Backrest with a convex support surface and method for producing the backrest

Abstract

A backrest 1 for a vehicle seat is proposed, comprising a backrest base body 2 which has a lumbar vertebrae region 3 and a thoracic vertebrae region 4 adjoining the lumbar vertebrae region 3 in the vertical direction HR, with a surface line 9 arranged in the transverse direction QR centrally of the lumbar vertebrae region 3 and the thoracic vertebrae region 4, with a transverse line 7 delimiting the thoracic vertebrae region 4 in the vertical direction HR, wherein a support surface 10 of the thoracic vertebrae region 4, in a cross-section viewed in the vertical direction HR, has an increasingly convex curvature 11 with increasing vertical direction HR, the apex 13 of which curvature lies on the surface line 9, wherein the surface line 9, viewed in the transverse direction QR, has a curved and / or concave profile rising from the transverse line 7 towards the vertical direction HR in a sitting direction SR.

Description

Technical Field:The invention relates to a backrest for a vehicle seat having the features of the preamble of claim 1.Background:Vehicle seats are known which enable the occupant an ergonomic seating position by means of various adjustment options and an adapted seat geometry. In this case, the seat surface is shaped in such a way that specific regions of the human body are specially supported in order to accommodate the human body in the seat in a posture that is as natural as possible, derived from the standing position. Thus, a certain curvature in the region of the lumbar vertebrae, also called lordosis support, causes support of the spinal column during sitting. The lumbar support supports the iliac crest and lumbar vertebrae such that the pelvis cannot rotate backwards or can be rotated to a lesser extent during sitting.By seating and leaning the upper back against the seat back, the shoulder leaves are also pressed more or less strongly forwards or the thoracic vertebrae are pressed backwards relative to the shoulder leaves. This results from the fact that the shoulder blades often protrude rearward beyond the thoracic vertebrae when standing. Due to this forced positioning of the skeleton in the upper back region, the shoulders are pulled forward and downward and the cervical vertebrae extend or decrease the sternum and the thoracic cavity is reduced. All of these consequences may possibly lead to muscle tension and consequently to muscle fatigue and / or blood flow disorders and / or reduced lung volume and resultant flatter breathing, etc.The document EP 1 351 839 B1 discloses a seat, in particular for a vehicle, with a cushioned seat surface and a cushioned seat, wherein the backrest forms a rib cage support which is limited to a central region on both sides of the spinal column of a user, with cushioning sections which are set back relative to the rib cage and / or are resiliently flexible laterally adjoining said support sections, wherein the backrest has a cross section in the contact region of the rib cage with a substantially straight front boundary or which is curved forward relative to the spinal column region, whereby with increasing lateral distance from this rib cage support an increasing clearance of the rib cage results.Description:The object of the invention is to propose a backrest for a vehicle seat which ensures large-area ergonomic contact of the back with the backrest.This object is achieved by a backrest having the features of claim 1 and by a method having the features of claim 7. Preferred or advantageous embodiments of the invention are evident from the dependent claims of the following description and / or the attached figures.The subject matter of the invention is a backrest which is designed and / or suitable in particular for a vehicle seat. The backrest is preferably designed and / or suitable for a driver seat, passenger seat and / or rear seat of a vehicle. Alternatively, however, the backrest can also be designed and / or suitable for seating furniture, such as an office chair, for example. An optional subject matter of the invention relates to a vehicle seat with the backrest.The backrest has a backrest base body. The backrest base body is preferably formed as a backrest cushion, in particular a back cushion. The back cushion may be formed of a foam material or other elastically resilient material. The backrest cushion is preferably formed from a one-part backrest foam, a multi-part backrest foam, e.g. base foam and cut foam, a multizone foam, e.g. one zone with hard foam and another zone with soft foam, or an in situ foam, e.g. a foamed-out cover bag. Alternatively, the leg base body can be formed from a one- or multi-part backrest part made of a solid material, such as e.g. plastic, metal, wood, etc. The backrest base body is arranged in particular on a backrest frame, wherein the backrest frame forms an optional component of the backrest.The backrest base body has a lumbar region, also called a lordosis region, and a thoracic region adjoining the lumbar region in the vertical direction. In particular, the lumbar region is to be understood as the region of the backrest on which the user's back, preferably the lumbar spine, is supported. Preferably, a lordosis support is formed in the lumbar vertebra region. In particular, the thoracic vertebra region is to be understood as the region of the backrest on which the upper back, preferably the thoracic vertebra column, of a user is supported. In particular, the lumbar region and the thoracic region are manufactured from a common material section, preferably in one piece. Alternatively, however, the lumbar region and the thoracic region can also be formed from two different material sections and / or in multiple parts. Optionally, the backrest cushion can have side cheek regions adjoining the lumbar region and the thoracic vertebra on both sides and / or a cervical vertebra region adjoining the thoracic vertebra region in the vertical direction.The backrest has a surface line arranged centrally in the transverse direction of the lumbar region and of the thoracic region. In other words, the surface line is to be understood as a line of symmetry or center line of the backrest. In particular, the surface line follows a surface profile of the backrest, in particular of the lumbar region and of the thoracic region, in the vertical direction. Preferably, the surface line extends over the entire height of the backrest, that is to say also, if appropriate, over the cervical vertebra region.The backrest has a transverse line which delimits the thoracic vertebra region in the vertical direction. In particular, the transverse line is to be understood as an imaginary or theoretical delimitation of the thoracic vertebra region. In principle, however, the transverse line can also coincide with and / or be defined by a physical delimitation of the thoracic vertebra region, such as e.g. a stitching channel for reference fastening. In particular, the transverse line follows a surface profile of the backrest, in particular of the thoracic region, in the transverse direction. Preferably, the transverse line intersects the surface line at right angles. Specifically, the thoracic region and the cervical region are separated by the transverse line. The vertical direction and the transverse direction relate here to a Cartesian coordinate system, preferably a local vehicle coordinate system.In the context of the invention, it is proposed that a supporting surface of the thoracic vertebra region, in a cross section viewed in the vertical direction, has an increasingly convex curvature with an increasing vertical direction, the apex of which curvature lies on the surface line. In particular, "increasing in the vertical direction" is to be understood such that the convex curvature increases continuously and / or continuously in the vertical direction. In other words, the supporting surface has an overbove which increases in the vertical direction and is formed to be the greatest at the location of the upper delimiting transverse line. The change in the curvature can preferably be constant. In particular, the support surface is to be understood as the part of the thoracic region on which the upper back of a user is or can be supported flat, in particular over the entire surface. Shown in simplified form, the support surface relates to that part of the thoracic region against which the spinal column and the two shoulder blades rest. In particular, the support surface extends over more than 50%, preferably more than 70%, in particular more than 80% in the vertical direction of the entire thoracic vertebra region. Alternatively, the support surface extends over the entire thoracic region.Furthermore, it is provided that the surface line, viewed in the transverse direction, has a curved and / or concave profile which increases from the transverse line counter to the vertical direction in a seating direction. In particular, "rising against the vertical direction" is to be understood such that the course of the surface line in the region of the supporting surface increases continuously and / or continuously in the seating direction. In other words, the surface line has an increasing curvature in the direction of the lumbar vertebra region. Shown in simplified form, the support surface has an increasingly convex shape when viewed in the vertical direction and an increasingly concave shape when viewed in the transverse direction. Preferably, a depression or a cavity is thus formed in each case in the region of the shoulder blades, so that the shoulder blades are supported on the support surface offset with respect to the spinal column.The invention is based on the concept of a full-surface support of the upper back, in particular of the spinal column and of the shoulders, which is realized by an ergonomically shaped contouring of the backrest similar to the lordosis support. As a result, different support heights are achieved in the region of the upper back, which support heights are adapted to the anatomical shape of the human body. In this case, the region of the spinal column is supported more, whereas a type of cavity is formed for the shoulder blades. This special geometry ensures that the back lies almost completely against the backrest. Due to the increasing convex curvature, the different support heights can be realized in a simple manner, with the advantage that no disturbing contours, such as edges, cowps or the like, are formed. Thus, a targeted and body-appropriate support of the thoracic vertebrae as well as a natural posture of the shoulders relative to the thoracic vertebrae can be realized. In combination with the lumbar spine, the natural shape of the spine can also be produced. As a result of the continuous course, moreover, seat functions and equipment features, such as massage, seat heating, etc., can be realized without impairing their construction.In a concrete embodiment, it is provided that the thoracic vertebra region has side lines delimiting on both sides in the transverse direction, wherein the curvature ends of the convex curvature lie on the side lines. In other words, the convex curvature extends over the entire width of the thoracic vertebra region. In particular, a curvature end is to be understood as the point at which the convex curvature ends or changes. Preferably, the support surface is defined between the transverse line and the side lines or the surface line. In particular, the side lines are to be understood as imaginary or theoretical lateral boundaries of the thoracic vertebra region. In principle, however, the side lines can also coincide with a physical delimitation of the thoracic vertebra region, such as the sticking channel, for example, and / or be defined by these. In particular, the side lines follow a surface profile of the backrest, in particular of the thoracic vertebra region and of the lumbar vertebra region, in the vertical direction. In other words, the side lines can also be understood as lateral surface lines. In particular, the thoracic vertebra region and the two side cheek regions are each separated by a side line. The convex curvature over the entire width of the thoracic vertebra region can produce a particularly gently shaped curvature which does not form a disturbing contour or is perceived as disturbing by the user.In a further specific embodiment, it is provided that a maximum distance between the apex of the convex curvature and a connecting line connecting the curvature ends is more than 4 mm and / or less than 12 mm, preferably 8 mm. In particular, the maximum height is defined by a height difference, viewed in the vertical direction, between the centrally arranged surface line and one of the side lines. Preferably, the maximum height is the greatest at the location of the upper transverse line. Particularly preferably, the height or the height difference decreases continuously and / or constantly counter to the vertical direction. In particular, the connecting line extends parallel and / or in the same direction as the transverse direction. Optionally, the support surface resulting from the convex and concave curvature can have a surface tolerance of at least or exactly + / - 1.5 mm. A particularly simple design of the support surface is thus made possible, the degree of curvature of which can be adjusted substantially by changing the maximum height.In a further concretization, it is provided that the surface line has an S-shape corresponding to the spinal column curvature over the entire backrest. Preferably, a lordosis (hollow lumbar shape) is formed in the lumbar region by the S-shape and a kyphosis (back curvature) is formed in the thoracic region. In particular, the lumbar support formed in the lumbar region can be adjustable for adapting the curvature of the spinal column. A support surface is thus realized which is adapted to the anatomical shape of the human body, whereby the seating comfort is further improved.In a development, it is provided that the support surface in the cross section viewed in the vertical direction increasingly adapts to a radial plane of the seat direction in decreasing vertical direction. In other words, the support surface extends with decreasing vertical direction increasingly parallel and / or in the same direction as the transverse direction and / or to the radial plane. As shown in simplified form, the convex curvature of the support surface decreases counter to the vertical direction until the support surface continuously merges into the radial plane and / or the geometry of the lumbar vertebra region. Specifically, a height difference between the surface line and the side lines at least in the lumbar region is 0 mm. This ensures both a surface support of the upper back in the thoracic vertebra region and of the lower back in the lumbar vertebra region.In a further concretization, it is provided that the support surface is arranged in the vertical direction between a third and eleventh thoracic vertebrae, also referred to as Th 3 and Th 11, of a virtual dummy. In particular, the virtual dummy is to be understood as a three-dimensional simulation, e.g. a CAD model, of an adult person, which is placed virtually on a seat surface of the vehicle seat. The uppermost transverse line, which delimits the thoracic region in the vertical direction, is preferably assigned to the fourth thoracic vertebra and / or is arranged between the third and fourth thoracic vertebrae. In particular, a further, in particular a lowermost, transverse line is assigned to the tenth breast vertebra and / or is arranged between the tenth and eleventh breast vertebrae. The support surface is thus preferably clamped in the vertical direction between the two transverse lines and in the transverse direction between the two lateral lines. In particular, the uppermost transverse line has a maximum convex curvature and / or the lowermost transverse line has a minimum convex curvature. Alternatively, the lowermost transverse line extends in the radial plane of the seat direction.The invention further relates to a method for producing a backrest, as has already been described above, the geometry data of which are determined by the following method steps.In a first method step, a construction criterion defining the supporting surface is provided. The design criterion comprises a hip point, a torso axis extending from the hip point, and a surface auxiliary line and side auxiliary line delimiting the support surface in the transverse direction, wherein the surface auxiliary line and the side auxiliary line are connected via a plurality of transverse lines distributed in the vertical direction. In particular, the design criterion serves to project the support surface into any backrest base body and to generate a final backrest geometry therefrom. The design criterion preferably defines a basic shape of the support surface, which can be adapted or adapted to any desired backrest geometry by the subsequent method steps. In particular, the position and / or the surface shape and / or the width of the support surface can be adjusted by changing the corresponding parameters.In a second method step, the hip point is defined. In particular, the hip point can be assigned and / or assigned to the virtual dummy. Preferably, the hip point is set to match the hip joint of a dummy seated on the seat surface.In a third method step, a torso angle of the torso axis is defined. In particular, the torso axis can be assigned and / or assigned to the virtual dummy. Preferably, the torso axis defines an axis, in particular a z-axis, of a three-dimensional coordinate system, the origin of which is defined by the hip point. The torso angle corresponds to an angle formed between the torso axis and a perpendicular to the seat direction. The torso angle is preferably defined such that the torso axis coincides with a longitudinal central axis of the torso of a dummy seated on the seat surface.In a third method step, a seat-specific surface line is loaded, wherein the surface aid line is adapted to the seat-specific surface line while maintaining the side aid line. In particular, the surface auxiliary line corresponds to a rough or basic shape of the seat-specific surface line. The seat-specific surface line defines the final shape of the backrest base body to be constructed. Preferably, the surface auxiliary line is approximated to the seat-specific surface line within the scope of the adaptation and / or brought into overlap with the seat-specific surface line. Preferably, the surface aid line and the seat-specific surface line are identical after the adaptation.In a fourth method step, a distance in the transverse direction between the seat-specific surface line and the lateral auxiliary line is adjusted. Preferably, the surface auxiliary line is adapted here in the transverse direction to the seat-specific surface line and / or the side auxiliary line is adapted to a seat-specific side line.In a concreteization, it is provided that the distance and an orientation of the lateral auxiliary line and / or of the surface auxiliary line are adapted by changing a width of the lowermost and uppermost transverse line. In this case, the intermediate transverse lines can be aligned automatically or independently along the lateral auxiliary line connecting the lowermost and uppermost transverse lines. In particular, the distances for the lowermost and the uppermost transverse line are adapted in such a way that the seat-specific surface line or the surface auxiliary line are arranged in the transverse direction centrally of the backrest, in particular of the thoracic vertebra region and of the lumbar vertebra region, and / or that the seat-specific side line or the side auxiliary line are arranged laterally of the thoracic vertebra region, in particular of the stitching channel-if present. This ensures that the surface line and the side line are arranged correctly in position. In addition, the supporting surface spanned between the lateral auxiliary line and the surface line can be mirrored on the surface line to the other side in a simple manner.In a further concretization, within the scope of the adaptation, a curvature profile is determined for each of the transverse lines, which curvature profile, as viewed in the axial direction with respect to the vertical axis, has a convex curvature, the apex of which lies on the seat-specific surface line, wherein the convex curvature of the transverse lines following one another in the vertical direction increases. In particular, the uppermost transverse line has the greatest convexity and the lowermost transverse line has the smallest convexity or no convexity. In particular, the curvature profile is determined or adapted by changing and / or adapting the maximum height.In a further concretization, it is provided that the design criterion has a plurality of supporting beams distributed along the torso axis, which beams intersect the torso axis and the surface auxiliary line in a respective geometric supporting point, wherein the supporting points are adapted along the supporting beams to the seat-specific surface line. The supporting beams intersect the torso axis, preferably at right angles. Particularly preferably, a respective supporting beam and a respective transverse line intersect the surface auxiliary line in a respective supporting point. In other words, the apex of the associated transverse line is defined by a respective supporting point. Particularly preferably, the support points are displaced along the support beams, in particular onto the new support points or intersection points of the seat-specific transverse line. In particular, a respective supporting point and / or a respective transverse line can be and / or be positioned on a respective breast vertebra of the virtual dummy. This allows a particularly simple adaptation of the surface line to be realized.Further features, advantages and effects of the invention will become apparent from the following description of preferred exemplary embodiments of the invention. The following are shown: FIG. 1 shows a three-dimensional representation of a backrest for a vehicle seat; FIG. 2 shows a first sectional illustration A-A of the backrest, viewed in the vertical direction; FIG. 3 shows a second sectional illustration B-B of the backrest, viewed in the vertical direction; FIG. 4 shows a fourth sectional illustration C-C of the backrest, viewed in the vertical direction; FIG. 5 shows a first sectional illustration Y 0-Y 0 of the backrest viewed in the transverse direction; FIG. 6 shows a second sectional illustration D-D of the backrest viewed in the transverse direction; FIG. 7 shows a perspective illustration of a design criterion for determining geometry data for a supporting surface of the backrest from FIG. 1 ; FIG. 8 shows the construction criterion in the same illustration as shown in FIG. 7 with a seat-specific surface line; FIG. 9 shows a CAD model of the backrest with the support surface resulting from the design criterion.Corresponding or identical parts are each provided with the same reference numerals in the figures.FIG. 1 shows a backrest 1 for a vehicle seat, not shown, as an exemplary embodiment of the invention. The backrest 1 has a backrest base body 2 which is formed, for example, from backrest cushions produced from a foam material in one or more parts.The leek base body 2 has a lumbar region 3 and a thoracic region 4 adjoining the lumbar region 3 in the vertical direction HR. Furthermore, the leech base body 2 has a cervical vertebra region 5 adjoining the thoracic vertebra region 4 in the vertical direction HR and lateral cheek regions 6 adjoining both sides in the transverse direction QR at the lumbar vertebra region 3, the thoracic vertebra region 4 and the cervical vertebra region 5. The vertical direction HR and the transverse direction QR relate here to a Cartesian coordinate system, wherein the vertical direction HR is directed perpendicularly to a seat direction SR upwards and the transverse direction is directed perpendicularly to the seat direction SR.In the vertical direction HR, the thoracic vertebra region 4 is delimited by a transverse line 7 relative to the cervical vertebra region 5. In the transverse direction, the thoracic vertebra region 4 and the lumbar vertebra region 6 are each bounded by a side line 8 relative to the two side cheek regions 8. The transverse line 7 and the two side lines 8 can be understood in principle as imaginary lines, but in the exemplary embodiment shown these are defined by a circumferential stitching channel 5 for fastening a seat cover.Furthermore, the backrest 1 has a surface line 9 arranged centrally in the transverse direction QR, which surface line follows or defines the course of the surface of the backrest. In this case, the surface line 9 can be understood as a symmetry and / or center line of the backrest 1, in particular of the breast and lumbar vertebrae region 3, 4, which has an S shape corresponding substantially to the curvature of the spinal column.The thoracic vertebra region 4 has a support surface 10, by means of which a planar support of the upper back is achieved in that the support surface 10 has a curvature in the region of the surface line 9 that increases in the vertical direction HR or an increasing cavity in the region of the shoulder blades, whereby different support heights are achieved in the thoracic vertebra region 4 in the region of the upper back, which support heights are adapted to the anatomical shape of the human body. For describing the support surface 10, FIG. 1 shows a plurality of sections A-A, B-B, C-C, Y0-Y0, D-D, on the basis of which the support surface 10 is described below.FIGS. 2 to 4 show a detailed view of the sections A-A, B-B and C-C, which each form a cross section of the backrest 1 viewed in the vertical direction HR. As shown in FIG. 2, the support surface 10 has a convex curvature 11 which continuously decreases counter to the vertical direction HR, as shown in FIGS. 2 and 3, or increasingly forms on a radial plane 12 of the seat direction SR. The convex curvature 11 has an apex 13 which lies on the surface line 9, wherein the two curvature ends 14, only one shown here, lie on a side line 8 in each case. The convex curvature 11 thus extends over the entire width of the thoracic vertebra region 4 with a continuous or constant curvature profile. The convex curvature 11 increases steadily in the vertical direction HR up to the transverse line 7, as shown in FIG. 1, wherein a height 15 between the apex 13 and a connecting line 16 connecting the curvature ends 14 reaches its maximum at the location of the transverse line 7. For example, the maximum height 15 is at least or exactly 8 mm. The height 15 decreases steadily counter to the vertical direction HR, so that it has a minimum or is 0 mm at least in the case of a transition from the thoracic vertebra region 4 into the lumbar vertebra region 3. Shown in simplified form, the convex curvature 11 constantly decreases with decreasing vertical direction HR until it continuously merges into the geometry of the lumbar vertebra region 3.FIGS. 5 and 6 show a detailed view of the sections Y 0-Y 0 and D-D, which each form a cross section of the backrest 1 viewed in the transverse direction QR. As shown in FIG. 5, the surface line 9 within the thoracic vertebra region 4 has a curved and / or concave profile which increases from the transverse line 7 counter to the vertical direction HR in the seating direction SR. Due to the convex curvature 11 increasing in the vertical direction HR, as described in FIGS. 2 to 4, a resulting support surface 10 is obtained, the curvature profile of which increases with increasing transverse direction QR, as shown in FIG. 6. In other words, a cavity is increasingly formed in the transverse direction QR. The support surface 10 can extend in the vertical direction HR, for example, from the fourth thoracic vertebra (Th 4) to the tenth thoracic vertebra (Th 10) of a virtual dummy.In order to be able to introduce the required support surface 10 into the backrest base body 2, a method for determining the geometry data for the support surface 10 is described with reference to the following FIGS. 7 to 9.As shown in FIG. 7, a design criterion 17, in particular a CAD criterion, is provided within the scope of the method, with which it is possible to transfer the support surface 10 described in FIGS. 1 to 6 to any backrest base body 2 and to adapt it to its seat-specific surface. For this purpose, the design criterion 17 has a hip point HP and a torso axis TA running starting from the hip point HP, which torso axes can be assigned to a virtual dummy, not shown.Furthermore, the design criterion 17 has a surface auxiliary line 18 and a side auxiliary line 19 which delimit the supporting surface 10 in the transverse direction QR and which are connected to one another via a plurality of transverse lines 7 distributed in the vertical direction HR, wherein the supporting surface 10 is spanned between the surface auxiliary line 18 and the side auxiliary line 8, on the one hand, and between the transverse lines 7, on the other hand. In this case, the uppermost transverse line 7 corresponds to the transverse line 7 defined by the stitching channel 5, as described in FIG. 1, whereas a lowermost transverse line 7 is defined in such a way that the supporting surface 10 extends, starting from the uppermost transverse line 7, counter to the vertical direction HR, at least over more than 80% of the entire thoracic vertebra region 4 or completely over the entire thoracic vertebra region 4.The design criterion 17 has a plurality of supporting beams 20 distributed along the torso axis TA, which beams on the one hand intersect the torso axis TA at right angles and on the other hand intersect the surface auxiliary line 18 together with a respective transverse line 7 in a respective supporting point 21. For example, the transverse lines 7 or the supporting points 21 can each be positioned on a thoracic vertebra of the thoracic vertebra column of the virtual dummy, in particular between third and eleventh thoracic vertebrae (Th 3 to Th 11). In order to transfer the support surface 10 to a backrest 1 to be constructed, the method steps described below are carried out.In a first method step, hip point HP is defined in such a way that it corresponds on a hip joint of a virtual dummy, not shown, seated on the seat surface.In a second method step, a torso angle TW formed between the torso axis TA and a perpendicular is defined such that the torso axis TA coincides with a longitudinal central axis of a torso of the dummy seated on the seat surface, not shown.In a third method step, as shown in FIG. 8, a seat-specific surface line 9 is loaded, which defines an end shape of the backrest 1 to be constructed, wherein the surface auxiliary line 18 is adapted to the seat-specific surface line 9 while maintaining the side auxiliary line 8. For this purpose, the supporting points 21 can be displaced along the supporting beams 20 onto the points of intersection of the supporting beams 21 with the seat-specific surface line 9.In a fourth method step, as shown in FIG. 9, a distance 22 in the transverse direction QRof the lowermost and the uppermost transverse line 7 is adjusted such that the seat-specific surface line 9 is arranged in the middle of the thoracic vertebra region 4 in the transverse direction QRand / or the lateral auxiliary line 8 is adjusted to a seat-specific lateral line 8.Subsequently, the resulting support surface 10 is generated by determining for each of the transverse lines 7 a curvature profile which, viewed in the vertical direction HR or in the axial direction with respect to the torso axis TA, has the convex curvature 11, wherein the vertices 13 lie on the seat-specific surface line 9 and the convexity of the curvature 11 increases in the vertical direction HR. In other words, the vertices 13 are defined by the interpolation points 21. For example, the curvature can be changed by changing the height 15, in particular at the uppermost transverse line 7.While at least one embodiment has been disclosed in detail above, it should be appreciated that a variety of variations of the invention exist. It should also be appreciated that the at least one embodiment is exemplary only and is not a limitation on scope, areas of application, or configuration. Rather, the present disclosure is intended to be a pleasing travel plan for implementing at least one embodiment. Thus, it should be appreciated that various variations in the function or arrangement of the elements of the at least one embodiment may be implemented without departing from the scope specified by the claims and their legal equivalents.List of reference numbers:1 Backrest 2 Backrest base body 3 Lumbar vertebra region 4 Thoracic vertebra region 5 Cervical vertebra region 6 Side cheek region 7 Transverse line 8 Side line 9 Surface line 10 Support surface 11 Convex curvature 12 Radial plane 13 Apex 14 Curvature end 15 Height 16 Connecting line 17 Construction criterion 18 Surface auxiliary line 19 Side auxiliary line 20 Support beams 21 Support points 22 Distance HP Hip point HR Vertical direction QR Transverse direction SR Seat direction TA Torso axis TW Torso angleReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 1 351 839 B1

[0004]

Claims

Backrest (1) for a vehicle seat, - having a lehen base body (2) which has a lumbar vertebra region (3) and a breast vertebra region (4) adjoining the lumbar vertebra region (3) in the vertical direction (HR), - having a surface line (9) arranged in the transverse direction (QR) centrally of the lumbar vertebra region (3) and of the breast vertebra region (4), - having a transverse line (7) which delimits the breast vertebra region (4) in the vertical direction (HR), characterized in that a supporting surface (10) of the breast vertebra region (4) has an increasingly convex curvature (11) in a cross section, viewed in the vertical direction (HR), with increasing vertical direction (HR), the apex (13) of which lies on the surface line (9), wherein the surface line (9), viewed in the transverse direction (QR), has a curved and / or concave profile which increases in a seating direction (SR) starting from the transverse line (7) counter to the vertical direction (HR).Backrest (1) according to Claim 1, characterized by lateral lines (8) which delimit on both sides the lumbar region (3) and the thoracic region (4) in the transverse direction (QR), wherein the curved ends (14) of the convex curvature (11) lie on the lateral lines (8).Backrest (1) according to Claim 1 or 2, characterized in that a maximum height (15) between the apex (13) of the convex curvature (11) and a connecting line (16) connecting the curvature ends (14) of the convex curvature (11) is more than 4 mm and / or less than 12 mm.Backrest (1) according to one of the preceding claims, characterized in that the surface line (9) has an S shape corresponding to the curvature of the spinal column over the entire height of the backrest (1).Backrest (1) according to one of the preceding claims, characterized in that the support surface (10), in the cross section viewed in the vertical direction (HR), increasingly adapts to a radial plane (12) of the seat direction (SR) in the decreasing vertical direction (HR).Backrest (1) according to one of the preceding claims, characterized in that the supporting surface (10) is arranged in the vertical direction (HR) between a third and eleventh breast vertebra of a virtual dummy.Method for producing a backrest (1) according to one of the preceding claims, the geometry data of which are determined by the following steps: - providing a construction criterion (17) which defines the supporting surface (10) and comprises a hip point (HP), a torso axis (TA) running starting from the hip point (HP) and a surface auxiliary line (18) and side auxiliary line (19) which delimit the supporting surface (10) in the transverse direction (QR), wherein the surface auxiliary line (18) and the side auxiliary line (19) are connected via a plurality of transverse lines (7) distributed in the vertical direction (HR), - defining the hip point (HP), - defining a torso angle (TW) of the torso axis (TA), - loading a seat-specific surface line (18), wherein the surface auxiliary line (18) is adjusted to the seat-specific surface line (9) while maintaining the side auxiliary line (18). - a distance (22) in the transverse direction (QR) between the seat-specific surface line (9) and the side auxiliary line (19) is adjusted.Method according to claim 7, characterised in that the distance (22) and an orientation of the lateral auxiliary line (19) and / or of the surface auxiliary line (18) are adjusted by changing a width of the lowermost and uppermost transverse line (7).Method according to Claim 7 or 8, characterized in that a curvature profile is determined for each of the transverse lines (7), which curvature profile, as viewed in the vertical direction (HR), has a convex curvature (11), the apex (13) of which lies on the seat-specific surface line (9), wherein the convex curvature (11) of the transverse lines (7) following one another in the vertical direction (HR) becomes greater.Method according to one of Claims 7 to 9, characterized in that the design criterion (17) has a plurality of supporting beams (21) distributed along the torso axis (TA), which beams intersect the torso axis (TA) and the surface auxiliary line (18) in each case in a geometric supporting point (21), wherein the supporting points (21) are adapted to the seat-specific surface line (9) along the supporting beams (20).

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