Infusion device for preparing beverages using insoluble material

Abstract

Infusion device (10) for preparing beverages using insoluble material, comprising: - a container (12) for receiving the beverage and the insoluble material, wherein the container (12) has an open end (26) and a closed end (28) and defines an axis (X), and - a piston filter assembly (30) that can be inserted into the container (12) through the open end (26) and is movable along the axis (X) towards the closed end (28), - wherein the piston filter assembly (30) comprises a filter element (36) and a sealing section (38), wherein the sealing section (38) surrounds the filter element (36) radially outwards with respect to the axis (X) and seals the piston filter assembly (30) against the container (12), and - comprises a first seal (46) and a second seal (48) that are spaced apart from each other with respect to the axis (X).- the first seal (46) has a first radial extension (ER1) relative to the axis (X) and - the second seal (48) has a second radial extension (ER2) relative to the axis (X), - wherein the first radial extension (ER1) differs from the second radial extension (ER2), - the first seal (46) has a first thickness (T1) and - the second seal (48) has a second thickness (T2), - wherein the first thickness (T1) differs from the second thickness (T2), characterized in that the container (12) has a container extension (ERV) radial to the axis (X), wherein the container extension (ERV) changes along the axis (X).

Description

The present invention relates to an infusion device for preparing beverages using insoluble material. Brewing devices for preparing beverages are also known as coffee presses or filter presses. These devices consist of a container with an open and a closed end, typically cylindrical or prismatic in shape. To prepare a beverage, usually coffee or tea, the desired amount of insoluble material, such as ground coffee or tea leaves, is poured into the container through the open end, and then hot water is poured over it. The grounds or tea leaves are then left to steep for a specific period of time. A piston filter assembly, comprising a piston rod and a filter element attached to the rod, is then placed inside the container. The piston rod is usually mounted in a sliding mechanism within a lid that fits the open end and is used to close the container.The pressure filter is shaped to match the cross-section of the container, ensuring the filter element sits flush against its sides. The piston rod pushes the filter element towards the closed end of the container. This separates the extracted coffee grounds or tea leaves from the coffee or tea and compresses them at the closed end. The filtered coffee or tea is then ready to drink. Once the coffee or tea is completely consumed, the piston filter assembly is removed from the container, and the compressed coffee grounds or tea leaves are discarded. Documents demonstrating the state of the art include DE 34 32 289 C1, WO 02 / 067739 A1, US 11 109 707 B2, EP 3 242 579 B1, US 10 791 866 B2, FR 2 938 172 A1, EP 2 798 985 A1 and WO 96 / 035360 A1. To ensure sufficient separation of the insoluble material from the beverage, the piston filter assembly is equipped with a sealing element that seals it against the inner wall of the container. However, achieving a proper seal between the piston filter assembly and the container has proven challenging. As mentioned above, the piston filter assembly moves downwards towards the closed end. If the contact pressure between the sealing element and the container is too high, this movement can be impeded. If the container is made of glass, there is a risk of damage from the contact pressure. The higher the contact pressure, the greater the wear on the sealing element, which can lead to premature loss or a reduction in its sealing function. If the contact pressure is too low, the separation of the insoluble material from the beverage may be insufficient.Insufficient separation can worsen due to tolerance deviations of the container and relaxation of the sealing element. The object of one embodiment of the present invention is to propose an infusion device for preparing beverages using insoluble material, which overcomes the disadvantages described above. In particular, the present invention proposes an infusion device with a piston filter arrangement that is easily movable within the container and provides long-term and sufficient separation of the insoluble material from the beverage. This problem is solved by a pouring device with the features specified in claim 1. Advantageous embodiments are the subject of the dependent claims. One embodiment of the present invention relates to an infusion device for preparing beverages using insoluble material, comprising: - a container for receiving the beverage and the insoluble material, wherein the container has an open and a closed end and defines an axis, and - a piston filter arrangement that can be inserted into the container through the open end and is movable along the axis towards the closed end, - wherein the piston filter arrangement comprises a filter element and a sealing section, wherein the sealing section surrounds the filter element radially outwards with respect to the axis and seals the piston filter arrangement against the container, and - comprises a first seal and a second seal that are spaced apart from each other with respect to the axis. The first and second seals can be formed by a common sealing element, but the first and second seals can also be separate parts that are connected separately to the piston filter assembly. Insoluble material not separated from the beverage by the second seal can be separated by the first seal. Separation is also improved with reduced contact pressure. Reducing the contact pressure also reduces wear, thus maintaining the improved separation over a longer period. According to the invention, the first seal has a radial extension relative to the axis, and the second seal has a radial extension relative to the axis, wherein the first radial extension differs from the second radial extension. In many cases, the container has a circular cross-section. In this case, the first and second radial extensions can be considered as diameters. Since the first radial extension differs from the second, the first seal can exert a different contact pressure on the container than the second seal. The separation can be improved without affecting the movement of the piston filter assembly within the container. According to the invention, the first seal has a first thickness and the second seal has a second thickness, wherein the first thickness differs from the second thickness. The first and second seal thicknesses allow for adjustment of their flexibility. As mentioned earlier, the brewing device is particularly suitable for preparing coffee and tea. However, the particle size of coffee powder is typically smaller than that of tea leaves. Proper separation, regardless of the type and concentration of the insoluble material used, is ensured by using seals with varying degrees of flexibility. According to the invention, the container has a radial extent with respect to the axis, wherein the radial extent of the container changes along the axis. As mentioned above, the container typically has a circular cross-section. Therefore, the radial extent of the container can also be considered its diameter. Varying container dimensions can be caused by tolerances, especially if the container is made of glass, or may be desirable for design or technical reasons. Because the piston filter assembly incorporates two seals, it can be adjusted to accommodate changing radial container dimensions, thus ensuring proper separation even in cases of fluctuating dimensions. According to another embodiment, viewed from the open end and along the axis, the first seal is arranged in front of the second seal, and the first radial extension is larger than the second radial extension, and the first thickness is less than the second thickness. In this embodiment, it has been found that a high degree of separation can be achieved and a stick-slip effect can be avoided. According to a further embodiment, the container comprises a first container and a second container connected together, which form an intermediate space, wherein the sealing section seals the piston filter arrangement against the first container. The space between the two containers is typically hermetically sealed and filled with air, which acts as insulation. As mentioned earlier, this type of infuser is primarily used for preparing hot beverages such as coffee or tea. Due to the insulating properties of this space, the beverage's temperature is maintained for a longer period compared to single-walled containers. The first container is enclosed by the second, and the beverage is drawn in through the first. Thus, the sealing section works in conjunction with the first container. In a further embodiment, the first container has a radial first container extension with respect to the axis, wherein the radial first container extension changes along the axis. Particularly for design reasons, it may be desirable to provide the first container with a changing diameter. The first and second seals can, in turn, be designed such that proper separation of the pourable material from the beverage is possible despite the changing diameter of the first container. According to another embodiment, the first container and the second container are made of plastic. The use of plastic allows for the production of the first and second containers in larger quantities and at reasonable costs, particularly if they are manufactured by injection molding. To simplify demolding, a diameter that increases slightly from the closed to the open end is advantageous. As already explained, variable diameters can be achieved with the first and second seals to ensure proper separation of the insoluble material. In a further embodiment, the pouring device further comprises a lid that can be inserted into the open end of the container and that has a guide bore running parallel to the axis, wherein the piston filter arrangement comprises a piston rod to which the filter element is attached, and the piston rod passes through the guide bore. The lid can be used to temporarily close the open end, minimizing heat loss and maintaining the beverage's initial temperature for a longer period. It also prevents accidental spillage when pouring the beverage into a tea or coffee cup. Furthermore, the guide hole prevents the piston filter assembly from twisting within the container, ensuring proper separation of the insoluble material from the beverage. Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings. Fig. 1A shows a sectional view of an embodiment of a pouring device according to the invention with a piston filter arrangement in a first position, Fig. 1B is an enlarged section of area A defined in Fig. 1A, Fig. 2A shows a sectional view of an embodiment of a pouring device according to the invention with a piston filter arrangement in a second position, and Fig. 2B is an enlarged section of area B defined in Fig. 2A. Figure 1A shows a sectional view of an embodiment of a pouring device 10 according to the invention. The pouring device 10, as shown in Figure 1A, comprises a container 12 formed by a first container 14 and a second container 16. Both the first container 14 and the second container 16 are cylindrical. The first container 14 is inserted into the second container 16 and arranged concentrically with respect to an axis X. The first container 14 and the second container 16 are made of plastic and are joined to each other by a connecting section 18. The first container 14 and the second container 16 can be joined by a material bond such as welding or gluing, or by other suitable means. In the joined state, the first container 14 and the second container 16 enclose an air-filled space 20.The gap 20 can be sealed with a container seal 21 to prevent air exchange. The first container 14 forms a spout 22. A handle 24 is attached to the second container 16. The container 12, in this case the first container 14, forms an open end 26 and a closed end 28. A piston filter assembly 30 can be inserted into the first container 14 through the open end 26. The piston filter assembly 30 comprises a disc-shaped retaining frame 32 attached to a piston rod 14. A filter element 36 is attached to the retaining frame 32. Furthermore, an angled sealing section 38 is formed around the filter element 36. A lid 40 is inserted into the open end 26 of the first container 14 and provided with a guide bore 42 extending concentrically to the axis X. The piston rod 34 penetrates the guide bore 43 and is thereby positioned concentrically to the axis X. As can be seen particularly in Fig. 1B, which shows an enlarged view of the area defined in Fig. 1A, the sealing section 38 is formed by a sealing element 44 that encloses the filter element 36 and has a first seal 46 and a second seal 48. Viewed from the open end 26 along the axis X, the first seal 46 is arranged in front of the second seal 48. The first seal 46 has a first radial extension ER1 with respect to the axis X, and the second seal 48 has a second radial extension ER2 with respect to the axis X. As mentioned, the first container 14 is cylindrical. Since the first seal 46 and the second seal 48 can seal the filter assembly against the first container 14, the first radial extension ER1 and the second radial extension ER2 can also be considered the diameters of the first seal 46 and the second seal 48, respectively. As shown in Fig. 1A, the container 12 has a radial container extension ERV with respect to the axis X, which in this case is formed by the first container 14 and can also be referred to as the radial first container extension ERC. Both the radial container extension ERV and the radial first container extension ERC refer to the internal extension of the container 12 and the first container 14, respectively. The radial container extension ERV and the radial first container extension ERC change along the X axis. Starting from the open end 26, the radial first container extension ERC1 decreases in a region between the spout 22 and the connecting section 16. Then, the radial first container extension ERC decreases only slightly towards the closed end 28. The first radial extension ER1 of the first seal 46 is larger than the second radial extension ER2 of the second seal 48 (see Fig. 1B). Furthermore, the first seal 46 has a first thickness T1 and the second seal 48 has a second thickness T2. The first thickness T1 is smaller than the second thickness T2. The brewing device 10 is operated as follows: To prepare coffee or tea, the desired amount of insoluble material, such as coffee grounds or tea leaves, is placed through the open end 26 into the first container 14, and then hot water is poured over it. The grounds or tea leaves are then allowed to steep for a specific period of time. Subsequently, the lid 40, together with the piston filter assembly 30, is inserted into the open end 26 of the first container 14, as best illustrated in Fig. 1A. The retaining frame 32 abuts or almost abuts the lid 40, and the piston rod 34 protrudes to its maximum or almost maximum extent from the top of the lid 40. As can be seen particularly clearly in Fig. 1B, only the first seal 46 rests against the first container 14. The piston filter assembly 30 is now moved towards the closed end 28 of the container 12 by pressing down the piston rod 34. As a result, the extracted coffee powder or tea leaves are separated from the coffee or tea and compressed in the area of ​​the closed end 28 (see Fig. 2A and Fig. 2B). As mentioned, the radial first container extension ERC decreases along axis A towards the closed end 28. Consequently, not only the first seal 46 but also the second seal 48 are in contact with the first container 14. Due to the respective larger first radial extension ER1 and smaller first thickness T1 compared to the second radial extension ER2 and second thickness T2, the first seal 46 is bent more than the second seal 48 (Fig. 2B). Therefore, the contact area between the first seal 46 and the first container 14 is larger than the contact area between the second seal 48 and the first container 14. The further the sealing section 38 moves towards the closed end 28, the higher the concentration of the insoluble material. The second seal 48 can also remain in contact with the first container 14 if the pressure exerted on the second seal 48 by the insoluble material is quite high. The filtered coffee or tea can now be drunk. To do this, the brewing device 10 can be grasped by the handle 24 and tilted so that the beverage can flow out of the first container 14 via the spout 22. After the coffee or tea has been completely drunk, the piston filter assembly 39 is removed from the container 12 and the compressed coffee grounds or tea leaves are emptied from the container 12. Reference symbol list 10 Pouring device 12 Container 14 First container 16 Second container 18 Connecting section 20 Space 21 Container seal 22 Spout 24 Handle 26 Open end 28 Closed end 30 Piston filter assembly 32 Retaining frame 34 Piston rod 36 Filter element 38 Sealing section 40 Lid 42 Guide bore 44 Sealing element 46 First seal 48 Second seal A Axis ERC Radial first container extension ERV Radial container extension ER1 First radial extension ER2 Second radial extension T1 First thickness T2 Second thickness

Claims

Infusion device (10) for preparing beverages using insoluble material, comprising: - a container (12) for receiving the beverage and the insoluble material, wherein the container (12) has an open end (26) and a closed end (28) and defines an axis (X), and - a piston filter assembly (30) that can be inserted into the container (12) through the open end (26) and is movable along the axis (X) towards the closed end (28), - wherein the piston filter assembly (30) comprises a filter element (36) and a sealing section (38), wherein the sealing section (38) surrounds the filter element (36) radially outwards with respect to the axis (X) and seals the piston filter assembly (30) against the container (12), and - comprises a first seal (46) and a second seal (48) that are spaced apart from each other with respect to the axis (X).- the first seal (46) has a first radial extension (ER1) relative to the axis (X) and - the second seal (48) has a second radial extension (ER2) relative to the axis (X), - wherein the first radial extension (ER1) differs from the second radial extension (ER2), - the first seal (46) has a first thickness (T1) and - the second seal (48) has a second thickness (T2), - wherein the first thickness (T1) differs from the second thickness (T2), characterized in that the container (12) has a container extension (ERV) radial to the axis (X), wherein the container extension (ERV) changes along the axis (X). Pouring device (10) according to claim 1, characterized in that, viewed from the open end (26) and along the axis (X), the first seal (46) is arranged in front of the second seal (48) and the first radial extension (ER1) is larger than the second radial extension (ER2) and the first thickness (T1) is less than the second thickness (T2). Pouring device (10) according to one of the preceding claims, characterized in that the container (12) has a first (14) and second container (16) connected to each other, which form an intermediate space (20), wherein the sealing section (38) seals the piston filter arrangement (30) against the first container (14). Pouring device (10) according to claim 3, characterized in that the first container (14) has a container extension (ERC) radial with respect to the axis (X), wherein the radial first container extension (ERC) changes along the axis (X). Pouring device (10) according to one of claims 3 or 4, characterized in that the first container (14) or the second container (16) are made of plastic. Pouring device (10) according to one of the preceding claims, characterized in that the pouring device (10) further comprises: - a lid (40) which can be inserted into the open end (26) of the container (12) and has a guide bore (42) extending parallel to the axis (X), wherein - the piston filter arrangement (30) comprises a piston rod (34) to which the filter element (36) is attached, - wherein the piston rod (34) passes through the guide bore (42).

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