Bung plug having an integrated pressure compensation means

The invention relates to bung plug (10) having an integrated pressure compensation means for arrangement in a container lid of a liquid container, the bung plug (10) having a valve housing (15) below a plug depression (12), the valve housing (15) being provided with air passage openings (39, 40) and having a receiving pin (16) arranged centrically in the valve housing (15) for arranging a valve diaphragm (17) whose diaphragm hub (18) is arranged on the receiving pin (16), a radially outward ring edge (19) of the valve diaphragm (17) being in contact with a ring shoulder (20) of the valve housing (15), the diaphragm hub (18) being arranged between a depression bottom (14) of the plug depression (12) and a lid hub (22) of a surge lid (21) arranged on the receiving pin (16) and provided with air passage openings (39, 40), a surge disk (32) being provided between the surge lid (21) and the valve diaphragm (17), wherein the surge disk (32) and the surge lid (21) are realized as a unit and the surge lid (21) has a mounting disk (26) arranged at an axial distance from the surge disk (32) for mounting in the valve housing (15), said mounting disk (26) having an outer mounting edge for forming an engagement connection with a mounting seat arranged at an inner side (29) of a housing wall (30) of the valve housing (15).

FIELD OF THE INVENTION

The present invention relates to a bung plug having an integrated pressure compensation means for arrangement in a container lid of a liquid container, the bung plug having a valve housing below a plug depression, the valve housing being provided with air passage openings and having a receiving pin arranged centrically in the valve housing for arranging a valve diaphragm whose diaphragm hub is arranged on the receiving pin, a radially outward ring edge of the valve diaphragm being in contact with a ring shoulder of the valve housing, the diaphragm hub being arranged between a bottom of the plug depression and a lid hub of a surge lid arranged on the receiving pin and provided with air passage openings, a surge disk being provided between the surge lid and the valve diaphragm.

BACKGROUND OF THE INVENTION

A bung plug of the kind mentioned above is known from EP 0 922 649 A1, wherein the surge disk and the surge lid are realized as independent elements, which have to be inserted into the valve housing in a defined installation order when being installed in the valve housing. Installation of the surge lid in the valve housing is also possible independently from a previous arrangement of the surge disk in the valve housing because the surge lid is attached in the valve housing independently from the surge disk via a clamping connection between the surge lid and the receiving pin of the valve housing.

It follows from the above that, on the one hand, it is easily possible for the preceding arrangement of the surge disk in the valve housing to be forgotten or omitted when the surge lid is installed, the desired function of the pressure compensation means thus not being available.

Moreover, the exclusively central attachment of the surge lid at the receiving pin of the valve housing leads to the possibility that the surge lid may fall into the container interior if the clamping connection fails.

SUMMARY OF THE INVENTION

Based on the present state of the art, the object of the invention is to provide a bung plug having an integrated pressure compensation means that allows fail-safe installation of the bung plug owing to its design and that exhibits increased operational safety.

To attain this object, the bung plug according to the invention has the features of claim1.

According to the invention, the surge disk and the surge lid are realized as a unit, and the surge lid has a mounting disk arranged at an axial distance from the surge disk for mounting in the valve housing, said mounting disk having an outer mounting edge for forming an engagement connection with a mounting seat arranged at an inner side of a housing wall of the valve housing.

Because of the design of the surge disk and the surge lid as a unit according to the invention, installation of the surge lid is possible only together with the surge disk, omission of the surge disk when installing the surge lid thus being preluded.

Owing to the engagement connection with the housing wall, a secure fixation of the surge lid to the valve housing is provided, the danger of the surge lid becoming detached from the valve housing or from the bung plug and potentially falling into the container interior thus being eliminated. Moreover, the engagement connection allows defined positioning of the surge lid on the valve housing.

Preferably, the mounting disk and the surge disk of the surge lid are formed contiguously in one piece, which not only means that they form a unit—which in particular also includes the formation of a fitted connection between the mounting disk and the surge disk—during installation, but also that the mounting disk and the surge disk can be produced in a single production process.

For realizing the engagement connection, it is advantageous if the mounting edge is realized as a locking ring and the mounting seat is realized as a locking groove.

In a preferred embodiment of the bung plug, the surge lid has spacer ribs for realizing the axial distance between the mounting disk and the surge disk, and the housing wall has air passage openings radially adjacent to the spacer ribs.

If the surge disk has an outer support edge for supporting the surge disk against a support shoulder formed in the valve housing, the support shoulder provides an installation aid in such a manner that the lid disk merely needs to be positioned against the support shoulder with the support edge of the surge disk so as to produce a relative positioning between the surge lid and the housing wall that is suitable for a secure engagement of the mounting edge of the mounting disk into the mounting seat of the housing wall of the valve housing.

It is particularly advantageous if an underside of the mounting disk of the surge lid adjacent to the lower edge of the bung plug is recessed from the lower edge of the bung plug or is arranged in the same horizontal plane as the lower edge of the bung plug, thus preventing the surge lid from protruding beyond the lower edge of the bung plug and consequently allowing a particularly protected arrangement of the surge lid in the bung plug.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a bung plug10provided with an outer thread11for arrangement in a container lid (not illustrated) of a liquid container. In its upper portion, the bung plug10has a plug depression12having tool access portions13distributed across the circumference of an inner wall of the plug depression12and protruding radially into the plug depression12, said tool access portions13allowing a screwing torque to be transmitted to the bung plug10by means of a suitably designed tool engaging the plug depression12so as to screw the bung plug10into the container lid (not illustrated) or to remove it therefrom.

The plug depression12has a depression bottom14that separates a valve housing15formed in the lower portion of the bung plug10from the plug depression12.

The valve housing15has a receiving pin16arranged centrically on the depression bottom14and used to arrange a valve diaphragm17in the valve housing15, said valve diaphragm17preferably being realized as a rubber diaphragm. In its cross-section, the valve diaphragm17forms a hat-shaped profile, which is illustrated inFIG. 1, and has a diaphragm hub18for arranging the valve diaphragm17on the receiving pin16and a radially outward ring edge19that is configured to come into sealing contact with a ring shoulder20formed at the underside of the depression bottom14and forming a valve seat.

The lower end of the valve housing15is formed by a surge lid21that is inserted into the valve housing15and whose lid hub22is arranged on the receiving pin16in such a manner that the diaphragm hub18of the valve diaphragm17is received between an underside of the depression bottom14and a ring edge23of the lid hub22.

As becomes apparent in particular from a combined view ofFIGS. 1 and 2, the surge lid21has a mounting disk26arranged adjacent to a lower edge25of the bung plug for attaching the surge lid21to a housing wall30of the valve housing15by means of an outer mounting edge realized as a locking ring27and engaging into a mounting seat realized as a locking groove31above the lower edge25of the bung plug on an inner side29of the housing wall30.

Forming a unit with the mounting disk26, the surge lid21has a surge disk32, the unit formed between the mounting disk26and the surge disk32being realized by way of a one-piece contiguous design of the mounting disk26and the surge disk32in the case of the exemplary embodiment illustrated at hand. As shown in particular inFIG. 2, the one-piece connection between the mounting disk26and the surge disk32is made possible by spacer ribs33formed between the mounting disk26and the surge disk32, said spacer ribs33defining an axial distance a between the mounting disk26and the surge disk32.

Between the spacer ribs33, rib spaces34are formed that extend radially inward and into a ring gap35formed in the surge lid21and concentrically surrounding the lid hub22, the rib spaces34together with the ring gap35thus forming air passage openings36that allow a radial air flow a, b directed both outward and inward through the surge lid21and thus allowing, together with air passage openings38formed in the housing wall30on the lower edge25of the bung plug adjacent to the rib spaces34, an air exchange between a container interior and a valve chamber37formed in the valve housing15.

In cooperation with the air passage openings38formed in the housing wall30, the air passage openings36formed in the surge lid21, air passage openings39formed in the depression bottom14and a central air passage opening40, the valve diaphragm17allows both aerating a container interior and deaerating a container interior through a pin bottom41formed in the depression bottom14. In the case of the illustrated exemplary embodiment, a mushroom valve24is arranged in the air passage opening40.

The container interior is aerated under negative pressure formed in the container interior, the ring edge19of the valve diaphragm17being lifted from the ring shoulder20as a result of the negative pressure and an air flow a flowing through the air passage opening39in the depression bottom14, the valve chamber37and the air passage openings36in the surge lid21and the air passage openings38in the housing wall30and into the container interior via the aeration path indicated inFIG. 1. The container is deaerated under positive pressure formed in the container interior in relation to the environment, as a result of which the diaphragm hub18shifts on the receiving pin16against the depression bottom14and opens a ring gap between a ring edge23of the lid hub22and the diaphragm hub18, through which a deaerating flow b can flow around the receiving pin16, into a pin interior42and through the passage opening40formed in the pin bottom41and a protection grid28arranged above the depression bottom14and finally to the outside, as illustrated inFIG. 1. As a result, the valve diaphragm17arranged in the valve housing15, in cooperation with the air passage openings36,38,39,40, thus forms a pressure compensation means integrated in the bung plug10for aerating and deaerating the container interior.

In the case in which, contrary to the illustrated embodiment, no air passage opening40provided with a mushroom valve24is formed in the depression bottom14, gas exchange for pressure compensation is possible in one direction only.

As shown in particular inFIGS. 1 and 2, the surge disk32, which is formed monolithically with the mounting disk26in the case at hand so as to form the surge lid21, is provided with an outer support edge43for supporting the surge disk32against a support shoulder44formed in the valve housing15of the bung plug10. The fact that the surge disk32is supported against the support shoulder44allows a dimensionally elastic pre-tensioned installation of the surge lid21in the valve housing15when the locking ring27of the mounting disk26is fitted into the locking groove31.

As illustrated byFIGS. 1 and 3, the surge lid21is inserted into the valve housing15of the bung plug10in such a manner that an underside45of the mounting disk26is arranged in a recessed manner in relation to the lower edge25of the bung plug.