Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/42—Details
  • A47L15/4209—Insulation arrangements, e.g. for sound damping or heat insulation
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/42—Details
  • A47L15/4251—Details of the casing
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/42—Details
  • A47L15/48—Drying arrangements
  • A47L15/488—Connections of the tub with the ambient air, e.g. air intake or venting arrangements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
  • B29C44/34—Auxiliary operations
  • B29C44/35—Component parts; Details or accessories
  • B29C44/355—Characteristics of the foam, e.g. having particular surface properties or structure
  • B29C44/357—Auxetic foams, i.e. material with negative Poisson ratio; anti rubber; dilatational; re-entrant

Definitions

• the invention relates to a sealing device for a household item, in particular for a household appliance.
• the invention further relates to a method for manufacturing a sealing device and to a household item, in particular a household appliance, comprising at least one sealing device.
• Dish washers for example need to have thermally and acoustically insulating walls during the cleaning period in order to avoid heat losses and to save energy, while thermally conductive walls during the drying period would be beneficial in order to reduce the required drying time.
• a further task of the invention consists in providing a method for manufacturing such a sealing device. Still further, it is an object of the current invention to provide a household item comprising such a sealing device.
• a sealing device for a household item a method for manufacturing a sealing device for a household item, and a household item according to the independent claims.
• Advantageous developments of the invention are specified in the respective dependent claims, wherein advantageous developments of the sealing device are to be regarded as advantageous developments of the method and the household item and vice versa.
• a first aspect of the invention relates to a sealing device for a household item, in particular for a household appliance, comprising at least one sealing body with several voids and comprising at least one switching means, which is switchable at least between a first state and a second state, wherein the voids of the sealing body at least in the first state are capable of allowing a fluid to flow through and in the second state have a smaller cross-sectional area that is capable of allowing a fluid to flow through than in the first state.
• the sealing device can thus be switched between a first "open” state, in which a fluid can flow through the voids, and a second "partially open” or “closed” state, in which compared to the first state less fluid per time or at least substantially no fluid can pass through the voids.
• the first and the second state refer to the same or at least comparable flowing conditions of the fluid.
• the sealing device according to the invention can thus be switched between at least the first and the second state, thereby varying the possible flow-rate of said fluid.
• the sealing device can thus for example be used in connection with a dish washer. During the washing period, the sealing device is switched in the second state to ensure good thermal and acoustic insulation.
• the sealing device may be switched in the first state, thereby allowing the throughflow of hot steam and thus reduced drying times.
• a porous gas burner that allows the flame to go through the sealing device in the first state and that can be closed by switching the sealing device into the second state to avoid gas leaks or damages by the flame.
• the fluid may generally be a liquid, a suspension, a dispersion and/or a gas.
• the sealing body at least partly consists of an auxetic material and the switching means is configured to change the dimension of the sealing body for switching between the first and the second state.
• auxetic materials generally have a negative Poisson's ratio.
• the switching means may be configured to apply a mechanical displacement of the sealing body, for example via pistons, rack-pinions or the like, to stretch or relax the sealing body in order to switch between the first and second state.
• the switching means may be configured to induce thermal stress in order to change the dimension of the sealing body.
• the auxetic material is a polyether foam, in particular with a mean pore size of between 0.4 mm and 0.8 mm, e.g. 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm, and/or with a volumetric density of between 20 kg/m 3 and 40 kg/m 3 , e.g.
• the polyether foam may for example be "RP30048 Richfoam Polyether", provided by the firm Carpenter.
• the sealing body comprises several voids, wherein at least in part of the voids at least one closure body is arranged, wherein the closure bodies in the first state allowe the fluid to flow through the voids and in the second state at least largely close the voids.
• the sealing device may be designed comparable to an assembly of ball valves.
• the sealing body forms a continuous solid phase, while the voids form a continuous gas phase.
• the voids form a discontinuous gas phase due to the closure bodies.
• only one closure body is arranged in each void.
• one or more closure bodies are arranged only in some of the voids.
• more than one closure bodies are arranged in some or all voids.
• the closure bodies at least partly consist of a magnetic material, in particular steel, and that the switching means is configured to move the closure bodies by means of a magnetic field in the first state into a first position at least partly uncovering the voids and/or in the second state into a second position at least largely closing the voids.
• the closure bodies may thus be moved jointly in a contact-free manner by means of a magnetic field to switch the sealing device between the first and the second state. It may be envisaged that the magnetic field is only used to move the closure bodies in one of the states and that the closure bodies move in the other position in the absence of a magnetic field to shift the sealing device in the other state, for example due to gravity.
• the magnetic field may be used to move the closure bodies between the first and the second position.
• a suitable material for the closure bodies is for example AISI 430 (ferritic), AISI 630 (precipitation hardening) or 420 (martensitic) steel. Steel is preferred in many applications due to its corrosion resistance. However, other magnetic materials may generally be used in addition to or instead of steel.
• the closure bodies are configured as switching means and by pressure and/or temperature dependent change in volume are switchable between the first state and the second state.
• the closure bodies due to their inherent properties function as switching means so that the sealing device can be shifted between the at least two states by pressure and/or temperature changes in the surrounding area.
• This can for example be realized by using different materials with sufficiently differing thermal expansion coefficients for the closure bodies and the sealing body to vary the cross-sectional area of the voids.
• the closure bodies can for example comprise or consist of AISI 316 L (austenitic) or AISI 630 steel, both having thermal expension coefficients of at least 18*10 "6 K "1 at 20 °C.
• polymeric materials such as ethylene acrylic acid copolymers (EEA), polybutylene (PB) and the like, can have thermal expension coefficients between 288*10 "6 K “1 and 450*10 "6 K “1 (EEA) or 424*10 "6 K “1 - 432*10 "B K “1 (PB) at 20 °C and can be equally used.
• EAA ethylene acrylic acid copolymers
• PB polybutylene
• the closure bodies are spherical and/or comprise an elastic, in particular rubbery-elastic coating.
• This provides particularly reliable sealing properties of the sealing device in the first state. If the coating has elastic properties, it allows growing and shrinking of the respective closure body and is thus particularly useful in combination with the use of materials with high thermal expension coefficients as core material of the closure body.
• coating materials elastomeres, in particular perfluoroelastomers, or silicones may for example be used.
• at least part of voids of the sealing body are bounded by at least one barrier element in order to prevent a dropping out of the at least one closure body from the void. This ensures a reliable operation due to the dropout safe arrangement of the respective closure body.
• the barrier element may for example be configured as a protrusion.
• the sealing body at least partly is configured as open-pore foam and/or that the voids of the sealing body at least partly are arranged in a grid-type manner. This allows a simple adaptation of the sealing properties to different applications.
• a second aspect of the invention relates to a method for manufacturing a sealing device according to the first aspect of the invention, in which at least one sealing body is provided with several voids and with at least one switching means, which is switchable between a first state and a second state, wherein the voids of the sealing body at least in the first state allow for fluid to flow through and in the second state comprise a smaller cross-sectional area allowing for fluid to flow through than in the first state.
• the thus manufactured sealing device can be switched between a first "open” state, in which a fluid can flow through the voids, and a second "partially open” or “closed” state, in which less fluid per time or at least substantially no fluid can pass through the voids compared to the first state, for example under the same or at least under comparable flowing conditions of the fluid.
• the sealing device according to the invention can thus be switched between at least the first and the second state, thereby varying the possible flow-rate of said fluid.
• the sealing device can thus for example be used in connection with a dish washer. During the washing period, the sealing device is switched in the second or "closed” state to ensure good thermal and acoustic insulation.
• the sealing device can be switched in the first or "open" state, thereby allowing the throughflow of hot steam and thus shorter drying times.
• Other applications are also conceivable, for example, a porous gas burner that allows the flame to go through the sealing device in the first state and that can be closed by switching the sealing device in the second state to avoid gas leaks or damages by the flame.
• the fluid may generally be a liquid, a suspension, a dispersion and/or a gas.
• At least the sealing body is manufactured by an additive manufacturing method, by an injection molding method, by an injection foaming method, by a sintering method, or by a combination thereof.
• an additive manufacturing method allows the sealing device to be manufactured depending on the selected materials and its future application.
• Additive manufacturing processes allow the manufacturing of complex geometries with undercuts so that the sealing device may be adapted to different household items or appliances.
• injection molding and/or injection foaming may be used to manufacture the sealing device particularly fast and at low cost.
• the sealing body is at least partly manufactured from at least one material, which is selected from the group of plastics, metals, metal alloys, and ceramic materials. This allows for optimal adaptation to different specifications and requirements.
• the sealing body is manufactured with voids comprising passage openings and at least one closure body is arranged in at least one part of the voids in order to uncover in the first state the passage openings at least partly and in the second state to close the passage openings at least largely.
• the closure bodies may equally be manufactured from at least one material, which is selected from the group of plastics, metals, metal alloys, and ceramic materials.
• the closure bodies maybe placed into some or all voids of the sealing body during the manufacturing so that the sealing bodies can easily be secured by at least one barrier element manufactured later within their respective voids.
• the closure body's raw materials may be injected together with the sealing body's raw material or placed within the sealing body's material after the injection/expansion of the sealing body's raw material.
• a third aspect of the invention relates to a household item, in particular a household appliance, comprising at least one sealing device, which is configured according to the first aspect of the invention and/or is obtainable and/or obtained by means of a method according to the second aspect of the invention.
• the houshold item is configured as water conducting household appliance, in particular dish washer or laundry care device for washing and/or drying laundry, or as cooking device for food items.
• Fig. 1 a perspective view of a sealing device according to a first embodiment
• Fig. 2 a sectional top view of the sealing device
• Fig. 3 a perspective view of the sealing device according to a second embodiment
• Fig. 4 an enlarged external view of a void which is limited by a barrier element
• Fig. 5 an enlarged internal view of the void and the barrier element
• Fig. 6 an enlarged internal view of the void and an alternatively formed barrier element
• Fig. 7 a perspective view of the sealing device according to a further embodiment
• Fig. 8 a perspective top view of the sealing device
• Fig. 9 a schematic view of an auxetic sealing body in a second state
• Fig. 10 a schematic view of the auxetic sealing body in a first state
• Fig. 1 a perspective view of the sealing device according to a further embodiment, wherein the sealing device is shifted into the first state;
• Fig. 12 a perspective view of the sealing device which is shifted into the second state.
• Fig. 1 shows a perspective view of a sealing device 1 according to a first embodiment and will be discussed together with Fig. 2, showing a sectional top view of the sealing device 1.
• the sealing device 1 is configured to be used as an "on/off multivalve" in a dish washer and comprises a sealing body 2 which is generally rectangular, one site open, made of plastic, and comprises several voids 3 in an outer wall.
• the voids 3 are arranged grid-like and are in fluid communication with a hollow interior of the sealing body 2 and thus with the opening 4.
• One spherical closure body 5 is placed in each void 3.
• Each void 3 or pore therefore comprises a central section with a substantially spherical geometry, wherein a diameter of the spherical central section is bigger than the diameter of the closure bodies 5 so that the closure bodies 5 can move freely within the central section.
• the closure bodies 5 consist of magnetic steel and can be moved within the voids 3 by switching means 6 in order to switch the sealing device 1 between a first or "open” state and a second or “closed” state.
• the voids 3 of the sealing body 2 in the first state are capable of allowing a fluid to flow through.
• the voids 3 are blocked by the closure bodies 5 so that the cross-sectional area that is capable of allowing a fluid to flow through is lower than in the first state.
• the inlet or outlet portion of the voids 3 is completely blocked by the closure bodies 5 so that no or at least substantially no fluid can pass through under the given conditions.
• the switching means 6 is configured to move the closure bodies 5 by generating a magnetic field near the surface of the sealing body 2.
• the closure bodies 5 are moved from the bottom of the voids 3 to the duct portion of the voids 3 to close the inlet or cross-sectional area, thereby shifting the sealing device 1 from the first state into the second state. If the magnetic field is deactivated, the closure bodies 5 drop down into the central section and allow the passage of a fluid through the sealing device 1.
• the operating principle of the switching means 6 may be inversed. Further, the switching means 6 may generally be located at different locations as need be and may for example be integrated into the sealing device 1 . The sealing device 1 can thus be switched between an open porosity state and a closed porosity state.
• Fig. 3 shows a perspective view of the sealing device 1 according to a second embodiment.
• the sealing device 1 according to the second embodiment has a higher throughput in the first state because the geometry of the voids 3 has been prolonged while the diameter of the central sections is the same as in the first embodiment.
• the voids 3 have been equipped with two solid barrier elements 7 (protrusions).
• a further difference to the first embodiment consists in that the left row of the grid-like arranged voids 3 is devoid of any closure bodies 5 and thus always in the first or "open" state. This optional embodiment ensures a certain minimum flow rate of the fluid regardless of the shifting state of the sealing device 1 .
• Fig. 4 shows an enlarged external view of a void 3 which is limited by said barrier element 7, while Fig. 5 shows an enlarged internal view of the void 3 and the barrier element 7.
• the barrier element 7 has a spherical inner shape in order to accommodate the respective spherical closure body 5 and to close the fluid passage through the void 3.
• Fig. 6 shows an enlarged internal view of the void 3 and an alternatively formed barrier element 7.
• the closure body 5 has to be attracted perpendicularly to the surface so that a stronger magnetic field is needed compared to the previous examples.
• Fig. 7 shows a perspective view of the sealing device 1 according to a further embodiment
• Fig. 8 shows a perspective top view of this sealing device 1 .
• This embodiment allows to change the sealing device 1 from "opened porosity" to "closed porosity”.
• the voids 3 are adjacent to each other and fluidly interconnected via small passages. If the magnetic field is disabled, the spherical sealing bodies 5 (not shown) gather at the bottom or lower surface of the voids 3 and allow fluid to flow through the sealing device 1. In this first state, the sealing device 1 has an "open porosity". If the magnetic field is switched on via the switching means 6, the closure bodies 5 are forced to close the passages between the voids 3, thereby preventing that fluid can pass the sealing device 1.
• the sealing device 1 has a "closed porosity".
• a suitable material for the closure bodies 5 is for example AISI 430 (ferritic), AISI 630 (precipitation hardening), AISI 316 L (austenitic), AISI 630, or 420 (martensitic) steel.
• closure bodies 5 are made of materials with a high thermal expansion coefficient. With this configuration, lower temperatures lead to smaller diameter closure bodies 5 so that fluid can flow through the then "porous" sealing device 1. At higher temperatures, the closure bodies 5 will grow and reduce the flow rate or completely close the voids 3 so that the sealing device 1 has a kind of "closed porosity".
• the closure bodies 5 can generally be magnetic particles. Further the closure bodies 5 may be provided with a coating in order to guarantee an optimum tightness in the second state. If the coating has elastic and in particular rubbery-elastic properties, the coating can easily adapt to changes in size due to temperature changes.
• Fig. 9 shows a schematic view of an auxetic sealing body 2 in a second state
• Fig. 10 shows a schematic view of the auxetic sealing body 2 in a first state
• the main property of auxetic materials is a negative Poisson coefficient. This means that the sealing body 2 becomes thicker perpendicular to the applied force I when stretched. Together with the sealing body 2 also the voids 3 and their cross-sectional area grow, thereby allowing the fluid to pass the sealing device 1 with a higher flow-rate.
• a comparison of the height of the sealing device 1 in the first state Xa and in the second state Xb is depicted in Fig. 10.
• the porosity and thus the maximum flow-rate of the fluid can be modified by stretching or releasing the sealing device 1.
• the force I can for example be applied by shifting means 6 comprising mechanical displacement items such as pistons, rack-pinions or the like.
• shifting means 6 comprising mechanical displacement items such as pistons, rack-pinions or the like.
• changes in temperature can be used to shift the sealing device 1 between the first and second state so that the sealing device 1 can easily be integrated in household appliances, for example in dishwasher tubs, oven cavities or the like.
• a suitable auxetic material is for example "RP30048 Richfoam Polyether", provided by the firm Carpenter. If an auxetic material is used to manufacture the sealing body 2, closure bodies 5 can additionally be used to modify the porosity.
• the closure bodies 5 can again be made of stainless steel (AISI 316 L, AISI 430...) to avoid corrosion problems.
• Fig. 11 shows a perspective view of the sealing device 1 according to a further embodiment, wherein the sealing device 1 is shifted into the first state to allow fluid to flow through the sealing device 1.
• Fig. 12 shows a perspective view of the sealing device 1 which is shifted into the second state so that fluid cannot pass the sealing device 1.
• the sealing device 1 comprises a sealing body 2 made of a very porous material (more than 15 cells per 1 cm), such as foams or porous ceramics.
• the sealing body 2 comprises underneath the voids 3 ferrite particles as closure bodies (not shown) that can be displaced via a magnetic field to shift the sealing device
• the magnetic field can be generated by corresponding shifting means (not shown).
• the sealing device 1 can be integrated for example into a dishwasher tub.
• the dishwasher may thus be provided to have insulating walls during washing periods to avoid heat losses and conductive walls during drying periods to reduce the drying time.
• a gas burner may be equipped with the sealing device 1 to allow flames to pass the sealing device 1 in the first state and to seal the burner in the second state.
• any household item or household appliance which is in any way associated with smoke, vapor, liquids, air, gas, or other fluids can be equipped with the sealing device 1 in order to variably allow the fluid to flow through the sealing device 1 or to block the passage of the fluid.
• the sealing device 1 thus can for example be designed as a cover or tap for household items or appliances for the preparation of food.
• the sealing device 1 may for example be formed as a pan cover or lid.
• the sealing device 1 may generally be manufactured by additive manufacturing processes in order to allow the introduction of closure bodies 5 into the porous structure of the sealing body 2. This technology is ideal for sealing devices 1 with complex geometries. Alternatively, injection moulding could be used to produce certain embodiments of the sealing device 1 . The selection of appropriate raw materials such as powders, magnetic closure bodies 5, main material (steel, ceramic, plastic and the like), and binder if needed depends on the desired shape and properties of the sealing device 1.
• the closure bodies 5 should generally withstand high temperatures in order to allow sintering or molding of the main material without problems.
• any optional binder compositions should generally be selected to have low fusion temperatures in order to allow easy debinding.
• injection foaming processes can also be used to manufacture at least the sealing body 2.
• a wide range of polymer foams and metallic foams can be used for this purpose.

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• Gasket Seals (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=60957358

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (15)

• 2016
  • 2016-12-20 ES ES201631623A patent/ES2673213B1/es not_active Expired - Fee Related
• 2017
  • 2017-12-15 EP EP17829026.8A patent/EP3558617A2/en not_active Withdrawn
  • 2017-12-15 WO PCT/IB2017/057997 patent/WO2018116100A2/en unknown
  • 2017-12-15 CN CN201780078275.9A patent/CN110087850A/zh active Pending

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