CA1089758A - Sheet metal web handling method, apparatus and coil construct - Google Patents

Abstract

STEEL METAL WEB HANDLING METHOD, APPARATUS, AND COIL CONSTRUCT

ABSTRACT OF THE DISCLOSURE

The disclosure includes method and apparatus for handling elongated webs of sheet metal, and a sheet metal construct formed as an intermediate product and comprising a parent coil pre-divided into a plurality of daughter coils. In one method sequence, separation can be completed by the end user of the coil just before it is fed into a press or the like. In another method sequence, separation is completed during wrapping of the parent coil. In still other sequences, completion of separation can be accomplished at stages intermediate these two.
Slitting may be done directly off a mill. Edge trim strip may be wound as part of the parent coil to simplify scrap handling, and may be used to protect the coil in transit.

Description

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' 1089758 ~ACKGROUND 0~ THE INVENTION
In the manufacture of flat rolled metal it is most convenient and economical to form the web of a much greater width than is normally required by the end user and then slit the web into narrower strips of a suitable width. The metal web is coiled as it is processed, then, in a separate operation, placed on an uncoiler, unwound, trained through a slitter and then rewound as a number of separate narrower strips on the coiler. The slitting operation may be accomplished at the point of manufacture, by middlemen, such as warehousemen, or by the end user of the sheet metal.
Regardless of at what point the coil slitting takes place, inherent characteristics of the sheet metal and conventional coil slitting processes result in a number of difficulties to which the industry has responded in a manner which, in many cases, only solves the problems en-countered by producing other, dlfferent problems.
For example, although the sheet of metal being slit is generally thought of as having a rectangular cross-sectional configuration, in fact, conventional sheet metal manufacturing processes produce a sheet which is crowned, i.e. is thicker, at its center than at its edges. Obviously, as such a sheet is rewound on a coiler as a series of separate strips following slitting, those strips slit from the center of the sheet are thicker and as a - result aré rewound more tightly than those strips slit from adjacent the edges of the sheet. This in turn results in so called "slack strands" being formed by the thinner strips between the slitter and coiler. To overcome the problem of slack strands a number of solutions have been advanced, and in fact are found in use today throughout most coil slitting operations.

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' 108g758 One approach has been to insert pieces of cardboard or paper between the wraps of those coils positioned outwardly of the center coil to compensate for the differences in thickness of the strips being rewound.
This is often performed manually, which is both cumbersome and dangerous, and even where performed mechanically is still cumbersome and requires a specially designed machine. In both cases, the cardboard or paper pieces must be removed later as the strip is decoiled for punching, pressing or other operations.
Two other, related approaches to the problem of slack strands are the looping and festooning of the strands intermediate the slitter and the coiler. Looping requires the provision of a deep pit, which is both inconvenient and expensive, while festooning requires the in$tallation of a series of rolls mounted in towers above the process line, an obviously costly expedient, and in both looping and festooning control of the slack stands is always a problem.
~ hile individual coilers could be provided for each of the strips resulting from the coil slitting operation, as a practical matter the expense of such provision will usually be prohibitive. Another approach which is based upon individual treatment of the slit strips but which does not require separate coilers is slip core winding. In this process, the strips are wound on nonmetalllc cores that are allowed through friction to wind at a speed commensurate with the thickness of the strips. However, the cores used in this operation are in themselves expensive and must be retained within and shipped with the coils, and in addition they may distort under load and cause irregular winding.

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Another problem characteristic of conventional coil slitting operations which is independent of the crowned configuratlon of the metal sheet and would, therefore, exlst even lf the sheet were perfectly rectangular in cross section,-is interleaving of the strip edges as they are rewound on the coiler. Interleaving in turn results in damage to the edges of coil, loss of production time resulting from the necessity of manually separating interleaved coils and difficulties in feeding such coils, because of their damaged edges, through machinery such as punching presses and the like.
To prevent interleaving during rewinding, an attempt is generally made to keep the individual strips separate from each other. This may be accomplished by posltioning spacer plates between coils or through the use of a series of discs which are mounted on a shaft separate from the coiler and allowed to penetrate between the coil edges as they are rewound.
Regardless of the particular manner in which separation is attained, it will be seen that separation requlres lateral displacement of the individual strips from each other. This in turn requires that the coiler be spaced a considerable distance from the separator to allow the strips to fan out gradually from the slitter to the required spacing at the coiler.
Ordinarily, to obtain a total lateral displacement of approximately two to three inches it is necessary to provide from fifteen to twenty feet of spacing between the slitter and the coiler.
From the above it will be apparent that conventional coil slitting operations possess many lnherent disadvantages and present many problems which have traditionally either been accepted or only partially solved, often at the expense of introducing other difficulties and new problems into the process. A need therefore, has long exlsted for a n _ .. ~. : . , : . , :
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` 10897S8 approach to coil slitting which obviates the prob]ems of slack strands and coil interleavill~ and all of their attendant disadvanta~es.

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- In accordance with tho prcsent inventioll coil ~ittin~ is accômplished in a two step operation ~liCtl permi~s all of ~he sLrips slit from a sin~le sheet to be rewound as a unit and thereb~ obviatcs ' . the tradltional coil s'litting problems of slack stran~s and coi].
interleavin~. ' ~; . This application, being a division of Canadin~ Application i 10 Serial No. 260,888, filed September 10, 1976, claims only certain aspects of the invention fully disclosed below.
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-' Althougll cutting web material in more thall oue cutting step '. ; is not unknown (see for example, U.S. Patent No. 876,008), includlng cutting of metal strips in more than one step (U:S. Patent ~os. 3,628,710 ant 3,641,85~), in such prior art cutting processes completion of cutting i8 accomplishet'before.rewinding of the sheet being cut has com~enced.
: As a result, the same-problers of slack strands and interleaving that occur in conventional, one step cutting processes wou].d occur in a two : step process.where the final cutting step is'accomplislled ~efore rewinding ~ 20~ has commenced, to the same extent that they would have occurred had the ''~: :: . - ' ~ : cuttlng been accomplished in only one step.
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, In contrast, in accordance with the present invention, as the unslit sheet is unwound from the uncoiler and trained through the slitter, the sheet ls only partially slit or cut, or is fully slit and i~ediately '~ ' ~ -5-.

lightly reconnected to provide the equivalent of partial slits or cuts, resulting in a set of interconnected strips which are delivered to the coiler as a single sheet. Thereafter, after.rewinding has commenced, that is, at any time between the time when the interconnected strips have begun to wrap the coiler reel and such time as the coils are unwound for use, the partial cuts or equivalents made at the slitter may be completed to provide the separate, narrower coils desired.

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Since, until the partial cuts or equivalents made at the slit~er are completed, the intercollnected strips behave as a single she~t, thcy can be treatcd as such during coiling without fear of slack strands, strip interlcaving and all of their attendant problems and difficulties.

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In accordance with one embodiment of Lhe invcntioll, coml-lete separation of the coils is not made until the coils arC u]~ima~ely unwoulld by the ead user as, for example, they are fed into a press. In accordallcc with this embodimellt, an additional advantage is gained over and above thosc ~discussed above in that individual banding and handling of se~aratc coils ~O following the slitting oper~tion are eliminated. Or tlle coils may be individually bro~en off as units,~preferably by the end user, rather than being individually unwound in which case individual handling may both (1) be more eEficient than in conventional practice and (2) require little challgc from conventional practice in utilizing ordinary handling equipmellt such as cranes or lift trucks to transport and position indivldual sllt coils.

In accordance with another embodiment of the invention, completion of the partial cut is made during the first wrap of the coils on the coiler mandrel. In accordance with this embodiment of the invention, final separation - i8 made preferably as close as possible to the beginning of the second wrap, allowing the first wrap of interconnected sheets to theeeby act as a wrapper for the separated coils.

, Regardless of whether final separation is accomplished on the coiler or at some later stage, the final parting arrangement can be relatively simple.

In a conventional slitter opposed pairs of rotary cutters are uset at each cut, which results in adjacent edges of the sllt coils being momentarily dispiaced from each other in a dir~cti~n perpen-ticular to the plane of ~he slleet. In the practice of the present invention, the same '' - ' . .' . ~ .,' .'. ' ', ' momcntary displacement may occur at longitudinal locations whcrc slitting is complete, but the resulting series of interconnccted strips may also'cxpcricnc~
a degree of relative displacement of adjacent cd~es at longitudinal locations where slitting is not complcte, which displacement may be m~intain~d until the adjaccnt strips are scparated, unless the s~rips arc ~noc~ed back dow into a common plane while maintaining the conncction bctwerll sllts, as ls presently preeered. Sciving tools can then be used to separate the strips.
Or, the adjacent edges of the strips may recovcr from their mom~ntary displacen~ent at all loca~ions in the practice of certain forms of the inven~ioll, particu~arly ~ where the sheet is fully slit and thcn i~uediately lightly recollnected.
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If thé connection after par~ial cutting or equivalent is sufficiclltly delicate, a contoured bending bar or knockdown bar'can be utilized bearing on the faces of the interconnected strips, lf dcsired with an endless belt or belts interposed between the bar and the faces of the strips to ellmlnate sceatching and other damage to the strips, to break the remaining bonds bctwcen 'ad~acent strips by pressing their edges back towards a common plane or by pressing them momentarily out of a common plane. Or sciving tools can be used ~20 to separate the strips~either upon coiling after slitting or upon final un-coiling. Or, the daughter coils formed by the partial'slitting or equivalent ~- can be broken away from the parent coil, either slmultaneously or one at a time, , ~ , ' .
Of cour e, other separatlng tools can also be utilized, including, but not llmited to, sharpened rotary cutters slitting the connections betwecn ad~acent strips as thri strips are coiled following partial slitting or at any ~ 't'ime ollowing commencement of coillng but before end use.

;~ It will also be seen that under certain circumstances an additional piece of equipment for completlng the cut may be unnecessary. Thus, where tl-e ~o partial cutting operation results in a series of interconnected strips having thè still-connected portlor,s of their edges displaced from each other in a .,'-' .
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~--`` lQB97~i8 direction approximately perpendicular the plane of the strips, by controlling rewind tension the remaining bonds between the sheets may be fractured as they are wrapped tightly on the coiler reel. Or, the partial cutting or equivalent may result in a connection which will maintain itself until the connected strips are bent around the winding axis, as upon winding of the connected strips, at which point fracture may occur due to the bending incident to winding. Or, the connection may satisfactorily yield only to differential unbending around the winding axis, as upon unwinding of one of the connected strips while the other remains wound. Or, the connection may or may not resist such differential un-bending to an objectionable degree, but may nevertheless satisfactorily yieldto imposition of spreading forces between the strips because of the "stiff plane"
efect of the connected strips ln resisting such spreading forces. Or, combina-tion of such bending or unbending together with such spreading may be employed, as upon unwinding by pulling the unwinding reach in an unwlnd path that has a vector component that is parallel to the axis of the coil, or by simply tilting the roll axis away from the horiæontal and toward or to a vertical position to thereby allow gravity to assert such a pull. Or, the daughter coils may be broken away from the parent coil, either simultaneously or one at a time, with-out the use of special tools but simply by impact or pressure, as upon being dropped on or forced against a flat or stepped surface, or upon being struck head-on or glancingly by an industrial truck fork or by a crane hook or the like, or simply by sheer weight when support by a mandrel or the like is removed from a daùghter coil in some cases where heavy coils have relatively infrequent and/or highly weakened tacking.
The configurations of the cuts made during the partial slitting operation or equivalent are susceptible to variations within the scope of the present invention. For example, the cutters can be provided with small, profiled flats ground into a face of the cutter adjacent its edge, thereby providing tacks or connections across the slits made by the cutter. Special shapes other than flats ; can be used to accomplish the tacking, as described below.

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~ 1~89758 In a variation, the cutters may be arranged to run cccentrically very slightly ancl adjuste-l vertically so that alternatc complete slitting and incomplete sliLting is accomplished. rhe incomplc~:c sliLs bctween - completely slit sections would then be separat:ed in any of ~hc dif ~ercnt separating processes descril~e(l above.

In another variation, the arbor of the upper cutter could bc mounted for a sllght amount of vertical movernent, ordillarily on the ordcr of a few thousandths of an inch, and cam or othenl~ise controlled to provide a periodic lif ting of the arbor and cutters mounted thercon to 10 tack across the slitting each time the arbor is lifted.

In another varlation, flats on the upper'and lower cutters can be brought ~nto an-l out of rotative register with each other to alternatcly accompllsh full slitting or tacking.

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1()89758 In still another variation, the cutters can be adjusted vertically so that the sheet is sheared just short of the point of fracture in a continuous, uninterrupted fashion, or as called for when sensors indicate incipient or actual nonuniformity of wrap during full slitting. This alternative is appli-cable, for instance, when completion of separation is made during the first wrap of the coils on the coiler mandrel. Separation of the strips at the coiler can take place in any of the methods described above.
As indicated above, instead of partially slitting, the cutters may be arranged to continuously completely slit followed however by i~mediate partial reconnection at a rolling station ~ust beyond the slitting cutters so as to thus, equivalently to partial slitting, maintain the edges of adjacent pre-slit strips connected together during winding.
In the present invention, the slitter and coiler of the slitting line can be related in a new way in which relatively close coupling between slitter and coiler exploits and, so to speak, "captures" the mo~entary condition of tracking in parallel which is imposed on the edges of the daughter-coils-to-be by the action of the slitting rolls. Close coupling is therefore a positive characteristic of the preferred operation of the invention.
As noted above, one major advantage of the partial slitting, or equivalent, of the present invention is the elimination of the problem of inter-leaving. As also noted above, the conventional approach to this problem is the use of separators between the slit strips, which in turn necessitates the positioning of the slitter from the coiler at a considerable distance to allow the slit strips to fan out to the lateral displacement necessary to attain separation. Since lateral displacement is no longer necessary when slitting in accordance with the present invention, the requirement that the slitter be spaced a considerable distance from the coiler is eliminated with a consequently much ore compact process line and a resultant substantial saving in floor space.

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,. , 1~1897S8 The requirement of considerable spacing is not only eli~inated but significant operating improvements are achieved by the converse of considerable spacing -a close-coupled relationship between slitter and coiler. Slitting directly from a rolling mill becomes feasible, such as at the last stand of a five-stand tandem cold mill or at a temper mill.
Where final separation is performed by the end user, the elimina-tion of individual banding and handling of separate coils is a major advantage of the invention. Instead, the original parent coil may be formed into a coil construct comprising an array of daughter coils which can be handled together until readily separated by the end use~ or the warehouser or other middleman.
- A particular advantage is the improved handling of scrap, and improved protection of coils in trans-shipment. Edge trim can be wound as disc-like coils at each end of the array of regular daughter coils, rather than having to be balled, chopped or wound in the conventional manner. These disc-like coils then serve to protect the edges of the endmost regular daughter coils during shipment, and can be readily~broken away at the site of coil use and, in some applications, even handled as a unit until remelted or reclaimed.
Pinal separation of this construct can be accomplished by individually unwinding one after another of the daughter coils which can be supported together on a single mandrel or unwinding stand to be successively (or even simultaneously) presented and fed to a working line or lines. Or, the - daughter coils may be broken off as units prior to unwinding. This can optionally .
be done with breakaway grabs carried by cranes or lift trucks or by their own carriages or the like, so that the daughter coils can be handled by the end user in an efficient manner but in such a way as to be compatible with past procedure in handling individùal coils.
Even with the complete elimination of edge interleaving, edge ~verhand can occur -- a condition where a turn of a daughter coil being uncoiled :: .

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is overhung b~ a radially outward tu~n of an adjacent daughter coil so that interference between the edges results. ~ feature of the present invention eliminates this condition by "step-tracking" the daughter coils on themselves, as more fully explained below. According to another feature, edge overhang is eliminated by dishing the daughter coils. However, in the presently preferred approach in experimental trials, neither "step-tracking" as such, nor dishing is utilized, but natural tracking upon winding is nevertheless sufficient to entirely avoid edge overhang and provide good coil alignment with breakable interconnections between daughter coils disposed for clean shearing action as upon lateral loading of adJacent daughter coils in opposed directions.
From the above and from the following detailed description, it will be seen that the present invention provides an entirely new approach to coil slitting operations and eliminates many difficulties, disadvantages and problems associated with conventional processes by not attempting to combat ; these problems, but by simply obviating their source. Further advantages of the invention will appear from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure I is a perspective view of a prior art slitting line;
Figure 2 is a cross-sectional view on line 2-2 of Figure l;
Figure 3 is a perspective view showing a slitting line in accor-dance wlth the present invention; -Figure 4 is an enlarged cross-sectional view taken on the plane of line 4-4 of Figures 3 and 5; -Figure 5 is a cross-sectional view taken on the plane of line 5-5 of Figure 4;

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Figure 6 is a diagram of the momcntary posiLions at the slitting nip of the edges seen in Figurcs 4 and 5 a~ different ro~aLiVe ~ositions of the slitting rolls;

Flgure 7 ls a fragmentary view of the edge of a relievcd cut~er which thc invention may employ;

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Figure 7a sl~ows the edge of anotller relieved c~tter whicll Lhe invention may cmploy;

: Figure 8 is a side elevation of an array of da-l~hter coils; ~ -Figure 9 ls a schematic fragmentary cross-sectional view, iEnoring ~lO sheet crowning, of the upper left edge of the coil array seen in Fi~uro 8, ,.~! ; .
taken on the plane of the~paper;

Figure 10 is a view similar to Figure 8 witll one of the ~aughter ( ~ colls psrtially removet;

- ~ , Figure 11 ls a side elevation of another array of daughter coils;

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lgure 12 is a schematic fragmentary cross-sectional view, iEnoring : sheet crownlng, of the upper left edge of the coil array seen in Figure 10, . taken on the plane of the paper;-~ , j, Flgure 13 is a schematic side elevation, partly in section, `:~: illustrating a means for separation of taughter coils at the point of use;

~Z Figure 13a and 13b are respectlvely fragmentary plan and elevatlonal vlews of a p~rt of the apparatus seen in Figure.13;

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: `. ` 1(?89758 Figure 14 is a scllematic sidc elcvation, part]y in cross-section, showing an opera~ion in accordance wlth tl~c present lnvontlon where separatlon is completed at the coiler; ~ ~.

Flgure 15 is a view similar to Figure 14 but sl-owing a modified operation for complcting separation;

Figure 16 is an end elevational vi~w of a sliLLi.l~g opera~iol~ sllowing another opcration for completing scparation;

Figure 17 is a side elevational view illustratinE the usc oi thc invention at the outfeed end of a tandem mill;

\ Figure 18 is a perspective view of a working model of the invcntion;

Figure 19 is a perspective view of a coll construc~ contelrpl;lted by the invention, Figure 20 is a fragmentary detail of Figure 19;

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Figures 21 and 22 are schematic cross-sectional view~ taken across :.
the straight reach of slit strip seen in Figures 18 and 23 at different points pr$or to the wrapping thereof to form the coil construct;

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Figure 22a is a schematic cross-sectional view taken across the stralght : reach of slit strip seen in Figure 23 prior to the wrapping thereof, but whe the machine is set up somewhat differently than when it produces strlp having Z0 the cross-.sections schematically illustrated in Figures 21 and 22;
.~ i Figure 23 ls a side elevatlon, partly broken away, of the working model of the invention;
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Flgure 24 ls an end elevation thereof, partly broken away;

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Figure 25 is a View of a sciving tool used in the model;
Figure 26 is a side elevation, partly broken away, of a modifi-cation of the worklng model seen in Figures 18, 23 and 24;
Figure 27 is a schematic fragmentary foreshortened view of a slit strip or unwound daughter coil containing camber;
Figure 27a is a foreshortened view on a smaller scale showing an ; elongated web of sheet material with serpentine or reversing camber;
Figure 28 is a schematic fragmentary cross-sectional view, ignoring sheet crowning, of part of a coil array containing the strip of Figure 27;
Figure 28a is a very schematic cross-sectional view, ignoring sheet crowning, of part of a coil array containing the web of Figure 27a.
Figure 29 is a plan view, partly broken away, of a slitting line with automated threading contemplated by the invention;
Figure 30 is a side elevation, partly in section, taken on the plane of line 30-30 in Figure 29;
~ Figure 31 is a schematic cross-sectional view of one form of coil breakaway device contemplated by the invention;
Figure 32 is a side elevation, partly in cross-section, of another breakaway device in the form of a coil breakaway grab;
Figure 33 is an end elevation of the device seen in Figure 32; and Figures 34 and 35 are side and end elevations of another break-away grab.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
For purposes of background, Figure 1 of the drawings discloses, somewhat schematically, a more or less conventional slitting line including an uncoiling station 10, a slitting station 12, and a coiling station 14. In accordance with accepted practice, a coil of sheet metal or the like 16 is placed upon an unwind mandrel 18 and trained through the slitting station 12.

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-At the slitting station upper rotary cutters, as at 20, cooperate with like cutters, not shown, disposed beneath the strip and offset with respect to the cutters 20 to slit the incoming strip into a series of narrower strips 22.
The strips 22 are then rewound on a rewind mandrel 24 and a separating device 26 including separating discs 28 serves to prevent interleaving or overhang of the edges of the rewound strips 22.
It will be noted from Figure 1, that in order to provide the necessary separation at the coiling station 14, the slitting and coiling stations must be positioned a substantial distance from each other.

Additionally and with reference to Figure 2 of the drawings, it will be noted that the cross-sectional configuration of the sheet 16 varies considerably from an ideal rectangular configuration, shown in dashed lines in Figure 2, with the center of the sheet actually much thicker than the edges thereof. As a result, strips cut from the center of the sheet are thicker than those cut from areas displaced outwardly from the center and the center strips are, therefore wrapped more tightly than the outside strips.
This results, as seen in Figure 1 of the drawings, in the outer strips sagging between the slitter and the coiler. Although only a relatively small amount of sag is shown in the drawings, it will be apparent that as the slitting and coiling process proceeds, the resulting sag will be substantial, requiring pits formed between the slitter and coiler or a system of rollers for festooning the outer strips above the slitting line.

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~ 1089758 All of the above problems are obviated with the present invention by maintaining limited connectlon between the slit strips at the slitting station and completing their separation after the sheet has commented coiling on the rewind mandrel. Thus, as seen in Figure 3 of the drawings, as sheet 16 is un-wound from the mandrel 18 and trained through a slitting station 30, the sheet is predivided into strips 32 while maintaining limited connection, as indicated by the dash-dot lines 34. Therefore, as the interconnected strips 32 are re-wound upon the mandrel 36 they, in effect, behave as a single sheet.
As a result, there is no necessity of maintaining separation between the edges of adjacent strips, nor do the thinner strips sag between the slitter and the coiler. As will be particularly apparent from Figure 3 of the drawings, because the necessity for lateral displacement of the strips at the coiler is eliminated the coiler may be positioned ad~acent the slitter, providing a much more compact slitting line and, as will be discussed in detail below, rendering possible the use of a single piece of equipment for both partial ~- slitting and flnal separation.
~ ompactness of the slitting line is however only one benefit of the relative adjacency between slitter and coiler. More significant is the achievement of constraints on the strips during coiling to cause them to wind with almost perfect tracking into daughter coils separated by flat side faces.
It has been discovered that momentary constraints imposed by the slitting cutters on the side edges of the slit strips can be "extended," so to speak, by causing the slit strips to behave as a single sheet (by tying the edges of ad~acent strips together, during or immediately following slitting, as herein .
described), and that such constraints can be "captured," so to speak, to be made part of the coiling operation by taking up the slit strips on a coiler before such constraints have dissipated with continuing travel of the strips away from the slitting cutters. The result is daughter coils separated by flat - interfaces through which extend the breakable ties disposed for clean breakaway .
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shearing action. The constraints can acco~plish such flat interfaces despite the almost inevitable occurrence o camber in the sheet material being slit and despite the resultant camber in the slit strips, and even despite a slight degree of yaw in the feed roll supplying the sheet material to the slitter.
The close coupling between the slitter and coiler contemplated by important aspects of the invention can be eliminated, but only at a cost in reduction of tracking accuracy that will often be unacceptable or at least pointless.
Partial pre-slitting, or the equivalent, can be accomplished periodically or n-periodically, and intermittently or non-intermittently. An example of periodic non-intermittent pre-slitting is the use of flats on slitting cutters to periodically produce tacks (upon every revolution of the cutters) without skipping tacks during some revolutions. An example of periodic inter-mittent pre-slitting is a similar arrangement in which the slitting cutters are positioned so that tacking does not occur, but in which such slitting cutters are intermittently shifted to cause periodic tacking to occur~ An example of non-periodic non~-intermittent pre-slitting is the provision of slitting cutters which continually completely slit followed by immediate partial reconnection by the continuous or non-periodic action of rollers positioned just beyond the slitting cutters, without any interruption of such action of the rollers that accomplish reconnecting. An example of non-periodic intermittent pre-slitting is a similar arrangement in which the rollers that accomplish reconnecting are positioned so that such reconnecting does not occur, but in which such rollers - are intermittently shifted to cause such reconnection to occur.
As noted above, pre-division can be accomplished in accordance ~ith the present invention in a number of different ways. For example, the strip can be provided with alternating fully separated and less than fully separated sections. Separated sections of say, a few feet in length, or a few inches in length in the case of thinner material, are joined by less than fully separated .
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'` 1089758 sections of relatively short length. ~lternatively, the strip can be continuously separated and then re~oined, as mentloned above. In some appllcations it may be possible that the opposed cutters 31 (~igure 3) can be provided without flats or reliefs and adjusted to provide a continuous shear line between adjacent strips - 32 with the strip sheared to a point ~ust short of complete fracturing and the fracture completed after rewinding has commenced.
The alternative separated and unseparated areas may be produced in a number of ways, including mounting one or both of the cutters somewhat eccentrically, providing one or both of the cutters with flats or other relief shapes on their peripheries or on the faces near their cutting edges, providing a cam action or the like for ad~ustment of one or both of the cutters relative to each other in directions perpendicular to the face of the sheet 16. The reliefs on each cutter may be each insufficient to prevent full separation alone, but capable of doing so if in registration with the relief on the associated cutter, and the reliefs may be brought into and out of register by advancing or retarding the angular position of one cutter relative to the other, by means of a differential drive or the like, as they both continue to rotate through the cutter nip. Combinations of these arrangements may be provided.
All of the above arrangements for providing partial pre-slitting, or the equivalent thereof, can be referred to as "tacking" arrangements. The slit strips are caused to continue to move together by being tacked together, periodically or non-periodically, and intermittently or non-intermittently.
Both periodic and non-periodic or continuous tacking involve maintaining connection between the slit strip edges sufficient to cause the slit strips to wind together. Such maintaining of connection may itself be non-intermittent or it may be made intermittent by interruptions either on a pre-programmed or on a demand basis.

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As an example of a demand control, as seen in Figure 3, sensor means 33 may be provided between the slitting station 30 and winding mandrel 36 for sensing sagging or tension differences or other differences or incipient differences in winding of the slit strips. The sensor may be any appropriate device such as a tension sensor or, as shown, a photoelectric sensor.
Cutter 31 and its companion are positioned close enough for continuous slitting until such time as the sensor 33 detects differences or incipient differences in the winding of the strips 32 whereupon the cutters are moved apart or otherwise ad~usted by automatic means (not shown) sufficiently to commence maintaining periodic tacking between the edges of the strips 32 sufficient to cause them to wind together. This condition may be terminated after a given time, in terms of distance or time units, or may be terminated after winding differencesor incipient differences are no longer detected.
Figures 4 and 5 illustrate the configuration that may result in the region of a "tack" or periodic partially separated area. The adjacent strips 32 are d~isplaced vertically with respect to each other when they engage the cutte~s, and spring back together when they are fully separated. However in an area of partial separation, the ad~acent strips continue to be joined by a bridge 48 o the parent metal connecting the metal of the adjacent coils ~ .
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; .. . ; . . . . :

. . .
.. : . : . - . . :.

.. .. . . .
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and maintaining the vertical dis~lacement o~ the adjacent strips 32 with respect to each other, as seen in Figure 5, thereby ~aintaining an increased overall thickness of the adjacent strips (consldered together as a unit) and thereby an increased overall thickness at the locations of the bridges in the turns of the array of daughter coils ~ormed upon coiling.
Figure 6 diagrams the momentary positions at the cutter nip of the edges a, b, c, d seen in ~igure 4 plotted against different rotative positions of the cutters. The rotative positions of the cutters corresponding to passage through the nip of the flats on the cutters are between positions e and f. The vertical locations g and h on the diagram represent the height of the top and bottom surfaces of the metal sheet prior to close approach to the cutter, and of the fully slit portions following passage through the cutter.
Even if only one cutter is relieved, the cutting action will be similar to that illustrated in Figure 6. Although the corresponding curves would not be exactly symmetrical about a horizontal axis, they would be roughly similar to the illustrated curves because the adjacent not-yet-parted strips 32 tend to center themselves vertically between cutters even if only one cutter is relieved.
Figure 7 illustrates the relief of a single cutter 61 designed to operate with a corresponding unrelieved cutter (not shown). The circular periphery at 62 is relieved by a flat 63 which is faired into the periphery of the cutter at ends 64 and 65.

, ,~
_ 21 -. . , ,.. , : :. , .

.,, ~ ~ : . - . : . . . ., . : . . .

lQ89758 ~ hen the metal ls coiled after passing through the cutters, a pIurality of daughter coils 71 are formed, as seen in Figure 8. The transverse profiles of the turns of the array comprise raised portions 72 and notched portions 73, as seen in Figure 9, The notched portions such as 73 may be slightly downwardly penetrated by a succeeding wrap of the corresponding daughter coil. Thus in Figure 9 each notch 73 is slightly penetrated by the first succeeding wrap 74 of its corresponding daughter coil 75. (Similarly the second succeeding wrap may penetrate the slight gap 76 left by wrap 74, and so forth in respect of still later wraps, but the occurence of such penetration beyond the first succeeding wrap is not illustrated.) Corresponding upward penetration may also occur with respect to the reliefs under the raised portions 72, as shown, although any such upward penetration will tend to be minimized by the effect of winding tension.
The edges of the daughter coils are thereby kept in alignment to prevent edge ov~erhang in circumstances where edge overhang might otherwise occur due to the particular circumstances of coiling. Thus as a daughter coil 71a is uncoiled as in Figure 10, there is no interference with the face 77 comprising the edges of the turns of the adjacent daughter coil 71b.
The array of daughter coils may be formed in a dished configura-tion as seen in Figure 11. This may be done by shifting the coiler axially in one direction throughout the coiling operation. Each of the daughter coils 81 ~ . .
and each of the interfaces 86 between daughter coils is dished. The edges of ad~acent daughter coils are thereby stepped in a uniform direction, as seen in Figure 12, whereby edge overhang is avo1ded and no edge interference occurs when the daughter coils are individually uncoiled.

` - 22 ~
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'.' '.... ' ' ' . ' ~ '....... . ' ~'' ' ', ' ,' .,'~ ' ' -The arrays of daughter coils are removed from the rewind mandrel and shipped to the end user or the warehouseman or other middleman still inter-connected. Final separation takes place aS tbe strips are needed, using any of the final separating processes mentioned herein.
One particular arrangement for final cutting is shown in Figure 13. Here a daughter coil 88 is being unwound from its parent coil 89, the un-wrap reach being indicated by reference number 90. In this case, to aid separa-tion of the daughter coil,-a prizing blade 91 is provided as most clearly illu-strated in Figures 13a and 13b. This blade is bolted to and held by a wedge finger 92 over which the unwrap reach 90 slides and under which the wound turns of the daughter coil 88 pass. The unwrap reach 90 slides on top face 93 of finger 92. Finger 92 is supported on a flange 97 by a pivot bolt 94 provided with a spring 95 adapted to yieldingly center finger 92 in the illustrated horizontal position. Flange 97 pro~ects from crosshead 98 which slides verti-cally on four columns (two of which are shown) protruding from a pair of spaced pedestal supports (one of which is shown). Raising and lowering is done by actuating cylinder 96. The underside of finger 92 can ride directly on the still wrapped portion of daughter coil 88.
The leading edge of prizing blade 91 may, as illustrated, depend slightly below top face 93 of ~inger 92, so that the blade projects partly into the shear line associated\with the next succeeding wrap of the daughter coil to pre-initiate separation at the turn that precedes actual unwrapping or at least to aid in maintalning the positioning of the prizing blade 91 i~mediately next to the edge of the ad]acent layer of still wrapped coil that corresponds to the then-unwrapping layer of the daughter coil. In some cases such pre-initiation or position-maintaining aid is unnecessary and the depending portion of blade 91 can be omitted.

.. , .. . : . . , , . .: ...... : . .: ~ ,: .
. : : : . . . , . :. . :

: : -:, - : . :: ,:: ., . . , : ~ .: . : . . . , :

The prizing blade 91 acts to laterally wedge or prize the top turn oP the daughter coil that is being unwrapped away from the corresponding layer of the ad~acent still-wrapped coil to a sufficient extent to break the remaining connection between the two. As intimated in the foregoing description, the action may be one more of wedging or prlzing than of cutting.
It will be appreciated that various combinations of partial slitting techniques and separating techniques may be utili~ed in accordance with the present invention. For example, after partial slitting is accomplished by any of the various methods discussed above, the cut may be completed at any time after rewinding has commenced by any of the methods described herein.
In another aspect of the invention, final separation may be accomplished upon rewind. As shown in Figure 14, one possible method of completing the cut formed at the slitter 30 is through the use of a contoured bending bar 38 bearing against the interconnected strips 32 ~ust as they approach the second wrap in the coil being built on the rewind mandrel 36.
Because of the increased thickness at the connecting bridges, the pressure of the bar 38 bearing against the strips fractures the remaining bond between ad~acent strips and completes the cut ~ust before the strips enter the second wrap of the coil. Preferably endléss belts 39 are interposed between the bar 38 and the coil being built to prevent scratching or other damage to the faces of the strips being rewound, and the belts can idle or be driven from pulleys 40 which aré ln turn driven by gears 41 in mesh with like gears 42 fixed to the arbor of the lower cutters.

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~:
- ~ 24 _ Alternatively, as shown in ~i~ure 15, a rolle~ 43 can be used in place of the cont~ured bar 38 to complete cutting of the strips as they enter the second coil. In this regard, a segmented roller 43 can be provided having relatively larger diameter areas 44 in contact with the strips adjacent t~eir longitudinal edges and with the larger diameters 44 interconnected by smaller diameter portions 45.
In another alternative, sharpened rotary cutters (not shown) driven by motors may simply be positioned at the rewind mandrel to complete the cuts between ad~acent strips 32 after they have begun to rewind on the mandrel.
Of course, the unfractured areas between adjacent strips can, particularly where the material being slit is somewhat br~ttle, be fractured by simply controlling the rewind tension.
The compactness of the slitting line that results from the partial slitting techniques of the present invention permits the incorporation into the partial slitting system of special slitting and separating mechanisms.
Thus, as seen in Figure 16 of the drawings, sheet 16 is uncoiled from the mandrel 18 and passed through a cutting station 50 before being rewound on the mandrel 49. ~t the cutting station 50 pairs of opposed cutters 52 and 54 are positioned above and below the sheet similarly to the opposed cutters 31.
However, cutter 54 includes a satellite cutter 56 at its periphery, spring loaded radially outwardly of the cutter 54. Mandrel 49 is mounted for movement in the dlrection indicated by the arrow 58 such that the relative positions of the cutter 54 and the ad~acent surface of the roll being built on a mandrel are maintained during the rewinding process. Thus, as the strip 16 passes between cutters 52 and 54 it will be slit into a plurality of narrower strips except at those areas where the strip 16 is contacted by the spring loaded satellite cutter 56.

_ 25 -, . ~ , . , , ~,. .:. ,. . . . , :~ -:: , , , :: . , :
... :, : : . . : - , : . . , . ~ - . : . .. .. .

The pressure of spring 60 is selected Lo b~ insu~ficient to force cutter 56 complctely througll the strip 16 during LhC pass of the strip between the cutters 52 and 54. However when the partlally cut areas thus produced in tlle strips are again cn~a~e~ by tbe satelllLe cutter 56, the now partially cut areas have been wcakclled sufficicntly ehat the cutter 56 may complete the cut lnitiatc~ at tl~e sliLting station ~-50. Because the distance between partially slit areas created by thc satellite cutter 56 is a function of the diameter of the cutter 54, thcrc is an automatlc synchronization which permits the partial cut are3s to ~ be presented precisely to the satellite cutters after rewilldinu of the strips has commenced.

; Coiling and uncoiling between milling and partial or to~al slitting can be avoided altogether in the practice of the lnvention.
In Figure 17 partial slitting is accomplished at cutter head 100 which carrles a gulte roll 102 and a pair of cutters 101 which, on a periodic ~; basis, partlally pre-slit the outfeed from the mlll prior ~o coilillg on thc msndrel 103. The head 100 may also carry suitable conventional stripper flngers (not shown) on the infeed side of the cutters, and guide boards (not shown) on the outfeed side immediately beyond the stripper fingers.
~2 The cutter head i9 moved on an inclined track 105 by cylinder ;06 as the coil io bullt to i~ts full dimension shown in phantom. The retracting cylinder 107 moves the entire slitting assembly out of the way on slideays 108 when lt is not to be used. ~le partially slit coil can be started cn the mandrel by a conventional beltwrapper 109 and can be supported and removed after winding by a conventionàl coil car and lift 110. The stand on which ehe slitter ls mounted may for example constitute the last stànd o a five-stsnd tandem cold mill. A like arran~ement may be used on a temper ~
constituting only a single stand, Instead of being partly slit, the roll ln Flgure 17 may be fully sllt by completlon of slittin~ by any of the means prevlously described as winding on mandrel ]03 occurs.

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In a presently preferred fo~l of the inve~ltlon, the ~Itacksll arc not allowed to rem~in with the increased overall tllickness as seen in Figure 5, but are illstead knocked down by passing the slit strips betwccll a pair of knock-down rolls spaced apart a distance approximately equal to or sli~htly less than or, lcss pr~ferably, greater than tl~e tllic~ness of Lhc sheet ~netal prior to slitting. The bridgc 48 is thercby caLIsc~ to partiall~ ~llear as the adjacent slit strips at tlle "tack" are brought back to level wi~h cacll othcr.
I bave discovered that in at least some if not many applications tlle dau~htcr - coils wlll wlnd with good tracking and no edge overlapping even in the absence of the tracking arrangements described earlier herein due to the "capture" upon winding of constraints imposed by the slitting rolls on the side edges of the taughter-coils-to-be, as previously mentioned.

,~
~; In one particular experimental set-up illustrated in Figures 18, 23, and 24 a steel coil 121 (Flgure 23) of .015 lnches thickness i9 unwound through guide 122, rotary 3-inch slitting cutters 123, and knock-down rolls 124 to a winding mandrel 125 driven by a motor 126 (~igure 18) through a suitable reducer and coupling. A control handle 127 operates through tt)e illustrated gear train to change the rotative position of an eccentric mounting for the upper cutter 123, thereby adjusting the , 20 spacing between the cutters. Each wheel of the lower cu~ter 123 ls , ~ :
provited with a flat as illustrated ln Figure 7, the flat being .125 ~- ~
, . . . .
inch from edge to edge and of a maximum "depth" (maximum chord-to-arc ~-spacing) of .006 inches from the cutter circumference.
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The cutters 123 each may include the spaced discs or cutters ~ proper 130, coacting pairs of which on the upper and lower cutter roll~
;~ sct to shear tt~e metal, and the strippers or elastomeric sleeves 131 arranged to push the sheared metal away from the shearing edges as the metal 'eaves the nip~ A crank 132 is provided for manually driving the upper cutter 123 durlng set-up.
, .~

., ' .
-~7-`` 1~89758 With tlle dimensions given, the tacking esLablislled by Lhc flats remains sufficiently connccte~ even aftcr passill~ t~-ro-l~h thc knock-down rolls to cause the slit strips to willd Logcthcr in~o n plurality of daughter coils 140 (l'igure 19~ consti~utinL, a parcll~ coil 141. In the illustrated examplc the two elldmost daugllLer coi~s 140a constitute edge trim strip and are therefore consider~bly nalrow-r than tlle other daughter coils. I have used pre-trimmed unwilld rolls in experiments, giving them narrow edge cuts to simulate edgc trimning.

When the handle 127 is shifted to lower the upper cutter 123, ~lO tacking ceases and the slitting is continuous, 1he slit strips continue to track nicely as tl-ey wind into he daughter coils being formed. As soon as a s1ight fluttering or looseness of one or both of the outcrmost or next-to-outermost daugllter coils is detected, the handle is reshifted to raise the upper cutter and re-establlsh tacking. Thc fluttcritlg or looseness immediately disappears as the slit strips are constrained by the tacking to wind together.

~ `igures 21 and 22 are schematic cross~sections of the slit strips immediately downstream of the knock-down rolls. Figure 21 shows a region of tacking, the bridges between the adjacent strips being shown as more or less sheared but not completely parted. Figure 22 shows a fu1ly s1it region.

:; :
~ 8ecause of tlle crown seen in Flgures 21 and 22, the edgeward ; daughter coils forming the parent coil 141 are wrapped more loosely ;~ than the more central daughter coils. However because the daughter coils are constralned to wrap togcther they all have the same number of turns per unlt length. The "tacks" are such that the connections , ... . . . . . . .

~ . ' .

`~ ~
` lQ89758 between adjacent daughtcr coils are contained en~ire]y be~ween tll~
front and back faces or surfaces of the shect metal. The ront or hack faces aee not uninterruptcd across the "tacks," as woul.d be tl,c c~sc if slittiu~ i were entirely discontinued at the connecting r~giolls The opl-osi.te edge faces of adjacent daugllter coils created by the s]iLting opcr~ioll cach have a continuous corner edge throughout the lellgtll o~ tbe dau~llter coils, including tlle "tacked" portions thereof.

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The "tacks" or connections between the slit strips may be establislled in such a manner as to seek only a minimal constraint to cause the slit strips to wind togetller. Thus in tlle above exaMple, when fluttering or looseness of any of tlle daughter coils is detected, the upper cutter 123 is not abruptly raised but instead the handlc 127 is shifted cnougll to initiate a minilllal degree of tacking wllicll is usually too weak to both survlve the knock-down bars.and hold tlle strips together until they wind on the mandrel 125. Sh~fting of tlle handle 127 is continued until the tacking is just strong enou~il to re-establish.the constraint of forcing the slit strips to wind together.
When this contraint.is established, the upper cutter may be maintained in its position or, preferably, it may again be lowered to repeat tlle -~-cycle. Such lowering may be gradual and may be conLinued only until the looseness or fluttering is again detected. This manually controlled .
system can obviously bc replaced by an autolllatic system wllicll in effect "hunts" back and forth between a condition of being just barely able .
to maintain tlle constraintand a condition of béing just barely unable to maintain th~e constraint.
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Instead of e~ploying the illustrated flat of a depth of .006 inches, I cotitempla~e ~mpl.uying coacting flats Oll the upper and lower cutters l?3, each .003 inches deep for a similar but more sytnmetric tackinr, .
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. -29-. ._ ~ . . ~ , - . ,, . ~ . . . . .

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1(~89758 action. In such case the upper and lower cutters 123 would be geared together for rotation to maintain the proper register of the flats. The cutters 123-are not geared together in the illustrated embodiment.
For better control of tacking strength as a function of roll adjustment, I propose to use shapes other than a flat. Thus in Figure 7a the relief ground onto the cutters by a suitable grinding roll is in the form of gullwings formed by a pair of arcs whose points of tangency with the circumference of the 3-inch diameter cutter are .125 inches apart.
The centers and radii of these two arcs are such that they intersect .006 inches below the roll periphery.
More preferably, two similarly configured reliefs can be provided on a pair of cutters geared to rotate together, each relief having an arc-intersect that is .003 inches deep, With these shapes, the cross-sectional area of the connecting bridges formed by the relief varies with roll spacing in a more definite~
manner, making ~for more precise control. With both rolls being relieved - with such a shape, as the cutters are brought together, the mirror-image 'gullwings" of the two reliefs increasingly overlap to provide a diamond ~shape of diminishing size which will finally disappear although presumably the degree of tacking necessary for winding constraint ceases before such point of disappearance is reached.

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~ _ 30 :~
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, ;
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' . . ': ::
: ~ ' ' -:' ' 1~897S8 I~ one of the upper and lowe~ cutters is advanced angularly relative to the other while they turn together with the reliefs in register, such advance has the effect of "tilting" the diamond shape. This tilt can be either "forward" or "backward" depending on the relative direction of the angular advance. Such relative angular advance can be accomplished by any conventional control means which allows a differential angular movement to be introduced between two counter-rotating rolls turnlng together.
The two cutters can be both moved toward and away from each other and advanced angularly relatively to each other for different tacking effects.
As increasing amiliarity with a given sheet material is gained, a pre-set degree of tacking may be selected. A feature of the invention is that the degree of cohesion between daughter coils can actually be modified, from parent coil to parent coil, by adjusting the strength and frequency of the tacks, as for example by adjusting the slitting cutters to make the cross-sectional extent of the individual tacks greater or less, and/or ad~usting the frequency of tacking or degree of intermittent operation. -In the apparatus of Flgure 3 a knock-down roll 35 may be provided ~; together with a similar roll underneath the strip. With the provision of the knock-down rolls, it wilI be understood that the configuration of the coil wound ` on mandrel 36 is simllar to coil 141.
In Pigure 17, knock-down rolls 111 may be provided immediately beyond the cutters 101.

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-lass7ss Instead o~ functioning as knock-down rolls, rolls such as 124 of Figures 18 and 23, and 35 of Figure 3, may be set by appropriate shims or the like (not shown) to a spacing about the thickness of the sheet material being slit, or preferably slightly under such thickness, and the slitting cutters may be set to slit continuously, I have found that, under at least certain conditions, when the slits pass under the rolls 124 or 35 following their formation by the slitting cutters, they are rejoined to accomplish non-periodic tacking. In one particular experimental set-up of the apparatus illustrated in Figures 18, 23 and 24 dead soft copper of .005 inches thickness is slit and passed between the rolls 124 which are shimmed apart by shim plates (not shown) of .004 inches thickness to give a nominal reduction of .001 inch or 20%. However any actual reduction is difficult to observe in terms of sheet width growth, and is not believed to be significant. The slits are tacked or rejoined by the rolling operation, and the connection appears to be stronger in the direction of travel than in a direction perpendicular to the sheet. The rejoining is not presently clearly understood and may be a pressure welding phenomenon or the like, and/or result from mechanical interengagement of burrs or the like formed by the slitting opera~ion. In Figure 22a I have schematically illustrated burrs as small curved lines at the tops and bottoms of the slits seen in Figure 22a, which is a schematic 20 cross-section of a sheet which has been non-periodically tacked as just described, although if burrs form part or all of the interconnection they may occur at other locations within the interfaces formed by the slits as well as or rather than, as shown, toward the outer extremities of the interfaces. Such operation as described is non-intermittent since the shims cannot be changed during slitting.
In Figure 26 I illustrate a modification of the apparatus shown in Figures 18, 23 and 24 which includes a control handle 127a which operates through a gear train, similarly to the handle 127, to change the rotative position of an eccentric mounting (not shown) for the upper roll 124, thereby adjusting the spacing between the rolls 124. Such handle can be shifted from a tacking position .. . .

- - ~ ' ' ' ':

.. ~ ' ~ , . , . ~. . .
..:...: .~.
' ~' . '' 1()897S8 at which the rolls 124 are faixly close together to a non-tacking position at which the rolls are spaced apart to thereby give an intermittent type operation.
To some degree, adjustment of tacking strength may be possible by ad~ustment of spacing of the rolls 124 through a range, from relatively strong at relatively close spacing to progressively weaker at progressively less close spacing.
The interconnections between the daughter coils such as the coils 140 are breakable either by unwinding such as that described in connection with Figure 13 or by simultaneous breaking away of all connections. In the experi-mental apparatus of Figures 18, 23 and 24, unwinding separation can be accomplished by removing mandrel 125 with roll 141 on it from the wind-up station, turning it end for end, and substituting it for the original unwind mandrel (for the original unslit roll 121) at the unwind statlon. A single edgemost daughter coil 140, or 140a if the original roll 121 was not pre-trimmed, is trained over a wedge finger 134 pivoted on a slide 135 (Figure 25) carried in a frame 136 (Figures 18, 23, 25) and through any ~uitable guide such as the knock-down rolls (the cutters may be moved apart if in the way). The leading ends of the remaining daughter coils 140 are taped down to the parent coil 141 to prevent them from flapping and snagging. The wedge finger 134 may be thinnest at its inboard side and in-crease in thickness toward its outboard side, as indicated by the flare of the stem portion of the finger seen in Figure 25, to provide good lifting or prizing ; action. Unwinding may be done manually by pulling on the unwinding strip. As the daughter coil unwinds, the slide 135 allows the finger 134 to follow the diminishing periphery. A slight drag is applied to the parent coil 140 to prevent it from overrunning. The unwinding strip breaks readily and clearly from the parent coil. Subsequent daughter coils can be similarly unwound by shifting the frame bracket in which the slot 136 is formed laterally by the ~idth of a daughter coil in order to establish the proper lateral position for the finger 134. The bracket is held in adjusted position on the fixed frame by the illustrated hold-down bolts.

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I have found that i~ many cases a priZing device such as wedge finger 134 is unnecessary and the daughter coils will unwind readily in responseto an unwinding pull, even that imposed only by the unsupported weight of a just-unwound reach or fall of daughter coil material~
As previously indicated, the constraints on the strips during coiling that can be accomplished by the invention provide flat interfaces between daughter coils despite almost inevitable cambering of the sheet material and the slit strips formed therefrom. The camber is accommodated by variations in tight-ness of wrap as schematically illustrated in Figure 28. Figure 27 shows on a reduced scale one of the strips resulting from uncoiling one of the daughter coils of Figure 28, with camber clearly present. Nevertheless, the interfaces between daughter coils are substantially planar as seen in Figure 28. Thus, although in a general sense "tacking" according to the invention causes all daughter coils to wind together at the same uniform lengths per unit turn despite variation in their thicknesses, there are specific slight variations from one daughter coil to the other of turns per unit length, such variations being a function of the degree of camber being encountered. More precisely, there are very slight differences in tightness of wrap of the opposite side edges of each daughter coil, beyond that incident to sheet crowning, just sufficient to accommodate the camber in each coil. It appears that the invention can force these slight variations in turns per unit length and these slight differences in tightness of wrap of opposite side edges of each daughter coil to occur to just the extent necessary to accomplish the substantially planar interfaces between daughter coils.
Figures 27a and 28a illustrate, even more schematically, the situation when the camber is serpentine or reversing, as may be caused for example by slight variations in the feed to the slitting cutters. In Figure 28a the interfaces between adjacent pairs of daughter coils are flat despite the camber, and the two side edges of each daughter coil and of the parent coil in-crementally along their lengths differ from each in tightness of wrap, ' ` ' :
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lV89758 beyond the differences incident to crow~ning of the sheet ~rom which the coils are formed, as a function o~ the deg~ee and d~rection of camber of the strip material incrementally along its length. Figure 27a shows on a reduced scale the development of the coil shown ln ~igure 28a, illustrating the serpentine or reversing nature of the camber. In such a situation the outside ends of the parent coil may be very uneven, as seen in Figure 28a, yet the interfaces between adjacent daughter coils are flat, as shown.
Figure 28a also illustrates parts of the disc-like coils of scrap, indicated at 34a, that can be used to protect the edges of the parent coil in -~
trans-shipment, as previously mentioned, and that can be broken off or unwound from the parent coil either prior to trans-shipment or by the final user. Such discs of scrap are not specifically illustrated in Figure 3 due to the small scale thereof.
The outer ends of the parent and daughter coils may be secured against unwinding by being taped down to the next run of material. For trans-shipment it may be desirable to band the parent coil through the coil core say with three bands spread 120 degrees apart. The disc-like coils 34a of scrap or edge trim protect against the bite of the banding.
Although the outside edges of the edge trim coils may be quite irregular, as shown, the internal interfaces are flat, as also shown in Figure 28a.
A slitting line embodying novel self-threading concepts is illu-strated in Pigures 29 and 30. The pass line is relatively constantly horizontal.
A sli~ter carriage 176 is vertically movable on the posts 177 by a cylinder 178, the carriage being further constrained in a well-known manner against cocking to one side or the other by the illustrated fixed racks and coacting linked pinions carried at each side of the carriage.
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:: . ~: : :... , ' : ' . :
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The coil stands are driven by DC motors which can also act as back drag generators. The leading end of the off_feed coil 179 is slowly driven forward to be initially peeled by a retractable peeling member 180, and to be guided by a fixed rise surface 181 to pinch rolls 182. The lower pinch roll is on a fixed mounting while the upper one is mounted on carriage 176 which is raised slightly and then lowered to accept and then tightly engage the leading end to the slitter cutters 184 of the tacking type contemplated by the invention.
An auxiliary slitter drive including a cylinder (not shown), a vertically moving rack 185 and a spur gear 186 enclosing a one-way overrunning clutch (not shown) powers the slitters, the "thread-ing" stroke of the rack 185 being just sufficient to advance the leading end, which is now "tacked" as will be seen below, from its point of first engagement with the slitters through the illustra~ed knock-down rolls and to the take-up mandrel, and into position as shown to engage or be readily brought into engagement with the lip 187 which has been formed in a conventional manner by the initially collapsed segments of the take-up mandrel.
The mandrel is then expanded to cause the lip 187 to grip the "tacked" leading end to complete thréading.
The flats (not shown due to small scale) on the slitter cutters are positioned to place "tacks" at or very near the leading end of the strip when it first engages and is driven through the slitter cutters. This position-ing of the flats may be automatically accomplished by any suitable means, such as an index cam (not shown) associated with one of the slitter cutters and adapted to control a solenoid to deactivate the advance of the actuator for the rack 185 at the proper position during an "indexing" stroke prior to the "threading"
stroke previously described.
In the illustrated apparatus, the handwheel 188 may actuate a gear l mkage (not shown) to control spacing between the slitter cutters 184 and thereby control the depth of tacking and to also perhaps only apply tacking inter--~mittently.
~ 36 -.

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~0~975~3 As slitting p~oceeds, a microswitch or other sensor (not shown) at corner 189 on the slitter carriage senses buildup of the coll on the take-up mandrel and actuates cylinder 178 on a demand basis. The carriage 176 thereby continues to rise during the slitting operation, and the pass line continues to be generally horizontal until slitting is completed.
The off-feed coil is originally carried onto its mandrel by the coil car illustrated in Figure 30.
The ready threading just described is to be contrasted with the difficulties of setting up for conventional slitting, particularly the necessity to properly start, thread and clamp to the mandrel each separate strip being slit.
An experimental breakaway device for simultaneously breaking away all the connections of a daughter coil is schematically illustrated in Figure 26.
A parent coil is clamped on a frame 151 by a clamping member 152 releasably fixed to the frame at parting line 156 by clamping bolts or other clamping fasteners (not shown). The endmost daughter coil is received on a mandrel 155 which is initially aligned with the open core 150 of the parent coil. The mandrel 155 is eccentrically mounted in the frame lSl and has a squared end 153 which receives a wrench 154. Turning the wrench turns the mandrel 155 in its eccentric mount-ing and twists the endmost daughter coil relative to the ad~acent daughter coil, causing the endmost daughter coil to break away. The break is clean and the points of former connection between the coils are barely discernable, if at all.
To break off a succeeding daughter coil, the clamp is loosened and the parent coil is advanced to the left by the width of one daughter coil and reclamped.
A breakaway grab device such as illustrated in Figures 32 and 33 can be utilized by the end user of the pre-slit parent coil in a manner that - : ~ - : - - .
. ,~ - '' -. .: . ~ . : , :' :, ,: . . . : . -can be more ef~icient than conventional practice and require little change from conventional practice in utilizing ordinary handling equipment such as cranes or lift trucks to transport and position individual co~ls broken away from the parent coil. The illustrated grab includes an upper frame 161 which includes a suspension eye 162, a slideway 163 and a yoke 164. An upper gripping strap 165 of somewhat flexible material such as a flexible steel strap is pivoted on small stubs carried at each end of the yoke 164 in the manner shown.
: . ~ lower frame 166 includes a slideway 167 and an arcuate lower gripper 168. The upper and lower frames slide with respect to each other along a slideway 169. A clamping linkage including the motor 170 and screw 171 is associated with a cIamp drive frame 172 received in the slideway 169 and a - . screw nut 173 received in the slideway 163;
~ . The device may be suspended from a crane in the manner shown.
,~. To break away a daughter coil the member 168 is slipped into the coil and under : the end~ost daughter coil with the strap member 165 positioned ~ust beyond the . endmost daughter coil and over the next daughter coil, so that the members 165 and 168 engage the coil on opposite sides of the plane of the interface 174.
The motor 170 is then actuated to close the clamp whereby the endmost daughter ; . coil breaks away but rests on the member 168 with the outer side face of its ~ upper half perhaps lightly engaged or at least retained by slight interference with one side of the strap member 165. The separated daughter coil can then be transported to its particular place of use by the crane and can be released by actuating the mo~or 170 to open the clamp to the point where the strap 165 no -longer.interferes with.the outer side face of the daughter coil.
:~ -. - The slideways 163 and 167 all~w the clamping linkage to be ad~usted ; laterally for accommodation of daughter coils of different widths, since it ~: - ' ` .

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is generally desirable to position the linkage as close as ~ossible to the endmost daughter coil prior to b~eakaway.
Instead of or in addition to the eye 162, mounting brackets (not shown) can be provided to fix the frame member 161 or 166 to the lifting member of a lift truck. Or any special carriage or the like ~not shown) may be provided for the grab.
Another form of grab is shown in ~igures 34 and 35. A pair of clamping members 191 and 192 are shaped to penetrate the core of a parent coil and engage different segments thereof. Member 191 engages the coil at arcuate 10 face 193 and member 192 engages the coil at arcuate face 194. Members 191 and 192 may be tapered forwardly as shown to aid in guiding the insertion of the grab. The members are urged apart by the illustrated hydraulically powered frustro-conical wedging member 196 against the biasing of springs associated with draw rods or bolts which guide members 191 and 192 in their relative motion in the manner illustrated.
A stop member 197 defines the depth of penetratlon of the grab, and its position may be ad~usted along a marked scale (not shown) by loosening and retightening a tie-bolt in a T-slot, as illustrated, to thereby set the depth of penetration of the grab according to the thickness of the daughter coiLs.
Surfaces 193 and 194 terminate in slightly spaced relationship from each other so that they may be spaced slightly to each side of the inter-face 198 between the adjacent segments they are grabbing, as shown in Flgure 34.
This reduces the criticality of the magnitude of the depth of penetration of the members 191 and 192.
Means (not shown) is provided to fix the back end of the member 191 to the lifting member of a lift truck, or to suspend it from a crane or mount it on a special carriage for the grab.

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1C~89758 Nhen the endmost daughter coil is broken off by expansion of the members 191 and 192, this coll remains supported on the surface 193. At this point the grab may be slightly contracted and backed out of the core far enough to clear member 192 from the daughter coll which it engaged. The members 191 and 192 may be then expanded again, to a further degree, until the relief surface 195 engages the core of the broken off daughter coil. The coil is now securely grasped and may be tilted in handling, if desired.
It may be noted that when a daughter coil is unwound from the parent coil, rather than being broken away as just described, the unwinding may be arranged to give a spreading action whereby the path of movement of the separating strip has a vector component parallel to the roll axis. (One example of such an arrangement is shown in ~igure 13 and involves use of the prizing : ~ blade 91.) Movement along such vector cannot be accommodated by flexing of the strip material around the axis of the roll but rather is stiffly resisted by reaction forces acting parallel to the axis and to the surface of the strip material. Unwi~ding arrangements involving a separating movement with such a vector component therefore can be very effective in subjecting the tacks to concentrated tensile stresses for good breaking action. In some instances this can be accomplished by gravity alone, as when a starting end of an endmost daughter coil is dropped from the lower end of a parent coil which is tilted toward a vertical position so that the starting end continues to unwind by its own weight. I have unwound hand-held experimental coils in this manner, allow-ing the endmost daughter coil to rapidly unwind in a falling helix and accumulate as loose strip on the floor, with the remainder of the parent coil remaining intact and the exposed side of the next-to-endmost daughter coil remaining a smooth , - 40 -'~. : -.
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1~8g7S8' and well-defined surface.

It may also be noted that the compactness of the slittlng line contemplated by the present inventlon increases t~e practlcality of shleldlng the fast-moving sllt edges for the protection of the operator (although no such shielding is shown in the drawings). This is therefore one respect in which the invention offers substantial safety advantages.
: ' ' From the above lt will be apparent that the present inventlon provldes a fresh approach to the solutlon of problems assoclàted wlth conventional slitting ope~ations.

:.
- 10 Whlle the methods and forms of apparatus and constructs hereln described constitute preferred embodiments of the invention, ie is to be understood that the invention 19 not llmitet to these precise methods snd forms of apparatus and constructs, and that changes may be made therein wlthout departlng from the scope of the inventlon.

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Claims (37)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of shearing an elongated web of sheet metal by opposed rotary shearing cutters into a plurality of laterally spaced, elongated strips having continuous, oppositely facing, frangibly interconnected side edges defining uninterrupted parting lines between adjacent strips, comprising the steps of:
a) passing said web between said rotary cutters;
b) maintaining the surface of said web contiguous with the edges of said cutters; and c) causing the edges of said cutters to penetrate the surface of said web over the full circumference of said cutter edges, said penetration being to a point short of severance over at least a portion thereof to produce a residuum of unsevered metal interconnecting the oppositely facing side edges of adjacent strips.

2. The method as recited in claim 1 including the step of shearingly offsetting the metal of said web in opposite directions out of the plane thereof on opposite sides of said parting lines.

3. The method as recited in claim 1 in which penetration of the cutting edges to a point short of severance occurs intermitten along said parting lines.

4. The method as recited in claim 2 including the step of urging said interconnected strips back into the plane of said web without severing said residuum of metal.

5. The method as recited in claim 4 in which the interconnected strips are urged back into the plane of said web by passing said web between opposed rollers.

6. The method as recited in claim 5 including the step of constraining said rollers against separating more than the thickness of said web.

7. The method as recited in claim 1 including the step of moving at least one of said cutters with respect to said web to produ?
said residuum of unsevered metal.

8. The method as recited in claim 1 including the step of providing edge relief in at least one of said cutters to produce said residuum of unsevered metal.

9. The method as recited in claim 2 including the step of at selected locations along said parting line reducing the degree of engagement of at least one of said cutter edges with said web to reduce the amount of relative offset of the metal on opposite sides of said parting lines to an extent less than that required to effect severance of said sheet metal whereby the residuum of unsevered metal is produced.

10. A method of shearing an elongated web of sheet metal by opposed rotary shearing cutters into a plurality of laterally spaced strips frangibly interconnected along uninterrupted parting lines between adjacent strips comprising the steps of:
a) passing the metal web between said rotary cutters;
b) continuously maintaining the surfaces of said web contiguous with the edges of said cutters to form by the cooperative engagement of said cutter edges with said web a step in said sheet metal along said parting line to an extent sufficient to cause said sheet metal to break apart;
c) maintaining the so-formed strips of sheet metal in contiguous side-by-side relation; and d) pressing said strips along said parting line to form a longitudinal joint between adjacent strips.

11. The method as recited in claim 10 in which pressing is accomplished by passing said web between opposed rollers.

12. The method as recited in claim 11 including the step of contacting said web intermittently with said rollers.

13. The method as recited in claim 1 including the step following shearing of winding said interconnected strips into a coil.

14. The method as recited in claim 10 including the step following shearing of winding said interconnected strips into a coil.

15. The method as recited in either one of claims 13 or 14 including the step of completing separation of the strips along said parting lines following winding thereof into a coil.

16. The method as recited in either one of claims 13 or 14 including the step of maintaining the wraps of corresponding interconnected strips in radial alignment during winding.

17. The method as recited in either one of claims 13 or 14 including the step of controlling the degree of sag in said strips between said slitting cutters and said coil by varying the spacing between said residuums of unsevered metal along said parting lines.

18. The method as recited in either one of claims 13 or 14 in which said web of sheet metal varies in thickness across its width including the step of constraining said strips to wind together at a uniform length per unit turn.

19. The method as recited in claim 13 in which said web of sheet metal varies in thickness across its width including the step of constraining said strips to wind together at a uniform length per unit turn said constraining step comprising regulating the spacing between said residuums of unsevered metal along said parting lines.

20. The method as recited in claim 13 including the step of detaching individual strips from said wound coil by concurrently fracturing the residuums of unsevered metal in the parting line between adjacent strips.

21. Slitting apparatus for shearing an elongated web of sheet metal into a plurality of laterally spaced, elongated strips having continuous, oppositely facing, frangibly interconnected side edges defining uninterrupted parting lines between adjacent strips comprisi a) a pair of cooperating rotary slitting cutters operative to engage the opposite surfaces of said web in shearing relationship to force the metal downwardly on one side of each of said parting lines and upwardly on the other side thereof whereby, along the parting lin a step is formed in the web of sufficient extent to cause the web to break apart along the parting line, and b) means for intermittently adjusting the position of the slitting edge of at least one of said cutters with respect to the surfaces of said web to reduce the height of the formed step to a finite extent less than that required to cause the web to break apart thereby to produce residuums of unsevered metal interconnecting the appositely facing side edges of adjacent strips.

22. The apparatus as recited in claim 21 in which said means comprises means for shifting the cooperating cutters with respect to one another.

23. The apparatus as recited in claim 22 in which the means for shifting the cutters relative to one another includes means for mounting at least one of said cutters eccentrically on its axis of rotation.

24. The apparatus as recited in claim 22 in which the means for shifting the cutters relative to one another includes means for vertically displacing one of said cutters with respect to the other.

25. The apparatus as recited in claim 24 including cam means operative to displace one of said cutters with respect to the other.

26. The apparatus as recited in claim 21 in which said means comprises a relief formed in the cutting edge of at least one of said cutters, said relief being of a radial extent less than the thick of said web of sheet metal.

27. The apparatus as recited in claim 26 in which said relief is a chordal flat formed on the periphery of said cutting edge.

28. The apparatus as recited in claim 26 in which said relief is a gullwing notch formed on the periphery of said cutting edge.

29. The apparatus as recited in claim 28 in which said gullwing notch is defined by convex, generally cycloidal flanks.

30. The apparatus as recited in claim 21 including means downstream of said cutters in the material flow sense for urging the so-formed step back into the plane of said web without severing said residuums of unsevered metal.

31. The apparatus as recited in claim 30 in which said urging means comprises a pair of oppositely spaced knock down rolls operativ disposed to engage said web each on opposite surfaces thereof.

32. The apparatus as recited in claim 31 in which said knock down rolls are oppositely spaced a distance no greater than the thick of said web.

33. The apparatus as recited in claim 21 including means for winding said slit web of sheet metal into a coil construct of frangibly interconnected strips.

34. The apparatus as recited in claim 33 in which the wraps of coiled strips are radially aligned throughout the thickness of the construct.

35. The apparatus as recited in claim 33 including means for completing separation of said strips following winding the web into a coil construct.

36. The apparatus as recited in claim 35 including a prizing beads operatively disposed to the respective parting lines for severing said residuums of unsevered metal upon uncoiling of the respective strips.

37 The apparatus as recited in claim 35 said means comprises a satelite cutter operatively disposed to the respective parting line for severing said residuums of unsevered metal prior to uncoiling the respective strips.