased. However,- it has been found that the breaks cannot be wholly eliminated merely by increasing the resistance to the turning movement of the coil, it being possible merely to cause the breaks to occur in close parallel lines, in which case the individual breaks are reduced so far as the grain structure of the metal is concerned without the elimination of the breaks.

We have further discovered that a sheet working member, such as a pinch roll, can be arranged against the surface of the coil and the free end of the strip pulled from the coil in such a manner as to cause the strip to tend to take a reverse curvature around the metal work- 'lng member. With such a method, the strip as it is uncoiled is not permitted to follow its tendency to retain the curvature of the coil, but is caused to tend to assume a reverse curvature starting from the point at which the strip leaves the coil. This method of uncoiling strip metal is highly advantageous provided the Aturning movement of the coil is substantially resisted to cause the strip to follow the curvature of the sheet working member or pressure roll.

In this connection, attention is invited to the fact that if a method such as that outlinedl is employed without substantial resistance to the turning movement of the coil, the strip as it is uncoiled will tend to follow the curvature of` the pressure roll but not to a sufiicient extent to cause the grain structure of the strip to be uniformly worked. In other words, the result of such action is to cause the breaking of the shet along parallel lines which move progressively closer together as the resistance to the turning movement of the coil is increased. A substantially different and vitally important result 'can be obtained,'however, as compared with the practice of merely resisting the 4turning movement of the coil without the use of the metal working member. In the latter case, the parallel lines along which the metal breaks can be brought progressively closer together as the resistance to the turning movement of the coil is increased,

' but a uniformity in the working of the sheet character referred to is employed, the increasing o f the resistance to the turning movement of the coil brings the lines in the coil break progressively closer together until the resistance to the turning movement reaches suchpoint as to cause the strip to hug the surface of the metal working member. At such point, the indlvidual lines of coil break in the sheet will whollydlsappear and a condition will be obtained ymeans may be employed for resisting the turning movement of the coil, the most advantageous method lies in the exertion of pressure against the coil by the metal working member employed. Accordingly the present method contemplates the use of a metal working member in the form of a pinch roll about which the metalI assumes a reverse curvature as it leaves the coil, while simultaneously resisting the turning movement of the coil preferably by exerting a pressure against the pinch roll to maintain it under pressure against the coil and thus grip the convolutions of the coil between the pinch roll' and the mandrel, to resist the turning movement of the coils This method of procedure, of course, can be varied, for example, by adding an adjustable brake to the pinch roll to variably resist the turning movement thereof.

The extent to which the strip is broken around the pinch roll is not critical, but it is preferred that it be carried out to a substantial extent. that highly advantageous results are obtained by breaking the strip around the pinch roll to an extent asaclose to degrees as possible, although even better results can b'e obtained if the strip is carried around the pinch roll degrees. The latter operation offerssubstantial difllculties from a practical standpoint, and it is preferred that the strip be carried -around the pinch roll to an extent approximating from 80 to 90 degrees because of the advantageous results obtained by such method in conjunction with the elimination of operating difficulties. We have also found this result advantageous for the reason that it carries the sheet as it leaves Ithe coil substantially away from a plane of tangency with the coil and thus reduces the transmission of a direct uncoiling movement to the coil as the sheet ,is pulled therefrom and renders the pressure of the pressure roll against the coil more effectiveA in resisting the turning movement of the latter.

From the foregoing, it will be apparent that instead of the usual practice of attempting to remove coil breaks from the strip after their formation therein, the present method contemplates the prevention of the formation of coil breaks as the sheet is unwound from the coil. In the subsequent processingv of the metal, therefore, as in the case of die-drawing, cold rolling For example, in practice, we have found' or the like, the development of lsurface or strucl tural imperfections due to incompletely removed coil breaks is wholly prevented.

In the drawings we =have shown one form o apparatus particularly adapted for practicing the method. In this showing:

Figure 1 is a transverse central vertical sectional view through the apparatus,

Figure 2 is a front elevation, parts being shown in section,

Figure 3 is a section on line 3-3 of Figure 2, the arbor being shown' in retracted position, and,

Figure 4 is a detailelevation of one of the brake devices. v

Referring to the drawings, the numeral Ill designates a pair of side frames as a whole, and

the forward end of each side frame extends upwardly as at II to form `a. standard. Each standard il is provided with a vertical slot i2 flanged as at uI3 to form a guideway. A cross-head Il extends between the side framesl and has lits ends projecting into the guideways I3 `as shown in Figure 2. Bearing blocks I are carried by the ends of the cross-head I4 and are slidable in the guideways I3.

Each block I5 carries a bearing I6 rotatably supporting the trunnions I1 of a back-up roller I8. A vertical shaft I9 is connected at its lower end to the cross-head I4 and is provided at its upper end with a piston 20 reciprocating in a cylinder 2 I. IThis cylinder is flanged at its lower end as at 22 and bolted as at 23 .to a support 24 mounted upon the upper ends of, the standards I0 and extending therebetween.

Below the back-up roller I8, a metal working member 25 is arranged, and this member is in the form of a pressure roller.' The ends of the roller 25 areimounted in bearings 26 slidable in y movementbetween these elements. The cylinderthe guideways I2. The ends of the roller 25 project beyond the side frame members and are provided at their ends with brake drums 21 surrounded-and engageable by a split brake-band 28. I'he free'ends of each brake band extend upwardly and are arranged on opposite sides of a lug 29 carriedbyeach end of the crosshead I4. A spring urges the ends of each brake Aband away from each other, and a bolt 3i is adapted to tighten each of the brake bands, as will be apparent. The brake devices may be ot 30 is mounted in each side frame to slidably and rotatably receive vthe arbor 34, and a substantially conical head 36 is carried by the free e nd of the arbor to facilitate its entrance into the y bearing v'35 at the side of the apparatus opposite .the supporting rollers 33. The arbor 34, while described as a single element, is preferably made lup of a series of rollers 34' arranged in end to* Vend relation, to permit a coil to shift itself more readily onthe arbor to compensate for distortion of the coil, as will become apparent.

v'Il'l'e rollers 34 of the arbor 34 are supported by ball or roller bearings' 31 in which is mounted a cylinder 38. Thefbearings 31 permit the arbor Y i to rotate about the cylinder. 38 while the bear- ,Y

ings and'their cages preventl relative longitudinal 38 is provided with a laterally extending linger 39 slidable ina guide slot 48 formed in .a guide., `rail 4I secured to the top oi one of the supports `32. A hollow piston rod 42 issecured at its Jouter end to a bracket 43 connected between and exi tendini above the supports 32. The piston rod 42 is arranged in-axial alinemerit with the cylinder 33 and extends thereinto through a stuiing box 44. The piston rod 42 communicates with the` interiorlof the cylinder and is provided at its inner end with a pistonv45 reciprocable in the Air for the operation of' the cylinders v2I and 3 8l andyassociated elements is derived from any suitable source of pressure.` In .Figure 2. a pipe 43 is illustrated as being connected at one end to i a conventional reducing valve 41, while the oppoplate 53 thereto.

site end of the pipe `46 is adapted to be connected to the source of air pressure. The reducing valve is employed in order that a desired predetermined pressure may be supplied to the cylinder 2 I. 'From the reducing valve, the pipe 48 leads to a manually operable control valve 49, and branch pipes 58 lead from the control valve to the ends of the cylinder 2|` in order that air pressure. may be 'introduced into either end or the cylinder'and exhausted from the opposite end. Air pressure is similarly utilized for operating' the cylinder 38. The reducing valve 41, or a similar valve, rnay be employed for supplying air-to the cylinder 38, and

- a manually controlled valve (not shown) controls the supply of fluid pressure from the reducing valve, or from the source of pressure to a pair of pipes 5I and 52. The pipe 5I communicates with the outer end of the piston rod 42 to supply 'uld pressure to the outer end oi.' the cylinder 38.'

'Ihe pipe 52 is in the form of a exible hose to permit reciprocation oi the-oylinder'38 to take place. The cylinder, however, is prevented from rotating during its reciprocation by the arrangement of the linger 39 in the guide slot 48.

Means are provided forplacing a coil of stripA or sheet metal in position in the apparatus. A plate 53 is arranged between the side plates I Il near the bottom thereof, and a shaft 54 extends.

between the side plates to pivotally connect vthe The plate 53 is provided with an arcuate depression 55 to receivev a coil 56 of strip or sheet metal. An adjustingymember 51 having an arcuate inner face is arranged over the plate 53, as shown in Figure l.' A screw 58 is connected to the adjusting member and passes through a'lug 59 carried by the, plate 53. The

member 51 is adjustable forwardly to assist in steadying the coil 55 on the plate 53 and to prop-v erly position the coil. The cross-head I4 is provided near opposite ends thereof with outstanding lugs 60 in which arearranged vertical rods 6I.

These rods are connected at their lower ends to' links 62, as at 63, and the lower endsof the links 62 are pivotally connected asat 64 vto opposite sides of theplate 53. Accordingly it will be a'pl -Parent that vertical movement of the cross-head I4 will be transmitted to the plate 53 to raiseand lower the` latter.

Rearwardly of the standard il, each.' side frame is provided with a vertical guide slot 18 in which are arranged upper and lower sets of bearings 1| and 12.' rIlhe upper bearing 1I ,rotatably supports rollers 13,.while a similar set oi' lower rollers 14 is journalled in the bearing 12. One of the sets oi rollers referred to -is positively driven by any suitable source of power to withdraw the sheet from the .-coil, and the sheet passes between the rollers 13 and 14 inthe manner shown in Figure 1.

Screws 16 are adapted to adjust the height of v'the lower rollers 14. These screws are threaded inthelower bearing blocks 12 and carry worm gears 11 at their lower ends meshing Withworms 18 carried by shafts 19. These shafts and the shafts of the screws 16 are journalledsin bearing members 88.

A threaded stenii is arrangecnover each bearing block 1I and is adapted toA be fed up/wardly and downwardly by a worm wheel 82 meshingY i with a worm 83 carried by a shaft 84., The stems 8| passthrough plates 85 at the "top of. the guide slot 18, and are provided at their lower ends with washers 86 contacting with the upper ends of springs 81. The lower ends of these springs bear against the bearing blocks 1I 4to exert a downward pressure thereagainst.

After passing from the pinch rolls 13 and 14, the sheet passes between upper and lower sets of leveling rolls 89 and 90. These rolls are adapted to bend the sheet back and forth during its pas- Ysage therebetween, similar to the action of the usual roller leveler, and the sheet passes from the apparatus substantially flat. The upperrolls 89 are journalled in a bearing block 9i, and the lower rolls in a somewhat similar block 92.

The bearing blocks 9| are stationary and each is provided in its ends with vertically extending shafts 93 connected to worm Wheels 94. These worm wheels mesh with worms 95 carried by shafts 96, and accordingly rotation of the shafts 96 is adapted to rotate the shafts 93. The lower ends of the latter shafts are threaded as at 91 in bosses 98 carried by the lower bearing block 92, and accordingly it will be apparent that rotation of the shafts-93 is adapted to transmit vertical movement to the bearing block 92. Springs 99 have their upper ends seating against the bottom of the block 9| and their lower ends against the bottom of recesses |00 formed in the lower bearing block 92.

In actual practice, the coils of strip metal are piled one upon another while hot, and the result is that many of the coils are distorted from their normal shapes. For example, one end of the c oil may be substantially circular and the other end elliptical, and it is necessary for the apparatus of the present invention to take care of coils of distorted shapes. For this purpose, a pair of guides lill is supported by the side frame members I0 beneath the arbor 34, as shown in Figures-y 1 and 2. The guides |01 fit substantially close to portions of the side frames iii to permit the coil.

to be moved to operative position. The plate 53 is normally arranged in the lower position shown in Figure 1, and accordingly is in a position to receive one of the coils 56. `.ils soon as the coil is arranged in proper position in the depression 55, the control valve 49 is operated to admit fluid pressure into the bottom of the cylinder 2|. The piston 20 accordingly will bemoved upwardly, together withy the piston rod I9, cross-'head i4, lugs 50, roller 25, and the plate 53 through its connections with the lugs 60. Thus the coil 55 will be moved upwardly to the operativeposition illustrated in Figure 1. y

At this point iluid pressure is admitted into the 'piston rod '42. through the pipe 5|, thus build:

ing up a pressure in the outer end of the cylinder 38 whereby it will be apparent thatthis cylinder will be moved outwardly together with the arbor 34. This action is continued until the arbor reaches the operative position shown in Figure 2, at which time it will be rotatably supported by both bearings 35. At this point, fluid pressure is cut oif from the .bottom ofthe cylinder 2i and admitted to the top thereof to move the piston 20 downwardly, together with the elements connect- `ed thereto. Accordingly it will be apparent that the plate 53 will be returned to lower position, while the rollers Il and 25 will be moved downwardly, the latter being brought into engagement with the coil 56.

It will be apparent that the 'reducing valve 41 will supply any desired fluid pressure to the cylinder 2l, and. that the pressure of the roll 25 against the coil will be directly dependent upon the degree of fiuid pressure. In this connection attention is invited to the fact that' the roller 25 is preferably arranged with its axis in the vertical plane of the axis of the arbor 34.

The free end of the sheet from the coil is introduced between the first pair of pinch rolls 13 and 14, and since these rolls are positively driven, the sheet will be withdrawn from the, coil and the coil will be progressively unwound. The unwinding of the coil obviously revolves the arbor 34, the bearings 31 permitting this revolving action to take place. During this action, however, the cylinder 33 will be held against revolving by the arrangement of the nger 39 in the guide slot 40 'I'he sheet also passes between the second pair of rolls 13 and 14 and accordingly these rolls also act as pinchrolls gripping the sheet to unwind, the coil. From the pinch rolls, the sheet passes between the leveling rolls 99 and 90 and is discharged therefrom in substantially fiat form. As previously stated, the present invention does not operate to remove coil breaks from the sheet, but on the,con trary it definitely prevents the formation of coil breaks. If the roll 25 is merely brought into contact with the outer face of the coil and the pinch rolls 13 and 14 operate to unwind the coil, the resistance to the turning movement of the coilA will be substantially negligible and the result will be that ,the

sheet will not be tensioned. as it is unwound and will not closely follow the curvature of the roll 25. Such-operation of the apparatus will not effectually prevent the formationgof coil breaks.

It has been found however that if the turning movement of. the coil is resisted to a sufficient extent, the pinch rolls subject the sheet to a substantial tension outwardly from the point where the sheet leaves the coil, and the sheet, as it is,

progressively unwound, is held under such tension and is forced to hug" the surface of the roll 25 to accurately follow the curvature thereof. In actual practice, this action causes a perfectly uniform cold working of the sheetaround the metal working roll 25, and the formation of the coil breaks is prevented at their usual source.

The resistance to the turning movement of the coil may be accomplished in any desired manner.

For example, the brakes 23 may offer frictional resistance lto the turning movement of the roll of the fluid operatedl piston 25 andassociated parts. In this connection, attention is invited to the fact that the surfaces of the sheet are not perfect as in the case of machined metal surfaces, and the successive convolutions of the coil are subject to compression to some extent. 'Ihe holdingof the roll 25 against the coil under substantial pressure causes the roll to slightlyembed itself into the` coil, and the pulling of the shet is accomplished only against substantial resistance sincethe embedding of the roll 25 must move progressively around the coil.

In other words, it is necessary forthe presfio sure of the roll 25 to compress successive portions of the coil as the strip is progressively unwound, and the resistance to the turning movement of the coil thus generated has heen found particularly effective for forcing the progressively unwoundstrip to snugly follow the curvature of the metal working roll 25, thus eiiecting a perfectly uniform progressive working of the grain structure of the sheet. In setting the pressure at which the roll 25 is maintained in engagement with the coil, it merely is necessary to progressively increase the pressure in the upper end of the cylinder 2i luntil the sheet snugly engages the surface of the roll 25. Slightly less pressure may be employed, if desired, in whichcase added resistance to the turning movement of the coil may be provided through such means as the".

brakes 28. rihe reverse breaking of the .sheet `around the roll 25 obviouslytends to cause the tends to maintain the curvature of the coil for f around the first of the lower pinch rolls lt.. Durpractical difficulties.

the reason that it has become partially annealed and 'set in such'` shape, the cold working of vthe sheet around the roll 25 increases .the plasticity of the sheet, thus permitting it to readilyv flex ing such period however the sheet is maintained under tension and cannot kink or break, although there is substantially negligible tendency for this to occur in view of the cold working of the sheet.

As previously stated, close to the ideal operation of the apparatus for practicing the method would involve the Vcarrying of the sheet 180y around the roll 25, but an apparatus for this purpose has been found to involve substantial Accordingly the present apparatus has been devised and it has been found that highly advantageous results can be obtained by causing the sheet to pass around approxin'iate-I ly 80 of the roll 25. Ordinarily, it is unnecessary to add to the resistance tothe turning movement of the'coil by the use of the brakes 23, but with sheets of certain types this is advisable since relatively high pressures vof the roll 25 against the coil are necessary when the sheet passes substantially 80 around the roll 25. lt is Wholly practicable to reduce the are through which the. sheet contacts with the roll 25but greater addi# tional breaking of the coil is necessary as the degree of curvature of the sheet around the` roll ure `1, but they may b'e raised or lowered slightly by proper operation of the shafts 19 and 84'. The

pinching action between the rolls 'I3A and It is accomplished through the medium of the springs 81, and the tension of these springs readily may bevariedby'operatlon offthe shafts. Thus it willbe apparent that apropergripon the sheet I' ,may be provided to enable the sheet to be un#- ...and smooth.

wound against the resistance offered to the turn- .ing movement of the-coil 56. After leaving the pinch rolls. the strip or sheet travels to the level- 'ing rolls where it is successively and progressively exedv back and forth, and in accordance with the usual' operation` of a roller leveler the sheet is delivered from the apparatus perfectly dat ter the coil hasheen `coxnpletely unwound, air iii-admitted into the cylinder' 38 through pipe l2. and thus the arbor will be retracted to norformation of coil breaks'.

mal position wholly outwardly of the adjacent side frame i0. Another coil is then rolled into position on the plate 63, whereupon the valve 49 is operated to admit air into the lower end of the cylinder 2l and exhausted from the upper end thereof. The coil thus will be elevated to its proper position while the rolls i3 and 25 will be elevated above operative position. The cylinder 3u is then again moved to operative position to support the coil on the arbor, and the apparatus is again in position for operation upon the downward movement of the piston 2o and roll 25.

From the foregoing it will be apparent that theA presentd invention is clearly distinguished from prior attempts to remove coll breaks from metal strip in that it prevents the formation of the coil breaks instead of merely attempting more or less unsuccessfully to remove them. Ac-

cordingly the resultant sheet is adapted for use in high class work, such as the formation of automobile body panels, andthe advantages of winding strip sheet metal in coils accordingly may be extended to sheets of any width. 'I'he invention thus results in great economy in the manufacture of sheet metal for various purposes.

It will he apparent that the present methodv is concerned primarily with the pulling of the strip or sheet from the coil around a metal working member of curved shape, while resisting the turning movement of the coil at least suiiiciently to cause the sheet to snugly follow the curvature of the metal working mernbr as the strip is unwound from. the coil.` The mere. tensioning of the sheet is not suicient to substantially prevent the formation of coil breaks, but the forcing of the sheet'to1 follow the curvature of the metal working member uniformly cold works the sheet, thus increasing its plasticity and preventing the l The method further contemplates the resistance to the turning movement of the coil by the pressure of the metal working member, it having been found that the pressure of theV metal working member against the coil'will offer the desired 'resistance to the turning movement of the coil for the purpose stated. The practice of the method results in the reduction of a finished sheet of surprisingly velopment of strains in the metal, which always results from coil breaks. l

It has been found vthat greatly improved results .are obtained `with strip steel cold rolled` after having been. treated in accordance with the present method..A ,Such improvement is the result'of the complete uniform kneading of the metal to a high degree of cold plasticity, free from intermittent cross breaks that partially rupture the metal at intervals where the strip is permitted to mok inthe regular practice of nnceiling. Where the kinks occur, the metal has been greatly overworked and the further cold yworking ofthe metalzsuch as by lroller leveling, recoiling or any other known process, will not correct the damage 'caused by coil breaks, although some improvement is noted when the metal is treated in accordance with certain prior methods and apparatus. The intervening metal Vbetween the cross-'breaks cannot be worked to an extent that will approximatethe overworking of the metal at the lineof `the cross breaks to provide a uniform surface structure and the results of the rupturlng of the metal at the cross breaks can be only partially overcome. The

effect of the cross breaks thus is apparent on the finished sheet after cold rolling. The present method and apparatus instead of attempting merely to correct the damage after it has.

` than can be obtained with any prior methods f which we are aware.

As previously stated, the resistance to the turning movement ofY the coil is most advantageously provided by clamping the convolutions of the coil between the metal workingvroll 25 and the arbor 34. In the first place, greater uniformity in the resistance to the turning movement can be obtained, and the pressure between the elements tends toA embed the roll 25 in the coil due to the tight compressing of the convolutions of the coil against each other, and a better metal working action is thus provided. Of course, the pressure employed in the upper end of the cylinder 2| will depend upon the gage of the metal being worked and the width of the strip material wound on the coils. The greater the thickness of the metal and/or thegreater the width thereof, the more pressure will be employed to secure the desired results;4

It is to be understood that the form of the invention and the method herein described are to be taken as preferred examples of the same and that various changes in the practice of the method and in the size, shape and arrangement of parts may be made without departing from the spirit of the invention or the scope f the 'subjoined claims.

We claim:

1. The method of uncoiling hot rolled sheet A metal to prevent the formation of coil breaks therein which comprises maintaining a cylindrical metal working member in engagement with the coil in a position parallel to the axis thereof, transmitting a pull to the free end of the sheet to cause it to pass around a substantial arc of the metal working member, and simultaneously resisting the turning movement of the coil at least to a suflcient extent to cause the sheet to snugly follow the curvatureof the metal working Y member, whereby the metal of the sheet is worked to impart thereto a substantial degree of plasticity.

2. The method of uncoillng hot rolled sheet metal to prevent theforrnation 'of' coil breaks therein which comprises arranging a cylindrical,

metal working member in engagement with the coil in a position parallel to the vaxis thereof,v

transmitting a pull to the free end of the sheet to cause it to pass around an arc of at least 80 degrees of the metal working member, and simultaneously -maintainingV the metal working lmember under pressure against thecoil to resist the turning movement thereof to a suicientextent to cause the sheet to snugly follow the curvature of the-metal working member through its arc of contact therewith, whereby-the metal of the sheet is worked to impart thereto a substantial degree of plasticity.

3. The method of uncoiling hotrolled sheet metal to prevent the formation of coil breaks therein which comprises clamping the convolutions of the coil between a mandrel and a transversely curved metal working member, and uncoiling the sheet by exerting a pull on the sheet in a plane at a substantial anglewith respect to a plane tangent to the coil at the'line of Contact 0f the metal working member therewith to cause the sheet as it leaves the coil to pass around a substantial arc of said metal working member in snug contac't therewith, whereby the metal of the sheet is worked to impart thereto asubstantial degree of plasticity.

v 4. The method of uncoiling hot rolled sheet metal to prevent the formation of o coil breaks therein which comprises supporting the coil on a mandrel, maintaining a transversely curved metal working element in engagement with the coil outwardly thereof, uncoiling' the sheet by transmitting a pull to the free end of the sheet in a plane at a'substantial angle to a plane tangent to the coil at the line of contact of the metal working member therewith, and resisting the rotation of the coil at least to a suicient extent to cause the sheet as it is progressively unwound to snugly follow the curvature of the metal working element by exerting a relative clamping pressure of the mondrel and metal working velement against the convolutions of the coil, whereby the metal of the sheet isworked to impart thereto a substantial degree of plasticity.

5. Apparatus of the character described comprising means for rotatably supporting a coil of hot rolled sheet metal, a transversely curved metal working member engageable against the coil along the line at which vthe sheet'leaves the coil, means for transmitting a pull to the-free end of the sheet at such an angle as to cause the latterto pass around a substantial arc of said metal working member, and means for resisting the turning movement of the coil at least to a sufficient extent to cause the sheet to snugly follow the curvature of the metal working member through its arc of contact therewith, whereby the metal of the sheet is worked to impart thereto a substantial degree of plasticity.

6. Apparatus of the character described compris/ing an arbor for rotatably supporting a coil of hot rolled sheet metal, a transversely curved metal working member engageable against the coil along the line at which the sheet leaves the coil, means for transmitting a pull to the free end of the-sheet at such an angle as to cause the sheet to pass around a substantial arcV of said 'metal working member, and means for eiecting a clamping action between said metal workingmember and said arbor to resist the turning movement of the coil to cause the sheet to snugly follow the curvature of said metal working member throughout its arc of contact therewith, whereby the metal of the sheet'is worked to impart thereto a substantial degreeV of plasticity.

7. Apparatus of the character described c'omprising an arbor for supporting a coil of hot rolled sheet metal for rotation, a pair of pinch rolls arranged parallel to the axis of the coil andv adapted to engage the free end of the sheet to metal working member engageable against the coil at the line at which the sheet leaves the coil, and means for resisting the turning movement of the coil to a suicient extent to cause the sheet to snugly follow the curvature Jof said metal working member as the sheet is progressively unwound from the coil, said pressure roll and said pinch rolls being so arranged with respect to each other as to cause the sheet to pass around a substantial arc of the metal working member, whereby the metal of the sheet is worked to impart thereto a substantial degree of plasticity.

r8. Apparatus of the character described comprising anarbor for supporting a coil of hot rolled -sheet metal for rotation, a pair of 'pinch rolls adapted to engage the free end of the sheet to unwind it from the coil, a pressure roll engageable against the coil at the line at which the sheet leaves the coil, said pinch rolls being oiset from the plane of tangency of` the sheet at the line at which it leaves the coil tocause the sheet to lpass around aportion of the surface of said pressure roll, means for clamping the convolutions of the coil between said arbor and said pressure roll at a predetermined pressure, and adjustable brake means for resisting theturning movement of'said pressure roll to cause the sheet to bev 'sub- Jected to a substantial longitudinal tension between said pressure roll and said pinch rolls.

9. Apparatus of the character described com\ adapted to'engage the free end of the sheet to unwind it fromthe coil, and means for resisting the turning movement of the coil to subject the sheet to a substantial longitudinal tension as it is unwound from the coil.

10. vApparatus of the character described comprising an arbor adapted to' assume an operativeposition within a coil of hot rolled sheet metal to support the latter for unwinding, said arbor being axially movable to inoperative position, power means for effecting movement of said arbor between operative and inoperative positions, means for elevating the coil to and supporting it in operative position to be engaged by said arbor when 4the latter is moved to operative position, means for engaging the Ireeend of thesheet to unwind it from the coil, and a pressure hmember engagee able against the coil to resist turningmovement thereof while being unwound.

1l. Apparatus constructed in accordance with claim 10 wherein said pressure member engages against the coil along -the `line at which the sheet leaves the coil, the means for unwinding the sheet 4 being arranged to pull the `free end thereof in a.

plane arrangedat an angle to a tangent to the for axial movement between-operative and inoperative positions, means for elevating a coil of hot rolled sheet metal to and supporting it in op'- erative position to be engaged byvsaid arbor when the latter is moved to operative position, a pair of pinch rolls arranged parallel to said arbor and' engageable with the free end of thelsheet to unwind it from tlie coil, and a pressure roll movable into engagement with the coil to clamp the latter under pressure between said arbor and saidpressure roll, said pressure roll being arranged to con- `tact with the coil along the line at which vthe sheet leaves the coil, said pinch rolls being oiset from a plane tangent to the coil at the point of contact of said pressure roll therewith ,whereby the free end of the sheet is caused to travel partially around said pressure roll in a curve opposite' `to the curvature of the convolutions of `vthe coil, means for sup'porting Vsaidvpressure roll for movement in a plane coincident with the axis of the -pressure roll.

coil, and :duid pressure means for causing said pressure rol1.to remain in contact `with the coil under substantial uniform pressure as the coil unwinds. l

1 3. Apparatus of the character described comprising a support including a pair'of spaced side frames, alined bearings carried by said side frames, an arbor rotatable in said bearings and axially slidable from an operative position within said frames to an inoperative position to one side of 'said support, said arbor when in operative position being adapted to support a coil of hot rolled sheet metal for rotation, a pair of pinch rolls arranged to-one side of said arbor and parallel thereto, said pinch rolls being adapted to engage the free end of the sheet to unwind it from the coil, a pressureroll engageable against the coil along the line at which the sheet leaves the coil, and means for resisting turning movement of said pressure roll.

14. Apparatus of the character described cornprising a. horizontal rotatable arbor adapted to support a coil of hot rolled sheet metal, a pair of'` pinch.r0lls mounted above and to one side of said arbor and parallel thereto, said pinch rolls being adapted to engage the free end of the sheet to unwind it from theu coil, a pressure roll engageable against the top of the coil, said pressure roll having its axis arranged substantially in the vertical plane of the axis of said arbor and contacting with the coil along the line' at which the sheet leaves the coil, the horizontal plane through the line of contact of the pinch rolls with the sheet lying above the horizontal plane of the line of contact of said pressure roll and the coil, and a 'second pairof pinch rolls lying adjacent and parallel to said iirst pair of pinch rolls and positioned with respect thereto to cause the portion of the sheet passing between the two pairs of pinch rolls to travel in a plane at an angle to the plane of the portion of the sheet traveling between the coil and -the first 'named pair of pinch rolls whereby the sheet is caused to travel partially around the lower pinch roll of the first named pair. f

15. Apparatus of the character described comprising an arbor for supporting a coil of hot rolled sheet metal for rotation, a pair of pinch rolls adapted to engage the free end of the sheet to unwind it from the coil, a pressure roll engageable against the coil at the line at which the sheet leaves the coil, and means for maintaining said pressure' roll against the coil and the coil against said arbor at a predetermined pressure to resist the turning movement of said coil as the sheet is uncoiled, said pressure roll and said pinch gageable against the coil at the line at which the,

sheet leaves the coil, said pinch rolls being offset from the plane of tangency of the sheet at the line at which it leaves the coil to cause the sheet to `pass around a portion of the surface ofl said pressure roll, and means for clamping the convolutions of thel coil between said arbor and said AMBROSE J. WARDLE. HARVEY D. NIILLER.