US2997931A - Container making apparatus and method - Google Patents

Description

Aug. 29, 1961 w. B. ELAM 2,997,931

CONTAINER MAKING APPARATUS AND METHOD Filed April 11, 1960 2 Sheets-Sheet 1 Z912 Q 329* )7 I? 2; 1 7 94 #12; W M

INVENTOR. W/ZZMM m/mw [MM BY Aug. 29, 1961 w. B. ELAM CONTAINER MAKING APPARATUS AND METHOD 2 Sheets-Sheet 2 Filed April 11, 1960 INVENTOR. W/ZZ/A'M AVA/F040 Fl/9M BY 2,997,931 CONTAINER MAIGN G APPARATUS AND NETHOD William Binford Elam, Jersey City, N..I., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Apr. 11, 1960, Ser. No. 21,262 9 Claims. (Cl. 93-80) The present invention relates to the manufacture of spirally wound container bodies and has particular reference to a method and apparatus for maintaining control over the free dangling ends of individual pull strings which are disposed in a partially completed spirally wound tube in order to prevent the free pull string ends from becoming caught beneath and concealed by an outer ply as the outer ply is added to the partly completed tube during the spiral winding operation.

In United States patent application Serial No. 729,366, filed in the name of Ralph K. Pottle and William B. Elam on April 18, 1958, and entitled Container, there is disclosed an improved easy opening container wherein a pull string is incorporated in a spirally wound container body. In this container body, the pull string comprises a helically disposed portion which is positioned beneath one of the body plies and terminates in an end which passes through an opening the body ply and then extends peripherally beneath a portion of a spirally wound label which covers the body ply. The string end passes between the overlapped helical edges of the label to the outside of the container, where it can be readily seen and pulled to effect the opening of the container.

A method and apparatus for securing these individual pull strings in a body ply web and then spirally winding such web and preprinted label ply into a cylindrical tube from which individual container bodies are subsequently cut is disclosed in United States application Serial No. 19,872, filed on April 4, 1960, in the name of Ralph K. Pottle and entitled Machine and Method for Manufacturing Fibrous Container Bodies.

In the method disclosed in that application, the individual pull strings are positioned, prior to the spiral winding operation, in longitudinal alignment in a body ply web with the major portion of each pull string disposed on one side of the web and the end of each pull string dangling from the opposite side of the web. This web is then spirally wound around a mandrel in such a manner that these string ends are disposed on the outside of the resulting partially completed tube, which almost immediately thereafter is completely covered by a spirally wound label which forms the external surface of the thus completed tube.

The present invention provides a means and method for insuring that the dangling ends of the individual pull strings are not completely concealed by the label web as it is wound onto: the tube, which, at such time is being rotated around the forming mandrel and advanced along it as an incident to the spiral winding operation so that the string ends are carried along a predetermined helical path of travel.

In order to accomplish this, these string ends, as the rotation and advancement of the tube causes themto approach the line along which the label ply makes initial cont-act with the previously wound tube portion, are maintained in a rearwardly extending position to keep them clear of the rear marginal edge portion of the label web to prevent them from being caught beneath the rear portion of the label web. As the continued rotation of the tube then causes these string ends to approach the area at which the leading marginal edge portion of the label web makes initial contact with the partially completed tube, the string ends are projected forwardly in a direc- 2,997,931 Patented Aug. 29,1961

tion which is generally axially of the tube and are maintained in this position as the label web engages the tube. Because of the fact that the length of these string ends exceeds the distance from the leading edge of the label web to the points at which the string ends extend through the body ply, the outer portions of the string ends extend between the label seam and dangle freely from the finished tube. Thus, when the tube is subsequently cut into in dividual container bodies, each body is provided with an exposed string end which is easily grasped for the container opening operation.

An object of the invention therefore, is the provision of a method of preventing the ends of individual pull strings which are secured in a subjacent body Web from being caught beneath and concealed by a subsequently applied label web during the container body winding operation.

Another object is the provision of such a method wherein the pull string ends are first held in a rearwardly extended position to keep them clear of the rear edge of the label web and are then projected to a forwardly extending position so that at least a portion of their length projects forwardly beyond the leading edge of the label web as it is wound onto the tube which carries the string ends.

Another object of the invention is the provision of means for carrying out the method steps of the invention.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses. a preferred embodiment thereof.

Referring now to the drawings:

FIGURE 1 is a perspective view of a finished container which embodies a pull string having a free end which has been positioned in accordance with the principles of the instant invention;

FIG. 2 illustrates a plan view of the preferred form of apparatus suitable for carrying out the method steps of the instant invention, parts being broken away;

FIG. 3 is a vertical section taken substantially along the line 3-3 in FIG. 1;

FIG. 4 is a fragmentary plan view of a portion of the apparatus of FIG. 2, a portion of the label web being broken back to clearly illustrate the manner in which the string ends are projected forwardly in order to prevent them from being caught beneath the leading marginal edge portion of label Web;

FIG, 5 is a sectional view taken substantially along the line 55 in FIG. 4;

FIG. 6 is an enlarged vertical section taken substantially along the line 6-6 in FIG. 5;

FIG. 7 is a plan of a modified form of apparatus wherein air blasts are used to perform the method steps or the instant invention;

FIG. 8 is an enlarged sectional view taken substantially along the line 8-8 of FIG. 7;

FIG. 9 is a plan view showing a modified form of apparatus wherein vacuum alone is utilized to perform the method steps of the instant invention; parts being shown in section and parts being broken away;

FIG. 10 is a sectional view on an enlarged scale taken substantially along the line 1il10 of FIG. 9; and

FIG. 11 is a sectional View taken substantially along the line ll1l of FIG. 9.

As a preferred and exemplary embodiment of the instant invention, FIGS. 2 to 6 illustrate a machine for spirally winding a number of plies of web stock around a stationary winding mandrel 20 to combine them into a spirally wound tube generally designated by the numeral 22. In the instant disclosure,'the tube 22 when completed is formed of four plies of material, the first ply 3 comprising a liner ply 24 which is of a width sufiicient to provide a lap joint on the inside of the tube 22. The undersurface of the liner ply 24 is coated with a suitable adhesive (not shown) as it approaches the mandrel 20.

Next comes a heavy body ply 26 which is wound onto the liner ply 24 with its edges in closely abutted relationship. The upper surface of this ply 26 is coated with a suitable adhesive (not shown). A second heavy body ply 28 is then wound onto the ply 26 with its edges abutted and disposed in offset relation to the butted edges of the ply 26. These three plies 24, 26, 28 are passed through an endless winding belt 30 which is conventional in spiral winding machines of this type, and which imparts to the tube 22 the combination of a rotary motion around the mandrel and a forward motion along the mandrel 20 so that any given point on the tube 22 follows a helical path of travel.

The belt operates around a pair of spaced drums 32, 33 which are respectively mounted on vertical shafts 34, 35 which are carried on a pivoted frame 36 in the usual manner. The drums 3'2, 33 are rotated in opposite directions by a main drive belt 38 which operates around a drive pulley 40 which is keyed to a longitudinal drive shaft 42, the drive shaft 42 being suitably connected to the shaft 34 of the drum 32 by means of a pair of bevel gears (not shown). The rotation of the shaft 42 1's also imparted to the drum 33 through a transverse connecting shaft 44.

As best seen in FIG. 2, the body ply 28 has positioned on it in longitudinal alignment a plurality of individual pull strings P. The major portions M of these pull strings P are positioned on the upper surface of this ply 28 and thus are disposed on the inside of the ply 28 when it is wound around the mandrel 20. Each pull string P also includes at its trailing end an integral free end F which extends through an opening in the ply 28 and projects from the opposite surface of the ply 28 so that they are disposed on the outside of the tube 22 as it passes through the winding belt 30.

After the tube 22 passes through the belt 3%, a label web 50 having its undersurface coated with an adhesive (not shown) is guided ontothe top of the mandrel 20 by suitable guides 49 and is wound around the tube 22 in such manner that it completely covers the outside of the tube 22 and provides a decorative and protective label for it. For this purpose, the web 50 may be composed of a suitable material such as a thin foil laminated to a thin paper backing sheet, and preferably has preprinted on it a suitable unitary label design (not shown) which occupies the areas generally indicated by the numerals 52. The label designs are preferably printed on the diagonal, and are successively repeated along the ply 50, the individual label areas 52 {being separated from each other along the diagonal lines 54 which may be real or imaginary and which become circumferential lines on the wound tube 22. It is along these circumferential lines that the cuts are subsequently made which divide the wound tube '22 into individual sections which comprise individual container bodies such as the container body 55 seen in FIG. 1'. The label web 50 is preferably of such width that its leading edge portion overlaps its trailing edge portion in the finished tube 22 to thereby form a helically extending lap seam56. For this reason, the lapped portion 57 need not be printed with the label design. 7

As the partially finished tube 22 emerges from the winding belt 30 and approaches the line, generally indicated by the broken line 58 in FIG. 2, along which the label web 22 makes initial contact with it, it comes into light frictional contact with a brush 59 which is mounted on a shaft 60 which is journalled in a suitable bearing 62. The bearing 62 is mountedron a vertically adjustable bracket 64 which in turn is supported by a frame 66 which is mounted on a pivot pin67. The pivot pin 67 is in 4 turn carried on a base 68 which is bolted to the main frame 69.

The brush 59 is preferably mounted so that its periphery is disposed in rearwardly spaced parallelism with the trailing edge 70 of the label Web 50 as it approaches the mandrel 20, and is disposed in alignment with the string ends F as they are carried along their helical path of travel along the mandrel 20 by the tube 22. The brush 59 preferably is rotated in a direction which is counter to the direction of the movement of the string ends F by a spring belt 72 which operates around a pulley 74 which is keyed to the shaft 60. At its other end, the belt 72 operates around a small pulley 76 which is keyed to a short shaft 78 mounted in the frame 66. The shaft 78 also carries a large pulley 80 which is rotated by a belt 82 which, in turn, operates around and is rotated by a pulley 34 mounted on a long longitudinal shaft 86 which extends rearwardly of the machine and carries at its opposite end a second pulley 88. The pulley 83 is rotated by a belt 90 which operates around a pulley 92 which is keyed to the main drive shaft 42 and rotates therewith.

The brush 59 is positioned so that it lightly engages the surface of the partially formed tube and thus engages and exerts a dragging action on each string end P as it passes beneath it. Prior to this engagement, the string ends F dangle limply from the tube 22 in a generally vertical direction. However, as a result of the dragging action exerted by the brush 59, the string ends F are pulled into a position which is substantially parallel to and rearwardly of the trailing edge 70 of the label web 50, and are maintained in this position during the time the label web 50 initially engages against the tube 22, adheres thereto and is carried forward by the rotation of the tube 22. Thus, the string ends F are maintained away from the label ply 50 and are not permitted to get into a position where they would become caught beneath the rear marginal portions of the label Web 50 and be concealed from sight. It will be obvious that the brush 59 need not rotate to eifect a dragging action. However, rotation of the brush 59 is preferable to even the wear on it and to prevent the accumulation of paper fibres which it may pick up from the tube 22.

As the string ends F are rotated through approximately 270 after passing beneath the brush 59, they pass from the control of the brush 59 and again dangle limply from the outside surface of the tube 22. As

stated, the forward movement of the tube 22 causes these string ends F to follow a helical path of travel. As a result, they again approach the label web 50 as it winds ontothe tube 22. Because of the fact that the diagonal dimension of the label web 50 is approximately equal to the pitch length of the helical path of travel of the string ends F, the string ends F are now spaced behind the leading edge 96 of the label web 50. In order to again prevent the string ends F from being caught be neath the label web 50, a second brush 100 is positioned adjacent the mandrel 20 beneath the approaching label web 50.

The brush 100, as best seen in FIGS. 2 and 3, is disposed beneath the label web 50 and contacts the tube 22 at a point which intercepts the helical path of travel of the string ends F. Consequently, the brush engages each of the string ends F as they are moved past it by the rotation of the tube 22. The brush 100 is rotated in such direction that at the area at which it contacts the tube 22, it is moving in the same forward direction as is the tube, butpreferably at a peripheral speed which is about three times the forward speed of the tube. This rotation is transmitted from the shaft 78 through a pair of, bevel gears 102 to the shaft 104 on which the brush 100 is mounted.

The brush 100 is forced against the tube 22 with a light pressure by a spring 105 which pulls the pivoted frame 66 inwardly toward the mandrel 20. An adjustable stop 106 which engages against a stationary lug 107 is provided to limit the pivotal movement of the carriage 66. A pivoted latch 108 which is engageable against a pin 109 is provided to hold the carriage in outward position when it is desired to hold the brushes 59, 100 in non-operative position.

As a consequence of the forward rotation of the brush 100, the string ends F are thrown forwardly, as best seen in FIG. 4, so that they extend in a direction which is substantially longitudinal of the tube 22. if the brush 100 is spaced closely enough to the line of initial contact 58 between the label web 50 and the tube 22, each string end F will remain substantially in this forwardly extending position until such time as the rotation of the tube carries it past the line 58 with the result that a portion C of the string end F will be caught beneath the label, the remaining portion D of said string end P extending from between the label lap seam 56 and projecting therefrom to the outside of the tube 22. In such case, the concealed portion C will extend substantially axially of the tube 22. If the brush 100 is spaced farther from the line 58, the string end F will have a tendency to sag downwardly by gravity, with the result that the portion C concealed beneath the label web 50 will be inclined downwardly at an angle to the axis of the tube, but the outer end portion D of the string end F will still project from the label lap seam 56 and be exposed to view.

It is preferred, however, to provide means to positively hold the string ends F in their forwardly extended position as they pass the line of contact 58 between the label web 50 and the tube 22. For this purpose, a vacuum head 108 is provided. The head 108 is connected to a suitable source of vacuum such as a vacuum pump (not shown) by a vacuum pipe 109 and is formed with an arcuate opening 110 which closely follows the curvature of the tube 22 and extends from the brush 100 to the line of contact 58 (see FIG. 6) and is spaced just outwardly beyond the ends of the forwardly projecting string ends F. As a result, the string ends F are pulled towards the arcuate opening 110 and maintained in the desired position as the label ply 50 wraps onto the tube 22.

The tube 22 is subsequently severed along the circumferential lines 54 to divide it into individual can bodies 55, each of which contains a properly located pull string having the portion D exposed to view. As seen in FIG. 1, suitable end closures 111 are applied to the body ends to form a sealed package. When the consumer desires to open the container to remove it contents (not shown), he need only pull outwardly on the string portion D, thus tearing through the label ply 52 alone until the tear reaches the point at which the string passes through the body ply formed by the web 28. From thereon, the major string portion M tears helically through both the label ply 50 and the body ply 28, the tear extending for the major length of the body 55. Since the string portion M is positioned directly over the butt joint of the immediately subjacent body ply 26, thereafter only the comparatively thin liner ply 24 holds the body 55 together and the thin ply 24 can be readily broken by a twisting action exerted on the opposite ends of the body 55.

FIGS. 7 and 8 illustrate a modified form of the invention wherein blasts of air are utilized to effect the method steps of the invention. This modification comprises an air manifold 112 which receives a flow of rapidly moving air through a supply pipe 113- from any suitable source, such as a blower (not shown). The air is divided in the manifold 112 by a pair of vertical bafiles 1 14, 116 and is diverted in opposite directions forwardly and rearwardly of the mandrel 20. As seen in FIG. 6, the baffle 114 is curved rearwardly so that it deflects a portion of the air backwardly along the mandrel 20 and blows the string ends F rearwardly to keep them from becoming caught beneath trailing edge 70 of the label web 50. In a similar manner, the baflie 116 is curved forwardly and deflects a portion of the air forwardly along the mandrel 20 so that the string ends F are projected in a forwardly extending direction as they approach the contact line 58 from beneath the label web 50. As seen in FIG. 7, the manifold front edges of the baffles 114, 116 are curved around the mandrel 20 so that they are closely spaced therefrom. Thus, the manifold is effective to direct the string ends F right up to the line 58 at which the label web 50 comes into contact with the tube 22.

FIGS. 9, 10 and 11 disclose another modified form of apparatus wherein the method steps of the invention are effected solely by means of vacuum. In this form, a vacuum nozzle 120 is positioned along the helical path of travel of the string ends F with its opening slot 121 in closely spaced relationship to the tube 22. A vacuum is constantly maintained in the nozzle 12.0 by means of a suitable vacuum pump (not shown) which is connected to the nozzle 120 by a pipe 122. Thus, as the rotation of the partially finished tube 22 causes the string ends F to pass inwardly of the vacuum nozzle 120, a drag is exerted upon the string ends F by the nozzle 120 and they are maintained rearwardly of the trailing edge 70 of the label web 50 as it winds onto the tube 22.. Continued rotation of the 'tube 22 results in the helical movement of the string ends F which brings them into proximity to a second vacuum nozzle 124 which is mounted forwardly of the label web 50 and is formed with a narrow opening 126 which extends arcuately around the tube from a point just beneath the leading edge 96 of the label web 50 to a point spaced forwardly of the initial line of contact 58 between the label web 50 and the tube 22. Because of this shaping of the vacuum nozzle opening 126, the string ends F are quickly pulled to and maintained in the position shown in FIG. 9, wherein they extend forwardly of the leading edge 06 of the label Web 50 as it winds onto the tube 22.

It will be understood that it is not necessary that the outer web 50 be a label web, nor that it be formed with a lap seam, since the method steps of the invention can be utilized to maintain the string ends F free of the superposed ply, regardless of whether such superposed ply be a heavy body ply or a thin label ply and regardless of whether the superposed ply be formed with a lap joint or a butt jointv It will also be obvious that the helical joint of the superposed ply need not be offset from the helical path of travel of the string ends F, but may be positioned in radial alignment with it; also that the method steps can be effected by any suitable combination of brushes, vacuum and/or air blasts, and need not be limited to the specific combinations shown in the drawings.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts of the apparatus mentioned herein and in the steps and their order of accomplishment of the meth od described herein, without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the apparatus and method hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A method of forming spirally wound pull string container bodies, which comprises helically winding a web containing a plurality of longitudinally disposed pull strings having free ends dangling therefrom to form a tube With the ends of said pull strings dangling from the outer surface of the tube, rotating and advancing said tube along a predetermined path of travel, feeding a second web angularly to said tube to bring it into contact with its outer surface and helically winding said second web onto said tube to cover it, maintaining said string ends rearwardly of the trailing edge of said second web as the advancement androtation of said tube causes 2,997,9si A them to approach the area at which said second web initially contacts said tube, and projecting said string ends forwardly along said tube as the continuedadvancement and rotation of said tube causes them to approach the leading edge of said second web at the area wherersaid second webinitially contacts said tube, whereby at least a portion of said string ends are kept from being caught beneathand covered by said second web.

2. A method of forming spirally wound pull string container bodies, which comprises helically wrapping around a horizontal mandrel an inner web containing a plurality of longitudinally aligned pull strings having free ends dangling from said inner web to form said inner web into a tube with the ends of said pull strings dangling from the outer surface of said tube, rotating and advancing said tube along said mandrel to move said string ends along a helical path of travel, guiding an outer web angularly of said tube into initial contact therewith at an area disposed adjacent the top of said tube with the outer web so located that its trailing edge is disposed in forwardly spaced relationship to the adjacent portion of the helical path of travel" of the string ends, projecting said string ends rearwardly of said trailing edge of said outer web as said outer web initially contacts said tube, and projecting said string ends forwardly along said mandrel as the continued rotation and advancement of said tube causes them to approach the leading edge of said outer web at the area where said outer web initially contacts said tube, whereby at least a portion of each tree string end is maintained clear of said outer web.

3. A method of forming spirally wound pull string container bodies, which comprises spirally winding a body web containing a plurality of longitudinally aligned pull strings having free ends dangling from said web to form said web into a tube with said string ends dangling from its outer surface, rotating and advancing said tube to cause said string ends to follow a predetermined helical path of travel, guiding a label web angularly of said tube into contact with its outer surface, said label web being so located as it initially contacts said tube that it straddles one turn of the helical path of travel of said string ends, spirally winding said label web around said tube with its leading edge in overlapping engagement with its trailing edge portion to form a lap seam extending helically along said tube in offset relationship to the helical path of travel of said string ends, maintaining said string ends rearwardly of said label Web as the advancement and rotation of said tube causes them to approach the area at which said label web initially contacts said tube, and projecting said string ends forwardly along said tube as the continued advancement and rotation of said tube causes them to approach the leading edge portion of said label web at the area where said label web initially contacts said tube, whereby only the inner portions of said string ends are caught and concealed beneath said label web and the outer portions of said string ends extend through said label web lap seam and are exposed on the outside of said labelled tube.

8 a r a 4. A machine for forming spirally wound pull string containers, comprising a mandrel, means for'wrapping around said mandrel an inner web which carries on it-a plurality of longitudinally disposed pull strings having free ends dangling therefrom to form said inner web into a tube wherein the string ends dangle from the outer surface of the tube, means to rotate said tube around and to advance said tube along said mandrel to cause said string ends to follow a helical path of travel, means for guiding an outer web into contact with said advancing tube with the trailing edge portion of said outer web disposed in parallelism with said helical path of travel of said string ends at the area of initial contact between said outer Web and said tube, means for maintaining said string ends rearwardly of said trailing edge portion of said outer web at said area of contact, and means for V projecting said string ends forwardly of the leading edge portion of said outer web to maintain at least a portion of said string ends clear of said outer web.

5. The machine of claim 4, wherein the two last named means comprise a pair of brushes engageable against said string ends, one of said brushes being effective in maintaining said string ends clear of said trailing edge and the other of said brushes being rotatable to project said string ends forwardly of the leading edge portion of said outer web.

6. The machine of claim 5 wherein vacuum means are provided to maintain said string ends in their forwardly projecting position after said rotatable brush has projected them forwardly into such position.

7. A machine for forming spirally wound pull string containers, comprising a mandrel, means for wrapping around said mandrel an inner web which carries on it a plurality of longitudinally aligned pull strings having free ends which dangle from the web to form said web into a tube with the string ends dangling from the outer surface thereof, means to rotate said tube around and to advance said tube along said mandrel to cause said string ends to follow a helical path of travel therealong, means for guiding an outer web angularly of said tube to bring it into contact therewith, means operable against said string ends as they approach the trailing edge of said outer Web for deflecting them rearwardly of said Web, and means operable against said string ends as they approach the leading edge of said outerweb for projecting said string ends forwardly along said mandrel so that at least a portion of each of said string ends remain clear of said outer web and exposed on the outer surface of said tube. j p

8. The machine of claim 7 wherein said two last named means project blasts of air at said string ends.

9. The machine of claim 7 wherein said two last named means operate to attract said string ends by vacuum. e

No references cited.

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