Vehicle seat having seat cushion

Abstract

The invention relates to a vehicle seat (1) having a backrest (3) and a seat portion (2), wherein the seat portion (2) has a cushion support (7), a cushion portion (9) arranged on the cushion support (7), and a cushion cover (10), wherein the cushion portion (9) is designed as a foam portion (9) and, at least in some portions, has a regular arrangement of recesses (11) having a polygonal base (19), wherein the recesses (11) are arranged on an underside of the cushion portion (9b) facing the cushion support (7) or on an upper side of the cushion portion (9a) opposite the underside, and the recesses (11) modify the properties of the foam portion (9), wherein the modification of the properties comprises at least a reduction in the spring hardness of the foam portion (9).

Description

[0001]HANNKE BITTNER & PARTNER PATENT ATTORNEYS AT LAW Prüfeninger Straße 1 93049 Regensburg GRAMMER Aktiengesellschaft July 8, 2025 Grammer-Allee 2 GRM01-486-WOPT 92289 Ursensollen HA / VO / Ne / sr Germany Vehicle seat with seat cushion Description The invention relates to a vehicle seat with a backrest and a seat section, wherein the seat section comprises a cushion support, a cushion section arranged on the cushion support, and a cushion cover. Vehicle seats, particularly for rail transport, are equipped with cushions to ensure the highest possible comfort for the occupant. In addition to the cushions, spring elements can also be provided, which additionally offer a spring effect for the occupant. Up to now, foam components for cushions designed for comfort have been soft but not very stable, or those designed for stability have been stable but hard.Therefore, foam components are often combined with spring elements such as coil springs in layers to ensure a high level of comfort. However, this layered construction requires increased design, manufacturing, and assembly effort, thus negatively impacting the cost of the vehicle seat. Consequently, the object of the invention is to provide a vehicle seat that overcomes the disadvantages of the prior art, in particular being more affordable, more stable, easier to maintain, and simpler to manufacture.To solve the problem, a vehicle seat according to the invention is provided, comprising a backrest and a seat section, wherein the seat section has a cushion support and a cushion section arranged on the HANNKE BITTNER & PARTNER GRM01-486-WOPT - 2 - cushion support and a cushion cover, wherein the cushion section is designed as a foam section and has at least a regular arrangement of recesses with a polygonal base, wherein the recesses are arranged on an underside of the cushion section facing the cushion support or on an upper side of the cushion section opposite the underside, and the recesses modify the properties of the foam section, wherein the modification of the properties comprises at least a reduction in the spring stiffness of the foam section. The vehicle seat has a seat section for sitting and a backrest for leaning against.In rail transport vehicle seats, such seats often have a base to which the seat cushion and backrest, or a supporting structure for both, are attached. It is also frequently provided that the seat cushion, or at least parts of it, can be moved translationally relative to the base or backrest. To ensure a high level of seating comfort and prevent seat fatigue, especially during long journeys, the seat cushion includes a padded section that dampens seat movements and, through deformation, distributes the occupant's weight across the entire seating surface. This padded section is made of foam, preferably entirely, and at least partially, made of a foam such as PUR foam, EPP, EPE, EPS, PET foam, or a similar material, or a mixture thereof.In particular, additives such as metals, minerals, oxides, ceramics, pigments, and dyes may be mixed into the foam component, influencing its appearance and / or physical properties. The padding is typically attached to and / or rests on a support structure, which carries and supports the padding. The support structure absorbs the force exerted on the padding by an occupant. The padding also has a top and a bottom. The bottom faces the support structure, and the top faces the occupant. An intermediate layer, particularly a non-woven or foam mat, may be arranged between the padding and the support structure to protect the padding from mechanical abrasion against the support structure. This intermediate layer may also secure the padding to the support structure.The upholstery section has a cover on its upper side, which protects it from abrasion and damage. Advantageously, the upholstery section is designed as a single piece, making it easily replaceable. In particular, the upholstery is the only significant spring element of the seat section. Damage from vandalism is a frequent problem in rail vehicle seats (HANNKE BITTNER & PARTNER GRM01-486-WOPT - 3). Therefore, parts of the vehicle seat must be replaceable with minimal effort, and in particular, the components should be as uniform and one-piece as possible. Preferably, the upholstery section is also free of additional frame or support structures. The foam section is elastic and can be deformed by a force. This force is usually exerted by the weight of an occupant. The foam section has a spring constant that is determined by the physical properties of the foam.The force exerted, particularly the weight of an occupant, and the spring constant of the foam component result in deformation of the foam. The extent of this deformation in the direction of the applied force is referred to as the indentation depth. This indentation, or deformation, is influenced by various properties of the foam component. The two most important properties are the density of the foam component, also known as its bulk density, and its indentation hardness. Bulk density indicates the weight of the foam component in cubic meters. The higher the value, the more raw material, especially polymer, was used in the production of the foam component. Bulk density is therefore a measure of the stability, resistance, and durability of the foam component. The higher the bulk density, the more stable and durable the foam component. For a vehicle seat, especially in rail transport, which is subject to intensive use, a high bulk density is therefore essential.However, the high density necessarily results in higher indentation hardness, as indentation hardness depends on the density and the modulus of elasticity of the plastic used. Indentation hardness, in turn, determines the compression depth, i.e., the deformation depth of the foam component under a specific load, as well as the spring action and comfort of the foam component. Therefore, stable, durable foam components with a high density are harder and less resilient than foam components with a low density, which are softer and more resilient. Properties that are altered by the cutouts include, in particular, aging behavior, compression behavior, and dimensional stability. The shape and design of the cutouts and the seat component improve aging behavior by reducing mechanical stress and the resulting abrasion, and by decreasing the spring hardness of the upholstery component.The spring stiffness of the upholstery also influences its sinking behavior and dimensional stability. The sinking behavior, and thus the sinking or seating depth, is an important indicator of how comfortable a cushion is. If the cushion is too soft, the occupant sinks in too deeply, which, due to the shifting of the pelvis, can lead to spinal misalignment and thus back pain. Additionally, this misalignment can place excessive strain on certain muscles, resulting in tension. If the seating depth is too shallow, meaning the upholstery is too firm, certain bones, especially the ischial tuberosities, are subjected to excessive stress, which can lead to fatigue and pain. The seating depth for a person weighing 80 kg is 25 mm to 40 mm, preferably 27 mm to 37 mm, and particularly preferably 30 mm to 35 mm.Dimensional stability is also an important characteristic of the upholstery. Especially in rail transport, seats are used for extended periods, either by a single passenger or by multiple passengers. The upholstery must maintain its comfort even after prolonged use and must not sag. Therefore, the upholstery must be both elastic and stable. To reduce the springiness of the foam and thus provide a durable, resilient, and soft upholstery, recesses are incorporated into the underside or top of the upholstery. These recesses create additional cavities within the foam, which initially reduces the effective density, thereby increasing the penetration depth and improving the springiness of the otherwise firmer foam.Preferably, the penetration depth for an occupant weighing 80 kg is greater than 25 mm, more preferably greater than 28 mm, and particularly preferably greater than 30 mm. According to a particularly preferred embodiment, the polygonal base is octagonal. An octagonal base for the recesses results in particularly advantageous adaptability of the seat cushion's properties, especially its sinking behavior and dimensional stability. Further advantages of the octagonal base are highlighted in the course of this description. According to a particularly preferred embodiment, the recesses are arranged according to a Bravais grid, wherein the Bravais grid is square or centered rectangular and the recesses are located on the grid points of the Bravais grid. HANNKE BITTNER & PARTNER GRM01-486-WOPT - 5 - A regular arrangement of the recesses is important for a uniform spring effect.The arrangements are preferably arranged in a lattice structure, in particular according to a Bravais lattice. Bravais lattices describe a translationally symmetric point lattice, especially for crystals. Each point indicates a location where a so-called basis is located, which can consist of one or more atoms. Each location in the crystal where a basis is located is represented by the sum of integer multiples of the primitive vectors, one for each dimension. Thus, each atom is assigned a unique position in the crystal. This can also be transferred to the two-dimensional arrangement of the recesses according to the invention, wherein the recesses are arranged on the lattice points.Accordingly, the cutouts are arranged either in a checkerboard pattern consisting of equal-sized squares, with the center point of the base of a cutout located at each corner of the squares, or in a checkerboard pattern consisting of equal-sized rectangles, with the center point of the base of a cutout located at the corners and center points of the rectangles. These two arrangements are the square and the centrally located rectangular Bravais grids. In particular, the Bravais grid is mapped onto the surface, most preferably onto the top or bottom of the cushioning part. The cutouts need not extend over the entire surface. Preferably, the cutouts are arranged only in a partial area of ​​the cushioning part, with this partial area extending largely over the entire top or bottom surface.According to one embodiment, several different grid structures can also be arranged in different areas of the upholstered part. According to a particularly preferred embodiment, a primitive vector of the Bravais grid runs at 45°. The vehicle seat's longitudinal direction X, width direction Y, and height direction Z are understood to be a Cartesian coordinate system X, Y, Z. If one imagines a vehicle seat L-shaped, with the backrest as the first leg and the seat as the second leg, Z is oriented along the principal direction of extension of the backrest and thus, in particular, along the principal direction of extension of the entire vehicle seat. X is oriented along the second leg, or rather, along the normal to the front of the backrest facing the occupant. The vehicle seat's width direction Y is oriented along the second direction of extension of the backrest and the seat.Typically, the seat and backrest sections are not orthogonal to each other. In this case, the seat and / or backrest sections are rotated at an angle to the vehicle seat height direction around the vehicle seat width direction. For a square Bravais grid, such an arrangement at a 45° angle results in the recesses being arranged in rows along the longitudinal direction X of the vehicle seat, with each subsequent row offset by half the distance between two recesses in a row along the seat width direction Y. This results in a diamond-shaped arrangement of the recesses. According to a particularly preferred embodiment, a rectangular or square island is formed between each group of four adjacent recesses, with each island being connected to one of the four adjacent islands by a bridge.Due to the advantageous octagonal shape of the recesses and their regular arrangement, for example according to the aforementioned Bravais grids, four adjacent recesses enclose an island. Since the recesses do not directly abut each other, each island is in turn connected to four other islands by narrow bridges. This, of course, only applies as long as there are adjacent recesses and islands, and therefore not at the edges of the regular arrangement of recesses. The islands can be approximated as hexahedral, cuboidal, or truncated pyramidal shapes with a square base, and the bridges as hexahedral, cuboidal, or truncated pyramidal shapes with a rectangular base. The bridges are advantageously much narrower and shorter than the islands and connect the islands, in particular, along a straight line.Advantageously, with the regular arrangement of octagonal recesses, the areas of the ribs are smaller in relation to the areas of the islands than for triangular, quadrilateral, pentagonal, or hexagonal recesses. If the recesses are considered as free space and the islands and ribs as foam bodies, then the islands are spring elements connected to neighboring spring elements via the ribs. As previously described, a foam component with high density and indentation hardness is preferably used, as this is particularly resistant. The high indentation hardness of the foam component is accordingly represented by a high spring stiffness. If an island or a spring element is compressed, it transfers a portion of the force acting upon it via a tensile force along the ribs to the neighboring spring elements, which are consequently also compressed.Typically, the spring elements are round or circular, causing the bridges between the islands to be concave, or they are triangular, quadrilateral, pentagonal, or hexagonal. In the case of triangular, quadrilateral, pentagonal, or hexagonal spring elements, the bridges are generally so wide that they are barely distinguishable from the islands or are similar in size to the islands, so that they themselves have a significant spring effect and can be considered independent spring elements. In the case of round or circular islands—this also includes ovals—the tensile force is deflected by the concave shape of the bridges not only towards the next island but also perpendicular to it. This results in less compression of the adjacent islands, ultimately leading to a higher spring stiffness of the entire foam component.The octagonal, preferably regularly octagonal, basic shape, with its narrow, straight, or flat ribs, ensures that when an island formed between the octagonal recesses is compressed, the resulting tensile forces on the ribs are linearly transferred to the adjacent islands. This advantageously causes the neighboring islands to collapse more easily, thereby reducing the indentation hardness and increasing the insertion depth. In a particularly preferred embodiment, the polygonal recesses each taper conically towards one end, with the edges of the recesses being rounded and the ends of the recesses being formed as spherical segment-shaped radii. The recesses can be created, for example, by machining or by foaming a mold.During the foaming process, the foam part releases more easily from the mold, or rather, it is less likely to be damaged during removal, if the shape of the recesses has few sharp angles. Rounded edges thus prevent the foam part from tearing out. A conical shape for the recesses also facilitates release from the mold. In this case, the recesses taper to an end opposite the polygonal base. Specifically, this end lies within the foam part, while the polygonal base rests on the surface of the foam part. HANNKE BITTNER & PARTNER GRM01-486-WOPT - 8 - In addition to the aforementioned advantages of ease of removal, the rounded edges also ensure that peak forces at edges or corners are reduced if the foam part is deformed.Such peak forces often cause the foam section to tear at the affected corners and edges, which negatively impacts its spring action. Over time, the cracks spread throughout the foam section, ultimately rendering it unusable. Furthermore, the conical shape of the islands between the recesses causes them to widen the further one is from the surface of the foam section. This has the advantageous effect that, as the islands widen, the spring stiffness is not linear but increases with compression. This prevents the feeling of sagging or actual sagging of the upholstery. In one embodiment, the recesses are located on the underside of the foam section, with the foam section being loaded from the opposite top side.In this case, the spherical segment-shaped radii at the ends of the recesses have the advantage of acting as domes or cupolas, which transfer the forces to the surrounding walls, i.e., webs and islands. The recesses can therefore also be referred to as cupolas. According to a particularly preferred embodiment, the recesses extend substantially parallel to a vehicle seat height direction Z. Since the recesses define the islands, and these are considered spring elements, it is advantageous if the main axis of extension, and thus the height of the cupolas, is aligned with the direction of the force acting on the spring elements. Since the force on the foam part is caused by the force of gravity, which is aligned with the vehicle seat height direction, the recesses are also arranged substantially parallel to it. "Substantially" in the context of this description means including usual manufacturing and assembly tolerances.According to a particularly preferred embodiment, the ratio of the maximum diameter of the base of a recess to the distance between the centers of the bases of two recesses is less than two to three. HANNKE BITTNER & PARTNER GRM01-486-WOPT - 9 - Since the size of the islands is determined by the distance between the centers of two recesses and their diameters, an advantageous size for the spring elements and also for the webs can be determined by their ratio. This ratio allows the islands to collapse easily, thus forming an advantageous spring effect. The size of the recesses determines the size of the islands and, as the area of ​​the spring element, also its spring constant. According to a particularly preferred embodiment, the ratio of the maximum diameter of the base of a recess to the height of the recess is less than one to one.In this context, height can also be understood as depth, depending on whether the recesses are located on the top or bottom of the upholstery section. Specifically, height should be defined as the extent of the recess parallel to the vehicle seat height axis Z. The height of the recesses affects the seat depth. Along the vehicle seat height axis, the foam section after the recesses is preferably designed as a solid foam section. This results in a significantly higher spring rate in the solid area than in the area with the recesses. Consequently, the height of the recesses has a significant influence on the seat depth of the upholstery section. The height of the recess also determines the height of the island and thus, as the length of the spring element, its spring rate.In a particularly preferred embodiment, the ratio of the maximum diameter of the base of a recess to the maximum diameter of the spherical segment end is greater than four to three. The angle at which the recess tapers conically is determined by the ratio of the base area to the top area, which corresponds to the maximum diameter of the spherical segment end. This, in turn, determines how much the size of the recess changes with the height of the recess and thus how much the spring stiffness changes with the insertion depth. In one embodiment, the recesses in different areas of the seat can be shaped differently, for example, softer in the area of ​​the ischial tuberosity than in a surrounding area. Preferably, however, all recesses in HANNKE BITTNER & PARTNER GRM01-486-WOPT - 10 - essentially have the same dimensional ratios described above.In particular, the recesses are simply reduced or enlarged by a factor to obtain a different spring stiffness. According to a particularly preferred embodiment, a cover pad is arranged between the upholstery part and the upholstery cover, wherein the cover pad at least partially encloses the upholstery part or has a recess in which the upholstery part is at least partially arranged. According to a preferred embodiment, the upholstery part can be divided into two areas along a vehicle seat height direction: a first area comprising the recesses and a second area designed as a solid foam part, i.e., having only the natural pores and no recesses. Preferably, both areas are formed in one piece as a single foam part, with the second area being thinner than the first area.A cover pad adds another layer to the upholstery, protecting it from abrasion and increasing comfort. The cover pad can either completely cover the upholstery or, more specifically, have a recess on its underside (the side facing the upholstery) into which the cover pad is inserted. This creates a box-like fit, ensuring at least a partial seal. The cover pad and / or the second section, which is made of solid foam, also influence the firmness of the seat cushion. The cover pad or this section can vary in thickness or be made of different types of foam in different locations, such as the front or back of the seat. This allows the firmness of the seat cushion to be adjusted by modifying the firmness of the cover pad or the second section.In one embodiment, the polygonal recesses extend completely through the foam part, thus forming a passage from the top to the underside of the foam part. Preferably, in this embodiment, the seat part has a cover cushion. In a particularly preferred embodiment, the cushion support is shaped like a shell and extends substantially in the longitudinal direction X of the seat and in a lateral direction Y of the seat. HANNKE BITTNER & PARTNER GRM01-486-WOPT - 11 - The shell-shaped design of the cushion support allows forces acting on the cushion part to be distributed evenly across the cushion support. Preferably, the underside of the cushion part and the opposite upper side of the cushion support are largely flat, with the planes extending perpendicular to the vehicle seat's vertical axis Z.Advantageously, this allows for uniform deformation of the foam component under uniform load. A fleece or a silicone or foam mat can also be arranged between the upholstery component and the upholstery support, protecting the upholstery support from abrasion against the support. According to a particularly preferred embodiment, a first surface, which essentially forms the top of the upholstery component, is contrasted with a second surface, which essentially forms the back. The upholstery component can be narrower in a rear area, which is closer to the backrest, than in a front area, which is further away from the backrest. This results in a rearward slope of the top of the upholstery component, which reduces occupant fatigue by providing a more comfortable sitting position. Further advantageous embodiments are described in the dependent claims and the following description in conjunction with the drawing. Figures show:Fig. 1 shows an overall view of a vehicle seat according to the invention; Fig. 2 shows an exploded view of a seat part according to the invention; Fig. 3 shows a bottom view of a foam part according to the invention; Fig. 4 shows a bottom view of a cushion support according to the invention; Fig. 5a shows a section through a foam part according to the invention at a 45° angle to the longitudinal direction X; Fig. 5b shows a section through a foam part according to the invention parallel to the lateral direction Y; Fig. 6a shows a section through a mold for producing a foam part according to the invention; Fig. 6b shows a recess according to the invention in negative view; and Fig. 7 shows a bottom view of an arrangement of recesses according to the invention. For clarity, some reference numerals have been omitted in the figures. Figure 1 shows a vehicle seat 1 according to the invention in a double seat configuration, that is, two vehicle seats 1 side by side which are mounted on a common base 6.The vehicle seat has a seat section 2 that extends primarily in a longitudinal direction X and a width direction Y, and also extends to a small extent along the height direction Z. A back section 3 is arranged in an L-shape relative to the seat section 2, extending primarily in the height direction Z and width direction Y. A headrest 5 is attached to the upper end of the back section 3, and an armrest 4 is attached to each side next to the backrest 3. Figure 2 shows an exploded view of a seat section 2 of a vehicle seat 1 according to the invention. From bottom to top, a support cushion 7 in the form of a support shell 7 is arranged first. The upper surface of the support shell 7 is largely flat. A nonwoven fabric 8 is arranged over this, covering the flat upper surface of the support shell 7. A cushion section 9 rests on the nonwoven fabric and is covered with a cushion cover 10.The support shell 7 forms the support structure for the seat part 2 according to the invention and is a hard plastic shell. The fleece 8, which rests on the support shell 7, forms a separating layer between the hard shell 7 and the upholstery part 9 in order to reduce abrasion caused by alternating loading and unloading of the upholstery part 9. This is particularly necessary because the upholstery part 9 is made of polyurethane as a soft foam part 9, with expanded graphite added to the polyurethane as a flame retardant. The underside of the foam part 9 is also largely flat, with the exception of the recesses (not visible here), but has a border on the sides and especially on the front, which extends around the entire foam part 9 except for the back.This rim partially encloses the support shell 7 and thus serves, on the one hand, to fix the foam part 9 to the support shell 7 and, on the other hand, to provide padding for the sides and, in particular, the front of the support shell 7 facing an occupant. The upper surface of the foam part 9a is slightly convex around the lateral direction Y. Furthermore, the upper surface of the foam part 9a is inclined upwards by 5° relative to the underside of the foam part 9b, so that a front area of ​​the seat section 2 is higher than a rear area. Finally, the entire upper surface of the foam part 9 is covered with a cover 10, which is attached to the underside of the support shell 7b. Figure 3 shows the underside of the foam part 9b. The flat central area is almost completely covered with the octagonal recesses 11. The rim surrounding the central area is visible at the front and sides. The back of the foam part 9 is slightly beveled.The recesses 11 are arranged in a square Bravais grid with the primitive vectors a1 and a2. a1 and a2 run at angles of +45° and -45°, respectively, to the longitudinal direction X. The recesses 11 also have a regular octagonal base 19. The grid of recesses is created by translating the elementary mesh 12 by integer multiples of the primitive vectors a1 and a2 in each of the two directions in which the vectors a1 and a2 point. Naturally, the multiples can also be negative, so that the elementary mesh is translated in the opposite direction to at least one of the two directions in which a1 or a2 point. The grid of recesses is arranged almost across the entire underside of the foam part 9b. This ensures uniform cushioning for the entire upholstery part 9. Figure 4 shows the underside of a support shell 7b.The support shell 7 has rows of attachment points 13 for adjustment rails or sliding elements. A corresponding counterpart is then mounted on the base, allowing the seat section 2 to be moved relative to the back section 3 in a longitudinal direction X. The support shell also has a rim that runs along the sides and, in particular, the front. When the seat section 2 is assembled, the rim of the foam section 9 lies flush with the rim of the support shell 7. Thus, the rim of the foam section 9 and the rim of the support shell 7 form a partial interlock, which helps to fix the foam section 9 to the support shell 7. The support shell 7 is made of polypropylene. To attach the HANNKE BITTNER & PARTNER GRM01-486-WOPT - 14 - upholstery cover, hooks 14 are formed on the rim of the support shell, over which the upholstery cover is stretched.The upholstery and the edging of the foam part 9 ensure that the foam part is held on the support shell 7. Figures 5a and 5b show two sections through a foam part according to the invention. Figure 5a shows a section along a plane parallel to the vertical direction Z and the primitive vector a1, while Figure 5b shows a section parallel to the horizontal direction Y and the vertical direction Z. Both sections also pass through the centers of several recesses 11. In Figure 5a, the recesses are arranged only in a rear region of the seat part 2, above which the center of gravity of an occupant is typically located. A front region, however, is free of recesses 11. Only the thighs of an occupant rest on this region, which is why the foam part is harder here than in a rear region.The recesses 11 extend from the underside of the foam part 9b towards the top side of the foam part 9a, although the top side 9a does not have any recesses 11. The ratio of the height of the recesses to the thickness of the foam part 9, i.e., the thickness of the foam part between the underside 9b and the top side 9a, is less than six to one. This ensures that a sufficiently thick, continuous top layer 15 of foam is present on the top side 9a, so that the ribs 16 and islands 17 are sufficiently connected to prevent damage under load. In addition, the top layer 15 forms a first uniform cushioning layer, which prevents the recesses 11 from pressing through under load, or from an occupant feeling the recesses 11. The section in Figure 5a runs parallel to the primitive vector a1.In this view, the recesses 11 are arranged in rows one behind the other. Between two adjacent recesses 11, narrow ribs 16 are formed, which are significantly smaller than the recesses 11. The section in Figure 5b runs parallel to the width direction Y. From this perspective, the recesses 11 are arranged in a checkerboard pattern, meaning that the next row of recesses 11 is always offset by half the distance between two recesses 11 in the width direction Y. Between each recess 11, an island 17 can be seen, which is approximately the same size as a recess 11. The recesses extend over the entire width of the foam part 9, forming a small edge area at the sides. All solid areas and layers, i.e. areas and layers in which no recesses 11 are arranged, increase the HANNKE BITTNER & PARTNER GRM01-486-WOPT - 15 - stability of the foam part 9.The recesses also taper noticeably in the vertical direction Z, becoming narrower. This also means that the islands 17 are thicker towards the top 9a than towards the bottom 9b. Figure 6 shows a section along an XZ plane through a mold 18 for manufacturing, tilted 3° backwards relative to the bottom of the mold 18, i.e., opposite the longitudinal direction X. As a result, the finished foam part 9 is higher at the front than at the rear. However, the recesses 11 remain aligned parallel to the vertical direction Z. Analogous to Figure 5b, the shapes for the recesses are also arranged in a checkerboard pattern in this section. A step can be seen in the front area of ​​the mold 18, which later forms part of the rim of the foam part 9. Figure 6b shows a mold for a [missing information - likely a specific type of mold]. Since the two bodies are identical in an isometric view, the terms can be used interchangeably.The recess 11 initially has a uniformly octagonal base 19. The corners of the base are rounded. The base area tapers upwards, becoming smaller than the base area 19. Starting from the octagonal intermediate surface 19, the lateral surfaces 21 of the recess 11, initially still octagonal, taper conically until they merge into a circular ring 22, which is smaller in diameter than the intermediate spherical segment 23 that adjoins the circular ring 22. All edges and corners of the recess 11 are thus rounded, which prevents the foam part from tearing out when it is removed from the mold 18 and also prevents the foam part 9 from tearing at the recesses 11 under load due to force peaks. Despite the rounded edges, the recess 11 largely has the shape of a truncated pyramid with an octagonal base. Figure 7 shows a bottom view of an arrangement of recesses 11 according to the invention.The top view of the recesses 11, as shown in Figure 6b, also clearly illustrates this structure. From the outside in, the octagonal base 19 tapers conically via the recess into the octagonal intermediate surface (HANNKE BITTNER & PARTNER GRM01-486-WOPT - 16) and finally terminates with the spherical segment 23. Four adjacent recesses 11, arranged in a cross shape, enclose an island 17 in their center. Each island 17 is connected to neighboring islands in a cross shape via bridges 16. Because the recesses 11 taper conically, the islands 17, which have a square base, have a top surface at the level of the ring 22 that is more than one and a half times the size of the base. This is also clearly visible in Figure 5b. Island 17 can also be seen as a truncated pyramid with a square base and top surface.The islands 17 form truncated pyramid-shaped spring elements 17, whose spring stiffness increases with increasing compression due to their pyramidal shape. Each spring element 17 is connected to an adjacent spring element 17 via a web 16, parallel to either the primitive vector a1 or a2. Each spring element 17 that is not located at the edge of the grid is thus directly coupled to four other spring elements 17 in a cross-like configuration. Forces between the spring elements 17 act only parallel to the primitive vectors a1 and a2, or at an angle of +45° or -45° about the vertical direction Z to the longitudinal direction X. When one of the spring elements 17 is loaded, the adjacent spring elements 17 are also compressed, depending on the load. The force acting on the spring element 17 compresses, due to the checkerboard arrangement of the recesses 11, adjacent spring elements at an angle of 45° to the longitudinal direction X.Due to this arrangement, the spring elements 17 are coupled to a varying number of other spring elements, depending on their position in the grid. Thus, spring elements 17 at the edge of the grid are coupled to fewer spring elements 17 than those arranged in the center of the grid. Four islands 17 and four webs 16 also enclose an octagonal recess 11 in a loop-like fashion. When one of the islands 17 is compressed, the recess 11 is stretched in the direction of the compressed island 17 and simultaneously compressed transversely to it. Under this deformation, the recess 11 collapses, that is, it falls in on itself, deforming into a slit-like shape. The octagonal shape of the recesses 11 facilitates their collapse along the edges of the shell 21.The edges of the mantle thus form a kind of fold, at which mantle surfaces 21 preferably bend towards each other, thereby facilitating deformation of the recesses 11 and thus advantageously reducing the spring stiffness of the foam part 9.HANNKE BITTNER & PARTNER GRM01-486-WOPT - 17 - Reference Symbol List 1 Vehicle seat 2 Seat section 3 Back section 4 Armrest 5 Headrest 6 Foot 7 Upholstery support 7a Top of upholstery support 7b Bottom of upholstery support 8 Intermediate layer 9 Upholstery section 9a Top of upholstery section 9b Bottom of upholstery section 10 Upholstery cover 11 Recess negative of a recess 12 Element mesh 13 Attachment points 14 Hook 15 Cover layer 16 Bridge 17 Island 18 Shape of foam section 19 Octagonal base Octagonal intermediate surface 20 Recess 21 Lateral surfaces 22 Circular ring 23 Spherical segment a1 primitive vector a1 a2 primitive vector a2 X Vehicle seat longitudinal direction HANNKE BITTNER & PARTNER GRM01-486-WOPT - 18 - Y Vehicle seat width direction Z Vehicle seat height direction.

Claims

HANNKE BITTNER & PARTNER GRM01-486-WOPT - 19 - Vehicle seat with seat cushion Patent claims 1. Vehicle seat (1) with a backrest (3) and a seat section (2), wherein the seat section (2) comprises a cushion support (9) and a cushion section (9) arranged on the cushion support (7) and a cushion cover (10), characterized in that the cushion section (9) is designed as a foam section (9) and has at least a regular arrangement of recesses (11) with a polygonal base (19), wherein the recesses (11) are arranged on an underside of the cushion section (9b) facing the cushion support (7) or on an upper side of the cushion section (9a) opposite the underside (9b) and the recesses (11) modify the properties of the foam section (9), wherein the modification of the properties comprises at least a reduction in the spring hardness of the foam section (9). 2.

1. Vehicle seat (1) according to claim 1, characterized in that the polygonal base is an octagonal base.

2. Vehicle seat (1) according to any one of the preceding claims, characterized in that the recesses (11) are arranged according to a Bravais grid, wherein the Bravais grid is square or centered rectangular and the recesses (11) are located on the grid points of the Bravais grid.

3. Vehicle seat (1) according to claim 3, characterized in that a primitive vector (a1, a2) of the Bravais grid is used. ahrzeugsitz HANNKE BITTNER & PARTNER GRM01-486-WOPT - 20 - 5. Vehicle seat (1) according to one of the preceding claims, characterized in that a rectangular or square island (17) is formed between each set of four adjacent recesses (11), each island being connected to one of the four adjacent islands (17) by a bridge (16).

6. Vehicle seat (1) according to one of the preceding claims, characterized in that the polygonal recesses (11) each taper conically towards one end, the edges of the recesses (11) being rounded, the ends of the recesses (11) being formed as spherical segment-shaped radii (23).

7. Vehicle seat (1) according to one of the preceding claims, characterized in that the recesses (11) extend substantially parallel to a vehicle seat height direction Z. 8.

9. Vehicle seat (1) according to any one of the preceding claims, characterized in that the ratio of a maximum diameter of the base (19) of a recess to the distance between the centers of the base (19) of two recesses (11) is less than two to three.

10. Vehicle seat (1) according to any one of the preceding claims, characterized in that the ratio of a maximum diameter of the base (19) of a recess to a height of the recess is less than one to one.

11. Vehicle seat (1) according to claim 6, characterized in that the ratio of a maximum diameter of the base (19) of a recess to a maximum diameter of the spherical segment-shaped end (22) is greater than four to three. HANNKE BITTNER & PARTNER GRM01-486-WOPT - 21 - 11. Vehicle seat (1) according to any of the preceding claims, characterized in that a cover cushion is arranged between the upholstery part (9) and the upholstery cover (10), wherein the cover cushion at least partially encloses the upholstery part (9) or has a recess in which the upholstery part (9) is at least partially arranged.

12. Vehicle seat (1) according to any of the preceding claims, characterized in that the upholstery support (7) is shell-shaped and extends substantially in the longitudinal direction X of the seat and in a width direction Y of the seat.

13. Vehicle seat (1) according to claim 12, characterized in that a first surface, which substantially represents the upper surface of the upholstery part (9a), is inclined at an angle to a second surface, which substantially represents the upholstery support (7), wherein the angle is greater than 0° and less than 15°.

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