Scope of the invention This invention relates to a capsule intended to receive a substance for the preparation of a beverage when the capsule is placed in a machine of the coffee 5 or infusion machine type in order to be held there by a piston as extracting liquid passes through the capsule and the substance which it contains, the capsule having a perforated base and a side wall wholly inscribed within a frustoconical shape and a rim which receives a 10 lid after the capsule has been filled with the substance. State of the art For many decades (1970) it has been known that beverages such as coffee can be prepared using machines 15 in which a capsule or unit doser containing ground coffee is placed. The capsule is then immobilised in the machine by a piston and water at high temperature and high pressure passes through it through holes produced when the capsule is placed in the machine or 20 through perforations which have previously been made in the capsule. In some cases the capsule is perforated and distributed in a sealed envelope which is opened when the capsule is placed in the machine. By way of example, such capsules are known in 25 particular from documents EP 0 512 148 of the 10.05.1991 and EP 512 468 of the 04.05.1992. These known capsules of the type described above have a cup shape with a base and a substantially frustoconical side wall ending in a circular rim at the 30 large end of the frustoconical shape. The circular rim receives a lid which is welded to the rim after the capsule has been filled with the substance used to 18 SEP 2013 - 2 prepare the beverage. Known capsules are hermetically sealed to ensure that the substance is preserved. There are also pre-perforated but empty capsules which the user fills with coffee of his choice 5 and then seals with a lid so that the capsules can be placed in the machine. In this way he can prepare a series of capsules which he will use in the short term. There are also filled capsules with a pre perforated base which are packed separately in a sealed 10 packaging to ensure the quality and freshness of the substance present in the capsule. But known capsules have sealing problems and give rise to risks that the capsules will deform when hot pressurised liquid passes through them, as a result 15 of which they can become jammed in the machine or do not make a leaktight seal with the piston with the result that pressurised hot water at least partly bypasses the capsule without passing through the substance within it. 20 Object of the invention The object of this invention is to overcome the disadvantages of known solutions and to provide a capsule holding a substance such as coffee for the preparation of a beverage which will be both very rigid 25 and allow the hot pressurised water to be well distributed as it passes through the capsule, avoiding any defect in the seal in the capsule's position in the machine and the risk of bypassing by the pressurised water. 30 Description and advantages of the invention For this purpose the invention relates to a perforated capsule of the type described above, characterised in that 8 SEP 2013 - 3 - the substantially frustoconical side wall has a main part beneath the rim comprising a main frustoconical portion and a portion close to the base of cylindrical shape which joins the main frustoconical 5 portion through a joining frustoconical portion and joins the base through a stiffening frustoconical portion, together with an internal surface provided with radial and longitudinal stiffening ribs, and - the perforated base is stiffened through a circular 10 rib pierced with holes projecting towards the interior of the capsule. The structure of the peripheral wall comprising different portions and its combination with the rib stiffened base having a central portion and a ring 15 ensure good distribution of the stresses brought about through the sudden arrival of very hot pressurized water, particularly against the base and then against the walls of the capsule. The stiffening rib at the base of the capsule 20 ensures that the capsule does not deform when the highly pressurised hot water arrives, as the holes in the perforated base allow the pressurised water to be well distributed within the capsule and bring about maximum extraction of the substance as the water passes 25 through. This indeformability of the base at the moment when the pressurised water arrives also ensures that the rim of the capsule between the grid of the machine and the edge of the machine's piston does not deform, avoiding the leakage of pressurised water which would 30 run the risk of bypassing the capsule without passing through it. The great dimensional stability of the capsule also makes it easier to remove it when the machine is opened after the pressurised water has passed through. 1 8 SEP 2013 - 4 There is no risk that the capsule will be held back or jammed in the piston. According to another advantageous feature, the holes are in the shape of outwardly opening funnels, 5 the narrow parts of which open into the capsule. This funnel shape creates jets of liquid in the volume of the capsule to stir up the substance within it and effectively encourage extraction. According to another advantageous feature the 10 perforated base has a flat central portion inside the circular rib and this central portion has a stiffening dome which rises into the volume of the capsule. This particular shape of the base increases its indeformability and rigidity, with the advantages 15 described above. According to another feature the base is provided with holes arranged in concentric circles. This arrangement of the holes aids manufacture and ensures that pressurised water is regularly distributed 20 within the capsule. According to another feature the circular stiffening rib has a rectangular cross-section with sides and a top, the latter having holes in it. The stiffening rib also has the function of distributing 25 the pressurised water within the capsule as a result of the axial offset of the holes made in the flat parts of the base in the portion surrounded by the rib and in the outer portion in the holes provided in the top of the rib (the top here is the portion of the rib 30 projecting furthest into the volume of the capsule). According to one advantageous feature the rib is bordered with a flat ring forming a junction with a stiffening cone connecting the base to the side wall. This combination of shapes is particularly useful to 18 SEP 2013 - 5 prevent the capsule from being partly deformed inwards at the junction between the base and the side wall. According to another advantageous feature the concentric circles of holes are arranged in the central 5 part of the base, in the circular rib as already indicated and in the flat ring beyond the circular rib. The distribution of holes over the entire lower surface (base) of the capsule allows water to pass through the capsule avoiding too great a pressure difference 10 between the exterior of the capsule subjected to the sudden arrival of highly pressurised hoL water and the interior of the capsule which is at atmospheric pressure at that time. According to another advantageous feature, the 15 capsule has a rim with a top formed by a flat peripheral ring to receive a lid and an underside formed by a ribbed ring comprising a sealing seat to receive the front surface of the machine's piston. This form of sealing joint made under the rim ensures a good 20 seal between the piston and the capsule. Tn particular the circular lips of the ribbed ring have a triangular cross-section thus forming a labyrinth seal with the edge of the machine's piston. According to one advantageous feature, the 25 outermost circular lip is higher than the others and can more readily act together with the edge of the piston and grip the latter. As the capsule is made of a plastics material, the lips have some flexibility and deform to a greater 30 or lesser extent in contact with the edge of the piston, thus ensuring a seal. According to another feature, the underside of the edge comprises an outer stiffening ring. 18 SEP 2013 - 6 The capsule according to the invention is manufactured of injection-moulded plastics material. It is distributed empty to individual customers who fill the capsules with products of their choice and close 5 them with a self-stick lid which is preferably delivered at the same time as the capsules in the form of packed batches. Capsules may also be supplied to roasters who fill them with products, in particular coffees of their choice, to pack them in batches or as 10 single capsules in hermetically sealed packages ensuring that the organoleptic characteristics of the products in the capsules are satisfactorily preserved. Drawings This invention will be described in greater 15 detail below through embodiments of a capsule according to the invention illustrated in the appended drawings in which: - Figure 1 is an isometric view of a capsule seen from below, 20 - Figure 2 is an isometric view of a capsule seen from above, - Figure 3 shows different views of a capsule in its parts 3A-3D, namely: - Figure 3A is a side view of a capsule, 25 - Figure 3B is an axial cross-section of a capsule along the diametric plane AA in Figure 3C, - Figure 3C is a view of a capsule from above, - Figure 3D is a view of a capsule from below, - Figure 4 is a cross-sectional view on a magnified 30 scale of part B of Figure 3B of an embodiment of the rim of a capsule according to the invention, - Figure 5 is a cross-sectional view similar to that in Figure 4 of part B of Figure 3B of another embodiment of the capsule rim, 1 SEP 13 - 7 - Figure 6 is a detailed cross-sectional view of the circular rib at the base of a capsule, corresponding to part C in Figure 3B, - Figure 7 shows the stacking of two capsules, 5 - Figure 8 provides a highly diagrammatical view of the fitting of a capsule in a beverage preparation machine. Description of embodiments of the invention As shown in Figures 1 and 2, the invention 10 relates to a perforated capsule 100, illustrated empty, which is designed to receive a substance used for the preparation of a beverage. The capsule is here shown alone without its lid, which is fitted to the top once the capsule has been filled. 15 Capsule 100 is a body having a shape generated by revolution about an axis. In order to aid presentation this capsule is illustrated with its opening facing upwards in the drawings. However in a coffee machine or device of that type, as the liquid 20 passing through the substance contained within the capsule arrives at the base and then passes through the top, the capsule is generally in a horizontally axial or vertical axial position, but in the latter case upside-down, in such a way that the top with the lid 25 faces downwards. Capsule 100 comprises a perforated base 1 provided with a circular rib 11 projecting into the volume of the capsule and a side wall 3 rising from base 1 and widening according to a profile 30 substantially inscribed within a frustoconical shape necessary for the stacking of empty capsules before they are filled. Base 1 joins side wall 3 through a stiffening frustoconical portion 2, which has a very large angle (of the order to 90*) at the top. Side wall 13 SEP 2013 - 8 3 comprises a cylindrical nesting portion 31 followed by a joining frustoconical portion 32 connected to a main frustoconical portion 33, the opening of which (large base) is provided with a rim 4 intended to 5 receive a lid 5 (Figures 3A, 3B) . The outermost peripheral lip of the ribbed rim is preferably higher than the others so that it holds the piston more tightly and further improves the seal. Main frustoconical portion 33 accounts for most of the 10 height of capsule 100. Details of the structure of capsule 100 in Figures 1 and 2 will be seen more specifically on examination of Figures 3 to 7. Figure 3A is a side view of capsule 100 showing 15 stiffening frustoconical portion 2 starting from the plane of the base with a relatively large angle a (of the order of 450), joining nesting cylinder 31 which itself joins main conical portion 33 of the capsule bearing rim 4 via joining frustoconical portion 32. Lid 20 5 has been illustrated diagrammatically. Figure 3B is a cross-sectional view more clearly showing the shape of capsule 100, and in particular showing the special structure of base 1 with its circular rib 11 coaxial with the axis xx of the 25 overall revolution-generated shape of the capsule. Rib 11 comprises a groove which opens outwards. At the lower extremity of main frustoconical portion 33 (according to the orientation in Figures 3A, 3B) the interior of capsule 100 is provided with radial and 30 longitudinal ribs 34 intended to stiffen the side wall and to assist the capsules in nesting with each other, preventing them from sticking together, and assisting the removal of a capsule from a stack.
- 9 Base 1 comprises a planar surface 12 within the surface bounded by circular rib 11 and at the centre planar surface 12 has a dome 121. Beyond circular rib 11 base 1 has a flat ring 14. 5 Base I is pierced by a set of holes 13 as illustrated in Figures 3B, 3C, 3D. These holes 13 are arranged in circles C1-C4 concentric with circular rib 11 and the axis xx of the capsule. In this embodiment there are four Circular assemblies Cl-C4 of holes 13 10 and the holes are preferably offset in a staggered way from one circular assembly Cl-C4 to the next. In surface 12 within circular rib 11 base 1 has two assemblies Cl-C2 of holes 13 arranged as two circles, six holes in first circle Cl and twelve holes in second 15 circle C2. Circular rib 11 is also pierced by holes 12, (C3); in this embodiment there are twenty holes. Finally, an assembly C4 of holes 13 occupies ring 14 outside circular rib 11. In this case there are twenty six holes. 20 The arrangement of holes 13 in the surface of the base and their different diameters make it possible to obtain a regular flow of liquid throughout the cross-section of the substance in capsule 100 through which the liquid passes, that is to say in the cross 25 section of the capsule. The axial offset (in the xx direction) between holes 13 and surfaces 12, 14 and the holes in rib 11 creates turbulence effects stirring the liquid in contact with the substance and encouraging extraction. 30 Figure 3C illustrates the regular arrangement of holes 13 over the entire surface of base 1, including rib 11 but excluding central portion 12 occupied by dome 121, in such a way as not to create a 181 SEP 3 - 10 preferential passage for liquid along the axis xx of capsule 100. Figure 3D is a view from below of capsule 100 showing more particularly the uniform distribution of 5 holes 13 and their funnel shape. The cross-section of this outwardly opening funnel shape with a curved profile of holes 13 through the wall and the small outlet openings from the holes opening into the interior of the capsule create a very effective water 10 jet 131 as illustrated in the case of hole 13 in the top 113 of rib 11. Holes 13 preferably have the same cross-section and the same shape. The unobstructed diameter of holes 13 is preferably of the order of 0.3 mm. 15 Figure 4 and 5 illustrate two embodiments of rim 4 of capsule 100 according to part B of Figure 3B on a magnified scale. As illustrated in Figure 4, rim 4A has a flat upper surface 41A for the attachment of lid 5. The 20 underside of rim 4A is occupied by a ribbed ring 42A directly surrounding the top of frustoconical portion 33 of the capsule. This ribbed ring 42A comprises a plurality of circular lips 421A of substantially triangular cross-section bordered on the inside and 25 outside (in relation to the xx axis) by an inner ring 43A and an outer ring 44A bounding this ribbed surface. Ribbed ring 42A constitutes the sealing seat against which the edge of the piston holding the capsule in the working position in the equipment bears, forming a 30 labyrinth seal. The top of rim 4A is also provided externally with a stiffening ring 45A. In the case of the embodiment in Figure 5, ribbed ring 42B is only bordered by one stiffening ring 18 SEP 203 - 11 44B, the one located directly alongside the start of frustoconical portion 33 of the capsule being omitted. The other elements are identical to those in the embodiment in Figure 4 and have the same reference 5 numbers in Figure 4 but with the suffix B, and their description is not repeated. Figure 6 is a cross-section of half of base 1 on a magnified scale illustrating the rectangular cross-sectional shape of rigid circular rib 11 with two 10 side walls 111, 112 and a top portion 113; rib 11 forms an open groove in the top of the capsule. Top portion 113 is provided with holes 13 (C3). Figure 6 shows the position of a hole 13 (C3) which passes through top part 113 and that of a hole 13 15 adjacent to second circle C2 in central portion 12 of base 1; first circle of holes Cl is not illustrated in this cross-sectional view because of the offset distribution of the holes. Figure 7 shows the stacking of two capsules 100 20 according to the invention, which are kept separate from each other by ribs 34 within the frustoconical portion 33 of each capsule. Rims 4 of two capsules 100 are sufficiently far apart (distance e) to assist the capsule being seized 25 from above by its rim 4. Figure 8 is a diagrammatical view in cross section illustrating the placing of a capsule 100 according to the invention in a machine for the preparation of beverage with substance present within 30 the capsule. Capsule 100 is for example in an overturned vertical position in relation to the filling position shown in Figures 1, 2, 3A, 3B. The portion of the capsule with its lid 5 is applied against grid 201 of machine 200. A piston 202 of cylindrical shape is - 12 located above capsule 100 and bears through its edge 203 against ribbed ring 42 comprising the sealing seat in such a way as to form a leaktight seal for the enclosure bounded by piston 202 and capsule 100, whose 5 lid 5 has not yet been pierced. Finally the pressurised liquid (pressurised hot water) is delivered to the space enclosed by piston 202. This liquid passes through the various holes 13 in base 1 of capsule 100 to irrigate the substance 10 contained in the capsule. The pressure of the liquid causes lid 5 to burst, being pierced on the mesh of grid 201 against which the capsule is applied. The liquid obtained by contact between the pressurised hot water and the substance is collected in hopper 204 to 15 be delivered to a receptacle 210 such as a cup placed beneath equipment 200. Capsules according to the invention manufactured from injection-moulded material are distributed and used in different ways. They may be 20 distributed in batches to be filled by the user with a substance of his choice to form dose units which can be used in a machine such as a coffee machine. The capsules may also be used by a roaster who fills them and packs them in sealed individual or grouped packages 25 to preserve the organoleptic properties of the substance filling the capsules, such as coffee powder. In the case of an end user who himself fills the capsules with a product such as coffee of his choice, he will fit the capsules with a self-stick lid, 30 supplied separately or together with a batch of capsules. Q8GR .
- 13 KEY 100 Capsule 5 200 Machine/equipment 201 Grid 202 Piston 203 Piston edge 204 Hopper 10 210 Recipient 1 Base 11 Rib 111 Side wall 15 112 Side wall 113 Top part 12 Central part of the base/surface inside the rib 121 Dome 13 Hole 20 131 Jet of liquid leaving hole 13 14 Ring 2 Stiffening cone 25 3 Side wall 31 Nesting cylindrical portion 32 Joining frustoconical portion 33 Main frustoconical portion 30 4, 4A, 4B Rim 41A, B Top surface 42A, B Ribbed ring 421A, B Circular lips 43A Inner ring I EPm - 14 44A, B Outer ring 45A, B Stiffening ring 5 Lid 5 Cl, C2, C3, C4 Circular arrangements of holes 13 xx Axis of revolution of the capsule