US1917630A - Apparatus for slitting metal sheets - Google Patents

Description

July 11, 1933. H. K. BAKER APPARATUS FOR SLITTING METAL SHEETS 4 Sheets-Sheet 1 Filed Aug. 28, 1931 INVENTOR He rbefiKBa/(er.

NEYS

W ATT R July 11, 1933. K, BAKER 1,917,630

APPARATUS FOR SLITTING METAL SHEETS Filed Aug. 28, 1931 4 Sheets-Sheet 3 L a4 55] Q 4% r 50 54 INVENTOR HerberfKBaker. BY

% ATTOzNEYS.

Patented July 11, 1933 Lanai-312T x. BAKER, or n'n'rnoi'r, raloaroen APPARATUS FOR- SLITTTING IVILETAL SHEETS Application filed August 28, 1931. Serial No. 5.593%

This invention relates to apparatus for slitting metal sheets. More particularly, the invention is concerned with reciprocating H press mechanism having punches mounted therein and arranged for cooperative slitting of metal sheets or blanks particularly of the type employed in the production of expanded metal lat-hing. v

Generally considered, the present invention has in View increasing speed (it production, enhancing the strength and life of various parts employed and, in addition, simplilying; the mounting, original fabrication and replacement of the slitting part-s.

P lil'ore specifically, this invention contemplates the use ot a plurality or multiplicity of cooper: ting slitting punches arranged in groups i a each of the cooperating press memr hers to inwrleave upon actuation thereof. It sl'ionld here he noted that Various ditliculties and disadvantages have been encountered in As a result, the requently become i punches not .iirperl and broken.

T hi s disadvanta has materially held back or hindered the development and use of slitti mechanisms employing large numbers 11;: elements or punohe It apot course, that ii is desi ,ie to emu a iparatus having a large number-oi? punches mounted therein for the reathis materially enhances speed of production.

The present invention has in View overcoming disadvantac'es encountered hereto- K, tore such as those ust refer ed t above by the provision of a slitting )unch arrangement which lends itself very readily to shaping" ortapering of the cutting edges 01 the punches themselves in such manner as to pro vide a shearing action in the production of the slits. v.

To further bring out the clniracterof the novel features here referred to,fattention is called to the fact that. heretofore in this art, in most instances Where was desired to employ a machine having a multiplicity of sl ng punches, the machine included a plurality of groups oi slitting elements arranged for cooperative slittingot blanks by relative reciprocation, the slitting elemen s each be ing notched or recessed in a cutting; edge thereof to provide for,interruptimi of the elongated slit which would otherwise be produced. The plurality of sli ting elements of this type heretofore employed were arranged in groups, in the reci 'irocating press members, to cooperate with each other and produce slits in'the blanks atone edge only (the notched edge) of each element. ,Another arrangement of suchslitting punches heretofore adopted is that in which each element provided Withtwo slitting edges only one of which Wasnotched or recess and in Which the cooperating elements were arranged to; interleave so that the notched edges of those in one press member cooperated with the plain edges of those in the other press men'iher, and Vice t ers In both of these prior arrangeruents it is very difficult itnot impossible to machine or shape the cutting edges of the punches so that they will provide a shearing; act-ion upon actuation of the press. indeed, as a practical matter, no attempt was made to provide such shearing action and, in consequence, the prior arrangements r sulted in tremendous inipacts or shocks to the press in ther l and to the punches in particularliy virtue or? the fiat and materially extended surface co tact v t e punch cutting edges with the blanks being s i This condition, of course, is mo 1 SGllOli Where the slitting apparatus includes a series or plurality of punches disposed lengthwise of the feed of the ap liaratus as well as transversely thereof. The present invention has in view the elimination or, at least, the material reduction of difficulties of this character as will appear more fully as this discussion proceeds.

Another point which should be observed in this connection is the fact that replacement or regrinding of the slitting punches is the major item involved in the upkeep of the apparatus so that, in accomplishing the foregoing projects, the present invention results in material reduction of maintenance or upkeep costs.

With the foregoing in mind the present invention contemplates the use of a multiplicity of slitting punches arranged or mounted in two cooperatingpress members in position to interleave upon actuation of the members, each slitting element having a pair of slitting edges which are spaced from each other a distance greater than the width of the strands ultimately to be produced. That is, each slitting punch is machined to provide a slitting or cutting edge at each side of a flattened portion of the punch element, this flattened configuration, in the preferred arrangement, also being extended throughout the entire punch, so that each element takes the form of a parallel sided plate member which may readily be fabricated or machined from suitable tool steel sheets. Still further, in accordance with the preferred embodiment, each punch element is of width or thickness substantially equal to twice the width of the strands to be produced, and the spacing between the punches of each group is of similar width to provide for the interleaving of cooperating elements of similar configuration and dimensions.

The punches of the present invention are also mounted in the press members so that their cutting edges are slightly inclined or obliquely set with respect to the direction of feed of blanks through the apparatus, the result of this being the productionof similarly inclined series of slits in the blanks' With the length of the feed steps, the inclination of the punches,,and the width of the punches properly relatively arranged and proportioned, the strands are produced by production of one group of slits (as a result of one press movement) and the subsequent production, by the same sets of punches, of additional slits interleaving with or extended partially between slits produced by the first press movement. The manner in which these operation are effected will be more ap parent, of course, from a consideration of the following description of the accompanying drawings.

In any case, with slitting punches arranged and configured as brought out above, the punch elements themselves may much more readily be shaped or rounded off at their cutting edges to provide for a shearing action.

In addition to the much more sturdy and long lived construction (resulting from multiple width punch elements), the present invention further contemplates greatly simplifying and facilitating the construction of the punches to provide for a shearing action.

he nature and advantages of this feature will be still more apparent upon consideration of the fact that in accordance with the present invention the slitting punch elements are multiple in character. That is, each slitting punch element is not only of flattened plate-like configuration but also is cut out or recessed at its working edge to provide a plurality of independent and spaced punch portions. lVit-h punches of this character arranged to interleave upon actuation of the press members and to form slits at each side thereof, each individual punch portion of said multiple elements may conveniently be tapered oii toward the ends of its Working or cutting edges to provide for the shearing effect ab ve referred to. As an additional advantage, it should be observed that the punch portions of these multiple elements may very conveniently be machined, at least as to certain faces thereof,togetheras a unit. The work and time involved in the production or regrinding of the elements, therefore, is reduced to a minimum.

Multiple punch elements of the character above described are still further advantageous in materially simplifying the mounting arrangements necessary in securing the various groups thereof in the press members. In this connection it should be borne in mind that where the. punches are multiplied lengthwise as well as transversely of the feed of the blanks through the apparatus, the mounting and securing of the various parts and elements is very considerably complicated. With applicants multiple punch elements, however, the number of individual parts, which must be placed and secured within a certain group of parts in the press, is reduced to a minimum, it being borne in mind that, according to this invention, a single base portio, for a plurality of individual and sepa rated effective punch portions of each element, is all that is necessary for the purpose of obtaining the necessary backing in the press member as well as for the purpose of fastening or securing the part in its proper position.

Another feature of this invention which should here be brought out is involved in the use of a novel stripper mechanism for the punches. Before considering the objects and advantages of the particular stripper mechanism here referred to, attention is called to the fact that where multiple slitting is being carried out, particularly where a multiplicity of slitting punches are arranged {mm-"11+ lengthwise as well as transversely of the feed of blanks through. the apparatus, Very effective or complete stripping action is new" increased engagement of the blanks. been very difiicult heretofore to provnh cicnt stripping action for press K160i? in vhich the punches were multiplied lei l wise as well as across the feed, espcci the production of narrow stranded mesh such as that now commonly employed. l cause of this extended engagement of punches with the blanks. This (little arose by virtue of the fact that it was possible to dispose stripper members in the press to engage the blanks only between separated groups of punches and'to the front and rear of such groups of punches; ()bviously, such an arrangement, especially where the punches are arranged in multiple lcnsthnise of the feed, left very large areas, defined by the dimensions of the groups of punches, e tirely without adequate stripping action.

However, where punches of multiple thickness or width are employed, the spaces between adjacent punches in each group are of sufiicient dimensions to permit the insertion of disposition of stripper ligaments or fingers therein. This, of course, results in very complete or thorough stripping action between the punches themselves as well as in areas surrounding the groups thereof. The present invention, therefore, materially reduces di'fiiculties heretofore encountered in the stripping of the blanks from the slitting; punches in a machine in which the punches are multiplied lengthwise as well as transversely of the feed. As a further result, warping of the blanks, sticking: thereof on the punches, and also irregularities in feed, are reduced to a minimum.

Another advantage of substantial importance lies in the fact that, in addition to the more accurate feed provided, any inaccuracies, which may 0001. from time to time, produce only relatively slight variations in the width of the ultimate strands. The reason for this is the fact that where multiple width punches are employed, an inaccuracy in feed is distributed, so to speak, over a plurality of strands, it being borne in mind that the Figure 2 is a vertical sectional view through the pair of press members menses Figure is an tails of the slittin punch arrangements;

enlarged view taken sins: la ly to Figure 9 but. illustrating certain stantially' as indicated by the section line Figure -l is a view of two groups of slitting v punch parts mounted in the loweripress nembar, this view being taken as indicated byfthe line l l on Figure parts in top plan;

Figure 4/: is a view also taken substantially as indicated by the line i l ofFigure 3 butshowing punch elements, tion, mounted in the upper press member;

0 and showing the punch in horizontal sec- Figures 5 and 6 are side or face views of iagrammatic ilof portion of a blank wl'iich has also including various markings,hereinafter I explained, to show the manner in wl rious slits are produced at the succes era ions of the press.

We oplicfore considering thedrawings in detail,

attention is first called to; the fact that the, present invention is in the nature of an improveminit on the method zmdapparatus described and claim d in my copending application, Serial No. 356,331, filed April 19th.

' neferri p er and .,eneral y by the reference numerals 10 and The base member '11 is i rerpectively. eferabl stationarily mounted while the lower press members are indicate:

iprocation on the posts 12-, guide apertures being; provided in the upper member for "his purpose. I

vBoth of the press members are somewhat similar as to their general arrangement and as to the provision therein of a large groove extended transversely of the-feedthrough the apparatus for the purpose of receiving and l'nounting thevarious cooperating groups of slitting punches. These grooves or recesses are clearly illustrated in Figure 2, and as here seen, each one ofthem is provided with a pair of cooperating, wedge members 15 which may suitably be employed as a means of adjusting the height of the punches within their respective press members. A backing plate 16 may also be dis .pper i ember 10 is arranged-for vertical refirst to Figures 1, Q and the posed'in each press member at the outerface Y of the ad'ustin wed 'es 14 15.

1 b h The punch elements themselves, as most clearly seen in Figure. 1, are'arranged in two series extended transversely of the feed through the apparatus, this feed being in the direction indicated by the arrows 17 in Figures 1, 2 and 3. These series of punches, furthermore, are spaced 2 from each other lengthwise of the feed as clearly illustrated in Figures 1 and 2 and, in addition, include groups of punch elements which are spaced apart from each other transversely of the feed. The general arrangement, still further involves a disposition of all the slitting punch elements angularly or inclined with respect to the direction of feed. Finally, as to the general layout, attention is called to the fact that all the punches in each series are inclined in one direction with respect to the feed While those in the'other series are inclined in the opposite direction. Various advantages and objects of this punch distribution and disposition will be considered more in detail hereinafter.

Turning now to a description of a single group of slitting punches, particular reference should be made to Figures 3, 4: and 40. A group of upper punch elements is made up of two different punch parts together with inter-spacing members. The two types of punch elements employed in each upper group are indicated by the reference characters 18 and 19, these parts being shown more or less in detail in Figures 7 and 8.

In the first series of punches to engage the blank in its movement through the apparatus, as aboveenoted', the inclination of the punches is all in one direction, this inclination being obtained by the use of a punch holder or positioning structure 20 (see Fig. 1 illustrating the upper press member). It will be understood, of course, that a similar holder member 21 is employed for the lower press member as clearly indicated in Figures 2 and 3. Since the upper and lower members are substantially the same in essential respects, a description of one of these parts only will be necessary for a complete understanding of this invention. Referring then to Figure 1 in particular and also to Figures 2 and 3, it wil be seen that the holder device for the upper press member is provided with two series of'apertures or cutout portions 22 and 23, those indicated at 22 being arranged to receive the groups of punches which are inclined in one direction, and those indicated at 23 being arranged in like manner to receive the oppositely inclined punches. This holder, of course, is securely fixed to the body of the press member as by means of bolts 24. I

The punch arrangement or grouping in each one of the apertures 22 and 23 is entirely similar except for certain inversions of parts which is necessary in view of the opposite inclination of the punch parts as between thosemounted in the apertures 22 and those mounted in the apertures 23. In Figures 3 and 4a I have illustrated the punch grouping which is employed in one of the apertures 22 and, in making reference to these figures, as well as to Figure 1, it should be noted that each aperture 22 has mounted therein two groups of slitting punches, these groups being spaced from each other by means of wedge devices 25 and 28. The device 25 is preferably mounted substantially fixedly within the aperture 22 while the wedge 26 is of somewhat smaller overall length in order to provide for relative movement thereof with respect to the member 25 and thus produce a tightening or wedging action againstthe groups of punches which are disposed at opposite sides of the cooperating wedges. An adjusting bolt 27 threaded into the holder 20 and bearing against the large end of the wedge 26 serves to eiicct this tightening operation. A lock nut 28 may also be employed to prevent loosening of the parts.

As noted above, each one of the upper groups of slitting punches includes a plurality of punch elen'ients 18 (see Fig. 7) and 19 (see Fig. 8). Each punch part 18 has a base portion 29 which is adapted to bear against the backing plate 16 and at its working edge this punch part is divided or split into a plurality of punch portions proper indicated at 30. Furthermore, as clearly indicated by comparison of Figures 3, 4c and 7, these elements 18 are generally of flattened plate-like configuration so that they may readily be cut or machined from tool steel sheets or the like. The other type of punch element (19) which I employ in each upper punch group is quite similar to that illustrated in Figure 7 but, as shown in Figure 8, this part has a base 31 and a lesser number of separated punch portions proper 32. In the particular embodiment herein disclosed each element 18 is provided with three punch portions 30 while each one of the parts 19 has only two, these two being disposed toward one end of the working edge of the punch, the other end being cut away as indicated in Figure 8 at 33. As seen in various of thefigures, each one or" the punch portions 30 and 32 is provided with tapered o'll' cutting edges 34734: to provide a shearing action during the actual cutting.

The relative arrangement of the parts 18 and 19 in each punch group will be apparent trom inspection of Figures 1 and 4a. Here it will be seen that I have employed a group of two elements 18 arranged side by side and spaced from each other as by means of spacers 35 (see Fig. 1). Each one of these groups further includes a punch element 19 arranged at opposite sides of the adjacent pair of elements 18; The punch parts 19, however, are reversed in position at the opposite sides of each group so that their cutaway portions 33 fall diagonally opposite to each other across the group.

From inspection of Figures 1 and etc it will be apparent that each one of the two groups of punches mounted in the apertures 22 of the upper press member are arranged in exactly the manner above outlined, this feature being of importance from the standpoint of assembly as well as in making replacements, for example, after resurfacing or grinding the cutting edges. Spacer parts 35, of course, are also disposed between the adjacent elements 18 and 19 in each group.

As to the groups of punches which are mounted in the holder apertures 23 (see Fig. 1), it is to be observed that the arrangement is quite similar except that the apertures 23 have side walls which are inclined in the opposite direction in order to set the associated punches in a similarly oppositely inclined manner. In view of this opposite inclination, of course, the side punch parts 19 of these groups are inverted or reversed with respect to their positions in the groups mounted in apertures 22. That is, inv the groups mounted in apertures 23. the elements 19 have their cutaway portions 33 arranged oppositely to the diagonal arrangement thereof in the groups first described (see Fig. 1) These latter groups, however, are similarly secured within the apertures 23 by means of wedge devices 25 and 26 and adjusting bolts 27.

Turning now to the groups of punches mounted in the lower press member 11, it is noted, in the first instance, that the general arrangement of the parts is entirely similar to that described above, including the manner in which the two groups of punches are spaced from each other and secured within the apertures in the holder 21 of the lower press member. A detailed showing of these parts as applied to lower punch groups, therefore, is not included in this disclosure as it is not believed to be necessary for complete understanding of the invention.

In Figures 5 and GI have illustrated the two types of punch elements which I prefer to employ in the lower groups, these elements being indicated generally by the reference numerals 36 and 37. The parts 36 may be substantially rectangular or square in outside configuration and are arranged with their base portions 38 bearing against the backing plate 16 of the lower press member. The working or cutting edges of the parts need not be interrupted or separated into portions such as those illustrated at 30 and 32 in Figures 7 and 8, but may be left entirely' straight throughout the length thereof as indicated at 39 in Fi ure 5. With respect to the parts 37, it is noted thatthe working portion or edge is here substantially cut back as indicated at 40 in order toleave only a relatively short cutting edge portion 41. These parts are also arranged with their bases 42 adjacent the backing plate 16.

The arrangement of the parts 36 and 37 is similar to that described above in connection with the parts 18 and 19. In this instance, however, I employ a central groups,

of three punches 36' (see Fig. 4) at each side of which one of the elements 37 is arranged. It will also be seen in Figure 4 that the parts 37 are disposed so that their cutting portions 41 are disposed diagonally across the group in a manner similar to that referred to above in connection with the punch parts 19. Spacing members 43 are also interposed between the lower punches 36 and 37.

Still further, and similarly to the manner.

described above in connection with the upper punch parts, the two transverse series of lower punch groups are oppositely inclined in order to cooperate with the oppositely i11- clined upper punch groups. It will also be understood that the arrangement of the elements 87 in the oppositely inclined groups will bereversed or inverted.

Before considering the operation of these various punch parts, reference should be.

made to Figures 1, 2 and 3 in which I have illustrated a novel type of stripper mechanism applied to the punching elements in order to strip the metal therefrom after each press actuation. This stripper mechanism includes a pair of plates 44 and 45 which are secured to each other at each side of the path of movement of blanks through the apparatus, as by means of bolts 46 clearly illustrated in Figure 1. plates are spaced from each other by means of the strips or parts 47 (see Fig. 2), these In addition, the two stripper o parts 4'? a so being disposed laterally of the As clearly seen'in Figure 1, each of the A stripper plates 44 and 45 is provided with a plurality of elongated apertures 52 of such dimensions as to permit the projection therethrough of any one of the punch elements 18, 19, 36 and 37.

or ligaments 53 are disposedin such manner as to fall between the adjacent punches of each group. The stripping action, therefore, is very thorough and complete, this being an important factor in a multiple slitting apparatus' of the type herein disclosed for various reasons which are brought out more fully toward the beginning of this specification.

In considering the step by step slitting of a blank by the apparatus herein disclosed, attention is first called'to the fact that I pre- In this way, stripper fingers its cordance with my copending application above identified, are greater than the width of the strands ultimately to be produced in the blank sheets. Specifically, according to this invention, I employ slitting punches which are twice the width of the strands produced. That is, each cutting portion of each punch has a pair of parallel slitting edges, at its working face, which are spaced from each other a distance substantially equal to twice or double the width of the strands of the meshwork being produced. The strands, therefore, are produced by a double slitting operation, this being accomplished by arranging the punch inclination (with respect to the direction of feed), and the length of the feed step, in such manner that, at one operation, the groups of punches produce ts in the blanks which interleave with or i between slits produced during a precedpunch operation.

Vhile I have specifically disclosed a punch ment in which the punch elements themseliare double the width of the ultimate strands to be produced, it is to be understood that this invention in its broad aspect also contemplates utilizing such multiple width punches of more than twice the width of the st 2. ls to be produced. lVith such modified constructions, however, it will, of course, be necessary to alter the length of the feed step and/or to change the angular ity of the punches with respect to the direc tion of feed so that instead of double or simpleslitting, during successive press actri pie, quadruple, or even more finely 'nued slitting will result.

In order to clarify he manner in which the upper and lower cooperating slitting punches actually cut the slits in the blanks, I have, in Figure l, superinu'iosed the righthand groups of punches of Figure la on the right-hand group of lower elements of this Figure This view clearly brings out which edges of the various double width cutters are cit -tive in the formation of the slits.

In turther explanation of the manner in which the slits are produced, attention is ow called to Figure 9. This figure illus trates the arrznigement oi slits which would appear in a blank X which has been fed through the apparatus and subjected to a plurality of punching operations. In this particular instance, the rear edge of the blank is shown at the bottom of Figure 9 at Y, the direction of movement through the press mechanism being again illustrated by the arrow 17. The blank of Figure 9, therefore, may be considered as having been removed from the press mechanism just shortlv prior to the completion of the slits therein. For purposes of this description or explana tion I have applied a number of brackets to various groups of slits appearing in. Figure the various brackets, are numbered in re-"' verse order with respect to the time at which they are produced by the various punch cutters.

Reference is first made to the series 1,

etc, by which it will be seen that in the slitting operation defined by the bracket 1, a plurality of slits '81 are produced. The second bracket is applied to designate the group of slits .92. In a similar manner, the brackets 3, and 5 embrace groups of slits 53, 8-1 and s5.

The bracketii'ig of the reversely inclined slits, of course, is arranged in a similar manner. In this instance, however, the slits belonging to group 1a are designated at .21,

while slits within the group 2a are indicated at The various groups of slits in the two reversely inclined series, of course, are produced, respectively, by means of the revcrscr ly inclined groups of slitting punches. In addition to'this, considering one series of slits, it should be noted that the same slitting punches operate on the blank, in the succes sive press'actuations, to produce at each op- '3 oration one group of slits such as those indicated at 85, 84;, 83, etc. The feed step, furthermore, is so arranged that upon the immediately succeeding press actuation a portion of the slits produced overlap or interleave with the first set. Thus the strips of metal which lie between the slits produced in any one given operation are subsequently divided r It;

or split cent-rally by the slits produced in the N next following operation.

More specifically, the feed length, this being indicated in Figure 9 by the dimension arrows A, is equal to one-halt of the overall extension of any group of slitting punches (lengthwise ot the feed) plus a distance equal to the strand intercoimecting bridges located between the adjacent ends of any two aligned slits.

With the particular arrangement herein disclosed, i. e., with three slitting punch portions arranged in each group generally lengthwise of the feed through the appa ratus (so that a similar number of longitudinally aligned but spaced slits are produced, lengthwise of the feed), the feed step above specified results in the extension of slits produced by any two successive punch actuations, generally speaking, substantially overlapping .or interleaving to a point adjacent the mid-points of the two groups.

leave with those produced in the first opera tien, and still further slits which are e:;-

tended beyond the area first slitted andlie I entirely within an open or unslitted area of the blank. To carry the operation a step "further, the slitsproduccd at a. third press actuation results in the disposition of certain slits entirely between those last mentioned in considering the second operation.

This third operation also produces some slits which interleave only partially with said last mentioned grou) (making reference to the second teed step), and finally, this third actuation, in ila'e manner to the second, produces still further slits which are disposed entirely beyond the overall dimensions of the complete second group.

It reference be mate to Figure 9 which, as noted above, illustrates the condition of a hlanlc just shortly before the slitting thereof has been completed, it Will be seen that upon the next teed step (advancement of the blank the cistance defined by the dimension arrows A), the' punches which produced the slits (oinbrz ced in the bracket i) will be positioned substantially one-halt Within this b 'aclqet-ed are; and substantially one-halt thcreheyond in a direction, of course, op-

posite to that indicated by the teed arrow 17. This will result in inter-slitting between the Widely spaced slits s1 appearing at the bottom ot- Figure 9.

The manner in which the reversely incl'ned slits are produced is, of course, 'dentially from eac There is however one rather 'ini ortant v I n r "actor to consider in this connection. lhis relat to the mounting of the various puncl groups in th press inenihers. {)bviously, if tl e tron and rear transverse sets of punches are ar anged very close to each other, mount- -ng diiliculties will arise. On the other hand, it the two series are excessively separator, the i ppa at-us is needlessly enlarged and, in addition, inaccurate or irregular ieed might lt during movement of the blanks bei such wry widely spaced transverse It is an important feature of this invention, however. as clear V the puncheswhiclr are rever elv inclined aroarrangeu in series which are spaced substan- 21 other thus avoiding serious complications i h have fiQGll eiwountered toitore where punches inclined in both diions have been mounted in a single series extended transversely of the feed. The spaclug ofthe we trans\'er:-re series of punches is i.- dicated in Figure 9 by the dimension arrows B; An additional adr tage of applica-ints arrangement should also he nvted at this point. Referring again to the type of a; 1 'atus in v' i. h punches inclIneilinholh ll ctions are l d in a single transverse noted that even where this has been iouml to to pc sible, the resultant slitand strand tornnition ha. not been el .tici'vnt from the starulpoiut of the total i I n i' l lized in producing z.

1' :9 y given dimensions/ 7 (.y, where oppositely inii'llllCC are nioui'ited side by side feed through the app: ra-

. 1- 1 r; .nsverse use, more l r ticel with that just described, although it c 1 t-andp .=int she dd be noted th. t, in View of the mounti 1 t 3 1 'ength and 5.1m or the reversely inclined punches beyond, w ill? Thug il/iclllllllll i l respect to the directionof feed, the es first considered, such oppositely anoessive gerations have been performed by the first mentioned punches; .ehe point at l the second groups or" punches begin to ate need not be positioned at any particular point with respect to the ope ation the forward cutters, although, as indil in Figure 9, it is desirable that the slits 'e inclined in each directi should red in; transverse rows or series ut the entire Width of the blank. In their Words, the punches should he range in such manner that theslits e1,

c, terminate t their ends along th same transverse lin which the s. terminate.v This arrangement, as Will reanily be understood, may be modified to bring the lowermost slits 21 into transverse altruinent with substantially any'of the slits s2, s3, s4, 35, etc.

dam

cants invent on, ihe

punches in one direction in one t I .'i a similar 5 position of the oppositely unclie SOl'iGS spaced feed; the op V sion of Hi w er, it sh naratus of this ned to includ lie ap inodh are groely incline tuzen nth This, it w ll he app 1 result in sligh y more complicated mount- 1+ inteiieiinn rrangenien s and possioly sonin enceoi the puncl groups in either or ooth of 3 y pointed out above, that W I where multiple slitt-i" the transverse series but, as noted, will sti l result in the attainment of advantages herein contemplatedat least as to the mounting of certain groups of punches. The foregoing is noted to bring out the fact that while I pretcr to incline all of the punches in each transverse series in the same dir :tion, I. may also attain objects of this invention l a. some what modified arrangement. Still other slight modifications may also b 1 made without departing from the general spirit or broad aspect of the invention.

Turning again to the punches ot each group, it should also be borne in mind that the essence of the multiple punch arrangement herein disclosed may c incorporated in punch elements which include more .or less than three slitting cutters arranged in a 21- ment generally lengthwise ot the feed. (lbviously, the number may be incre :d to within any reasonable or practica limit and, with each increase in the nu. her, the detailed arrangement of the punches themselves will be slightly modilie'd and the length of feel; oi the blanks through the apparatus correspond ingly altered.

From the foregoing it will be apparent that high speed production or 1 ieration is a.rainable by the use of apparatus such as that pre sented as an example herein. i the same time, the structure readily lends ll? to the use of the desirably duraole double or multiple width slitting punch feature referred to in more detail hereabove. 7

\Vhile I prefer to make the in" punch pieces or elements substanth. 1 form illustrated in Figures 5 to S inclusive, at the same time, a plurality of individual parts may be employed tor this purpose. The,

preferred .rrangeinent, however, all'ords numerous advantages which are of substantial importance as will readily be understood when it is considered that practically the entire maintenance and upkeep of a-machine of this character involved in replacement and/or regrinding the cutters. The various punch parts lend themselves very rca .ily to tapering or rounding of their cu g edges to provide for a shcarin action during actual slitting, this being of very great im 't-ance is being ca ed out. The term multiple slit g as here employed, of course, is used to designate the general type of slittin which involves the formation of a plurality of slit-s in. lines or Zones than parts such as 18 and 19, be machined togetl er in groups, at least as to certain of their surfaces or edges.

Still another advantage of the particular type of slitting punches herein disclosed lies in the fact that only one base portion is employed to support or lend backing to a plurality of more or less independent slitters. [his results in accurate alignment of the slitting punches as to their height and, additionally, materially simplifies the mounting and securing arrangements which must he made. In this connection it should be borne in mind that an undue multiplicity of independent or individual parts aggravates the problem or adequate and rigid support. The present invention, therefore, provides a mar-:innnn of rigidity and general strength not only inherently in the punches themselves but also in the punches in their individually mounted units or groups.

In considering the mounting and securing dilliculties which have been encountered heretofore, and also the manner in which they have been overcome by the structure of the present invention, it should be noted that, in the production of lathing having inclined strands and slits, it is desirable that each row or series of transversely of the blanks, and ot' the direction of feed through the apparatus, should include strands or slits some or which are inclined in one direction and some of which are inclined in the opposite direction. The fundamental reason for this lies in the fact that if all the slits are inclined in one direction, during expansion of the blanks, bending of the strands with respect to their interconnecting bonds or bridges would result in the production of very irregularly shaped sheets and, in addition, would not provide proper strength and rigidity as against bending or flexing particularly on certain diagonal lines. I r

In order to produce blanks having the desirable oppositely inclined arrangement of slits, in zones or strips extended transversely of the blanks, it is necessary, of course, to dis pose slitting punches in groups which are similarly oppositely inclined. In prior constructions such groups of punches have all been mounted within a single elongated Zone or area extended transversely of the feed of the blanks through the apparatus. This resulted in considerable complication in suitably mounting and securing the punches in the press members for the reason that, in order to make the best possible or most ethcient use of the material being slit, the punches must be disposed closely adjacent to each other within such zone or area so that the slits likewise fall in close proximity to each other. Even where relatively wide unslitted strips or zones were provided in the blanks lengthwise thereof (these Zones or strips usually being bent upinto strengthen- Cal 'Lal

all:

ing ribs) it has been difficult to mount the punches sufficiently closely to each "other to eihciently make use of the m-aterialof the blanks, for the reason that a multiplicity of slits must still be provided between theadjacent unslitted strips. On the other hand, if the number of unslitted strips is increased to further simplify the mounting, this, of course, also resulted in inefiicient utilization of the material of the blanks.

In addition to the foregoing, it should be noted that the efficient use of the material and proper mounting of the slitting punches is still more difficult and complicated where a plurality of punches are arranged in the press mechanism generally lengthwise of the feed therethrough as well as transversely of such feed.

With a view to overcoming difficulties of the character above noted, this invention pro vides for the disposition of the multiple width punch elements above referred to, in two or more zones or areas extended transversely of the feed and preferably spaced from each other lengthwise thereof. Each one of these zones or areas, in accordance Wlbll this invention, includes a plurality of slitting punches or slitting punch portions arranged to produce a multiplicity of slits in strips extended lengthwise of the feed as well as transversely thereof. All of the punches of one zone are further inclined inone direction with respect to the feed through the apparatus, while all of the punches of the other zone are oppositely inclined, 1 the punches in each zone being arranged in groups which are spaced from each other transversely of the direction of feed. With such an arrangement, and with the groups of punches in one zone stagger-ed with respect to the groups in the other zone, it will at once be apparent thatrthe construction in general is such as to provide for the production of slits disposed or set closely adjacent to each other transversely of the blanks. This, furthermore, is obtained, in accordance with this invention, without undue complication arising from the mounting of the punchesin the press members in view of the greater spacing of the groups of punches.

The mounting is further simplified by virtue of the fact that all of the punches of one group are inclined in one direction, it being noted that where punches inclined in'both directions are mounted within a single transverse zone or area, the opposite inclination necessarily brings the punch parts themselves as well as their mounting and securing elements closely adjacent to each other in the direction or in the region of split convergence. I

In addition to all the foregoing the use of double width punches in a multiple slitting machine provides the following advantage: In such multiple slitting machines there are,

of course, a great many punch parts engaging the blanks at eachoperation. Indeed, this engagement is progressively and correspondingly increased as the number of punches is multiplied. In multiple slitting apparatus heretofore employed this extended or increase engagement has resulted in certain stripping difficulties, hereinb'efore re ferred to, for the reason that it, has not been possible heretofore, at least as a practical matter, to inter-pose stripping fingers or ligaments in between adjacent punches of any of the groups. This, of course, resulted in relatively large blank areas, defined by the external dimensions of the groups of punches which were left entirely without stripping action. However,- according to the multiple Y arrangement herein disclosed, the use of double width interleaving cutters results in the spacing of the cutters a distance which is sufficient to accommodate stripper ligaments. As will be readily understood, this stripping difficulty has presented itself in its most aggravated form heretofore in multiple slitting machines which were designed to produce some of the more narrow strand-ed fabrics, these narrow stranded fabrics being more and more widely employed in accordance with modern building practice. While the stripping advantage of applicants apparatus is most advantageous where relatively narrow stranded fabric is being produced, at the same time, the principle of the use of double width punches, in multiple arrangement, with ligaments between adjacent punches, is also advantageous even in producing some of'the more widely stranded ma terials.

A further advai'itage, over multiple slitting apparatus heretofore employed, is involved in the matter of feed of the blanks. Generally stated, this advantage liesin the fact that a feed inaccuracy of a given percentage will result in a smaller ultimate irregularity in the strands produced than the same percentage of inaccuracy in former machines. This is explained by thefact that the use of double Width punches in multiple arrangements results in somewhat extended fee-d steps which provide for the inter-leaving of slits produced during successive press actuations. A

given percentage of inaccuracy, therefore, distributes the irregularity over a greater number of ultimate strands and with'this distribution the irregularity as to each strand, of course, is very small indeed. In further explanation of this matter, attention is called to the fact that heretofore where multiple slitting has been adopted, the slits produced at successive press operations did not interleave but were disposed successively entirely beyond previously formed slits. With such an arrangement, where an inaccuracy occurred,ithe result was an irregular formation of strands (that is, the formation of abnormally narrow or wide strands) in a single series thereof extended transversely of the feed through the apparatus.

In comparing my improved multiple shtting apparatus with others heretofore employed, it should be pointed out that the double width punches arranged in multiple formation, especially when the elements themselves are configured in the manner above described, greatly facilitate the formation of shearing cutting edges. This is due to the fact that the punch portions of each punch element are separated and spaced from each other so that the necessary grinding or finishing may readily be accomplished and, indeed, may be performed on the punches in groups. That is, such shearing edges may be cut or ground on a plurality of punch ele ments at one operation.

The present invention, therefore, provides for the production of much more uniform meshwork than has been possible heretofore,

. particularly in accordance with the multiple 4 slitting punches mounted in the press members and arranged to interleave upon actuation thereof, the slitting punches of each group having their cutting edges inclined with respect to the direction of feed through the apparatus, and there being groups of slitting punches having their punches inclined in opposite directions with respect to the direction of said feed, with the groups inclined in one direction disposed beyond (with respect to the direction of feed) the groups inclined in the other direction.

2. In combination with cooperating press members adapted to the intermittent feed of blanks therethrough, groups of cooperating slitting punches mounted in the press mem bers and arranged to interleave upon actuation thereof, the slitting punches of each group having their cutting edges inclined with respect to the direction of feed through the apparatus, and there being groups of slitting punches having their punches inclined in opposite directions with respect to the direction of said feed, with the groups inclined in one direction disposed beyond (with respect to the direction of feed) the groups inclined in the other direction, together with a device operative as to a plurality of groups of punches for securing them in position.

3. A punch part of generally flattened shape for use in a sheet metal slitting press, the punch part including a plurality of slitting portions also of flattened shape disposed in the general plane of said part and spaced from each other.

4. A punch part of generally flattened shape for use in a sheet metal slitting press, the punch part including a plurality of slitting portions also of flatten'edshape disposed in the general plane of said part and spaced from each other, each of said portions having a pair of substantially parallel slitting edges.

5.'A punch part of generally flattened sha pc for use in a sheet metal slitting press, the punch part havinga working edge portion with a slitting edge at each side thereof, the slitting edges being interrupted or cut away intermediate the ends thereof, and there being an interruption in each slitting edge disposed adjacent to each other at opposite sides of the punch part.

6. A punch part of generally flattened shape for use in a sheet metal slitting press, the punch part having a working edge portion with a slitting edge at each side thereof, the edge portion being cut away or recessed intermediate its ends to provide interruptions in said slitting edges opposite to each other transversely of the punch part.

7. In apparatus of the character described, a pair of groups of slitting parts, each group including slitters spaced from each other, a punch holder member having an aperture therein adapted to receive said pair of groups of slitting parts in spaced relation, and wedge means interposed between the groups of the pair for securing all the slitters of the two groups in their operative positions.

8. In a slitting press mechanism adapted to the intermittent feed of sheets therethrough, a press member having a plurality of spaced groups of slitters mounted therein, the groups being arranged in at least two series extended transversely of the direction of feed and spaced from each other lengthwise of the direction of feed. Y

9. In a slitting press mechanism adapted to the intermittentfeed of sheets therethrough, a press member having a plurality of spaced groups of slitters mounted therein, the groups being arranged in at least two substantially independently mountedseries extended transversely of the direction of feed,'with the slitters of the groups in one series all inclined in one direction with respect to the direction of feed and with the slitters of the groups in another series all inclined in the opposite direction with respect to .the direction of feed.

10..In a slitting press mechanism adapted to the intermittent feed of. sheets therethrough, a press member having a plurality of spaced groups of slitters mounted therein,

the groups being arranged in series extended transversely of the direction of feed, with the slitt rs of the groups in one'series all inclined in one direction with respect to the direction of feed and with the s'litters of the groups in another series all inclined in the opposite direction with respect to the direction of feed, the groups of the series further being odset with respect to each other longitudinally of the direction of feed and staggered with respect to each other transversely of the direction of feed.

11. In apparatus of the character described, a press mechanism, a plurality of groups of slitting punches mounted in the press mecha nism, each one of said groups including a plurality of punches spaced from each other generally lengthwise of t ie direction of feed and a plurality of punches spaced from each other transversely of said feed to receive similar punchelements therebetween, and all of the punches of each of said groups further being inclined with respect to the direction of feed through the apparatus.

12. In apparatus of the character described, a press mechan sm, a plurality of groups of slitting punches mounted in the press mechanism, each one of said groups including at least the following elements all mounted in close association with each other, a plurality of punches spaced from each other generally lengthwise of the directionoi feed and a plurality of punches spaced from each other transversely of said feed and all of the a punches of each of said groups further being inclined with respect to thedirection of feed through the apparatus; together with means for securing the punches of each group in operative position as a unit.

13. In apparatus of the character described, a press mechanism, a plurality of groups of slitting punches mounted in the press mechanism, each one of said groups including at least the following elements all mountedin close association with each other: a plurality of punches spaced fromeach other generally lengthwise of the direction of feed and a plurality of punches spaced from each other transversely of said feed, and all of the bunches of each of said groups further being inclinedwith respect to the direction of feed through the apparatus; together with a stripper mechanism having ligaments positioned for effective stripping action within at least some of the spaces between adjacent punches in each group.

14. In apparatus of the character described, a press mechanism, a plurality of groups of slitting punches mountedin the I press mechanism, each one of said groups in cluding a plurality of punches spaced from each other generally lengthwise f the direction of feed and a plurality of punches spaced from each other transversely of said feed, and all of the punches of each of said groups further being inclined with respect to the direction of feed through the apparatus, there being groups of oppositely i clined punches spaced from each other generally lengthwise of the direction of feed through the apparatus.

15. In apparatus of the character de scribed, 21. press mechanism, a plurality of groups of slitting punches mounted in the press mechanism, each one of said groups including a plurality of punches spaced from each othergenerally lengthwise ot' the direction of feed and a plurality of punches spaced from each other UQDSVGTSGlY of said feed, and all of the bunches of each ot-said groups further being inclined with respect to the direction of feed through the apparatus, there being groups of oppositely inclined punches spacedand offset from each other generally lengthwise of the direction of feed through the apparatus.

16. In apparatus or" the character described, a press mechanism, a plurality of groups of slitting punches mounted in the press mechanism, each one of said groups including a plurality of punches spaced from each other generally lengthwise of the direction of feed and a plurality of punches spaced from each other transversely of said feed, and all of the punches of each of said groups further being inclined with respect to the direction of feed through the apparatus, there being groups of inclined punches spaced and offset from each other generally length wise of the direction of feed through the apparatus. 7

17. In combination with cooperating press members for slitting metal blanks, cooperating slit-tin punches mounted in the members, and a stripper mechanism for the slitting punches including a pair of stripper parts secured to each other in spaced relaticn-to provide for the feed of blanks therebetwecn.

18. In combination with cooperating press members for slitting metal blanks, cooperating slitting punches mounted in. the members, and a stripper mechanism for the slitting punches including a pair of stripper parts secured to each other in spaced relation to provide for the feed of blanks therebetween, said mechanism being resiliently mounted on one of the press members.

19. In combination with cooperating press members for slitting metal blanks, cooperating slitting punches mounted in the members, and a stripper mechanism for the slitting punches including a pair of stripper parts fixedly mounted with respect to each other in spaced relation to provide for the feed of blanks therebetween.

20. In combination with cooperating press members for slitting metal blanks, cooperating slitting punches mounted in the members, and stripper mechanism for the slitting punches including a pair of stripper parts fixedly mounted with respect to each other in spaced relation to provide for the feed of blanks therebetween, together with spring means for resiliently mounting said mecha nism on one of the press members.

21. Apparatus for slitting metallic blanks for expansion into meshwork laving strands of predetermined width, including reciprocating slitting mechanism adapted to the intermittent or step by step feed of blanks therethrough, slitting elements having cutting edges spaced apart in parallel alignment :1 distance g'e'atcr than the predetermined width of a strand, said cutting edges being incline with respect to the direction of feed through the apparatus, there being slitting elements arranged generally longitudinally in groups of length considerably greater than the length of a feed step, whereby slits formed in a blank by a portion of a group of slitting elements in one operation lie between and in parallel alignment with respect to the cutting edges of other slitting elements in said group, so that, by continued actuations of said slitting mechanism, strands of said predetermined width are produced.

22. In apparatus for slitting metallic blanks for expansion into meshwork having strands of a predetermined width, cooperating press members adapted to the intermittent feed of blanks therethrough, slitting punches mounted in the press members hav ing parallel cutting edges laterally spaced apart a distance greater than the predetermined width of a strand, and further having cutting edges arranged in longitudinal alignment but inclined with respect to the direction of the feed through the apparatus.

23. In apparatus for slitting metallic blanks for expansion into meshwork having strands of a predetermined width, cooperating press members adapted to the intermittent feed of blanks therethrough, groups of slitting punches mounted in the press members having parallel cutting edges laterally spaced apart a distance greater than the predetermined width of a strand, and further having cutting edges arranged in longitudinal alignment but inclined with respect to the direction of feed through the apparatus, the

working faces of slitting punches in a group being configured to provide shearing action to the cutting edges upon interleaving thereof with slitting punches of a cooperating group.

24:. In apparatus of the character described, an apertured punch holder member, groups of slittin punches mounted in an aperture of said holder member, and a wedging device operative between said groups of slitting punches including a cooperative pair of parts, one having lateral movement and the other longitudinal movement with respeet thereto, together with means for tightening said device to securely hold the slitting punches in position.

25. An article of manufacture, a slitting punch for producing meshwork strands of a predetermined width having parallel cutting edges spaced apart a distance greater than the predetermined width of a strand, and having a series of cutting edges arranged in longitudinal alignment, with the working faces of the punch configured to provide a shearing action to said cutting edges.

26. Apparatus of the character described including press members, cooperating sets of slitting punches mounted in the press members and arranged to interleave upon actuation thereof, and stripper plates apertured to pass the punches of a set to provide for engagement with the punches of a cooperating set, the stripper plates for. the cooperating sets of slitting punches being securely fastened together but spaced apart to allow the feeding of blanks therebetween, and said plates further being resiliently mounted, together with means for limiting movement of said plates.

27. In a slitting punch stripping device, stripper plates having apertures therein to allow the passage of the slitting punches of a set to engage the punches of a cooperating set, said stripper plates being securely fastened together in spaced relation, together with means for guiding the blanks between said plates.

In testimony whereof I have hereunto signed my name.

HERBERT K. BAKER.

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