US2266054A - Apparatus for sealing containers - Google Patents

Description

Dec. 16, 1941. R. E, LQWEY HAL 2,266,054

APPARATUS FOR SEALING CONTAINERS Filed Sept. 23, 1939 4 Shets-Sheet 1 Dec. 16, 1941.

R. E'. LOWEY ET AL'. 2,266,054

APPARATUS FOR SEALING CONTAINERS Filed Sept. 25, 1939 4 Sheets-Sheet 2 Dec. 16, 1941.

E. LOWEY ETAL APPARATUS FOR SEALING CONTAINERS Filed Sept. 23, 1939 4 Sheets-Sheet 3 V Patented pee. 16, 1941 APPARATUS FOR SEALING CONTAINERS Roy E. Lowey, Cook County, and Edgerton A. Throckmorton, Kane County, 111., assignors to Container Corporation oi America, Chicago, 111., a corporation 01' Delaware Application September 23, 1939, Serial No. 296,236

- UNITED STATES "PATENT oFFioi: I

3 Claims.

The present invention relates to apparatus for sealing containers and more particularly relates to the top sealing of tubular cartons having overlapping end flaps.

\ One object of the present invention is to provide a simple and effective form of apparatus for sealing the flaps of a carton in a closely associated manner whereby not only sifting or leakage of the contents of the carton will be prevented but the carton will also be sealed in a substantially gas tight and vapor proof manner.-

Another object is to provide an efiective appa- 'ratus for sealing the flaps of acarton whereby the flaps may be sealed in a closely related manner irrespective of whether or not the contents of the carton completely fill it and such sealing being effective without appreciable permanent distortion or reshaping of the carton structure.

A further-object of the invention is to provide an economical and eificient apparatus for sealing the top closure flaps of a carton where the entire carton, including the top closure flaps, has been previously coated with a thermoplastic material.

A still further object of the invention is to pro-.

vide an improved apparatus for applying temporary localized pressure against the outside surface of the carton to be top sealed, in such a way as to form an efiective support for the first flaps to be folded down into closing position so that the remaining flaps may be brought down over the first fiapsand then held for a sufiicient period to permit the fiaps to properly adhere under the influence of a thermoplastic or other adhesive coating applied to the flaps.

A further object of the invention is to provide apparatus for contacting the exterior walls of a carton to hold the closure flaps in properly assembled position during drying ofthe adhesive on the flaps, in which the contacting means is caused to resiliently engage the proper points on the carton walls and hold the-closure flaps in place without permanently deforming the carton walls or scratching or otherwise marring the exterior surfaces of such walls.

A still further object of the invention is to provide resilient carton wall engaging devices of the type referred to above which are adjustable so as to permit the accommodation of varying sizes likelihood of the thermoplastic material sticking to the belt.

Other and more specific objects will appear as the description proceeds.

Inthe drawings:

Fig. 1 is a more or less schematic elevational view of a. machine for carrying out the present invention;

Fig. 2 is a series of perspective views of the carton together with certain fragmentary parts of apparatus, illustrating the sequence of steps through which the carton is carried to completely seal it;

Fig. 3 is an enlarged plan view of a portion of the apparatus illustrated in Fig. 1, such view being taken along line 3-3 of Fig. 4;

Fig. 4 is an enlarged side elevational view of the apparatus illustrated in Fig. 3, taken along line 4-4 of such latter figure;

Fig. 5 is a sectional view taken along line 5-5 of- Fig. 4, looking in the direction of the arrows;

Fig. 6 is a fragmentary detail view showing a carton and'presser mechanism for exerting pres-,

sure upon the upper portions of the carton;

Fig. 7 is a fragmentary sectional view taken on line 1-1 of Fig. 6, looking in the direction of the arrows, illustrating, in a somewhat exaggerated manner the method of exerting temporary pressure on the carton to keep the inner closure flaps in position against the lower surface of one of the overlying closure flaps.

Fig. 8 is a view in elevation, certain parts being shown in section, of a modified form of apparatus for exerting pressure on the upper portions of the cartons to retain the downfolded underlying closure flaps in proper closure forming position; and

. Fig. 9 is a horizontal sectional view of the same flaps of regularly formed folded cartons after I they have been filled with a desired commodity.

- A principal feature of the invention is to overcome certain disadvantages that have existed in the machines heretofore employed due to the fact that the usual narrow underlying flaps projecting from the edge or narrow walls of the carton are not properly secured to the bottom surface of the overlying flap or flaps, particularly when the commodity introduced into the carton to be sealed does not completely fill it. According to the present invention an apparatus is provided for more or less positively maintaining the underlying end wall underlying fiaps against downward movement into the carton even though the commodity packed in the carton is not suflicient to fill it entirely to the top, this being done without permanently distorting or marring the carton. 7

Referring more particularly to the drawings, there is disclosed a filling and sealing machine designated as a whole at II, which comprises a suitable frame H, capable of being bolted to the floor or other supporting surface. The frame ll comprises spaced frame elements l2, l2, arranged to support the various parts of the machine.

As disclosed herein, the cartons l3, I3, which have been previously set up and closed at one end by means not shown are placed on a suitable conveying means herein illustrated as an endless belt conveyor, and the cartons are carried by this conveying means to a filling station, generally indicated at I5, then past a station l6 for bending inwardly the fiaps located on the end walls of the carton, then past a station l1 for successively folding in the-wide flaps located on the side walls of the carton. The cartons are then moved so as to come in to engagement with a side wall pressing means, indicated as a whole at l8 and, lastly, the cartons are moved into operative relation with a suitable device, indicated at IQ for applying and maintaining downward pressure upon the overlapping top fiaps of the carton.

' As previously indicated the conveying element I4 is preferably in form of a suitable endless belt type of conveyor although other conventional forms of conveying means could be employed with equal facility. In the present instance the conveyor belt 22, formed of canvas or other flexible material, is supported at its ends on an idler roll 23 and a driven roll 24 suitably mounted on the frame II. For the sake of simplicity only the roll 26 is shown in detail.

Theroll 24 is suitably keyed to a drive shaft 25 which may be connected to any suitable source of power, such as an electric motor. The drive shaft 25 is suitably journaled on the frame elements l2, 12. A supporting plate 21, secured to the frame l2, I2, is provided for supporting the belt 22 between the rolls 23 and 24.

The belt 22 is preferably provided with suitable cleats or spacing elements indicated at 28, 28, for properly registering the cartons on the conveyor belt and guiding elements, indicated at 29, 29 for maintaining the cartons properly centered on the belt.

The cartons l3 are first set up and have the bottom flaps suitably sealed, as by means of ordinary glue or similar adhesive. They are then deposited upon the conveyor by any conventional means, or by hand if desired. The conveying means l4 carries the carton to the filling station l5 which may be suitably controlled so as to automatically deposit a measured quantity of commodity into the carton.

The cartons may have the top flaps sealed by adhesive in the same manner as the bottom flaps. The present machine, however, is designed particularly for handling cartons which have been submerged in a hot thermoplastic substance so as to apply a coating of such thermoplastic substance substantially uniformly over both inner and outer surfaces of the carton walls as well as the bottom and top closure flaps.

The cartons l3, l3, after having been sealed at the bottom, coated with thermoplastic, and

suitably filled, as previously stated, next pass to the station 16 where a folding element 32, automatically controlled to operate in synchronism with the movement of the carton on the conveyor by conventional means not shown, depresses the rear edge wall flap so as to cause it to assume a position substantially in the plane of the upper edges of the carton walls. The forwardly disposed edge wall flap 34 is depressed into a similar position by means of a suitably formed shoe element 35 having a curved face 36. The side faces 31., 31, of the shoe 35 are arranged to contact the inner surfaces of the side wall flaps 38 and 39 of the carton. In the present instance the side faces 31, 31 are inclined to each other in an upwardly diverging manner so as to cause firmer contact of the side wall flaps against such sides.

The shoe 35 is preferably heated by suitable electric heating units, not shown, so that when the flaps come in contact with the 51100. the thermoplastic coating thereon will be rendered soft and tacky.

After the carton passes out from beneath the shoe 35 it is acted on by the parts of station 11 which includes two properly curved stationary cam elements 40 and 4|. The cam element 40 is arranged to engage and downwardly fold the side flap 38 and the cam element 4| is arranged to downwardly fold the side flap 39. The cam elements 40 and 4| are secured in any suitable way as by bolting same to a portion of the frame, as indicated at 42.

As the cartons continue to pass along on the conveying means l4, they are acted upon by the side wall pressing means l8 which will now be described.

The side wall pressing means, as herein disclosed preferably comprises a pair of endless' the sprocket 46, a bevel gear 52 is keyed to the so as to contact'the side walls of the carton" slightly below the place of the inner, downfolded, top closure fiaps 33 and 34, see Fig. '7. In the present instance the presser plates 51 are so designed and controlled as to engage only the central portion of the side walls, as best seen in Fig. 6. It is to be understood that the driving gears for the chain elements 44, 45 are so designed as to move the chain in exact synchronism with the movement of the belt 22 which carries the carton and the links 56 are so placed as to contact the central portion of the side walls of the carton when properly held between the spacer members 28, 28. For the purpose of supporting the inner run of the presser chains 44 aeeaoos and 45 there are provided guiding elements 66 and 59, in the form of vertically disposed plates against the surface of which the rear sides of the links. particularly the presser plates 51 on the links are adapted to engage. Inwardly directed parts 60 and 6| are provided to serve as the downfolded flaps of the cartons will now be described. Referring to Figs. 3, 4 and 5, this closure flap pressure mechanism comprises a belt 63 supported at one end over an idler roll 64 and at the other end on a driven roll 65. For the purpose of driving the roll 65 the shaft 66 on which it is mounted carries a bevel gear 61 which meshes with a bevel gear 68 on the shaft 49 carrying the driven sprocket 46.

The end of the belt 63 first coming into contact with the top of the carton I3 is so designed as to begin to apply pressure to the tops of the cartons immediately after the presser plates 51 of the side wall presser chains have come into play to slightly deflect inwardly the side walls of the carton. This relationship of parts is best illustrated in Figs. 3 and 4.

Means are preferably provided for maintaining a yieldingpressure on the top of the closed cartons and for this purpose a plurality of elongated openings 69, 69 are provided in the vertically extending plates 58 and in these openings are received the spindle ends of a plurality of rollers, indicated at III, III; As the cartons pass along beneath the top presser belt 63, the weight of the belt and of the rollers immediately above the carton will be imposed upon the downfolded and overlapping fiaps. This weight will be of a yielding nature and thus prevent an undue amount of pressure from being exerted upon the top of the cartons.

For the purpose of preventing sticking of the hot thermoplastic coating on the carton flaps to the top presser belt, the belt is preferably kept moist by applying suitable quantities of water to it from time to time asneeded.

The sequence of operation of the machine of the present invention upon cartons is clearly indicated in Fig. 2. The carton indicated at A, has just been filled and the closure flaps are still in an upstanding condition. At 13, the end wall flaps are partially turned in due to the action of the element 32 and the heating shoe 31. At 0, the heating shoe 31 is shown in position in which heat is being applied to the flaps 33 and 34 as well as to the inner faces of the flaps 38 and 39. At D the flap 38 has been folded substantially its lowermost position, the fiaps 39 remaining in its origina1 standing position. At E, the side wall fiaps are shown insubstantially their final position. At F, the carton is shown in a closed position and is just beginning its passage under the downward pressure-applying belt 63.

When the completely sealed carton reaches the end of the machine it can be removed by any conventional, well-known means or by hand.

The modified form of the invention illustrated in Figs. 8 and 9 differs from the form illustrated in Figs. 1 to 7, inclusive, in that the pressure means for applying deflecting pressure to the upper edges of the side walls of the cartons is provided by an oppositely disposed pair of endless pressure elements, such as' relatively narrow, flexible belts, it being unnecessary for this form of pressure mechanism to be definitely synchronized with the remainder of the sealing machine for the reason that continuous pressing surfaces are provided. I

Referring particularly to Fig. 8, there is pro vided a base frame III, similar to frame H,

comprising spaced frame elements H2, H2 for supporting the operating parts ofthe machine. The cartons I I3, identical with cartons I3, are supported on a conveyor H4, designed to convey the cartons from the filling'and closing stations,

not shown in this modified form, but which may be identical with similar parts in the form shown in Fig. 1. In addition to the belt conveyor H4 the present modified form of the invention includes a side wall pressing means designated generally at H8 and a top pressing device indi- V oated as a whole at H9.

The conveyor H4 is of the endless belt type having a belt designated at I22 supported at one end on a driven roll I24 and at its other end by a similar roll not shown which can be an idler roll, as indicated at 23 in Fig. 1. The roll I24 is keyed to a drive shaft I25 connected to a source of power, and suitably joumalled on the frame elements H2, H2. A supporting plate I21, secured to frame I I2, I I2, supports the upper run of belt I22.

As in the case of belt 22, the belt I22 is preferably, although not necessarily, provided with spacing and guiding elements I28 and I29.

After the carton H3 is given a suitable adhesive treatment and the flaps closed, as by means of the devices illustrated in Fig. 1, it is then delivered to the side wall presser device H8 which will now be described in detail. This 'device I I8 in this modified form of the invention preferably comprises two identical endless belt elements. I44 and I45. For simplicity only the element I44 will be described in detail.

The presser element I44 comprises essentially a belt I46 passing over a sheave I41, so positioned as to bring the belt into contact with the carton H3 at a point just below its upper edge as best seen in Fig. 8. For the purpose of driving the sheave I41 it is keyed to a vertical shaft I49 carriedby a bearing I56 which is in turn carried by arms I5I, projecting from one of the frame members H2. A bevel gear I52 is keyed to the shaft I43 and meshes with a bevel gear I53 keyedto the driven shaft I25.

The belt I46 is preferably round in cross section and may be formed of any suitable relatively flexible material such as rubber, leather or woven cord.

The arrangement is such that when the closed cartons I I3 are brought in between the two belts I46, I46 initial light pressure will be applied to the carton side walls at points substantially in line with the axes of the sheaves I41, I41.

Means are provided for applying a. somewhat increased pressure on the carton side walls when the advancing edge of the carton'clears the area lying between the contours of the sheaves I41, I41. For this purpose there are-provided two opposing series of pressure applying rolls I55, I55 yieldingly mounted on the frame of the machine and bearing against the outer sides of the two belts I46, I46. In the present instance the rolls I55 are secured in individual yokes I56. Each yoke being suitably formed or secured on the end of a rod I51 slida'ble in a guide block I58 which is exteriorly threaded so as to be adjustably associated with frame plate I59 provided with interiorly threaded openings. A suitable coil spring I60 is provided bearing at one end against the yoke I56 and at the other end against the guide block I58 thus producing a thrust to the yoke and forcing the roll I55 against the belt I46. The guide block I58 is preferably provided with an end portion I6| which is hexagonal in shape so as to adapt it to be rotated by a wrench when it is desired to increase or decrease the tension on the spring I60. In order to prevent rotational movement of the yokes I56, each yoke is slidably fitted into an opening 156a.

formed in the frame element II2.

It is thus seen that the belts I46, I46 will engage the side walls of the carton H3 and deflect such walls inwardly at points located just below the plane of the closing position of the inner closure fiaps to apply pressure on the edges of these flaps and retain them in position to insure that they will properly adhere to the overlying closure flaps as explained in connection with the first illustrated form of the invention. In the presently described form it is not necessary to operate the side presser mechanism in synchronism with the remainder of the device which was done in. the first form so as to keep the presser mechanism from exerting pressure on the comers of the cartons which would tend to deform them permanently and render them unsightly. The belt I46 is arranged to be urged toward the cartons with such moderate pressure as to properly deflect the mid portions of the side walls inwardly but at the same time not to be suflicient to cause any bending or deformation of the cartons at their corners.

The mechanism 9 for applying downward pressure on the tops of the cartons comprises a belt I63 supported at its one end over a driven roll I65 and at its other end over a suitable idler roll not shown. The roll I65 is keyed to a shaft I66 carrying a bevel gear I61 meshing with a bevel gear I68 on the shaft I49 which carries the sheave I41.

The belt I63 is so related to the remainder of the device that it will begin to apply top pressure on the cartons immediately after the side walls of the carton have been fully deflected inwardly. For the purpose of applying top pressure a series of rollers, one of which is indicated at I10, is provided having reduced spindle ends "I fitting within vertically elongated openings in the frame of the machine similar to the arrangement described in connection with the first form of the invention.

The roll I10, illustrated in Fig. 8, is the first roll of a series, and it will be understood that the remaining rolls arranged with this form of machine wil be dsitributed rearwardly of the belt I63, this being the direction of its travel, similar to the arrangement illustrated in Figs; 3 and 4. The first roll I10 is preferably located somewhat rearwardly of the first pair of oppositely disposed rolls I55 so that inward deflecting pressure will be exerted by the first pair of rolls I55 prior to the time of increased down pressure being exerted on the closures of the cartons.

Summarizing the advantages of this form of support to prevent them from being displaced downwardly due to the application of downward pressure upon the overlying closure flaps while the adhesive between the overlapping flaps is in the process of becoming set.

The pressure exerted by the belts I46 on the carton side walls can be readily varied by ad-' justing the guide blocks I6I. These guide blocks may, of course, be adjusted independently of each other so that, if desired, the pressure exerted on the carton side walls may be either progressively increased or decreased throughout substantially the length of the belt I46. If desired, the pressure exerted by the individual rolls I55 can be varied to produce at first a relatively light pressure, becoming progressively increased in intensity until the mid portion of the belt I46 is reached, and then the pressure can be so adjusted as to become progressively lighter for the remainder of the travel of the carton in conjunction with the belts I46.

The inward deflection of the side walls produced by the side wall presser devices has the additional advantage, particularly in the case of packing frozen foods, of excluding a portion of the air contained in the carton thus reducin oxidation effects. If the food product introduced into the carton is to be frozen subsequent 1y to its introduction, as in the case of nonfiuent foods, such as broccoli and spinach, the inward deflection of the side walls just prior to final sealing causes the exhaustion of a portion of the air within the carton and, since the deflection of the side walls is maintained until after sealing is complete, the walls will tend to stay in their inwardly deflected condition due to the fact that invention, it is to be understood that the lateral the carton is hermetically sealed. Then, upon freezing of the contents, with consequent expansion thereof, this expansion will be readily permitted by the side walls which will thereon tend to regain their original undeflected condition.

In the case of food products which have been previously frozen-and are in a more or less fluent condition, such as peas and shelled beans, the inward deflection of the side walls of the carton containing such products will express a portion of the air contained in the carton and the carton will be sealed in such partially exhausted condition. This will have the effect of reducing the amount of oxygen contained within the carton and will correspondingly lessen the tendency of oxidation eifects within the carton. Since the pressure on the side walls is exerted adjacent their upper edges there will be produced little or no disturbing effect upon the body of the food product within the carton.

From the foregoing it is apparent that the present invention provides a simple and effective means for maintaining the inner top closure fiaps in a position substantially in alignment with the plane of' the upper edges of the side and end walls whereby, upon subsequent pressure being exerted and maintained, the overlying flaps will be fir'mly adhered to the underlying flaps thus obtaining a seal of maximum efiiciency for the top of the carton.

It is also to be understood that the present invention is not limited to use with cartons the tops of which have been coated with a thermoplastic material as the invention is equally applicable to the sealing of cartons by means of liquid adhesive, not thermoplastic in character and quite satisfactory for effectively securing the flaps in close contact, particularly in cases where no complete hermeticseal of the carton is required, this being in the case of cartons for retaining comminuted materials which have a tendency to sift and therefore require a tight seal to prevent such sifting; a

A particular advantage which the machine of the present invention presents when employed with cartons being coated with a thermoplastic material is that when the thermoplastic coating material is subjected to disruptive action due to bending of the flaps into the closure position, the heating shoe will engage these areas where fracture is likely to or does develop and will replasticize the thermoplastic over these areas or lines whereby as soon as the flaps are brought to a lowered or closure forming position the thermoplastic will be caused or allowed to form a complete film along these areas or lines when the thermoplastic cools. This advantage is not obtained in the case of liquid adhesives which are not thermoplastic, as, in the ordinary case, the adhesive is not spread on the flaps so as to cover the score lines between the flaps and side and end walls of the carton and thus even if the carton is coated with thermoplastic material and liquid adhesive is employed-without the application of heat, there is likely to be some leaking'at the score lines due to disruption of the thermoplastic fllm. along the score upon bending of the flaps along such lines.

- While the present description sets forth a preferred embodiment of the invention, numerous changes may be made in the method and the construction without deviating from the spirit of the invention, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being bad to the appended claims rather than to the foregoing description to indicate the scope of the invention.

We claim: 1. In apparatus for sealing the top flaps of cartons having two parallel side walls disposed on opposite sides thereof, the improvement comprising, in combination, means for conveying said cartons in upright position, a pair of flexible elements in position to contact the upper edge p'ortions of said side walls of said cartons on said conveying means, means for moving said flexible elements at the same rate and in the same direction as said conveying means, means for applying pressure to the outer sides of said flexible elements to effect a slight inward deflection of the upper portions of said side walls, whereby downward movement of said top flaps past their normal closed position when pressure is applied thereto is prevented, and means for applying and maintaining pressure on the tops of said cartons during movement of said cartons by said conveying means.

2. In apparatus for sealing rectangular cartons having top closure flaps, the improvement comprising, in combination, means for conveying said cartons in upright position with said top flaps provided with adhesive and in closed position, a pair of flexible belts arranged to contact the upper edge portions of oppositely disposed side walls of said cartons on said conveying means, means for moving said flexible belts at the same rate and in the same direction assaid conveying means, pressure-applying rolls urged by resilient means bearing against the outer sides of said belts to effect a slight inward deflection of the upper portions of said side walls, whereby said upper portions firmly engage the edges of the lowermost of said top closure flaps to prevent downward movement thereof'when pressure is applied to-the tops of said cartons, and means for applying and maintaining pressure on the tops of said cartons during movement thereof until said adhesive has become set.

- resiliency of said resilient means.

ROY E. LOWEY. EDGERTON A. THROCKMORTON.

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