vehicle seat

Abstract

The invention relates to a vehicle seat (1) comprising a seat part (6) and a vehicle seat base (2) with a lower part (4) and an upper part (5) that is height-adjustable relative to it, and at least one leaf spring (12) arranged between the upper part (5) and the lower part (4), wherein the leaf spring (12) has a first leg (12a) which is connected to the lower part (4) and a second leg (12b) arranged above it which is connected to the upper part (5), wherein a movable support element (13) is arranged between the first and the second leg, wherein the support element (13) rests on the first leg (12a) and the second leg (12b) rests on the support element (13), and the spring stiffness of the leaf spring (12) can be changed by moving the support element (13), wherein the leaf spring (12) has a first section (15a) in which the both legs (12a, 12b) are connected to each other,a second section (15b) in which both legs (12a, 12b) are parallel to each other, a third section (15c) in which both legs (12a, 12b) are concave to each other, and a fourth section (15d) in which both legs (12a, 12b) are at an angle (α) to each other.

Description

[0001] The invention relates to a vehicle seat comprising a seat part and a vehicle seat base with a lower part and an upper part which is height-adjustable to it, and at least one leaf spring arranged between the upper part and the lower part, wherein the leaf spring has a first leg which is connected to the lower part and has a second leg arranged above it which is connected to the upper part.

[0002] Occupants, especially drivers, of commercial vehicles such as vans, construction equipment, buses, tractors, etc., often spend many hours at a time in the vehicle seat, which is why seating comfort plays a crucial role in these types of vehicles. Particular emphasis is placed on absorbing and damping the vehicle's movements caused by road surfaces. Since the suspension of agricultural and construction machinery is often unable to compensate for uneven surfaces on unpaved terrain, or because the suspension characteristics can have adverse effects on the driver, these and other commercial vehicles are equipped with additional suspension systems in the seats. Furthermore, the driver's cabs in commercial vehicles are often very cramped due to additional control devices, making it necessary to design the seats accordingly.Many of these vehicle seat suspensions feature a swing arm in the form of a scissor-type frame, to which an air spring, coil spring, or conical spring is attached. The other part of the spring is attached to the lower part of the vehicle seat. Force from the occupant or the weight of the vehicle seat itself is transmitted to the suspension system only indirectly via the swing arm, which is why it must meet high demands and be correspondingly robust. Seats of this type are known, for example, from US Patent 4,093,197 A and EP 2,050,360 A1.

[0003] Therefore, the object of the invention is to provide a vehicle seat in which an improved suspension system reduces the space required, simplifies the design, and thus lowers assembly and costs. Additionally, the vehicle seat can be better adapted to the weight and size of an occupant.

[0004] To solve the problem, a vehicle seat according to the invention is provided, comprising a seat part and a vehicle seat base with a lower part and an upper part that is height-adjustable to it, and at least one leaf spring arranged between the upper part and the lower part, wherein the leaf spring has a first leg that is connected to the lower part and a second leg arranged above it that is connected to the upper part, wherein a movable support element is arranged between the first and second legs, wherein the support element rests on the first leg and the second leg rests on the support element, and wherein the spring stiffness of the leaf spring can be changed by moving the support element, wherein the leaf spring has a first section in which the two legs are connected to each other, and a second section in which both legs run parallel to each other.a third section in which both legs are concave towards each other and a fourth section in which both legs are at an angle α to each other.

[0005] A vehicle seat typically comprises a seat cushion on which the driver sits and a backrest against which the driver rests. Both the seat cushion and backrest are supported by the vehicle seat base. The vehicle seat may also have armrests attached to the seat cushion or backrest. The vehicle seat base usually consists of a rectangular, box-shaped, or plate-shaped upper section to which the seat and / or backrest are attached, and a rectangular, box-shaped, or plate-shaped lower section that is attached directly or indirectly to the vehicle body. "Directly" in this context can mean that the lower section is mounted on a slide or rail that engages with a corresponding track or slide, thus providing longitudinal adjustment of the vehicle seat.The upper part of the vehicle seat can be adjusted in height relative to the lower part by deforming the leaf spring in the vertical direction.

[0006] Preferably, the leaf spring is clamp-shaped and has a first leg and a second leg arranged opposite each other in the vertical direction. Preferably, the leaf spring is mirror-symmetrical, with the plane of symmetry being parallel to the plane formed by the width and length directions and located midway between the upper and lower portions. The legs can be ribbon-like, meaning that the legs are significantly wider and longer than they are thick. They are preferably extended in both the longitudinal and width directions. The leaf spring preferably has more than half the length, more preferably more than two-thirds the length, and most preferably more than three-quarters the length of the lower and / or upper portion.The leaf spring also preferably has more than half the width, more preferably more than two-thirds the width, and particularly preferably more than three-quarters the width of the lower portion and / or upper portion. Preferably, the leaf spring therefore largely covers the lower portion.

[0007] The longitudinal, lateral, and vertical directions describe a Cartesian coordinate system X, Y, Z that is oriented to the main extension directions of the vehicle seat. Thus, the seat section extends essentially in the longitudinal and lateral directions, whereas the back section extends essentially in the lateral and vertical directions.

[0008] In one embodiment, the leaf spring is connected at each end of the first leg and the second leg to the lower and upper portions, respectively. These end regions are positioned opposite the section of the leaf spring where the first and second legs are connected. The end regions are located as far away as possible from the section where the two legs are joined. This maximizes the length of the spring and thus the suspension travel of the vehicle seat.

[0009] A movable support element is arranged between the legs of the leaf spring, such that the leaf spring at least partially encloses the support element. The support element is preferably designed as a cylindrical roller. Alternatively, the support element can also be cuboid or, more generally, prismatic. Preferably, the support element is essentially as wide as the leaf spring, and particularly preferably wider than the leaf spring, in the area where the support element is arranged between the leaf spring. The support element rests on the first, lower leg, which runs at least partially parallel to the longitudinal and lateral directions. The second leg rests on the support element. The bearing points on which the support element and the second leg are placed are preferably arranged directly above one another in the vertical direction.

[0010] According to a particularly preferred embodiment, the support element is displaceable in a direction perpendicular to a spring direction of the leaf spring, wherein the direction is parallel to a principal extension direction of the leaf spring.

[0011] By shifting the support element, the contact points of the support element, or rather of the second leg, can be moved along the longitudinal direction. The position of the support element and the contact points determines the lever arm of the leaf spring. The further the support element is shifted towards the ends, the shorter the lever arm of the leaf spring. The further the support element is from the ends, the longer the lever arm. The spring constant of the leaf spring depends on the length of the lever arm, which can be changed by moving the support element.

[0012] According to a particularly preferred embodiment, the leaf spring is a one- or multi-part curved leaf spring, wherein the leaf spring is at least partially U- and / or V-shaped in profile.

[0013] According to the invention, the leaf spring has a first section in which the two legs are connected to each other, a second section in which both legs run parallel to each other, a third section in which both legs run concave to each other, and a fourth section in which both legs run at an angle α to each other.

[0014] Preferably, the first and second sections form a U-shaped part of the leaf spring. The third section forms the transition from the second to the fourth section, in which the legs diverge in a V-shape at an angle α. The V-shaped portion, or the section in which the leaf spring diverges at an angle α, allows the required leaf spring height for effective suspension to be achieved. Preferably, the leaf spring is taller than 80 mm when uncompressed, more preferably taller than 100 mm, and particularly preferably taller than 120 mm. However, according to one embodiment, the leaf spring height is less than 180 mm, and more preferably less than 160 mm. The support element is arranged in the U-shaped portion, or in the second and partially also the third section. This portion, or these sections, thus serve to support the support element.

[0015] According to a particularly preferred embodiment, the first leg has a first recess in the fourth section, the leaf spring has a second recess in the first section, and the second leg has a third recess in the fourth section, wherein the recesses reduce the spring stiffness of the leaf spring and split the leaf spring in the corresponding sections along a width direction into two part sections.

[0016] These recesses serve multiple purposes simultaneously. First, they reduce the weight and material requirements of the leaf spring. Furthermore, the recesses modify the spring rate of the leaf spring. The spring rate can therefore be adjusted for different spring travels. In particular, the second recess can extend into the second section. Depending on the position of the support element relative to the recess, the spring-rate-reducing effect of the recess can be fully, partially, or not at all noticeable. Additionally, the recesses can also allow for the attachment of further components, as described below.

[0017] According to a particularly preferred embodiment, the support element can be moved between a maximum position and a minimum position via an adjustment device and can be locked in at least two positions.

[0018] Adjusting and locking the support element therefore necessitates adjusting and locking the spring stiffness. The leaf spring exhibits different spring characteristics for different positions of the support element.

[0019] According to a particularly preferred embodiment, the minimum position is located at the transition from the first section to the second section and the maximum position is located within the third section, wherein the adjustable spring stiffness is minimal for the minimum position and maximum for the maximum position.

[0020] According to a particularly preferred embodiment, the spring rate and / or the preload of the leaf spring can be changed by means of the support element.

[0021] The spring rate of the leaf spring determines, in particular, how comfortable the suspension of the vehicle seat is for an occupant. Especially because the suspension of heavy vehicles inherently exhibits an unfavorable oscillation frequency, additional suspension of the vehicle seat is necessary. A value of 1 Hz to 1.5 Hz has been established as the preferred spring rate. The spring rate, in turn, is determined by the sprung mass and the spring stiffness. f=12πkm. Since the vehicle seat according to the invention is intended to be adjustable to the weight of an occupant, ranging from 50 kg to 150 kg, the desired spring stiffness values ​​range from greater than 2000 N / m to less than 15000 N / m. Because the weight of the seat and backrest sections, as well as additional components such as armrests or control consoles, varies for different versions, the spring stiffness values ​​can also fluctuate by up to +1500 N / m. Advantageously, the preload of the spring element, or its height, can be changed simultaneously by altering the spring stiffness of the leaf spring. Since the weight of the seat, backrest, etc., already exerts a force on the leaf spring even without an occupant, the leaf spring is compressed, or preloaded. Depending on how stiff or soft the leaf spring is set by the support element, the leaf spring will deform more or less under the weight of the seat, backrest, etc., which is noticeable in a smaller or larger spring compression and thus a lower or greater seat height.

[0022] According to a particularly preferred embodiment, the adjusting device has a linear drive with a threaded spindle, wherein the adjusting device is not connected to the lower part or the upper part.

[0023] To enable the support element to be moved within the leaf spring, preferably longitudinally, the adjusting device has a linear drive with a threaded spindle. This spindle can be guided longitudinally through the second recess. In one embodiment, a counter-holding element is arranged on the leaf spring, against which the threaded spindle is supported relative to the leaf spring. For example, the counter-holding element can have a thread suitable for the threaded spindle. By rotating the threaded spindle in the thread, the spindle is moved longitudinally. The threaded spindle is rotatably mounted on the support element, which can be moved longitudinally by rotating the threaded spindle. Advantageously, the adjusting device is not connected to the lower or upper portion of the support element.

[0024] Because the adjusting mechanism is not connected to either the lower or upper part, the transmission of forces from either part to the leaf spring is prevented. Furthermore, complete locking of the support element relative to the leaf spring can be achieved.

[0025] According to a particularly preferred embodiment, the adjusting device has a linear drive which is arranged on the lower or upper part, wherein the support element is connected to the linear drive via at least one coupling element in a thrust and tension-transmitting manner.

[0026] A disadvantage of arranging the adjustment mechanism on the leaf spring is that the adjustment element is typically located between the upper and lower sections, making it more difficult for smaller occupants to reach. Therefore, it is advantageous to position the adjustment mechanism on the upper section. In this case, the linear actuator can be connected to a coupling element to transmit both thrust and tension. Suitable linear actuators include electrical or mechanical systems, such as a rack and pinion or a lead screw. However, a disadvantage here is that the height adjustment of the upper relative to the lower section by the coupling element can negatively affect the position of the support element. This height adjustment can unintentionally affect the spring stiffness by shifting the support element through the coupling element.

[0027] Further advantageous embodiments are described in the dependent claims and the following description in conjunction with the drawing. These show: Fig. 1 a general view of a vehicle seat according to the invention; Fig. 2 a section through a vehicle seat according to the invention in a fully extended position; Fig. 3 a leaf spring according to the invention; Fig. 4 a section of the vehicle seat base in side view;

[0028] For the sake of clarity, some reference symbols have been omitted from the figures.

[0029] The Fig. Figure 1 shows a vehicle seat 1 according to the invention. The vehicle seat 1 extends upwards and downwards in a vertical direction Z, forwards and backwards in a longitudinal direction X, and to the right and left in a lateral direction Y. In a lower area, the vehicle seat comprises a vehicle seat base 2. The vehicle seat base 2 forms the connection between the vehicle seat structure 3 and a vehicle and is designed to perform a spring movement. A lower portion 4 of the vehicle seat base 2 is screwed to the vehicle body. The lower portion 4 is connected to an upper portion 5 above it via a connecting element 11 (not shown) and a leaf spring 12 (also not shown). The upper portion 5 supports the vehicle seat structure 3. This initially comprises a seat part 6, which is attached to the upper portion 5 by means of an adjustment rail 10.The adjustment rail 10 allows the vehicle seat assembly 3 to be moved longitudinally in the X direction. Alternatively, the adjustment rail 10 can also be arranged between the lower part 4 and the vehicle body, so that the entire vehicle seat 1 is movable. A backrest 7 is also attached to the seat section 6, extending primarily in the width direction Y and the height direction Z. Armrests 9 are arranged on both sides of the backrest 7, and a headrest 8 is located in an upper area of ​​the backrest 7.

[0030] The Fig. Figure 2 shows a section through a vehicle seat 1 according to the invention along an XZ plane. The seat section 6 and the backrest 7 are arranged on the vehicle seat base 2. The vehicle seat base 2 comprises the lower section 4, the upper section 5, the connecting element 11 arranged between them, and the leaf spring 12. The connecting element 11 is arranged in a front region between the upper section 5 and the lower section 4, whereas the leaf spring extends from the front region to a rear end region of sections 4 and 5. The leaf spring is connected to the lower section 4 via a first leg 12a and to the upper section 5 via a second leg 12b.A force, for example from an occupant sitting on the seat or simply from the weight of the vehicle seat structure 3, is transmitted directly from the upper portion 5 into the leaf spring 12 and from there into the lower portion 4, without being significantly transferred to the connecting component. This means that the connecting component 11 bears considerably less load than the leaf spring 12 and can therefore be made primarily of plastic, for example, POM. The leaf spring 12 is usually made of spring steel.

[0031] The leaf spring 12 extends longitudinally over more than three-quarters of the length of the upper portion 5 and the lower portion 4, respectively. The connecting element 11, located at the front end of the leaf spring 12 where the two legs 12a and 12b are joined, stabilizes the upper portion 5 relative to the lower portion 4, thus preventing the upper portion 5 from tilting relative to the lower portion 4. The connecting element 11 therefore has a supporting, not a load-bearing, role. Consequently, the lower portion 4 and the upper portion 5 remain essentially parallel to each other during height adjustment. The leaf spring 12 also encloses a cylindrical support element 13 on its upper and lower sides. The support element 13 is displaceable along the longitudinal direction X of the leaf spring 12.The path from the support element 13 to a mounting point 14, where the legs are attached to the upper portion 5 and the lower portion 4 respectively, is defined as the lever arm 12c of the leaf spring 12. Specifically, the lever arms 12c for the two legs 12a and 12b of the leaf spring 12 are equal. During height adjustment, increased tensile and compressive stresses and deformations occur in the leaf spring 12, particularly in the area of ​​the support element 13. Therefore, the movement of the support element 13 can subject different areas of the leaf spring 12 to stress during height adjustment or spring movement of the upper portion 5 to the lower portion 4.

[0032] The connecting component 11 comprises a scissor frame with a first arm and a second arm that intersect and are both rotatably arranged about a common axis of rotation. The ends of the scissor arms are connected to the upper portion 5 and the lower portion 4 via sliding bearings. The ends are guided in grooves by means of sliders, with at least one groove in the upper portion 5 and at least one groove in the lower portion 4 for each scissor arm.

[0033] A damper 19 is arranged in the rear section between the upper part 5 and the lower part 4. The damper 19 connects the upper part 5 to the lower part 4 and dampens an oscillating movement from the upper part 5 to the lower part 4. So that the damper 19 functions as described in Fig. As shown in Figure 2, the two legs 12a and 12b of the leaf spring each have a recess 16a and 16c through which the damper 19 passes. This allows the damper 19 to be advantageously connected directly to the upper portion 5 and the lower portion 4, thus directly damping the movement between the upper portion 5 and the lower portion 4. In contrast, many other vehicle seats typically arrange the spring and / or damper between the connecting component 11 and the upper portion 5 or the lower portion 4. In this case, spring movement is only transmitted indirectly via the connecting component 11, which negatively affects the suspension characteristics of the vehicle seat.

[0034] The Fig. Figure 3 shows a leaf spring 12 according to one embodiment of the invention. The leaf spring 12 is divided into four sections 15a to 15d. The first section 15a is semicircular in the XZ direction and forms the connection between the two legs 12a and 12b. As an alternative to the one-piece design of the leaf spring 12, it can also consist of two or more parts. In particular, it is conceivable that the first and second legs 12a and 12b are positively and / or force-fit connected to each other in the first section. For example, a screw connection is conceivable, by means of which the spring stiffness of the leaf spring 12 can also be adjusted. In the longitudinal direction, the first section 15a forms one end of the leaf spring and then transitions into the subsequent second section 15b.In this section, the first leg 12a and the second leg 12b run parallel to each other, meaning that the two legs 12a and 12b are equidistant in the vertical direction Z. The second section 15b sometimes forms a channel in which the support element can slide along the longitudinal direction X. In the subsequent third section 15c, the first leg 12a and the second leg 12b curve concavely, i.e., away from each other, with the distance between them increasing and the leaf spring beginning to widen. In the fourth section 15d, the first leg 12a and the second leg 12b each run straight and at an angle α of 40° to each other. While the first and second sections 15a and 15b in particular form a U-shaped part of the leaf spring 12, the third section 15c and in particular the fourth section 15d form a V-shaped part of the leaf spring 12.The first section 15a and the second section 15b correspond to approximately one-third of the length of the leaf spring 12 in longitudinal direction X. The third and fourth sections also each correspond to approximately one-third of the length of the leaf spring 12.

[0035] Several recesses 16a to 16c are provided in the leaf spring 12. A first recess 16a is made as a longitudinal incision X, starting from the end of the first leg 12a. This extends over the fourth section 15d and partially into the third section 15c. Symmetrically to this, the third recess 16c is made as a incision in the second leg 12b. The legs 12a and 12b are thus partially split in two. With reference to Fig. 2. Within the first recess 16a and the third recess 16c, a damper is arranged, connecting the upper portion 5 with the lower portion 4. Furthermore, a second recess 16b is arranged longitudinally X opposite the first recess 16a and the third recess 16c. This second recess also extends as a cut in the longitudinal direction X. While the first recess 16a and the third recess 16c taper conically towards the center of the leaf spring 12 in the longitudinal direction X, the cut edges of the second recess 16b run at least partially parallel in the longitudinal direction X. The ends of the recesses 16a to 16c are rounded. The recesses 16a to 16c reduce, in particular, the spring stiffness of the leaf spring 12, the material requirements, and allow the attachment of a damper 19 and / or an adjusting device 17.

[0036] At the ends of the two legs (12a, 12b) are recesses in the form of bores 18. These bores 18 serve to fasten the leaf spring 12 to the upper portion 5 and the lower portion 4. For example, the leaf spring can be directly connected to the upper portion 5 and / or the lower portion 4 via a screw connection. Alternatively, the leaf spring can also be connected to the upper portion 5 and / or the lower portion 4 via a bearing bushing. The leaf spring 12 can therefore be rotatably connected to the upper portion 5 about a first axis of rotation and rotatably connected to the lower portion 4 about a second axis of rotation.

[0037] The Fig. Figure 4 shows a section of the vehicle seat base 2 in a side view. The leaf spring 12 is positioned centrally between the upper portion 5 and the lower portion 4. In an indicated minimum position 13a, the support element 13 is positioned as close as possible to the first section 15a. In particular, the support element 13 has essentially the same radius as the semicircular first section 15a. In the indicated minimum position 13a, the support element 13 connects directly to the first section 15a. In the maximum position 13b, the support element 13 is shifted to or into the third section 15c, in which the first leg 12a and the second leg 12b diverge concavely. An adjustment device 17 is attached to the support element 13, allowing it to be continuously shifted between the minimum position 13a and the maximum position 13b.The support element 13 can be locked in any position between the minimum position 13a and the maximum position 13b. Depending on the position of the support element 13, the length of the lever arm 12c, i.e., the length between the support element and a mounting point 14 between one leg and one of the two parts, is changed. If the support element 13 is closer to the minimum position 13a, then the length of the lever arms 12c is greater. In simplified terms, this means that a greater torque acts on the contact points of the support element 13 and the first leg 12a, as well as between the support element 13 and the second leg 12b. This greater torque leads to easier deformation of the leaf spring 12 at the contact points, making the leaf spring 12 softer. Conversely, if the support element 13 is closer to the maximum position 13b, the lever arm 12 of the legs becomes shorter, and thus the spring becomes stiffer.

[0038] The adjusting device 17 comprises a threaded spindle 17a, which is arranged parallel to the upper portion 5 and the lower portion 4, centrally located between them in the vertical direction. Furthermore, the threaded spindle 17a extends through the second recess 16b. This means that the threaded spindle 17a is located partially inside and partially outside the leaf spring 12. "Inside" in this context means that the threaded spindle 17a is enclosed on at least two sides by the first leg 12a and the second leg 12b. A threaded bearing 17d is fixedly connected to the leaf spring 12 at the first section 15a. The threaded bearing 17d allows the threaded spindle 17a to rotate about its longitudinal axis, but prevents it from shifting relative to the first section 15a.At one front end of the threaded spindle 17a, facing the front of the vehicle seat, a rotary knob 17c is arranged, which allows the threaded spindle 17a to be rotated about its longitudinal axis. Opposite this, beyond the threaded bearing 17d, i.e., inside the leaf spring 12, a guide nut 17b is arranged, which has an internal thread into which a corresponding external thread of the threaded spindle 17a engages. Since the threaded spindle 17a is fixedly mounted, i.e., immovably, relative to the leaf spring 12, a rotation of the threaded spindle 17a causes the guide nut 17b to move within the leaf spring 12. The support element 13 is attached to the guide nut 17b, so that the support element 13 can be moved back and forth between the maximum position 13b and the minimum position 13a by turning the rotary knob 17c. By turning the rotary knob 17c, the spring stiffness and / or the spring frequency of the leaf spring can be changed.At the end of the threaded spindle 17a, a stop is also arranged which prevents the guide nut 17b from slipping off the threaded spindle 17a.

[0039] In the vertical direction Z, the leaf spring 12 has a stroke of 80 mm. The support element 13 can be displaced longitudinally by 120 mm. Since the leaf spring 12 is designed for an occupant weight of 50 to 150 kg, the 120 mm displacement corresponds to a change in spring stiffness of approximately 12,000 N / m. The leaf spring 12 is pre-tensioned by 70 mm compared to an uncompressed state.

[0040] The Fig.Figure 5 shows an alternative embodiment of a vehicle seat 1 according to the invention. The vehicle seat 1 has a box-shaped lower section 4 and a box-shaped upper section 5 arranged parallel to and above it, which supports the seat section 6 and the backrest 7. The two sections are connected to each other via a connecting element 11 in the form of a scissor mechanism. Both sections are connected so as to be slidable relative to each other in the vertical direction Z. In addition, a leaf spring 12 with a first leg 12a and a second leg 12b is connected between the upper section 5 and the lower section 4. A support element 13 is arranged inside the leaf spring, which can be moved between a maximum position 13b for maximum spring stiffness and a minimum position 13a for minimum spring stiffness by means of an adjusting device 17. For this purpose, the adjusting device 17 comprises a linear drive with a threaded spindle 17a and a guide nut 17b.The scissor frame 11 comprises a first scissor arm 11a and a second scissor arm 11b, which are connected to each other about a pivot axis 11c. Each of the two scissor arms is connected to one of the sections via a floating bearing 11e and to the other section via a fixed bearing 11d. A damper 19 is also connected to the fixed bearing 11d of the upper section 5 and to the lower section via another fixed bearing. Reference symbol list 1 vehicle seat 2 Vehicle seat base 3 Vehicle seat structure 4 lower part 5 upper part 6 Seat section 7 Back section 8 Headrest 9 Armrest 10 Adjustment rail 11 Connecting component 11a first scissor arm 11b second scissor arm 11c axis of rotation 11d Fixed Camp 11e Lotlager 12 leaf spring 12a first leg 12b second thigh 12c lever arm 13 Support element 13a Minimum position of the support element 13b Maximum position of the support element 14 Mounting point 15a first section 15b second section 15c third section 15d fourth section 16a first exemption 16b second exemption 16c third exemption 17 Adjustment device 17a Threaded spindle 17b Lead Mother 17c rotary knob 17d threaded bearing 18 bore 19 dampers X Vehicle seat longitudinal direction Y Vehicle seat width direction Z Vehicle seat height direction α Angle between first and second leg

Claims

[1] Vehicle seat (1) comprising a seat part (6) and a vehicle seat base (2) with a lower part (4) and an upper part (5) which is height-adjustable thereto and at least one leaf spring (12) arranged between the upper part (5) and the lower part (4), wherein the leaf spring (12) has a first leg (12a) which is connected to the lower part (4) and has a second leg (12b) arranged above it which is connected to the upper part (5), characterized by, that a movable support element (13) is arranged between the first and the second leg (12a, 12b), wherein the support element (13) rests on the first leg (12a) and the second leg (12b) rests on the support element (13), and the spring stiffness of the leaf spring (12) can be changed by moving the support element (13), wherein the leaf spring (12) has a first section (15a) in which the two legs (12a, 12b) are connected to each other, a second section (15b) in which both legs (12a, 12b) are parallel to each other, a third section (15c) in which both legs (12a, 12b) are concave to each other, and a fourth section (15d) in which both legs (12a, 12b) are at an angle (α) run towards each other. [2] Vehicle seat (1) according to claim 1, characterized by, that the support element (13) is displaceable in a direction perpendicular to a suspension direction of the leaf spring (12), wherein the direction is parallel to a principal extension direction of the leaf spring (12). [3] Vehicle seat (1) according to any of the preceding claims, characterized by , that the leaf spring (12) is a one- or multi-part curved leaf spring (12), wherein the leaf spring (12) is at least partially U- and / or V-shaped in profile. [4] Vehicle seat (1) according to claim 1, characterized by, that the first leg (12a) in the fourth section (15d) has a first recess (16a), the leaf spring (12) in the first section (15a) has a second recess (16b) and the second leg (12b) in the fourth section (15d) has a third recess (16c), wherein the recesses (16a, 16b, 16c) reduce the spring stiffness of the leaf spring (12) and split the leaf spring (12) in the corresponding sections (15a, 15d) along a lateral direction Y into two part sections. [5] Vehicle seat (1) according to claim 1, characterized by that the support element (13) is movable between a maximum position (13b) and a minimum position (13a) via an adjustment device (17) and can be locked in at least two positions. [6] Vehicle seat (1) according to claim 1 and 5, characterized by, that the minimum position (13a) is located at the transition from the first section (15a) to the second section (15b) and the maximum position (13b) is located within the third section (15c), wherein the adjustable spring stiffness is minimal for the minimum position (13a) and maximum for the maximum position (13b). [7] Vehicle seat (1) according to claim 5, characterized by , that the spring rate and / or the preload of the leaf spring (12) can be changed by means of the support element (13). [8] Vehicle seat (1) according to claims 4 and 5, characterized by that the adjusting device (17) has a linear drive with a threaded spindle, wherein the adjusting device (17) is not connected to the lower part (4) or the upper part (5). [9] Vehicle seat (1) according to claim 5, characterized by, that the adjusting device (17) has a linear drive which is arranged on the lower or upper part (4, 5), wherein the support element (13) is connected to the linear drive via at least one coupling element in a thrust and tension-transmitting manner.

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