US2321562A - Carton forming method and apparatus - Google Patents

Description

June 8, 1943. D. w. (:0? ETAL CARTON FORMING METHOD AND rmmwus Filed March 15, 1940 5 S'nets-Sheet 1 i NvENT oRs Don W C y Waler'l'. Edie? ATTORNEYS- June 1943. w. co Y E'rAL 2,321,562

' 'cAfi'roN FORMING METHOD AND 'APBARATUS i'Filed March 15, -1940 5 Sheds-Sheet 2 June 8, 1943- D.-'w.' cOY 2,321 562 L CARTON FORMING METHOD AND Am ms Filed uaronis, 1940' 5 Shetsi-Sheef. 4

INVENTORS C10,- 77012627 J7me? W, W ATTORNEYS- Dora W June 8, 1943. D. w. COY ETAL CARTON FORMING METHOD AND APPARATUS Filed March 15, 1940 5 Sheets-Sheet 5 mmms Don Walzier' Z 7' %%WJMTTO S Patented June 8, 1943 CARTON FORMING METHOD AND APPARATUS Don W. Coy, Chicago, and

Forest, Ill., assignors to pany of America, Chicago, 11].,

1 Delaware Walter T. Bitter, River United Biscuit Coma corporation of Application March 15, 1940, Serial No. 324,032

11 Claims.

This invention relates to an improved method and apparatus for forming cartons, particularly paperboard cartons, and although not restricted in all respects to employment with cartons in which certain portions are securedby means of thermoplastic adhesive material, is directed in some aspects to the formation of such cartons.

The main objects of the invention are to provide an improved method and apparatus for forming cartons from prefabricated carton blanks; to provide an improved method and apparatus for folding and securing in receptacle form prefabricated blanks provided with adhesive material on predetermined portions of the blanks; to provide an improved method and apparatus for folding into receptacle form prefabricated carton blanks having thereon dried thermoplastic material which becomes soft and tacky when subjected to heat; to provide in apparatus of the character indicated means for effectively softening thermoplastic adhesive material without danger of scorching or burning the material-"of the carton blank which carries the thermoplastic material; to provide a method and apparatus of the character indicated which will operate at relatively high speed and relatively quietly; and in general it is the object of the invention to provide an improved method and apparatus for folding into receptacle form prefabricated carton blanks.

Other objects and advantages of the invention will be understood by reference to the following specification and accompanying drawings sheets) wherein there is illustrated apparatus embodying a selected form of the invention and capable of performing the improved method of forming cartons.

In the drawings:

Figure 1 is a plan except that the right-hand end portion of the mechanism is shown in section as indicated by the line l-l of Figure 3;

Figure 2 is a section onthe line 2-2 of Figure 1;

Figure 3 is a side elevation of the right-hand end portion of the mechanism illustrated in Figure 1;

Figure 4 is a section on the line 4-4 of Figure 3;

Figure 5 is a perspective of a detail of construction also appearing in Figure 4.

Figure 6 is a section on the line 6-6 of. Figure 1;

Figure '7 is a section on ure 6;

Figure 8 is a perspective of a carton blank the line 'I-'| of Figtypical of the blanks which the apparatus illustrated is adapted to fold into receptacle, form;

Figure 9 is a perspective of a receptacle formed by the method and apparatus herein referred to from the blank illustrated in Figure 8;

Figures 10 andnll are perspectives illustrating different positions of the folding mechanism; and

Figure 12 is a section on an enlarged scale on the line l2--l 2 of Figure 4.

Referring now. to the drawings, the carton blank which the disclosed apparatus is designed to fold into receptacle form is formed of a suitable weight of paper or cardboard and comprises a generally rectangular member provided with creasing indicated by broken'lines indicated at 15 to divide the blank into a bottom-forming portion l'l, side wall forming portions l8, l8, corner-forming portions I9, 19 which extend integrally from the ends of the side wall portions l8 and are foldable along the crease lines l5, and end wall forming portions 20, 20.

The end wall portions 20, 20 are provided on their inner faceswith adhesive material as indicated at 2l, the same being preferably of a suitable-thermoplastic composition which when 'dry is hard and free from tackiness at ordinary temperatures. The thermoplastic adhesive material is to be selected with regard to the kind of material to be packaged in the receptacle, for example, if the product to be packaged is cheese or other materials which are flown into thereceptacle in more or less liquid form at high temperature, then the thermoplastic material should be such that it will not become soft or lose its adhesive properties until it is heated to a substantially higher temperature than that of the heated food product. Also, the material should be of such a character that it will not impart any flavor to the product packaged. Various thermoplastic materials may be produced which meet such requirements and they are considered preferable to conventional wet adhesives for many reasons well, known to those skilled in the art.

As indicated in Figure 9, the side walls l8, 18 are folded to upwardly extending, right-angular relation to the bottom wall H, the corner formthen folded inwardly from ing flaps l9, l9 are the respective side walls and the end walls 20, 20 are then folded upwardly into wall-forming position overlapping the outside of the said cornerforming flaps I9. The adhesive material 2|, if of thermoplastic character, is preliminarily heated so as to render it soft and tacky so that when the end wall portions 20, 20 are folded upwardly and pressed against the flaps l9, l9, said shown in Figure 3. The

Q carton blank stock or the in asuitable refractory .and without excessively lengthening the mechanism to 'hold -the carton in set-up condition, means is provided in the described apparatus for chilling the adhesive material when the blank path of travel of the carton blanks. For this purpose, the said heating devices 33 are secured tween the heating is formed to receptacle condition as shown in Figure 9.

The mechanism herein disclosed comprises at its left-hand end as viewed in Figure 1, an arrangement such as a hopper designated 22 for receiving a stackof blanks of the type illustrated in- Figure 8, the same being then in flat condition,

having thereon the thermoplastic adhesive material indicated at 2|. The blanks are fed one by one by suitable feeding mechanism not herein shown but such as shown, for example, in Patent No. 1,979,253 to Coy, for delivering the blanks one by one to a conveyor which propels the blanks to the folding mechanism. Such a conveyor is shown herein as comprising a pair of endless chains 23, 23, the same being supported by suitably mounted sprockets such as indicated at 24. The conveyor chains 23, 23 are continuously driven in unison and at a constant speed by a suitable driving connection with a main-power shaft indicated at 25, such connection including, for example, a chain 23 which extends around a sprocket carried by the power shaft 25, a sprocket carried by the shaft 21 which carries .the conveyor chain sprockets at one end of the conveyor, and a sprocket carried by a shaft 23 as best conveyor chains 23 are provided with suitable upwardly projecting ears or dogs 23, which are adapted to engage the rear edge of a carton blank so as to propel the same in unison with chains 23, 23.

The carton blanks are guided'in their travel on the conveyor chains 23, 23 by means of angle iron side members 30, 30, the horizontal flanges of which serve to support the opposite end portions of the blanks, and the vertical upstanding flanges of which serve to prevent sidewise shifting of the blanks. A centrally disposed bar-like member 3| serves to support the carton blanks intermediate the conveyor chains 23, 23.

While the blanks are being propelled by the conveyor mechanism, the thermoplastic adhesive material carried by portions, of the blanks is subjected to heat for softening the material to a suitable tacky condition. For this purpose it is preferred to avoid direct contact with either the thermoplastic material and means is provided for directing heat by radiation to the material to be softened. In this instance, such means comprises two or more elongated electricel resistance heating elements located at each side of the conveyor above the path of trawl of the opposite end portions of the carton blanks. Various forms of electrical resistance units may be employed and in this instance I contemplate the use of commercially available carbon rod devices which embody a carbon composition heating element 32 mounted body 32', so formed that it will reflect in the desired direction heat generated by the carbon rod 32.

Such units are designated in their entirety 33 and each is mounted independently of the other so as to be vertically adjustable relative to the 75 the movement of the conveyor tothe upper ends of straps designated 34, the lower ends of which are suitably slotted and clamped by means of bolts or cap screws 35 to a conveniently accessible frame part 38 which serves also to support the conveyor structure. It will be apparent that by varying the space bedevices 33 and the path of travel of the carton blanks a desirable control of the heating effect of the devices is provided. Furthermore, by providing two or more independently controllable electric units at each side of the structure, one or more of the units may be shut oil, thereby aflording further control of the adhesive softening operation of the mechanism.

Although the heatin operation is, at present, preferably effected by the means described, such means is not essential. Other heating means may be substituted.- For example, heat may be applied by means of plates or shoes heated by any medium which will produce the required temperature. Such plates may, if desired, be positioned on the side of the blanks opposite the side on which the adhesive is applied, thereby to avoid any possibility of direct contact with the adhesive material, or they may be mounted so as to be closely. adjacent but in sufllciently spaced relation to the adhesive bearing side of the carton blanks to avoid contact with the adhesive if such contact is to be avoided. However, in some cases 2 a wiping contacting arrangement may be preferable for various reasons.

The heating operation may also, for example; be effected by means of a current or blast of hot air directed over or against the adhesive bearing portions of the carton blanks.

It may be observed that the softening operation is dependent not only upon the temperature generated by the heating devices, the distance thereof from the material to be heated, the length of the heating device, and similar variables of the selected heating device, but also upon the speed of travel of the carton blanks past said heating devices. The indicated variables are readily adjustable, whereas the speed of travel of the conveyor and synchronized parts of the mechanism and the incidental variation in the production capacity oi the apparatus involve greater diiflcuties, either with the carton forming apparatus or with the resulting effect on. other operations in the plant wherein the apparatus is relied upon for cartons to meet a given production schedule.

The heating of the carton blanks. incident to the adhesive softening operation, sometimes tends to cause the blanks to curl upwardly and thereby become disengaged from the ears or lugs 29 of the conveying chains 23. To prevent or limit such curling, there are provided longitudinally extending bars I25, I25 (see Figs. 1 and 2) which overlie the path of travel of the blanks near their ends but spaced laterally from the adhesive bearing portions thereof. The number and location of the bars I25 may be varied in accordance with the requirements to control the curling eil'ect in each case. The bars I25, I25 may be mounted in any suitable manner and in this instance they are vertically adiustably suspended from cross I as shown at I23 which rest on the upper edges of the guide members 33, 30. The cross members may be free of attachment to the guide members so as to facilitate removal of the ,curl controlling structure, or they may be attached in fixed position if desired. However, one practical arrangement contemplates an unattached arrangement wherein the cross members are provided with shoulders such as I21 for positioning the structure transversely of the path of travel of the carton blanks. For adiustably supporting the bars I25, I25, the latter are suspended from the cross members by means of screws such as appear at I28, suitable springs I29 being provided for urging the bars to their lowest position as determined by the screws.

The conveyor chains 23, 23 deliver the carton blanks with the thermoplastic material thereon in tacky condition to folding mechanism which comprises a stationary outer forming member or die, and a series of inner forming members or mandrels designated 31 which are carried in predetermined spaced relation by endless conveyor chains 38, 38 and connecting bars 38'.

The conveyor chains v38, 38 extend around suitably journalled upper and lower sprockets 39 and 40, respectively, and they are continuously driven by means of intermeshing gears designated 4| 'behind the carton (Figs. 1 and 3) carried by the power shaft and the shaft on which the lower sprocket 46 is mounted. The travel of the inner form members 31 is guided at least in their operative zone by means of channel- like guide members 95, 95 in which the ends of the connecting bars 38 travel. Said channel-like members are carried by frame parts such as indicated at 9|,*9| (see Fig. l)

The inner forming members 31 are of generally rectangular form and of such size in cross-section that they will fit snugly within the cartons which are folded thereon. They are connected to the conveyor chain by means of relatively narrow ears 42 which are disposed rearwardly from the leading ends 43 of the inner form members.

The outer form or die comprises a transversely extending plate member 44 at one side, and a pair of transversely spaced plate members 45 and 46 at the opposite side. The upper ends of the said plates 44, 45 and 46 are disposed in alignment with the surface of a table plate 41 over which the carton blanks are received from the conveyor 23. For properly locating the carton blanks, one of which is indicated at B in Figure 6, over the ends of the forming plates 44, ,45 and 45, there are provided extensions 48 of the side guide flanges 30, and an abutment or stop 49 spaced outwardly from the forming plates 45 and 45.

For effecting delivery of the carton blanks to the stop 49, there is provided a reciprocating feeding device comprising a finger 50 pivotally mounted as shown at 5| on the lower end of an arm 52 which is mounted on a cross shaft 53, which in turn is pivotally mounted in suitable upright frame or bracket part such as indicated at 54. The shaft 53 has connected to it an arm 55 which is connected by a link 55 to a crank pin 51 carried by the continuously driven shaft 21.

A spring 58 or other suitable means is provided for normally urging the finger clockwise direction about its pivot mounting 5| on the lower end of the arm 52, and the outer or free end of said finger is adapted to ride in a groove'59 which is provided in the table plate 41. The free 'end of said finger 50 is further provided with an upwardly and forwardly extending ear 59 which insures proper engagement of the edge of the carton with the end of the finger 50 from which said ear extends.

It will be apparent that incident to the rotation of the crank 51, the finger 56 will be reciprocated. In its rearward or counter-clockwise movement as viewed in Figs. 3 and 6, said finger will ride over a carton being advanced by the 56 to rock in a conveyor 23 until the free end of the finger drops forward movement, the finger willtake up the feed movement of the carton blank and advance it to predetermined position against the stop 49.

One of the inner form members 31 next approaches the carton blank disposed over the outer forming member plates 44, 45 and 46 and serves. incident to its entrance between the plates, to fold the blank into U-shape form in which the side walls l8, l8 extend upwardly relative to the bottom wall H which is then disposed against the bottom or leading end 43 of the inner forming member.

Incident to such upward folding of the side walls |8, |8, the corner-forming flaps l9, l9 are also folded upwardly and they are next subjected to a folding operation which turns inwardly into the position illustrated in Figure 9. Such inward folding is effected by means of folding members 6| and 62, respectively, pivotally mounted on the adjacent sides of the outer forming member and provided near their upper ends with foldingears 63 arranged to engage the corner flaps l9 of the carton blank at the opposite ends of each of the side walls l8, l8.

Said folding members 6| and 62 are simultaneously actuated in opposite directions by means of a cam 54 carried by the power shaft 25 and operating against a roller 65, carried by one arm of a pivoted bell crank 65, the other arm of wh ch is connected by means of a link 61 to an arm 58 which is secured to a shaft 59 which carries the flap-folding member 6|.

, The shaft 69 is interconnected with the shaft 10 which carries the folding device 52 by means of arms 1| and 12 and a link 13 as best shown in Figure 3. provided for causing the cam-following roller 55 ta maintain contact with the periphery of the cam To prevent interference by the end wall portions20, 20 of the carton blank with the folding movement of the corner flaps l9, l9, said end walls 28, 20 are temporarily deflected to a downwardly inclined position as illustrated in Figure 11. The means for so deflecting the end wall portions 20 comprises rods 15, 15 which are aligned vertically with the normal position of the end wall portions of the carton blank when in operative relation to the forming dies. Said rods are carried by members indicated at 15 which are rigidly secured to a cross shaft-11, thelatter being rotatably mounted in the adjacent ends of arms such as 18 which are pivotally mounted at their opposite ends as indicated at 19 in portions of the frame members 54 provided for that purpose.

One of the arms 18 has connected to it through its pivot shaft 19, an arm 80 which is provided at its opposite ends with a roller 8| for engaging a rotary cam 82 carried by the driven shaft 21. The weight of the arms 86 and 18 and parts carried by their outer ends urges the arm to swing downwardly in a clockwise direction, causing the roller 8| to maintainoperative engagement with the cam periphery 82, so that incident to rotation of the cam 82 said arms 89 and 18 and the parts carried thereby are oscillated, the rods 15 being thereby reciprocated in a vertical direction. To maintain the rods 15 in a, substantially vertical I position at all times, the shaft 11 has rigidly secured to'it a link 83 which extends upwardly and is pivotally connected as shown at 84 to the blank. Upon its return or A spring 14 or other means may be ment, is transmitted from the ton end wall portions necting element width to seriously hinder the folding of' mediate its ends, the arm ll for causing the cam-following roller 32 to mounted in portions of the frame membe It provided for that purpose. It will be apparent that the parallel arm arrangement II and connections therebetween serve to maintain the deflecting rods in substantially vertical position at all times. a

It will be further observed cam 02 to the arm II, through the adjacent arm I! and link It to the immediate overlying arm 85 and thence through the shaft I to the arm 85, link 83 and arm II at the other side of the apparatus.

It being understood that the various cams and operating elements referred to are properly that rocking moveon the outside of the arms II which are in turn is suitably pivotally equipped with means for folding upwardly the end wall portions 20, into overlapping relation flaps I, I8. such devices being caused to operate incident to the down-' ward movement of the partially folded blank on the end of the inner memberll.

Said end wall folding devices comprise the upper ends 96, 96 of plate members 91, 91, which timed in their operation, it will be apparent that the cam I2 is so adjusted the depressing rods II to move downwardly to deilect the carton blank end portions II, II as shown in Figure 11, just prior to the time the cam 64 actuates the folding devices I and 52. Adjustment of the extent ofdeflection of the carmay be made by adjusting the vertical position of the rods 15, II in the holders it, by modifying the cam .2, or by other well known means. The timing of the operation of the deflecting members ll, 18 and the folding members ii and i2 is so adjusted that these parts operate immediately after the II, It are folded upwardly on the inner forming member 31 and during the con tinued travel of the same.

The space between the folding plates 45 and 43 through which the inner form; member con- 42 passes is not of sufllcient the side wall ll of the carton since the carton blanks are creased to facilitate such folding. However, it is preferred that means be provided forkeeping the upper folding edge between said plates "and II and bers 45 and 48 and which member I! is of such 1 ofthe apparatus (see Figures 1 and 6).

roller 92 which is adapted to carried by the rotatably driven shaft 28. The cam 93 is so shaped and it timed relation to the operation of the mechanism that the member 81 will be moved into operative relation with the folding plate members 45 and 6 before the inner forming member 31. reaches its operative relation to the folding structure and so that the member 81 is withdrawn in ample time to permit the connecting neck or ear I! and other parts to travel downwardly through their normal path of movement. A spring 94 or other suitable means is providedmaintain operative contact The outer die or with the cam 83. forming member is also and formed as to cause side wall portions,

the side wallsof extend transversely between depending extensions of the side folding plates 44 and 45, 46, the upper ends of which plates constitute the means for efl'ecting upward folding of the side wall portions It, ll of the carton blank. It

when the inner forming will be apparent that member 31 carries the carton blank downwardly between the upper ends of the plates 91, 91, the end walls 20, 20 of the carton blank will be folded upwardly into overlapping relation. to the previously'in-folded flaps l9, IS.

The plates 91, 91 at opposite ends of the path of travel of the folded carton blank or receptacle may be disposed in such position that they press the end walls' 20, 20 into tight contact with the underlyingflaps l9, I! so as to produce an effecdrag against the hesive material.

' rection that their respective rollers tive bond between the overlapping parts through the agency of the reactivated thermoplastic ad- However, th application of manner would create a serious advancing movement of the inner form member with the receptacle thereon, and the action incident to such a drag is somewhat objectionable for other reasons. In this instance there is provided a series of pressure rollers respectively designated SI for cooperation with each end of the inner form member 31. Said pressure rollers are Journalled as indicated at 99 in suitable brackets Ill. (see Figures 4, 7 and 10) and each bracket I" is pivotally mounted as indicated at ill in the adJacent side members l4, l5 and 46.

The axis of the pressure in such a meat of the respective brackets 100 about their pivot mountings will effect movement of the respective rollers toward or from the adjacent sides of the inner forming member 31. purpose of urging the rollers 98, 98 toward the adjacent sides of the inner form member 31 Figure 4, that expansion of the springs ll! serves to cause the adjacent brackets ill. to rock in such a ditoward the inner forming member 31. able means for limiting the extent of such inward movement may be provided in the form of adjustable set screws Ill which are adapted to engage suitably provided frame or other por-' tions such as indicated at I M.

It will be apparent that sively engage the receptacle formed on the leadton structure by the selection and insertion of springs I02 of the desired strength.

During the travel of the receptacle between the pressure rollers to squeeze the overlapping carton portions tightly together. To insure permanence of the bond effected by I the moving receptacle carried by the thermoplastic adhesive material, it is preferred that the same lapping carton portions are relieved from all pressure. For this purpose there are provided chilling shoesor blocks I05, I05 respectively associated with the opposite series of pressure rollers 00, 90 (see Figures 4 and 12). Each such shoe has its inner face finished to such smooth ness 'as to avoid the creation of too much drag on the inner form-- ing member 31 and thereceiving ends of said shoes are relieved as indicated-at I06, so as to facilitate entrance of the form-carried receptacle between theshoes.

Each shoe I05-is mounted between the respectively adjacent side plates 44, 45 and 48 for'movement bodily toward and from the path of travel oi. the inner forming member. For this purpose there are provided links such as indicated at I01, I01, at opposite sides of each shoe, such links being pivotally mounted as indicated at I00. I08 at their upper ends in the said side plates 44, 45 and 45 and having their lower ends pivotally connected as indicated at I09, I09 to the shoe intermediate its upper and lower ends. A spring I I is interposed between each shoe I and another frame or similar portion III, such spring serving to normally urge the shoe to move inwardly toward the path of travel of the inner forming member 31. The extent of such inward movement may be limited by suitable adjustable stop screws H2, H2 which are spective shoes and fit slidably through suitable openings in said frame portions II I.

For cooling the shoes I05. they are provided with suitably formed internal passageways such as indicated at 3 which are provided with inlet and outlet conduits I [4, 4, whereby water or other cooling medium may be circulated through the said passageways. Theconduits I I4, I I4 may include at some suitable point a flexible hose or other connection which willpermit free movement of the shoes inwardly and outwardly.

When the inner forming member 31 with a receptacle formed thereon emerges from between the cooling shoes I05, I05, the receptacle is ready to be stripped from the inner forming member 31, the thermoplastic adhesive material having then been set sufiiciently to maintain the receptacle in its set-up condition.

For stripping the receptacles from the inner forming member 31, there are provided in association with the opposite sides of the inner form member 31, endless chain or belt conveyor members I I5, I I5 which are carried by suitable means such as upper and lower sprockets H5 and 1, respectively, such sprockets being suitably rotatably mounted in frame parts as best shown in Figures 3 and 4 of the drawings.

The conveyors H5, 5 are so arranged that one reach of each conveyor travels downwardly in outwardly spaced but substantially parallel relation to the travel of the respectively adjacent sides of the inner forming member 31 and they are continuously driven at a speed of travel which is substantially higher than the speed of travel of the inner forming member 31. Each conveyor is provided with a suitable resilient finger H8 having a laterally extending head or lip H9 at its upper end which is adapted to engage the upper edge I20 of the respectively adjacent end walls of the receptacle on the inner forming member. Each of said fingers I I8 is so arranged that the inner ends of their respective lips H9 will first engage the adjacent sides of the inner threaded into the re-' be chilled before the over- 4 between the fingers H8, H8 and form 31 somewhat above the said edges of the end walls of the receptacle and incident to the higher speed of travel of the conveyors H5, II 5, the lips of said fingers will engage said receptacle edges and ultimately pull the receptacle from the end of the inner forming member 31. The receptacle, 'of its own weight, will drop from may be received by a conveyor or other preferred means.

For driving the conveyors H5, H5, there is provided a shaft I2I suitably Journalled in the frame work of the apparatus and connected by pairs of bevelled gears indicated at I22, I22 to the shafts I23 which carry the lower sprockets III. The shaft I2I is in turn driven by a chain I24 which engages suitable sprockets carried by the shaft |2I and another driven shaft such as the shaft 21. The speed at which the conveyors I I5, I I5 are driven may be determined by proper selection of sprockets which cooperate with the chain I24 and by proper selection of the intermeshing gear pairs I22, I22. In this instance, the sprocket on the shaft I2I which is driven by the chain I24 is of much smaller pitch diameter than the driving sprocket on the shaft 21, so that the speed of rotation of the shaft IN is increased to effect the desired result.

The described apparatus, being continuous in operation and being free from noisy operating reciprocating mechanism, is both rapid and quiet in operation. Because of its improved arrangement for applying pressure to the overlapped parts of the receptacle, it has been found to be highly efficient in the forming of cartons .which employ thermoplastic adhesive material for effecting the bond between such overlapping parts and its arrangement for chilling-the adhesive material to set the same after the extended application of pressure contributes materially to its successful operation.

Although the apparatus as shown is arranged for setting up prefabricated carton blanks, it will be apparent to those skilled in the art that instead of providing mechanism for feeding such prefabricated blanks, mechanism for forming such blanks may be substituted, such mechanism then including means for applying the thermoplastic adhesive material to the selected portions of the carton blanks. In such a case, the employment of the heating units 33 may possibly be dispensed with, although even in such case they maybe desirable for the purpose of maintaining the adhesive material in its tion until the carton blank reaches the folding elements of the apparatus.

Many changes in the structure may be made without departing from the spirit of the invention, the scope of which should be determined by reference to the following claims, the same being construed as broadly as possible, consistent with the state of the art.

I claim:

1. The method of forming a carton which comprises the steps of providing prefabricated carton blanks having thermoplastic adhesive material on predetermined portions of the blanks, propelling the carton blanks edgewise, effecting softening of the adhesive material by directing radiated heat thereto during the travel of the blanks and then, while the adhesive remains soitand tacky, folding the blanks-into receptacle form and pressing together the portions thereof to be united by said adhesive.

2. Apparatus for forming cartons employing thermoplastic material for adhesively unitin most desirable tacky condiv overlapped portions comprising meins for pro-- pelling carton blanks having thereon dried thermoplastic material, heat radiating means disposed adjacent but in spaced relation to the path a of travel of the blanks for radiating heat to said dried thermoplastic material so as to soften the same to tacky condition, means for adiustably a,sa1,sea

mounting said heating means for movement toward and from said path of travel, thereby to facilitate regulation of the softening eiiect of said heating means, means for folding the blanks to receptacle form with predetermined portions overlapping the adhesive-bearing portions, and

means for resiliently pressing together said overlapping portions.

3. Apparatus for forming cartons embodying thermoplastic material for adhesively uniting overlapped portions comprising means for prothe blanks to receptacle form with predetermined portions overlapping the adhesive-bearing portions, means for resiliently pressing together said overlapping portions, means for chilling and thereby setting the adhesive between said overlapping portions, said chilling means comprising a presser member mounted for movement toward and from the overlapped portions of the carton, means yieidingly urging said presser member to ward said overlapped portions, means for limiting such movement, and said presser member being provided with a passageway therein for the circulation therethrough of a cooling medium.

4. In apparatus of the class described, means for forming and propelling cartons, mechanism for applying pressure on overlapped carton portions comprising a pair of side plates, a pluralit of relatively independent brackets pivotally mounted on said side plates, a roller iournalled in each of said brackets on an axis eccentric with the pivot axes oi the respective brackets, spring means acting on said brackets to urge the same to rock in such direction as to urge the respective rollers against said carton portions, means for limiting the spring-eil'ected movement of said rollers, and a pressure block for engaging said portions after the same pass said rollers, said pressure block being mounted in said side plates for movement bodily toward and from said, overlapped portions, spring means for urging said block toward said overlapped portions, means for limiting the spring-effected movement of said block, and said block being provided with a passageway therein for the circulation therethrough of a heat-exchanging medium.

5. Apparatus for forming cartons comprising an outer forming member, an innner forming member adapted to move continuously in a predetermined direction through said outer member to cooperate therewith to fold walleforming por tions of a carton blank into receptacle-forming position relative to another portion of the blank, means independent of said outer member for folding corner-forming flaps of the blank into receptacle-forming position, reciprocable means movable in the direction of movement of said inner member for moving certain wall-forming portions of the blank out of the way of said flaps during the folding movement thereof, and means for folding said last mentioned portions into wall-forming position overlapping sa d fo ded flaps.

"6. Apparatus for forming cartons comprising an outer forming member, an inner :iorming member adapted to'move continuously iii' a predetermined direction through said outer member for cooperation. therewith in folding carton blanks into receptacle-forming condition, means for propelling said inner forming member comprising a continuously propelled endless conveyor. an ear spaced rearwardly from the leading end of said inner member, projecting laterally therefrom and secured to said conveyor for interconnecting said inner member and conveyor, said outer forming member being provided with a slot in a portion thereof for permitting the passage therethrough of said ear, auxiliary outer forming member meansadapted to be inserted in said slot to complete said outer forming member so. as toprovide continuous-forming surfaces for cooperation with the leading end of said inner member, means for mounting said auxiliary member for movement into and out vofsaid slot, and means for efiecting such movement of said-auxiliary member in timed relation with the travel or said inner member through said outer member. v

'7. Apparatus 1'or forming cartons employing thermoplastic material for adhesively uniting overlapped portions comprising means for propelling carton blanks having thereon dried thermoplastic material, heating means for softening to tacky condition said thermoplastic material, said heating means comprising two or more elongated electrical resistance devices arranged longitudinally of said propelling means so' as to be adapted to successively heat carton portions propelled therepast, said electrical devices being adjustably mounted in spaced relation to the path of travel of said carton blanks so as to eifect softening of said thermoplastic material by heat radiated from said devices, the heating eflect of said heating means being controllable by the capacity 01' each heating element to be turned on or of! independently of the other and by the adjustability of the spacing of the heatingmembers relative to the path of travel of the carton blanks, means for folding the blanks to receptacle form with portions thereof overlapping the adhesivebearing portions, and means for pressing together said overlapping portions.

8. Apparatus for forming cartons employing thermo-plastic material for adhes'ively uniting overlapping portions, comprising means for propelling carton blanks having thereon dried thermo-"plastic material, an electrical. resistance device arranged longitudinally of said propelling means, so as to be adapted to heat carton portions propelled therepast, so as to eflect softening of said thermo-plastic material by heat rapelling carton blanks having on portions thereof dried thermo-plastic material, an electrical resistance device extending longitudinally of said propelling means and disposed in-spaced relation to the path of travel of the blanks carried by said propelling means to effect softening of said thermo-plastic material by heat radiated from said device when energized, means for folding the blanks to receptacle form with portions thereof overlapping the softened thermo-plastic-bearlng portions, and means for holding together said overlapping portions while said softened thermoplastic material sets.

10. Apparatus for forming cartons employing thermo-plastic material for adhesively uniting overlapping portions, comprising means for propelling carton blanks having on portions thereof dried thermo-plastic material, a carbon rod electrical resistance device extending longitudinally of said propelling means and disposed in spaced relation to the path of travel of the blanks carried by said propelling means to effect softening of said thermo-plastic material by heat radiated from said carbon rod device when energized, means for folding the blanks to receptacle form with portions thereof overlapping the softened thermo-plastic bearing portions, and means for holding together said overlapping portions while said softened thermo-plastic material sets.

11. Apparatus for forming cartons employing thermo-plastic material for adhesively uniting overlapping portions, comprising means for propelling carton blanks having thereon dried thermo-plastio material, heat radiating means disposed adjacentbut in spaced relation to the path of travel of the blanks for radiating heat to said dried thermo-plastic material so as to soften the same to tacky condition, means for folding the blanks to receptacle form with portions thereof overlapping the adhesive-bearing portions, and means for holding together said overlapping portions while said softened thermo-plastic material sets.

7 non w. COY.

WAL'I'ER T. amen

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