Double-walled vessel having pressure equalization opening

Abstract

A double-walled vessel (1) is disclosed, which has a pressure equalization opening (24). Said opening is closed by a stopper (4), which has at least one gas passage channel (41). Said channel is configured such that it allows air to pass, while it prevents the penetration of water into the intermediate space. The stopper is preferably made from a silicone-based plastic and fastened to the vessel by means of an adhesive based on acetoxy silicone. For fastening purposes, it may comprise a disk-like fastening flange (43).

Claims

1. A double-walled vessel comprising: an outer vessel body; an inner vessel body arranged in the outer vessel body in such a way that a gas-filled interspace is formed between the inner and the outer vessel body, a pressure compensation opening being present in a limit wall of at least one of the vessel bodies; and a plug sealing the pressure compensation opening, the plug being made of an elastic and hydrophobic material, the plug having at least one gas passage channel extending completely through the plug, the gas passage channel having dimensions that allow a passage of air while being sufficiently small to prevent water from penetrating into the interspace, due to a negative capillarity caused by the hydrophobic properties of the material of the plug.

2. The double-walled vessel as claimed in claim 1, wherein the plug is made from a silicone-based plastic.

3. The double-walled vessel as claimed in claim 2, wherein the plug is fastened to the vessel body with an acetoxy-silicone-based adhesive.

4. The double-walled vessel as claimed in claim 1, wherein the gas passage channel is of self-sealing configuration.

5. The double-walled vessel as claimed in claim 1, wherein the plug comprises a main portion, which extends into the pressure compensation opening and through which the gas passage channel extends, and a fastening flange, which laterally surrounds the main portion and which, at least in some areas, rests flat on the wall of the vessel body.

6. The double-walled vessel as claimed in claim 5, wherein the main portion has a maximum outer diameter which is smaller than a minimum inner diameter of the pressure compensation opening, so that a lateral gap is present between the main portion and a wall region of the vessel body which delimits the pressure compensation opening.

7. The double-walled vessel as claimed in claim 1, wherein the plug has a circumferential annular groove, into which a wall region of the vessel body, which delimits the pressure compensation opening, projects.

8. The double-walled vessel as claimed in claim 5, wherein the fastening flange is glued to the wall of the vessel body.

9. The double-walled vessel of claim 1, wherein the gas passage channel has been formed by piercing of the plug by means of a needle.

10. A method for producing a double-walled vessel, comprising: providing an outer vessel body and an inner vessel body, a pressure compensation opening being present in a limit wall of at least one of the vessel bodies; arranging the inner vessel body in the outer vessel body and connecting the vessel bodies such that a gas-filled interspace is formed between the vessel bodies, a passage of gas through the pressure compensation opening being enabled during the connection; sealing the pressure compensation opening with a plug made of a hydrophobic material, said plug having at least one gas passage channel extending completely through the plug and being dimensioned to cause a negative capillary effect that prevents water from penetrating into the interspace while allowing a passage of air.

11. The method as claimed in claim 10, wherein the plug is produced from an elastic plastics material, by the plastics material or a precursor thereof being poured in liquid form into a mold and then hardened, and wherein the gas passage channel is formed only after the plastics material has at least partially hardened.

12. The method as claimed in claim 10, wherein the gas passage channel is formed by piercing of the plug by means of a needle.

13. A double-walled vessel comprising: an outer vessel body; an inner vessel body arranged in the outer vessel body in such a way that a gas-filled interspace is formed between the inner and the outer vessel body, a pressure compensation opening being present in a limit wall of at least one of the vessel bodies; and a plug sealing the pressure compensation opening, the plug being made of an elastic and hydrophobic material, the plug defining at least one gas passage channel extending completely through the plug, the gas passage channel having a self-sealing configuration so that the gas passage channel is closed in the absence of a pressure difference between the interspace and an exterior of the double-walled vessel, and is open when a pressure difference is applied between the interspace and the exterior, the gas passage channel being configured to widen under the influence of the pressure difference to only such an extent that negative capillarity prevents water from penetrating into the interspace while allowing a passage of air.

14. The double-walled vessel of claim 13, wherein the gas passage channel has been formed by piercing of the plug by means of a needle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention are described below with reference to the drawings, in which:

(2) FIG. 1 shows a central longitudinal section through a double-walled vessel;

(3) FIG. 2 shows a perspective part-view of the vessel of FIG. 1 in partial section;

(4) FIG. 3 shows an enlarged detailed view of the base region of FIG. 1; and

(5) FIG. 4 shows an enlarged detailed view of the base region of a double-walled vessel according to an alternative embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(6) In FIGS. 1 to 3, a first illustrative embodiment of a double-walled vessel according to the present invention is indicated. The vessel 1 is formed from an outer vessel body 2 of silicate glass and an inner vessel body 3, accommodated therein, of the same material. The two vessel bodies are fused together at their respective upper ends 23, 33. The two vessel bodies hence jointly delimit a gas-filled interspace 5. The vessel bodies thus form, with the outer base 21, the outer side wall 22, the inner base 31 and the inner side wall 32, limit walls for the interspace. In one of these limit walls, here in the outer base 21, a pressure compensation opening 24 is present. In the present example, this has a diameter of about 1.5 to 3.5 mm. Since the vessel bodies consist of glass, the shape and dimensions of this pressure compensation opening can be subject to considerable variations, even within a production series. The pressure compensation opening is in any event, however, sufficiently large to allow a rapid pressure compensation between the interspace and the exterior in the fusion of the vessel bodies.

(7) Following the connection of the vessel bodies, this pressure compensation opening is sealed with a plug 4. This has the shape of a flat, circular disk, which has a central pin-like main portion 42 extending into the pressure compensation opening. In the present example, the outer diameter d of the main portion is about 1.5 mm. It is in this case smaller throughout than the inner diameter D of the pressure compensation opening, even when the production tolerances are taken into account. From this pin-like main portion, a disk-like fastening flange 43 extends laterally outward and rests flat on the outer side of the base 21. This fastening flange 43 is glued to the base 21 by means of an adhesive.

(8) The main portion 42 has a central gas passage channel 41. This channel has been formed by piercing of the main portion with a needle having a diameter of, for example, about 0.6 mm. Other dimensions of the needle are, of course, possible. Once the needle has been withdrawn, the gas passage channel is essentially resealed due to the elastic properties of the plug material. In the event of pressure differences between the interspace and the exterior, the elasticity of the material, however, enables the channel to widen sufficiently to allow gas to pass through.

(9) The plug preferably consists of a silicone-based plastic, in the present example of silicone having a hardness of Shore A 70. The plug has been produced by means of injection molding. Due to its hydrophobic properties and the resultant negative capillary effect, the plug, despite the presence of the gas passage channel, prevents water from penetrating into the interspace 5. This is the case even under the aggressive chemical conditions in a dishwasher and when dishes are washed by hand with or without detergent. If hot water is put into the vessel, then the expanding air in the interspace 5 can escape through the gas passage channel 41 and, upon cooling, can force its way back in correspondingly.

(10) In order to fasten the plug to the base 21, a silicone-based glue is used, in the present example in particular an acetoxy-silicone-based glue, as is available, for example, from the company Henkel Loctite Europe under the name Loctite 5366. This glue, on the one hand, exhibits very good adhesion on the silicone material of the plug and, on the other hand, allows very good connection to the glass material of the outer vessel body.

(11) An alternative embodiment is represented in FIG. 4. In contrast to the first embodiment, the pressure compensation opening is here not arranged centrally in the base 21, but is offset to the center axis of the vessel. The plug 4 has a substantially cylindrical-disk-shaped basic form. On the cylindrical shell surface there is formed a circumferential annular groove 44, into which a region of the base 21, which delimits the pressure compensation opening, projects. The plug 4 is thus held in the region of the pressure compensation opening in the base 21, with the aid of this groove, at least partially by form closure. In addition, the plug 4 is also glued to the base 21 in the region of the annular groove. The gas passage channel 41 is formed in the same way as in the first embodiment, by piercing of the at least partially hardened plug 4 by a needle. In comparison to the first embodiment, the second embodiment demands far smaller tolerances for the shape and dimensions of the pressure compensation opening, since the plug is fastened directly in the region of this opening.

(12) Of course, a large number of modifications are possible, and the invention is in no way limited to the above-discussed illustrative embodiments. For instance, the double-walled vessel can have a different shape than the shape, represented here, of a tall drinking glass, for example as a cup with handle or as a jug with pouring spout. The pressure compensation opening sealed by the plug can also be present in another region of the outer wall of the vessel. Though the vessel is preferably made from glass, it can also be made from another material. Correspondingly, other materials for the plug and for the adhesive are also conceivable. Instead of just a single gas passage channel, a plurality of such channels can also be formed.