US2435878A - Method and apparatus for sealing cartons by suction - Google Patents

Description

Feb. 10, 1948. R. M. DUNNING 2,435,878

METHOD AND APPARATUS FOR SEALING CARTONS BY SUCTION Filed Jan. 4, 1945 3 Sheets-Sheet l Feb. 10, 1948. DUNNING 2,435,878

METHOD AND APPARATUS FOR SEALING CARTONS BY- SUCTION Filed Jan 4, 1945 I5 Sheets-Sheet 2 l I l (O .10 @if M A Q 52 JV"; 11 3 v 63 Law W [E E E E I Patented Feb. 10, 1948 U N ITETD STAT ES OFF ICE 23353818 7 METHOD AND APPARATUS no SEALING CARTONS BY SUCTIDN' Robert M. Dunning, St. Paul; Minn, assignorto Waldorf Paper Products Company, Jaul, Minn, a-cor'poration of Minnesota Application January '4, 1945, Serial .No.v571,Z37

.1 My invention relates to an improvement in method of sealing cartons wherein it is desired to produce a tight seal between overlying flaps of a carton through the use'of suction.

In the sealing of tubular cartons of the regular lue end type, it is common practice to fold a pair of closing .flaps or panels into coplanar opposed relationship and to fold flaps from the remaining opposed walls 'over the opposed flaps in superimposed relation. It is usually found that one end of such cartons maybe tightly sealed due tot'he fact that the tubular 'bo'dyis placed over a block or mandrel before the sealing operation takes place, which permits "the necessary pressure to be applied to seal the various flaps in superimposed relation. In sealing the remaining end of the carton, however, after the contents have been placed therein, Jtis d'iflicult to obtain a tight seal due to the inherent tendency of the opposed flaps to curl down into the carton'when moistened by adhesive and further due to the fact that external pressure against the "carton end tends to bend the opposed flaps intothe'c'arton. As a result the sifting of the contents of the carton through this last sealed end often occurs.

Iti's the object oft'he present invention to produ'ce a tightly sealed carton by preventing the innermost flap Or fiapS of the carton Tfrom folding down into the carton. As a result the various surfaces of the superimposed 'flaps are tightly adhered together "and little or no sifting takes place between the adhered surfaces.

A feature of the present invention "lies in the provision of one or a series of apertures in one or more of the iflaps overlying the innermost 'fiap or flaps. This flap containing the aperture or apertures is then placed beneath a suction apparatus which operates through the apertures to draw "the innermost flap or-flaps against the adjacent surface. The atmospheric pressure within the cartonthen acts to push the innermost flap or flaps against the overlying aperture, which flap or fiaps provideatight bond between these parts.

'A feature of the present invention lies in the fact that no unusual carton structure is required to accomplish the desired result and no additional stock is necessary to produce a tightly sealed carton. Thus my carton may be "formed as shapely as "conventional glued end type cartons without the accompanying disadvantages thereof.

-A further feature of the present invention lies 17 Claims. (01. Sis-=6) Y carton is sealed in a benventional type closing and sealingmechanism It is only necessary to add a suction unitto the conventional gluing apparatus in order to cause the sealing operation to "be effected.

A further feature of the present invention in the speed with which tlie sea-ling operation may take place. If airelatively quick dryin adhesive 'isen' pmyedon the cartons, the closing flaps may be folded into carton sealing position and suction applied at the proper time to pull] the innermost flaps againstthe overlying flaps and to produce a tight bond therebetween.

A 'further feature of the present invention resides in the iai'ct that suetion may be intermittently ensues if "it is 'so 'ti'esired. In many instances this arrangement is, desirable; as if the inner carton 'fi'a-ps arnbt pulled into engage-1 ment with their overlying flaps "when suction is actually applied, additional air may be permitted to enter the interior :of the carton-so as to maintain atmospheric pressure witl'iin'the same. The

carton ma then again be subjected to vacuum, which again tendsto draw the innermost flaps against the surfaces to which "they -should he sealed.

Theseand "orther objects 'and novel features of my invention will be more clearly and 'fully set forthfin the f-ollowing-specificat-ion-and claims.

In the drawings -forini'ng"a part of my specification: x I

Figure 1 "is :a perspective 'view of a carton in partially closed position showing one type of aperture in the sealing flaps.

Figure 2 is ,a view similar to Figure '1 showing'a difierent type of aperture which may be-usedin the -sealingflaps. V v

Figure 3 "is "a view similar to "Figures 1 and 2 showing a singleaperturein one-sealing flap and a series "of iwela'tiinalysin'a3l1 apertures in the Outermost sealing flap. u

Figure 4 is a perspective-view of -a'-modified form of "carton showing a "different arrangement o fapertures-in thesealingflaps.

Figure 5 'is a perspective view "of the carton shown "in Figure *lwith the endt-hereof sealed;

Figu're ti is a perspective yieWof-a-earton show ing apertures in but one of the *superin po'sed sealing flaps.

Figured] -is-a view df-t-he carton show'nin Figure-6 with the *apert-ured fiap-in c1osingposit'ion. Figure 8 is a diagrammatic side View of "a can ton filling, erasing and Sealing meGh-a-nism.

Figure 9 is a. erspective diagrammatic new inthe iact that sucnen may be applied 'as'the 55 showingth'esution"apparatusshown in' Figurefi.

Figure 10 is a cross sectional view through a portion of the apparatus shown in Figure 9.

Figure 11 is a modified form of apparatus which may be used in place of that shown in Figures 8, 9, and 10.

The carton A, illustrated in Figures 1 and of the drawings; is provided with tubular side wall structure Ill which is shown rectangular in cross section. The tubular wall structure I0 is provided with two opposed closing flaps II and I2 and a second pair of opposed closing flaps I 3 and [4. In the usual sequence of closing the car- 4 an alternate construction to the cartons A, 13, and C. The carton D includes a substantially rectangular body 35 having a pair of closing flaps 36 and 31 issuing from two opposed sides into coplanar relation and a pair of overlying flaps 1 39 and 40 which fold sequentially over the flaps ton the fiaps H and 12 are usually folded down 4 into coplanar relation as illustrated in Figure 1 of the drawings in full lines, and the remaining fiaps I3 and I4 are then folded to overlie thefiaps Hand [2.

The flap I3 is provided with apair or spatures l5 through which a portion of the flaps. II and 12 are exposed. The exposed portions of the flaps II and 12 are portions spaced from any edge thereof and are shown in approximately the center of the flaps II and I2. In actual practice the apertures 15 may be somewhat closer together than is shown in order to be positioned more closely adjacent the free ends I 6 and I1 of the flaps H and 12 respectively,

- The fiap I4 is provided with a pair of spaced aperturesl9 which register with the apertures 5 when the fiap l4 has been folded to overlie the flap I3. Thus when the carton is sealed as in Figure 5 of the drawings a portion of the flap II and a portion of the fiap l2 are exposed. In Fig ure2 of'the drawings I disclose a carton B which may be substituted for the carton A. The carton B is provided with a tubular body which may be rectangular in shape. From the side walls of the tubular'body 20 issue opposed closing fiaps 2| and 22 and oppositely disposed closing flaps 23 and 24. The flaps 2| and 22 are usually first folded into coplanar relation as shown in Figure 2 The flap 24 is then folded tooverlie the flaps .2! and 22 and to be adhered thereto, and the flap 23 is next folded to overlie the fiap 24. Adhesive is applied to some or all of these fiaps to seal the same together.

;The fiap 24 isprovided with a pair of spaced apertures 25 therein, which expose portions of the flaps 2| and'2'2 spaced from any edge'th'ereof. i The fia'p 23"is provided with relatively small apertures 26- in'reg'istry with the apertures 25. Thus whenthe carton isclosed relatively small apertures 26'may be noted in the uppermost panel 23 while largerapertures 25 are found in the panel24 beneath the panel 23. In Figure 3 of the drawings 1 disclose a carton C which maybe used alternatively with the cartons A or B. The carton D is provided with a tubular wall structure 21 which is shown as rectangular in shape. Two closing flaps or panels 29 and 30 issue from oppositely disposed side walls of the body and flaps 3| and 32 issue from the remaining opposed carton walls to fold over the flaps 29 and 30. The flap 3| is preferably first folded and the flap 32 is preferably uppermost. The flap 3| is provided with spaced apertures 33 which in folded position of the fiap overlie portions of the flaps 29 and 30 spaced from any edge thereof. The flap 32 is provided with a series of relatively small perforations 34 arranged to overlie the apertures 33. The apertures 34 thus communicate with the apertures 33 and permit a partial evacuation of the air from theapertures 33.

. The carton I?! i iusireiee $9 F r also 36 and 31. Spaced apertures 4| are provided in the fiap 39 to expose portions of the flaps 26 and 31 exposed from any edge thereof. Tabs 42 are partially cut from the body of the flap 40, being connected thereto along hinge lines 43. The tabs 42 when elevated or hinged along the fold lines 43 form an aperture in the flap 40 through which air may pass from the apertures 4|. However, when the carton is sealed the tabs 42'may lie in coplanar relationship with the re- .mainder of the fiap, leaving no aperture in the exposed flap. In Figures 6 and '1 of the drawings I disclose a carton E which similarly may be sealed by suction. The carton E includes a tubular body 44 preferably rectangular in cross section which is provided with a pair of opposed sealing flaps 45 and 46, which are shown bent into coplaner relationship. A second pair of opposed flaps 41 and 49 are hingedly attached to the remaining side walls of the tubular. body 44 and are designed to fold into superimposed relation with the fiaps 45 and 46. The flap 41 is provided with a pair of spaced apertures 59 extending therethrough which are spaced to expose portions of the fiaps 45 and 46 spaced from any edge thereof. The flap 49 is designed to fold over the flap 41 when the carton is completely sealed so as to .cover the apertures.

In this form of carton E, the suction is applied after the flap 41 has folded into sealing position as shown in Figure 7 of the drawings and before the flap 49 has been folded to cover the same. Obviously this structure has the advantage of leaving no exposed apertures when the package is completely closed, but on the other hand the structure has the disadvantage of requiring a separate sealing operation to seal the flap 49. In most sealing methods the flaps 41 and 49 are folded at almost the same time and pressure is then applied to hold the flaps in, superimposed relation. With the structure shown in Figures 6 and '1 the flap 41 must first be folded into the position shown in Figure '1, suction and pressure applied so as to seal the flaps 45, 46 and 41 together. Subsequently adhesive must be applied to the fiap 49, this flap folded to overlie the fiap 41, and pressure applied to hold the flap 49 against the sealed remaining end structure.

In Figures 8 and 9 of the drawings I disclose diagrammatically a form of sealing apparatus by means of which the cartons may be filled and sealed. This structure is merely diagrammatic and illustrates the principle, rather than the precise construction of the parts. The sealing mechanism F includes a conveyor 51 which is supported by end pulleys 52 and 53. The top surface of the conveyor is preferably supported by any suitable means such as by spaced rollers or by a fixed support 54 as shown. Cartons such as the cartons A, for example, are fed upon the upper surface of the conveyor 5| and are guided in their path between guide rails such as 55. The cartons successively pass'beneath a sealing hopper such as 56 by means of which the cartons are filled.

After the filling operation the opposed flaps l3 and 14 having apertures therein are folded outwardly into right angular relation with, the

l v i i side walls of carton byw meansoff folding horns. or: bars 51. Thaopposed; flaps H and 1.1 are subjected to: the. action ot 341 10016 shaped plate 59 and a pressing"; foot 802 which actsv to fold the flaps Ill. and 1.2 into" positionshnwn. in Figure 1 of the drawings.

While. the flaps. are, inthe; position shown in Figure 1, the flaps I532 and-{I542 being supported by a folding bar 615, the'cartom top may passibetween. glue wheel's 6d which apply glue: to the-"upper surfaces of the. flaps. l3: and. I14 and: also to the opposediflaps I 1: and IL The. toldingbar- 515 then. acts to fold the. flap: I? intoipositiomoverlymg the flaps II and; 1

A folding bar: 63%: similar to the bar 61,-. but the reverse thereof;- underlies the fiaps; lit. of. theasuccessive cartons; as theystravel along: the; cone. veyor 5 I and acts to: foldthe flaps-s lflijill: osition to overlie the flaps t3; The cartons A then. are fed beneath a cooperating conveyor 64 which acts to apply the. necessary pressure tohold the flaps in their superimposedposition. Pressure rollers 65 may act againsftthe: undersurfaceof the conveyor it so as to. hold: this conveyoragainst the topsof the:cartons. Blocks 66 or cleats may,v.iiidesired; be p-rovided on the conveyor 6A to. engage against the rearmost edgeor the carton soas to cause-.propenregistration between. the cartons: A and-the conveyor belt M.

As. will benoted in Figure 8 of 'the drawings the conveyor- 64: mounted upon end: pulleys: 61 and 69. and is provided-with spaced apertures-1 0 therein designed tooverlie: the center portion of the top of each canton as it successively" moves between the conveyors Niandi I 1 The-apertures- Hl are of large enough siZe-tucommunicatewith the spaced openings I S in the uppermost carton flap M, but th-ese apertures are-somewhat smaller in. area. than the top oi-"the carton so'as-toap ply pressure marginally along allot the edges of the. carton top-closures. TThe cartons are guided from movement laterally-of the conveyors means of suitablefixed guide bars1i.

overlying the upper surface of the-lower por tion of the conveyor 64 I provide a. suction conmg atmosphere'and; them are: subjected to "evade duit 12'. whichv extend-'s iiitocontact with the upper surface of the conveyorbelt Slain opposed relation tothesurfaceaengaging the tops of the cartons A. This suction conduit overlies the belt surface. spaced Efpoints; alongthe length; of travel of thebeltar d permits suction to be communicatedto the apertures 10 in the conveyor belt. In other :words; air from: within the apertures m and. accordingly the communicat ing apertures I=5i and: |9T-in the topflaps or the carton A may: be partially evacuated byfmeansof. this suction conduit 1 2.

' With referencenovw to Figure 10-of -the drawings it will be noted that thesuction conduit 1 2 is providedvwith a relativelylarge undersurfa'ce 13; in contact with: the conveyor belt M anda relatively narrow suction passage 14; This structure is designed to prevent-timeless of vacuum through communi'cation between the passage H and the outer atmosphere as the apertures Hi-in the. conveyor beltpass beneath thesame; It isdesirable try-have the entire aperture- 10 closed}; by the under-surface 1a of the suctijoncondui't 12 before this aperture comes into communication withthe passage" It; This passage 14 may be relatively wide; however; so-asnot to restrict the free passage of-air-therethrough. I

As each successi-ve' carton A passes beneath the undersurfacel3 op -the suction" conduit the apertures-ill are -first sealed fromthe surrounduation. by communication: with the passage 14.. Whiletliepassage to: is in communicationi with the passage 'lt air: will. be: partially evacuated from the apertures 10 and from the: ap:-

ertures l t and I25 the. cartonfiaps lit-and: l3 respectively. action lowers the: pressure above theopposedflaps l t and t2 and permits. the.norma1 atmospheric pressure within the carton. tourge the flaps intocontactwith the-under surface: of the? flaps t3; As. a, result the normal tendency for the-flaps Ht and-121 to curl. inwardly isobviated.

An observation of the carton at. the left side: of Figure 10 shows-that the flaps: H and [2 have curled downwardly to some extent away from.

the overlying: flaps; Ii and I4. This tendency to:

curl inwardly is caused-by the moistem'ng of these flaps bythe adhe'sive. and also by the application of external-pressure againstthe top of 2. the passage 14 in the-surface 13 at the extremeright handendcf the suction conduit is in communicatiom with an aperture 10.- I-hus all of the capacity of thevacuum supply may be directed againsta sing-le cartonor a limited: number of cartons at onetime, requiring a suction pump of much less capacity than would otherwise be necessary. The remainingsuction passages M are closed by contactwiththe conveyor belt 64;

' In -the operation; thus described eachcar-ton is successively subjected tothe. action of suction on itsuppersurface; this suction being inter-- mittent in its action. Between the belt contacting surfaces 13 on the suction conduit 12 the apertures 10- are open-to atmosphere if it is so desired, thus producing a structure in which the tops of the cartons are alternately subjected to partial vacuum and atmospheric pressure. While thisarrangement is not" always essential, it-has certain definite advantages inactual practice.

Inthe event the reduction of pressure above the flaps H and I2- isnOtsllfficiEHt to'move thesefiaps into engagement with the undersurface of the flap l3 when first subjected to the action of vacu um, a passage may be provided between the flaps H or' l2 and [3, which would tend'to'partiallyevacuate the air from the carton; It is-possible' that part of the contents of the carton may beraised by this suction. In order to prevent anysuch difii'culty' in the event the flap il and l2'a-re not entirelyraised 'by the first application of suction, the apertures iiiare thereafter subjected toa'tinospheric pressure; This atmospheric pressure is' transmitted into the interior of the carton through the passage between thefiap I 3 and onepressure 'a'bove the carton may" sufiice' to bring" the carton fiapsi'nto'p'roper sealing relation. As;

a result with my structure even though the flaps are not properly sealed after the first application tion. It is for this reason that I have found the intermittent application of suction to be somewhat advantageous.

In Figure 11 of the drawings I disclose a modified form of construction in which continuous suction is applied to the upper ends of the car-' tons. In this arrangement the cartons A are carried by conveyors similar to the conveyors and- 64 and accordingly. these conveyors have been given similar identifying numbers. The only difference in the structures shown in Figures and 11 lies in the suction conduit, whichin Figure 11 is identified by the numeral 15.

The suction conduit has an undersurface I6 which is in constant contact with the upper surface of the lower portion of the conveyor belt 64. This suction conduit 15 is provided with an air passage 11 therethrough and a series of spacedapertures 19 connect the air passage 11 with the surface 16. The passages 19 are spaced apart adistance shorter than the length of the apertures H1 in the belt 64 so that after the apertures 16 are sealed from the outer atmosphere these apertures are in constant contact with one or another of the passages '19. Thus a continuous reduced pressure is provided above the cartons throughout the length of the suction conduit holding the opposed flaps I i and i2 into sealing relation with the superimposed flap I3.

All of the cartons A through E are provided with a lower sealed end of any suitable type. In-

the various cartons illustrated the lower closures are formed by sealing end flaps in superimposed relation, preferably over a mandrel so that sumcient pressure may be applied to hold the various flaps in sealing relation until the adhesive has set. Any of the cartons A through D, may be sealed in the sealing mechanism shown in'Figures 8- through 11. In the case of the carton D, the par-' tial vacuum above the carton first pivots the tabs 42 upwardly so as to provide a communicating air passage with the apertures 4| so that the air above the opposed flaps 36 and 31 may be partially evacuated.

A slight modification in the sealing apparatus is necessary to seal the carton E shown in Figures 6 and 7. necessary to remove the folding plate 63 from the position shown in Figure 8 and to accomplish this flap folding operation after the carton has passed beneath the conveyor 64. As the mechanism required to fold the fiap M at the end of the suction action is believed obvious, the applicant has not illustrated this modification of the structure.

In the foregoing method the cartons are shown in spaced relation on their respective conveyors. Obviously, however, the cartons may comprise a continuous row of cartons if it is so desired. In such an event any preferred mechanism may be employed to synchronize the conveyor 64 with the cartons on the conveyor 54.

In accordance with the patent statutes, I have described the principles of construction and operation of my method of sealing cartons by suc- In order to seal the-carton E itis only tion. and while I have endeavored to set forth the best embodimentsthereof, I desire to have it understood that obvious changes may be made within the scope of the following claims withoutdeparting from the-spirit of my invention.

I claim:

1. The method of sealing cartons having closures consisting of flap means in surface contact,

certain of the flap means outwardly of an inner. flap means having aperture means therein, the.

method including the' steps of applying a partial vacuum to the closureof the carton in a manner' to urge the said inner fi'ap means into contact" with the next adjacent flap means.

2. The method of sealing a carton-having an endstructure comprised of fiap' means in surface contact, "certain of-said flap means outwardly of an inner flap means having aperture means therethrough, the method including the steps of apply ing adhesive to selected -surfaces of said flap means and applying partial vacuum to the enter-- ture means in the flap means outwardly of the" said inner flap means so as to urge the said inner flap means against the next adjacent flap means.

3. The'method. of sealing a carton having a closure structure comprised of at least two flap means in surface contact, the flap-means next outwardly of an inner flap means having aperture and the next adjacent flap means, and applying partial vacuum to theapertures of the flap means next outwardly fromthe saidinner flap means so as tourge the said inner flap means againstthe next above flap means. 1

4. The method of sealing tubular cartons having sealing flap means foldably connected to the walls thereof and adapted to fold into surfacev contact relation, and aperture means in a flap means outwardly of I an inner flap means, the method. including the steps of folding the said inner flap means across the'open end of the container, folding the apertured flap means upon the said inner flap means; and subjecting the apertures to partial vacuum so as to-draw the said in-' ner flap means against the apertured flap means.

a 5 The method of sealing a tubular carton hav-' ing end flap meanson the walls thereof arranged to fold into superimposed reiationshioone of said flap means above the lowermost flap means having aperture means therein; the method consisting of folding the lowermost fiap means across the open end of the carton, applying adhesive there to, folding the apertured flap means over the lowermost flap means, and applying partial vacuum to the apertures to hold the lowermost flap means against the next adjacent flap means to adhere the same together.

6. The method of sealing a tubular carton hav ing rectangularly arranged side walls, two opposed side walls having iiaps foldable into coplanar relationship, flaps on the remaining opposed side walls at least one of which is provided with aperture means therethrough arranged to flap meansarranged to fold in superimposed rela iv 9 tion, at least one flap means above the lowermost flap means having aperture means therethrough, the method consisting of applying adhesive to selected flap surfaces, folding one of said flap means to extend over the open end of the carton,

folding the apertured flap means over the first folded flap means, one of the adhesive surfaces being between said folded flap means, and applying partial vacuum to the aperture means of the last folded flap means while simultaneously holding the last folded flap means in folded position to draw the first folded flap means against the last folded flap means.

8. The method of sealing a tubular carton having one pair of opposed flap means designed to fold into coplanar relationship and a second pair of flap means on the the remaining opposed side walls of the carton adapted to overlie the coplanar first folded flap means, at least one of said overlying flap means having aperture means therethrough, the method consisting of folding the first named flaps into coplanar relation, applying adhesive to selected surfaces of the flap means, folding the apertured flap means to overlie the coplanar flap means, applying partial vacuum to the apertures while holding the apertured flap means in folded position so as to draw the coplanar flap means into sealing engagement with the apertured flap means.

9. The method of sealing a carton having flaps arranged to fold in superimposed relation, at least one of the flap means above the lowermost flap means having aperture means therethrough, the method consisting of applying adhesive to at least one surface of said flap means between said lowermost flap means and said aperture flap means, and intermittently applying suction to said aperture means to draw said lowermost flap means into sealing relation with said apertured flap means.

10. The method of sealing a carton having superimposed closing flap means, at least one flap means above the lowermost flap means having aperture means therethrough, the method consisting of applying adhesive to a flap surface between the lowermost flap means and the apertured flap means, and alternately subjecting the aperture means to partial vacuum and atmospheric pressure.

11. The method of sealing a carton having a series of superimposed closing flap means, at least one flap means above the lowermost flap means having aperture means therethrough, the method consisting of applying adhesive to a flap surface between the lowermost flap means and the apertured flap means, holding the apertured flap means in folded position and intermittently applying partial vacuum to said aperture means.

12. The method of sealing a carton having a series of superimposed closing flap means, at least one flap means above the lowermost flap means having aperture means therethrough, the method comprising applying adhesive to a surface between the lowermost flap means and the apertured flap means, and alternately subjecting the apertures to partial vacuum and atmospheric pressure.

13. The method of sealing a carton having superimposed fiap means, all of said flap means above the lowermost flap means having registering openings therethrough, the method consisting of applying adhesive to flap surfaces between the superimposed flap means, and subjecting the openings to partial vacuum to draw the lowermost flap means against the next adjacent flap means.

14. The method of sealing a carton having su perimposed flap means, all of said flap means above the lowermost flap means having registering openings therethrough, the method consisting of applying adhesive to flap surfaces between the superimposed flap means, and intermittently subjecting the openings to partial. vacuum to draw the lowermost flap means against the next adjacent flap means.

15. The method of sealing a carton having superimposed flap means, all of said flap means above the lowermost flap means having registering openings therethrough, the method consisting of applying adhesive to flap surfaces between the mospheric pressure to draw the lowermost flap 7,

means against the next adjacent flap means.

16. The method of sealing a carton having at least three thicknesses of flap means in superimposed relation to act as a closure, the intermediate flap means having apertures therethrough, the method comprising folding the lowermost flap means over the end of the carton body, ap plying adhesive to a surface between the lowermost flap means and the apertured flap means, folding the apertured flap means to overlie the lowermost flap means, applying partial vacuum to the apertures to draw the lowermost flap means against the apertured flap means, applying partial vacuum to the apertures to draw the lowermost flap means against the apertured flap means, applying adhesive to a surface between the apertured flap means and the next adjacent flap means, and folding the next adjacent flap means to overlie the apertured flap means.

17. A carton sealing apparatus for use with tubular cartons having end flaps arranged to fold into superimposed relationship, at least one of the flap means above the lowermost flap means having aperture means therethrough, the apparatus comprising means for folding the flap means into superimposed relation, means for applying adhesive between the superimposed flap ROBERT M. DUNNING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Price July 8, 1919 Number

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