Vacuum-tight pressure relief valve for packaging containers

Abstract

A pressure relief valve (1) comprises a main body (2), at least one through opening (51), which extends through the main body (2), a diaphragm (6), which is arranged over the at least one through opening (51), and a fluid (8), which is provided on the main body (2), the fluid (8) being arranged between the diaphragm (6) and the main body (2), the main body (2) having a first sealing region (21), a second sealing region (22) radially outside the first region, and a third sealing region (23) radially outside the second region, the regions being respectively formed as continuously closed, the at least one through opening (51) being arranged between the first sealing region (21) and the second sealing region (22), and the diaphragm (6) covering the first sealing region (21), the second sealing region (22) and the third sealing region (23).

Claims

1. A pressure relief valve embodied free of springs and configured to be fastened on a packaging container, the pressure relief valve comprising: a main body (2), at least one through opening (51), which extends through the main body (2), a diaphragm (6), which is arranged over the at least one through opening (51), and a fluid (8), which is provided on the main body (2), the fluid (8) being arranged between the diaphragm (6) and the main body (2), and the fluid (8) having the effect that the diaphragm (6) is held on the main body (2) by adhesion, the main body (2) having a first sealing region (21), a second sealing region (22) and a third sealing region (23), the first sealing region (21), the second sealing region (22) and the third sealing region (23) being respectively formed as continuously closed, the second sealing region (22) being arranged radially inside the third sealing region (23), the first sealing region (21) being arranged radially inside the second sealing region (22), the at least one through opening (51) being arranged between the first sealing region (21) and the second sealing region (22), and the diaphragm (6) covering the first sealing region (21), the second sealing region (22) and the third sealing region (23), wherein, starting from a central axis (25) of the main body (2) and viewed along a direction perpendicular to the central axis (25), the at least one through opening (51) is arranged between a radially outer edge of the first sealing region (21) and a radially inner edge of the second sealing region (22), wherein the third sealing region (23) is formed in the form of a cone envelope ring, and wherein the first sealing region (21) and the second sealing region (22) respectively lie in a common sealing plane (E) perpendicular to the central axis (25) of the main body (2).

2. The pressure relief valve according to claim 1, the first sealing region (21), the second sealing region (22) and the third sealing region (23) being respectively formed in a ring-shaped manner and concentrically in relation to one another.

3. The pressure relief valve according to claim 1, the first sealing region (21) being in the form of a circular ring area.

4. The pressure relief valve according to claim 1, the second sealing region (22) being in the form of a circular line.

5. The pressure relief valve according to claim 1, wherein a distance (A) between the third sealing region (23) and the diaphragm (6) in an inactive state increases radially inward, and wherein the third sealing region (23) intersects the sealing plane (E).

6. The pressure relief valve according to claim 5, the cone envelope ring having a cone envelope base angle (α) of between 1° and 4° with respect to the sealing plane (E).

7. The pressure relief valve according to claim 1, a first peripheral depression (41) being formed between the first sealing region (21) and the second sealing region (22), and a second peripheral depression (42) being formed between the second sealing region (22) and the third sealing region (23).

8. The pressure relief valve according to claim 7, the first depression (41) and the second depression (42) respectively having a depth (T), starting from the sealing plane (E).

9. The pressure relief valve according to claim 8, a radially inner edge (230) of the third sealing region (23) being arranged at a distance (A) from the sealing plane (E), and a ratio of the distance (A) to the depth (T) being between 0.1 and 0.2.

10. The pressure relief valve according to claim 7, a third depression (43) being formed radially inside the first sealing region (21), and the third depression (43) having a rectangular cross section.

11. The pressure relief valve according to claim 1, the main body (2) being an injection-molded part.

12. The pressure relief valve according to claim 1, the main body (2) also having a peripheral border region (3), which defines a receiving space (R) on the main body (2).

13. The pressure relief valve according to claim 12, the border region (3) having an annular projection (31) protruding radially inward from the border region (3).

14. The pressure relief valve according to claim 1, wherein the at least one through opening (51) is completely arranged outside the first sealing region (21), and wherein the second sealing region (22) surrounds the at least one through opening (51).

15. The pressure relief valve according to claim 1, wherein the first sealing region (21), the second sealing region (22) and the third sealing region (23) are circular and are centered on the central axis of the main body (2).

16. A packaging container comprising at least one pressure relief valve (1), the pressure relief valve (1) having: a main body (2), at least one through opening (51), which extends through the main body (2), a diaphragm (6), which is arranged over the at least one through opening (51), and a fluid (8), which is provided on the main body (2), the fluid (8) being arranged between the diaphragm (6) and the main body (2), the main body (2) having a first sealing region (21), a second sealing region (22) and a third sealing region (23), the first sealing region (21), the second sealing region (22) and the third sealing region (23) being respectively formed as continuously closed, the second sealing region (22) being arranged radially inside the third sealing region (23), the first sealing region (21) being arranged radially inside the second sealing region (22), the at least one through opening (51) being arranged between the first sealing region (21) and the second sealing region (22), and the diaphragm (6) covering the first sealing region (21), the second sealing region (22) and the third sealing region (23), wherein, starting from a central axis (25) of the main body (2) and viewed along a direction perpendicular to the central axis (25), the at least one through opening (51) is arranged between a radially outer edge of the first sealing region (21) and a radially inner edge of the second sealing region (22), wherein the third sealing region (23) is formed in the form of a cone envelope ring, and wherein the first sealing region (21) and the second sealing region (22) respectively lie in a common sealing plane (E) perpendicular to the central axis (25) of the main body (2).

17. A pressure relief valve embodied free of springs and configured to be fastened on a packaging container, the pressure relief valve comprising: a main body (2), at least two through openings (51, 52), which extend through the main body (2), a diaphragm (6), which is arranged over the at least two through openings (51, 52), and a fluid (8), which is provided on the main body (2), the fluid (8) being arranged between the diaphragm (6) and the main body (2), and the fluid (8) having the effect that the diaphragm (6) is held on the main body (2) by adhesion, the main body (2) having a first sealing region (21), a second sealing region (22) and a third sealing region (23), the first sealing region (21), the second sealing region (22) and the third sealing region (23) being respectively formed as continuously closed, the second sealing region (22) being arranged radially inside the third sealing region (23), the first sealing region (21) being arranged radially inside the second sealing region (22), the at least two through openings (51, 52) being arranged between the first sealing region (21) and the second sealing region (22), and the diaphragm (6) covering the first sealing region (21), the second sealing region (22) and the third sealing region (23), wherein, starting from a central axis (25) of the main body (2) and viewed along a direction perpendicular to the central axis (25), the at least two through openings (51, 52) each are arranged between a radially outer edge of the first sealing region (21) and a radially inner edge of the second sealing region (22), wherein each of the at least two through openings (51, 52) are completely arranged outside the first sealing region (21), wherein the second sealing region (22) surrounds both of the at least two through openings (51, 52), wherein the third sealing region (23) is formed in the form of a cone envelope ring, and wherein a first depression (41) is formed in the main body (2) between the first sealing region (21) and the second sealing region (22), and wherein the at least two through openings (51, 52) are respectively arranged between the first sealing region (21) and the second sealing region (22) and respectively open out into the first depression (41).

18. The pressure relief valve according to claim 17, wherein the at least two through openings (51, 52) are formed eccentrically and symmetrically in relation to the central axis (25) of the main body (2).

19. A pressure relief valve configured to be fastened on a packaging container, the pressure relief valve comprising: a main body (2), at least one through opening (51), which extends through the main body (2), a diaphragm (6), which is arranged over the at least one through opening (51), and a fluid (8), which is a silicone oil and is provided on the main body (2), the fluid (8) being arranged between the diaphragm (6) and the main body (2), and the fluid (8) having the effect that the diaphragm (6) is held on the main body (2) by adhesion, the main body (2) having a first sealing region (21), a second sealing region (22) and a third sealing region (23), the first sealing region (21), the second sealing region (22) and the third sealing region (23) being respectively formed as continuously closed, the second sealing region (22) being arranged radially inside the third sealing region (23), the first sealing region (21) being arranged radially inside the second sealing region (22), the at least one through opening (51) being arranged between the first sealing region (21) and the second sealing region (22), and the diaphragm (6) covering the first sealing region (21), the second sealing region (22) and the third sealing region (23), wherein, starting from a central axis (25) of the main body (2) and viewed along a direction perpendicular to the central axis (25), the at least one through opening (51) is arranged between a radially outer edge of the first sealing region (21) and a radially inner edge of the second sealing region (22), and wherein the third sealing region (23) is formed in the form of a cone envelope ring, and wherein the first sealing region (21) and the second sealing region (22) respectively lie in a common sealing plane (E) perpendicular to the central axis (25) of the main body (2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described below on the basis of an exemplary embodiment in conjunction with the figures. In the figures, components that are functionally the same are respectively indicated by the same designations and

(2) FIG. 1 shows a simplified schematic view of a pressure relief valve according to a preferred exemplary embodiment of the invention,

(3) FIG. 2 shows a sectional view of the pressure relief valve of FIG. 1 along the line I-I,

(4) FIG. 3 shows a detail of FIG. 2, and

(5) FIG. 4 shows a detail of a further sectional view of the pressure relief valve of FIG. 1 along the line II-II, the pressure relief valve being in a sealed state.

DETAILED DESCRIPTION

(6) FIGS. 1 and 2 show simplified schematic views of a pressure relief valve 1 according to a preferred exemplary embodiment of the invention. FIG. 1 shows in this case a plan view and FIG. 2 shows a sectional view I-I of the pressure relief valve 1.

(7) The pressure relief valve 1 is connected to a wall 10 of a closed packaging container 100, for reasons of clarity the packaging container 100 and a diaphragm 6 of the pressure relief valve 1 not being depicted in FIG. 1 and only a small section of the wall 10 of the packaging container 100 being shown in FIG. 2. The pressure relief valve 1 is in this case fastened to a side 11 of the wall 10 that is facing an interior space I of the packaging container 100.

(8) The packaging container 100 may be used for packaging products with which it is filled, such as a wide variety of foodstuffs. For example, such a packaging container 100 is suitable as aroma protection packaging for coffee. The pressure relief valve 1 according to the invention in this case achieves the effect that penetration of air into the interior space I of the packaging container 100 is prevented, while in the opposite direction gases can escape from the interior space I of the packaging container 100 into a surrounding area U. Such sealing of the packaging container 100 with at the same time the possibility of equalizing a positive pressure is possible particularly advantageously by the pressure relief valve 1. The pressure relief valve 1 is especially suitable for maintaining a vacuum or a strong negative pressure in the interior space I of the packaging container 100 over a long period of time. If, however, a positive pressure in comparison with the surroundings U occurs due to the product with which the package is filled letting out gas in the interior space I, the pressure relief valve 1 allows gases to escape from the interior space I of the packaging container 100 into the surroundings U. For this, two holes 12, 13, which respectively extend through the wall 10, are formed in the wall 10 of the packaging container 100.

(9) The precise configuration of the pressure relief valve 1 is described in more detail below with reference to FIGS. 1 to 3.

(10) The pressure relief valve 1 comprises a main body 2 and a diaphragm 6. The main body 2 is in this case formed in a pot-shaped manner and substantially concentrically in relation to a central axis 25.

(11) The main body 2 has a base region 20, which is adjoined by an annular border region 3. At an end opposite from the base region 20, the border region 3 is connected to the wall 10 of the packaging container 100. The connection between the border region 3 and the wall 10 is an ultrasonic bond. Consequently, a receiving space R of the main body 2 is enclosed by the base region 20, the border region 3 and the wall 10.

(12) The diaphragm 6 is arranged within the receiving space R. The diagram 6 is formed as a circular film disk of a flexible material and has an outside diameter which corresponds to an inside diameter of the border region 3. As can be seen in FIG. 2, the border region 3 also has an annular projection 31, which protrudes radially inward. The annular projection 31 restricts a mobility of the diaphragm 6 along the central axis 25.

(13) In order to allow sealing of the pressure relief valve 1, especially under vacuum loading, the main body 2 also has a first sealing region 21, a second sealing region 22 and a third sealing region 23. As can be seen in FIG. 1, the first sealing region 21, the second sealing region 22 and the third sealing region 23 are respectively formed in a ring-shaped and continuously closed manner and concentrically in relation to one another.

(14) The more precise arrangement, form and dimensions of the sealing regions 21, 22, 23 can be seen better in the sectional view in FIG. 2, and in particular in the detail represented in FIG. 3.

(15) The first sealing region 21 is formed in the form of a circular ring area, which lies in a sealing plane E. The sealing plane E is in this case arranged perpendicularly to the central axis 25. Also, the second sealing region 22 is formed in the form of a circular line and is arranged radially outside the first sealing region 21. The second sealing region 22 likewise lies in the sealing plane E.

(16) Furthermore, the third sealing region 23 is formed in the form of a cone envelope ring. The third sealing region 23 in this case intersects the sealing plane E. A cone envelope base angle α between the cone envelope ring and the sealing plane E is in this case 2.57° (cf. FIG. 2). As can also be seen in FIG. 3, as a result a radially inner edge 230 of the third sealing region 23 is arranged at a distance A below the sealing plane E.

(17) A first peripheral depression 41 is also formed in the main body 2 between the first sealing region 21 and the second sealing region 22. In cross section, the first depression has the form of a symmetrical trapezoid. Furthermore, a second peripheral depression 42 is formed between the second sealing region 22 and the third sealing region 23. The second depression 42 has in cross section the form of a trapezoid. The first depression 41 and the second depression 42 respectively have a depth T, starting from the sealing plane E. A ratio of the distance A to the depth T is in this case 0.15.

(18) Furthermore, a third depression 43 is formed radially inside the first sealing region 21. When viewed in cross section, the third depression 43 has the form of a rectangle or, since it is arranged centrally, is formed as a blind hole.

(19) FIG. 4 shows a detail of a further sectional view II-II of the pressure relief valve of FIG. 1. As can be seen in FIG. 4, formed in the main body 2 are two through openings 51, 52, which respectively extend through the base region 20 of the main body 2 and are arranged substantially parallel to the central axis 25. The two through openings 51, 52 are respectively arranged between the first sealing region 21 and the second sealing region 22 and respectively open out into the first depression 41. Moreover, the two through openings 51, 52 are formed eccentrically and symmetrically in relation to the central axis 25 of the main body 2, as can also be seen in the plan view in FIG. 1. The two through openings 51, 52 are formed in cross section in a trumpet-shaped manner, which has particularly favorable effects on the one hand on the production of the main body 2, and on the other hand on the flow conditions during an outflow of gas. In this case, the through openings 51, 52 taper in the direction of the diaphragm 6.

(20) Furthermore, a fluid 8, which here is a silicone oil, is provided on the base region 20. By means of the fluid 8, the diaphragm 6 is held on the base region 20. As a result of the capillary effect, the fluid 8 is distributed uniformly between the diaphragm 6 and the base region 20. By adhesion in between, the fluid 8 in this case ensures that the diaphragm 6 is held on the base region 20 by means of an adhesive force.

(21) The way in which the pressure relief valve 1 functions is described below.

(22) FIGS. 2 and 3 show in this case an inactive state of the pressure relief valve 1, that is to say when substantially the same pressure prevails between the interior space I and the surroundings U, and consequently no force is exerted on the diaphragm 6. In this inactive state, the diaphragm 6 is undeformed, and consequently completely parallel to the sealing plane E. The fluid 8 has the effect in this case of already preventing in this inactive state air from the surroundings U from being able to penetrate into the interior space I.

(23) FIG. 4 shows a sealed state of the pressure relief valve 1. This sealed state exists whenever there is a pressure gradient between the surroundings U and the interior space I, that is to say whenever a vacuum or at least a negative pressure with respect to the surroundings U prevails in the interior space I. This pressure gradient brings about a force on the diaphragm 6, which presses the diaphragm 6 in the direction of the sealing regions 21, 22, 23. In this case, the diaphragm 6 is made to rest against all three sealing regions 21, 22, 23. In this case, there is surface-area contact between the first sealing region 21 and the diaphragm 6. The second sealing region 22 and the diaphragm are in linear contact. The arrangement of the third sealing region 23 in such a way that the radially inner edge 230 lies at a distance A below the sealing plane E has the effect that the sealing region 23 and the diaphragm 6 are not in contact in the region of the edge 230, but only radially further outside the contact point 231. This contact point 231 lies outside the radially inner third of the area of the third sealing region 23. This makes it possible that the diaphragm 6 is in each case pressed strongly against the first sealing region 21 and against the second sealing region 22, in order to ensure particularly good and reliable sealing of the through openings 51, 52. Since furthermore the diagram 6 is formed from a material with a certain flexibility, the first sealing region 21 and the second sealing region 22 can be pressed slightly into the diaphragm 6, which further encourages a particularly good sealing effect. Consequently, penetration of air into the interior space I of the packaging container 100 is prevented particularly efficiently, since the diaphragm 6 of the pressure relief valve 1 closes off the through openings 51, 52 particularly well as a result of the specific configuration of the sealing regions 21, 22, 23. The pressure relief valve 1 consequently allows the vacuum in the interior space I of the packaging container 100 to be maintained over a particularly long period of time.

(24) However, a vacuum in the interior space I of the packaging container 100 may be ended by packed products giving off gas. Furthermore, if the products give off a great amount of gas, a positive pressure may occur in the interior space I with respect to the surroundings U. If there is such a positive pressure in the interior space I, the gas occurring can flow out through the pressure relief valve 1 to the outside into the surroundings U. For this, in the pressure relief valve 1 there forms a gas channel, which extends from one or both of the through openings 51, 52 through the fluid 8, and thereby slightly raises the diaphragm 6 at its border. Through this gas channel and via the holes 12, 13 in the package, the gas can flow out into the surroundings U, whereby a pressure equalization is brought about.

(25) As soon as the pressure is sufficiently equalized, the gas channel through the fluid 8 is closed again and the diaphragm 6 is drawn back again in the direction of the sealing regions 21, 22, 23 by the adhesive force of the fluid 8, so that the pressure relief valve 1 provides a seal again.