Cap for water filter vessel
A convex water filter cover with a specific geometric ratio and optional ribs enhances strength and reduces material use, addressing the weakness of plastic caps by balancing strength and consumption.
Patent Information
- Application Number
- PCT/RU2024/050331
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-01-10
- Filing Date
- 2024-12-25
- Publication Date
- 2025-07-17
AI Technical Summary
Existing water filter caps made of food grade plastics are weak in strength and deformation resistance compared to stainless steel, necessitating thick walls to compensate, leading to excessive material consumption, especially for large diameters.
A water filter cover design with a convex upper part having a specific geometric ratio (Si/S2 from 0.5 to 0.37) and controlled curvature (94 to 118% R) that balances strength and material consumption, optionally with stiffening ribs, ensuring optimal material usage without compromising safety.
The new design achieves a high strength-to-material ratio, reducing material consumption while maintaining structural integrity under pressure, even with reduced wall thickness.
Smart Images

Figure RU2024050331_17072025_PF_FP_ABST
Abstract
Description
[0001] WATER FILTER BOWL COVER
[0002] AREA OF TECHNOLOGY
[0003] The invention relates to the field of water filtration equipment, and more specifically to water filter flask covers.
[0004] LEVEL OF TECHNOLOGY
[0005] The ability of tank shells to withstand the pressure of a fluid medium is influenced by many factors, the main ones being the wall material, its thickness and shape.
[0006] A filter cover is known from the Russian Federation patent for utility model No. 208898, which has a threaded part, an upper part of the form and fittings for connection to pipelines. The upper part of the cover is made in a dome shape. However, the published description of the patent does not contain information that allows determining the parameters characterizing the shape of the cover and affecting its strength along with the choice of material and wall thickness, in particular the radius of curvature, the ratio between the height of the top and the diameter. The values of these parameters cannot be established from the figures in the patent, since they are conditional, are not drawn to scale and do not have other geometric references that allow quantitative calculations.
[0007] Food grade plastics are currently used to manufacture filter caps, due to the ease of their molding. However, in terms of strength and resistance to deformation, food grade plastics are significantly inferior to stainless steels, which is why plastic caps must have a sufficiently thick wall. Moreover, the wall thickness is usually chosen with a large margin, taking into account many factors: - instability of the plastic composition,
[0008] - casting defects (e.g. gas bubbles, uneven filling of the mold),
[0009] - internal stresses due to uneven cooling in the mold,
[0010] - mechanical stresses when connecting to pipelines,
[0011] - hydraulic shocks,
[0012] - pressure surges,
[0013] - increased brittleness with decreasing temperature, etc.,
[0014] - increased fluidity when using hot water.
[0015] However, increasing the wall thickness leads to a significant increase in the material consumption of the product, which becomes especially noticeable when manufacturing large diameter lids.
[0016] In this regard, achieving the required strength only by increasing the wall thickness leads to unsatisfactory results in terms of their material consumption, and it is necessary to propose some alternative approach that improves the ratio between strength and material consumption.
[0017] DISCLOSURE OF INVENTION
[0018] The objective of the invention is to create a cover for a water filter that has a better ratio between strength and material consumption compared to the above-mentioned analogue.
[0019] The technical result achieved by using the proposed cover is the achievement of a high ratio between strength and material consumption.
[0020] It was found that flat lids, all other things being equal, are inferior to convex ones. Not all convex lids are equally strong, for example, spherical lids are stronger than conical lids. The strength is also affected by the geometric parameters of convex bodies, for example, all other things being equal, the strength of spherical lids depends on the ratio of their height to diameter (and the associated ratio of the radius of curvature to diameter).
[0021] The best results in strength and resistance to deformation were achieved under otherwise equal conditions, when the ratio of areas Si / S2 (see Fig. 7) was in the range from 0.5 to 0.37. This ratio characterizes the degree of convexity of the top of the lid. With significant deviations from the optimal values (when the top is strongly convex, voluminous, or, conversely, flattened), the strength of the lid decreases, and therefore, to compensate, it is necessary to increase the wall thickness, which in turn increases the material consumption. At the same time, it is necessary to take into account that not every wall shape that ensures the specified ratio Si / S2 is optimal. It is necessary to take into account that the section must be sufficiently smooth without sharp breaks and other unusual local features that concentrate stress.In this connection, in addition to the ratio Si / S2, it is necessary that along the entire length from the mating zone of the upper and lower parts of the lid to the axis, the curvature of the wall r does not deviate too much from R equal to the distance from the axis to the mating zone of the upper and lower parts of the lid. As has been established, any noticeable stress concentration is not observed in lids of any shape with the specified ratio Si / S2, when the radius of curvature of the top of the lid is in the range from 94 to 118% R.
[0022] Thus, the said problem is solved due to the fact that the proposed cover for the water filter flask comprises: a lower part provided with means for connecting to the water filter flask, an upper part having a convex wall, the outer and inner surfaces of which are at least partially formed by bodies of revolution, characterized in that the ratio SI / S2 in it is from 0.5 to 0.37, where:
[0023] S1 - the area of the part of square K located above the center line passing in the section of the mentioned wall at an equal distance from the outer and inner surfaces of the wall,
[0024] S2 is the area of the part of square K located below the center line located in the section of said wall at an equal distance from the outer and inner surfaces of the wall, wherein square K lies in the secant plane, and its lower corner is located in the mating zone of the upper and lower parts of the cover at a distance R from its axis, and the upper corner is on its axis, and the shape of the section of said wall is such that between the upper and lower lines formed at the intersection of the secant plane with the outer and inner surfaces of said wall, a line with a radius of curvature varying in the range from 94 to 118% R can be inscribed.
[0025] The above-described cover, in one of its particular forms of execution, can have a ratio Si / S2 = 0.4 ± 0.1, and its upper part has the shape of a hemisphere with a radius of 200 ± 3 mm.
[0026] The above-described cover, in one of its particular forms of execution, can have R from 160 to 200 mm.
[0027] The above-described cover, in one of its particular forms of execution, may have the mentioned upper part in the form of a spherical segment.
[0028] The above-described cover, in one of its particular forms of execution, may have the mentioned upper part in the form of a segment of an ellipse or paraboloid.
[0029] The above-described cover, in one of its particular forms of execution, may have the said upper and lower parts, made as a single unit. The above-described cover, in one of its particular forms of execution, may have the said upper part, provided with an inlet and outlet branch pipes, located horizontally.
[0030] The above-described cover, in one of its particular forms of execution, can have the above-mentioned pipes, equipped with metal bushings with internal threads for connection to pipelines.
[0031] The above-described cover, in one of its particular forms of execution, may have the above-mentioned threaded pipes, the distal part of which is formed by the helical line of the said metal sleeve, and the proximal part by the helical line of the said pipes.
[0032] The above-described cover, in one of its particular forms of execution, may have an outer surface of the said lower part provided with projections for interaction with the unscrewing equipment.
[0033] The above-described cover, in one of its particular forms of execution, may have on its inner side in the mating zone of the mentioned upper and lower parts an annular platform for placing a sealing ring.
[0034] The above-described cover, in one of its particular forms of execution, may have the mentioned means of connection, which are a thread located on the inner surface of the mentioned lower part.
[0035] The above-described cover, in one of its particular forms of execution, may have a wall thickness of the said upper part of approximately 5-6 mm, and a wall thickness of the lower part of approximately 5 mm.
[0036] The above-described cover, in one of its particular forms of execution, can have an increased wall thickness in the area where the upper and lower parts meet.
[0037] The above-described cover, in one of its particular forms of execution, may have the above-mentioned wall, provided with stiffening ribs, having a distal end connected to the said lower part, an upper end connected to the said central part and a middle part connected to the said wall.
[0038] The above-described cover, in one of its particular embodiments, may comprise at least five of the said stiffening ribs, at least some of which are located at an equal distance from each other.
[0039] The above-described cover, in one of its particular forms of execution, may have the mentioned stiffening ribs, forming cells of a polygonal shape, preferably triangular, quadrangular, trapezoidal, pentagonal or hexagonal.
[0040] The above-described cover, in one of its particular forms of execution, may have a thickness or height of the said stiffening ribs that decreases from the periphery to the center or decreases as the distance between the ribs increases.
[0041] The above-described cover, in one of its particular forms of execution, may have the said stiffening ribs located on the inner side of the wall of the said upper part.
[0042] The above-described cover, in one of its particular forms of execution, may have the said stiffening ribs located on the outer side of the wall of the said upper part.
[0043] The above-described cover, in one of its particular forms of execution, may have the said stiffening ribs located on the upper and lower side of the wall of the said upper part.
[0044] The above-described cover, in one of its particular forms of execution, may have the said stiffening ribs, adjacent to the said wall along its entire length and made in one piece with it. The above-described cover, in one of its particular forms of execution, may have the said stiffening ribs, made trapezoidal in cross-section for ease of removal from the casting mold.
[0045] The above-described cover, in one of its particular forms of execution, may have a thickness of the said stiffening ribs of at least 0.3 mm, and a height of at least 1 mm.
[0046] The above-described cover, in one of its particular forms of execution, may contain at least two nozzles.
[0047] The above-described cover, in one of its particular forms of execution, may comprise a central part having channels communicating with at least one of the mentioned pipes and with the internal cavity,
[0048] The above-described cover, in one of its particular forms of execution, may have a closing hole for releasing air.
[0049] The above-described cover, in one of its particular forms of execution, can be made of plastic, preferably polypropylene.
[0050] The above-described lid can be used to close the flask of a water filter similar to that described in Russian patents for utility models 168717 and 208898.
[0051] BRIEF DESCRIPTION OF DRAWINGS
[0052] Fig. 1 schematically shows a section of the head according to the present utility model.
[0053] Fig. 2 shows a photo of a sample product from the front, i.e. from the side of the inlet pipe.
[0054] Fig. 3 shows a photo of a sample product from the side (inlet pipe - on the left, outlet pipe - on the right). Fig. 4 shows a photo of a sample product from above. At the corners of the imaginary square, bosses with braces for fastening to the bracket are clearly visible.
[0055] Fig. 5 shows a photo of a sample of the product from below. The central part (round) and the stiffening ribs (diverging radially from the central to the peripheral part) are clearly visible.
[0056] Fig. 6 shows a section of the cover, the parameters of which were calculated using mathematical modeling.
[0057] Fig. 7 shows a graph illustrating the optimal and suboptimal (shaded zones Si and S2) locations of the filter cover dome cross-section from the standpoint of the strength-to-material intensity ratio. The average lines passing through the cover dome cross-section, with the optimal strength-to-material intensity ratio, should be monotonous lines located in the unshaded band between the suboptimal zones Si and S2.
[0058] IMPLEMENTATION OF THE INVENTION
[0059] As shown in Fig. 1-5, a cover for a water filter flask is shown, comprising: a lower part provided with means for connecting to the water filter flask, an upper part having a convex wall, the outer and inner surfaces of which are at least partially formed by bodies of revolution, characterized in that the ratio Si / S2 in it is from 0.5 to 0.37, where:
[0060] Si is the area of the part of square K located above the center line passing in the section of said wall at an equal distance from the outer and inner surfaces of the wall, S2 is the area of the part of square K located below the center line located in the section of said wall at an equal distance from the outer and inner surfaces of the wall, wherein square K lies in the secant plane, and its lower corner is located in the mating zone of the upper and lower parts of the cover at a distance R from its axis, and the upper corner is on its axis, and the shape of the section of said wall is such that between the upper and lower lines formed at the intersection of the secant plane with the outer and inner surfaces of said wall, a line with a radius of curvature varying in the range from 94 to 118% R can be inscribed.
[0061] During the study, optimal ratios of areas above and below the curve describing the center line of the cut plane of the filter housing cover were established, where the area Si relates to S2, within the range from 0.5 to 0.37.
[0062] It is most preferable when the area ratio Si / S2 is 0.4 ± 0.1 and the top has a spherical shape with a radius of curvature at any point of 200 ± 3 mm.
[0063] The shape and dimensions of the filter housing cover were experimentally determined to make it possible to achieve minimum material consumption and dimensions of the filter housing cover without reducing consumer qualities.
[0064] In order to determine the optimal ratio of Si to S2 in terms of material consumption, mathematical modeling of the strength characteristics was performed using the finite element method. The working load was taken to be a pressure of 8 bar applied to the inner edges of the cover shown in Fig. 6. The radius of the covers was 200 mm. All covers had a spherical surface without any kinks or local features. During the modeling, the wall thickness parameter (and, as a consequence, their mass) was varied in such a way as to ensure a safety margin of 1.0. A strength index higher than 1.0 means that the product does not break when the working load is applied, and an index lower than 1.0 means that the product may break when the working load is applied. The lower this index, the faster the failure will occur under the same operating conditions.
[0065] The simulation results are summarized in Table 1.
[0066] Table 1.
[0067] As we can see, at Si / S2 values less than 0.37, an excess safety margin is achieved simultaneously with high material consumption, and at values above 0.5, the material consumption is minimal, but the required safety margin is not ensured. Thus, the optimal values for a given wall thickness are Si / S2 values in the range from 0.37 to 0.5, which simultaneously provide a safety margin above 1.0 and satisfactory material consumption.
[0068] Adding stiffening ribs allows for a further reduction in the material consumption of the lid.
Claims
CLAUSE OF INVENTION 1. A lid for a water filter flask, comprising: a lower part provided with means for connecting to the water filter flask, an upper part having a convex wall, the outer and inner surfaces of which are at least partially formed by bodies of revolution, characterized in that the ratio Si / S2 in it is from 0.5 to 0.37, where: 51 - the area of the part of square K located above the center line passing in the section of the said wall at an equal distance from the outer and inner surfaces of the wall, 52 - the area of the part of square K located below the middle line located in the section of said wall at an equal distance from the outer and inner surface of the wall, wherein square K lies in the secant plane, and its lower corner is located in the mating zone of the upper and lower parts of the cover at a distance R from its axis, and the upper corner is on its axis, and the shape of the section of said wall is such that between the upper and lower lines formed at the intersection of the secant plane with the outer and inner surfaces of said wall, a line with a radius of curvature varying in the range from 94 to 118% R can be inscribed.
2. The cover according to claim 1, wherein the ratio Si / S2 is 0.4 ± 0.1, and the upper part has the shape of a hemisphere with a radius of 200 ± 3 mm.
3. The cover according to item 1, characterized in that R is from 160 to 200 mm.
4. The lid according to item 1, characterized in that the said upper part has the shape of a spherical segment.
5. The lid according to item 1, characterized in that the said upper part has the shape of a segment of an ellipse or paraboloid.
6. The cover according to item 1, characterized in that the said upper and lower parts are made as a single piece.
7. The cover according to item 1, characterized in that its said upper part is provided with inlet and outlet pipes located horizontally.
8. The cover according to item 5, characterized in that the above-mentioned pipes are equipped with metal bushings with internal threads for connection to pipelines.
9. A cover according to any of paragraphs 7 or 8, characterized in that the above-mentioned branch pipes have a thread, the distal part of which is formed by the helical line of the said metal sleeve, and the proximal part by the helical line of the said branch pipes.
10. The lid according to item 1, characterized in that the outer surface of the said lower part is provided with projections for interaction with the unscrewing equipment.
11. The cover according to item 1, characterized in that on its inner side in the mating zone of the said upper and lower parts there is an annular area for placing a sealing ring.
12. The lid according to item 1, characterized in that the said connecting means are a thread located on the inner surface of the said lower part.
13. The lid according to item 1, characterized in that the wall thickness of the said upper part is approximately 5-6 mm, and the wall thickness of the lower part is approximately 5 mm.
14. The cover according to item 1, characterized in that the thickness of the wall in the area where the upper and lower parts meet is increased.
15. The lid according to claim 1, characterized in that the above-mentioned wall is provided with stiffening ribs having a distal end connected to the said lower part, an upper end connected to the said central part and a middle part connected to the said wall 16. The cover according to claim 15, characterized in that it contains at least five of the said stiffening ribs, at least some of which are located at an equal distance from each other.
17. The cover according to item 15, characterized in that the said stiffening ribs form cells of a polygonal shape, preferably triangular, quadrangular, trapezoidal, pentagonal or hexagonal.
18. The cover according to item 15, characterized in that the thickness or height of the said stiffening ribs decreases from the periphery to the center or decreases as the distance between the ribs increases.
19. The cover according to item 15, characterized in that the said stiffening ribs are located on the inner side of the wall of the said upper part.
20. The cover according to item 15, characterized in that the said stiffening ribs are located on the outer side of the wall of the said upper part.
21. The cover according to item 15, characterized in that the said stiffening ribs are located on the upper and lower sides of the wall of the said upper part.
22. The cover according to item 15, characterized in that the said stiffening ribs are adjacent to the said wall along its entire length and are made in one piece with it.
23. The lid according to item 15, characterized in that the said stiffening ribs are made trapezoidal in cross-section for ease of removal from the casting mold.
24. The cover according to item 15, characterized in that the thickness of the said stiffening ribs is at least 0.3 mm and the height is at least 1 mm.
25. The cover according to item 1, characterized in that it contains at least two nozzles.
26. The cover according to I. 25, characterized in that it contains a central part having channels communicating with at least one of the mentioned pipes and with the internal cavity, 27. The lid according to item 1, characterized in that it is additionally provided with a closing opening for releasing air.
28. The lid according to item 1, characterized in that it is made of plastic, preferably polypropylene.
Citation Information
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