US3555975A

US3555975A - Apparatus and method for automatically forming and sealing pliable containers

Info

Publication number: US3555975A
Application number: US710238A
Authority: US
Inventors: Bernard C Barnes
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-03-04
Filing date: 1968-03-04
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19

Abstract

This invention relates to a simple apparatus and method for automatically sealing pliable containers, particularly plasticcoated paper-base containers, by consecutively partially prefolding inwardly at least one end of the container by use of movable folding means comprised of converging crimping and spanking elements and sealing at least one of said crimped ends by compressing said end between a movable anvil and a stationary sealing head, the latter having a face comprised of a pressure land and a plurality of elevated sealing ribs superimposed thereon so as to apply a uniform sealing force to predetermined positions in the interior of the container end while simultaneously applying a continuous pressure to the interior folds of said container end. The sealing head also provides a means for uniformly and positively aligning the container thereon.

Description

United States Patent [72] inventor Bernard C. Barnes 3643 N. Durfee Road, Apt. C, El Monte,

Calif.

[21] AppL NO. 710,238

[22] Filed Mar. 4, 1968 [45] Patented Jan. 19, 1971 54 APPARATUS AND METHOD FOR AUTOMATICALLY FORMING AND SEALING PLIABLE CONTAINERS 22 Claims, 18 Drawing Figs.

[52] US. Cl 93/44.1 53/375193/59 [51] Int. Cl B3lb 1/02 [50] Field of Search ..93/44.1, 36, 59; 53/375 [56] References Cited UNITED STATES PATENTS 3,196,760 7/1965 Terry 93/44.1

3,248,841 k 5/1966 Heffelfinger et al. 3,422,730 l/1969 Mitzelfelt et al Primary ExaminerBernard Stickncy Att0rney Roman A. Dimeo ABSTRACT: This invention relates to a simple apparatus and' method for automatically sealing pliable containers, particularly plastic-coated paper-base containers, by consecutively partially prefolding inwardly at least one end of the container by use of movable folding means comprised of converging crimping and spanking elements and sealing at least one of said crimped ends by compressing said end between a movable anvil and a stationary sealing head, the latter having a face comprised of a pressure land and a plurality of elevated sealing ribs superimposed thereon so as to apply a uniform sealing force to predetermined positions in the interior of the container end while simultaneously applying a continuous pressure to the interior folds of said container end. The sealing head also provides a means for uniformly and positively aligning the container thereon.

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INVENTOR. BEEN/460 C- EAEMFS ,4 TTOEA/EV APPARATUS AND METHOD FOR AUTOMATICALLY FORMING ANDSEALING PLIABLE CONTAINERS This invention relates toan apparatus and method for'automatically forming and sealing pliable containers, and more particularly, anapparatus and method for automatically forming and sealing pliable containers having at least the surface thereof comprised of a plastic substance capable of producing ten-the plastic or plastic-coated end thereof into an adhesive 7 condition, applying an external force" to the partially folded end thereby completingthe folding thereof, and-causing the subsequent sealing of the folds by thecompression of the heatedfolds together against the stationary anvil; The external force is normally applied. to the containerend by a sealing means axially movable relative to the container and which has the face thereof provided with'a plurality of preset pressure points of substantially uniform height.

Apparatuses currently in use for forming and sealing the above containers are. large,.cumbersomei and 'eirpensive to manufactureand maintain. in addition, as hereinabove indicated, the existing apparatuses capable of performing the aforesaid functions apply a force atpreselected points externally across the .folds of the container end. That is,the sealing contact points carried bythe movable sealing means are moved into contact with the folds of the container end on the outer. side thereof at preselected points while the opposing abutment headoranvil is stationary, and positioned on the inner side of the folds.

This arrangementhas a number of inherent detrimental features'; First of all, if the contact points suffer wea'r through repetitive use'(i.e.,icontainer abrasion), or for other reasons (i.e., clutch wear)'fail to move properly into position so as to make complete contact with the folds ofthe container end, inadequate fusion of the plastic on the fold occurs causing an unsatisfactory seal and resulting in seepage or. leakage of the container contents, particularly if liquid,.through the fold.

Further, container end alignment with respect to the sealing points is extremely. critical and important.-A deviation ofthe sealing points of aslittleas one thirty-secondinch'relative to the container end is detrimental since misalignment of the Another advantage of applying the sealing means by a stationary head on the inner side of the folded container end rather than the outer side thereof by a traveling sealing means as heretofore accomplished, is that proper alignment of the sealing means with the container end, and concomitantly the container end folds, is always assured. Thus, the stationary sealing means being always in the same predetermined position, contacts the inner folds of the container end at the same preselected points without the danger of misalignment due to sealing point wear, clutch wear on the traveling head, etc.

'The invention herein also discloses a new and novel means for folding the container ends inwardly prior to the application of heat thereto and the sealing operation. The new and novel folding means, as will be more fully hereinbelow described, is comprised of a movable crimping element having a plurality of crimping blades capable of simultaneously providing a gradual converging force and'a plurality of spaced spanker elements capable of simultaneous movement in planes parallel to each other, but not in the movement plane of the crimping element. Thus, the crimping element provides a convergent force to the extended container end in one plane, while the spanker elements apply an almost simultaneous force to the bend at the juncture of the container end with the container body in planes parallel to the action of the crimping element so as to fold the container end inwardly towards the container axis in a predetermined manner.

Accordingly, it is an object of this invention to provide a simple apparatus for automatically forming and sealing pliable containers.

An additional object is to provide a simple apparatus for au- V tomatically forming and sealing pliable containers which is container end and sealing pointsresultsin the latter failing to being comprised of a pressure. land. Thus, as amovable anvil (which is devoid of sealing contact points) compresses the foldedcontainer endagainst'the stationary sealinghead, the sealing ribs of the stationary sealinghead provide sealing pressures at specific locations on the inner surface of a folded containerend. Simultaneously therewith, the". pressure land applies a continuousforce to the internal folds of the container end so as to maintain the folds intight association during the sealing process. Although a uniplanular pressure land is adequate to perform-this function, a multiplanularpressure land is preferred since the niultiplanular face of the .sealing head conforms to elevational differences of the internal folds of the container end thereby providingmore equalized pressure thereto. Thus, the normal leakage area,.in addition to being dammed i or diked," swages-the material of the container end folds at the pressure locations thereby insuring a positive fusion of the fold and consequently a positive leakproof seal. r

mobile.

'Another object is to provide a simple apparatus for automatically forming the ends of pliable containers which utilizes a spanker means in conjunction with a crimper means.

Still another object is to provide a simple apparatus for automatically forming the ends of a pliable container wherein the crimper means are capable of variable movement in one plane and the spanker means are capable of movement in different planes.

Yet another object is to provide a simple apparatus for automatically forming the ends of a pliable container wherein the crimper and spanker means are capable of being utilized with any size container.

Another object is to provide a simple apparatus for automatically sealing the ends of a pliable container which applies a sealing force to the inner folds of the container end.

Still another object is to provide a simple apparatus for automatically sealing the ends of a pliable container by use of a stationary sealing head provided with a plurality of elevated sealing ribs.

A further object is to provide a simple apparatus for automatically sealing the ends of pliable container which forms a substantially continuous sealing pattern.

Another object is to provide a simple apparatus for automatically sealing the ends of a pliable container which forms an intermittent sealing pattern.

Yet another object is to provide a simple apparatus for automatically sealing the ends of a pliable container which utilizes a sealing head capable of compensating for the various levels of the folded container end.

An additional object is to provide a simple apparatus for automatically forming and sealing the ends of a pliable container which provides a reliable and positive means for insuring proper container alignment.

Another object is to provide a method for automatically forming and sealing the ends of a pliable container.

Still anotherobject is to provide a method for automatically forming the ends of a pliable container by utilizing a spanker means in conjunction with a crimper means.

.Yet another object is to provide a method for automatically sealing the ends of a pliable container by forming an intermittent sealing pattern.

A further object is to provide a method for automatically sealing the ends of a pliable container by forming a substantially continuous sealing patternv Another object is to provide a method for automatically sealing the ends of a pliable container by applying a sealing force to the inner folds of the container end.

An additional object is to provide a method for automatically sealing the ends of a pliable container by use of a stationary sealing head provided with a plurality of elevated seal ing ribs.

Still another object is to provide a method for automatically sealing the ends of a pliable container by utilizing a sealing head capable of compensating for the various levels of the folded container end.

Yet another object is to provide a method for automatically I forming and sealing the ends of a pliable container which provides a reliable and positive means for insuring proper container alignment.

Other objects and advantages of the invention will become apparent from the description taken in conjunction with the following drawings in which:

FIG. 1 is an elevational view of the apparatus of the invention, partly sectioned to show the forming means thereof;

FIG. 2 is a cross-sectional view of the apparatus taken on line 2-2 of FIG. 1;

FIG. 3 is an elevational view partly in section of the forming means of the invention taken on 'line 3-3 of FIG. 2 showing the crimping and spanker means in a preoperative position;

FIG. 4 illustrates the crimping and spanker means of FIG. 3 in an operative position deforming and folding the container end;

FIG. 5 is a top plan view similar to FIG. 2 illustrating the crimper and spanker means in an operative position as shown in FIG. 4;

FIG. 6 is an elevational view of the apparatus of the inven tion partly sectioned so as to show the sealing means of the invention herein;

FIG. 7 is a top plan view of the sealing means illustrated in FIG. 6 taken on line 7-7 thereof;

FIG. 8 is a side elevational view partly in section of the seal ing means illustrated in FIGS. 6 and 7 showing the movable anvil plate pressed against the folded container end so as to force the same against the stationary sealing head;

FIG. 9 is a top plan view ofthe sealing head of the instant invention showing a plurality of substantially continuous sealing ribs and a multiplanular pressure land;

FIG. 10 is a side view in section of the sealing head illus trated in FIG. 9 taken on line 1010 thereof showing the multiplanular elevations of the pressure land;

FIG. 11 is a fragmented side sectional view of the sealing head illustrated in FIG. 9 taken on line 11-11 thereof;

FIG. 12 is the inside bottom of a sealed container showing the folds and sealing impression resulting from the sealing head illustrated in FIG. 9;

FIG. 13 is a top plan view of another embodiment of the sealing head of the invention showing a plurality of rectangular sealing ribs and a uniplanular pressure land;

FIG. 14 is the inside bottom of a sealed container showing the folds and sealing impression resulting from the sealing head illustrated in FIG. 13;

FIG. 15 is a fragmented side sectional view of the sealing head illustrated in FIG. 13 taken on line 15-15:

FIG. 16 is a top plan view of another embodiment of the sealing head of the invention showing a plurality of rectangular and cylindrical sealing ribs and a uniplanular pressure land;

FIG. 17 is the inside bottom of a sealed container showing the folds and sealing impression resulting from the sealing head illustrated in FIG. 16; and

FIG. 18 is a fragmented side sectional view of the sealing head illustrated in FIG. 16 taken on line 18-18.

Referring more particularly to FIGS. l5, reference numeral 20 designates generally a body shell secured to body frame 21. To provide mobility to the apparatus, wheels or casters 22 may be secured to body frame 21. Rotatably secured to body frame 21 by shaft means 23 is mandrel drum 24 having a plurality of mandrel arms 25 radially projecting therefrom. Each mandrel arm 25 is provided with a flange 26 perpendicular to the arm axis which has secured thereto a plurality of crimping fingers 27 divergently upwardly and outwardly curving from the upper face thereof. Each mandrel arm 25 is also provided with a pilot flange 28 which is parallel to and spaced from, flange 26. Sealing head 29 is secured to the extremity of mandrel arm 25 opposite mandrel drum 24. in spaced relationship to pilot flange 28, and also in parallel alignment therewith. It should be noted that the lateral dimension of sealing head 29 and pilot flange 28 are substantially the same so that a container 30 positioned thereon is supported at two spaced locations thereby providing rigidity to the hollow container during the forming and sealing operations.

As best seen in Stage I of the operation (i.e.. the position of the mandrel arm extending vertically upward from the mandrel drum). the sealing head 29 and pilot flange 28 serve to correctly position container 30 thereon so that when said container is forcibly displaced downwardly (as shown by an arrow), only the end 30a thereof contacts the surface of flange 26. During this downward displacement. divergently curved crimping fingers 27 slightly deform the container end 30a inwardly in the same plane causing the opposite sides of end 30a to also buckle inwardly. It should be noted that the end opposite to that which is to be sealed is inserted over sealing head 29 and pilot flange 28 for reasons which will become obvious.

When the container 30 rotates to Stage 2 (as shown by an arrow) by clutch means 31 connected to mandrel drum 24. said clutch means being activated by piston 31a, said container is positioned opposite an elongated crimper arm 33 pivotally secured to frame 21 by pivot means 32. Rotatably secured to crimper arm 33, for convergent and divergent movement in the same plane. are a plurality of

crimper blades

34 and 35.

Crimper blades

34 and 35 have an eccentric cam configuration and are pivotally secured to crimper arm 33 by pivot pins 36 and 37. Spring means, or the like. 38

interconnect crimper blades

34 and 35 to return said crimper blades to their original or preoperative position after they have partially folded container end 30b to the desired degree. It should be noted that the convergent action of

crimper blades

34 and 35 are limited upon the contact of the lead edges thereof with the container portion immediately adjacent the forward corners of the sealing head 29.

Also extending from pivot means 32 and pivotally secured thereto is an elongated spanker arm 39. Secured to spanker arm 39 are a pair of spaced

spanker blades

40 and 41 in sub stantially parallel alignment and having outwardly divergent ends 40a and 41a, respectively. Spanker blade ends 40a and 4111 are moved forward until they contact the external folds of the sides of container end 300 not crimped by

crimper blades

34 and 35 so as to break" the aforesaid external folds. Thus, as the crimper blades begin to convergently fold two opposite sides of container end 30a, ends 400 and 41a of

spanker blades

40 and 41 exert a convergent force on the outer folds of the remaining two sides of container end 30b so as to roll or swage the container end, thereby enhancing the folding operation.

Extending outwardly from said spanker arm 39 is a restraining member 42 provided with a restraining flange 43 project ing laterally therefrom. The purpose of restraining flange 43 is to engage and retract crimper arm 33, an

concomitantly crimper blades

34 and 35 from association with the container end 30b after the foldingfunction is performed. That is, as spanker arm 39 is retracted, flange 43 engages crimper arm 33 and concomitantly retracts the latter with it.

Secured to spanker arm 39 is a crimper blade actuator 44 which is slidably attached to retaining element 45 projecting from arm 39 and is prohibited from disengagement therefrom by flange 46 formed by the ends thereof engaging flange head 47 carried by said retaining element 45. Spring means 48 interposed between the inner side of actuator 44 and flange head 47 maintain the actuator in an extendedposition from said flange head. Upon contact of saidactuator 44 with the cam portions-34a and 35a of crimperblades 34 and35,

respectively, the forward ends of said crimperblades are spring means 38 will contract and separate the ends of

crimper blades

34 and 35.

The aforesaid retraction of spanker arm 39 and subsequently crimper arm 33, after the forming operation, is performed by conventional piston means 49 which is interconnected with spanker arm 39 by piston rod ,50.

Although the crimping blades are described herein as being secured to a piston driven pivoted crimper arm and are activated by a friction.,activator, said crimper blades may be mounted on vertically or horizontally traveling arm which is gear driven and the crimper blades may be activated by gear means without deviating from the scope of the invention disclosed herein. a v I j i i if it is desiredto "break the folds of the sides of container end 30a other than the sides partially crimped by crimping fingers 27, a plurality of

conventional pistons

51 and 52 provided with biplanular piston heads 53 and'54, respectively, may be utilized to fold the aforesaid sidesv of container end 30a over the opposite edges of pilot flange 28. i

it should be noted that similar piston means may be positioned in the same mariner opposite the forward edges of sealing head 29 and synchronized with the crimping operation of

crimper blades

34 and 35 so as tobreal the opposite sides of container end 30b in lieu of utilizing

spanker blades

40 and 41 without deviating fromthe scope of the invention herein.

After the forming operation, container 30, by virtue of clutch means 31 connected to mandrel drum 24. as aforesaid,

is rotated to Stage 3 where heat is applied by heating means 55. Although any conventional heating means may be employed provided sufficient heat is generated to impart an adhesive condition to the plasticmaterial about theexterior of the container and a satisfactory .heat activation" (heat affected) area is obtained, to simplify and enhance the mobility of the apparatus. electrical heating means are preferred so that a single conduit to the apparatus is required, eg an electric cord.

As best seen in FIG; 6, after container end 30b is sufficiently heated, the container is rotated to Stage 4. Prior to arriving at State 4, however, container end Bob-passes through folding guide means 56 which substantially complete the folding operation of the container end 30b so that the latter is in position to be sealed. (See P10. 7).

Once at Stage 4, anvil 57, which is'connected to piston means 58 by piston arm 59, is motivated forward so as to compress the folded container end 30b against sealing head 29. (See H0. 8). Anvil 57. being pivotally secured to piston arm 59 by pivot means60 easily adjusts to any minor deviations from a true normal plane of the completely folded container end. To eliminate the heat absorbed at the anvil face due to the repetitive contact thereof with heated container ends, a suitable coolant such as water or' air may be circulated through the anvil body.

FIGS. 9 though 11 more clearly reveal the detail of sealing head 29. The face of said head is comprised of a multilevelled pressure land having different elevations 61 and 62, respectively. These elevations, designated by dimensions A and B, respectively, in FIG. 10, are of predetermined heights to compensate for the varying elevations existing on the interior of the container (folded end 30b) due' to the folded material present at the container end;'Specifically, in H6. 12, which illustrates the bottom interior of container 30 Le container end 30b, planes 61 and 62 of the pressure land would accommodate and contact folds 61a and 62a, respectively, thereof Since the sealing means in the instant invention is appliedto the interior of the folded container end, this feature is important in that the sealing force is moreuniform throughout'thc container end. At opposite edges of sealing head 29 are a pair of substantially continuous elevated sealing ribs 63. Normal thereto, arid superimposed upon plane 61 of the pressure land is anotl ier elevated sealing rib 64. Positioned, at least in part, at the intersection of planes 61 and 62 is a fourth sealing rib 65 whicfrlis substantially perpendicular to scaling rib 64, but formsaan angle at one of its extremities to follow the contour of the aforesaid'intersection of planes 61 and 62. Sealing ribs 63,..64 and 65 are of uniform elevation and equal in height (designated bydimension C in FIGS; 10 and 11). It should-be understood that although substantially continuous sealing ribs are illustrated, said ribs may be intermittently interrupted to provide a series of smaller ribs extending in the same pattern without deviating from the scope ofthe invention herein.

As best seen in FIG. 12, sealing ribs 63, 64 and 65 provide a sealing pattern 63a, 64a and 65a, respectively, in the interior of the folded end 30b of the container. The sealing patterns are positioned at critical points in the folds where leakage is sealing head. As hereinbefore indicated. the alignment off the container end'with the sealing ribs is extremely critical andimportant to effect a positive seal since evena minor deviation is detrimental to achieving the same.

Although substantially continuous and intermittent sealing ribs extending coextensively with the inner container folds have been described hereinabove, it should be noted that a plurality of intermittent ribs extending across the inner container folds as shown in FlGS. 13 through 18 may be utilized without deviating from the scope of the invention. Also, as shown in said FIGS. 13 through 18, without deviating from the principles of the invention a uniplanular pressure land may be used. in the alternate embodiment of F165. 13 through 15, sealing head 68 is provided with a pair of substantially continuous elevated sealing ribs 69 at opposite ends thereof and a plurality of intermittent sealing ribs 70 which extend across'the seams of the inner folds 71a of container end 71 in a prearranged manner to contact the most critical sealing points. Said sealing ribs 69 are elevated from, and superimposed on uniplanular pressure land 72. As best illustrated in H6. 14, sealing

ribs

69 and 70 provide a sealing pattern 69a and 70a,

respectively. on the inner folds 71a. Fold 73a is accom- FIGS. 16 through 18. As shown, sealing head 74 is also provided with a pair of substantially continuous elevated sealing ribs 75 positioned at opposite ends thereof and a plurality of intermittent rectangular sealing ribs 76 and cylindrical sealing ribs 77 extending across the seamsof the inner folds 78a of container end 78. As was the case with the embodiment of F105. 13 through 15, sealing

ribs

76 and 77 are in a prearranged pattern so asto contact the most critical sealing points on the inner folds 78a. Sealing head 74 is also provided with a uniplanular pressure land 79. As shown in FIG. 17, sealing head 74 provides a

sealing pattern

75a, 76a and 77a,respectively, on inner folds 78a of container end 78. Again, fold 80a is accommodated in guide notch 80 provided by sealing head 74.

It should be noted that the heights of the sealing heads 68 and 75 are all uniform and equal the height of sealing ribs 63, 64 and 65 of sealing head 29. Further, uniplanular pressure lands 72 and 79 of sealing heads 68 and 74. respectively. are

of uniform height and are equal to the height of pressure land 61 of scaling head 29 so as-to accommodate the thickest pot tion of the inner folds of the container end.

While several embodiments of the invention and methods for using same have been described, it is understood that the particular embodiments of the invention and methods herein discussed are for illustrative purposesonly and that various changes may be made therein without departing from the principles of the invention or the scope of the annexed claims.

lclaim:

I. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, comprising:

a body frame;

a mandrel drum rotatably secured to said body frame;

a plurality of mandrel arms radially projecting from said mandrel drum;

a pilot flange extending outwardly from each of said mandrel arm. said pilot flange situated in a plane normal to the axis of the mandrel arm.

sealing head secured to the extremity of each of said mandrel arm for applying an internal sealing pressure to the folds of a folded container end. said sealing means having at least the face thereof in a plane substantially parallel to the plane of said pilot flange and axially spaced therefrom, said sealing head having a pressure land situated on the face thereof comprised ofa plurality of planes each having different elevations and sealing ribs superimposed upon said pressure land and slightly projecting therefrom;

forming means movably secured to said body frame for folding the end ofa container. said forming means being positioned opposite at least one of said sealing means. said forming means having spankcr means operable in preset planes and crimper means operable in a different plane. said spankcr means comprised of a pair of juxtapositioned impact blades attached to an arm pivotally secured to the body frame so as to be simultaneously movable on both sides of the crimper means, said blades having outwardly divergcntly flaring ends which compress the container at the break line against the corner of the sealing head thereby facilitating the folding of the container end at that juncture and wherein said crimper means is comprised of a pair of blades having an eccentric cam configuration rotatably mounted in the same plane on a movable elongated arm pivotally secured to said body frame;

means for activating said crimping means;

means for activating said spankcr means;

means for heating the plastic-coated container surface to an adhesive condition, said means being positioned opposite at least another of said sealing means;

anvil means, the operative face thereof lying in one plane.

movably secured to said body frame positioned opposite still another of said sealing means for compressing the folded end against said sealing means;

means for activating said anvil means; and

means for rotating said mandrel drum.

2. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are situated in a predetermined manner and are of uniform height.

3. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are elongated and substantially continuous so as to be coextensively positioned relative to the inner seams ofthe folds of a container end.

4. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 3 wherein said sealing ribs are intermittent and in spaced relationship.

5. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are a plurality of elongated rectangular spaced ribs positioned so as to extend across the inner seams of the folds of a container end.

6. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are a plurality ofspaeed elongated rectangular and cylindrical ribs positioned so as to extend across the inner seams of the folds of a container end.

7. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 2 wherein said sealing means is provided with means for aligning a container inserted thereon. said aligning means comprising a notch situated on the periphery of the sealing head and extending through the thickness thereof.

8. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim I wherein said means for sequentially activating said forming means and said spankcr means are pistons and wherein the means for activating said crimper means is a movable friction contact head which engages the rearward ends of the crimper means.

9. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface from the interior thereof. sealing means. comprising:

a sealing head. said head being provided with a sealing face;

a pressure land situated on said sealing face comprised of a plurality ofplanes. each having different elevations; and

a plurality of sealing ribs superimposed on said pressure land and slightly projecting therefrom.

10. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. sealing means as described in claim 9 wherein said sealing ribs are situated in a predetermined manner and are of uniform height.

11. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. sealing means as described in claim 9 wherein said sealing ribs are elongated and substantially continuous so as to be coextensively positioned relative to the inner seams of the folds of a container end.

12. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. sealing means as describe in claim 11 wherein said sealing ribs are intermittent and in spaced relationship.

13. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as described in claim 9 wherein said sealing ribs are a plurality of elongated rectangular spaced ribs positioned so as to extend across the inner seams of the folds of a container end.

14. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. sealing means as described in claim 9 wherein said sealing ribs are a plurality of spaced elongated rectangular and cylindrical ribs positioned so as to extend across the inner seams of the folds of a container end. 7

15. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. sealing means as described in claim 10 wherein said sealing head is provided with means for aligning a container inserted thereon, said aligning means comprising a notch situated on the periphery of the sealing head and extending through the thickness thereof.

16. in an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface. forming means, comprising:

spanker means operable in preset planes. said spankcr means comprised of a pair of juxtapositioned impact blades attached to an arm pivotally secured to the body frame so as to be simultaneously movable on both sides of the crimper means, said blades having outwardly divergently flaring ends which compress the container at the break line against the corner of the sealing head thereby facilitating the folding of the container end at that juncture;and

crimper means operable in plane different from said spanker means. said crimper means comprised of a pair of blades having an eccentric cam configuration rotatably mounted in the same plane on a movable elongated arm pivotally secured to said body frame. 17. A method of automatically forming and sealing pliable containers having a plastic-coated surface, comprising the steps of: l

positioning a containerto be formed and sealed over a pilot flange and a stationary sealing head which are in spatial and parallel alignment with eachother so that the multilevelled pressure land and intermittently continuous sealing ribs carried by the face of said sealing head are in a predetermined-position relative to said container. and the end thereof which is to be formed and sealed is uppermost; convergingly rotating a pair of crimper blades in the same plane thereby inwardly folding the opposite sides of the container end together so as to cause the other sides thereof to buckleinwardly;

while said crimperblade's remain in their convergent position in engagement with saidcontainer end, pressing a pair of spanker blades against the bend of the buckled portion of the container end thereby swaging the container material located at said bend and folding said buckled portion;

heating said folded container end from an external heat source until the plastic coating thereof has acquired an adhesive condition;

pressing a movable abutment anvil theface of which lies in one plane against the heated folded container end thereby compressing said end between the anvil face and the face of the stationary sealing head so that the internal folds of the folded container end are accommodated by the various elevations of the multilevelled pressure land and the intermittently continuous sealing ribs impress a predetermined sealing pattern upon said internal folds of the folded container end;

maintaining said anvil pressure untilfusion of the folds of the folded container end occurs; and

removing said container from said pilot flange and said sealing head.

[8. A method of automatically forming and sealing pliable containers having a plastic-coated surface, comprising the steps of:

positioning a container to be formed and sealed over a pilot flange and a stationary sealing head so that one end thereof is uppermost;

inwardly folding the opposite sides of said container end by a converging force until the remainder'of the sides of said container end buckle inwardly;

prior to the release of said converging force, applying a pressure to the bend of the buckled portion of the container end in parallel planes on both sides of the plane in which the converging force is applied and extending normally to the plane of the converging force;

heating said folded container end until the plastic coating thereofis in an adhesive condition; compressing said heated end against the stationary sealing head so that a predetermined sealing pattern is impressed upon the internal folds of the folded container end; and

removing said container from said pilot flange and stationary sealing head.

19. A method of automatically forming and scaling pliable containers having a plastic-coated surface, as described in claim 17 wherein the positioning of the container on the pilot flange and stationary sealing head is accomplished by aligning the side seam of the container with a notch located on the periphery ofthe scaling head.

20. A method of automatically forming and sealing pliable containers having a plastic-coated surface. as described in claim 18 which includes the step of passing the heated folded container end through a guide folder prior to scaling the end so that the heated container end is further folded thereby facilitating the subsequent sealin o eration.

21. A method for automatica y orming pliable containers having a plastic-coated surface, comprising the steps of:

inwardly folding the opposite sides of said container end by a converging force until the remainder of the sides of said container end buckle inwardly; and

prior to the release of said converging force applying a pressure to the bend of the buckled portion of the container end in parallel planes on both sides of the plane in which the converging force is applied and extending nor mally to the plane of the converging force.

22. A method for automatically sealing pliable containers having a plastic-coated surface and mounted on a pilot flange and stationary sealing head having a face comprised of multilevelled pressure land and intermittently continuous sealing ribs carried by said sealing head face comprising the steps of:

heating the folded end of said container end until the plastic coating thereof is in an adhesive condition;

compressing said heated end between a movable abutment anvil the face of which lies in one plane and the face of said sealing head so that the internal folds of the folded container end are accommodated by the various elevations of the multilevelled pressure land and the intermittently continuous sealing ribs impress a predetermined continuous sealing pattern upon said internal folds of the folded container end; and

maintaining said anvil pressure until fusion of the folds of the folded container end occurs.

Claims

1. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, comprising: a body frame; a mandrel drum rotatably secured to said body frame; a plurality of mandrel arms radially projecting from said mandrel drum; a pilot flange extending outwardly from each of said mandrel arm, said pilot flange situated in a plane normal to the axis of the mandrel arm; sealing head secured to the extremity of each of said mandrel arm for applying an internal sealing pressure to the folds of a folded container end, said sealing means having at least the face thereof in a plane substantially parallel to the plane of said pilot flange and axially spaced therefrom, said sealing head having a pressure land situatEd on the face thereof comprised of a plurality of planes each having different elevations and sealing ribs superimposed upon said pressure land and slightly projecting therefrom; forming means movably secured to said body frame for folding the end of a container, said forming means being positioned opposite at least one of said sealing means, said forming means having spanker means operable in preset planes and crimper means operable in a different plane, said spanker means comprised of a pair of juxtapositioned impact blades attached to an arm pivotally secured to the body frame so as to be simultaneously movable on both sides of the crimper means, said blades having outwardly divergently flaring ends which compress the container at the break line against the corner of the sealing head thereby facilitating the folding of the container end at that juncture and wherein said crimper means is comprised of a pair of blades having an eccentric cam configuration rotatably mounted in the same plane on a movable elongated arm pivotally secured to said body frame; means for activating said crimping means; means for activating said spanker means; means for heating the plastic-coated container surface to an adhesive condition, said means being positioned opposite at least another of said sealing means; anvil means, the operative face thereof lying in one plane, movably secured to said body frame positioned opposite still another of said sealing means for compressing the folded end against said sealing means; means for activating said anvil means; and means for rotating said mandrel drum.

3. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are elongated and substantially continuous so as to be coextensively positioned relative to the inner seams of the folds of a container end.

6. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said sealing ribs are a plurality of spaced elongated rectangular and cylindrical ribs positioned so as to extend across the inner seams of the folds of a container end.

7. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 2 wherein said sealing means is provided with means for aligning a container inserted thereon, said aligning means comprising a notch situated on the periphery of the sealing head and extending through the thickness thereof.

8. An apparatus for automatically forming and sealing pliable containers having a plastic-coated surface as described in claim 1 wherein said means for sequentially activating said forming means and said spanker means are pistons and wherein the means for activating said crimper means is a movable friction contact head which engages the rearward ends of the crimper means.

9. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface from the interior thereof, sealing means, comprising: a sealing head, said head being provided with a sealing face; a pressure land situated on said sealing face comprised of a plurality of planes, each having dIfferent elevations; and a plurality of sealing ribs superimposed on said pressure land and slightly projecting therefrom.

10. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as described in claim 9 wherein said sealing ribs are situated in a predetermined manner and are of uniform height.

11. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as described in claim 9 wherein said sealing ribs are elongated and substantially continuous so as to be coextensively positioned relative to the inner seams of the folds of a container end.

12. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as describe in claim 11 wherein said sealing ribs are intermittent and in spaced relationship.

14. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as described in claim 9 wherein said sealing ribs are a plurality of spaced elongated rectangular and cylindrical ribs positioned so as to extend across the inner seams of the folds of a container end.

15. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, sealing means as described in claim 10 wherein said sealing head is provided with means for aligning a container inserted thereon, said aligning means comprising a notch situated on the periphery of the sealing head and extending through the thickness thereof.

16. In an apparatus for automatically forming and sealing pliable containers having a plastic-coated surface, forming means, comprising: spanker means operable in preset planes, said spanker means comprised of a pair of juxtapositioned impact blades attached to an arm pivotally secured to the body frame so as to be simultaneously movable on both sides of the crimper means, said blades having outwardly divergently flaring ends which compress the container at the break line against the corner of the sealing head thereby facilitating the folding of the container end at that juncture; and crimper means operable in a plane different from said spanker means, said crimper means comprised of a pair of blades having an eccentric cam configuration rotatably mounted in the same plane on a movable elongated arm pivotally secured to said body frame.

17. A method of automatically forming and sealing pliable containers having a plastic-coated surface, comprising the steps of: positioning a container to be formed and sealed over a pilot flange and a stationary sealing head which are in spatial and parallel alignment with each other so that the multilevelled pressure land and intermittently continuous sealing ribs carried by the face of said sealing head are in a predetermined position relative to said container, and the end thereof which is to be formed and sealed is uppermost; convergingly rotating a pair of crimper blades in the same plane thereby inwardly folding the opposite sides of the container end together so as to cause the other sides thereof to buckle inwardly; while said crimper blades remain in their convergent position in engagement with said container end, pressing a pair of spanker blades against the bend of the buckled portion of the container end thereby swaging the container material located at said bend and folding said buckled portion; heating said folded container end from an external heat source until the plastic coating thereof has acquired an adhesive condition; pressing a movable abutment anvil the face of which lies in one plane againSt the heated folded container end thereby compressing said end between the anvil face and the face of the stationary sealing head so that the internal folds of the folded container end are accommodated by the various elevations of the multilevelled pressure land and the intermittently continuous sealing ribs impress a predetermined sealing pattern upon said internal folds of the folded container end; maintaining said anvil pressure until fusion of the folds of the folded container end occurs; and removing said container from said pilot flange and said sealing head.

18. A method of automatically forming and sealing pliable containers having a plastic-coated surface, comprising the steps of: positioning a container to be formed and sealed over a pilot flange and a stationary sealing head so that one end thereof is uppermost; inwardly folding the opposite sides of said container end by a converging force until the remainder of the sides of said container end buckle inwardly; prior to the release of said converging force, applying a pressure to the bend of the buckled portion of the container end in parallel planes on both sides of the plane in which the converging force is applied and extending normally to the plane of the converging force; heating said folded container end until the plastic coating thereof is in an adhesive condition; compressing said heated end against the stationary sealing head so that a predetermined sealing pattern is impressed upon the internal folds of the folded container end; and removing said container from said pilot flange and stationary sealing head.

19. A method of automatically forming and sealing pliable containers having a plastic-coated surface, as described in claim 17 wherein the positioning of the container on the pilot flange and stationary sealing head is accomplished by aligning the side seam of the container with a notch located on the periphery of the sealing head.

20. A method of automatically forming and sealing pliable containers having a plastic-coated surface, as described in claim 18 which includes the step of passing the heated folded container end through a guide folder prior to sealing the end so that the heated container end is further folded thereby facilitating the subsequent sealing operation.

21. A method for automatically forming pliable containers having a plastic-coated surface, comprising the steps of: inwardly folding the opposite sides of said container end by a converging force until the remainder of the sides of said container end buckle inwardly; and prior to the release of said converging force, applying a pressure to the bend of the buckled portion of the container end in parallel planes on both sides of the plane in which the converging force is applied and extending normally to the plane of the converging force.

22. A method for automatically sealing pliable containers having a plastic-coated surface and mounted on a pilot flange and stationary sealing head having a face comprised of multilevelled pressure land and intermittently continuous sealing ribs carried by said sealing head face, comprising the steps of: heating the folded end of said container end until the plastic coating thereof is in an adhesive condition; compressing said heated end between a movable abutment anvil the face of which lies in one plane and the face of said sealing head so that the internal folds of the folded container end are accommodated by the various elevations of the multilevelled pressure land and the intermittently continuous sealing ribs impress a predetermined continuous sealing pattern upon said internal folds of the folded container end; and maintaining said anvil pressure until fusion of the folds of the folded container end occurs.