EP1339619A1

EP1339619A1 - Pressure indicator

Info

Publication number: EP1339619A1
Application number: EP01990412A
Authority: EP
Inventors: Montserrat Vilalta; Jose Millan; Juan Carlos Coronado; Mariano Penaranda; Antonio Rebordosa
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 2000-12-08
Filing date: 2001-11-14
Publication date: 2003-09-03
Anticipated expiration: 2021-11-14
Also published as: ATE319631T1; CN1479686A; ES2256320T3; AU2002229550A1; HK1059422A1; WO2002046061A1; CN100420612C; DE10060995A1; EP1339619B1; DE50109182D1

Abstract

The invention relates to a pressure indicator (6) for a storage container (15) for food. Said container can be closed in an airtight manner and comprises a connecting device (9) for a vacuum pump used to evacuate the air from inside (22) the storage container (15). The invention is characterised in that the pressure indicator (6) is embodied in the form of a dome-shaped membrane which can fold up into itself. One such pressure indicator (6) facilitates the air evacuation process as the user can see immediately when or if there is still a sufficient vacuum inside (22) the storage container (15). The inventive pressure indicator (6) provides an optically and haptically detectable signal corresponding to the pressure state inside the storage container (15).

Description

pressure indicator

The invention relates to a pressure indicator for a food storage container according to the preamble of patent claim 1.

Systems are already known for the storage of foodstuffs in the household sector which permit preservation under better conditions than if the foodstuffs are stored untreated or without improved storage conditions. One way to improve food storage is to store food in containers under vacuum. Such systems have been shown to produce very good results in avoiding some microorganisms, vermin, mold and yeast growth. It also avoids the oxidation of food, thereby avoiding changes in the moisture and aroma of the food. A problem with such systems is to ensure a sufficient vacuum in the storage containers, especially over a long period of time.

A certain type of visual inspection is possible with a container lid according to WO 88/00560. It describes an opening mechanism for a plastic beverage can. The beverage can has a plastic lid which, if there is a corresponding excess pressure in the interior of the container, has a bulge outwards. It is not possible to make a quantitative statement about how great the overpressure inside the container is.

CH 304 374 discloses a closure lid for a sterilization vessel made of aluminum, which has an essentially circular shape and is placed on a cylindrical aluminum container. A rubber seal is placed between the edge of the lid and the top of the container. In the middle of the container lid there is an additional opening, which is covered by a rubber cap. The rubber cap is used for visual inspection to indicate whether there is a vacuum inside the container. As long as there is a corresponding negative pressure inside the container, the rubber cover cap bulges inwards accordingly. As the vacuum diminishes, this curvature subsides continuously. It is therefore difficult for the observer to decide whether the negative pressure inside the container is still sufficient to ensure the freshness of the food inside the container. The present invention has for its object to provide an improved pressure indicator for a storage container for food available, which avoids the disadvantages of the prior art described.

This object is achieved by a pressure indicator for a food storage container with the features of claim 1. Advantageous embodiments of the invention are described in the subclaims.

The pressure indicator according to the invention has the advantage that it is simple and inexpensive to manufacture and avoids the disadvantages of the prior art. Such a pressure indicator simplifies the evacuation process, since the operator can immediately see when a sufficient negative pressure has been reached in the storage container. The pressure indicator according to the invention provides an optically and haptically detectable signal for the corresponding pressure condition in the interior of the storage container. The optical effect of the membrane, which is made, for example, of an elastomeric plastic material, can be further increased by appropriate color design in a signal color. Depending on how far the pressure indicator protrudes over the outer contour of the valve device or disappears into it under appropriate pressure conditions, a corresponding haptic effect can be achieved which also allows visually impaired users to record the pressure condition inside the storage container.

An advantageous embodiment of the present invention provides the features of claim 2. At ambient pressure in the storage container, the membrane of the pressure indicator protrudes outwards.

A further advantageous embodiment of the present invention provides the features of claim 3. In this way, a clear signal position of the pressure indicator is achieved. When a predefined negative pressure in the interior of the container is reached, the membrane "snaps" inwards. If the spring is selected accordingly, it is ensured that the membrane snaps back into its starting position when a minimum negative pressure in the storage container is exceeded, ie there are only two clear pressure indicator positions: sufficient negative pressure in the Storage container (pressure indicator is snapped) / insufficient vacuum or ambient pressure (pressure indicator is located) in its initial position). The spring element can be formed, for example, by appropriately selecting a resilient plastic material for the membrane of the pressure indicator or by inserting a spring metal into the membrane of the pressure indicator.

A further advantageous embodiment of the invention provides the features of claim 4. This makes it possible to store the storage container and its contents in a freezer and then thaw them in a microwave oven.

A further advantageous embodiment of the invention provides the features of claim 5. The integration of the pressure indicator in the valve device creates a component with multiple functions.

Another advantageous embodiment of the present invention provides the features of claim 6. In this case, a material is preferably selected which has both sufficient rigidity and the required sealing properties. This component can be inexpensively manufactured as an injection molded component and simply mounted on the storage container.

Finally, a further advantageous embodiment of the present invention provides the features of claim 7. The flexible arrangement and universal applicability of the pressure indicator together with storage containers for food are advantageous.

The features of patent claim 8 result in a particularly clearly visible pressure indicator which clearly shows the pressure state.

The snap action of the pressure indicator is achieved by the features of patent claim 9. This means that only the good or bad state of the vacuum is clearly displayed. This avoids a gradual shift in the pressure indicator.

Due to the features of claim 10, the pressure indicator can be folded up particularly smoothly since the side wall does not rub appreciably against one another when rolled up. Due to the features of claim 11, the pressure state can be determined particularly easily because, as soon as the vacuum is too low, the pressure indicator penetrates the display opening, whereas, if the vacuum is sufficient, the pressure indicator does not penetrate the display opening.

Further refinements and advantages of the invention are explained by the description of the exemplary embodiments with reference to the accompanying drawings. In it show:

1 shows a schematic sectional illustration of a first embodiment of a valve device with a pressure indicator according to the invention for a container lid of a storage container for foodstuffs when there is insufficient vacuum in the storage container,

2 shows a schematic sectional view of the valve device with the pressure indicator according to FIG. 1, with a sufficient vacuum in the storage container,

3 shows the valve device according to FIG. 1, but after the vent opening has been released through the opening tab, so that atmospheric pressure is again in the storage container,

4 is a partially sectioned perspective view of a second embodiment of a pressure indicator according to the invention for a storage container for foodstuffs when the vacuum in the storage container is insufficient;

Fig. 5 as Fig. 4, but with the opening flap pivoted upwards to release the vent opening, so that pressure compensation can be produced in the storage container and

6 is a perspective view of a food storage container with a pressure indicator according to FIG. 4. For the sake of simplicity, the same or similar components are identified below with the same reference symbols. In order to avoid repetitions, the same position numbers and the same functions and modes of action must be assigned.

Figures 1 to 3 show a schematic sectional view of a first embodiment of a pressure indicator 6 according to the invention for a storage container 15 (Fig. 4) for food. According to FIGS. 1 to 6, the pressure indicator 6 is connected to a valve device 1 which is attached to a container lid 2. An opening tab 7 is integrally connected to the container lid 2 via a film hinge 32. The opening tab 7 and the container lid 2 are made as an injection molded component from temperature-resistant thermoplastic. The opening tab 7, which is essentially an oval plate in plan view, has a connection device 9 for a suction connection of a vacuum pump, which is essentially formed by a smooth annular surface 18 on the outside 24 of the opening tab 7 and one or more suction openings 17 within the annular surface 18. Such a device is described in the patent application filed by the applicant on the same day, which is entitled "Device for evacuating food storage containers" and which bears the internal company number 06499-PT1 O / Ha. This item is referred to in full here and items from this application may also be the subject of the present application.

On the underside of the opening tab 7, a sealing tongue 3 made of elastomeric plastic is arranged below the connecting device 9 in FIGS. 1 to 6. In the first exemplary embodiment in FIGS. 1 to 3, the sealing tongue 3 is fastened to the opening tab 7 via an annular web 19 and is designed as a disc-shaped component. The web 19 has an air passage 30.

In FIGS. 1 to 6, the opening tab 7 is inserted into an essentially rectangular recess 20 in the container lid 2 of the storage container 15 which is adapted to the opening tab 7. Under the connecting device 9 of the opening tab 7 and the sealing tongue 3, a vent opening 4 is provided in the container lid 2. In the open state, the ventilation opening 4 establishes the connection between the atmosphere and the interior 22 of the storage container 15. In the closed state, the ventilation opening 4 is closed airtight by the sealing tongue 3. The vent 4 forms with the sealing tongue 3 a check valve 40 closing in the direction of the storage container 15.

In addition to the ventilation opening 4, a measuring opening 5 is arranged in the container lid 2 according to FIGS. 1 to 6. The measuring opening 5 is airtightly covered from above by a plastic membrane 29 of the pressure indicator 6 from above. The pressure indicator 6 extends essentially perpendicularly to the plane of the container lid 2 and, according to FIGS. 1, 3, 4 and 5, has an essentially cup-shaped, slightly curved side wall 23 in the improperly vacuum-sealed state, which tapers upwards and ends with a horizontally extending circular bottom 24. The diameter D of the base 24 is smaller than the diameter d of the opening 25 at the foot section 25 of the pressure indicator 6, as is shown in particular in FIG. 4. The design of the pressure indicator 6 as described ensures that the side wall 23 of the pressure indicator is at a vacuum when applied 6 similar to how a rolling membrane pulls into its cavity 26, as shown in FIG. 2.

According to FIGS. 1 to 6, in the opening tab 7 there is a display opening 8 at the location of the pressure indicator 6, through which the pressure indicator 6 extends vertically beyond the outside 33 of the opening tab 7 if there is insufficient underpressure 15 in the interior 22 of the storage container 15 , The pressure indicator 6 is made of an elastomeric plastic and preferably in a signal color, in the present case in red. On the inside, the pressure indicator 6 according to FIGS. 1 to 3 is stiffened by a spring element 12, which preferably consists of a resilient material, such as spring plate or elastomeric plastic, and lies flat against the inside 34 of the pressure indicator 6.

At the free end on the right in FIGS. 1 to 6, the part of the opening tab 7 near the edge has an actuating surface 10. The end of the opening tab 7, starting from the bending edge 35, is slightly beveled upwards. The container lid 2 has the recess 20 so that, since the opening tab 7 is spaced from the bottom 37 of the recess 20 by ribs 29, 36, the actuating surface 10 of the opening tab 7 is comfortably gripped between the fingers and thumb of a user's hand (not shown) and after can be pulled up. In Figures 1 to 3, a bracket 11 is shown, which presses the elastomeric plastic material of the flat foot portion 25 of the pressure indicator 6 to the container lid 2. The bracket 11 is supported on the walls of the container lid 2, not shown in the drawing. In FIGS. 1 to 3, the pot-shaped pressure indicator 6 is thus connected in one piece to the foot section 25, so that the pressure indicator 6 is sealingly connected to the container lid 2 in the clamped state by the retaining bracket 11.

Figures 4 to 6 show a partially sectioned perspective view of a second embodiment of a valve device 1 with the pressure indicator 6 according to the invention for a storage container 15 for food. In this embodiment, too, the opening tab 7 is connected in one piece to the container lid 2 via the film hinge 32. The sealing tongue 3 arranged under the connecting device 9 of the opening tab 7 is connected to the opening tab 7 via a driver 13. Both the sealing tongue 3 as the driver 13, the foot portion 25 and the pressure indicator 6 are made from a single elastomeric plastic part which is attached as an insert to a bead 21 in the recess 20 of the container lid 2. The plastic material used for the pressure indicator 6 has spring properties, so that the snap effect on the pressure indicator 6 also occurs here if either too little or too little vacuum is present. The difference between the embodiment according to FIGS. 1 to 3 and the embodiment according to FIGS. 4 to 6 essentially consists in the fact that, in FIGS FIGS. 4 to 6 these parts are formed by a single elastomeric component, the sealing tongue 3 of which is partially cut out of the foot section 25 and thus forms a gap 28.

Furthermore, a circumferential seal 14 is provided on the edge of the container lid 2 according to FIGS. 4 and 5, which enables an airtight closure with respect to the storage container 15. However, it is also conceivable not to use a seal 14, as shown in FIGS. 1 to 3, so that the lid 2 itself forms a tight seal with the storage container 15. In the closed state of the valve device 1, the foot part 25 is pressed by the circumferential rib 29 against the bottom 37 of the container lid 2 and thus sealed. In the illustration in FIGS. 1 and 3 to 6, the pressure inside the container 22 of the storage container 15 corresponds to the ambient pressure. The pressure indicator 6 therefore protrudes due to its spring preload through the display opening 8 through the opening tab 7 to the outside.

In the illustration according to FIG. 2, there is sufficient underpressure in the interior 22 of the storage container 15. The pressure indicator 6 is therefore sucked into the cavity 26 in the direction of the interior 22 of the container; it is in the folded or snapped state. In this state, the pressure indicator 6 does not or only insignificantly protrude beyond the outer contour of the opening tab 7. The pressure indicator 6 folds like a rolling membrane. The ratio of the diameter D to d as a function of the wall thickness f and the elastic material of the pressure indicator 6 is chosen such that the pressure indicator 6 folds up suddenly from a certain negative pressure, as shown in FIG. 2. If the vacuum in the interior of the container 22 decreases, a point is also reached here where the pressure indicator 6 suddenly moves outwards. This has the advantage of a clear display.

The operation of the two exemplary embodiments is as follows:

When used in a household, the user can first of all find out about the pressure in the interior 22 of the container based on the position of the pressure indicator 6 with the container lid 2 closed. If the bottom of the pressure indicator 6 protrudes outwards through the display opening 8, this means that the pressure inside the container 22 is not sufficient to ensure the storage of foodstuffs under vacuum conditions (see FIGS. 1, 4 and 6).

Now the storage container 15 is evacuated according to Figures 1, 3 and 6. During the evacuation process, a suction connection with a circumferential sealing lip of a vacuum pump (not shown) is placed on the connection device 9 of the valve device 1. Then the vacuum pump is started. As a result, the vent 4 of the valve device 1 opens automatically, since the suction effect allows the sealing tongue 3 to be lifted off the vent 4 and the air contained in the storage container 15 is sucked out by the vacuum pump. According to FIG. 1, air is passed laterally via the ventilation opening 4 past the sealing seat 38 of the sealing tongue 3, around the sealing tongue 3, through which Air passage 30 and suctioned through the connection device 9 to the vacuum pump. When a sufficient negative pressure is reached in the space 22 of the storage container 15, the pressure indicator 6 snaps inward suddenly (FIG. 2). This informs the user that he can end the evacuation process. After lifting the vacuum pump from the connection device 9, the sealing tongue is pressed onto the edge of the vent opening 3, whereby this is automatically sealed airtight. This process also occurs with each return stroke of the vacuum pump so that a vacuum can be built up in the interior 22. The vacuum in the interior 22 now keeps the foodstuffs there fresh for a long time, since the lack of oxygen prevents oxidation of the foodstuffs.

In order to be able to remove fresh foodstuffs from the storage container 15, one grips under the actuating surface 10 with two fingers and swivels the opening tab 7 counterclockwise in FIG. 5 with little effort. 3, the sealing tongue 3 is lifted up above the webs 19 from the sealing seat 38 by the opening tab 7 and the ventilation opening 4 is opened. In the exemplary embodiment according to FIG. 5, the top of the opening tab 7 first strikes the underside of a brim 27 formed on the driver 13 and pulls the driver 13 with the sealing tongue 3 upwards until the sealing tongue 3 lifts off from the sealing seat 38 and counter to it Swivels clockwise upwards (Fig. 5). According to FIGS. 1 to 5, air can now flow into the container interior 22 via the suction opening 17 of the connection device 9 and the ventilation opening 4.

The container lid 2 can now be removed from the storage container 15 without any significant effort. Since the sealing tongue 3 according to FIGS. 4 and 5 is partially separated from the rest of the flat foot part 25 by the essentially U-shaped gap 28, that is to say it is only connected to the rest of the foot section 25 in the left rear area 39, it falls due to its Gravity as a check valve repeatedly on the vent 4, so that vacuuming is not a problem. But it is also conceivable that the opening tab 7 can be snapped onto the container cover 2 by means of clip connections, so that in the closed state the sealing tongue 3 thereby closes the vent opening 4. In FIG. 3, when the opening tab 7 is pivoted about the film hinge 32, the sealing tongue 3 is lifted upwards because it is attached to the opening tab 7 with play to fulfill the check valve function. FIG. 6 shows a perspective illustration of a storage container 15 for foodstuffs made of thermoplastic material with a valve device 1 according to FIG. 4. The storage container 15 has a cuboid-shaped container body 16 and a container lid 2 with a peripheral rim 27 which is essentially rectangular in plan view. The valve device 1 is arranged in a recess 20 on one of the narrow sides of the container lid 2. The actuating surface 10 of the opening tab 7 closes approximately with the outer surface 33 of the container lid 2. Only the pressure indicator 6 protrudes vertically upward from the display opening 8 of the opening tab 7 when the vacuum is insufficient. In the direction of the inside of the container lid 22, in addition to the pressure indicator 6, the circular connection device 9 with the smooth annular surface 18 and the suction opening 17 can be seen, from which the driver 13 projects with its brim 27. The brim 27 serves to better carry the driver 13 when the opening tab 7 is pivoted upwards. Due to the leverage that is formed by the distances R and r (FIG. 5), a relatively small hand force F (FIG. 4) on the gripping surface 10 is sufficient to lift the sealing tongue 3 from the sealing seat 38 when there is still vacuum inside the container 22 is available. The smaller the distance r and the greater the distance R, the easier it is to open the valve device 1.

Claims

claims:

1. Pressure indicator (6) for a storage container (15) for foodstuffs, wherein the storage container (15) can be closed airtight and which also has a connection device (9) for a vacuum pump for evacuating the space (22) of the storage container (15), characterized in that the pressure indicator (6) is designed as a collapsible dome-shaped membrane.

2. Pressure indicator (6) according to claim 1, characterized in that the pressure indicator (6) has a spring element (12) so that it unfolds into its starting position at a predetermined pressure.

3. Pressure indicator (6) according to claim 1 or 2, characterized in that the pressure indicator (6) indicates only two discrete states, namely sufficient negative pressure in the space (22) of the storage container (15) or insufficient negative pressure in the space (22) of the storage container (15).

4. Pressure indicator (6) according to one of the preceding claims, characterized in that the pressure indicator (6) is made of plastic material which are suitable for a temperature range from -40 ° C to + 100 ° C.

5. Pressure indicator (6) according to one of the preceding claims, characterized in that the pressure indicator (6) is provided as an additional component on a valve device (1) and that the valve device (1) further comprises a check valve (40) with a movable sealing tongue ( 3).

6. Pressure indicator (6) according to claim 5, characterized in that the pressure indicator (6) with the sealing tongue (3) is integrally connected.

7. Pressure indicator (6) according to one of the preceding claims, characterized in that the pressure indicator (6) on the container lid (2) or the container body (16) of the storage container (15) is arranged.

8. Pressure indicator (6) according to claim 1, characterized in that the material of the pressure indicator (6) is made of material which is clearly visible in terms of color.

9. Pressure indicator according to claim 1, characterized in that the pressure indicator (6) is substantially pot-shaped and has a flat bottom (24) to which a conically widening ring wall (23) connects.

10. Pressure indicator according to claim 9, characterized in that the ring wall (23) is slightly curved outwards.

11. Pressure indicator according to claim 1, characterized in that the pressure indicator (6) in its initial position penetrates a display opening (8) formed on the opening tab (7).