US2727444A - Container folding machine - Google Patents

Description

7 Sheets-Sheet 1 Filed April 1, 1950 INVENTOR RRY K. WETHE ATTORNEY 2. s ww 3 4 8 H M 4 2 J y w W Y 4 w 6 4 a u O 2 0 2 f 2 lo I 6 (2 2L E 6 2 \k Q Q o 5 RFIIIIIIIIV Dec. 20, 1955 H. K. WETHE CONTAINER FOLDING MACHINE 7 Sheets-Sheet 2 Filed April 1', 1950 INVENTOR Dec. 20, 1955 wETHE 2,727,444

CONTAINER FOLDING MACHINE Filed April 1, 1950 7 Sheets-Sheet 3 INVENTOR HARRY K. WETHE Dec. 20, 1955 H. K. WETHE CONTAINER FOLDING MACHINE 7 Sheets-Sheet 4 Filed April 1, 1950 m T m V w HARRY K. WETHE Hy 5 LATTORNEY Dec. 29, 1955 H. K. WETHE CONTAINER FOLDING MACHINE 7 Sheets-Sheet 5 Filed April 1 1950 fig Dec. 20, 1955 H. K. WETHE CONTAINER FOLDING MACHINE 7 Sheets-Sheet 6 Filed April 1, 1950 FIG.

INVENTOR HARRY K. WETHE WWW A TTORNE Y Dec. 20, 1955 H. K. WETHE 2,727,444

CONTAINER FOLDING MACHINE 7 Sheets-Sheet '7 Filed April 1 1950 INVENTOR HARRY K. WETHE ATTORNEY United States Patent CONTAINER FOLDING MACHINE Harry K. Wethe, Webster City, Iowa, assignor, by mesne assignments, to Package Machinery Company, East Longmeadow, Mass. a corporation of Massachusetts Application April 1, 1950, Serial No. 153,433

9 Claims. (Cl. 93-51) This invention relates to improvements in machines for making containers or cartons from blanks by a series of folding operations.

The invention more specifically relates to machines which are provided with blanks of paper, pasteboard, laminated material and the like to fold finished cartons. The blanks are pre-cut and have a bottom, with side and end walls hingedly attached thereto to be folded at right angles to the bottom to erect the carton. The blank has a continuous web portion at the corner between the ends of the side wall and end wall which must be broken inwardly between the walls. The end walls have an extension flap hingedly attached along the upper edge which functions to secure the carton walls in erected form by being tucked down within the box between the side walls to lie over the infolded web portion holding it flat against the inside of the end wall to support the erected walls.

The invention finds embodiment in'a folding machine which forms the above described blank into a container and is especially suited to the type of machine which erects the side and end walls by means of a plunger pushing the carton blank down through stationary folding dies and employs tucking elements which fold and tuck the end wall extension down into the container against the inner side of the end wall.

An obiect of the invention is to provide a machine which will successively and automatically fold a series of containers by receiving a fiat carton blank, performing a series of folding operations to transform it to a complete erected container and eject the completed container to receive and fold a succeeding container.

A further object is to provide a machine which will rapidly fold a carton while insuring accuracy in forming the fold lines and proper timing of the successive folding of the carton elements, and which will correctly infold the carton web portions insuring their proper positioning V timed relationship to the other working parts and which will allow convenient and rapid adaptation to the folding of various length containers.

These and other objects will become apparent in the full and complete disclosure of invention in the specification taken in connection with the accompanying drawings in which:

Figure l is a plan view of the carton folding machine;

Fig. 2 is a sectional view of the mechanism taken along line 22 of Fig. 1'

Fig. 3 is a sectional view of the mechanism taken along line 3-3 of Fig. 2;

2,727,444 Patented Dec. 20, 1955 Fig. 4 is a perspective of the machine having portions removed for clarity showing the plunger forcing the blanks through the folding members to fold the carton;

Fig. 5 is a perspective view of the mechanism of Fig. 4 at a later point of progression of the plunger descent;

Fig. 6 is a perspective of the mechanism having portions removed for clarity and being at a later point of progression of the plunger descent than Fig. 5;

Fig. 7 is a sectional view of the mechanism taken along line 77 of Fig. 2 as the plunger has partly descended in the forming well;

Fig. 8 is a sectional view of the mechanism of Fig. 7 after the plunger has descended and has begun ascending;

Fig. 9 is a perspective of the machine having portions broken away for clarity taken from the inside corner of the carton as the extension flap is about to be folded into the carton;

Fig. 10 is a perspective view of the mechanism of Fig. 9 at a later point of progression of the folding of the flap;

Fig. 11 is a perspective View of the mechanism of Fig. 16 as the flap completes its folding;

Fig. 12 is a perspective of the machine with one end broken away, illustrating the operation of the linkage driving the mechanism which tucks in the extension flap; and

Fig. 13 is a perspective of the mechanism having portions removed illustrating the driving linkage for operating the elements of the mechanism in timed relationship.

in the drawings illustrating a machine embodying the preferred form of the invention, Fig. 1 shows a flat carton blank 16 before folding. The center panel of the blank forms the floor or bottom 18 of the carton. Side walls 19 are foldably attached to the sides of the bottom along fold lines 2%. The side Walls are comprised of outer sheet 21 connected to the carton bottom and an inner sheet 22 which is an extension of the outer sheet being attached thereto along the top edge 23 and folded down to be glued face to face therewith. The formation of this double side wall is completed before the blank is presented to the present machine. End Walls 24 are foldably attached to the bottom along the fold lines 26. The end Walls have extension tucking flaps 28 foldably attached along the upper edge 3! A continuous extension between the ends of the side and end walls forms a web 32 at the corner of the container blank which must be broken inwardly along the diagonal fold line 34 to fold the carton. The web is attached to the end wall along fold line 36 and to the side wall along fold line 38. The various fold lines may be scored or perforated to aid the folding operation. The end wall extensions have laterally extending triangular shaped ears 42 attached to the tucking flap along line 43. When the carton is folded, the diagonal edge 44 of these cars locks underneath inclined edge 46 or" the inner sheet 22 of the side wall thereby securing the tucked end wall extension flap in place as best shown in Fig. 11. A narrow flap is attached along the top edge 47 of the extension flap to lie on the bottom of the carton to add rigidity to the carton.

In addition to the elements of the carton illustrated, modifications may exist in the structure, and the features of the invention may be adapted to machines which will fold other and varied types of cartons.

The machine embodying the present invention for folding a carton from the illustrated blank is shown with the plunger 48 poised before pushing the blank down through the stationary folding dies in Figs. 1, 2 and 3. The plunger is a rectangular block having a base 50 the size of the container bottom. Each end has a vertical central raised portion 52 and the sides of the plunger have vertical channels 54 for purposes which will later appear. A wear plate 55 is carried in each side having ture than the end folding dies.

its surface flushwith the wall and may extend slightly above the plunger wall. The plunger is carried for its travel by a power actuated U-shaped arm 56 sliding on a pair of vertical guide rods 58. The guide rods are mounted on the main frame 59. A pair of horizontal frame members 60 is attached to the main frame and carries the container folding die elements. The container blank is positioned beneath the plunger by being slid along a pair of ways 62, mounted on members 60 and having vertical guides 64, until the forward edges of the blank strike the blank positioning steps 65. Directly beneath the plunger is the rectangular opening termed the forming well 66 which is defined by the arrangement of stationary folding members or dies also carried on frame member 60 and positioned to surround the plunger with a small clearance as it pushes the carton blank downwardly.

At each end of the folding well is an end wall folding die 68 and at each side is a side wall folding die 70, the dies having inwardly and downwardly curved convex surfaces. The dies are mounted to have their upper surfaces in the same horizontal plane so that all walls of the carton will begin folding simultaneously. The downwardly curved shoulders of the side wall dies lead to vertical walls 71 which form the side walls of the lower part of the forming well. The end walls of the lower well are formed by the tucker plates 72 which are upright in their normal position. Stationary vertical abutment plates 74 are below the tucker plates to complete the lower forming well enclosure.

An important feature of the invention resides in providing the side folding dies with a sharper radius of curva- This greater side curvature folds the side walls more rapidly than the end walls in order to assure positioning the infolded web against the end wall and preventing the possibility of its being positioned against the side wall.

Positioned at each corner of the well between the end and side wall dies and lying in a vertical and substantially diagonal plane is a corner infolding or breaking blade 76 which has a downwardly and inwardly curved edge 78 to break the web corners of the carton inwardly as the plunger pushes the blank between the curved end and side dies.- The curvature of the blade is preferably slightly greater than that of the side wall dies to infold the web along the diagonal line 34 at a rate sufiicient so the web will be folded inwardly along its diagonal fold line and thereby be forced inside the box as the walls are folded upwardly. The upper edge of the blade preferably lies at the same level as the folding dies, thus beginning the breaking of the web corner inwardly simultaneously with the folding of the walls. By positioning the folding blades and side and end folding dies at the same level, the moment the carton begins descending, all portions will begin to be folded at the same time, thus eliminating unnecessary travel of the plunger.

As the plunger moves in its descending path into the forming well 66 the dies 68 and 70 begin forcing the walls 19 and 24 up against the ends and side of the plunger and the breaking blade begins forcing in the corner webs 32. This action is best shown in Fig. 4. As the corner web is broken inwardly by the blade, the folding of the side wall along line 22 is more rapid than the folding of the end wall along line 26, thereby directing the infolded corner web section toward the end Wall. Thus the web will fold more rapidly along its line of attachment 36 to the end wall, than along line 38 of attachment to the side wall. This is necessary if the folding of all parts is to be concurrent and the web is to be folded to lie against the end wall, because fold line 36 must be folded through 180 while fold line 38 will only be folded through 90 in the same time interval. By the control of the rates of folding of the carton elements along their fold lines, all elements are sure to be positioned in their correct relative position.

As above stated, I have provided a method of folding the box by causing the carton side wall to bend upwardly more rapidly than the end wall, while concurrently breaking in the corner web, thus folding the web along its line of attachment to the end wall at a greater speed than along its line of attachment to the side wall. This has caused the inbroken web portion to be directed to lie against the container end wall. This method is shown accomplished in the most efiicient and preferred form in the present embodiment by using dies of different radii positioned at the same level. However, this method of folding could also be accomplished, for example, by movable dies, manual folding, or other suitable means.

After the infolded web has been directed to lie to the right of the plunger corner 49, the folding of the diagonal fold line 34 and the fold lines 36 and 38, as shown in Fig. 5, are completed by being pressed between the plunger end wall 53 and the die 68 as the plunger descends and the space between the dies and wall becomes narrowed.

The unique arrangement of folding elements performs an additional function as the plunger descends, as is illustrated in Fig. 8. The blade 76 is diagonally positioned adjacent the end of the end wall folding die 68 with a narrow space therebetween sufficient to allow passage of a thickness of carton material. As the carton descends, the ears 42 are gradually bent back by the rounded upper edge of the folding blade and the curved edge of the die 68 pressing against the carton end wall creases the ears along their line of attachment 43 to the flap 28. This pre-creasing assures that line 43 will be positioned in the proper place and improves the condition of the completed carton.

When the plunger reaches the bottom of its stroke, it is necessary to strip the container from the plunger and support it rigidly and accurately while the end wall extensions are tucked into the carton. Projecting through the vertical die wall 71 into the path of the plunger travel are stripper fingers 80 (shown best in Figs. 2, 8, 9, 10 and 11) arranged two on each side. Each finger is fixed to the lower arm 82 of a bell crank 84 pivotally carried on a horizontal rod 86 fixed on the frame. The fingers are held in the plunger path by the action of a spring 88 connected between the upper crank arm 90 and the frame. The stripper fingers are positioned to have their lower surfaces rest on the edge of the carton and are preferably spaced along the top edge of the carton a distance from the end of the carton equal to the carton height. The upper face 92 of the stripper finger is sloped inwardly to allow it to easily ride sideways away from the plunger. The sloped face and the location of the fingers with respect to the carton end perform a second function which will later be explained.

Also projecting through each vertical die wall and into the path of the descending plunger slightly above the stripper fingers, is a rounded carton release lug 94 (shown best in Figs. 2 and 3) which is fixed to a second support carrying a bell crank also pivotally suspended on the horizontal rod 86. The lower arm 98 of this crank carries a carton supporting shoe 100 which extends underneath the carton and extends the length of thecarton, supporting it and clamping it up against the stripper fingers. The upper arm 102 of the support carrying the bell crank has a tension spring 104 between it and the frame urging the shoe into the plunger path up against the carton bottom.

It will be noted that since the crank carrying the sup porting shoes is pivoted at the side of the well, the shoes contact the blank to grip it with an upward as well as an inward motion, thus clamping it tightly up against the stripper fingers and holding the carton securely in fixed position.

In operation, as the plunger descends, the lower edge strikes the projecting carton release lug 94 which cams sideward to move the supporting shoe 100 to the side of the forming well as is best shown in Fig. 7. This removes the support from below the carton 105 which has been left in the forming well after being completed on the previous folding cycle. The carton will remain suspended without the shoe support because of the friction between the carton side well consisting of and end walls and sides of the forming the vertical side walls 71 and the abutment plates 74. The plunger 43, continuing in its descent, next strikes the stripper fingers 80 camming them to the side of the plunger pa The base of the plunger carrying the new carton will then strike the top edge of the previously completed carton pushing it out below the ejected carton 1'35, shown ejected in Fig. 8.

As the plunger reaches its lowermost position, shown in Fig. 3, the stripper finger 80, snaps over the top edge 23 of the container into the vertical channel 54 of the plunger. The wear plate 55 extends above the plunger wall a distance sufficient to hold the carton release lug depressed when the plunger is at the bottom of its descent. When the plunger ascends, the stripper fingers riding in the plunger channels strip the carton from the plunger (shown in Pig. 8) where it remains temporarily supported by the friction of its walls against the sides of the well.

As the plunger moves upwardly, the carton release lug 94 rides on the wear plate until the plate clears the release lug 94, allowing the supporting shoes 100 to snap upward under the container, thereby clamping it rigidly up against the stripper fingers 80. It will be noted that the distance from the base of the stripper finger 80 to the top of the supporting shoe 100 is exactly equal to the height of the sidewall 19 of the carton in order to clamp the container securely and in exact position for the operation of tucking the end wall extension flap inside the carton.

Referring now to Figs. shown held between the supporting shoe and stripper fingers after the plunger is withdrawn. The end and side walls of the carton are held in their upright folded position between the abutment plates and vertical die walls.

The carton end wall extension flaps 28 extending above the carton top now lie against the machine end tucker plates 72 which are mounted on cross bars 106 eccentrically carried by pintles 108 lying on either side of the carton end walls as is illustrated in Figs. 2, 9, 10, 11 and 12. The axis of the pintles lies substantially along the top edge 30 of the end wall. The pintles are rotated in pillow blocks 109 (Fig. 12), attached to a bar 111 which is carried by the horizontal frame member 60.

The end tucker plate is positioned in a vertical plane slightly outward from the pintle axis. the tucker plate is above the supporting shoes 100 a distance equal to the height of the container end wall. To tuck the extension of the end wall inside the container the end tuckers are rotated on the pintles through an arc of 180". As the tucker plates rotate through the first 90 (Fig. the extension fiap is folded inward about fold line 30. The lateral cars 42 strike the upper sloped surface of the stripper fingers as shown in Fig. 10. It is evident that the stripper fingers 80 are positioned a distance from the end wall 24 of the container substantially equal to the height of the end wall extension flap 28 or height of container in order that the carton cars will strike the stripper fingers when the extension is being folded. The cars striking the surface of the fingers cam inwardly and backwardly with a gradual motion folding along their lines of attachment 43. This prevents the tabs from being broken or over creased in high speed operation as might be the case if no cam surface were provided and the extension flap were rapidly swung into the container.

The end tucker continues its pivotal rotation until it has pivoted a full 180 to the position shown in Fig. 11, pressing the end wall extension flap 28 tightly against theinner face of the end wall 24 to allow the locking edge 44 of the ears to snap underneath the inclined lock- 9, 10 and 11, the carton is The base 110 of 6 As the push rod 146 is reciprocated 6 ing edge 46 of the side wall. The narrow flap extension 45 bends about its line of attachment 47 to lie against the bottom of the carton. The end tuckers have each end 112 relieved to allow for the extra thickness of the infolded web to press the extension tightly against the inner face of the end wall and thereby obtain a complete crease. It is evident from observing the relationship of the carton elements the fold line 30 must be broken in the proper place or the carton will not lock in completed form. In order to accomplish folding at high speed, the carton must be positioned accurately and held securely with respect to the tucking blade. This has been accomplished by the supporting shoes coacting with stripper fingers to reliably position and support successive cartons.

During the time the tucker blade has been operating the plunger has ascended, a new blank has been positioned over the well and the plunger has again begun its descent, pushing the blank down through the dies. The tucker blades pivot back to vertical position to permit the descending plunger to pass and push out the completed carton.

The mechanism is power driven (Fig. 13) through a drive shaft 114 by a motor (not shown). The drive shaft carries a crank wheel 116 which drives a pitman 118 connected to the U-shaped arm 56 carrying the plunger. As the drive shaft rotates, reciprocating the plunger, the tucker blades are operated in timed relationship to tuck the carton extension flaps into the carton. At the instant the plunger, in its ascent, allows the supporting shoes to move to support the carton, the end tucker blades begin tucking in the extension flap. The blades will have moved into the carton and returned to vertical position by the time the plunger again descends and strikes the carton release lug, causing thesupport shoes .to release the carton. This timed relationship between the plunger and folding block is obtained through the following driving mechanism.

The drive shaft carries a chain 120 and sprocket 122 driving a second sprocket 124 on a second shaft 126 which also carries a disc cam 128. A follower arm 130 pivoted at 132 carries a follower 133 actuated by the cam and thereby drives a connecting rod 134 which in turn oscillates shaft 136 through a crank arm 138. A similar sec.- ond crank arm 140, is secured at the opposite end of the oscillatory shaft 136. Tension springs 142 are connected between the cranks 138 and 140 and the frame 60 to aid in returning the linkage as the follower begins to move to the low portion of the cam. Drive bar 144 is secured longitudinally between the ends of two cranks 138 and 140 to drive two push rods 146 which are attached thereto and are laterally adjustable along the bar by moving the spacing clips 148 which are clamped to the drive bar to prevent the push rods from sliding along the bar.

The upper end of each push rod is pivotally connected by a pin 149 to a crank arm 150 pivotallymounted on the pillow block 109. A second shorter crank .152 is attached to the pintles carrying the tucking blades. A short connecting rod 154 joins the ends of these cranks. through the action of the earn 128 and connected linkage in the apparent manner, the first crank 150 moves through an arc of approximately 90. The second tucker crank 152 being much shorter and connected to the first moves through an arc of thereby pivoting the tucker blade through 180. Fig. 12 shows the relative position of the elements when the blade is in the tucked position and Fig. 13 shows the elements with the blade in the vertical position.

If the machine is to be adjusted for larger containers by replacing the dies and folding assembly with an assembly having folding blades and dies which are spaced further apart, the unit may be changed by removing the bolts 156, one of which is shown in Fig. 12., which hold the cross bars 60 in place. By removing the pins 149, the bars 60 carrying the folding members may be removed and a unit of the desired size may be positioned in the While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and have described in detail the preferred embodiments.

I claim as my invention: 1. In a mechanism for folding cartons from blanks, the combination of a plunger movable to and from the end path and having a blank with side walls folded against the, sides carried thereby,

ears striking said stripper surface to be folded along their line of attachment.

5. In a mechanism for folding containers from blanks having a bottom, side and end walls, and a continuous web portion between the ends of the side and end the combination of a plunger, a l to admit the ing an inner corner rounded toward the well.

6. in a mechanism for folding containers from blanks having a bottom, side and end each side, tion of a plunger, a forming W plunger carrying a blank, a pair of defining the sides of the well and plane at the corners of the the end Wall dies a distance carton material to allow the be folded outwardly.

well, the blades spaced from at least the thickness of the ears to pass therebetween to rest position, carton supporting members positioned below and outwardly of said rest position, springs for moving said supporting members inwardly and upwardly against the bottom of a stripped carton to clamp the latter against the stripper members, and means to move said supporting members to said position position when said plunger charge position. 9. In a mechanism for folding cartons from blanks including a reciprocating plunger and folding means positioned at the sides of the path of movement of the plunger to fold portions of the blank against the plunger as the blank is carried by the plunger past said folding means to a rest position below the latter, spring actuated is in and adjacent said dissaid rest position, carton supporting members carried by the lower ends of said arms below said rest position, springs connected to said arms to move said supporting members inwardly and upwardly against the bottom of a stripped carton to clamp the latter against the stripper members, and lugs carried by said arms and extending into the path of travel of the plunger above and adjacent said rest position and engageable by the plunger and a carton thereon ll for admission of the side folding members outwardly of said discharge a 9 10 to move said supporting members outwardly of said rest 519,531 Gay May 8, 1894 position when said plunger is in and adjacent said rest 1,115,822 Inman Nov. 3, 1914 position. 1,297,748 Streeper Mar. 18, 1914 2,526,824 May Oct. 24, 1950 References Cited inthe file of this patent 5 2,536,530 Bergstein Jan. 2, 1951 UNITED STATES PATENTS 260,800 Strieby et a1. July 11, 1882

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