US 3443489 A
Description (OCR text may contain errors)
M y 13,1969 ,mwATKms. 3,443,489
PAPERBOARD SCORING DEVIC E Filed June 1, 1967 I Sheet of 2 INVENTOR HARRY J WA TK/N$ A T TORNE Y5- May 13, 1969 i H. J.'WATKINS PAPERBOARD sconme pgzvmr:
Filed June 1, 19 67 I F/aj z INVENTOR HARRY J. WA T/(INS ATTORNEYS.
United States Patent 3,443,489 PAPERBOARD SCORING DEVICE Harry J. Watkins, West Berlin, N.J., assignor to The Langston Company, Camden, N.J., a corporation of New Jersey Filed June 1, 1967, Ser. No. 642,820 Int. Cl. 1331b 1/22 US. Cl. 93-581 Gaims ABSTRACT OF THE DISCLOSURE The scoring wheel of a double-faced corrugated paperboard scoring device has staggered relief areas on alternate sides of the scoring surface.
The present invention relates to an improved type scoring device to be used in the scorer-slotter station of a lprinter-slotter machine, of the well known type, which prints designs of one or more colors, scores and slots box blanks made of double-faced corrugated paperboard. When the score lines are applied to double-faced corrugated paperboard in a slitter-scorer machine of the well known type (this board being subsequently cut to length for the box blanks), the score lines are applied in a direction perpendicular to the direction in which the corrugated flutes run.
When score lines are applied in this direction in relation to the flutes, it is possible to score the board exactly parallel to the running board edges. However, when the box blanks are scored in the scorer-slotter station of a printer-slotter, they must be scored in the direction parallel to the direction in which the flutes run. When scoring is done parallel to the flutes, there is a strong tendency for the board to shift sideways so that the score lines are not applied straight but are skewed.
These skewed score lines, particularly for the fold lines for folding the outer panels 180 onto the inner panels, when the blanks pass through the folder-gluer machine, will result in the edges of the outer panels not being alinged with the edges of the inner panels and also will result in the gap at the manufacturers joint between the two outer edges of the outer panels, when folded 180 down onto the inner panels, being too small or too large at one or both ends of the folded box blank. This gap, at both ends, should be equal in width to the slots made in the box blank which permit folding the flaps to form the top and bottom of the box when it is erected and filled.
As a result of such misalignment and incorrect width of the gap, the box will not have the correct dimensions when erected and hence cannot be opened properly for filling without breaking the corners of the box. Such improperly formed boxes must then be discarded with the resulting economic loss. Furthermore, where the folded box blanks are opened by automatic machines, if they are not truly dimensionally correct, these machines will not function properly.
I surmise that the scoring surface, when moving parallel to and at the flute, which may start at any position on the crest or valley of the flute, acts like a snow plow pushing and building up material in front of it as it moves. The built-up material in front of the scoring surface causes the score line to skew in an attempt to equalize the material on each side of the score line. This problem is particularly detrimental on 180 fold lines which permit folding the outer panels down onto the inner panels of the box blank. These skewed score lines necessitate adding a squaring station in the folder-gluer which does not always do a satisfactory job of squaring.
I have solved this problem by radically changing the nature of the scoring surface on the scoring wheel. Thus,
3,443,489 Patented May 13, 1969 ice I provide the scoring surface with staggered relieved areas on alternate sides of the scoring surface. I hypothesize that the paperboard material is permitted to deform into the relieved areas thereby preventing the tendency of the material building up in front of the scoring surface. As a result, the present invention provides straight score lines parallel to the flutes which reduces the work to be done by or eliminate altogther the squaring station.
It is an object of the present invention to provide a device which will provide straight score lines in doublefaced corrugated paperboard parallel to the fiutes particularly the fold lines in a box blank which will permit automatically folding the outer panels of the box blank into edge-to-edge alignment with the edges of the inner panels and thereby provide folded box blanks which are dimensionally correct and which have the proper gap for the manufacturers joint.
It is another object of this invention to provide a method and device for scoring which will make sharply defined score lines which will be free from fractures of the inside liner and that will not cause the outside liner to fracture due to being stretched beyond its tensile strength.
It is another object of the present invention to provide a novel method of making a paperboard scoring device which is simple and economical.
Other objects will appear hereinafter.
For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangement and instrumentalities shown.
FIGURE 1 is a diagrammatic side elevation view of a slitter-scorer.
FIGURE 2 is a sectional view taken along line 2-2 in FIGURE 1.
FIGURE 3 is a sectional view taken along line 3-3 in FIGURE 2.
FIGURE 4 is an enlarged detail view of a score line made in accordance with the present invention.
FIGURE 5 is a perspective view of a box blank of the type particularly adapted for processing by the present invention.
FIGURE 6 is a perspective view of the blank in FIG- URE 5 but in a folded condition.
FIGURE 7 is an elevation view box blank.
FIGURES is an elevation view of an improperly folded box blank resulting from skewed score lines.
Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG- URE 1 a slitter-scorer designated generally as 10. The slitter-scorer '10 includes a frame 12 having scoring wheels 14 and 16 at spaced points along shafts 1-8 and 20 respectively. Slitting wheels 22 and 24 are similarly provided.
Referring to FIGURE 2, there is shown a set of scoring wheels 14 and 16. Wheel .14 is preferably a rubber or steel wheel having a finely knurled flat periphery 15. Wheel 14 is keyed to shaft 18 by key 24 and bolted to hub 26 by bolts 28. Wheel 14 may be adjusted along the length of shaft 18.
Scoring wheel 16 is similarly keyed to shaft 20 by key 30 and adjustable along the length of shaft 20. Wheel 16 is bolted to its hub 32 by bolts 34. Wheel 16 is preferably made of metal and has staggered relieved areas or recesses '36 on alternate sides of its scoring surface 38. As shown more clearly in the center of FIGURE 2, the adjacent land areas slightly overlap one another.
A typical operative embodiment of wheel 16 has a diameter of 6.22 inches, has the recesses 36 on one side repeated every twenty-four degrees for an arcuate length of .625 inch, and the depth of the recesses 36 was threeof a properly folded sixteenths of an inch. Thus, the length of each recess was ten percent of the diameter of wheel 16. These figures are illustrative and in no way limit the invention. The end faces 42 and 44 of the recesses 36 may lie along radii if desired.
Wheel 16 is preferably made in two halves, 39 and 40. The halves 39 and 40 are preferably disks which are simultaneously milled to provide the recesses 36 on their periphery. The halves are then rotated approximately twelve degrees with respect to each other so as to stagger the recesses 36 before drilling the holes for the bolts 28 and 34. Other processes for providing the recesses 36 will suggest themselves to those skilled in the art such as molding the halves 39 and 40* from suitable plastic material.
In FIGURE 5, there is illustrated a box blank 50 of double-faced paperboard particularly adapted for processing by the present invention. Blank 50 has longitudinal score lines 52 and 54 as well as transverse score lines 56, 60 and 61 parallel to the flutes. Slots 62 are provided in the box blank 50 by slotting wheels 22 and 2 4.
The box blank 50 may be folded by a folder-gluer to the disposition shown in FIGURES 6 and 7 and retained in that disposition by a glued flap or a tape strip 64. It will be noted that fold lines 56 and 60 are 180 fold lines since the panels on opposite sides thereof overlap one another. If the 180 fold lines are not perfectly straight, the blank 50 will not be properly folded as illustrated in FIGURE 8, and the ends of the score line will not bisect slots 62 and the gaps between the outer edges of the outer panels will be smaller or larger than the slots 62. Hence, fold lines 56 and 60 are desirably provided by the wheels 16 and 14 described above.
As shown in FIGURE 4, the relieved areas of wheel 16 produce a barely visible line 66 which zig-zags across the fold line 60. The areas 68, 70 and 72 on blank 50 are the areas which were opposite one of the recesses 36 on the scoring surface of wheel 16. These areas will later be on the inside of the box when it is erected for filling and the barely visible lines 66 will not be objectionable. Thus, it appears that the scoring Wheel 16 constantly and periodically at short intervals gets a fresh start as the scoring progresses by providing score line '60 as a series of short score lines which slightly overlap one another. The length of the short score lines corresponds generally to the arcuate length of the recesses 36. Those skilled in the art will recognize that the abovementioned wheels are axially adjustable along their shafts to accommodate box blanks of different widths and lengths.
The present invention may be used in machines other than a slitter-scorer. For example, the invention may be incorporated in a printer-slotter as per US. Patent 2,975,706, or substituted for the multiple scoring wheels shown in a folder-gluer as per US. Patent 3,282,175.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.
1. A paperboard scoring device comprising: a wheel having first and second peripheral surface portions, each of said portions having identical scoring surfaces, each of said surfaces having alternating land areas and relieved areas, the arcuate length of each of said land areas being approximately equal to the arcuate length of each of said relieved areas, each of said relieved areas on said first portion being opposite a corresponding land area on said second portion, and each of said land areas on said first portion being opposite a corresponding relieved area on said second portion.
2. A device in accordance with claim 1 wherein said wheel is mounted on a first shaft, a mating wheel having a flat surface mounted on a second shaft parallel to the first shaft, said wheels being aligned so as to score doublefaced corrugated paperboard fed therebetween.
3. A device in accordance with claim 1 wherein said wheel is made of one of the following: plastic and metal, and the pitch of said relieved areas being about 24.
4. A device in accordance with claim 1 wherein the land areas between adjacent relieved areas are longer than the adjacent relieved areas so as to provide a continuity of land area at the inner face between the halves on the scoring surface.
5. A paperboard scoring device in accordance with claim 1 wherein all of said land areas of said first and second peripheral surface portions lie within a curved plane defined by a curved surface of a right circular cylinder.
References Cited UNITED STATES PATENTS 2,223,503 12/1940 Wilson 9358.1
BERNARD STICKNEY, Primary Examiner.