CAPSULE, A SYSTEM FOR PREPARING A POTABLE BEVERAGE FROM SUCH A CAPSULE AND USE OF SUCH A CAPSULE IN A BEVERAGE PREPARATION DEVICE

Abstract

A capsule containing a substance for the preparation of a potable beverage. The capsule comprises an aluminum capsule body having a side wall and an outwardly extending flange and a sealing member at the outwardly extending flange for providing a fluid sealing contact with an enclosing member of a beverage preparation device. The beverage preparation device comprises an annular element having a free contact end which may be provided with a plurality of radially extending open grooves. The sealing member is integral with the outwardly extending flange and comprises at least one projection projecting from the outwardly extending flange. The projection comprising a projection top and is configured such that its projection top exerts a radial force on the free contact end of the annular element if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device.

Claims

1-81. (canceled)

82. System for preparing a potable beverage from a capsule using a fluid supplied under pressure into the capsule comprising: a beverage preparation device comprising an enclosing member for receiving the capsule, wherein the enclosing member comprises fluid injection means for supplying fluid under pressure into the capsule, wherein the beverage preparation device further comprises a closing member, such as an extraction plate, for closing the enclosing member of the beverage preparation device, wherein the enclosing member of the beverage preparation device further comprises an annular element having a central annular element axis and a free contact end, said free contact end of the annular element optionally being provided with a plurality of radially extending open grooves; and a capsule containing a substance for the preparation of a potable beverage by extracting and/or dissolving the substance by means of supplying a fluid under pressure into the capsule, wherein the capsule comprises an aluminum capsule body having a central capsule body axis, said aluminum capsule body being provided with a bottom, a side wall and an outwardly extending flange, the capsule further comprising an aluminum cover attached to the outwardly extending flange, the cover hermetically closing the capsule, wherein the capsule further comprises a sealing member at the outwardly extending flange for providing a fluid sealing contact with the enclosing member of the beverage preparation device if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of the closing member of the beverage preparation device, such that the outwardly extending flange of the capsule and at least a portion of the sealing member of the capsule are sealingly engaged between the enclosing member and the closing member of the beverage preparation device, characterized in that, the sealing member is integral with the outwardly extending flange and comprises at least one projection projecting from the outwardly extending flange, said at least one projection comprising a projection top, and wherein the at least one projection is configured such that its projection top exerts a radial force on the free contact end of the annular element if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of the closing member of the beverage preparation device, wherein the sealing member comprises a further projection projecting from the outwardly extending flange and a plateau between said two projections, wherein the distance between the two projections is such that the free contact end of the annular element is positioned between the two projections if the capsule is positioned in the enclosing member and as the enclosing member is closed by means of the closing member, wherein the sealing structure and the remainder of the capsule body are made of the same plate material, and wherein the enclosing member and the projections are arranged such that, when the enclosing member and/or the closing member is moved towards the other with the sealing member in-between, the free contact end of the annular element may first contact the first one of the two projections and subsequently contacts the second one of the two projections.

83. System according to claim 82, wherein a first one of the two projections projects further from a base portion of the outwardly extending flange, to which base portion the cover is attached, than a second one of the two projections.

84. System according to claim 83, wherein the first one of the two projections is a radially inner one of the two projections.

85. System according to claim 82, wherein the sealing member comprises an annular trough between an inner one of the projections and the side wall, the annular trough having a bottom axially spaced from the base portion to which base portion the cover is attached.

86. System according to claim 82, wherein the plateau is axially spaced from the cover.

87. System according to claim 85, wherein the bottom of the annular through is at a first axial distance from the cover and the plateau is at a second axial distance from the cover, said second axial distance being larger than said first axial distance.

88. System according to claim 87, wherein the sealing member is deformable such that, in use, closure of the enclosing member deforms the side wall to cause the bottom of the annular trough to be brought substantially in contact with the cover.

89. System according to claim 87, wherein the inner one of said two projections is shaped such that it is bent open if the sealing member is deformed such that the plateau contacts the cover.

90. System according to claim 82, wherein a radially outer one of said two projections has a greater stiffness against radial outward deformation than the inner one of said two projections.

91. System according to claim 82, wherein a first one of the two projections has an extreme top end extending around the capsule axis at a diameter of 29.2 to 29.8 mm and wherein a second one of the two projections has an extreme top end extending around the capsule axis at a diameter of 31.9 to 32.4 mm.

92. System according to claim 82, wherein an outer one of said two projections has a generally inwardly facing surface portion extending at an enclosed angle of less than 8° and preferably less than 6° or less than 4° to the capsule body axis.

93. System according to claim 82, wherein the distance between the two projections is such that the free contact end of the annular element is contacted by the two projections if the capsule is positioned in the enclosing member and the enclosing member is closed by means of the closing member.

94. System according to claim 82, wherein the two spaced projections and the plateau are arranged such that the free contact end of the annular element is contacted by the plateau if the capsule is positioned in the enclosing member and the enclosing member is closed by means of the closing member.

95. System according to claim 82, wherein the capsule comprises a bearing for the enclosing member if the capsule is positioned in the enclosing member and the enclosing member is closed by means of the closing member, said bearing enclosing at least a portion of the free contact end of the annular element and said bearing being formed by the two projections and the plateau there between.

96. System according to claim 82, wherein, seen in cross-section along a plane through the capsule body axis, the plateau has a sloping section forming a transition to the outer one of said two projection, wherein the sloping section constitutes a relatively straight section between more curved sections.

97. System according to claim 96, wherein the sloping section is oriented at an enclosed angle of at least 10° and more preferably at least 20° and at most and 60° and more preferably at most 50° relative to the cover.

98. System according to claim 82, wherein the plateau is substantially flat.

99. System according to claim 82, wherein the plateau comprises a curved portion, the plateau preferably being V-shaped.

100. System according to claim 82, wherein an outer one of said two projections is shaped to roll and buckle radially outwards if compressed in axial direction, while in contact with an outwardly facing surface of a free end of the annular element positioned between the two projections.

101. System according to claim 82, wherein a transition from the outer one of said two projections to a radially outwardly projecting flange of the a base portion to which the cover is attached has an internal radius of less than 0.15 mm and preferably less than 0.12 mm, a radially outer wall of said outer one of said two projections being oriented at an enclosed angle relative to the capsule body axis of less than 8° and more preferably less than 6°.

102. System according to claim 82, wherein the at least one projection comprises a projection side wall which is inclined with regard to the outwardly extending flange of the aluminum capsule body, said projection side wall being configured such that it is deformed easily if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of the closing member of the beverage preparation device.

103. System according to claim 82, wherein said free contact end of the annular element has a first circumferential surface portion contacting said first projection, if the capsule is positioned in the enclosing member and as the enclosing member is closed by means of the closing member, and a second circumferential surface portion contacting said second projection, if the capsule is positioned in the enclosing member and as the enclosing member is closed by means of the closing member, wherein said radially extending open grooves are deeper in said first surface portion than in said second surface portion or said radially extending open grooves are absent in said second surface portion.

104. System according to claim 96, and wherein the annular element is arranged for deformation of the sloping section.

105. System according to claim 82, wherein the annular element has outer and inner ridges and wherein the outer one of said two projections is arranged to be deformed between said outer and inner ridges if the sealing member is clamped between the enclosing member and the closing member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention will now be further elucidated by means of, non-limiting, examples referring to the drawing, in which:

[0045] FIG. 1 shows a schematic representation of an embodiment of a system according to the invention;

[0046] FIG. 2 in a perspective view shows an embodiment of a beverage preparation device of a system according to the invention showing the free contact end of the enclosing member of the beverage preparation device with the plurality of radially extending open grooves;

[0047] FIG. 3A in cross section shows an embodiment of a capsule according to the invention before use;

[0048] FIG. 3B shows an enlarged detail of a the capsule of FIG. 3A showing the outwardly extending flange and the sealing member;

[0049] FIG. 3C shows an enlarged detail of the outwardly extending flange of the capsule in FIGS. 3A and 3B after use;

[0050] FIG. 4A shows a first embodiment of a sealing member at the outwardly extending flange of a capsule according to the invention;

[0051] FIG. 4B shows a second embodiment of a sealing member at the outwardly extending flange of a capsule according to the invention;

[0052] FIG. 4C shows a third embodiment of a sealing member at the outwardly extending flange of a capsule according to the invention;

[0053] FIG. 4D shows a fourth embodiment of a sealing member at the outwardly extending flange of a capsule according to the invention;

[0054] FIG. 4E shows a fifth embodiment of a sealing member at the outwardly extending flange of a capsule according to the invention;

[0055] FIG. 4F shows a sixth embodiment of a seal member at the outwardly extending flange of a capsule according to the invention;

[0056] FIG. 4G shows a seventh embodiment of a seal member at the outwardly extending flange of a capsule according to the invention;

[0057] FIGS. 5A and 5B are schematic representations of successive stages of deformation of the seventh embodiment of a seal member at the outwardly extending flange of a capsule according to the invention if the capsule is positioned in the enclosing member of the beverage preparation device and as the enclosing member is closed by means of a closing member of the beverage preparation device; and

[0058] FIG. 6 is a schematical cross-section view of a deformed flange portion and a portion of an enclosing member where a bridge is present between inner and outer rims of a free end of the enclosing member.

[0059] In the figures and the following description, like reference numerals refer to like features.

DETAILED DESCRIPTION

[0060] FIG. 1 shows a schematic representation, in cross sectional view, of an embodiment of a system 1 for preparing a potable beverage from a capsule using a fluid supplied under pressure into the capsule. The system 1 comprises a capsule 2, and a beverage preparation device 4. The device 4 comprises enclosing member 6 for holding the capsule 2. The device 4 further comprises a closing member, such as an extraction plate, 8 for supporting the capsule 2.

[0061] In FIG. 1 a gap is drawn between the capsule 2, the enclosing member 6 and the extraction plate 8 for clarity. It will be appreciated that, in use, the capsule 2 may lie in contact with the enclosing member 6 and the extraction plate member 8. Commonly, the enclosing member 6 has a shape complementary to the shape of the capsule 2. The beverage preparation device 4 further comprises a fluid injection means 10 for supplying an amount of a fluid, such as water, under a pressure in the range of 6-20 bar, preferably between 12 and 18 bar, to the exchangeable capsule 2.

[0062] In the example shown in FIG. 1, the exchangeable capsule 2 comprises an aluminum capsule body 12 having a central capsule body axis 12A and an aluminum cover 14. In the present context, the meaning of ‘aluminum’ is understood to also include aluminum alloy. In this example, the aluminum capsule body 12 comprises a side wall 16, a bottom 18 closing the side wall 16 at a first end, and a outwardly extending flange 20 extending outwardly of the circumferential wall 16 at a second end opposite the bottom 18. The side wall 16, the bottom 18 and the cover 14 enclose an inner space 22 comprising a substance for the preparation of a potable beverage by extracting and/or dissolving the substance. Preferably the substance is an extractable product for the preparation of a potable beverage, the extractable product preferably being 5-20 grams, preferably 5-10 grams, more preferably 5-7 grams of roasted and ground coffee for the preparation of a single beverage. The capsule is initially sealed, i.e. is hermetically closed prior to use.

[0063] The system 1 of FIG. 1 comprises bottom piercing means 24 for piercing the bottom 18 of the capsule 2 for creating at least one entrance opening 25 in the bottom 18 for supplying the fluid to the extractable product through the entrance opening 25.

[0064] The system 1 of FIG. 1 further comprises cover piercing means 26, here embodied as protrusions of the closing member 8, for piercing the cover 14 of the capsule 2. The cover piercing means 26 may be arranged to tear the cover 14 once a (fluid) pressure inside the inner space 22 exceeds a threshold pressure and presses the cover 14 against the cover piercing means 26 with sufficient force. The aluminum cover 14 thus is arranged to tear open on the closing member 8 of the beverage preparation device under the influence of fluid pressure in the capsule.

[0065] The capsule 2 further comprises a sealing member 28 integral with the outwardly extending flange, in FIGS. 1, 3A and 3B indicated as a general box but more detailed described with regard to FIG. 4, which sealing member 28 is arranged for providing a fluid sealing contact with the enclosing member 6 if the capsule 2 is positioned in the enclosing member 6 and the enclosing member 6 is closed by means of the extraction plate 8, such that the outwardly extending flange 20 of the capsule 2 and at least a portion of the sealing member 28 are sealingly engaged between the enclosing member 6 and the extraction plate 8. This means that a fluid sealing contact between the sealing member and the free contact end is established.

[0066] As shown in FIG. 2 the enclosing member 6 of the beverage preparation device comprises an annular element 41 having a central annular element axis 41A and a free contact end 30. The free contact end 30 of the annular element 41 is provided with a plurality of radially extending open grooves 40. The plurality of radially extending open grooves 40 are uniformly spaced relative to each other in tangential direction of the free contact end 30 of the annular element 41. The longest tangential width of each groove 40 is 0.9-1.1 mm, preferably 0.95 to 1.05 mm, more preferably 0.98 to 1.02 mm, wherein a maximal height of each groove 40 in an axial direction of the enclosing member 6 is 0.01-0.09 mm, preferably 0.03 to 0.07 mm, more preferably 0.045 to 0.055 mm, and most preferred 0.05 mm. The number of grooves 40 lies in the range of 90 to 110, preferably 96. Usually, the radial width of the free end at the location of the grooves is 0.05-0.9 mm, more specifically 0.2-0.7 mm, more specifically 0.3-0.55 mm.

[0067] An embodiment of a capsule according to the invention is shown more detailed in FIGS. 3A and 3B. In the shown embodiment the outer diameter ODF of the outwardly extending flange 20 is larger than the diameter DB of the bottom 18 of the capsule 2. In the shown embodiment the outer diameter ODF of the outwardly extending flange 20 is approximately 37.1 mm and the diameter DB of the bottom 18 is about 23.3 mm. The thickness of the aluminum capsule body 12 is such that it is deformed easily if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device, preferably the thickness of the aluminum capsule body is 100 micrometer, but in other embodiments the thickness can be 20 to 200 micrometer.

[0068] In the shown embodiment, the wall thickness of the aluminum cover 14 is 39 micrometer. The wall thickness of the aluminum cover 14 is preferably smaller than the thickness of the aluminum capsule body 12.

[0069] The side wall 16 of the aluminum capsule body 12 has a free end 42 opposite the bottom 18. The inner diameter IDF of the free end 42 of the side wall 16 of the aluminum capsule body 12 is about 29.5 mm. The outwardly extending flange 20 extends from that free end 42 in a direction at least substantially transverse to the central capsule body axis 12A. The outwardly extending flange 20 comprises a curled outer edge 43 which is beneficial for obtaining a seal between the capsule and the enclosing member. In the shown embodiment the curled outer edge 43 of the outwardly extending flange 20 has a largest dimension of about 1.2 millimeter. The distance DIF between the free end 42 of the side wall 16 of the aluminum capsule body 12 and an inner edge 43A of the curled outer edge 43 is about 2.7 mm, while the distance DOF between the free end 42 of the side wall 16 of the aluminum capsule body 12 and an outermost edge 43B of the outwardly extending flange 20 is about 3.8 millimeter. The radius about the central capsule body axis of the inner edge 43A of the curled outer edge 43 is preferably at least 32 mm.

[0070] As shown in FIGS. 3A and 3B the sealing member 28 is positioned between the free end of the side wall 16 of the aluminum capsule body 12 and the inner edge 43A of the curled outer edge 42 of the outwardly extending flange. The sealing member 28 is indicated as a general box, but will be described in more detail below. Irrespective of the embodiment of the sealing member 28 the height of the sealing member portion to be contacted first by the free end of the enclosure member when the enclosure member is closed is at least about 0.1 mm, more preferably at least 0.2 mm and most preferably at least 0.8 mm and at most 3 mm, more preferably at most 2 mm and most preferably at most 1.2 mm for providing a correct seal.

[0071] As can be seen from FIG. 3A the aluminum capsule body 12 is truncated. In the embodiment shown, the side wall 16 of the aluminum capsule body 12 encloses an angle A with a line transverse to the central capsule body axis 12A of about 97.5°. The bottom 18 of the aluminum capsule body 12 has a largest inner diameter DB of about 23.3 mm. The bottom 18 of the aluminum capsule body 12 is also truncated, and in the shown embodiment has a bottom height BH of about 4.0 mm. The bottom 18 further has a generally flat central portion 18A opposite the cover 14, which central portion 18A has a diameter DEE of about 8.3 mm and in which central portion 18A the entrance opening(s) 25 may be made. The entrance openings may also be made in the truncated portion between the central portion 18A and the side wall 16. The total height TH of the aluminum capsule body 12 of the capsule is about 28.4 mm.

[0072] The system 1 shown in FIG. 1 is operated as follows for preparing a cup of a potable beverage, in the present example coffee, wherein the substance is roasted and ground coffee.

[0073] The capsule 2 is placed in the enclosing member 6. The extraction plate 8 is brought into contact with the capsule 2. The bottom piercing means 24 pierce the bottom 18 of the capsule 2 for creating the entrance openings 25. The fluid, here hot water under pressure, is supplied to the extractable product in the inner space 22 through the entrance openings 25. The water will wet the coffee grounds and extract the desired substances to form the coffee beverage.

[0074] During supplying the water under pressure to the inner space 22, the pressure inside the capsule 2 will rise. The rise in pressure will cause the cover 14 to deform and be pressed against the lid piercing means 26 of the extraction plate. Once the pressure reaches a certain level, the tear strength of the cover 14 will be surpassed and the cover 14 will rupture against the lid piercing means 26, creating exit openings. The prepared coffee will drain from the capsule 2 through the exit openings and outlets 32 (see FIG. 1) of the extraction plate 8, and may be supplied to a container such as a cup (not shown).

[0075] The system 1 is arranged such that prior to or at the start of brewing, the free end 30 of the enclosing member 6 exerts a force F1 on the sealing member 28 of the capsule 2 to provide a fluid sealing contact between the outwardly extending flange 20 of the capsule 2 and the enclosing member 6 of the beverage preparation device, wherein F1 is in the range of 30-150 N preferably 40-150 N, more preferably 50-100 N, when the fluid pressure P1 in the enclosing member of the beverage preparation device outside the capsule is in the range of 0.1-4 bar, preferably 0.1-1 bar. During brewing, the free end 30 of the enclosing member 6 exerts a force F2 on the sealing member 28 of the capsule 2 to provide a fluid sealing contact between the outwardly extending flange 20 of the capsule 2 and the enclosing member 6, wherein the force F2 is in the range of 500-1500 N, preferably in the range of 750-1250 N, when the fluid pressure P2 in the enclosing member 6 of the beverage preparation device outside the capsule 2 is in the range of 6-20 bar, preferably between 12 and 18 bar. In the shown embodiment the free contact end of enclosing member 6 can move relative to the extracting plate 8 under the effect of the pressure of the fluid in the enclosing member 6 device towards the extraction plate 8 for applying the maximum force F2 between the outwardly extending flange 20 and the free end 30 of the enclosing member 6. This movement can take place during use, i.e. in particular at the start of brewing and during brewing. The enclosing member 6 has a first part 6A and a second part 6B wherein the second part comprises the free contact end 30. The second part 6B can move relative to the first part 6A between a first and second position. The second part 6B can move from the first positon towards the second position in the direction of the closing member 8 under the influence of fluid pressure in the enclosing member 6. The force F1 as discussed above may be reached if the second part 6B is in the first position with a fluid pressure P1. The force F2 as discussed above may be reached if the second part 6B is moved towards the second position under the influence of the fluid pressure P2 in the enclosing member 6.

[0076] As a result of the force applied the sealing member 28 of the capsule according to the invention undergoes a plastic deformation and closely conforms to the grooves 40 of the free contact end 30 and thus provides a fluid sealing contact between the enclosing member 6 and the capsule 3 at a relatively low fluid pressure during start up of brewing but also provides a fluid sealing contact at the much higher fluid pressure in the enclosing member outside the capsule during brewing. This close conformation to the grooves 40 of the enclosing member is indicated in FIG. 3C which shows the capsule 2 of the invention after use, and which clearly indicates that the outwardly extending flange 20 comprises deformations 40′ which conform to the grooves 40 of the enclosing member.

[0077] Now exemplary embodiments of a sealing member 28 at the outwardly extending flange 20 of the capsule 2 according to the invention will be described in more detail with regard to FIG. 4.

[0078] FIG. 4A shows a first embodiment of a sealing member 28 forming an additional bearing at the outwardly extending flange 20 of a capsule 2 according to the invention. The sealing member and the remainder of the capsule body are made of the same plate material. The sealing member 28 comprises two spaced projections 50 and 51, each projecting axially from a base portion of the outwardly extending flange 20, to which base portion the cover 14 is attached, in a direction away from the cover 14. A plateau 52 is present between the two projections 50 and 51. The distance between the two projections 50 and 51 is such that the free contact end of the annular element 6 is squeezed between converging surfaces of the two projections 50 and 51 if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device. In the embodiment shown in FIG. 4A the plateau is positioned at a distance above the portion of the outwardly extending flange 20 between the sealing member 28 and the curled edge 43 and is substantially flat. The distance between the two projections 50 and 51 is further such that the free contact end of the annular element is contacted by the two projections 50 and 51 if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device. Further, the two spaced projections 50, 51 and the plateau 52 are arranged such that the free contact end of the annular element is contacted by the plateau if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device. As can be seen in FIG. 4A each projection 50, 51 comprises a projection side wall which is inclined with regard to the outwardly extending flange 20 of the aluminum capsule body. The projection side wall is configured such that it is deformed easily if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device.

[0079] FIG. 4B shows a second embodiment of a sealing member 28 at the outwardly extending flange 20 of a capsule according to the invention. When compared with FIG. 4A the following differences are noted. Each projection 50, 51 now comprises a projection side wall which is transverse with regard to the outwardly extending flange 20 of the aluminum capsule body. Further, in this second embodiment the plateau 52 is curved, preferably conforming to the shape of the free contact end of the annular element 6.

[0080] FIG. 4C shows a third embodiment of a sealing member 28 at the outwardly extending flange 20 of a capsule according to the invention, which together with the side wall 16 of the aluminum capsule body forms an additional bearing for the enclosing member. The shown sealing member 28 comprises a projection 53 projecting from the outwardly extending flange 20 and an inclined, substantially flat plateau 52 between a rounded topmost end portion of the projection 53 and the side wall 16 of the aluminum capsule body. In this embodiment the bearing is formed by the projection 53, the plateau 52 and the side wall 16 of the aluminum capsule body. The distance between the top of the projection 53 and the side wall 16 is such that the free contact end of the annular element 6 is enclosed by the projection 53 and the side wall 16 of the aluminum capsule body if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device. In particular the distance between the projection 53 and the side wall 16 of the aluminum capsule body is such that the free contact end of the annular element 6 is contacted by the projection 53 and the side wall 16 and in the shown embodiment also the plateau 52 of the aluminum capsule body if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device.

[0081] FIG. 4D shows a fourth embodiment of a sealing member 28 at the outwardly extending flange 20 of a capsule according to the invention, which together with the side wall 16 of the aluminum capsule body forms an additional bearing for the enclosing member. When compared with FIG. 4C the following differences are noted. In this fourth embodiment the plateau 52 is curved, and comprises a curved portion and also a flat portion which is situated at the same level as the portion of the outwardly extending flange 20 between the projection 53 and the curved edge 43. The curved portion preferably conforms to the shape of the free contact end of the annular element 6. FIG. 4E shows a fifth embodiment of a sealing member 28 at the outwardly extending flange 20 of a capsule according to the invention, which together with the side wall 16 of the aluminum capsule body forms a bearing for the enclosing member. When compared with FIG. 4D the following difference is noted. In this fifth embodiment the flat portion of the plateau 52 is situated at a distance above the portion of the outwardly extending flange 20 between the projection 53 and the curved edge 43. The distance between 2 the projection 53 is preferably 0.9-1.25 mm, which allows the free end of the closing member of widely used and commercially available beverage preparation devices (such as the Citiz, Lattisima, U, Maestria, Pixie, Inissia and Essenza) to be reliably squeezed against the projections 53 with the side wall 16 in close proximity thereto.

[0082] In the embodiments shown in FIGS. 4C to 4E the projection 53 comprises an outer projection side wall 54 which is transverse to the portion of the outwardly extending flange between the projection 53 and the curled edge 43, but in other embodiments this outer projection side wall 54 can be inclined with regard to the portion of the outwardly extending flange 20.

[0083] In all the embodiments shown in FIGS. 4A to 4E each of the projections comprises a projection top constituting a portion of the projection, for instance a half, a third or a quarter of the projection, that is axially most distal from the base portion of the flange 28 to which the cover 14 is attached. At least one projection but preferably all projections forming the additional bearing is/are configured such that its projection top exerts a radial force on the free contact end of the annular element 6 if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device.

[0084] FIG. 4F shows a sixth embodiment of a seal member 28 at the outwardly extending flange 20 of a capsule according to the invention. When compared with e.g. FIG. 4B the following differences are noted. In this sixth embodiment the plateau 52 is V-shaped, with the bottom of the V-shaped being at the same level as the base portion of the outwardly extending flange 20 between the outer projection 51 and the curled edge 43. In this manner no bearing for the free contact end of the annular member 6 is formed, but the projection top of the inner projection 50 exerts a radial force direct outwardly on the free contact end of the annular element 6 and the projection top of the outer projection 51 exerts a radial force direct inwardly on the free contact end of the annular element 6 if the capsule is positioned in the enclosing member of the beverage preparation device and the enclosing member is closed by means of a closing member of the beverage preparation device. In this manner the free contact end is squeezed by the sealing member 28 thereby providing a satisfactory seal.

[0085] In capsules in which the sealing structure 28 has projections 50, 51 and a plateau or through 52 in between, as by way of example shown in FIGS. 4A, 4B, and 4F, the center of the plateau or through 52, which extends circumferentially around the center axis of the capsule, preferably has a diameter of 29-33 mm, more preferably 30.0-31.4 mm and most preferably 30.3-31.0 mm, so that (seen in radial cross-section) the free end of the closing member of widely used and commercially available beverage preparation devices (such as the Citiz, Lattisima, U, Maestria, Pixie, Inissia and Essenza) lands accurately centered between the projections 50, 51 and the squeezing effect is evenly distributed over the inner and outer projections 50, 51. For effective squeezing in such apparatuses, the distance between projections 50, 51 is preferably 0.9-1.25 mm.

[0086] FIG. 4G shows a seventh embodiment of a seal member 28 at the outwardly extending flange 20 of a capsule according to the invention. As also shown in FIG. 2, the enclosing member 6 of the beverage preparation device has an annular element 41 having a free contact end 30 with a plurality of radially extending open grooves 40 of which some are shown in FIG. 4G.

[0087] As in the examples shown in FIGS. 4A, 4B and 4F, the sealing member 28 has two spaced projections 50 and 51, each projecting axially from a base portion 23 of the outwardly extending flange 20, to which base portions 21, 23 the cover 14 is attached, in a direction away from the cover 14. As in the example shown in FIG. 4F, a plateau 52 having a rounded bottom is located between the two projections 50 and 51.

[0088] A difference compared with the examples shown in FIGS. 4A, 4B and 4F is that, in the example shown in FIG. 4G, a first one of the two projections 51 projects further from a base portion 23 of the outwardly extending flange 20 than a second one of the two projections 50.

[0089] Another difference is that a bottom 56 of an annular trough 55 between the inner projection 51 and the side wall 16 is axially spaced from the base portion 23 to which base portion the cover is attached. Preferably, the axial distance from the bottom 56 to the cover is smaller than the axial distance from the plateau 52 to the cover.

[0090] When the enclosing member 6 and/or the closing member 8 is moved towards the other with the sealing member 28 of the capsule in between, the free contact end 30 of the annular element 41 may first contact the first one of the two projections 51 and subsequently contacts the second one of the two projections (FIG. 5A).

[0091] If and when the free contact end 30 of the annular element 41 contacts the inner one of the two projections 51, the capsule is centered relative to the enclosing member 6. Moreover, if the inner one of the two projections 51 is radially too far to the outside, for instance locally due to non-circularity or off-centered positioning of the capsule, or generally due to the free contact area having a relatively small diameter, the free contact end urges the inner one of the two projections 51 radially inwardly. The outer one of the two projections is thereby entrained inwardly, so that a reliable firm sealing pressure is exerted onto the outer one of the two projections 50 in spite of the relatively small deformability of that outer projection 51 due to its smaller height. The relatively large stiffness of the outer one of the two projections 50, allows a large contact force to be exerted as it is deformed (FIG. 5B), the relatively high counter pressure provides a particularly reliable seal with high pressure resistance. Also, the outer one of the two projections 50 is then urged outwardly, which load is counteracted by hoop stress in the outer one of the two projections, which is evenly distributed circumferentially so that an evenly distributed sealing pressure is achieved.

[0092] As can also be seen from FIG. 5a, the free contact end 30 of the annular element 41 has an inner circumferential surface portion 71 contacting the inner projection 51 and an outer circumferential surface portion 70 contacting the outer projection 50. The radially extending open grooves 40 are deeper in the inner surface portion 71 than in the outer surface portion 70 or the grooves may be absent in the outer surface portion 70. Thus, the smaller, relatively stiff outer projection 50 is firmly and accurately pressed against the relatively smooth outer surface portion 70 of the free contact end 30.

[0093] The distance between the two projections 50 and 51 is such that ultimately (FIGS. 5A and 5B) the free contact end 30 of the annular element 41 is squeezed between converging surfaces of the two projections 50 and 51 when the enclosing member is fully closed by means of the closing member.

[0094] The plateau 52 is axially spaced from the cover 14. As illustrated by FIG. 5B, this allows the plateau 52 between the projections 50, 51 to be displaced in the direction of relative movement of the free end 30 of the annular element 41 as the enclosing member 6 is closed, urging the projections 50, 51 to be tilted and roll off inwardly against the free end 30 of the annular element 41 as the enclosing member 6 is closed. This increases the radial sealing pressure that is exerted (in addition to the axial closing pressure), so that an increased sealing pressure is available for providing a satisfactory seal.

[0095] More specifically, three stages may be distinguished if the sealing member of the rim according to FIGS. 4G, 5A, 5B and 6 is clamped between the annular element 41 of the enclosing member 6 and the closing member 8.

[0096] In the first stage contact between the annular element 41 and the sealing member 28 is established, where necessary under guidance of the inner projection 51 as described above and an initial seal is created between a generally inwardly facing surface portion of the outer projection 50 and an outer surface portion 70 of the free end 30 of the annular element 41. The radial location of this inwardly facing surface portion of the outer projection 50 and the local radius of curvature of the outer projection 50 is arranged to ensure that the faces contacting each other are oriented almost vertically. This allows a very strong wedging effect to be achieved, so that a very small vertical closing force results in very large horizontal contact pressures. These large horizontal forces are exerted with little deformation of the outer projection 50, because the reaction forces generated by the surface contact are contained mainly by hoop stress in the outer projection 50. Also, such hoop stresses are largely independent of the remainder of the sealing member 28, so that high stiffness for exerting a large sealing force can be combined with flexibility to accommodate to tolerances and misplacement of the capsule.

[0097] Because the bottom 56 of the annular trough, and accordingly the inner foot of the inner projection stands off from the cover friction and stiffness in the lateral directions are reduced and the sealing member 28 has a high degree of flexibility to accommodate misalignment and tolerance effects without undue distortion of the sealing faces. This also contributes to maintain the almost vertical orientations of the contacting faces even if misalignment and tolerances are accommodated to by lateral displacement of the contacting face of the sealing member 28.

[0098] In the second stage, the closure and further compression of the brew chamber onto the sealing ring is supported by the build-up of hydraulic pressure. As the compressive force builds, the bottom 56 of the annular trough 55 is pushed downwards by the mechanical and hydraulic loading and the whole sealing member pivots about an outer lower end 57 of the outer projection 50 until the bottom 56 of the annular trough 55 touches the cover (FIG. 5B). This pivoting movement results in both a ‘rigid body’ type motion of the sealing member 28 as well as deformation of the sealing member shape, both factors result in addition contact pressure being transferred to the primary sealing face. Since much of the deformation occurs plastically, the contact region conforms effectively to sealing area and allows some misalignment and manufacturing tolerances to be accommodated.

[0099] In the third stage, a further increase of the axial (here vertical) force causes further deformation of the sealing member 28 (FIG. 5B). In the present embodiment a reliably very leak-tight seal at a high pressure drop at high contact pressure is obtained by deformation of a sloping section 58 forming a transition from the outer projection 50 to the plateau, which section 58 constitutes a relatively straight section between more curved sections of the plateau 52 and the outer projection 50. Such deformation results in a particularly high contact pressure along a narrow line between the sealing member 28 and the outer surface portion 70 of the free end 30 of the annular element 41.

[0100] For obtaining an effective sealing, it is further advantageous that the outer projection 50 is wedged and thereby deformed between outer and inner ridges 59, 60 of the annular element 41.

[0101] As is shown in FIG. 5B, the inner projection 51 is bent open as the sealing member 8 is deformed, so that pulling away of sealing member material towards the bottom 56 of the annular member 55 and associated contact pressure relief is counteracted.

[0102] In particular in connection with the final mutual displacement of the annular element 41 and the sealing member 28, a particular issue is that most annular elements have one or more bridges 61 (FIG. 6) between outer and inner ridges 59, 60 of the annular element 41. Such bridges 61 constitute an interruption of an annular head space 62 into which the outer projection 50 is wedged during the third stage. Leakage in particular at the transitions where, in circumferential sense, the bridge begins and ends is diminished since the outer projection is shaped to roll and buckle radially outwards, so that excess sealing member material is locally displaced away from the seal between the outer projection 50 and the annular element 41, thereby reducing interference with this seal and allowing a substantially continuous seal along a line passing underneath the bridge 61.

[0103] In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as set forth in the appended claims.