United States Patent 3595467

A container of flexible sheet material capable of being sealed and provided with a one-way valve. The sheet material of the container has a portion formed with an opening passing therethrough. The one-way valve has at this opening of the sheet material a base member formed with a valve opening which registers with the sheet material opening, this base member being fixed in a fluidtight manner to the sheet material of the container. The valve opening is covered by a flexible resilient element of the one-way valve, in the form of a disc having a periphery situated beyond the valve opening and engaging that surface of the base member which is directed away from the interior of the container. Fixed to this latter surface of the base member is a hollow member defining with the base member a chamber in which the disc is located, and this hollow member has an interior projection holding the disc against the base member with the periphery of the disc extending beyond the projection of the hollow member. This hollow member is itself formed with a discharge opening communicating with the interior space of the chamber at a part thereof which is situated beside the projection in communication with the periphery of the disc. Thus, as long as the atmospheric pressure is greater than the interior pressure of the container the disc will be held against the base member closing the valve opening. However, when the interior pressure in the container exceeds atmospheric pressure the disc will yield to permit a fluid such as a gas at an undesirably high pressure to escape out of the interior of the container into the chamber of the hollow member and out through the discharge opening thereof to the outer atmosphere.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
137/843, 137/852, 220/203.16, 222/396, 222/494, 383/107
International Classes:
B65D77/22; B65D81/20; (IPC1-7): B65D31/14
Field of Search:
150/9 137
View Patent Images:
US Patent References:
3432087PACKAGE VALVE1969-03-11Costello
3430842VALVED BAG1969-03-04Yamaguchi
3374805Pressure relief valve1968-03-26Trevarrow, Jr.
3371849Valved bag of plastic material sheeting1968-03-05Rochla
3197119Bags1965-07-27Hartig et al.
3191807Dispenser adapted for ultra-micro range1965-06-29Rodrigues, Jr.
3081919Combination dispensing and excess pressure relief valve1963-03-19Samuel
2822961Aerosol bomb1958-02-11Seaquist
2738091Bottle cap1956-03-13Maddox
2724543Bag seal1955-11-22Baver

Primary Examiner:
Leclair, Joseph R.
Assistant Examiner:
Lipman, Steven E.
What I claim is

1. A container comprising a flexible sheet material capable of being sealed for closing off the interior of the container from the outer atmosphere, and a one-way valve means carried by said flexible sheet material for preventing outside air from flowing into the container, said one-way valve means including a base member carried by said sheet material, having a surface directed away from the interior of said container, and formed with a valve opening, yieldable means engaging said surface of said base member, extending across said valve opening, and normally assuming a position engaging the latter surface for maintaining said one-way valve means closed, said valve means further including a hollow member fixed to said surface of said base member and defining therewith an inner chamber in which said yieldable means is located, said hollow member being formed with a discharge opening through which said chamber communicates with the outer atmosphere, and said yieldable means responding to an excess of pressure in the interior of said container over the outer atmospheric pressure by yielding to place said valve opening in communication with said chamber until said excess pressure in the interior of said container diminishes to a value where said yieldable means again assumes said position closing said valve opening.

2. The combination of claim 1 and wherein said hollow member of said valve means has an inner projection holding said yieldable means against said surface of said base member.

3. The combination of claim 1 and wherein said sheet material is formed with an opening with which said valve opening registers.

4. The combination of claim 3 and wherein said sheet material includes a thermoplastic sheet portion and said base member being made of a plastic and being welded to said sheet portion in a fluidtight manner.

5. The combination of claim 4 and wherein said thermoplastic sheet portion defines part of the interior of said container, and has an inner surface directed toward the interior of said container, said base member being welded to said thermoplastic sheet portion at said surface thereof in the interior of said container.

6. The combination of claim 1 and wherein said yieldable means is in the form of a flexible disc, said hollow member having an inner projection holding said disc against said inner surface of said base member, and said disc having a peripheral portion extending beyond said projection to be deflected by the excess pressure in the interior of said container when said yieldable means responds to place said valve opening in communication with said chamber.

7. The combination of claim 6 and wherein said chamber surrounds said projection and said disc has a periphery extending beyond said valve opening and beyond said projection.

8. The combination of claim 7 and wherein said disc is made of rubber and is elastic.

9. The combination of claim 7 and wherein said valve opening is situated centrally of said base member and said projection and disc are both coaxially aligned with said valve opening.

The present invention relates to packing within flexible sealed containers and simultaneously to improvement in preserving products which are generally perishable at air contact with the possibility of degassing in the long run, such as coffee or grated cheese (or the like).

The object of the present invention is substantially to achieve the possibility of adopting more economical containers, such as to ensure the same degree in product preservation as with rigid containers at present being used in many instances and further to ensure an excellent preservation of the packed products in the long run.

Thus, it is known, for example, that coffee to be preserved under the best conditions should be isolated from the external environment and have a minimized contact with air and oxygen, particularly to avoid oxidation and resulting going rancid of the essential oils, the latter forming, as a matter of fact, the elements providing flavor and taste.

This is achieved by vacuum packing the coffee.

However, coffee encloses within its alveoli a substantial amount of gas built up during roasting.

This gas is CO2 which slowly escapes from the coffee beans within some period of time (from 2 to 15 days) depending on the type of coffee and roasting degree.

Normally these gases are not removed during the vacuum stage which is accomplished during coffee packing, the operation requiring an excessive time (4 or 5 hours) whereby, following the packing and after some time, a pressure is brought about within the container due to gas emission, as previously stated.

Should the sealed container be rigid, such as tin or glass containers, it is sufficient to make such containers sturdy enough so that they will not yield under the double-stress condition, namely firstly a vacuum stress and secondly a pressure stress.

Nonsealed containers cannot be used for the above purposes since, as such, they would enable coffee to contact the external oxygen and hence could not allow coffee to be preserved.

In the case of flexible sealed containers, along with the problem of the double stress such containers are subjected to, there is also the problem of deformability whereby, while during vacuum stage the containers adhere to the product according to a predetermined shape, during gas generation stage said containers swell and deform.

In order to overcome such drawbacks, there is provided according to the present invention a container comprising a plurality of flexible sheet materials, at least one of which is a thermoplastic material, the container being such as to have a particular resistance to both external pressure and inside generating gas pressure, the container being also provided with a one-way safety valve for allowing the outlet of the inside generating gas when the pressure of said gas will exceed a predetermined value.

These and other significant features of the container according to the present invention will be more apparent from the following description related to the accompanying drawing, schematically showing by mere way of nonrestrictive example an embodiment of the container according to the invention, and particularly:

FIG. 1 is a perspective view of the container;

FIG. 2 is a cross section of said container as taken along line 2-2 of FIG. 1; and

FIG. 3 is a sectional view showing a valve as applied to the container.

The flexible sealed container according to the present invention, essentially conceived for resisting a double-stress condition in subsequent steps, namely an outside-to-inside pressure condition and an inside-to-outside pressure condition, can be made by materials which are generally formed of a plurality of film laminates, the inner of which is of thermosealing material.

Particularly, in the illustrated example, the container is made in the form of a bellows, as shown in FIGS. 1 and 2, wherein the seams are completely thermosealed.

The inner surface of the container, as made of thermoplastic sheet, is designated at 1, whereas at 2 there is designated the outer surface of said container which is made of another material, such as paper.

The longitudinal weld line (FIG. 2) is designated at 3. Welding is accomplished on borders initially laterally projecting, whereupon the weld zone, suitably bent as shown in FIG. 2, is attached to the outer underlying surface 2, namely being adhered by a suitable adhesive shown at 4.

Thereby, a greater resistance is achieved to the stress condition due to pressure generated within the container.

Thus, it will be appreciated that stresses are tangentially transmitted and involve a substantial surface section. Therefore, the container can better endure the strain it is subjected to.

According to the present invention, the container is also provided with a one-way valve means for preventing the external air from entering said container.

With the present invention the container which is formed by the flexible sheet material 1, 2, is capable of being sealed, and the flexible sheet material is formed with an opening, shown in FIG. 3, where the one-way valve means is situated. This one-way valve means includes the base member 5 which is fluid tightly fixed with the flexible sheet material and which is formed with the valve opening 6 which registers with the opening in the sheet material. The rubber disc 7 forms a yieldable means which normally assumes the position illustrated in FIG. 3 engaging the surface of base member 5 which is directed away from the interior of the container and closing the opening 6 with a peripheral region of the disc 7 extending beyond the opening 6. The one-way valve means further includes the hollow member 8 which is fixed with the base member 5 and which defines therewith an inner chamber which accommodates the yieldable means 7. This hollow member 8 has the interior projection 9 engaging the yieldable means 7 for holding the latter against the base member 5 extending across the valve opening 6. The hollow space within the hollow member 8 communicates with a discharge opening 10 formed in the member 8 and communicating with the outer atmosphere, so that in response to an excess of interior pressure over exterior pressure, the yieldable means 7 will provide communication between the valve opening 6 and the hollow interior chamber of the hollow member 8, so that excess pressure will result in sufficient communication between the interior of the container and the outer atmosphere to relieve the excess pressure.

The above-described valve is welded on the thermoweldable portion 1 of the container, the borders 11 of which are shown in FIG. 3.

Practically, in order to apply said valve to the container, an opening is drilled in the container so as to slip in the valve, which is then welded to the container.

The system substantially operated as follows:

The container provided with the valve is filled, for example, with coffee and following evacuation is then sealed.

Therefore, rubber disc 7 is biased by an external pressure (that is, a pressure directed from outside to inside of the container) and then presses against base member 5 about opening 6; thus, some vacuum degree is observed within the container and hence at the surface of disc 7 adjacent opening 6 there is a very slight pressure and, however, considerably less than the external pressure which via discharge opening 10 is exerted on the opposite surface of said disc.

Thus, the rubber disc 7 as pressed on base member 5 will prevent air from entering the container, or the passage of air from the outer space S' to the inner space S.

When, owing to gas generation within the container (or within space S) a reversal in pressure differential occurs, that is pressure in space S being greater than pressure in outer space S', it is apparent that a substantial force will press on disc 7 from its surface facing said opening 6.

The pressure so acting against disc 7 is resisted by resilient rubber reaction and projection 9 of hollow member 8 pressing on said disc.

When the force pressing from the inside of the container on said disc exceeds a predetermined limit, the peripheral portion of the disc will automatically lift allowing the outlet of the gas which so reaches the external space S' through the small discharge opening 10; the gas outlet automatically causes a pressure reduction within the bag or bellows, and therefore disc 7 recloses the passage and prevents air from entering from the outside.

Thus, coffee remains within its environment out of air contact and is so preserved under the best conditions.

Said pressure limit causing the gas outlet can be adjusted by varying the following factors:

1. The thickness of rubber disc 7 (whereby the resilient reaction thereof will vary).

2. The initial pressure provided by projection 9 of hollow member 8.

3. The diameter of said projection.

4. The diameter of opening 6.