US3786732A

US3786732A - Cutting and scoring die

Info

Publication number: US3786732A
Application number: US00226727A
Authority: US
Inventors: H Forbes
Original assignee: Westvaco Corp
Current assignee: Westvaco Corp
Priority date: 1972-02-16
Filing date: 1972-02-16
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22

Abstract

An apparatus for cutting and scoring sheet-like material is described comprising a single die plate which includes both severing elements and scoring elements mounted thereon. The severing elements constitute the usual knife blades employed in prior art sheet cutting and scoring dies. However, the scoring elements constitute novel pairs of knife blades which eliminate the need for a conventional makeready or female die as required in the prior art devices.

Description

United States Patent .[191

Forbes, Jr.

[ Jan. 22, 1974 CUTTING AND SCORING DIE [75] Inventor: Hampton E. Forbes, Jr.,

Wilmington, Del.

[73] Assignee: Westvaco Corporation, New York,

[22 Filed: Feb. 16, 1972 211 Appl. No.: 226,727

[52] US. Cl 93/583, 83/9, 83/11 [51] Int. Cl B265 1/44 [58] Field of Search 83/9, 11, 12, 6, 7, 684; 93/5858.3

[56] References Cited UNITED STATES PATENTS 1,592,094 7/1926 Funk 93/582 R 695,029 3/1902 Blevney... 2,586,744 2/1952 Troth..

2/1971 Wo1fe...., 93/582 R 3,481,813 12/1969 Wiggers 93/582 R 1,288,132 12/1918 Nagle 83/7 FOREIGN PATENTS OR APPLICATIONS 9,097 0/1887 Great Britain 83/1 1 Primary Examiner-J. M. Meister Attorney, Agent, or Firm-Larry C. Hall et al.

[57] ABSTRACT An apparatus for cutting and scoring sheet-like material is described comprising a single die plate which includes both severing elements and scoring elements mounted thereon. The severing elements constitute the usual knife blades employed in prior art sheet cutting and scoring dies. However, the scoring elements constitute novel pairs of knife blades which eliminate the need for a conventional makeready or female die as required in the prior art devices.

7 Claims, 11 Drawing Figures FIG.

PATENTEBJAI 22 m4 SHEET 1 0F 2 CUTTING AND SCORING DIE SUMMARY OF INVENTION The present-invention relates to apparatus for cutting and scoring sheet-like material and particularly relates to a novel die structure for cutting and scoring sheetlike material. The die structure comprises a single die plate having both the severing and scoring elements mounted thereon to effect both the severing and scoring of sheet-material positioned between the die and a smooth backing surface.

The customary method of cutting and scoring paperboard or the like requires the use of both a male die and a female die, or makeready, to cooperate with the male die. With these conventional elements, a blank of paperboard or other material is cut and scored by passing the blank between the male die and the makeready which are mounted in a piece of die cutting machinery. In setting up a conventional blank fed cylinder machine to manufacture a particular form of paperboard blank, a large piece of hard, solid manila board called a counter sheet is initially pasted to the surface of a metal jacket which is then bolted to the periphery of the machine cylinder. Themetal jacket serves as a removable surface for the cylinder and as a carrier for the counter sheet adhered thereto. Next, portions of the counter sheet are cut away to form channels which serve as the female, or makeready die for creasing the carton blank. In an effort to insure that the cutting of the counter sheet is done accurately, it has been customary to mark guidelines for the cutting operation on the surface of the counter sheet. This step is accomplished by operating the machine with a piece of carbon paper or the like between the surface of the counter sheet on the cylinder and the normal male scoring die. In this manner, an impression of the die is made on the surface of v the counter sheet as a guide for aiding the cutting away of the counter sheet to form the female die or makeready. The creasing, or fold line portions of the male die make a heavy line on the counter sheet and the cutting portions of the male die generally make thin lines on the counter sheet by actually cutting through the carbon paper when the facsimile is being made. After the guidelines for the particular blank are made on the counter sheet, highly skilled workmen then use hand tools to cut away portions of the counter sheet along the heavy lines to form the female creasing channels of the makeready, and, also cut away the counter sheet entirely to expose the sealed surface of the metal jacket where the fine lines have been made by the cutting die. Obviously the usual operation of preparing the creasing counter, or, makeready is a laborous, detailed and time consuming one in which the workmen must perform a very exacting procedure. By recognizing these and other deficiencies in the preparation of the scoring dies described by the prior art, the apparatus of the present invention was developed in an effort to eliminate the need for any skilled layout or makeready work by substituting a simple, single die element to perform both the cutting and creasing operations without need for a makeready.

Accordingly, the present invention relates to the air of forming score lines and cut lines in carton blank material. More particularly the invention concerns an apparatus which eliminates the need for a makeready or female die, against which the male die part presses, to

form the score lines and cut lines in carton blank material.

It has been found to be of great importance to provide well formed scores in carton blanks so that panels of the blanks may be assembled to form cartons which are uniform in dimension and attractive in appearance. Inadequate or defective score lines in a carton blank prevent such folding because the carton material tends to resist the folding that takes place in an assembling operation. In many instances, inadequate scores cause the jamming of automatic carton forming machinery. For example, if the scoring is not precisely the same in all the cartons of a large number which pass through a carton forming machine, the flaps of the carton blank that are to be glued together will not be properly positioned with respect to one another, and with respect to all the carton blanks which pass through the machine. Such improper positioning of the flaps results in flaps not being properly applied'with adhesive, or flaps which extend beyond the glue portion of a cooperating flap causing premature separation from that flap. In addition to the structural and functional defects in cartons which have improperly formed score lines, the effect of such inadequate scores also tends to cause cracking on the outside of the score. That is, the unsightly and weakened cracks occur in the outermost ply of the paperboard used to form the carton, or in a paper ply laminated to the board from which the carton is made. Where a paper ply is employed which has sufficient strength that it will not crack or break, even though improperly scored, the cost of such ply makes its use highly undesirable. Still another disadvantage of improper scoring is that it results in knocked-down carton blanks which do not stack or feed properly into automatic carton machinery because some of the scores have been squeezed down while others still remain properly oriented causing the stack of carton blanks to either lean to one side or teter back and forth.

It has been determined by the prior art equipment that a properly formed score is one in which the outer surface or printability side of the carton material has been so depressed that a bead is formed on the inner surface of the materiaLThis bead in a proper score or crease is substantially symetrical. Thus, in accordance with the prior art devices, proper scoring is aided by employment of correctly positioned, precisely aligned creasing rules or male die parts having smooth, well formed creasing surfaces. In addition, the female die part generally used must include elongated regions into which the creasing rules of the male die press part of the blank material to form the aforementioned beads. These elongated regions, of course, must have been formed with side walls which are highly resistant to wear. However, with the novel scoring and cutting die of the present invention, the scores and cuts are made on the inside of the carton blank rather than on the outside or printability side as with the prior art equipment. For the novel die disclosed herein, the outer surface of the carton material is not depressed and no bead is formed therein by the scored lines. In summary, the principle object of the present invention is in the provision of a new and improved cutting and scoring die which eliminates the need for the makeready part used in the prior art die cutting processes. The die element described herein is relatively low in cost, can easily be made with a great deal of accuracy, and operates with a minimum of material becoming lodged in the die.

A still further object of the present invention is the provision of a novel die element, for cutting and scoring sheet like material, which comprises a single die plate having both severing elements and scoring elements mounted therein, the severing elements on the die plate being in the form of single blades which project above the main surface of the die plate a distance sufficient to completely sever the sheet like material, and, the scoring elements of the die plate preferably comprising paired, cutting blades which project above the main surface of the die plate a distance sufficient to penetrate the blank material only slightly, and just enough to rupture the uppermost surface of the material, thereby forming scored lines.

DESCRIPTION OF DRAWING FIG. 1 is a plan view of a die plate in accordance with the present invention for cutting and scoring a single blank of material;

FIG. 2 shows a carton blank as cut and scored by the die plate of FIG. 1;

FIG. 3 is an enlarged perspective view of the die plate shown in FIG. 1;

FIG. 4 is a cross-sectional view of the die plate taken along the lines 44 of FIG. 3;

FIG. 5 is a partial cross-section of the die plate, similar to FIG. 4, but showing a modification of the FIG. 4 structure;

FIG. 6 shows schematically an example of a prior art scoring die and makeready;

FIG. 7 shows a typical score line prepared by the prior art devices;

FIG. 8 shows an exaggerated view of the score line of FIG. 7 with the scored material folded;

FIG. 9 shows schematically the arrangement of the die plate and smooth backing plate of the present invention;

FIG. 10 shows a typical score line as formed by the novel die of the present invention; and,

FIG. 11 shows an exaggerated view of the score line of FIG. 10 with the scored material folded.

DETAILED DESCRIPTION The present invention provides an improved cutting and creasing die of the type which includes both cutting rules and creasing rules mounted therein. The cutting rule portions of the die are in the form of blades which project above the main surface of the die plate and perform the normal blank cutting function. The scoring element portions of the die are also cutting blades and they are mounted on the die plate in order to effect the scoring of the sheet material at the desired locations. It is in the construction of the scoring element portions of the die that the novelty of the present invention lies.

The scoring elements of the present invention do not comprise the normal round edged rules as used in the prior art, which require a makeready or female die portion in order to effect the scoring operation. To the contrary, the scoring elements of the present invention are in the form of paired scoring knives which are separated from one another a distance which is only slightly greater than the thickness of the blank material being scored and cut. Accordingly, a typical carton blank is cut and scored in accordance with the present invention by simply positioning a blank of material between the novel die and a smooth, flat backing portion.

For the purpose of describing the present invention, only a single carton blank is shown in FIG. 2 of the drawing. However, it should be apparent that in normal manufacturing functions, a plurality of carton blanks are generally formed from a single sheet of material, by a single die, which includes a multiplicity of the scoring and cutting elements positioned thereon. Alternatively, the material from which the carton blanks are cut could be in the form of a roll of sheet material rather than the individual pieces of sheet material as particularly illustrated in the drawing.

The typical carton blank disclosed herein will not be described in detail since the specific details of the carton blank are not important to the present invention, and any design of carton blank could be cut by the die of the present invention without encountering any difficulty. It should suffice to state that the carton blank shown in the attached drawing includes a plurality of panels which comprise bottom, top and side panels to be formed from the blank. In addition flaps and tabs are positioned on the carton blank for the purpose of securing the various panels together to form a carton.

FIG. 1 illustrates an example of a male die 10 for cutting and scoring the carton blank shown in FIG. 2. The die includes a main body or die plate portion 11 with a series of cutting knives 13 extending outwardly therefrom. The cutting knives l3 serve to form the outside perimeter of the carton blank and also cut the blank in those areas which form the closure flaps 27, 28 and glue flap 29 for fabricating the carton. Accordingly, the severing knives 13 are positioned on the die plate 11 so as to cut the sheet material at the desired location in order to form the lines of severence in the sheet material. The novel scoring knives 12 are also located on the die plate 11 in position to score the carton blank at the desired locations-to form the score lines 12.

In the prior art processes, the scoring of a sheet of material was accomplished by locating the male scoring elements on a die so as to force the blank material into spaces cut from the female makeready as disclosed hereinbefore. In this manner, the scoring elements of the prior art devices tended to crimp the blank material and provide socre lines as shown in FIG. 7 of the drawing. However, in the case of the novel scoring knives disclosed in the present invention, the score lines are produced by forming parallel cut or weakened lines which extend into the sheet material only a short distance.

FIG. 3 of the drawing illustrates an enlarged view of the die plate of FIG. 1 showing the arrangement of the scoring knives in accordance with the present invention. Note that the scoring knives 12 are spaced apart from one another a distance which is equal to approximately 2.5 times the thickness of the sheet material from which the carton blank is cut. The exact spacing of the scoring knives 12 from one another is not a critical part of the present invention and could be readily determined by one skilled in the art. Generally, however, in accordance with the present invention, the space between a pair of parallel scoring knives is equal to a factor of from 2.2 to 2.8 times the thickness of the material to be scored. The spacing of the parallel scoring knives may be achieved by any well known means, but preferably, the use of spaCing blocks of known thickness is desired. In addition, FIG. 3 also shows the resilient elements 14 which tend to force the blank of material from the die after the impressions are made.

The elements 14 are particularly necessary in the region of the cutting knives 13 to prevent any jam-ups with the die cutting operation.

The view in FIG. 4 shows the relative relationship of the scoring knives 12 and cutting knives 13 with respect to the surface of the die plate block 11. Even though the relationships are drawn in an exaggerated manner, it should be readily apparent that the cutting knives 13 must extend further away from the surface of the die plate block 11 than the scoring knives 12. This relationship is required because while the cutting knives 13 must completely penetrate and sever the blank material, the scoring knives 12 need only kiss or slightly penetrate the blank material to form a weakened line therein. The view in Flg. 4 also shows. only one form that the scoring knives 12 may take in carrying out the present invention. As shown, each adjacent knife 12 is side face sharpened to obtain an oblique angular edge on each blade thereby insuring good penetration into the blank material while retaining high release characteristics. In addition, the angular edge of each adjacent scoring knife tends to compress the blank material remaining between the parallel lines formed by the scoring knives thereby preventing any undue interference with the folding capability of the material.

FIG. 5 illustrates another form that the scoring knives 12 might take. In this view, each adjacent knife 12 is center face sharpened to obtain a cutting edge formed by twin oblique angular cuts. For this embodiment, the release characteristics are improved, and the resistance to ultimate folding of the blank achieved is even less than with the side face sharpened knives. Obviously, the sort of blades chosen for the scoring knives would depend on the thickness of the blank material to be cut and the kind of carton being formed. In this regard, the present invention is intended to encompass the use of any desirable form of blades including blades having continuous cutting edges, or, blades with interrupted cutting edges as the scoring knives.

In the prior art apparatus, shown schematically in FIG. 6, the male die plate 30 has a scoring rule 32 mounted in a block 31. In this form, the male die cooperates with a makeready 33 secured to a counterplate 34 for scoring the blank material 40 positioned therebetween. Thus, all prior art cartons have been scored on the printability side to leave an indentation 30 for absorbing the compression of the blank material in the region of the fold line upon folding the blank. This arrangement is particularly illustrated in FIG. 7 of the drawing wherein a typical fold score line 36 is shown in cross section in a blank of material 40'. FIG. 8 shows the condition of the fractured material in the region of the score line 37 after the carton blank 40" has been folded.

In comparison with the arrangement just described, FIG. 9 shows a typical scoring installation embodying applicants invention. For this purpose, the male die plate 50 includes a pair of scoring knives 52 mounted in a block 51. The scoring knives illustrated at 52 are side face sharpened at an oblique angle as described hereinbefore. Using this configuration, the carton blank is scored in accordance with the present invention by placing the blank material 40 on the counter plate 53, and then moving the die plate 50 downward to bring the scoring knives 52 in contact with the blank of material as shown to produce the score line 55 illustrated in FIG. 10. FIG. shows the scored lines 55 as made on the inside of the carton blank 40' that is the side opposite the printability side of the blank. This scoring scheme is, therefore, opposed to the prior art teachings which always formed the score lines on the printability side of the carton thereby fracturing a portion of the carton which was immediately available and exposed to view. In accordance with the novel scoring technique described herein, any fractures in the blank material surface caused by the scoring knives disclosed are not exposed to view thereby leaving the exterior of the formed carton free of any interruptions in printing surface.

It should be apparent to one skilled in the art that the die plate constructed in accordance with the present invention could be made substantially flexible and bent in order to be mounted on a cylinder for effecting cutting and creasing of sheet material in the nip of a cylinder as shown in some of the prior art patents. Moreover, the die plate of the present invention could also be used in a flat bed or platen type cutting apparatus where reciprocating motion of at least one of the members of the press is effected by the apparatus. In addition, use of the novel scoring knives disclosed herein makes it easier to form curvedscores in sheet material. Furthermore, because thereis no makeready or female die portion necessary for the apparatus of the present invention, there is little tendency for the blank material to become stuck in the die. Thus, thefeeding of the material over the die can be readily accomplished on high speed machinery.

It is believed clear from the above description that applicant has provided a substantial improvement in the cutting and scoring art and that the die described herein has substantial advantages over the prior art systems. In summary these advantages involve the elimination of the problem of manufacturing the makeready or female portion of the die used in the prior art devices. As a result, the die of the present invention can be constructed at a substantially lower cost. In addition, the die constructed in accordance with the present invention has a minimum possibility of the material sticking thereto and thus there isless tendency for the die to create problems during the runnability of the carton blank. Moreover, the die of the present invention is generally of stronger construction and therefor has a 7 longer life with less damage than some of the prior art constructions.

Although only the preferred embodiment of the present invention has been completely described and disclosed hereinabove, it should be clear that certain modifications, constructions and adaptations could be made in the present invention and the disclosure herein is intended to cover all such constructions, modifications and adaptations which come within the scope of the appended claims.

I claim:

1. In an apparatus for simultaneously cutting and scoring the inside surface of sheet-like material in order to form blanks having uninterrupted exterior surfaces, a single die plate having both cutting and scoring elements fixedly mounted thereon, said cutting elements consisting of single sharpened cutting knives that extend beyond the surface of the die plate a distance sufficient to effect complete severance of the sheet like material and said scoring elements consisting of paired, parallel andv sharpened scoring knives, said paired scoring knives being separated from one another by a distance which is only slightly greater than the thickness of the sheet-like material being cut and scored and extending beyond the surface of the die plate a distance sufficient to produce score lines in said sheet-like material in the form of parallel cut lines which penetrate the sheet-like material sufficiently to rupture the uppermost surface thereof.

2. The apparatus of claim 1, wherein the paired, parallel and sharpened scoring knives which form the score lines each have a continuous cutting edge.

3. The apparatus of claim 1, wherein the paired, parallel and sharpened scoring knives which form the score lines each have an interrupted cutting edge.

4. A die for simultaneously cutting and scoring the inside surface of sheet-like material in order to form blanks having uninterrupted exterior surfaces, said die being adapted for mounting in a cutting and scoring apparatus and comprising a single die-plate, said die plate including both sheet severing elements and sheet scoring elements fixedly attached thereto, said sheet severing elements consisting of sharpened single cutting knives which extend beyond the surface of the die plate a distance sufficient to completly sever the sheet-like material and being positioned on said die plate where the sheet material is to be severed, and said sheet scoring elements consisting of paired, parallel and sharpened scoring knives said scoring knives in a pair being separated from one another a'distance which is only slightly greater than the thickness of the sheet-like material being cut and scored and extending beyond the surface of the die plate a distance sufficient to produce score lines in said sheet-like material in the form of parallel cut lines which penetrate the sheet-like material sufficiently to rupture the uppermost surface thereof and being positioned on said die plate where the sheet material is to be scored.

5. A die for cutting and scoring sheet-like material as defined in claim 4, wherein said sheet scoring knives are spaced from one another a distance of from 2.2 to 2.8 times the thickness of the sheet-like material being scored.

6. A die for cutting and scoring sheet-like material as defined in claim 5, wherein said single cutting knives and said parallel scoring knives are each center face sharpened to form their respective cutting edges.

7. A die for cutting and scoring sheet-like material as defined in claim 5, wherein said single cutting knives are center face sharpened and said parallel scoring knives are side face sharpened to form their respective cutting edges.

Claims

1. In an apparatus for simultaneously cutting and scoring the inside surface of sheet-like material in order to form blanks having uninterrupted exterior surfaces, a single die plate having both cutting and scoring elements fixedly mounted thereon, said cutting elements consisting of single sharpened cutting knives that extend beyond the surface of the die plate a distance sufficient to effect complete severance of the sheet like material and said scoring elements consisting of paired, parallel and sharpened scoring knives, said paired scoring knives being separated from one another by a distance which is only slightly greater than the thickness of the sheet-like material being cut and scored and extending beyond the surface of the die plate a distance sufficient to produce score lines in said sheet-like material in the form of parallel cut lines which penetrate the sheet-like material sufficiently to rupture the uppermost surface thereof.

4. A die for simultaneously cutting and scoring the inside surface of sheet-like material in order to form blanks having uninterrupted exterior surfaces, said die being adapted for mounting in a cutting and scoring apparatus and comprising a single die-plate, said die plate including both sheet severing elements and sheet scoring elements fixedly attached thereto, said sheet severing elements consisting of sharpened single cutting knives which extend beyond the surface of the die plate a distance sufficient to completly sever the sheet-like material and being positioned on said die plate where the sheet material is to be severed, and said sheet scoring elements consisting of paired, parallel and sharpened scoring knives said scoring knives in a pair being separated from one another a distance which is only slightly greater than the thickness of the sheet-like material being cut and scored and extending beyond the surface of the die plate a distance sufficient to produce score lines in said sheet-like material in the form of parallel cut lines which penetrate the sheet-like material sufficiently to rupture the uppermost surface thereof and being positioned on said die plate where the sheet material is to be scored.