US2670027A

US2670027A - Machine for sealing cartons

Info

Publication number: US2670027A
Application number: US209237A
Authority: US
Inventors: Wilferd C Gigler
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-02-03
Filing date: 1951-02-03
Publication date: 1954-02-23
Anticipated expiration: 1971-02-23

Description

Feb. 23, 1954 w. c. GIGLER MACHINE FOR SEALING CARTONS 3 Sheets-Sheet 1 Filed Feb. 5, 1951 INVENTOR.

WILFERD c. GIGLER ATTORNEY Feb. 23, 1954 w. c. GIGLER MACHINE FOR SEALING CARTONS 3 Sheets-Sheet 2 Filed Feb. 5, 1951 INVENTOR.

WILFERD c. GIGLER ATTORNEY W. C. GIGLER MACHINE FOR SEALING CARTONS Feb. 23, 1954 Filed Feb 5, 1951 3.Sheets-Sheet 5 z B H H ow 2o oooooae @60@ o mwm 0 mm mp mm m I E 3 1 1 mm m c. E. E 2 \B M i 2. 8.

INVENTOR.

Wl LFERD 0. GI GLER ATTORNEY Patented Feb. 23, 1954 cama iwasha Applicationillcbruamfi, 1951; ,SerialtNo.\209,237.-.n v

3-ClaimSi*-- (Cl. 154- 42) This inventiomrelatesin generalize cardboardi cartons and the" like; particularly to cartons of rectangularshape; used as shipping and storage; containers" for various"; products andi requiringi sealing 'of the cartoni; r

More specifically thisinvention' relates "to cartons. which are" producediin"knocked-downtimditionand-thereafternare set up'," f11led, and=finallyj sealed, and the" inventioni'is "concerned" specially with-the finarsealingtof:such' cartons: 1

Rectangular '"cartonsuof the type" indicated are; customarily formed with a" plurality. of flaps at top and bottomygzthe fi'aps being" hinged to the side walls; andtthesealingtofthe" tops and Ibot toms-of the cartons'is generailyidone'eitherby 5 applyi1ig-gummed tape :over "the "abutting'iedges"? of theouter flaps or-byfgluingsuch'flaps' down on the underlyingflap's attopendbottom;."Eitlier? procedure requires a' considerable amount- ;of .S' labor andxtime;:'and this:is 'particularlyjtrue; if the cartons which are" being; sealed. are of1dif- I ferent sizes: Thus while thereare'machines for J applying'moistened gummedtape'to carton flaps for" the sealing-ofPthe' same: nevertheless "when thecartonsi-a-reofvarioussizes "and-fwithoufiany' separate operations;

An" object ofthei. presentfinvention is to, {2110 11 vide', "an improved "canton" which 'can' be'sealed. withfa' minimum of-time tand'eifort: 1"

Another-object of tlieiinventi'orr is' to provi'de.

animproved-.7cartomadapt'ed'ffor, isealing by (me; chemical "means which "means willbe capable'ilofj, being operated largely automatically,

A :related'object of the =-invention" is "to pmvide. a,

an improved carton. on which the sealing .'of "the.,;

flaps on top and' ibottom' can take: place vsir'nu'lel taneouslyw' An 'iadditional object oi "the": invention I is,- Jto. 1 providea'special'carton 'sealingdevicespecifically; adapted-for 'use'witlr 'sucli'" improved Zjcartons. Li

A" further :object' oftlie invention isytoliproyide an'improved" sealable carton andmeans for iseal ing" "such carton which willf'be. practicalio i158, when such cartons of various sizes, are. requirem to be-sealewin succession.

'I'hes'eobj ects and ,I other; incidental advantages A I I have loeen a'loleto attainsatisfactorily' by. having' special heat-sealable adhesive *applied to the carton flaps-in thev manufacture of the'carton;.;:

inathefinal*sealingjoperation of the 'filldic'ar: ton; as will be hereinafter briefly, (described with reference .to the accompanying, drawings.

Eig.'11i a plan of" theifinihd blank for. my? improved" carton;

FigZjZiSLa' plan view of the same 'blank,. .witl1" the; ends securedttogether to complete the sidestructure, "and' with the blank folded." L01" knocked-down position;

Fi'gzBtis a. perspective'view ofgthecartonlsetup and' filled and "witli'theitop" flaps'ready for-clos 1' Figt' l" is, a similar'view of the carton" with "thef top" sealed;

Fig? .5 'i's'an'. elevation10f a machine". for 'pre-' paringwhe" cartomblank;

Fig. 6 is a topplanviewoffthesame; and" Fig: "'7, is "atdiagrammatic elevation of "theisealingmeans'hywhi'cli" the .finalsealing ofithebottomand" top. "of each carton is achieved: auto matically and regardless of the sizeof thecarto f" The'carton blanksshown in Fig: "1' is; more-"or"- less of the customarypshapefor blanks'forrec tangularoartons: Thebroken'. line'sin this'figure indicatethez fold 'linesfior "the wvariousiwalls" and= 'fl'ap"s." j Thefl'section'portions' 'I I I I 2 and I3*constiti1te the sidewalls. The'fl'aps" I4 and I 5-=iare"the:inner fia-pst' for the'b'ottom" and the. flaps=- I6- and *II are the outer flapsfor-the 'bote i tom.-'Simi1ar1y the"flaps I8 "and" I9 are the" inner "flaps "for" the top and "the-flaps: 20 Sandfi are-the outer flaps for"the "top;: The faces shown of'thesections and flaps'are'a'll insi'de'faces respect to the final cartoni In thefinishingof the-'"blank; heat=softenable glue or "adhesive-is applied "tothe alternate flaps", 20 and-"21, constituting the 'outer' flaps: for the topyof-the -'carton,rand also *simil'arlj? toj'the: al-" ternate" flaps. IB- and 'I'l constitutingthe' outer; fiaps =for*thebottom of the carton; as will later appearr 1 In --the'-carrying out of my invention'it" is sufiicient if the heat-softenable, adhesivefisapplied to-these -'outer fiaps'only in lim'ited areas on-'- the-same; such as in' the areas indicated at .1," in Figi 'li InTigsi- 5 and-6-I sliowa-sirnpledevice1w for "completing the forming of the? blank? an'di': applying the-= heat softenable adhesive at these areas-w:

Ref erringt toFi'gsf 5 'andf'fi; whichiare more; or lessidiagrammati'ci and"'are not drawn to; any; seale ;thei'upper'slotter; knife rolls 'and. .tlie' co I operating'lower'slott'er rol1s',",for forming the'sl'obs ln between'thefl'aps II ,l 9,1 I 'I;1TI'5 ',"

etcmofuthelblanlei areindicaitedbjr'tliereference characters

23 and 24. The lower slotter rolls 24 are secured to a shaft 25. A gear 26 (Fig. 63) secured near the end of shaft 25 meshes with a gear 21 secured on the end of the shaft 28, the upper slotter knife rolls 23 being carried on the shaft 28. Suitable means (not shown), such as an electric motor, drives the shaft 26 and with it the shaft 26 and the slotter rolls. The upper slotter knife rolls 23 have knife segments 29 on their peripheries which enter grooves in the lower slotter rolls 2 3. As the carton blanks (indicated at y in Fig. pass under and beyond the slotter knife rolls 23 they are supported at their outer edges on rails or skid plates 36, and since the cardboard from which the carton blanks are made is fairly stiff the supporting of the blanks at their outer edges by their rails 36 is sufficient to hold them horizontal.

A pair of glue pans 31 are located beyond the slotting rolls and below the path of travel of the carton blanks. These pans 3| are supplied with heat-softenable adhesive and are kept heated by steam or by electric elements (not shown) at the proper temperature for maintaining the adhesive in the pans in a liquid or viscous condition. A pair of glue-applying rolls 32 are located in each pan 3! and are secured on a common shaft 33. A sprocket wheel 34 is mounted on the end of the shaft 63 and a sprocket chain 35 connects sprocket wheel 34 with a sprocket wheel 36 mounted on the end of driven shaft 25.

Upper and

lower draw rolls

31 and 38, mounted on

shafts

39 and 46 respectively, are located between the slotter rolls and the glue pans, and are adapted to engage each carton blank as it leaves the slotter rolls and move the blank along on the rails 36 and over the glue pans to a second set of upper and lower draw rolls 4! and 42 mounted on the

shafts

3 and 44 respectively.

A gear 54, secured on shaft 33, meshes with a pair of intermediate gears 65 and 36 which in turn mesh with

gears

51 and 48 respectively mounted on shafts 3%} and id.

Gears

41 and 43 in turn mesh respectively with

gears

49 and 56 secured to shafts 39 and it respectively.

The glue-applying rolls 32 are mounted at such level that they will come within a small fraction of an inch of the under face of the carton blank when the latter is supported on the rails 36. In order to bring the desired flap portions of the blank into contact with the glue-applying rolls 32 I provide a series of adjustable segments 5i mounted on a shaft 52, which shaft extends parallel to the sha t 33 of the glue-applying rolls 32. The radius of the arcuate peripheries of the segments 5! is of sufiicient length to cause these segments, when coming into contact with a carton blank, to press the blank downwardly sufficiently to cause the blank momentarily to contact the underneath glue-applying rolls. A gear 53, secured to the end of shaft 52 engages the gear 55, thus causing rotation of the shaft 52 and segments 5! with the rotation of the glue-applying rolls 32.

Thus, as will now be apparent from Fig. 6, after each carton blank leaves the slotting rolls it passes over the glue pans and receives applications of the heated adhesive on the flaps 2|, 26, I1 and 16. After leaving the second pair of draw rolls 4| and 42 the carton blank is dropped on to a suitable conveyor, indicated at z in Fig. 5. The adhesive on the carton flaps dries almost immediately and the finished carton blank, in the form illustrated in Fig. 1, may be shipped or stored in such position, or may have the ends of the wall portions secured together so as to place the carton more in readiness for use. This is done by securing the end wall fiap 22 (Fig. 1) to the wall portion i3, this securing being done either by stapling or by gluing, whereupon the carton will be in condition ready for immediate use but in knocked-down condition, and will appear as illustrated in Fig. 2. 1

When the carton is to be filled it is set up in the usual manner with the inner and outer bottom flaps folded in. However, with my improved carton, the sealing of the bottom fiaps is not done until the final sealing of both top and bottom is performed. The set-up carton is placed on a suitable support, platform or conveyor, and is filled. When the filling is completed the two inner top flaps l8 and L! are folded over (Fig. 3) and finally the outer top flaps 2i! and 2i are folded over. The carton is then ready for the final sealing of the top and bottom, an operation which takes place quickly and automatically with my improved carton and with the special sealing means to be presently described, and the final filled and sealed carton will then appear as illustrated in Fig. 4. The means by which the sealing of the top and bottom carton is performed is diagrammatically shown in Fig. 7.

In Fig. '1 an endless conveyor 55 delivers the cartons, as they are filled, to the heat sealing means, diagrammatically illustrated, the filled cartons being indicated by the reference character 0. From the conveyor 55 the filled cartons are delivered to a gravity roll section or series of rollers 56. A pair of conveyor chains 51 located at the ends of the rollers 56, moving in unison and carrying transverse flight bars 58, pass around pairs of sprocket wheels 59 and 66. On the shaft to which the sprocket wheels 59 are secured a pulley 6| is also secured and this pulley 6| is driven (in clockwise direction as viewed in Fig. 7) by means of a belt 62 from a motor 63.

The series of rollers 56 are in two groups and a stationary platen 64 is located in the space between the two groups. The platen 64 contains electric heating elements connected to a suitable source of electric energy and a thermostatic heat control (not shown) so that the top face of the platen can be heated to, and maintained at, a desired predetermined sealing temperature.

As each filled carton is delivered from the conveyor 55 on to the rollers 56 it is engaged by one of the flight bars 58 and moved along (from left to right as viewed in Fig. 7) over the first group of rollers and on to the platen 6 1 until the carton engages a spring-controlled finger of an electric switch 65. A pair of wires connect the switch 65 with a time switch 66 and the closing of the switch 65 results in actuation of the time switch 66.

An air cylinder 61 operates a piston and a downwardly-extending piston rod 68. A platen 69 is secured to the lower end of the piston rod 68. This platen 69, like the platen 64, is provided with electric heating elements and a thermostatic control (not shown) so that the platen 69, and in particular the bottom face thereof, can be maintained at a predetermined desired sealing temperature. The cylinder 61 has ports 10 and 1| near the top and bottom ends respectively and these ports are connected through the medium of an electrically operated control valve 12 to a suitable source of compressed air (not shown), received through the pipe 13, and to an exhaust port 14. Thus in one operating position of the valve 12 air will be delivered to the lower port 1i of the cylinder 61 and exhausted from the upper port 10, thus moving the piston rod 68 and platen 69 upwardly, while another operating position of the electrically-operated valve I2 will reverse the flow of air to the cylinder 6l, producing downward movement of the piston rod 68 and platen 69.

When a carton engages the finger of switch 65, causing the time switch 66 to be actuated for a predetermined interval, the time switch, during the resulting period of such actuation, opens the circuit to the motor 63, temporarily stopping operation of the motor 63, and causes the valve 12 to be turned temporarily into position whereby compressed air will be delivered into the upper port it of the cylinder 61 and allowed to be exhausted from the lower port H. Consequently when the carton has been moved on to the lower heated platen 64 and comes into engagement with the finger of the switch 65, the result is that, for a predetermined interval as determined by the time switch 66, the movement of the transverse bars 58 will cease while the upper heated platen 69 will move down on to the top of the carton. During this interval, the heat from the two

platens

64 and 69 softens the adhesive on the outer flaps at the bottom and top of the carton respectively and this heating and pressing of the flaps results in the sealing of the carton bottom and top. A few seconds is all that is required for the heat sealing operation, the heat from the two heated platens being suflicient to soften the adhesive on the inside of the adjacent flaps of the carton without causing any scorching of the flaps during the brief interval of contact.

After the expiration of the interval for which the time switch 66 is set, the switch 66 returns to normal position, closing the contact to the motor 63, causing the motor 63 to resume operation, and changing the position of the valve 12 back to normal position and causing the delivery of compressed air into the lower port ll of cylinder 6'! and lifting the platen 69 from contact with the carton. The carton is then moved off of the lower platen 64 and on over the second group of rollers.

Since the carton remains in contact with the heated platens for such a short time, I have found it preferable to hold the carton flaps in sealing position for another brief interval while the adhesive cools and is given an opportunity to set again. For this purpose I provide a second but unheated platen 15, so arranged as to bear down on the top of the carton while the carton is again temporarily halted on the second group of rollers.

A second electric switch 16 is so positioned that a carton below the second platen 15 will engage a spring control finger of this switch 16. The switch 16 is similar to switch 65 and, as indicated in Fig. 7, is also connected to the time switch 66. A second cylinder Tl, similar to cylinder 61, has a piston and piston rod 13 and the unheated platen 15 is secured to the bottom of the piston rod 73. The control valve 12 also controls the passage of air into cylinder 11 in the same manner as into the cylinder 61. Thus when a carton contacts the second switch 16 the motor 63 is again temporarily stopped and the cold platen i is moved down on to the carton located below the platen. This movement of the platen 15 holds the top flaps of the carton in pressing engagement with the underneath flaps while the adhesive is given an opportunity of cooling and setting. Then, after termination of the period as provided by the time Switch 66, the second platen I5 is returned to its normal raised position and the carton, with the sealing now completed, is moved further along to the right and finally delivered on to the conveyor 19.

The piston rods 68 and 18 are made of sumcient length so that their respective platens will engage the tops of even small cartons. However, piston rod 68 is not made long enough to permit the platen 69 to be moved down into actual contact with the bottom platen 64, and likewise piston rod i8 is not long enough to permit the platen 15 to reach the rollers beneath the platen, but suitable springs or other cushioning means (not shown) preferably are provided for the pistons in both cylinders 61 and 11 to stop the movement of the pistons at the end of their maximum travel in either direction without excessive vibration or shock to the supporting mounting for the cylinders.

It will be evident from this description and from Fig. '7 that cartons of various sizes can be handled with the sealing mechanism which I have devised, and that when a carton is set up and filled and the top flaps are folded over into position for sealing, only a minimum amount of attention is required for the completion of the sealing. No adjustment of this sealing mechanism whatsoever is required for cartons having a considerable range of size. This is a very important feature of my invention.

There are several heat-softenable adhesives on the market which can be used satisfactorily in my improved carton. One such adhesive which I have found very successful is manufactured by the Monsanto Chemical Company of Seattle, Washington under the trade-name of Vuecote and contains castor oil and resin. The time switch 66 must of course be set in accordance with the time required for softening the adhesive on the carton flaps and with regard to the amount of heat furnished by the

heated platens

64 and 69. The heat-softenable adhesive used should of course be capable of softening in a few seconds under the influence of the heat which may practically be applied to the carton flaps, and the adhesive must also be capable of setting again I in an equally short time.

Modifications in the construction of the heat sealing device, which I have illustrated and briefly described, would of course be possible within the scope of the invention.

I claim:

1. In a device for heat-sealing a carton of the character described having top and bottom flaps treated with heat-softenable adhesive, a heated platen positioned to support said carton, means for moving said carton onto and off of said platen, a second heated platen located above said first platen and in substantial registration therewith, means for moving said second platen up and down, a control for said platen-moving means, said control normally maintaining said second platen in raised position, means operating said control to cause temporary downward movement of second platen, said control also connected with said carton-moving means, whereby to halt operation of said carton-moving means'while said second platen is resting on the top of said carton, an unheated platen located beyond said first and second platens and above the path of said carton, said carton-moving means acting to move said carton from said first platen into position beneath said unheated platen, means for moving said unheated platen up and down, and a control