US3430842A - Valved bag - Google Patents

Description

Mar 1969 GENNOSUKE YAMAGUCHI 3,430,342

VALVED BAG Filed Sept. 22, 1967 Sheet era GENN OSUKE YAMAGUCHI I. J \"EVIOR.

WMMQ r h 959 GENNOYSUKE YAMAGUCHI 3, 3

VALVED BAG Filed Sept. 22, 1967 Sheet 2 of 2 GEN/VOSUKE YAMAGUCHI IN VENT 0R.

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A it s United States Patent 3,430,842 VALVED BAG Gennosuke Yamaguchi, 160 l-chorne, Okusawa, Tamagawa, Setagaya-ku, Tokyo, Japan Filed Sept. 22, 1967, Ser. No. 669,932 Claims priority, application Japan, Sept. 22, 1966,

41/ 62,499 US. Cl. 22962.5 6 Claims Int. Cl. B6511 31/14, 77/14 ABSTRACT OF THE DESCLOSURE A valved bag having a bag body and a flat valve sleeve therefor both of which are formed of thermoplastic material, with the open-ended sleeve mounted internally of the bag body and heat sealed to the bag body. The valve sleeve is flattened by employing heat welded zones along each side thereof and is folded transversely into a plurality of accordion pleats which function to effect improved sealing of the valve sleeve on filling of the bag body.

This invention relates to valved bags, and more particularly to valved bags having improved valve sleeves associated therewith affording, b virture of the valve sleeve construction, a greatly improved sealing effect after filling of the bag.

Specifically the valved bag of the present invention employs a valve sleeve for-med of an openended small tubular sleeve made of thermoplastic material rendered relatively flat by virtue of heat-welded zones provided on both sides of said sleeve. The thus flattened sleeve is provided with transversely extending fold lines from side to side thereof, as hereinafter explained, which results in a valve sleeve of enhanced sealing properties. Additionally the sleeve is provided with any number of air vent orifices through one or both sides of the flattened sleeve, preferably through the area of the first fold, i.e., the outermost fold. The valve sleeve so constructed, may be internally disposed within the bag body at any desired position with respect to an edge of the bag. For example, the sleeve may be located inwardly of any point on the top edge, any point of the side edge or across one corner of the bag. All four edges of the bag body, as hereinafter explained, except for the valve sleeve, are sealed.

It is therefore the objective of this invention to enhance the sealing effect of a valve sleeve in a valved bag by means of an internally provided sleeve of specific construction and to additionally provide trapped air venting means in the sleeve construction whereby the air may escape freely through orifices in the sleeve out of the bag. It is also an object of this invention to provide a valve sleeve structure wherein the valve sleeve will not be forced outside of the bag during filling thereof, but instead will be completely contained internally of the bag.

Valved bags are old in the art, as illustrated by US. Patent Nos. 3,087,670 and 3,018,943. The valves in the bags of the prior art, including these two patents, are generally formed of a single rectangular blank folded into a tube and cannot be expected to provide a very good seal when the bag is filled. The present invention is designed to overcome the inadequate sealing effect of the prior art constructions.

As hereinafter to be described in detail, the present invention is directed to the construction of a valve sleeve employing the following novel features: heat-welded zones provided on both sides of the sleeve to flatten the sleeve and to prevent excessive expansion and abnormal deformation of the valve sleeve; a folded flattened valve sleeve with the surfaces of several corresponding folds on the front and back of the sleeve enhancing the sealing effect Patented Mar. 4, 1969 'ice of the sleeve; air vent orifices provided through one or both walls of the sleeve, preferably in the first, or outermost fold, to permit air trapped in the bag during filling to escape without permitting the contents to spill out. A valved bag internally equipped with such a valve sleeve is offered by this invention.

Other objects and advantages of the invention will become apparent from a study of the following specification when considered in conjunction with the accompanying drawings, in which:

FIGURE 1 is a plan view of a valved bag constructed in accordance with the present invention with the valve sleeve being shown in dotted lines;

FIGURE 2 is a fragmentary sectional view of FIG. 1 taken along the line IIII and showing particularly the details of the valve sleeve;

FIGURE 3 is an enlarged perspective view of the valve sleeve showing more precisely the details thereof;

FIGURE 4- is a sectional view of FIG. 3 taken alOng the line IV-IV; and

FIGURES 5 to 8 are plan views of other embodiments of this invention and showing other locations for the valve sleeve: FIG. 5 illustrating the sleeve being positioned inside the midpoint of the top edge of the bag; FIG. 6 showing the sleeve positioned near the top of the bag at the side thereof; FIG. 7 showing the sleeve positioned inside the midpoint of the side edge of the bag; and FIG. 8 showing the sleeve positioned internally of the bag across a top corner thereof.

To explain a preferred embodiment of this invention and referring to the drawings, the bag 1 is formed of a synthetic resin skin or film, preferably a thermoplastic material, such as, polyethylene, polypropylene, polyester, polycarbonate, or polyvinylchloride, or of a synthetic rubber, or it may be formed as a lamination of said synthetic resin skin and a craft paper or textile.

In this embodiment, the bag 1 is formed preferably of a tube of said synthetic resin skin, molded by inflation, or otherwise formed, being cut to a desired specified length and sealed at the bottom edge 2 and top edge 4 of the formed tubular body, as shown, by heat-welded zones 3 and 29, respectively.

Said bag body may be formed also by employing sheets of synthetic resin folded or laid upon each other and applying heat-welded seals at both side edges and at the top and bottom, as will be readily understood.

The valve sleeve 5 to be enclosed within the bag 1 is preferably formed of an open-ended small tubular sleeve likewise made of a synthetic resin skin molded by the inflation film method, or otherwise produced, of some thermoplastic material, synthetic rubber, or the like material. The tubular sleeve is flattened by employing heatwelded zones 8 and 9 extending along the side edges 6 and 7 of the sleeve, the inner face 11 of the front wall 10 of the sleeve being thus sealed to the inner face 13 of the back wall 12 of the sleeve, along the sides, as clearly shown in FIG. 3.

The thus flattened, open-ended tubular sleeve 5 is then folded, with the fold lines 14, 15 and 16 extending transversely of the sleeve and towards the side edges thereof, to form any desired number of folds. The fold lines need only be unparallel to, or run at an angle to the side edges 6 and 7 of the flattened sleeve, but preferably, as shown, these fold lines extend completely across the sleeve and at right angles to the sides 6 and 7. These fold lines can be easily formed by heating and sudden cooling and/ or quenching.

It will be noted that the heat-welded zones 8 and 9 run throughout the length of the sides 6 and 7 of the sleeve, or slightly spaced inwardly from said side edges and they extend at an angle to the fold lines 14, 15, and 16, preferably at right angles thereto, as shown. In this 3 embodiment, the number of folds or pleats employed is four, 17 being the first fold, 18 the second, 19 the third and 20 the fourth fold. Preferably, the folds are alternated, as shown, to create accordion pleats or fan folds.

Any desired number of orifices 21, 22, 23, 24, 25, 26, 27 and 28 are provided through the front and back walls and 11 of the sleeve 5, as shown, which orifices may be evenly or unevenly spaced between the heat-welded zones 8 and 9 and preferably in the first fold 17 of the valve sleeve. These orifices are intended to function as air vents, their shape, number and size being selected depending upon the nature of the contents to be charged into the bag 1, the particle size, the moisture absorption rate of the material, and other factors. It will be understood that while orifices have been shown through both front and back walls of the sleeve, it may suffice in some instances to merely provide orifices through only one wall of the sleeve.

The material out of which the valve sleeve 5 is formed should not be of too thin a gauge, but preferably thick enough to allow proper expansion and contraction at the folds, similar to an accordion, with adequate restoring or retraction ability. If the material is of too thin a gauge, the fold lines may be lost so that the valve sleeve will not retract after filling but remain a mere fiat sleeve which will not function to seal against loss of contents, etc., as intended.

After the valve sleeve 5 has been formed as recited above, the valve sleeve is ready for insertion into position in the bag body 1 within the top edge 4 prior to heat sealing that top edge 4 prior to heat sealing that top edge. In the embodiment shown in FIG. 1, the valve sleeve 5 is enclosed near the side of the top edge 4 of the bag body. In this instance the valve sleeve is inserted into the bag with the first fold 17, containing the orifices 21 to 28, positioned uppermost and with the fourth fold extending downwardly into the interior of the bag body 1. The inner faces of the top edge 4 of the bag body and the external faces of the top end of the first fold 17 of the sleeve 5 are brought into registry, and holding these surfaces in this position, the bag body is then heat-Welded along the extreme edge of the top 4, thus forming the heat-Welded zone 29, which seals up the entire top edge 4 of the bag body except for the abutting inner faces 11 and 13 of the sleeve 5. Referring to FIG. 2 it will be seen that the heat-welded zone 29 joins and seals the external face of the wall 10 of the sleeve and the external face 31 of the wall 12 of the sleeve to the adjacent inner faces of the bag body 1, i.e., the internal face 33 of the wall 32 and the internal face of the wall 34 of the bag body 1.

The abutting inner faces 11 and 13 of the valve sleeve are preferably given a coating of a suitable material, such as a paint, or the like, to prevent the heat-welding of these surfaces to each other. So coated, the application of pressure and heat exteriorly of the bag body 1 in forming the seal 29, will not seal the inside face 11 of wall 10 of the sleeve 5 to the adjacent inside face 13 of the wall 12 of the sleeve. As a suitable coating or paint, a nitrocellulose dyestuff diluted with alcohol, or the like, may be employed.

Thus, the bag body 1, except for the valve sleeve 5, is completely sealed, with the heat-welded zones 29 and 3 at the top edge 4 and bottom edge 2, respectively. The bag body is thus formed with the valve sleeve 5 securely positioned at a specified location within the bag and with the top edge of the sleeve having a free entry opening 36 for the reception of the filling spout, or the like, for charging of the bag body with the desired contents.

With the valved bag formed as described above, the substance with which the bag is to be filled is preferably forced under pressure into the bag body through the opening 36 of the valve sleeve, the force of the flowing charge separating the valve sleeve from the inner surfaces of the bag body, and if this charging force is adequate,

the folded valve sleeve will extend, or in effect unfold, and assume a tubular form offering a smooth flow path for the material to the interior of the bag body. As will be expected, air will inevitably enter the bag body along With the material during this charging process. Such air as may enter will be disposed of as hereinafter explained. After the blast charging is over, the valve sleeve 5 folds up or contracts under internal pressures and is pressed in the direction of the heat-welded zone 29 at the top edge 4 of the bag body, with the sleeve returning to a flattened condition with the inner surfaces 11 and 13 of the walls 10 and 12 of the sleeve being brought together and with the fold lines 14, 15 and 16 again restored to their original effective condition, and as a result, effectively sealing the sleeve and precluding the entry of any air through the valve sleeve to the interior of the bag body. Additionally, the internal pressure will prevent the folded flattened sleeve from bulging out of the bag body.

Accordingly, by virtue of the construction there will be no abnormality of the folding of the valve sleeve nor failure or bursting of the sleeve during the filling and subsequent sealing process. Particularly, the superposition of the heat-welded zone 29 at the top edge 4 of the bag body over the heat-welded zones 8 and 9 at the sides of the flat valve sleeve will materially strengthen the boundary area of this bag-valve joint, which point is usually deemed the weakest spot in this general type of valved bag. This will thus be effective to prevent separation of the sleeve from the bag body and damage to the valve itself.

The orifices 21 to 28 through the walls 10 and 12 in the first fold 17 of the valve sleeve are disposed inwardly of the seal 29 and hence after filling of the bag will provide vent means for the air trapped in the bag body during the charging of the same, particularly while this bag is being handled, transported or stacked. Air trapped in the bag body at the time of filling will be discharged out of the bag through the opening 36 of the sleeve while the bag is being handled, this being accomplished by the air Within the bag passing the clearances between the inside faces 33 and 35 of the bag body and the outside faces 30 and 31 of the walls 10 and 12 of the first fold of the sleeve, passing through the perforations in the walls of the sleeve 5 to the interior thereof in the first fold 17, forcing past the inner walls of the sleeve in fold 17 and out of the entry mouth 36.

It will be appreciated that the compressed air used for charging a substance through the opening 36 of the valve sleeve 5 into the bag flows out through the orifices 21 to 28 of the sleeve after the blast charging is finished.

FIGURES 5 to 8 illustrate other embodiments of this invention directed mainly to the positioning of the valve sleeve 5 in the bag body. In FIG. 5 the valve sleeve is positioned at a midpoint along the top edge of the bag. FIG. 6 shows one of the valve sleeves positioned in the bag at the top of a side edge thereof, while FIG. 7. shows the sleeve positioned at a midpoint of a side edge. In FIG. 8 is disclosed a valve sleeve provided across one corner of the bag body.

The functions, manner of attachment and the effects achieved of the embodiments illustrated in FIGS. 5 to 8 are the same as the embodiment heretofore described and illustrated in FIGS. 1 to 4.

In the valved bag of this invention, the residual air can be effectively reduced to a minimum. Thus, any damage to the bag and contents while being handled on account of excessively trapped air can be materially and virtually averted and excessive bulging of the bag can be prevented.

Since the valved bag of this invention needs no sealing operation after being charged or filled, there is little likelihood of the bag failing to be sealed properly due to static electricity.

As the valve effects perfect sealing by virtue of internal pressures, the charging operation is carried out more efi'iciently. Moreover, this bag is adaptable for mass production, can readily colored or printed upon, and is highly weatherproof. Thus, this invention achieves a remarkable overall effect and advance in the art.

While the present invention has been explained and described with reference to specific embodiments of structure, it will be understood, nevertheless, that numerous modifications and variations are susceptible of being incorporated without departure from the essential spirit or scope thereof. Accordingly, it is not intended for an understanding of this invention to be limited by the foregoing description nor by the illustration in the annexed drawings, except as indicated in the hereinafter appended claims.

What is claimed is:

1. A valved bag comprising in combination a bag body of thermoplastic material, a flat open-ended valve sleeve of thermoplastic material having a front wall and a back Wall carried by the bag and extending internally thereof from a sealed edge of said bag, the external surfaces of the outer end of said flat valve sleeve being sealed to the inner surfaces of said edge of said bag, said valve sleeve having one or more permanent transverse folds extending from side to side of said sleeve and spaced from the outer end thereof, said front Wall and said back Wall of said valve sleeve being folded in the same folding direction to form said one or more permanent transverse folds, and said bag body being completely sealed except for the inner surfaces of the upper end of said sleeve through which entry may be made during the filling operation.

2. A valved bag as specified in claim 1, wherein said valve sleeve is flattened by heat welding applied along the side edges of said sleeve.

3. A valved bag as specified in claim 1, wherein said valve sleeve is folded into a plurality of accordion pleats or folds.

4. A valved bag as specified in claim 1, wherein air vent means are provided in one of the folds of said valve sleeve to permit venting of air trapped in the bag during filling operation.

5. A valved bag as specified in claim 4, wherein said air vent means comprise small perforations through the wall of said valve sleeve.

6. A valved bag as specified in claim 3, wherein the outermost fold is provided with perforations through the wall of the sleeve to permit air to vent from the interior of the bag to the atmosphere.

References Cited UNITED STATES PATENTS 2,682,902 7/1954 Metzger 22962.5 2,804,257 8/1957 Hasler et al. 229--62.5

FOREIGN PATENTS 246,701 9/1963 Australia.

DAVID M. BOCKENEK, Primary Examiner.

US Cl. X.R. 150-9

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