Capsule for receiving coffee powder

Abstract

The invention relates to a capsule for receiving coffee powder and producing a coffee beverage using water in a device which receives the capsule. The capsule has a container with an interior which can be accessed via an opening and a cover for reversibly opening and closing the opening by means of a user, and a snap-action disc is mounted on the container and / or on the cover, said snap-action disc being designed such that below a specified pressure in the capsule, the disc is in an unsnapped state, and above the specified pressure in the capsule, the disc is in a snapped state. The snap-action disc is designed and mounted such that the disc seals off the interior of the capsule from the outside in the unsnapped state and releases an opening to the outside in the snapped state.

Description

Capsule for holding coffee powder

[0001] The present invention relates to a capsule for receiving coffee powder and for preparing a coffee beverage with the aid of water in a device receiving the capsule, wherein the capsule has a container with an interior accessible via an opening and a lid for reversibly opening and closing the opening by a user.

[0002] Capsule coffee and capsule coffee machines have become widespread. In addition to the first provider of capsule coffee machines and disposable capsules, many providers are now active in the market, offering either their own disposable systems or disposable capsules that are compatible with the capsule coffee machines of other providers. Disposable capsules can be made of metal or plastic, or both. Due to the small amount of coffee per capsule (usually around 5.5 g), the amount of metal and plastic waste per kilogram of coffee powder is relatively high, as the disposable capsules must be disposed of after one use.

[0003] Disposable capsules usually consist of a container filled with coffee powder and a lid to close the container once it has been filled with coffee powder. They usually have a circumferential flange that can be clamped between two receptacles in the associated capsule coffee machine to form at least one enclosed space on one side of the flange. The flange is usually located on the side of the container that is closed off by the lid. During the brewing process, water is introduced into this enclosed space, usually at a higher pressure than ambient pressure, to flow through the inlet openings into the disposable capsule and through the coffee powder, mixing with it and dissolving substances from the coffee powder. The maximum achievable water pressure in typical capsule coffee machines is usually between 3 and 25 bar.

[0004] The prepared coffee beverage usually exits the disposable capsule on the side opposite the clamped flange. For this purpose, disposable capsules usually have a lid designed as a thin membrane made of aluminum or plastic. This membrane tears during the brewing process when a certain pressure is reached in the capsule. The tears serve as outlets for the coffee beverage. For this purpose, the membrane can usually be positioned against a relief disc, which, thanks to its shape, supports the tearing at a relatively precise pressure.

[0005] As an alternative to disposable capsules, various manufacturers have been offering refillable capsules for several years. These refillable capsules are compatible with disposable capsules or with capsule coffee machines designed for disposable capsules. The advantage of these refillable capsules is the reduced amount of waste and the ability to choose your own coffee, which can significantly reduce the cost per serving or allow you to consciously use a specific type of coffee.

[0006] The basic principle of many refillable capsules is that they consist of at least two parts: the container for holding the coffee grounds and a lid that serves as a cover for sealing the container after it has been filled with coffee grounds. The lid can be connected to the container to seal the coffee grounds. The container or lid is often not closed, but rather has inlet openings for allowing water to enter the capsule during the brewing process and outlet openings for the finished coffee beverage to escape from the capsule.

[0007] In their basic form, refillable capsules usually correspond to the disposable capsule, for which they are intended as a refillable alternative, or to the corresponding receptacle geometry in the corresponding capsule coffee machine, in order to achieve the largest possible volume for the coffee powder, close to that of the disposable capsule. In contrast to the disposable capsule, a refillable capsule usually has recesses at the points where parts of the capsule coffee machine penetrate the disposable capsule when the disposable capsule is inserted into the capsule coffee machine and the machine is closed. These can be structures, for example, that pierce the disposable capsule to form an inlet for the water.If the refillable capsule is rotationally symmetrical and can therefore be inserted into the capsule coffee machine in any orientation, then such recesses must also be rotationally symmetrical, for example, as an annular groove, to prevent contact between the structures and the capsule in any possible insertion position of the capsule into the capsule coffee machine. An example of a refillable capsule is described in document EP 2 604 151 B1.

[0008] The inlet openings on refillable capsules are usually located on one side of the flange, and the outlet openings for the coffee beverage are located on the other side of the flange. In either case, the side of the capsule where the water is introduced must be sealed against the refillable capsule holder in the capsule coffee machine so that the water flows through the capsule and not past it. To do this, the flange of a refillable capsule is usually clamped between two parts of the capsule coffee machine to create an enclosed space on one side of the flange into which water is introduced and can then flow through the inlet openings into the refillable capsules.

[0009] EP 2 483 177 B1 proposes a coffee capsule suitable for preparing a coffee beverage in a beverage dispenser. It comprises a thin-walled, frustoconical housing part, a base part provided with inflow openings for an extraction fluid, and a lid part having at least one outlet opening. The outlet opening of the lid part is covered by a membrane having a plurality of perforations and is permanently connected to the lid part.

[0010] EP 3 088 330 A1 describes a capsule for beverages consisting of a housing closed by pierceable barriers at the top and bottom, and intended for the preparation of hot liquid foodstuffs, in particular beverages such as cappuccino and coffee. The capsule is characterized in that, inside a housing, at the level of the upper part of the housing, between an upper barrier and the surface of a separator sealed along its periphery to the inner surface of the housing, there is a bushing provided at the base with openings for the outflow of the liquid for mixing the substances in the direction from the separator to the upper barrier, and the outflow from each hole in the separator is controlled by a pressure regulating valve.

[0011] CH 708 662 A1 discloses a capsule having a preferably rotationally symmetrical capsule body with a side wall and a base formed in particular integrally therewith, as well as a lid covering the capsule body to form a closed chamber containing a substance for preparing a liquid food. The capsule has an outlet opening for dispensing the liquid food in the region of the base. The outlet opening is closed with a valve, wherein the valve has a valve opening and is designed such that the valve opening is open under a working pressure prevailing in the capsule and closed in a pressure-free rest state.

[0012] WO 2015 / 173375 A1 describes a beverage capsule comprising: a container defining a chamber for storing beverage material, the container being designed so that a fluid entering the chamber can build up pressure, and a valve means switchable from a first setting in which the escape of pressurised fluid from the chamber is prevented to a second setting in which the escape of pressurised fluid from the chamber is permitted, the valve means subsequently being switchable from the second setting to the first setting. Technical task

[0013] The object of the invention is to provide a simple and efficient capsule for receiving coffee powder and for producing a high-quality coffee beverage with the aid of water in a device receiving the capsule.

[0014] This object is achieved by the subject matter of claim 1. Preferred developments of the invention are described in the subclaims.

[0015] Characteristics of a high-quality coffee beverage from a capsule include good taste, a good consistency, and, in the case of an espresso, a sufficient amount of foam, the so-called crema. These characteristics depend on the type of coffee, the amount of coffee powder filled into the capsule, the degree of grinding, the resulting different particle sizes and their proportions in the coffee powder, as well as the compression of the coffee powder in the capsule before brewing.

[0016] How the water flows through the capsule during the brewing process is also crucial, especially for an espresso. When the brewing process begins in a capsule coffee machine, heated water is pumped into the capsule under increased pressure. The capsule is designed to open only when a certain pressure is reached, forming an outlet for the coffee. Until the capsule opens, the water or the resulting coffee does not escape from the capsule, but rather collects in the capsule, moistening the coffee powder or mixing with it, causing it to swell.

[0017] Ideally, the entire coffee powder is moistened and fills the interior of the capsule completely and evenly before it is opened and the actual extraction of the coffee beverage begins. This allows the now moistened and swollen coffee powder to be more evenly distributed by the water during extraction. It is also less likely that channels will form in the coffee powder through which the water entering the capsule flows too quickly to the outlet openings without coming into sufficient contact with all of the coffee powder. The previously described effect of water and coffee powder mixing before extraction begins is also called pre-infusion. When the term pre-infusion is used below, it refers to the effect described above.Pre-infusion results in improved taste, better consistency and more crema in the prepared coffee beverage, especially in espresso-type beverages.

[0018] For optimal coffee from a capsule, the following should be observed: The capsule's outlet opening should remain closed during the brewing process until a certain pressure is reached within the capsule. After opening, the outlet opening should remain open with significantly less pressure than necessary for opening, or even without pressure, so that the coffee can pass through the outlet opening at the lowest possible flow rate. Furthermore, the volume in the capsule available for ground coffee should be as large as possible, and the space required for the closure mechanism of the outlet opening should be as small as possible.

[0019] The present invention addresses all of this in a simple and efficient manner. Terms

[0020] In this case, the terms listed below are understood as explained below.

[0021] "Brewing process" means the preparation of a coffee beverage with a capsule coffee machine; this term includes pre-infusion and extraction.

[0022] "Extraction" means the extraction of aroma and flavor substances from the coffee powder by passing heated water under increased pressure through the coffee powder and, after being enriched with the dissolved aroma and flavor substances, flowing out of the coffee powder as a coffee beverage.

[0023] "Coffee powder" means roasted and ground coffee beans and products containing roasted and ground coffee beans.

[0024] "Coffee beverage" means any beverage produced by passing cold or heated water, at no pressure or at a pressure higher than ambient pressure, through coffee grounds and interacting with them.

[0025] "Capsule" refers to any type of container designed to hold ground coffee and prepare a coffee beverage by introducing cold or heated water, which interacts with the ground coffee in the capsule and then exits the capsule as a coffee beverage, into a capsule-based coffee machine designed to hold the capsule. The term "capsule" here includes both disposable capsules, which must be disposed of after one use, and refillable capsules, which can be refilled with fresh ground coffee several times. If only one of the two versions is explicitly meant, the terms "disposable capsule" or "refillable capsule" are used instead of capsule. It also includes all parts necessary for preparing a coffee beverage, whether permanently attached to the capsule or separate, such as, in particular, seals for sealing the capsule against the capsule-based coffee machine or for sealing the lid against the capsule.The terms "capsule", "disposable capsule" and "refillable capsule" can refer to both the unsealed capsule with an opening for filling the coffee powder, as well as the capsule already filled with coffee powder and sealed.

[0026] "Capsule coffee machine" means any device for preparing a coffee beverage designed to accept capsules, where preparation occurs by passing water through coffee powder contained in a capsule. This includes cold and heated water, and passing water without or with increased pressure.

[0027] "Opening pressure" refers to the pressure in the capsule during the brewing process at which the valve orifice opens. With a snap-action disc or bimetallic snap-action disc, the snap-action force of the snap-action disc or bimetallic snap-action disc corresponds to the opening pressure.

[0028] The term "profile-like" in this case means "expanding linearly with a constant cross-section".

[0029] "Relief disc" refers to a surface in a capsule coffee machine against which the surface of a disposable capsule rests, where the outlet openings in the disposable capsule are created or introduced during the preparation of a coffee beverage. This usually occurs when water introduced into the capsule under pressure presses the surface of the capsule against the relief disc. When a certain pressure is reached, the surface of the capsule tears at the relief disc. This occurs because the relief disc has raised and depressed areas, e.g., in the shape of pyramids with flattened tips, and the surface tears when pressed into the depressions.

[0030] "Outlet opening" or "outlet openings" means one or more openings in a capsule through which coffee beverage can exit the capsule.

[0031] "Container" means the part of a capsule that, due to its shape, can hold the coffee powder.

[0032] "Lid" means the part of a capsule that closes the capsule by connecting to the container.

[0033] "Inlet opening" or "inlet openings" means an opening or openings in the container or lid through which water can enter a capsule for the preparation of a coffee beverage.

[0034] "Elastically deformable" means the deformability of a component by applying a force, whereby the deformed component opposes the applied force with a force, like a spring, and that the component returns to its original shape after the applied force is removed, like a spring.

[0035] "Disc with a protrusion" refers to a separate component or part of a container or lid that has a protrusion that, due to its shape, can fit so tightly against a valve opening that it is closed. In this case, this means that the pressure inside the capsule can increase during the brewing process until the opening pressure is reached, at which point a significantly larger cross-section of the valve opening is exposed. The disc can also have multiple protrusions to close multiple valve openings.

[0036] "Filter disc" means a separate part or part of the container or lid that separates the coffee powder in the capsule from the snap-in disc when the capsule is closed.

[0037] "Valve opening" means an opening in a separate part or a part of the container or lid, which can be closed by a closure element, in particular a formation on a disc with a formation or a valve pin, so tightly that the pressure inside the capsule can increase during the brewing process until the opening pressure is reached and from then on the valve opening opens and a considerably larger cross-section of the valve opening is exposed.

[0038] "Valve pin" means a separate part or a separate part that is attached to the screen disc, or an integral part of the screen disc, which has at least one location a profile-like cross-section that corresponds to the shape of the valve opening, and which projects into it and thereby closes it, and which, with its complete profile-like cross-section, can be moved with little play but freely into and out of the valve opening.

[0039] "Snap-on disc" means a circular or otherwise shaped disc having a curvature extending over the entire disc or only a part of it, whereby the curvature snaps over when a force is applied to the curvature once the snap-over force is reached and then remains snapped over when a force smaller than the snap-over force is applied until the snap-back force is exceeded and the curvature snaps back to its original shape.

[0040] "Bimetallic snap-action disc" refers to a disc that snaps open without the application of any external force when the snap-open temperature is reached and remains closed as long as it does not fall below the snap-back temperature. If the snap-open action is triggered by applying a force to the dome below the snap-open temperature but above the snap-back temperature, the disc will remain closed on its own, even without any further force being applied to the dome, as long as the temperature does not fall below the snap-back temperature.

[0041] "Return force" refers to the force on the curvature of a snap-on dome that must be undercut for the dome to snap back against the return force. The return force is significantly lower than the return force.

[0042] "Snap-back temperature" means the temperature below which a snapped bimetal snap-action disc snaps back on its own, i.e. without the application of force.

[0043] "Snap-over force" refers to the force that must be applied to the curvature of a snap-action disc to cause it to snap over. For a bimetallic snap-action disc, the snap-over force decreases with increasing temperature.

[0044] "Snap point" refers to the point to which the dome of a snap-action disc must be depressed by applying the snap-action force to the dome, so that from this point onward, the disc can be snapped over by applying a significantly smaller force, and to remain snapped over when the significantly smaller force is continued. In the case of a bimetallic snap-action disc, the term also refers to the point to which it slowly deforms when heated before quickly snapping over on its own when the snap-action temperature is reached.

[0045] "Snap-over temperature" means the temperature at which a bimetallic snap-action disc snaps over on its own, i.e. without the application of any force. Technical solution

[0046] A key aspect of the invention is that the capsule is equipped with a snap-action disc. Snap-action discs are known from the prior art. Snap-action discs are used, for example, in electrical tactile switches to generate tactile feedback. Bimetallic snap-action discs are used, for example, in snap-action thermostats to switch an electrical circuit when a certain temperature is reached.

[0047] The valve opening can be located in the snap-action disc and closed by another component, or the valve opening can be located in a component other than the snap-action disc and closed by the snap-action disc. In both cases, the valve opens by the snap-action disc snapping over, which is triggered when the water introduced into the capsule reaches a certain pressure against the snap-action disc.

[0048] The solution according to the invention can be implemented both with one valve opening and with several valve openings, even if the description of the individual solutions and embodiments only refers to an embodiment with a single valve opening or only to an embodiment with several valve openings.

[0049] In addition to using one snap dome, it is also possible to use several snap domes, even if the description of the individual solutions and embodiments only refers to a version with one snap dome.

[0050] By appropriately designing the snap disc, the opening pressure can be determined at which the valve opening should open or at which the snap disc snaps over.

[0051] With a snap disc, the valve opening opens suddenly when the opening pressure is reached, which corresponds to the snap-back force of the snap disc, and the valve opening remains open as long as the pressure in the capsule on the snap disc is so high that the snap-back force is not exceeded.

[0052] With a bimetallic snap disc, the valve also opens abruptly when the opening pressure corresponding to the snap disc's snap-over force is reached. Even if no pressure in the capsule acts on the snap disc, it remains snapped over after snapping until the bimetallic snap disc has fallen below the snap-back temperature, provided this temperature was exceeded during snapping. If this is not the case during snapping, the bimetallic snap disc behaves like a non-bimetallic snap disc and snaps back as soon as the snap-back force is exceeded.

[0053] A preferred design is one in which the snap-action is triggered when a certain pressure is reached in the capsule, and the bimetal snap-action disc remains snapped after snapping so that the coffee beverage can flow through the valve without pressure against the snap-action disc. For this to happen, the snap-back temperature must be safely exceeded during the brewing process. The snap-action temperature, however, should never be reached so that the bimetal snap-action disc is only snapped by the pressure in the capsule and not by reaching a certain temperature. As the temperature rises, the snap-action force of a bimetal snap-action disc decreases until the snap-action temperature is reached, when the disc snaps automatically. The bimetal snap-action disc is therefore preferably designed so that it snaps when the water flowing into the capsule has reached a temperature typical during the brewing process, and the pressure in the capsule has reached the desired opening pressure.The snapping force or snapping temperature can be adjusted to the desired values ​​for the snapping force at a specific temperature by adjusting the size of the disc, the material, the thickness, and the depth of the curvature. By incorporating radially or concentrically embossed ribs, rigidity can be increased, allowing for a flatter curvature or a lower material thickness with the same snapping force, thus reducing the installation space.

[0054] The solution according to the invention is preferably implemented in refillable capsules with a rotationally symmetrically shaped container and lid. Designs are described for this variant, but they can also be implemented in the same way with differently shaped containers and lids, for example, rectangular or polygonal ones.

[0055] The solution according to the invention is preferably applicable to refillable capsules with a diameter in the region of the connection between the container and lid of 25 mm to 75 mm, preferably 32 mm to 60 mm, and a total height of the capsule, measured vertically to the connection plane of the container and lid, of 12 mm to 60 mm, preferably 20 mm to 42 mm. Metal can preferably be used as the material for the container and lid, but plastic can also be used, or one material for the lid and the other for the container. The solution according to the invention is independent of the type of connection between the container and lid.

[0056] All of the following exemplary embodiments of the inventive solution show a lid designed as a round turned part and accommodating the other components in a concentric opening in its center. There are further possible designs, for example, in which the inventive solution is housed in the container instead of the lid, or in which the lid can be designed not as a turned part but as a formed sheet metal part, and in this case, the snap-action disc or the screen disc can optionally also be an integral part of the lid.

[0057] The individual components are described below in the order in which they are installed in the refillable capsule.

[0058] “Valve pin” version

[0059] In one possible design, the lid or container of a refillable capsule contains a mesh disc, which can be a separate part or an integral part of the lid or container. It is preferably arranged on the side of a refillable capsule, which rests against the relief disc of the capsule coffee machine during the brewing process. It can be a separate component permanently attached to the lid or container, or it can be removed and reinserted by the user. If it is removable, it should fit so tightly against the component in which it is installed, i.e. the lid or container, that no coffee grounds can penetrate through the gap between it and the component that holds it.

[0060] It is designed to absorb the pressure of the coffee grounds expanding when moistened with water without significantly deforming, as the position of a valve pin connected to it, which closes the valve opening, changes relative to the snap-action disc, thus also changing the opening pressure. This includes the pressure exerted by the moistened coffee grounds on the filter disc during the brewing process, because it opposes the flow resistance of the pressurized water, resulting in a force equal to the maximum pressure of the coffee machine multiplied by the projected contact surface of the coffee grounds on the filter disc.

[0061] The stiffer the filter disc, the shorter the travel of the snap disc until it reaches the snap-over point, as it has to compensate for less theoretically possible deformation of the filter disc. To achieve this, it can be given inherent rigidity through suitable shaping, for example, by having the shape of a dome that curves into the interior of the capsule toward the coffee grounds and rests at the edge on the component that holds it, such as the lid or container. The inherent rigidity can also be influenced by the choice of material. Metal or plastic are possible, preferably a higher-strength stainless steel, so that it can be made as thin as possible.

[0062] Instead of increasing the rigidity of the mesh disc, the valve pin can also protrude further into the valve opening than necessary for opening at the desired opening pressure and protrude on the other side of the snap disc to a structure of the capsule coffee machine, e.g., the relief disc, in order to support itself against it. The valve pin must then have a significantly smaller cross-section in the further protruding part in order to achieve a sufficiently large cross-section of the open valve opening. The transition between the part of the valve pin with the profile-like cross-section and the further protruding part with the significantly smaller cross-section can be designed with sharp edges or as a rounded transition to the significantly smaller cross-section.The dimension of the significantly smaller cross-section relative to the cross-section of the valve opening depends on the required open cross-section of the valve opening, which should be similar to the cross-section of the openings in the capsule coffee machine for the outflow of the prepared coffee beverage.

[0063] The sieve disc, as a separate component, is preferably round, but it can also have a different shape. The size of the individual openings in the sieve disc depends on the particle size of the coffee powder they are intended to retain. It can be between 0.05 mm and 0.7 mm, preferably between 0.2 mm and 0.4 mm.

[0064] On the side of the filter disc facing away from the interior of the capsule there is a snap-action disc which encloses the coffee powder and the filter disc in the capsule when the container and lid of the capsule are connected. It is preferably a separate part but can also be an integral part of the lid or container. There is a valve opening in the snap-action disc which is preferably round but can also have a different shape. The valve opening is closed by the valve pin which can be a separate part, attached to the filter disc as a separate part or can be an integral part of the filter disc. The profile-like cross-section of the valve pin must protrude far enough into the valve opening that, taking all tolerances into account, it always reaches at least as far as the snap-action disc's snap-action point.This ensures that the valve opening is only opened, and thus the pressure inside the capsule drops, when the snap-action disc has passed the snap-over point and only a significantly lower pressure is required to keep it in that state, or in the case of a bimetallic snap-action disc, it reaches the fully snapped-over position without pressure and remains there if it has exceeded the snap-back temperature during snap-over.

[0065] The valve pin is preferably round, but can also be shaped differently. It must have a profile-like cross-section in the area over which the valve opening moves, i.e., a cylindrical cross-section for the preferred round valve opening.

[0066] In order to achieve the previously described necessary tightness of the closed valve opening, the width of the gap between the profile-like cross-section of the valve pin and the valve opening in the snap-action disc should preferably be between 0.005 mm and 0.15 mm, preferably between 0.02 mm and 0.05 mm, depending on the size of the profile-like cross-section and thus on the total length of the gap.

[0067] During the brewing process, pressurized water is pumped into the capsule. This water flows through the coffee grounds, passes through the filter disc, and finally, as the pressure inside the capsule increases, pushes the snap-on disc outward and heats it. When the opening pressure is reached, the snap-on disc snaps over, so that the section of the valve pin with the profile-like cross-section is no longer in the valve opening, creating a larger gap.

[0068] Design “Shaping”

[0069] Another possible design involves a mesh disc in the lid or container of a refillable capsule, as described in the "valve pin" solution. The difference is that there is no valve pin connected to the mesh disc. A snap-action disc is located on the side of the mesh disc facing away from the interior of the capsule, as described in the "valve pin" solution.

[0070] Between the mesh disc and the snap-action disc is an elastically deformable disc with a recess that can close the valve opening in the snap-action disc when, after installation in the lid or container of a capsule, it is pressed against it due to its elastic deformation. The recess can preferably be in the shape of a dome, a cone, or another form.

[0071] For this to happen, the protrusion must match the shape of the valve opening so that a sufficiently small gap is created between the protrusion and the valve opening. To achieve the previously described required tightness of the closed valve opening, the width of the gap should be between 0 mm and 0.15 mm, preferably between 0.01 mm and 0.05 mm, depending on the size of the cross-section of the valve opening. To improve the seal between the protrusion and the valve opening, an elastomer material can also be partially or completely applied to the side of the snap disc on which the protrusion rests. This allows for larger tolerances in the valve opening and protrusion. The thickness of the elastomer can be between 0.1 mm and 1 mm, preferably 0.2 mm to 0.5 mm. The disc with a protrusion can preferably be a separate part or an integral part of the lid or container.The disc with a recess should be designed so that coffee can flow from the side with the filter disc to the side with the snap-on disc during the brewing process. To achieve this, the disc with a recess can have openings or cutouts on the edge.

[0072] During the brewing process, water under pressure is fed into the capsule. This water flows through the coffee grounds, can pass through the sieve disc and the disc with a formation and presses against the snap disc, heating it. When the opening pressure is reached, the snap disc snaps over. The formation of the disc with a formation is pressed against the valve opening and closes it until the snap disc passes the snap point. The formation of the disc with a formation then strikes a stop and the valve opening in the snap disc opens when the snap disc is pushed further past the snap point, or in the case of a bimetallic snap disc, it deforms further into the snapped end position on its own.

[0073] A surface of the capsule coffee machine can serve as a stop for the capping. Another possible design is a stop in the capsule itself. For this to happen, the capping must be prevented from continuing to rest on the valve opening and closing it when the opening pressure is reached by a connection to the filter disc, once the snap disc has passed the snap-action point during the snap-action process.

[0074] Version “snap-on disc without hole”

[0075] In another possible design, there is a mesh disc in the lid or container of a refillable capsule, as described in the "valve pin" solution. The difference is that there is no valve pin connected to the mesh disc. On the side of the mesh disc facing away from the interior of the capsule, there is a disc with an outlet opening that encloses the coffee powder and the mesh disc in the capsule when the container and lid of the capsule are connected. It is preferably a separate part but can also be an integral part of the lid or container. The outlet opening is preferably round, but can also have a different shape. A design with multiple outlet openings is also possible.

[0076] A bimetallic snap-action disc is located between the screen disc and the disc with the outlet opening. The bimetallic snap-action disc is pressed against a circumferential bead in the disc with the outlet opening, within which the outlet opening(s) are located. To achieve this, the curvature of the bimetallic snap-action disc must match that of the circumferential bead, so that a sufficiently small gap is created when the bimetallic snap-action disc rests on the circumferential bead or is pressed onto it. The curvature of the bimetallic snap-action disc is preferably rotationally symmetrical, and the shape of the circumferential bead is correspondingly circular.

[0077] To achieve the previously described required tightness in the closed state, the width of the gap should be between 0 mm and 0.15 mm, preferably between 0.005 mm and 0.05 mm, depending on the diameter of the circumferential bead. To improve the seal between the circumferential bead and the snap-action disc, an elastomer can be partially or completely applied to the side of the snap-action disc that rests against the closure element or the contact surface in the interior of the capsule. This allows for larger tolerances between the circumferential bead and the snap-action disc. The thickness of the elastomer can be between 0.1 mm and 1 mm, preferably between 0.2 mm and 0.5 mm.

[0078] The outlet opening should be designed so that when the bimetallic snap-action disc rests on the edge of the outlet opening after snapping, the coffee mixture can still flow between it and the edge of the outlet opening. To achieve this, the edge of the outlet opening can be corrugated up and down, or the outlet opening can have a shape that differs from the section of the bimetallic snap-action disc that rests on it.

[0079] The bimetallic snap-action disc should be pressed against the circumferential bead in the disc with the outlet opening with sufficient pressure to remain closed until the opening pressure is reached. This can be achieved by ensuring that the space between the screen disc and the disc with the outlet opening is slightly lower than the height of the bimetallic snap-action disc, thus pre-tensioning the disc against the circumferential bead and the screen disc. The bimetallic snap-action disc can preferably be a separate part or an integral part of the lid or container.

[0080] If the bimetal snap-action disc does not have cutouts on the edge, then the sieve disc, which presses the bimetal snap-action disc against the disc with the outlet opening, must have formations in the direction of the bimetal snap-action disc, on which the bimetal snap-action disc can rest, so that coffee beverage can flow through the gap between the formations.

[0081] During the brewing process, water under pressure is fed into the capsule, which flows through the coffee powder, can pass through the filter disc, and as the pressure in the capsule increases, presses against the bimetal snap-on disc and heats it up.

[0082] When the opening pressure is reached, the bimetal snap-action disc snaps over, no longer rests on the surrounding bead and clears the way to the outlet opening.

[0083] The invention is explained in more detail below with reference to drawings which merely represent exemplary embodiments. In the drawings, Fig.1a

[0084] a preferred embodiment of the valve pin solution, where the dashed line shows the position of the valve disc and the disc with a formation when the valve opening is open, Fig.1b

[0085] a partially sectioned perspective view of, Fig.2

[0086] a preferred embodiment of the solution “shaping” as a section of a side view, wherein the dashed line shows the position of the valve disc and the disc with a shaping when the valve opening is open, Fig.3a

[0087] a further preferred embodiment of the solution “shaping” as a section of a side view, wherein the dashed line shows the position of the valve disc and the disc with a shaping when the valve opening is open, Fig.3b

[0088] a view in the direction of the rotation axis of the pin in the disc with a formation and Fig.4

[0089] a preferred embodiment of the “snap disc without hole” solution as a section of a side view of a capsule, wherein the dashed line shows the position of the bimetallic snap disc when the valve opening is open.

[0090] For a better understanding, only the cut surface of the sieve disc is shown in,,and, but not the edges of the wall sections and the openings in the sieve disc.

[0091] shows a preferred embodiment of the "valve pin" solution as a sectioned side view. For better understanding, only the cut surface of the screen disc is shown. The dashed line shows the position of the snap disc when the valve opening is open. shows a partially sectioned perspective view of the.

[0092] A sieve disc 3 and a snap-action disc 4 are arranged in the lid 2 of a capsule, which is manufactured as a ring-shaped turned part made of metal. On its outer edge, the lid 2 has a flange 14 which accommodates a seal 10. On its inner edge, the lid 2 has a circumferential step 13 on which the snap-action disc 4 rests. At the outer edge of the step 13 is a conical circumferential wall, which has an inwardly projecting circumferential bead 12 at its upper end, against which the wall sections of the sieve disc 3 are supported. On the outer side there is a circumferential groove 11 into which the container 1, with its inlet openings 16 provided therein, can snap into place when it is to be connected to the lid 2. For this purpose, the container has gill-like cutouts at two opposite locations towards the interior of the container.These can snap into the groove when pressed over the conical circumferential wall, causing the open part of the container to deform into an oval. When locked in place, the edge of the container can be pressed against the seal 10 to seal the connection between container and lid. Alternatively, the conical circumferential wall can be recessed at its upper end at two opposite points, to the depth of the circumferential groove 11 and slightly wider than the gill-like cutouts, so that the container can be placed onto the lid without deformation, and by rotating it relative to the lid, the gill-like cutouts in the groove are positioned next to the recessed points, similar to a bayonet fit.

[0093] The snap-action disc 4 is designed with a valve opening 6 in the center. The snap-action disc 4 can be produced by stamping, and the valve opening 6 in the center with the required tolerance by fine blanking. The screen disc 3 has the shape of a rotationally symmetrical dome and is made of stainless spring steel. On the outer edge of the dome-shaped area, it has a conical, upwardly opening, circumferential wall with sixteen radial incisions around it, two of which are located alternately only in the circumferential wall and two of which extend a few millimeters into the dome. The wall sections between the incisions, which extend deep into the dome, are slightly curved upwards compared to the other wall sections in the dome and act like a spring, the upper edge of which can deflect both parallel to the dome's axis of rotation and vertically to it.The wall sections between the notches located only in the peripheral wall, on the other hand, act like a spring, whose upper edge can only deflect vertically relative to the rotational axis of the cap. The valve pin 5 is designed as an integral part of the screen disc 3, which can be achieved by deep drawing during the production of the screen disc 3. The outer contour and the openings in the screen disc 3 can be created by punching, and the final shape of the cap and the peripheral wall sections can be achieved by pressing.

[0094] When assembling the cover 2, the snap-action disc 4 is placed on the circumferential step 13 in the cover 2. The mesh disc 3 is pressed onto the snap-action disc 4 by the inwardly projecting circumferential bead 12 on the cover 2, whereby the valve pin 5 on the mesh disc 3 must find its way into the valve opening 6 in the snap-action disc 4. First, the wall sections of the mesh disc 3 that are not bent upwards engage under the circumferential bead 12. By applying pressure to the four upwardly bent wall sections of the mesh disc 3, these are pressed downwards, then also engage under the circumferential bead 12 and press the outer edge of the dome-shaped area of ​​the mesh disc 3 against the snap-action disc 4 and this against the circumferential step 13 in the cover 2.

[0095] The surface on the circumferential bulge 12, behind which the wall sections of the sieve disc 3 engage, is angled. The angle is dimensioned such that the upper edges of the wall sections of the sieve disc 3 are pushed outwards as far as possible by their spring action until they lie at the end of the inclined surface on the circumferential bulge 12. The sieve disc 3 and the snap-action disc 4 are removed by pressing against the snap-action disc 4 in the direction of the capsule interior. The upper edges of the wall sections of the sieve disc 3 slide over the inclined surface on the circumferential bulge 12 and are pressed inwards until they have passed the narrowest point of the circumferential bulge 12 and the sieve disc 3 can be pressed out of the lid 2 with little force. The sieve disc 3 and snap-action disc 4 can thus be removed and reassembled for cleaning without tools.

[0096] shows a preferred embodiment of the "shape" solution as a section of a side view. For better understanding, only the cross-sectional surface of the screen disc is shown. The dashed line shows the position of the snap disc and the disc with a shape when the valve opening is open.

[0097] The structure is essentially identical to that in the exemplary embodiment in. One difference, however, is that a disk with a formation 7 is arranged between the snap-action disk 4 and the sieve disk 3. The disk with a formation 7 is designed as an elastically deformable disk made of stainless spring steel, specifically with several holes to allow coffee beverage to pass from the sieve disk 3 to the valve opening 6, a formation in the form of a truncated cone in the area of ​​the contact surface to the valve opening 6 of the snap-action disk 4 and a calotte as a closure, which can strike a surface of the capsule coffee machine when the disk with a formation 7 is elastically deformed outwards. The necessary elastic deformability is achieved by the relatively thin wall thickness of 0.2 - 0.3 mm. The sieve disk 3 is therefore essentially designed as described in the exemplary embodiment. The difference, however, is that it does not have a valve pin.

[0098] shows a preferred embodiment of the "shaping" solution as a section of a side view, showing a view in the direction of the rotation axis of the valve pin in the disc with a shape. For better understanding, only the sectional surface of the screen disc is shown. The dashed line shows the position of the snap disc and the disc with a shape when the valve opening is open.

[0099] The structure is essentially identical to that in the exemplary embodiment in. One difference, however, is that the sieve disc 3 has a hole in the middle that is in the shape of two semicircles, the ends of which are each connected by straight lines. A further difference is that the formation of the disc with a formation 7 does not have a calotte as a finish, but rather a flat surface. A pin 17 is attached to this by spot welding. The pin 17 has a cylindrical cross-section in the middle part and a cross-section at its head that corresponds to the hole in the sieve disc 3, but is reduced by slightly more than the manufacturing tolerances of both parts in order to always be able to pass through freely. The pin 17 can be inserted through the hole in the sieve disc 3 with its head in one alignment. After a rotation of a few degrees, preferably 30° - 90°, the head can no longer be passed through the hole.The cylindrical part of the pin 17 can then still be freely moved up and down in the hole when a disc with a protrusion 7 and the sieve disc 3 are inserted into the lid 2 in this position relative to each other. The sieve disc 3 thus serves as a stop for the disc with a protrusion 7 and limits the deformation or the outward path of the disc with a protrusion 7 when the snap-action disc 4 is pressed outwards by the pressure in the capsule during the brewing process.

[0100] shows a preferred embodiment of the "snap disc without a hole" solution as a section of a side view of a capsule. For better understanding, only the cross-sectional surface of the screen disc is shown. The dashed line shows the position of the bimetallic snap disc when the valve opening is open.

[0101] The structure is essentially identical to that in the exemplary embodiment, with the following differences: Instead of a snap-action disc, a round disc with an outlet opening 9 rests on the circumferential step 13 on the cover 2. It has a concentric, circumferential bead that projects into the interior of the capsule, on which the sieve disc 3 rests. The bead also serves as a lateral guide for the bimetallic snap-action disc 4, for which the distance to the bead must be large enough, even with the largest manufacturing tolerances, that the edge of the bimetallic snap-action disc 4 can move freely up and down when snapping over.

[0102] The disc with outlet opening 9 has another, slightly smaller, concentric, circumferential ridge extending into the interior of the capsule, against which the bimetallic snap-action disc 4 is pressed. Within this ridge is an outlet opening 6 with an edge that undulates up and down in a wave-like manner, allowing the coffee beverage to flow between the bimetallic snap-action disc 4 and the disc with outlet opening 9 to the outlet opening 6 when the bimetallic snap-action disc 4 is snapped over and no longer rests on the slightly smaller ridge, but rather on the edge of the outlet opening 6.

[0103] The filter disc 3 is essentially designed as described in the exemplary embodiment. One difference is that it does not have a valve pin, but rather at least three protrusions facing the bimetallic snap-action disc 4, upon which it can rest when it is snapped over, allowing the coffee beverage to flow through the gap between the protrusions. Another difference is that it has a protrusion in the center facing the bimetallic snap-action disc 4, which, when not snapped over, presses it against the smaller, concentric, circumferential bulge in the disc with outlet opening 9.

[0104] The opening behavior of this design is such that the bimetallic snap-action disc 4 snaps over as soon as the opening pressure and thus the snap-action force of the bimetallic snap-action disc 4 is reached inside the capsule during the brewing process. The bimetallic snap-action disc 4 releases the valve opening 6 as soon as it has snapped over beyond the snap-action point and no longer rests on the smaller, concentric, circumferential bead. It snaps back into place as soon as the snap-action temperature is reached again during cooling.

[0105] 1 container

[0106] 2 lids

[0107] 3 sieve disc

[0108] 4 Snap dome

[0109] 5 Valve pin

[0110] 6 Valve opening

[0111] 7 Disc with a shape

[0112] 8 Formation

[0113] 9 Disc with outlet opening

[0114] 10 Seal on the lid

[0115] 11 Groove on the lid

[0116] 12 bulge on the lid

[0117] 13 steps on the lid

[0118] 14 Flange on the cover

[0119] 15 openings in the sieve disc

[0120] 16 inlet openings

[0121] 17 pen

Claims

Capsule for holding coffee powder and for preparing a coffee beverage with the aid of water in a device holding the capsule, which has a container (1) with an interior accessible via an opening and a lid (2) for reversibly opening and closing the opening by a user, wherein a snap-action disc (4) is arranged on the container (1) and / or on the lid (2), which is designed such that it is in a non-snap-over state below a predetermined pressure in the capsule and in a snap-over state above the predetermined pressure in the capsule, and which is in a non-snap-over state again when the pressure drops below a predetermined value, and the snap-action disc (4) is designed and arranged such that, in the non-snap-over state, it seals the interior of the capsule to the outside and, in the snap-over state, opens an opening to the outside, which allowsthat coffee beverage can escape from the interior of the capsule to the outside. Capsule according to claim 1, wherein the snap-action disc (4) has at least one valve opening (6) which is closed by a closure element in the non-snap-action state of the snap-action disc (4) and which is open in the snap-action state of the snap-action disc (4). Capsule according to claim 2, wherein the closure element has a region whose cross section corresponds to the shape of the valve opening (6) in the snap-action disc and which, in the non-snapped state, sits sealingly in the valve opening (6), wherein the closure element is designed and arranged such that when the snap-action disc (4) snaps from the non-snapped state to the snapped state, it does not move with the latter but remains in its position, so that the valve opening (6) is opened. Capsule according to claim 2, wherein the closure element is pressed against the valve opening (6) by a resilient element and the closure element moves with the snap-action disc (4) from the non-snapped state to the snapped state when the latter snaps over, but is stopped by a stop after the snap-action disc (4) has passed the snap-over point and the closure element then no longer closes the valve opening (6). Capsule according to claim 3, wherein the closure element has a first region which corresponds in shape and size to the valve opening (6), and a second region adjacent to the first region which tapers in the direction in which the snap-action disc (4) snaps over. Capsule according to claim 1, wherein the snap-action disc (4) is designed and arranged in such a way that, in the non-snapped state, it presses with its circumferential edge against a contact surface in the interior of the capsule to seal the interior of the capsule and, in the snapped state, is at a distance from the contact surface, wherein the contact surface forms a closed circumferential line within which there is at least one opening in the capsule through which, in the snapped state of the snap-action disc (4), coffee beverage can escape from the interior of the capsule to the outside. Capsule according to one of the preceding claims, wherein the snap-action disc (4) is designed as a bimetallic snap-action disc. Capsule according to one of the preceding claims, wherein a sieve disc (3) is arranged upstream of the snap-action disc (4) towards the interior, said sieve disc being provided with openings (15) designed in such a way that they retain coffee powder but allow coffee beverage to pass through. Capsule according to claim 4, 6 or 7, wherein an elastomer is partially or completely applied to the side of the snap disc (4) which bears against the closure element or against the contact surface in the interior of the capsule. Capsule according to one of the preceding claims, wherein the snap-action disc (4) has radially or concentrically embossed ribs

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