US3233528A - Method of carton erection - Google Patents

Description

Feb. 8, 1966 F. c. GROSS METHOD OF CARTON ERECTION 8 Sheets-Sheet 1 Filed May 4, 1964 INVENTOR.

FRANK C. GROSS ATTORNEY.

Feb. 8, 1966 F. c. GROSS METHOD OF CARTON ERECTION 8 Sheets-Sheet 2 Filed May 4. 1964 INVENTOR.

FRANK C. GROSS ATTORNEY.

Feb. 8, 1966 F. c. GROSS METHOD OF CARTON ERECTION 8 Sheets-Sheet 5 Filed May 4. 1964 ATTORNEY.

Feb. 8, 1966 F. c. GROSS METHOD OF CARTON ERECTION 8 Sheets-Sheet 4 Filed May 4, 1964 INVENTOR FRANK C. GROSS ATTORNEY Feb. 8, 1966 F. c. GROSS 3,233,528

METHOD OF CARTON ERECTION Filed May 4. 1964 8 Sheets-Sheet 5 FRANK C. GROSS ATTORNEY.

Feb. 8, 1966 F. c. GROSS 3,233,528

METHOD OF CARTON ERECTION Filed May 4. 1964 8 Sheets-Sheet e INVENTOR.

FRANK C. GROSS ATTORN E Y.

Feb. 8, 1966 F. c. GROSS METHOD OF CARTON ERECTION 8 Sheets-Sheet '7 Filed May 4. 1964 MNN ONN INVENTOR.

FRANK C. GROSS ATTORNEY.

Feb. 8, 1966 F. c. GROSS 3,233,528

METHOD OF CARTON ERECTION Filed May 4. 1964 8 Sheets-Sheet 8 INVENTOR.

FRAN K C. GROSS ATTORNEY.

United States Patent Ofi ice 3,233,523 Patented Feb. 8, 1966 3,233,528 METHOD OF CARTON ERECTION Frank C. Gross, 863 Ridge Road, Wilbraham, Mass. Filed May 4, 1964, Ser. No. 364,390 1 Claim. (CI. 93-36) This application is a continuation-in-part of my copending application, Ser. No. 245,948 filed December 17, 1962.

The present invention relates to new and useful improvements and structural refinements in methods for heat sealing together pieces or sections of paperboard, as in car-ton erecting procedures, by a system which comprehends the prevention of the formation of blisters during the heat sealing and pressurizing operation and the improvement of the heat conductivity and heat sealability of the paperboard, as in the case of carton blanks provided with overall or spot coatings of heat scalable materials.

Historically, in the development work preceding and leading to the present invention, I have been aware of the existence of the problem of blistering, induced by the presence of the heat employed in the heat sealing function, particularly in areas of single plies or thicknesses of paperboard which are clamped between :a pair of metallic members, such as a forming mandrel and a coacting sealing plate, in manner such as to allow the eutrapment of moisture thereat and accordingly to result in the generation of steam from the so-trapped water vapor, all leading to objectionable delamination of the paper board in said areas. Interestingly enough, such condition appears not to exist in areas of double plies or thicknesses of paperboard so clamped between a pair of metallic members.

Incident to this condition and in my solution for its correction, I have discovered that the fluting of the face of one of the metallic members, adjacent the paper board being so sealed and pressured, allows the venting of the so-generated steam sufiiciently so as to preclude the problem ab initio.

Additionally in my developmental work, I have determined that the deliberate and intentioned moisturizing of the paperboard, or of portions thereof, preliminary to the heat sealing and pressurizing phase of the working thereof, leads to improved results in the heating and sealing procedures by way of improving the heat conductivity and heat scalability characteristics, contributing to accelerated working periods, such as carton-erecting cycles, with obvious advantages and economies in time or speed thereby permitted.

Further historically, the developed moisturizing technique was resultant from the research and development work attendant upon the intentional addition of moisture to the paperboard in my effort to aggravate the blistering condition in order better to evaluate and assess the factors inherent therein and to prove the effectiveness of the solution thereof via the avenue of the fluting or grooving above referred to.

The embodiment of the present invention may be briefly described as embracing broadly the concept of a method of securing pieces of paperboard to each other as in the erection of a container blank consisting of the sequential erecting steps comprehending: increasing the moisture content of the pieces of paperboard or certain portions thereof for improving the heat conductivity and heat scalability thereof, moving the pieces or portions thereof to be sealed together into overlapping position as to each other and in clamped relationship between a pair of heated metallic members, and heat pressure sealing the so clamped pieces or portions thereof with one of the heated metallic members being provided with fluted means for allowing the escapement of any generated steam and precluding the blistering of the paperboard.

It also embraces the means answerable to that method which envisions cooperating instrumentalities shown in the form of a carton erecting assemblage for forming a container from a scored carton blank being moisturized or having certain moisturized panels by a means for folding the blank along certain of its score lines and heat sealing together various of the moisturized panels and/ or glue tabs thereof by applying heat and pressure thereto with one of the forming members being provided with fluting for allowing the venting of generated steam sufficiently to preclude any blistering of the paperboard.

In accordance with the teachings hereof, the blank may first be moisturized and the conditioned-by-moisturizing blank, and a liner therefor if one be used, may then be delivered to cooperant instrumentation by means of which sections of paperboard are brought into overlapping relationship as to each other for the heat sealing and pres-surizing function between forming and pressure and sealing members, which forming member is inclusive of means allowing the escape of steam generated from the moisture within the paperboard for the preclusion of the blistering of the paperboard thereat.

While the present invention is envisioned as generally employing the principles, or certain thereof, of the present application, it is to be note dthat the principles of this invention may be embodied in any application where pieces of paperboard are heat sealed together or in any cartonforming apparatus and/ or may be incorporated at a carton forming station in any carton filling or packaging machine.

One primary object hereof is to teach a method aspect of heat sealing paperboard wherewith the sequential steps of the technique may be successfully performed and an apparatus aspect which comprehends a conditioning and erecting and sealing assemblage associated with an apparatus which supports, and supplies movement to, a prime mover, and additionally supports feed mechanisms for delivering a carton blank to a registering station in adjacency to the erecting assemblage, which assemblage is characterized by coacting stationary components fixedly secured relative to the apparatus and movable components reciprocable relative to the apparatus and to the stationary components of the assemblage during operational use.

With a conditioned blank, or conditioned blank and liner positioned relative to the erecting assemblage, and with the prime mover or forming mandrel actuated theretoward, the mandrel clamps the bottom panel of the blank to a blank retainer plate of a bottom panel plate subassembly while the mandrel moves linearly in a cartonerecting direction to effectuate timed articulating movements of end panel folding plates and front and rear panel folding plates of the assemblage and consequent folding of the end and front and rear panels of the carton to cartonerected position. Simultaneously, under conditions of heat and pressure, the overlapping moistened panels are sealed into carton-erected position with the sealing continuing during a retrograde linear movement of the mandrel as the plates of said assemblage travel therewith, carrying the erected carton therewith, under actuation of a return mechanism to return to a normal non-operative position following completion of the carton-erecting cycle. Upon such return of the articulated components of the erecting assemblage, the mandrel continues its retrograde movement whereby to allow the freeing of the erected carton, or carton and liner, from the mandrel by a suitable stripping mechanism.

The invention teaches the moistening and preheating of certain of the carton panels for attaining a conditioning of certain panels or portions thereof which will have been pretreated with a heat sealing medium, the in seriatim folding of certain of the panels and glue tabs thereof, and the deflecting of certain of the panels so as properly to position themprior to a heat and pressure sealing program, all as sequential erecting steps, it being understood that the blank envisioned for use in connection herewith preferentially carries overall or spot coatings of a heat-sealable medium on certain surfaces or portions of the certain surfaces of certain of its panels tobe subjected to the said heating and pressure sealing program during the cartonerecting cycle whereby the erected end product is fully sealed in certain contacting and permanently-bonded areas.

Heating elements for the accomplishment of the heating function are suitably positioned on the end panel folding plates to facilitate the application of heat from the outside of the carton being erected and may also be suitably positioned on the mandrel to facilitate the application of additional heat from the inside of the carton. That is, it is one purpose hereof to provide, in the case of spot coated blanks, as differentiated from overall coated blanks, heat and pressure sealing elements which will be disposed not only adjacent certain of the outside surfaces of the blank but also adjacent certain of the inside surfaces thereof, all so as to accelerate the heat sealing action and to contribute to high erection speeds.

As one salient refinement of the invention, opposite end faces of the mandrel are relieved, each to define a compensating area adjacent a respective carton-sealing area for accommodating the double thickness of the paperboard of a blank resulting from the overlapping of an end panel and glue tabs thereof and allowing a uniform over all contact of the respective folding and sealing plate of the assemblage with the outer surface of the respective end panels of the blank.

Additionally, and because of the fact that under certain conditions of machine speed, temperature, pressure, and moisture content, steam from entrapped moisture is observed to form internally in this defined area so as to cause the paperboard to blister and delaminate, steam vent flutes or grooves are machined into each mandrel end face thereby to obviate the condition by the provision of steam escape means. The flutes or grooves will vary as to number and as to their width and depth according to the thickness of the paperboard of the blank being employed and the size of the carton resulting therefrom.

Another significant object hereof is to provide a cartonerecting apparatus wherein the required heat sealing time is shortened due to a preheating feature wherewith the blank or portions thereof may be heated prior to and during the folding phase of the erecting cycle.

Still anoth r purpose hereof is to teach methods for increasing a machine speed by augmenting the moisture content in the paperboard of the employed carton blanks, the effect being to reduce heat sealing time so as thereby to allow a higher speed of machine operation.

I have determined that the moisture content of the blank is an important factor in the respect that, by increasing moisture content above the normal standard, significant conditions are realized; the so-added moisture assists measurably in the reactivating of the heat-sealable medium on the blank, allows the attainment of a greater bond of its unitable parts, and increases the heat conductivity of the paper board by reducing its insulating properties.

Different methods are envisioned for so increasing the blank moisture content. For instance, the blanks may be sufficiently conditioned merely by the storage of same within a controlled atmosphere of approximately 68% relative humidity for approximately 2 to 3 days preliminary to carton-forming. Failing this, other moistureapplying methods are comprehended and are herein taught whereby to effectuate a direct application of the moisture to certain areas of the blank before it is delivered or While it is being delivered to the registering station adjacent the erecting assemblage. The moisture may be applied through spray nozzles although the employment of roller applicators, wick type applicators, or like types of moisture applicators is comprehended, all in response to the desideratum of dispersing a uniform water film over the surface or surfaces of each of the certain areas of the blank being conditioned.

By such methods, the moisture is applied to one or the other or both of the surfaces of the said certain areas of the blank.

Additionally comprehended isthe use of a suitable wetting agent, in combination with the employed moisturizing medium, for facilitating an accelerated and more effective moisture penetration.

As previously mentioned, the preheating of certain areas of the lank may be accomplished by the use of a heated mandrel within the caiton-being-erected and by the use of heated sealing plates without the carton-beingerected, all for effecting a transferral of heat through the paperboard of the blank by means of conduction to the surfaces to be bonded. By increasing the moisture content, I am able to reduce the inherent insulating properties of the paperboard, thereby to permit the higher machine speeds at lower heat sealing temperatures.

The movable components of the erecting assemblage include a bottom panel plate subassembly which reciprocates linearly and coaxially with the reciprocating prime mover or forming mandrel and has self-aligning or floating characteristics as respects the mandrel. Constituting said subassembly are a bottom plate and a blank retainer plate extendable forwardly thereof, and a pair of end panel and glue tab folding and sealing plates, each disposed at one end of the bottom plate and hingedly secured thereto so as to be movable therewith, and front panel and rear panel folding plates at opposite sides of the bottom plate and hingedly secured thereto so as to be movable therewith.

The suba-ssembly is movable in one direction in response to the carton-erecting movement of the mandrel and in a return direction to their normal rest positions responsive to a return mechanism concomitantly with the retrograde mandrel movement.

The self-aligning or floating capability of the subassembly allows heat-sealing pressure equalization on both ends of the blank during the carton-erection cycle, the subassembly being free to adjust transversely relative to the main axis of movement of the mandrel.

Another chief feature hereof resides in the capacity for discharging an erected-carton from substantially the situs of the blank immediately prior to the initiation of the erecting process. That is to say, the arrangement hereof is not characterized by operation on the known principle of thrusting or pushing an erected carton through a forming section from one side to the opposite side thereof, but rather is characterized by operation on the principle of returning an erected carton to a point adjacent that where the blank is initially disposed preliminary to erection.

The physical embodiments and structural details thereof as herein described and illustrated are indicative of but several of the various, albeit preferred, ways in which the principles of the invention may be employed and in which the component parts may be combined and arranged. However, said embodiments are not'intended to be exhaustive of, or limiting of, the spirit hereof.

The precise constructions of the figures of the drawings need not be slavishly followed as, of course, various components may have to be modified in accordance with any specific adaptation to which it is to be put. Stated otherwise, the objects are susceptible of attainment by use of constructions differing in certain respects from those dis-closed, all without departing from the underlying principles hereof.

The advantages hereof are best realized when all of its features and instrumentalities are combined unitarily,

but useful embodiments may be produced involving less than the whole and it will be borne in mind, in the reading hereof, that all of the recited components need not necessarily be present in a single construction in order to satisfy the spirit and scope hereof.

The novel features characteristic of my invention, as to its principles of design and operation, and as to its construction and organization, will be best understood from a consideration of the following detailed description when read in conjunction with the drawings in which:

FIG. 1 is a view in top plan of an economy style of tray or carton type blank whereon are delineated the areas or portions thereof where the moisture content is purposely augmented preliminary to the carton-erecting program;

FIG. 2 is a view in top plan of a conventional style of tray or carton type blank Whereon are delineated the areas or portions thereof where the moisture content is purposely augmented preliminary to the carton-erecting program;

FIG. 3 is a view in top plan showing the economy style blank of FIG. 1 in solid lines superimposed upon the conventional style blank of FIG. 2 in phantom lines;

FIGS. 4-8 are views in end elevation, illustrating somewhat diagrammatically and in a progressive series, the sequential steps in the moisturizing and the folding of the bottom panel glue tabs, front and rear and end panels, and rear panel glue tabs of an economy style blank in the program of carton erection;

FIG. 9 is a fragmentary view in rear elevation of the partially-erected carton of FIG. 7;

FIG. 10 is a fragmentary view in front section of certain components of the prefolding mechanisms and of certain blank and liner guide and locating member-s showing a tray blank and cooperant liner in registered positions before initiation of the erecting cycle and further showing the blank moisturizing means;

FIG. 11 is a fragmentary view in side elevation of the components of FIG. 10 with the blank and liner having been carried forwardly from their station of registration by the mandrel and into their respective pre-folded positions and further showing blank moisturizing means;

FIG. 11A is a fragmentary View in side elevation showing the steam vent grooves in a wall of the mandrel;

FIG. 11B is a fragmentary view in end elevation showing the steam vent grooves in the wall of the mandrel;

FIG. 12 is a View in top plan of the erecting assemblage of the invention;

FIG. 13 is a view in side elevation showing a fully erected tray and integrated liner, the mandrel and erecting assemblage being shown at the inward extremity of the folding and sealing cycle;

FIG. 14 is a partial view in end elevation, taken from the left of FIG. 13, with portions of the mandrel and tray blank and liner guides being broken away for purposes of clarity;

FIG. 15 is a view in section on the line 15-15 of FIG. 13;

FIG. 16 is a fragmentary view of a tray and liner and a folding and sealing plate modified to include a spring means for pressing the liner into heat-sealing position;

FIG. 17 illustrates, in perspective view, an economy style blank inclusive of bottom panel glue tabs, in erected position as a tray;

FIG. 18 illustrates, in perspective View, an economy style blank absent bottom panel glue tabs, in erected position as a tray;

FIG. 19 illustrates, in perspective view, an economy style blank inclusive of bottom panel glue tabs, in erected position as a carton with hinged cover;

FIG. 20 illustrates, in perspective view, an economy style blank with cooperant liner, in erected position as a tray;

FIG. 21 illustrates, in perspective view, an economy style blank inclusive of bottom panel glue tabs and with cooperant liner, in erected position as a tray, with portions of the blank being broken away for purposes of clarity; and

FIG. 22 illustrates, in perspective view, an economy style blank absent bottom panel glue tabs but with cooperant liner, in erected position as a tray, with portions of the blank being broken away for purposes of clarity.

In the following detailed description and appended claim, various components and details thereof are identified by specific names and terms for convenience, although such are intended to be as generic in their application as the art will permit.

With continued reference now to the drawings, I have provided figures, in greatly simplified form and with some in semi-diagrammatic form, showing the essentials of the invention as advantageously incorporated within the rudiments of a specific apparatus, all in order that the general relationship and coaction of components may be better understood.

It is to be understood that the apparatus may be modified to suit individual and/or specific operating requirements. For instance, while I have shown a horizontallyreciprocating forming mandrel or prime mover, it will be evident that the apparatus can be suitably operated as by a vertically or angularly-reciprocating prime mover, through appropriate modification. v

I have not shown herein a means for actuating or motivating the prime mover, it being comprehended that same could be caused to operate under the influence of any suitable motivating means. Nor have I shown a means for feeding the blanks and/ or liners relative to the erecting assemblage, it being explained that, conceivably, feeding could be accomplished manually or by means of feed hoppers or the equivalent for holding a supply of blanks or by means of web rolls or equivalent from which sections forming liner blanks may be severed. These feeding devices may be of any of the known styles for delivering the blanks and liners, simultaneously or in seriatim, into proper registration with each other preliminary to erection. Nor have I shown herein a means for removing an erected-carton from the mandrel, it being understood that such discharge may be suitably accomplished by hand or mechanical means.

The economy style carton blank comprehended herein may be formed of any foldable material, although preferentially, it is formed of paperboard, and will carry overall or spot coatings of a heat-scalable medium on certain surfaces or portions of surfaces of certain of its panels, which will be subjected to heating and pressure sealing during certain of the sequential steps in the carton-erecting operation whereby the erected end product is fully sealed in certain contacting and permanently-bonded areas or portions thereof.

The liners comprehended for use herein may be formed of any sheeting of a suitable film, paper or foil or laminated combinations thereof, and preferably will have an overall heat scalable coating on one surface thereof for sealing contact with the adjacent surfaces of the blank.

In FIG. 1, I have shown an economy style tray or carton type blank, generally indicated by numeral 10, which is die cut and prescored, its component elements comprising a bottom panel 12, front and rear panels 14 and 16 respectfully which are hingedly connected to the bottom panel at opposite side edges thereof along score or folding lines 18 and 20 respectively, with an end panel 22 at each opposite end edge of the front panel which is hingedly connected thereto along the respective score line 24, 26, with a dust flap 28 at the upper edge of each end panel which is hingedly connected thereto along the respective score line 30, with a bottom panel glue tab 32 at each end edge of the bottom panel which is hingedly connected thereto along the respective score line 34, and with a rear panel glue tab 36 at each end edge of the rear panel which is hingedly connected thereto along the respective score line 38.

Bottom panel glue tabs-32 are each provided with one end edge 40 which is angularly-disposed relative to the longitudinal axis defined by score line 20, the angle being delineated by the letter A, and rear panel glue tabs 36 are each provided with one end edge 42 which is angularlydisposed relative to said longitudinal axis, the angle being delineated by the letter B, angle A being equal to or greater than angle B and preferentially, the sum of the angles A and B, represented by the letter C, being 90, or slightly greater than 90, for reasons to appear.

The score or folding crease lines are indicated by broken lines in flat representation and in full lines in folded or partially-folded representation, except in the case of cut score 26, which is a part of score line 24 between front panel 14- and each end panel 22. All other score lines may be crease or cut scores or combinations thereof to suit the requirements of a specific container or of a specific type of material.

In the design of a blank of such a configuration that a slit 43 is provided so as not to require the removal of stock between end panel 22 and glue tab 32, it is imperative that score 26 which is a portion of score line 24 constitute a cut score so as to permit the formation of a square tray or carton. A cut score serves to eliminate the usual interference resulting from a crease score. Such cut score 26 should be of length equal to or greater than the width of the adjacent glue tab 32. Conceivably the cut score may be provided throughout the full length of each front panel-end panel interconnection.

Bottom panel glue tabs 32 and rear panel glue tabs 36 may be provided, on their respective outer surfaces, with a coating of a heat scalable medium 44, according to any desired glue pattern. Reversely, such coating may be provided on the inner surfaces of end panels 22. It is not necessary that both of the confrontable surfaces be so conditioned in order to effectuate successful heat sealing of one member to the other.

Such coating may be in the form of an overall coating on the selected panels or glue tabs or in the form of spaced, strategically-located spots.

If otherwise desired, in preference to preconditioning the blanks with a heat sealing medium, such medium conceivably could be applied to the appropriate surfaces of the panels and/ or glue tabs in situ at the carton-erecting station or adjacent thereto by way of suitable instrumentation associated with the means supporting the erecting components.

Additionally, in FIG. 1, I have delineated, by means of dash lines, areas a, a at opposite ends of the blank and an area b intermediate said areas a, a. It will be understood that the portions of the blank appearing within the bounds of each a area will be the portions of the blank, the moisture content of which will be purposely increased or augmented by the application thereto of a film of water on one or the other or both of the sides of the blank.

I have shown, in FIG 2, a conventional style tray or carton type blank, generally indicated by numeral Stl, and comprising a bottom panel 52 and front and rear panels 54 and 56 respectively which are hingedly connected to said bottom panel at opposite side edges thereof along score lines 58 and 60 respectively. Additionally, at each opposite end edge of said front panel, a front panel glue tab 62 is hingedly connected thereto along the respective score line 64, and at each end edge of said bottom panel, an end panel 66 is hingedly connected thereto along the respective score line 68, Still further, at the opposite end edge of each said end panel, a dust flap '70 is hingedly connected thereto along the respective score line 72;, and ateachend edge of said rear panel, a rear panel glue tab 74- is hingedly connected thereto along the respective score line 76.

Attention is directed to the usual removal of segments of stock between end panels 66 and respective adjacent glue tabs 62and 74, the necessity for which is obviated in the case of the economy style blank carton.

Additionally, I have delineated, by means of dash lines, areas c, c at opposite ends of the blank and an area d intermediate said areas 0, c. It will be understood that the portions of the blank appearing within the bounds of the dash lines and Within the bounds of each c area will be the portions of the blank, the moisture content of which will be purposely increased or augmented by the application of a film of water on one or the other or both of the sides of the blank.

With conjoint reference to FIGS. 1 and 2, I have shown in FIG. 3 an economy style tray or carton type blank 10 in superposed relation upon a conventional style tray or carton type blank 5!), to dramatize the markedly appreciable savings of material, in the range of 15 to 25%, realizable with the economy style blank. Whereas the blanks under. comparison are shown as allowing containers of identical size, the overall length of the economy style blank will be observed to be shorter than the conventional style blank. It will also be apparent that an economy style blank may be identified as one wherein the depth, or height, inclusive of the dust flaps, exceeds the width of the erected-carton. Such is possible when the width of the carton, whether of tray or carton type, is less than the overall height of an end panel thereof.

In FIGS. 48, I have shown the successive or sequential stages or steps in the erection of a die cut and prescored economy style blank into a tray type carton or container according to the teaching of the invention, in an effort first to illustrate these stages with reference to a carton blank alone and free of instrumentation.

It will be understood that the erection of a blank of the carton or tray type incorporating an integrallyattached cover member comprises essentially the same sequence of steps.

It will also be, understood that, while the erecting procedures are explained hereinafter with specific reference to the economy style blank 10, the procedures could apply with equal force to the blank 50 or any other type of carton blank used in a heat sealing operation.

Further, while no cooperant liner is shown, it will also be understood that substantially the same sequence of steps obtains when a blank and liner are erected.

As illustrated, blank 1% will be considered to be fed vertically downwardly into registering position'from above in the direction of arrow D.

Preliminary to delivery to the registering position and at some selected position, blank 10 will be subjected to a moisturizing treatment so thatareas a, a of the blank will become wetted as by a spray of water, with or without a wetting agent additive. Such application may be accomplished by means of a pair of applicators 131 in the form of spray nozzles, roller applicators, wick type applicators or other suitable moisture applying means. strategically positioned relative to the path of travel of the blank so that one or both of the sides of all surfaces within the areas a, a will be so treated as it moves therepast on its way to registry position. 'Moisturizing will take place in the timed relation to the movement of the areas a, a past the applicators 131.

Alternately, and as above alluded to, the blanks may be properly conditioned by the storage of same within a controlled atmosphere of approximately 68% relative humidity for approximately 48-72 hours preliminary to use, wherefor the moisture applying means may be dispensed with.

With further reference to FIG. 4, the blank is observed to be moisturized by the applicators 131 on either or both sides thereof preliminary to being positioned into a predetermined location Where it will be in register with a mandrel which, in operation, will reciprocate along a horizontal axis denoted by the phantom line E, firstly, in a left-to-right direction as denoted by arrow G, and secondly, reversely in a right-to-left direction as denoted by arrow F. Alternately, the blank could be initially fed horizontally sidewise to a position of proper registration with a vertically-reciprocating mandrel.

In the first stage of the progression of sequential steps, represented by the showing of FIG. 4, blank 10 will be understood to be in proper register with the cooperant instrumentalities.

In the second stage of the progression, represented by the showing of FIG. 5, bottom panel glue tabs 32 are preliminarily folded to assume planes approximately at 90 angles relative to the plane of bottom panel 12 along respective score lines 34.

In cases where a blank and liner are erected conjointly, it is necessary to prefold the front and rear panels 14 and 16 respectively, as shown in phantom in FIG. 5, for efiecting a control of the liner end folds and this is so whether or not the blank is of normal type incorporating bottom panel glue tabs or is of the type which may not necessitate same.

In the third stage of the progression, represented by the showing of FIG. 6, the aforedescribed initial folding is followed by the allowance of bottom panel glue tabs 32to spring back so as to assume the somewhat angular positions shown. With bottom panel glue tabs 32 hav ing so sprung backwardly, front and rear panels 14 and 16 respectively and end panels 22 and rear panel glue tabs 36 and bottom panel glue tabs 32 are partially fold-ed, with the folding of front panel 14 preceding the folding of rear panel 16 in point of time.

In the fourth stage of the progression, represented by the showing of FIG. 7, front panel 14 is observed to have been fully folded or erected to a position where it is disposed in a plane at substantially 90 relative to the plane of bottom panel 12 and end panels 22 and bottom panel glue tabs 32 are observed to have been almost completely folded, and rear panel 16 and rear panel glue tabs 36 are observed to have been partially folded.

conceivably, front panel 14 could be disposed in a plane greater than 90 to the plane of bottom panel 12 to suit certain conditions as may be required for a container with tapered sides.

In the sequence of steps, rear panel 16 and rear panel glue tabs 36 are desirably not folded beyond the position illustrated in FIG. 7 until the other panels are in their illustrated positions, all to insure a proper deflection of rear panel glue tabs 36 inwardly of their respective end panels 22. The confronting relationship of panels and glue tabs is best illustrated in the supplemental showing of FIG. 9 wherein rear panel glue tabs 36 and bottom panel glue tabs 32 are shown to be folded and rotated into their finally-erected positions before the respective end panels 22 assume their final positions relative thereto.

In the fifth and final stage of the progression, represented by the showing of FIG. 8, the fully-erected carton condition is illustrated.

The sequential steps of folding the blank may be summarized as: first, moisturizing the blank; second, prefolding the bottom panel glue tabs; third, deflecting the front panel; fourth, allowing the bottom panel glue tabs to spring backwardly during front panel deflection for the retaining engagement of each bottom panel glue tab behind its respective end panel; fifth, folding the end panels and bottom panel glue tabs and rear panel glue tabs simultaneously while the front panel is rotated into completely formed position and while the rear panel and associated rear panel glue tabs are partially rotated with the rear panel glue tabs being deflected inwardly of the adjacent end panels; sixth, completing the rotation of the rear panel and its associated glue tabs; seventh, bringing the end panels and associated bottom and rear panel glue is tabs into sealing engagement; and eighth, venting the accumulated steam from areas of the end panels.

Where a blank and liner are formed simultaneously, the sequential steps may be summarized as: first, moisturizing the blank; second, prefolding the bottom panel glue tabs and the cooperant portions of the liner and simultaneously deflecting the front and rear panels and the cooperant portions of the liner; third, allowing the bottom panel glue tabs to spring backwardly for the retaining engagement of each bottom panel glue tab behind its respective end panel; fourth, simultaneously folding the end panels and bottom panel glue tabs and the rear panel glue tabs and the cooperant portions of the liner while the front panel and cooperant portions of the liner are rotated into completely formed position and while the rear panel and the associated rear panel glue tabs and the cooperant portion of the liner are partially rotated with the rear panel g-lue tabs being deflected inwardly of the adjacent end panels; fifth, completing the rotation of the rear panel and its associated glue tabs and the cooperant portions of the liner; sixth, bringing the end panels and associated bottom and rear panel glue tabs and cooperant liner into overlapping and sealing engagement; and seventh, venting the accumulated steam from areas of the end panels.

Conceivably a blankcould be employed which did not employ bottom panel glue tabs. In such instance, the sequential steps would comprise; first, moisturizing the blank; second, folding the end panels and rear panel glue tabs simultaneously while the front panel is rotated into completely formed position and while the rear panel and associated rear panel glue tabs are partially rotated, with the rear panel glue tabs being deflected inwardly of the adjacent end panels; third, completing the rotation of the rear panel and its associated glue tabs; fourth, bringing the end panels and the rear panel glue tabs into sealing engagement; and fifth, venting the accumulated steam from areas of the end panels.

Where such a blank, absent bottom panel glue tabs, is employed and where a liner is simultaneously formed therewith, the sequential steps may be observed to include: first, moisturizing the blank; second, simultaneously deflecting the front and rear panels and the cooperant portions of the liner and the prefolding of portions of the liner extending outwardly of the opposite ends of the bottom panel; third, simultaneously folding the end panels and the rear panel glue tabs and the cooperant portions of the liner while the front panel and cooperant portions of the liner are rotated into completely formed position and while the rear panel and the associated rear panel glue tabs and the cooperant portion of the liner are partially rotated with the rear panel glue tabs being deflected inwardly of the adjacent end panels completing the rotation of the rear panel and its associated glue tabs and the cooperant portions of the liner; fourth, bringing end panels and rear panel glue tabs and cooperant liner into overlapping and sealing engagement; and fifth,

venting the accumulated steam from areas of the end panels.

Reference will now be made to the registration and prefolding components, as shown in FIGS. 10 and 11. For purposes of simplification, the framework of a supporting apparatus which aids in the positioning of these registration and prefolding components relatively to each other is not shown. Any suitable conventional framework may be adapted for such support function and does not constitute a part of this invention. Likevw'se, the components which support and supply reciprocating movement to a mandrel 10%) and the feeding mechanism which delivers the blank from a stack or magazine or equivalent supply means and a cooperant liner, if one be used, from a stack or roll or equivalent supply means, to the registration point or station are not shown, and again for the reason that same do not constitute parts of this invention.

With reference to FIG. 10, a blank and liner L will be understood to have been delivered simultaneously, or in seriatim, to their respective positions of registry in substantial face-to-face relationship with each other at the socalled registration station.

ln moving to said station, the blank is caused to move past the pair of strategically-positioned spray nozzles 131 for purposes of moisturizing areas a, a of the blank. Such spray means may be disposed at opposite sides of the path of travel of the blank, if moisturizing of both surfaces of the areas a, a is desired.

The outer edge portions of end panels 22 of the blank are each receivable within the adjacent inwardly-facing vertically-disposed registration slot 102 provided in a vertically-disposed blank guide 106 at each side of the registration station. The blank guides are arranged in spaced parallelism as to each other and are each provided with an inwardly-facing vertically-disposed registration slot 1&2. Being spaced, they allow sliding accommodation therebetween of a blank in manner whereby the outer edge portions of the blank end panels 22 are slidably receivable within the respective registration slot 102.

Blank guides 1&6 may be adjustably positioned relative to suitable frame members of the support means whereby they may be variably positioned so as to serve blanks of different dimensions.

Rearwardly of each blank guide 106 and adjustably secured thereto by suitable means, not shown, is a vertically-disposed liner guide 104 to allow a pair of such liner guides strategically located in spaced parallel relationship as to each other on opposite sides of the registration station and in a vertical plane immediately and rearwar-dly adjacent the vertical plane of blank guides 196. Said liner guides project inwardly toward the center of the registration station and extend inwardly beyond the vertical plane defined by the registration slot 102 of their respective blank guides. Being adjustable, the positioning of liner guides Hi4- relatively to blank guides 106 may be varied to the accommodation of blanks and liners of varying dimensions.

With a blank being receivable within the registration slots of the blank guides, sufficient clearance is allowed for the reception therebehind of a liner so that the opposite side edge portions of the liner will be supported by and forwardly of the respective liner guides.

Within and at the lower portion of each registration slot W2, an insert 108 is removably receivable. Each insert is provided with an upper inwardly-inclined surface 110 and an inner vertically-disposed surface 112, which surfaces are disposed in pairs on opposite sides of the registration station and serve conjointly to center the lineras same is moved vertically into registering position. Said inserts may be adjusted in their positions relative to the respective slots, or may be replaced with inserts of other configurations but of identical purpose, so as to accommodate blanks and liners of different dimensions.

Forwardly of and adjacent the lower extremities of liner guides 104 and vertically beneath the lower extremities of blank guides 1%, a pair of coaxially-disposed liner stops Eldare adjustably secured to said liner and blank guides by suitable means in manner to close the lower open end of the respective registration slot 102 and to allow aligned upper surfaces 116 which the lowermost edge of liner L will abut, as it assumes its registering position.

Liner stops 114 may be vertically adjusted relative to liner guides N4 and blank guides 106 so as to vary the positioning of the accommodated liners L, all whereby liners of varying dimensions may be served.

Strategically located within each registration slot 162, a blank stop 118 is adjustably secured by suitable means. The blank stops of the pair thereof are horizontally aligned as to each other to allow a limit shoulder at each side of the registration station against which the edge of one of the blank end panels 2?. abuts as the blank assumes registering position.

Adjustably secured to each liner stop 114, by suitable means in manner to project upwardly and forwardly thereof, is an inclined rear panel and liner guide and prefolder 122 which may be adjusted relative to said liner stops to accommodate blanks and liners of varying sizes.

Said rear panel and liner guides and prefolders function operationally to initiate guiding and prefolding of rear panel 16 of the blank, and the liner when and where used, delivered to the registering station and in the process of being pushed forwardly therefrom by mandrel 100.

For simultaneously erecting a blank and liner, there will be additionally provided a pair of adjustable horizontally-spaced, parallel, fingerlike front panel and liner prefolders 126, which project downwardly from the frame of the apparatus in a vertical plane immediately forwardly of the vertical plane defined by a registered-in-position blank and liner. They function operationally to initiate prefolding of the blank front panel 14 and the liner delivered to the registering station, as they are pushed forwardly therefrom by mandrel flit. Said front panel and liner prefolders may be adjustably positioned relative to the registration station to accommodate blanks and liners of varying dimensions.

On the outwardly facing side thereof of each blank guide 1% an inwardly and forwardly inclined bottom panel glue tab folder 128 is adjustably secured by any suitable means, they being horizontally aligned as to each other, and extending generally inwardly toward each other inwardly of the vertical plane defined by its respective blank guide a distance sufiicient to assure confrontation with the respective bottom panel glue tab and the deflection thereof as mandrel ltltl moves forwardly through the registration station to drive the blank, or the blank and liner, therewith.

The registration station is defined as being that area bounded by the pairs of liner and blank guides, the pair of liner stops and the associated pair of rear panel and liner guides and prefolders, the pair of front panel and liner prefolders, and the pair of bottom panel glue tab folders. Through said registration station, the mandrel 109 is movable transversely relatively thereto in a forward carton-erecting direction from a position rearwardly of the registration station to a position forwardly thereof and also to be movable reversely in a retrograde carton-sealing-and-pressurizing and erected-carton-ejection direction.

As the forward face of mandrel 106 projects through the registration station, bottom panel 12 of the blank, and the adjacent portion of the liner if one is used, are in registration with the bottom face of the mandrel so as to be projected forwardly therewith, asshown in FIG. 11, with bottom panel glue tab folders 12% serving to deflect the respective bottom panel glue tabs 32 and adjacent liner portions rearwardly, and with front panel and liner prefolders 126 serving to deflect the front panel 14 and adjacent liner portions rearwardly, and with rear panel and liner guides and prefolders 122 serving to deflect the rear anel and adjacent liner. portion rearwardly, the simultaneous prefolding features thus represented being essential properly to control the initiation of the liner folds, particularly in the corner areas at the opposite ends of the liner.

The blank and liner will be observed, in FIG. 11, to be located not only at the so-called prefolding station of the carton-erection program but also at the, station where the bottom panel of the blank is in configuration with a blank retainer plate 32%, subsequently to be described, which blank retainer plate is projected into blank retaining position outwardly of the plane of a bottom panel plate 310, said blank retainer plate serving to'hold the blank and liner in positions of register as to each other and as to the bottom face of the mandrel as said mandrel moves the blank and liner past prefolders 12-2, 126' and 128 and into engagement with the folding and sealing components.

Said blank retainer plate 320 will be spring-loaded with respect to a slide shaft 220 supporting the bottom plate 310 by a spring means 328.

The blank and liner having so been driven forwardly, bottom panel 12 of the blank first confronts the erecting, or forming and sealing, assemblage aligned with the mandrel and disposed forwardly thereof, which erecting, or folding and sealing, assemblage is stationarily or rigidly fixed to the same supporting construction accommodating the registering and prefolding instrumentation and comprises a plurality of stationary or fixed components which, during operational use, remain in fixed positions relative to the assemblage and supporting structure and a plurality of movable components which, during operational use, move cooperantly according to the dictates of mandrel 199 in a forward, carton-erecting direction and of an air cylinder or equivalent spring return means (to be described) in a rearward or retrograde movement.

The stationary or rigidly fixed components of the assemblage are described as constituting a pair of spaced horizontally-extending cross-braces 260 held in separated parallel relationship as to each other by a suitably configured spacer 202 disposed therebetween and secured thereto as by a bolt 204 and nut (not shown) adjacent each end section of the interrelated cross-braces, and a pair of spaced vertically-extending posts 210 similarly held in separated parallel relationship as to each other by other spacers (not shown) and disposed therebetween and secured thereto. The employment of such spacers allows the adjustable spacing of the cross-braces as to each other and the adjustable spacing of the posts as to each other. Said cross-braces and posts are arranged in crossing right angular relationship as to each other, with the cross-braces disposed in a vertical plane forwardly of the vertical plane of the posts, as viewed in FIG. 13, and the pair of crossbraces and the pair of posts being secured to each other as by pairs of gibs, one forward pair of suitably notched gibs 212 being secured to the forwardly-facing faces of the cross-braces as by bolts 214 and one rearward pair of suitably-notched gibs 216 being secured to the rearwardlyfacing faces of the posts as by bolts 218, said gibs cooperating for holding in place a horizontally-arranged slide shaft 22% as adjusting or take-up shoes functioning to allow a proper sliding fit therebetween and taking-up for wear through continued service.

Slide shaft 22% is provided along its length with a square portion 221, and a relieved cylindrical portion 223. During the folding portion of the cycle, square portion 221 is accurately guided in the sets of notched gibs 212 and 216 for maintaining proper component registration. During the sealing portion of the cycle, cylindrical portion 223 enters the first set of gibs to allow the entire assembly to float Within certain predetermined limits, thereby to pro vide a self-aligning feature for aiding in the equalizing of heat sealing pressure.

With references to FIG. 12, the rearmost end of slide shaft 220 is suitably threaded to receive the forwardmost end of a horizontally-disposed coaxially-aligned piston rod 236 extending forwardly from a rearmost-located air cylinder 232, which air cylinder is provided with suitable air connections 234 for appropriate connection to a source of air supply (not shown) in known manner. The air cylinder may be suitably supported in a generally horizontally-disposed position as by a vertically-disposed end plate 236 which the air cylinder embraces and through a central opening of which the piston rod and securing means on the end face ofthe air cylinder extends. The securing means is adapted to be threadedly engaged as by a nut 238 wherewith the air cylinder is clamped to the end plate. A pair of spaced air cylinder support brackets 240 have rearmost end portions which are interengageable with said end plate as by bolts 242 and nuts 244 and have forwardmost end portions which are interengageable each with a side face of one of the posts as by bolts 246, to the end that the air cylinder is supported relative to the rest of the erecting assemblage.

A front panel actuating roll arm support bracket 25%), disposed in horizontal alignment with and vertically above slide shaft 220, is fixedly secured to posts 210 of the pair thereof as by forward and rearward bracket clamp plates 252 and 254 respectively which are disposed against the forward and rearward faces of the posts respectively, with bracket 25h being clamped between the forward clamp plate and forward faces of the posts as by bolts 256. Similarly, a rear panel actuating roll arm support bracket 260, disposed in horizontal alignment with and vertically below slide shaft 220, is fixedly secured to the posts of the pair thereof as by other forward and rearward bracket clamp plates 262 and 264 respectively which are disposed adjacent the forward and rearward faces of the posts respectively, with bracket 260 being clamped between the forward clamp plate and forward faces of the posts as by bolts 266.

Vertical adjustment of brackets 250 and 260 relatively to the posts is allowed by a loosening of bolts 256 and 266 respectively, a manual movement of the brackets, and a retightening of the bolts when the brackets have assumed desired readjusted positions.

Brackets 250 and 260 are suitably slotted at 268. A front panel actuating roll arm 270 and a rear panel actuating roll arm 280 are each slidably engaged with the respective bracket as by a bolt 272 extendable through the slot of the bracket and threadedly engageable in the respective actuating roll arm. The front and rear panel actuating roll arms are each forwardly and rearwardly movable relative to their respective brackets by a loosening of bolt-272, a desired adjustment movement of the actuating roll arm relative to the bracket, and a retightening of the bolt.

Transversely-arranged front panel and rear panel actuating rolls 274 and 284 respectively are suitably journalled in the forward ends of front and rear panel actuating roll arms 270 and 280 respectively.

In operation, front panel actuating roll 274 will be desirably disposed in a vertical plane forwardly of the vertical plane of rear panel actuating roll 284-.

At each side of slide shaft 220, an end panel folding and sealing bracket 290 is adjustably secured to the forward faces of the pair of cross braces 200 as by a bolt 292 extendable through an apertured plate 294 and through the space allowed between the cross braces and threadedly engageable with a foot portion of the respective said folding and sealing bracket.

Each said end panel folding and sealing bracket will be suitably bifurcated or otherwise configured to allow reception therethrough of an end panel folding and sealing arm 296 pivotally mounted relatively to its respective bracket as by a pin 298, said arm having a transversely-arranged end panel folding and sealing roll 300 suitably journalled in its forward end and having a transversely-extending spring-loaded bolt 302 threadedly engaged therewith at its rearward end serving to urge the rearward end of the arm away from the longitudinal axis defined by slide shaft 220 and to bear against an adjustable stop means 304 threadedly secured to the respective end panel folding and sealing bracket, all whereby the forward end of the arm is urged toward the longitudinal axis of slide shaft 226.

The blank retainer plate 320 of the bottom plate subassembly is interconnected to and guided relative to bottom plate 310 by means of a blank retainer plate support pin 322 centrally located relative to the rearwardly-facing face of the blank retainer plate and having an outer end fixedly secured thereto by appropriate means. The said pin is of such length as to allow its opposite end portion to be receivable within a suitable longitudinal bore extending through said slide shaft and to be retained therewithin by means of an enlarged head 324 at the said opposite end of said pin, which head abuts against an in- 15 wardly-extending radially-arranged slide shaft limiting shoulder 326 wherewith the forwardmost positioning of the blank retainer plate relative to the bottom plate is predetermined.

The spring-loading feature of said blank retainer plate is provided by a spring means 328 sleeved within the slide shaft bore and having a forwardmost end bearable against pin head 324.

A blank retainer plate guide pin 33f) transversely-spaced from pin 322 is secured at the forward end to the rear face of said blank retainer plate and is of such length that its rearward end is extendable through an opening extending through said bottom plate, whether the blank retainer plate be in its normal forwardly-extended position of rest spaced from the bottom plate or in its rearwardly-extended position of compression for operating whereat it is flush with the face of the bottom plate, wherewith the blank retainer plate is guided and squared relatively to the bottom plate. Said normal or rest blank retainer plate position, forwardly of the bottom plate by virtue of said spring loading is shown in FIG. 11.

An end panel folding and sealing plate 346 is pivotally connected to bottom plate 310 at each end thereof as by a pivot pin 342. Means may be provided for adjusting the positioning of said pivot pins transversely relative to the bottom plate for adjusting the location of the end panel folding and sealing plates relative to the bottom plate, all whereby blanks of different dimensions may be accommodated by the same assemblage.

The opposed end panel folding and sealing plates 34% are interconnected by means of a pair of springs 344 extendable therebetween astride and on opposite sides of slide shaft 220, each spring being engageable at its opposite extremities with an adjacent spring stud 346 projecting outwardly from its respective end panel folding and sealing plate 349, Wherewith the end panel folding and sealing plates are urged into normally open rest position where they are disposed in planes slightly angular relative to the plane of the face of bottom plate 310. When the end panel folding and sealing plates are actuated into operating position, springs 344 are loaded so as to urge the plates to return to their normal open rest positions upon relief from their operative functions.

A cam member 350 is fixed to the rearward face of each end panel folding and sealing plate as by bolts 352 and is provided with a cam face 354 and a pressure dwell 356. The adjacent pressure roll 390 is operationally adapted to be rollable along said cam face to provide the requisite dwell time during the sealing phases of the carton erecting and retrograde travel of the mandrel and the bottom plate subassembly and the end panel folding and sealing plates travelling therewith.

Bottom panel and rear panel glue tab deflector plates 341 may be fixed to the forward faces of each of the end panel folding and sealing plates and may comprise a step or offset serving in point of time to be brought into confrontation with the respective said glue tabs before the respective end panels are brought into confrontation therewith. Alternatively, instead of deflector plates being stat-ionarily secured, offsets could be machined into the forward faces.

In FIG. 13, I have illustrated a rear panel glue tab 36, in phantom, out of folding sequence, merely to show same as resting against a deflector plate 341.

Cartridge heaters 358 or electrodes for dielectric sealing or equivalent conventional heating means (not shown) are disposed in appropriate cavities or recesses within each end panel folding and sealing plate and within the mandrel, with appropriate energization and control means being associated therewith. Here again same are not shown for purposes of simplification.

A front panel folding plate 360 is secured to the face of a roller engaging member 364 which is pivotally engaged as by a pivot 352 to bottom plate 310. On the outer surface of the member 364, the adjacent actuating roll 274 is operationally adapted to be reliable along the rearward face thereof to provide the requisite front panel folding action during carton-erecting travel of the bottom plate subassembly and the' front panel folding plate travelling therewith.

A rear panel folding plate 379 is secured to the face of a roller engaging member 3'74 which is pivotally engaged as by a pivot 372 to bottom plate 3&0. On the outer surface of member 364, the adjacent actuating roll 284- is operationally adapted to be rollable along the rearward face thereof to provide the requisite rear panel folding action during carton-erecting travel of the bottom plate subassembly and the rear panel folding plate travelling therewith.

Torsion springs 37%, provided for returning the front and rear folding plates to normal rest positions, are sleeved upon the respective pins 352 and 372 between bottom plate 31d and a suitably positioned collar 379.

T he apparatus of the invention is such as to allow the performance of all of the prefolding and folding and sealing operations in a series of sequential steps in a single cyclic movement.

The initial stage of the operation comprehends the registering at the registration station of the blank relative to the mandrel, or, where a liner is used therewith, the registering of the blank and liner relative to each other and to the mandrel. So registered, the mandrel is actuated in its carton-erecting direction so as to embrace, with its bottom face, the carton bottom panel, or the portion of the liner adjacent the carton bottom panel where a liner is employed, and to urge the blank, or the blank and liner, toward the blank retainer plate, with the end panel glue tabs and the front and rear panels being deflected from their coplanar relationship with the bottom panel as the bottom panel is clamped between the mandrel face and the opposed face of the blank retaining plate.

The end panel and glue tabfoldi-ng and sealing plates and the front and rear panel folding plates are strategically positioned to each other so as to allow such actuation thereof in point of time that the front panel folding plate first achieves a full folding of front panel 14 (i.e. a fold of between front panel 14 and bottom panel 12) while each end panel folding and healing plate has achieved an almost complete folding of its associated end panel 2-2 and bottom panel glue tab 32 and rear panel glue tab 36, and rear panel glue tab deflector plates 341 having deflected their respective glue tabs forward of end panels 22, while the rear panel folding plate has achieved only a partial folding of rear panel 16.

Continued carton-erecting motion of the mandrel next assures full folding of the rear panel folding plate and consequent erection of the respective rear panel and rear panel glue tabs therewith, with the end panel and glue tab folding plates continuing their respective movements to bring the end panels and glue tabs into sealing position.

In FIG. 13, mandrel 109 and the erecting assemblage will be observed to be positioned at the inward end of the carton-erecting direction of movement. Rollers 274 and 284 have urged front and rear panel folding plates 366) and 37th into fully erected position. Simultaneously, rollers 300 have urged their associated end panel folding and sealing plates 346 into fully erected position, all to the end that an erected tray or container is formed.

The preheating time of the end panels and glue tabs of the blank, and the overlapping end folds of the liner, when used, is represented as the total time during which the end panels and glue tabs are sufficiently close to the end panel folding and sealing plates as to be heated thereby. The heat seal-ing time of the end panels and glue tabs and the overlapping folds of the liner is represented as the total time during which the end panels and glue tabs and overlapping folds of the liner are subjected to the pressure of the end panel folding and sealing plates by their respective pressure rolls in carnrned relationship with the cam mem- 17 hers thereof during the sealing portion of the cartonerecting travel of the mandrel and during the sealing portion of the retrograde travel thereof.

The opposite end faces of mandrel 100 are relieved as at 101 to define an area adjacent the canton sealing area for purposes of compensating for the double thickness of the paperboard resulting from the overlapping of an end panel and glue tab. Such relief allows uniform overall contact of the folding and sealing plates with the outer surfaces of the end panels. A single thickness area of each end panel is subject to heat and pressure during the heat seal-ing portion of a cycle. Under certain conditions of machine speed, temperature, pressure, and moisture content, steam will form internally in this area to cause the paperboard to delaminate and form blisters. To prevent such, steam vent grooves 103 are machined into this area of both ends of the mandrel. These grooves may vary in width and depth to suit the thickness of paperboard being employed. Likewise the number of grooves required may vary with respect to the size of the carton.

As an additional feature, the outermost face of blank retainer plate may be faced by a lining 321 of soft, resilient material, such as sponge rubber or the like, and the confronting bottom face of the mandrel may be relieved for accommodating of the said face of said blank retainer plate.

By the coaction of the so-constituted blank retainer plate and bottom face of the mandrel, bottom panel 12 of the blank will be observed to be deformed inwardly, under pressure so as to overbreak along score lines 18, 20 and 34 beyond 90 wherefore a more-squarely formed carton results.

The slide shaft will be observed to be provided with a relieved portion 223 for the purpose of allowing a floating feature during the sealing part of the cycle where the relieved portion of the slide shaft enters the first set of gibsto allow the entire movable assembly to float a controlled amount and to be self-aligning wherewith the heat sealing pressure is equalized.

By the heat sealing means, the interengagement of the outer face of each glue tab and a portion of the inner face of the related end panel is realized.

When the forming mandrel is released and withdrawn outwardly, the now erected carton travels with the mandrel until acted upon by suitably positioned stripper fingers (not shown).

The apparatus hereof does not push the formed carton through the forming section, in contradistinction from most prior art devices, but rather returns it to a point distantly of the forming section for discharge therefrom, all to the end that the length of the stroke required for the mandrel is appreciably reduced, a feature especially advantageous in the case of formed cartons incorporating hinged covers.

The retrograde movement of the mandrel allows the concomitant movement of the slide shaft by the air cylinder so as to lead to the return, to normal rest positions, of the bottom panel plate and of the end folding and sealing plates, and of the front and rear folding plates coplanar with or almost coplanar with the bottom plate.

When and as the bottom plate comes to its rest position, the continued retrograde movement of the mandrel serves to allow the following therewith of the spring load ed blank retainer plate so as to assume its respective position of rest.

By the unique arrangement hereof, I provide for the forming of a carton or tray from an economy style blank by themselves or simultaneously with a cooperant liner.

Such is allowed by means of a mechanism wherein the heating and pressure scaling functions are performed during a portion of both the in and on travel of the mandrel, and wherein the end folder and sealing plates are hinged to the bottom plate and are self-alignable therewith so as to travel with the carton or tray, with or without its cooperant liner, while it is being formed and sealed and to permit the equalization of the heat-sealing pressure exerted upon the respective end panel of the carton.

In FIG. 16, I have illustrated, in partial section, a formed carton blank 10 and cooperant liner L in combination with an end panel folding and sealing plate 340 wherein a pair of spring like members 343 and 345 cooperate to exert pressure directly against the upper or outer overlapping seam of the liner and against the dust flap adjacent the overlapping seam of the liner so as indirectly to bear thereagainst all so as to heat seal the portions of the overlapped seam of the liner outwardly of the respective end panel folding and sealing plate.

In FIGS. 17-22, I have illustrated formed containers or trays erected from the economy style blank of the invention with and without cooperant liners.

In FIG. 17, I have shown the economy style blank 10 of FIG. 1 erected as a tray incorporating the bottom panel glue tabs 32.

In FIG. 18, I have illustrated an economy style blank erected as a tray wherein the bottom panel glue tabs have been eliminated, a sometimes desired arrangement.

In FIG. 19, the economy style blank erected as a carton and modified to include a cover 17 and cover flap 19 has been illustrated.

In FIG. 20, I have shown the economy style blank with liner L cooperant therewith, same being in erected position as a lined tray.

In FIG. 21, I have shown a lined tray with certain panels of the tray being broken away for the sake of clarity wherein the rear panel glue tab 36 and the bottom panel glue tab 32 at the exposed end are clearly shown.

The lined tray of FIG. 22 is similar to the lined tray of FIG. 21 except that the bottom panel glue tab 32 has been omitted, as is sometimes desired.

By the method and apparatus hereof, I attain the simultaneous folding and sealing of a liner with a tray or carton wherein the liner is completely sealed so as to allow a moisture-proof dust-proof arrangement according to the specific types of liner materials being employed, and further wherein the folds of the liner are interlocked with each other and the liner is adhered to the inside of the tray or carton in certain areas so as virtually to olfer a one piece construction.

Although my invention has been described and illustrated herein with particular reference to specific carton forming structures, it should be appreciated that its utility and application extend beyond the particular types illustrated and its broad scope and concept comprehend the useful and novel features set forth when combined with any type of carton forming mechanism and thus, with respect to the scope of the invention, the foregoing material is to be considered as illustrative rather than limiting.

The invention is susceptible of various modifications and alternative constructions, and it is to be understood that I do not thereby intend to limit the invention to the specific forms above disclosed, but intend to cover all modifications, variations, alternative constructions and equivalents reasonably falling within the spirit and scope of the invention as expressed in the appended claim and within the meaning and purview and range of equivalents of this disclosure.

I claim:

In the method of erecting a paperboard carton blank into a formed container by heat sealing together portions of the paperboard carton blank, the sequential steps of, increasing the moisture content of the paperboard carton blank preliminary to erection for improving the heat conductivity and heat scalability of the paperboard carton blank, folding and rotating the panels and glue tabs into completely-formed position with the glue tabs deflected inwardly of their respective sealing panels for bringing the respective scalable components into heat sealing engage- References Cited by theExaminerment between a forming and sealing member interiorly of the erected carton and folding and sealing members eX- UNITED STATES PATENTS teriorly of the erected carton while allowing the escape 2,268,477 12/1941- Elmelfldorf of expanded trapped moisture in the paperboard blank 5-. 2,987,105 6/1961 Gebble through venting grooves in the adjacent faces of the form- 3,085,479 4/1963 Hoyrup et 93 51 ing member to prevent the formation of blisters due to paperboard delamination caused by the expansion of the FRANK BAILEY Prlmary Exammer' trapped moisture. BERNARD STICKNEY, Examiner.

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