US2120902A - Method of and means for making containers - Google Patents

Description

I June 14, 1938. e. A. MOORE METHOD OF AND MEANS FOR MAKING CONTAINERS Filed Oct. 14, 1935' BY j 3 find/Cow ATTORNEY Patented June 14, 1938 I UNITED STATES PATENT OFFICE METHOD OF AND LIEANS FOR MAKING CONTAINERS George Arlington Moore, Louisville, Ky., assignor' to Humoco Corporation, Louisville, Ky., a corporation of Delaware Application October 14,1935, Serial No. 44,857

9 Claims. (CI. 93-60) This invention relates to flanged articles of ing the same in accordance with the present inmanufacture such as containers made of paper vention; or other fibrous material, and more particularly. Fig. is a top plan view, with parts broken to a method of folding a blank of fibrous maaway, of one corner of a completed article;

5 terial to form a flanged article having angular Fig. 6 is a section taken on line 6-6 of Fig. 5; 5 corners. Fig. '7 is a plan view, with parts broken away,

One of the objects of the present invention is of the female and footing dies employed in a .to provide a novel method of forming a flanged machine for carrying out the method of the article from a flat blank offlbrous or other foldpresent invention; able material. Fig. 8 is a sectional side elevation, with parts 10 Another object of the invention is to provide a broken away, showing an intermediate position novel method of folding the flange and flange of the die members of said machine;'and, corners of an article wherein said comers are Fig. 9 is a sectional side elevation, with parts folded in a novel manner. broken away, showing the positions of the die Still another object is to provide a novel nieth- I members at the completion of the folding opera- 15 0d of forming a container constructed of paper tion.

or other flbrous material and having angular The present invention comprehends a novel corners wherein the side walls are, seamless and method of forming or folding a blank into a integral with the base portion of the container. flanged article, such as a container having two A further object is to provide a novel method or more side walls which intersect at a com- 20 of folding the material of a blank adjacent the paratively sharp angle, as distinguished from a corner of a flange constituted by a turned-up circular or similar curved wall container, wheremarginal portion of said blank whereby the folds in the flange will not only be integral with the are symmetrically disposed with respect to said 1 base of the container but will also be continuous corner. or seamless. Containers thus produced are 25 A still further object is to provide a simple and superior to others of a similar shape heretofore inexpensive method of folding the marginal po p de in t the Walls f the Same are tion of a blank to form a flange or the side walls pervious to air and moisture and the container of a container, said method being adapted to bel n s i s lf to the pa kin f n granular carried out automatically, if desired, by the use stances without danger of leakage. In th illus- 30 of a small number of mechanical parts, the opertrated embodiment, a portion only of an article ation of which does not require the constant ator container having an angular corner is Shown. tention of skilled attendants. by way of example. p v

The above and further objects and novel fea- It will be considered, for the purposes of detures of the invention will more fully appear scrlption, that the illustrations of Figs. 1 to 6, in- 35 from the following detailed description .when elusive, represent but one corner of a rectangular taken in connection with the accompanying container which comprises a blank I! having a drawing. It is to be expressly understood, howcentral or base area l3 and a margin or flange ever, that the drawing is for the purpose of illust n 14 u r und s d a area- Preftration only and is not designed as a definition erablyr along line l5 prior to the folding operation to of the limits of the invention, reference being primarily had for that purpose to the appended be hereinafter described in order that the upper claims. edges of the corner folds to be formed will be In the drawing wherein like reference charflush w edggs g i'g a thelateris urne up ocons tue es ewals 3:25;: refer to like parts throughout the several of the container a If desired, blankl2 may'besco'red to form an 1 may; f external bead l6 outlining base portion l3 for corner 0 y p y the purpose of facilitating thefolding of said tio strength to the completed article or container.

n; E- 2 is a similar View of the bottom outer To facilitatethe folding of the corner areas inface of the blank of Fi 'cluded in the right angle between lines a and e,

Figs. 3 and 4 show successive positions assumed the blank may also be scored along lines a to e.

the corners of the blank are trimmed 40 carrying out the method of the present invenblank, and for giving increased rigidity and 50 0 y the blank 1 F 8- 1 in h Pr s of 1' l inclusive, scores a, c and e producing slight 55 beads on the lower face of the blank, and scores b and d producing beads on the inner face thereof. As will hereinafter appear, however, none of the above described scores are essential elements in-practicing the present invention, but are merely illustrated and described as elements of a preferred embodiment.

In paper containers, and containers comprised of like materials heretofore provided, the corners are weakened by the provision of a seam in the flange or side walls thereof at or near said corners. In other prior art containers, a single thickness of material is employed at the corners, thus rendering the same susceptible to crushing under slight stresses, particularly in those wherein the material is weakened by the necessary breaking down of the body or fabric thereof when the same is bent to form said corners. In many containers of the latter type, additional pieces of fiber or tape are secured about the corners' thereof by means of staples or a suitable adhesive for the purpose of reinforcing the same in some degree, but this entails extra expense and labor. By the method of the present invention, a container having reinforced, seamless angular corners in the side walls thereof and having said side walls integral with the base of the container is adapted to be readily and inexpensively made from a single blank of material. The novel method proposed comprises folding the marginal portions I4 of blank I2 along the line or outer edge of. score IIi into a position substantially perpendicular to base portion I3, thereby forming the side walls of the container. Simultaneously with the folding of said side walls, the corner area included between lines a and e of the margin I4 of the blank is creased and folded along each of the lines a to e inclusive. Each of creases a, c and e approaches a vertical position above the corner of base area I3, while creases b and d are caused to move inwardly at a greater rate than the other three and beyond the vertical, thereby forming two corner folds I, 2 and 3, 4. During the formation of said corner folds, creases b and d are preferably guided in diverging paths so that the upper or inner surfaces of segmental areas I and 4 'may be brought into engagement with the side walls I4 adjacent said surfaces and at opposite sides of the corner.

For the purpose of maintaining .the flange and corner folds in position after the same have been formed, a suitable adhesive is applied to the inner -or upper faces of segmental areas I and 4 (Fig. 1) which, as already noted, are caused to engage the side walls I4, and to the outer faces of segmental areas 2 and 3 (Fig. 2) which engage the outer surfaces of areasl and 4, respectively. The adhesive employed is preferably a thermoplastic lacquer adapted to be activated by heat and pressure without the application of a solvent. When said adhesive is rendered tacky by heat and pressure is simultaneously applied to the folds, the engaging surfaces of said folds and side walls are substantially welded together.

One form of the novel mechanism for carrying out the method above described is illustrated in Figs. 7 to 9, inclusive, only that portion of the machine employed for folding one corner being shown. In the form illustrated, the machine comprises a female die member I! having a yieldingly supported footing die I8 engaging the inner walls thereof and adapted to reciprocate therein, a male pressing die I9, and a folding and stripping die 20 surrounding andcontacting said pressingdie. Any suitable mechanism, many of which are well-known in the art, may be provided for imparting the desired reciprocating movement to dies I9 and 20, and since such actuating mechanism constitutes no part of the present invention, it is believed to be unnecessary to illustrate and describe the same.

Female die I1 is provided with a central opening, the lower inner walls 2| of which are vertical and are adapted to position and guide footing die I8, the upper face of which corresponds in size and shape to the bottom of the container or article which it is desired to make. ,The upper inner walls 22 of die I! are inclined upwardly and outwardly from vertical walls 2I for the purpose of initiating the bending of the marginal portion I4 of blank I2 in the formation of the flange or side walls of the container being produced, the width of inclined surfaces 22, as seen in Fig. 8, preferably being somewhat greater than the width of flange I4 of blank I2. The angle of inclination or slope of walls 22 is shown in the drawing to be substantially 45, but any suitable degree of inclination may be employed, depending on the weight and quality of the material constituting the blank to be folded.

In order to crease the corner areas of the marginal portion of blank I2 along lines a to e, inclusive, as desired, and to initiate the folding of the same in the manner above described, each of the corner areas of the inclined walls 22 of female die I1 has two pyramidic raised portions I, 2 and 3', 4'. Preferably, the surface along lines a and e, which bound the corner areas of inclined walls 22, and line 0, which in the form shown bisects said corner area, have the same inclination as said walls, whereas lines b and d are inclined at a greater angle with the horizontal. The operative surfaces I and 2' of one of the pyramidic raised portions slope downwardly in diverging directions from line or edge b to lines a and 0, respectively, and surfaces 3' and 4' of the other pyramidic raised portion slope downwardly in the same manner from line or edge d to lines 0' and e, respectively. Line .0 is thus the line of intersection of surfaces 2' and 3', and lines a and e' are the lines of intersection between surface 22 and surfaces I and 2', respectively. The angle of inclination of lines b, c andd' and hence the lateral slope of surfaces I, 2', 3' and 4' will of course depend upon the slope of walls 22, said slopes bearing such relation to one another that when the margin I4 of blank I2 has been folded to the full line position shown in Fig. 8, the combined areas of surfaces I to 4', inclusive, will accommodate the corner area of said margin without wrinkling the same or placing any portion thereof under tearing pressure.

Folding and stripping die 20 cooperates with female die IT to bend and conform the margin I4 of blank I2 to the shape of the various inclined siu'faces of die I! above described, and to crease the comer areas thereof along lines a to e, inclusive. The lower surface of folding die 20 is machined to cooperate with the upper portion of die II, the lower face of said folding die being inclined in the same manner as are walls 22 of die I! and having recesses therein complementary to pyramidic portions I 2', and 3', 4'. When die 20 is moved downwardly to the position shown in Fig.8 with the margin I4 of blank I2 interposed between it and the female die I1, it will be seen that the marginof said blank will be turned up at an angle to the base portion I4 and the corners will be creased and the folding thereof initiated substantially as illustrated in- Fig. 3 of the drawing.

For the purpose of completing the corner folds l, 2 and 3, 4 and for directing or guiding the same into engagement with the adjacent sidewalls II at opposite sides of the corner when said walls are drawn into vertical position, a recess 23 extending a short distance on each side of the internal corners of female die I1 is provided. Said recess is bounded by two triangularly shaped walls 24 which have the same direction of slope as walls 22 but a much greater degree of slope than said latter walls, and by two walls 25 which are included in planes perpendicular to vertical walls 2! of die and slopedownwardly from the extremities of said recess toward the corner of die I]. When either die H3 or I9 is in position to bound the recess 23, a pyramidal cavity is formed in which the corner folds of the container are adapted to be guided and pressed into final position.

Pressing die i9 and footing die iii are adapted to operate within dies l1 and 20, the dimensions of said pressing die in a horizontal plane being less than those of the footing die by an amount equal to twice the thickness of blankl2. Dies I8 and I9 serveto clamp blank l2 in position and to carry the same downwardly into die I! whereby flange M of said blank is drawn and folded in the manner heretofore described. If desired, groove l6 may be impressed in blank l2 by the operation of die members I!) and I8, the former being provided with a peripheral bead 26 on the face thereof, while the latter has a groove 21 adapted to cooperate with said bead. Groove 21 is preferably sufliciently large to accommodate bead 26 and the material of blank l2 which forms bead l6 so that the central portions'of dies l8 and I9 will engage opposite faces of said blank during the flange and corner folding operation to thereby firmly clamp the blank in position.

In the operation of the above described apparatus, blank I2 is placed on top. of female die I 1 and footing die l8, which latter is normally held in the dotted line position (Fig. 8) by suitable spring means (not shown), the initial position of said blank also being shown by dotted lines in Fig. 8. Pressing die l9 and folding and stripping die 2|] are then moved downwardly together, bead 26 of the latter first engaging blank l2 to form groove l6 about the base portion l3 of the blank. Upon further downward movement of the,pressing and folding dies,footing die I8 is also forced downwardly and marginal portion ll of blank I2 is drawn toward a vertical position within female die l1. When the parts have reached the full line positions shown in Fig. 8, margin H of the blank is clamped between folding die and female die l1, whereby the corner areas a, e of said margin are definitely creased along lines a. to e, inclusive, and the entire marginal portion is turned up to substantially the position illustrated in Fig. 3. Folding die 20 is thereupon withdrawn (Fig. 9) to free margin ll of the blank as pressing die l9 continues its downward movement, drawing flanges l4 into vertical position between die l9 and the vertical walls 2| of die II. This continued downward movement of the pressing and footing dies and consequent drawing of flange i4 causes creases a, c and e to move naturally into substantial coincidence in a substantially vertical position directly above the corner of base area I3, which movement in turn causes the leading edges or creases b and d of folds i. 2 and 3, 4, respectively. to engage the sidewalls shown in Fig. 5. Due to the slope of walls 24,

each increment of downward movement of die l9- after the folding of the flange is completed results in the application of a lateral outward pressure against the corner folds. Simultaneously with the application of such pressure, heat may also be applied to the folded portions by suitable heating means 28, such as steam conduits or electric heating elements, which may be placed in either or both of the die members I! and IS. The thermoplastic adhesive which is placed on portions of the corner areas of the blank prior to the folding operation, as heretofore described, becomes tacky by the application of said heat and the pressure causes the same to flow into the pores and crevices of the material and weld the engaging surfaces of the folds and side walls together. Upon the retraction of pressing die IS, the upper edgeof the side walls ll of the container engages the lower edge of folding and stripping die 20 which serves to strip the completed container from the pressing die. The container is thereafter removed and another blank is inserted, either by hand or by suitable well known mechanism (not shown).

There is thus provided a novel method of forming, from a blank of fiber or like material, a container having angular corners and seamless side walls integral with the base portion or bottom thereof, said side walls thus being impervious to air and moisture and also leak-proof. The novel methodof folding the corners of said blank also results in the formation of a reinforced corner structure. There is also provided novel means for practicing said method, which means is inexpensive and lends itself readily to largescale production.

Although only one embodiment of the invention has been illustrated and described, it is to be expressly understood that the same is not limited thereto but that various sizes and shapes of articles or containers may be made by the novel method comprehended. Itwill also be understood that the corner folds I, 2 and 3, 4 may be folded to engage the outer surfaces of walls ll, if desired. Various changes may also be made in the means employed in carrying out the meth- 0d of the invention, as will now be apparent to those skilled in the art. Reference will be primarily had to the appended claims for a definition of the limits of the invention.

What is claimed is: 1. The method of making a flanged article from-a blank which consists in drawing the marginal portion of the blank to form a flange and define a rectangular base area, the flange being adapted to' form four side walls of the article, drawing the portions of the flange intermediate each side wall along-five lines radiating from each corner of the base area gular folds at each corner, and simultaneously welding together the material of each fold and to form two trianthe fold to the side wall to form reinforced and tainer, and simultaneously drawing the corner areas of said marginal portion, said areas being first creased and thereafter drawn to engage said side walls at each side of the corners of said container, while welding the drawn areas to the side wall at each side of the corners of the. container.

3. In combination, a female die, a rectangular male die adapted to extend into said female die, and a second male die surrounding said firstnamed male die, said second male die and said female die having coacting surfaces for forming folds in a blank at the corners of the latter and said female die having recesses at the corners thereof for receiving the folds formed in the blank by said second male die and the female die.

4. In combination, a female die having an opening with perpendicular side walls therein, a male die adapted to extend into said opening, and a die member surrounding said male die and adapted to move relatively thereto, said die member and female die having coacting surfaces adjacent the intersection of said perpendicular walls for forming folds in a blank and the walls of said female die being cut away adjacent said intersection to provide a recess for receiving the folds formed in the blank by the coacting surfaces of said die member and female die.

5. In combination, a female die, a male die adapted to be moved to draw a .blank into said female die, and a die member surrounding the male die, said die member and female die having coacting surfaces for forming triangular folds in said blank and said female die having portions of the walls thereof cut away to provide a recess for receiving said folds as the male die moves into the female die.

6. The method of making a flanged article from' a blank which comprises drawing a marginal portion of the blank to form a flange having an angular corner and forming adjacent side walls of the article, drawing the portion of the flange adjacent said corner along five lines radiating from the base of said corner to form two triangular folds, and simultaneously pressing the adjacent surfaces of each fold together and the folds against the side walls to form reinforced and seamless corners.

7. The method of making a container which comprises subjecting a blank to the action of cooperating male and female die members whereby a marginal portion of said blank is progressively drawn into flanged relation with the central portion thereof to form the side walls of the container, and simultaneously drawing a corner area of said marginal portion, said corner area being first creased and thereafter drawn to engage said side walls at each side of an angular corner of the container.

8. The method of forming a container from a blank which comprises applying a thin, dry film of thermoplastic material having adhesive prop erties to said blank, drawing the blank into the desired shape, simultaneously drawing portions of the blank into overlapping relation, and applying heat and pressure to said overlapping portions for activating said thermoplastic material and pressing the same into the interstices of the engaging surfaces of said overlapping portions.

9. The method of forming a container, having a bottom and side walls, from a blank comprising fibrous materials which includes applying a thin,

dry film of thermoplastic adhesive to portions of said blank, die drawing the blank to form said side walls and to overlap portions of the latter, and applying heat and pressure to the side walls for activating said adhesive and pressing the same into the interstices of the overlapping portions of said side walls.

GEORGE ARLINGTON MOORE.

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