CAPSULE FOR BEVERAGE PREPARATION WITH INTEGRALLY FORMED SEALING MEMBER

Abstract

The invention relates to a capsule (10) designed for preparing a beverage upon injection of liquid into the capsule by means of a beverage preparation machine. The capsule (10) comprises a cup-shaped base body (1) for holding beverage preparation ingredients and a flange-like rim (2) with a sealing member (3) comprising an inner and an outer series (4,5) of arc-shaped protrusions (4a,5a), wherein the base-body (1), the flange-like rim (2) and the sealing member (3) are made integrally from metallic material such as aluminum, in which the inner and outer series (4,5) of the sealing member (3) are concentrically arranged on a surface (2a) of the flange-like rim (2) such as to form an annular space (6) there-between for receiving a sealing surface (21a) of a capsule engagement member (21) of the beverage preparation machine (20). The respective arc-shaped protrusions (4a,5a) of the inner and outer series (4,5) are continuous protrusions with circumferentially extending gaps (4b,5b) formed there-between, wherein the respective arc-shaped protrusions (4a,5a) of the inner and outer series (4,5) are arranged such as to circumferentially overlap outside the circumferentially extending gaps (4b, 5b) of the inner and outer series (4, 5) in side view of the capsule, and wherein the arc-shaped protrusions (4a,5a) of the inner and outer series (4,5) are locally connected together by at least one bridging element (8) positioned proximate to each circumferentially extending gaps (4b, 5b) of the inner and outer series (4, 5).

Claims

1. A capsule designed for preparing a beverage upon injection of liquid into the capsule by a beverage preparation machine, the capsule comprising a cup-shaped base body for holding beverage preparation ingredients and a flange-like rim with a sealing member comprising an inner and an outer series of arc-shaped protrusions, wherein the base-body, the flange-like rim and the sealing member are made integrally from metallic material, wherein the inner and outer series of the sealing member are concentrically arranged on a surface of the flange-like rim such as to form an annular space there-between for receiving a sealing surface of a capsule engagement member of the beverage preparation machine, wherein the respective arc-shaped protrusions of the inner and outer series are continuous protrusions with circumferentially extending gaps formed there-between, wherein the respective arc-shaped protrusions of the inner and outer series are arranged such as to circumferentially overlap outside the circumferentially extending gaps of the inner and outer series in side view of the capsule, and wherein the arc-shaped protrusions of the inner and outer series are locally connected together by at least one bridging element positioned proximate to each circumferentially extending gaps of the inner and outer series.

2. The capsule of claim 1, wherein the inner and outer series of the arc-shaped protrusions each comprise at least two arc-shaped protrusions.

3. The capsule of claim 1, wherein the at least one bridge element extends transversally between the arc-shaped protrusions of the inner and outer series and closes the annular space between the inner and outer series of arc-shaped protrusions.

4. The capsule of claim 1, wherein the at least one bridge element is integral with the arc-shaped protrusions of the inner and outer series.

5. The capsule of claim 1, wherein the overlap between the respective arc-shaped protrusions equals at least 20 to 25% of an arc length (L) of the respective overlapping protrusions.

6. The capsule of claim 1, wherein the overlap angular length between the respective arc-shaped protrusions is between 5° and 85°.

7. The capsule of claim 1, wherein the respective arc-shaped protrusions of the inner and outer series are arranged equidistant to each other about the circumference of the base-body such as to form constant circumferentially extending gaps between the respective protrusions.

8. The capsule of claim 1, wherein the inner and outer series of arc-shaped protrusions are arranged distant from the cup-shaped base body and an outer periphery of the flange-like rim.

9. The capsule of claim 1, wherein the inner and outer series of arc-shaped protrusions are arranged at a radial distance of between 0.6 to 1.2 mm.

10. The capsule of claim 1, wherein the capsule body, the flange-like rim and the sealing member are produced by deep drawing an initially flat metal sheet.

11. The capsule of claim 1, wherein the capsule is made from aluminum.

12. The capsule of claim 1, wherein the capsule further comprises a closing membrane connected to the base body and/or the flange-like rim of the capsule.

13. The capsule according to claim 12, wherein the closing membrane is connected to a surface of the flange-like rim opposite to the surface at which the inner and outer series of arc-shaped protrusions are arranged.

14. The capsule according to claim 12, wherein the closing membrane is an aluminum foil sealed to the flange-like rim and/or the base body.

15. A system comprising a capsule designed for preparing a beverage upon injection of liquid into the capsule by a beverage preparation machine, the capsule comprising a cup-shaped base body for holding beverage preparation ingredients and a flange-like rim with a sealing member comprising an inner and an outer series of arc-shaped protrusions, wherein the base-body, the flange-like rim and the sealing member are made integrally from metallic material, wherein the inner and outer series of the sealing member are concentrically arranged on a surface of the flange-like rim such as to form an annular space there-between for receiving a sealing surface of a capsule engagement member of the beverage preparation machine, wherein the respective arc-shaped protrusions of the inner and outer series are continuous protrusions with circumferentially extending gaps formed there-between, wherein the respective arc-shaped protrusions of the inner and outer series are arranged such as to circumferentially overlap outside the circumferentially extending gaps of the inner and outer series in side view of the capsule, and wherein the arc-shaped protrusions of the inner and outer series are locally connected together by at least one bridging element positioned proximate to each circumferentially extending gaps of the inner and outer series and a beverage preparation machine designed to provide heated and/or pressurized liquid into the capsule for preparing a beverage upon interaction of the liquid with ingredients held within the capsule.

16. A cup-shaped base body of a capsule for holding beverage preparation ingredients and a flange-like rim with a sealing member comprising an inner and an outer series of arc-shaped protrusions, wherein the base-body, the flange-like rim and the sealing member are made integrally from metallic material, wherein the inner and outer series of the sealing member are concentrically arranged on a surface of the flange-like rim such as to form an annular space there-between for receiving a sealing surface of a capsule engagement member of the beverage preparation machine, wherein the respective arc-shaped protrusions of the inner and outer series are continuous protrusions with circumferentially extending gaps formed there-between, wherein the respective arc-shaped protrusions of the inner and outer series are arranged such as to circumferentially overlap outside the circumferentially extending gaps of the inner and outer series in side view of the capsule, and wherein the arc-shaped protrusions of the inner and outer series are locally connected together by at least one bridging element positioned proximate to each circumferentially extending gaps of the inner and outer series.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0057] Further features, advantages and objects of the present invention will become apparent for a skilled person when reading the following detailed description of embodiments of the present invention, when taken in conjunction with the figures of the enclosed drawings.

[0058] These drawings depict only some embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. Hence, it will be appreciated that the invention as claimed is not intended to be limited in any way by these examples.

[0059] FIG. 1a is a perspective side view of a preferred embodiment of a capsule according to the invention presenting a bridging element in between the arc shaped protrusions.

[0060] FIG. 1b is a detail of a bridging element that could be used in a capsule according to FIG. 1a.

[0061] FIG. 1c is a detail of a bridging element that could be used in a capsule according to FIG. 1a.

[0062] FIG. 2 is a top view of the capsule according to FIG. 1a.

[0063] FIG. 3 is a schematic top view onto a preferred embodiment of a capsule according to the invention.

[0064] FIG. 4 is a cross sectional side view of a protrusion of the sealing member according to the invention.

[0065] FIG. 5a is a sectional side view in direction B-B of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

[0066] FIG. 5b is a sectional side view in direction B-B of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

[0067] FIG. 6a is a sectional side view in direction A-A of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

[0068] FIG. 6b is a sectional side view in direction A-A of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

[0069] FIG. 7a is a sectional side view in direction D-D of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

[0070] FIG. 7b is a sectional side view in direction D-D of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

[0071] FIG. 8a is a sectional side view in direction C-C of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine before engaging with each other.

[0072] FIG. 8b is a sectional side view in direction C-C of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine after engaging with each other.

DETAILED DESCRIPTION OF THE FIGURES

[0073] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof.

[0074] In the drawings, similar symbols and references typically identify similar components, unless context dictates otherwise.

[0075] The illustrative embodiments described in the detailed description and drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the claimed subject matter presented here.

[0076] It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

[0077] As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean including, but not limited to.

[0078] Any reference to prior art documents in this specification is not to be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

[0079] FIG. 1a and FIG. 2 presenting a perspective side view and a top view of a capsule will be described jointly as related to a preferred embodiment of the invention.

[0080] Additionally, FIGS. 1b and 1c presenting different bridging element that could be used in a capsule according to the invention will be described in connection with FIG. 1a and FIG. 2.

[0081] FIG. 1a and FIG. 2 relate to a preferred embodiment of a capsule 10 according to the invention. The capsule 10 comprises a cup-shaped base body 1. The base body 1 comprises a closed end 10a, a sidewall 10b forming the external surface of the base body 1 and an open end 10c. The closed end 10a may serve as an injection face during a beverage preparation process, which may be opened by a dedicated injection member of a beverage preparation machine 20 (presented in FIG. 5a and followings).

[0082] The capsule 10 further comprises a flange-like rim 2 which is preferably arranged at the open end 10c of the capsule 10. The flange-like rim 2 may extend radially outwardly from lateral sidewalls 10b of the cup-shaped base body 1. The flange-like rim 2 is preferably arranged transversally to a rotational axis Y of the capsule 10 (rotational axis Y also corresponds to the longitudinal axis A of the capsule 10).

[0083] The flange-like rim 2 presents at least one upper annular surface 2a, said surface being directed towards the capsule base body 1 thus facing away from the open end 10c of the capsule, at least one lower annular surface 2b, which surface 2b is directed away from the capsule base body 1 and a curled outer edge 2c at its outer periphery (extremity of the flange-like rim 2 opposite the base body 1).

[0084] In the shown embodiment, the capsule is preferably made of aluminum.

[0085] At the open end 10b of the capsule base body 1 a closing membrane 9 may be arranged. The closing membrane 9 is preferably connected to the flange-like rim 2 (see for example FIG. 5a). The closing membrane 9 is preferably connected to at least one lower annular surface 2b of the flange-like rim 2, which surface 2b is directed away from the capsule base body 1.

[0086] Alternatively, the closing membrane 9 may be connected to the base body 1 or to both the base body 1 and the flange-like rim 2.

[0087] The closing membrane 9 is preferably an aluminum foil sealed to the flange-like rim 2.

[0088] The cup-shaped base body 1 preferably encloses beverage ingredients suitably for preparing a liquid comestible upon interaction with liquid injected into the capsule 10. The ingredients are preferably enclosed by the cup-shaped base body 1 and the closing membrane 9. The beverage ingredients may be roasted ground coffee or other kinds of ingredients as previously described.

[0089] For the preparation of a beverage, the capsule 10 is inserted into the dedicated beverage preparation machine 20 (part of which is presented in FIGS. 5a to 8b). During the extraction process, an engagement member 21 (presented in FIGS. 5a to 8b) of the beverage preparation machine 20 is engaged with the capsule 10: When the capsule 10 is placed into the beverage preparation machine 20, the engagement member 21 is lowered onto the capsule 10 by means of a dedicated closing force F.

[0090] The engagement member 21 comprises a sealing profile presenting at least one sealing surface 21a (presented in FIGS. 5a to 8b) coming into contact with the capsule 10.

[0091] A radial length L of the sealing surface 21a is defined. The radial length L of the sealing is preferably between 0.5 to 2.0 mm.

[0092] Going in more detail, the flange-like rim 2 comprises an integrally formed sealing member 3 that is arranged at the upper annular surface 2a of the flange-like rim.

[0093] As mentioned, the flange-like rim 2 comprises an integrally formed sealing member 3 which is arranged at an upper annular surface 2a of the flange-like rim. The annular surface 2a is arranged opposite to the surface 2b to which the closing membrane 9 is preferably connected. The annular surface 2a is thus facing away from the open end 10b of the capsule.

[0094] The sealing member 3 comprises an inner and an outer series of arc-shaped protrusions 4,5, which are concentrically arranged on the surface 2a of the flange-like rim 2. The inner and outer series 4,5 of arc-shaped protrusion are integrally formed with the flange-like rim 2. This means that they are formed of same material as the flange-like rim and from the flange-like rim such as (and are not add-on parts) to protrude from the surface 2a.

[0095] The inner and an outer series of arc-shaped protrusions 4,5 are arranged to form an annular space 6 there-between for receiving a sealing surface 21a of a capsule engagement member 21 of the beverage preparation machine 20 (see for example FIG. 5a). Therefore, a radial distance d between the inner and outer series 4,5, is preferably chosen such as the protrusions suitably interact in sealing engagement with the dedicated sealing surface 21a of the engagement member 21. More particularly, in the overlap region (FIG. 5a, 5b for example), the dedicated sealing surface actually splits into a sealing surface portion 21aa which engages the protrusions 4b of the outer series and a sealing surface portion 21ab which engages the protrusions 4a of the inner series. The radial distance d is preferably between 0.6 to 1.2 mm, more preferably between 0.8 and 1.0 mm. The annular space 6 between the inner and outer series 4,5 is preferably void of any protrusion. The annular space 6 thus preferably comprises an essentially flat bottom surface 2d which interconnects adjacent arc-shaped protrusions of the inner and outer series 4,5.

[0096] The sealing member 3 further comprises at least one bridging element 8. The bringing elements 8 are located between the arc-shaped protrusions 4a,5a of the inner and outer series 4,5 and are locally connecting them.

[0097] In more detail, in the overlapping area of the inner and outer series of arc-shaped protrusions 4,5, and in between the inner and outer series 4,5 of arc-shaped protrusions 4a,5a, there is at least one bridging element disposed transversally to the arc-shaped protrusions 4a,5a.

[0098] Hence, the bridging elements 8 are positioned transversally between the arc-shaped protrusions 4a,5a of the inner and outer series 4,5 and are thereby closing the annular space 6 between the inner and outer series of arc-shaped protrusions 4,5.

[0099] FIGS. 1b and 1c are presenting bridging elements 8 that may be used in the capsule 10 of FIG. 1a.

[0100] In FIG. 1b, the bridging element 8 extends transversally and perpendicularly between the arc-shaped protrusions 4a,5a and has a small lateral extension. The lateral extension is about 0.2 to 1 mm.

[0101] In FIG. 1c the bridging element 8 presents a lateral extension that is larger, about 1.5 to 3 mm.

[0102] The transversal extension of the bridging elements 8 corresponds to the radial distance d between the inner and outer series of arc-shaped protrusions 4,5 and thus relates to the radial extension of the annular space 6.

[0103] In the proposed embodiment presented in the figures, the bridging elements 8 are extending radially (transversally and according to the radius of capsule). However, other configuration of the bridging elements may be envisaged. For example, the bridging elements may connect arc shaped protrusions 4a,5a of the inner and outer series in an oblique way. The extension of the bridging elements will then be higher that the radial distance d previously defined.

[0104] As presented, the bridging elements 8 are integral with the arc-shaped protrusions 4a,5a of the inner and outer series 4,5.

[0105] The key function of the bridging elements 8 is to stop possible side flow that could happen in case the engagement member 21 would not enter down to the bottom of the annular space 6 between the inner and outer series 4,5 of arc shaped protrusions 4a, 5a. The height of the bridging elements 8 should be enough to create tightness with the engagement member 21 of the beverage preparation machine, but it should not be too high, thus preventing the engagement member to enter completely in between the inner and outer series 4,5 arc shaped protrusions 4a, 5a. The bridging elements 8 may be deformed by the engagement member 21 when said engagement member 21 is engaging in the annular space 6 between the inner and outer series 4,5 of arc shaped protrusions 4a, 5a.

[0106] For example, the bridging elements 8 may have a height, measured from the surface 2a of the flange-like rim 2, between 0.1 and 0.5 mm.

[0107] The cup-shaped base body 1, the flange-like rim 2 and the sealing member 3 are integrally formed, i.e. by one single piece made from the same material. Accordingly, the cup-shaped base body 1, the flange-like rim 2 and the sealing member 3 can be manufactured from the same material by a forming process. In particular, the base body 1, the flange-like rim 2 and the integrally formed sealing member 3 can be formed in a deep-drawing process. The deep drawing process may require more than one deep drawing step to properly form from a flat piece of material the body of the capsule and the sealing member.

[0108] The base body 1, the flange-like rim 2 and the sealing member 3 are formed of one piece made of metal, preferably of aluminum, most preferably an aluminum alloy.

[0109] The inner and an outer series of arc-shaped protrusions 4,5 and the bridging elements 8 are preferably arranged on the surface 2a distant from an outer circumferential edge or outer end 2c of the flange-like rim 2. The inner and outer series 4,5 are further arranged distant from the cup-shaped base body 1 of the capsule 1. The inner and outer series of arc-shaped protrusions 4,5, is preferably arranged at an annular portion of the surface 2a of the flange-like rim 2 which is nearer to the cup-shaped body 1 than to the outer end 2c. The relative position of the inner and outer series of arc-shaped protrusions on the flange-like rim naturally depends on the matching position of the sealing surfaces determined by the dimensions of the engaging member.

[0110] The bridging elements 8 are arranged transversally between the inner and outer series of arc-shaped protrusions 4, 5.

[0111] The inner and outer series of arc-shaped protrusions 4,5 each comprise individual arc-shaped protrusions 4a,5a arranged at a predefined radius about a rotational axis Y of the capsule 10. The inner and outer series of the arc-shaped protrusions 4,5 each preferably comprise at least two, more preferably at least three, four, five or six arc-shaped protrusions 4a,5a. The respective arc-shaped protrusions 4a,5a of the inner and outer series 4,5 are preferably continuous protrusions with gaps 4b,5b formed there-between. Clearly, the length of each arc-shaped protrusion 4a, 5a along the circumference will depend on their number and the higher the number, the short the length.

[0112] As mentioned, the bridging elements 8 are positioned proximate to the extremities of the respective arc-shaped protrusions 4a,5a in the overlapping portions. The number of bridging elements 8 then depends on the number of arc-shaped protrusions and overlapping portions.

[0113] The respective arc-shaped protrusions 4a,5a of the inner and outer series 4,5 are arranged such as to overlap in side view of the capsule. The respective arc-shaped protrusions 5a of the outer series 5 thus overlap with circumferentially extending gaps 4b formed between the respective arc-shaped protrusions 4a of the inner series 4 in side view of the capsule and vice versa. The overlap between the respective arc-shaped protrusions 4a,5a preferably equals at least 20 to 25%, more preferably 30 to 35% of an arc length L of the respective overlapping protrusions 4a,5a. The respective arc-shaped protrusions 4a,5a of the inner and outer series 4,5 are thus arranged at different angles along the 360° circumference of the flange-like rim 2 when seen in top view.

[0114] The respective arc-shaped protrusions 4a,5a of the inner and outer series 4,5 may be arranged circumferentially at equidistance to each other about the circumference of the base-body such as to form constant circumferentially extending gaps 4b,5b between the respective protrusions 4a,5a in the respective series 4,5.

[0115] Hence, the bridging elements 8 are located near the respective circumferentially extending gaps 4b,5b.

[0116] FIG. 3 relates to a schematic top view onto a capsule 10 according to the invention in which the respective radii of the capsule 10 are indicated. As shown in FIG. 3, the capsule base body 1 and the flange-like rim 2 merge at a circumferential edge indicated as r1 and which radius preferably lies between 12 and 18 mm, and most preferably is 15 mm. The outer radius r6 of the flange-like rim 2 at the outer end 2c preferably lies between 18 and 20 mm, and most preferably is 18.5 mm.

[0117] The difference between r2 and r3 corresponds to a radial extension of the arc-shaped protrusions 4a and the respective intermediate gaps 4b of the inner series of protrusions 4 and preferably lies between 0.3 and 1.3 mm, more preferably between 0.5 and 1.0 mm.

[0118] The difference between r4 and r5 corresponds to a radial extension of the arc-shaped protrusions 5a and the respective intermediate gaps 5b of the outer series of protrusions 5 and preferably lies between 0.3 and 1.3 mm, more preferably between 0.5 and 1.0 mm.

[0119] The difference between r3 and r4 corresponds to a radial extension respectively radial distance d of the arc-shaped protrusions 4a,5a as indicated above. A particularly preferred value for the radial distance d is between 0.7 and 1.1 mm, and most preferably is 0.9 mm.

[0120] The bridging elements 8 are extending radially between r3 and r4 in the annular space 6 created between the inner and the outer series of arc-shaped protrusions 4,5.

[0121] The overlap angular length A between the respective arc-shaped protrusions is between 5° and 85°, preferably between 10° and 70°, most preferably between 20° and 60°.

[0122] FIG. 4 relates to a cross section side view of an exemplary embodiment of an arc-shaped protrusion 4a,5a. The arc-shaped protrusions 4a,5a preferably comprise essentially the same dimensions in sectional side view. However, the arc-shaped protrusions 4a, 5a could also have different dimensions in sectional side view.

[0123] The respective protrusions 4a,5a preferably comprise a lower base portion B with two opposing linear wall sections b1 and b2 and an upper portion A with two opposing rounded wall sections a1 and a2. The two opposing rounded wall sections a1 and a2 of the upper portion A are preferably joined by a rounded tip portion C.

[0124] The two opposing linear wall sections b1,b2 are preferably arranged to approach towards the upper portion A of the respective protrusions 4a,5a. The two opposing linear wall sections b1,b2 are preferably arranged at an angle α of inclination of between 3 to 12°, more preferably of between 5 to 10° with respect to the normal N of the flange-like rim 2 and/or with respect to a rotational axis Y of the capsule 10.

[0125] The two opposing rounded wall sections a1,a2 of the upper portion A preferably comprise a radius R1 of between 0.5 to 5.5, more preferably between 1 and 5 mm. The rounded tip portion C preferably comprise a radius R2 of between 0.2 and 2.3 mm, more preferably between 0.5 and 2 mm.

[0126] A base width BW of the respective protrusions 4a,5a preferably lies between 0.3 and 1.3 mm, more preferably between 0.5 and 1.0 mm. The height H preferably lies between 0.8 and 1.7 mm, more preferably between 1 and 1.5 mm.

[0127] The base portion B preferably extends to a height h1 of between between ⅓ to ½ of overall height H. Correspondingly, upper portion A may extend to a height h2 of between ⅔ to ½ of overall height H.

[0128] The projections 4a, 5a may comprise free ends 7a, 7b of progressively reducing dimensions to ensure a smoother transition with the surface 2a of the flange-like rim. The width r3-r2, r5-r4 and height H at these free ends 7a, 7b preferably diminish progressively towards circumferentially extending gaps 4b, 5b. In particular, the shape of these ends 7a, 7b may be slightly triangular or rounded when viewed from the top in direction of the flange-like rim as illustrated in FIG. 3. As a result, the forming of the projections is facilitated with lower risk of cracks or wrinkles.

[0129] FIGS. 5a and 5b are sectional side views according to direction B-B (FIG. 2) of a preferred embodiment of the sealing member 3 of the capsule 10 and an engagement member 21 of a beverage preparation machine 20 respectively before and after engaging with each other.

[0130] As shown in FIG. 5a, and in addition to the previous elements already described, the respective protrusions 4a,5a of the sealing member 3 are preferably hollow. Accordingly, the protrusions 4a,5a are not filled with material of the flange-like rim 2, but are formed by a contour of wall thickness t2. The respective protrusions 4a,5a thus preferably form a hollow body that is open to the lower surface 2b of the flange-like rim 2.

[0131] Due to the drawing process, the wall thickness t1 of the flange-like rim 2 may generally be slightly larger than the wall thickness t2 of the protrusions 4a,5a for the same reason, the wall thickness t1, t2 may generally be larger than the wall thickness tb of the base body 2 of the capsule.

[0132] The engagement member 21 of the dedicated beverage preparation machine 20 is preferably an essentially hollow bell-shaped engagement member 21 for receiving the capsule base body 1 therein. When the capsule 10 is placed into the beverage preparation machine 20, the engagement member 21 will be lowered onto the capsule 10 by means of a dedicated closing force F as indicated in FIG. 5a. The sealing surface 21a of the engagement member 21 may be an annular lower surface with rounded inner and outer circumferential edges. The front surface (or sealing surface) 21a comprises a radial thickness D which preferably lies between 0.8 and 1.2, more preferably between 0.9 and 1.1 mm.

[0133] The annular space 6 between the protrusions 4a,5a of the inner and outer series 4,5 of the sealing member 3 is designed for receiving the sealing surface 21a of the capsule engagement member 21 of the beverage preparation machine 20. The annular space 6 comprises a preferably flat annular bottom surface 6a which interconnects the neighboring protrusions 4a,5a. The annular bottom surface 6a extends to a radial distance respectively thickness d as described above. The distance d is preferably chosen such as to be equal to or slightly smaller than an annular radial thickness D of the sealing surface 21a of the engagement member 21. In a preferred embodiment, thickness d is chosen to be between 0.1 and 0.5, more preferably between 0.2 to 0.3 mm smaller than the annular radial thickness D of the sealing surface 21a.

[0134] The annular space 6 preferably widens from the bottom surface 6a towards the tip portions C of the neighboring protrusions 4a,5a. Thereby, the respective upper ends of the base portions B of neighboring protrusions 4a,5a are preferably distanced by a radial distance dl that is larger than the distance d at the bottom surface 6a. The distance dl is preferably chosen to be 0.2 to 0.3 mm larger than the radial thickness D of the sealing surface 21a of the engagement member 21.

[0135] When the engagement member 21 is lowered from the position shown in FIG. 5a onto the sealing member 3 by closing force F, the annular sealing surface 21a will engage in the annular space 6, thereby providing a fluid tight engagement between the sealing surface 21a and the neighboring arc-shaped protrusions 4a,5a of the sealing member 3.

[0136] In the circumferentially overlapping regions of the protrusions 4a, 5b (FIGS. 5a and 5b), the engagement of the sealing surface 21 may be completed both by the engagement of the outer sealing surface portion 21aa with the wall of the protrusions 5a of the outer series and/or by the engagement of the inner sealing surface portion 21ab with the wall of the protrusions 4a of the inner series. Additionally, the rounded tip portion C may be engaged by a correspondingly formed annular receiving groove E of the engagement member 21. Accordingly, an effective sealing engagement between the sealing member 3 and the engagement member 21 of the beverage preparation machine is obtained.

[0137] This is clearly visible in FIG. 5b in which the engagement member 21 fully engages with the inner and outer series 4,5 of arc-shaped protrusions 4a,5a. Indeed, the front surface 21a engage with an annular bottom surface 6a of the annular space 6 which interconnects the neighboring protrusions 4a,5a.

[0138] Additionally, the closing membrane 9 is preferably sealed on the annular bottom surfaces 2d and the outer annular surface 2b. Preferably, the annular bottom surface 2d between the inner and outer series 4,5 is not elevated or lowered relative to the outer annular surface 2b and/or the inner annular bottom surface 2d. preferably, the annular bottom surfaces 2d and the outer annular surface 2b are preferably substantially aligned.

[0139] As shown in FIGS. 5a and 5b, the closing membrane 9 is connected to an annular outer portion of the surface 2b of the flange-like rim. The closing membrane 9 may additionally be connected to intermediate annular surfaces 2d arranged between the outer annular surface 2b and the capsule base body 1. The closing membrane 9 is preferably an aluminum foil sealed to the flange-like rim 2.

[0140] At an outer peripheral edge 2c, the flange-like rim 2 may comprise a rollover edge 11 known in the present technical field.

[0141] FIG. 6a and FIG. 6b are sectional side views according to direction A-A of FIG. 2 of a preferred embodiment of the sealing member 3 of the capsule 10 and an engagement member 21 of a beverage preparation machine 20 respectively before and after engaging with each other.

[0142] The cross sections presented in FIGS. 6a and 6b are cross sections in which one of the bridging elements 8 extends between and connects protrusions 4a,5a.

[0143] The bridging element 8 presented in FIGS. 6a and 6b, extends between the protrusions 4a,5a of the inner and outer series 4,5 of the sealing member 3, and is designed for receiving the sealing surface 21a of the capsule engagement member 21 of the beverage preparation machine 20. The bridging element 8 comprises on its upper surface a preferably flat annular bottom surface 6b which interconnects the neighboring protrusions 4a,5a. The bridging element 8 extends to a radial distance dl as described above. The distance dl is preferably chosen such as to be equal to or slightly smaller than an annular radial thickness D of the sealing surface 21a of the engagement member 21. In a preferred embodiment, thickness dl is chosen to be between 0.1 and 0.5, more preferably between 0.2 to 0.3 mm smaller than the annular radial thickness D of the sealing surface 21a.

[0144] When the engagement member 21 is lowered from the position shown in FIG. 6a onto the sealing member 3 by closing force F, the annular sealing surface 21a will engage in the annular space 6 and will contact the bridging element 8. During engagement, the sealing surface 21 may deform the bridging element 8, thereby providing a fluid tight engagement between the sealing surface 21a and the capsule.

[0145] Additionally, the sealing surface 21a may engage with the neighboring arc-shaped protrusions 4a,5a of the sealing member 3 thereby provide.

[0146] In other words, the difference in diameter between the inner and outer series of arc-shaped protrusions 4,5 is such that the engagement member 21 of the coffee preparation machine 20 is intended to fit in the annular space 6 between the inner and outer series of arc-shaped protrusions 4,5 and to compress the bridging elements 8 positioned there between.

[0147] The combination of the interaction between engagement member 21 and the inner and outer series of arc-shaped protrusions 4,5, due to their slightly overlapping diameters, and of the engagement between engagement member 21 and bridging elements 8, by compression of the bridging elements 8 by the sealing surface 21a, generates the required tightness between the capsule and the enclosing member of the coffee machine needed for beverage extraction.

[0148] In detail, the engagement of the engagement member 21 with the side walls in the overlapping area of the inner and outer series of arc-shaped protrusions 4,5 will produce, mainly, a radial tightness between the capsule 10 and engagement member 21 and the engagement of the engagement member 21 with the bridging elements 8 between the arc-shaped protrusions 4a,5a will produce, mainly, tightness between capsule 10 and engagement member 21 for the potential water flowing in circumferential direction between the arc-shaped protrusions 4a,5a and the underneath sealing surface 21a of the engagement member 21.

[0149] The engagement between the sealing surface 21a and the bridging element 8 allow improving the performances, in terms of tightness, of the tightness generated by the arc-shaped protrusions 4a,5a alone.

[0150] Reference is now made to FIGS. 7a to 8b.

[0151] FIGS. 7a and 7b are sectional side views in direction D-D of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine respectively before and after engaging with each other.

[0152] FIGS. 8a and 8b are sectional side views in direction C-C of FIG. 2 of a preferred embodiment of the sealing member according to the invention and an engagement member of a beverage preparation machine, respectively before and after engaging with each other. These cross sections are outside the circumferentially overlapping regions of the protrusions.

[0153] As illustrated in these figures that are cross sections outside the circumferentially overlapping regions of the protrusions, the sealing engagement of the sealing surface 21a of the engagement member 21 may be limited to one of the sealing surface portions 21ab or 21aa respectively with the projections 4a of the inner series (FIG. 7a and 7b) or the projections 5a of the outer series (FIGS. 8a and 8b) respectively.

[0154] In the cross sections of FIGS. 7a and 7b, the engagement member 21 will only interact with the inner series of arc-shaped protrusions 4, and especially with sealing surface portion 21aa.

[0155] In the cross sections of FIGS. 8a and 8b, the engagement member 21 will only interact with the outer series of arc-shaped protrusions 5, and especially with sealing surface portion 21aa.

[0156] As the engagement member 21 is moved towards the flange-like rim 2 by pressure effect during closing and/or extraction, the sealing surface portions 21aa, 21ab may respectively deform the arc-shaped protrusions 4, 5 according to the cross section that is considered and increase the contact surface area with the protrusions accordingly.

[0157] In particular, as shown in FIGS. 7a and 7b, the radius rei of the position of the sealing surface portion 21ab of the engaging member 21 suitable to engage the projections 4a of the inner series is preferably chosen smaller than the outer radius r3 of protrusions 4. As shown in FIGS. 8a and 8b, the radius ree of the position of the sealing surface portion 21aa of the engaging member 21 suitable to engage the projections 5a of the inner series is preferably chosen larger than the radius r4 of the radial extension of the arc-shaped protrusions 5a. As a result, a sealing pressure is exerted about the whole circumference of the sealing surface 21a of the engagement member by the sealing member 3 thereby ensuring a sealing continuity.