Lumbar support for a seat

Abstract

Lumbar support (100) for a seat (200) defining a back plane (E), comprising: a support device (10) comprising an upper end (O) enclosing an upper angle of inclination (α) with the back plane (E) and a lower end (U) enclosing a lower angle of inclination (β) with the back plane (E) and forming a crown (S) which is in an adjustable position between the upper end (O) and the lower end (U); at least one angle adjuster (20, 25) connected to the upper end (O) or the lower end (U) of the support device (10) and suitable for changing the upper tilt angle (α) or the lower tilt angle (β) in order to adjust the position of the crown (S), and an actuator (30, 35) for adjusting the angle adjuster (20, 25); characterized by a bearing element (55) for the angle adjuster (20, 25) and by a coupling (65) which has a first end (65a) and a second end (65b); wherein the angle adjuster (20, 25) has a clamping element (60) comprising a connecting section (61) and a coupling point (63); wherein the connecting section (61) is rotatably and slidably mounted on the bearing element (55); wherein the first end (65a) of the coupling (65) is rotatably connected to the clamping element (60) at the coupling point (63) and the second end (65b) of the coupling (65) is rotatably connected to the bearing element (55) and wherein the actuator (30, 35) engages the connecting section (61) to cause a movement of the clamping element (60) relative to the bearing element (55) by which the upper inclination angle (α) or the lower inclination angle (β) is changed.

Description

[0001] The invention relates to a lumbar support for a seat, in particular for a motor vehicle seat. Furthermore, the invention relates to a seat comprising the lumbar support.

[0002] Lordosis generally refers to a forward curvature of the spine, i.e., toward the abdomen. The spine of healthy people exhibits lordosis in the cervical spine and lordosis in the lumbar spine. When sitting, the lumbar spine, in particular, bears a high load. Lumbar supports are used to support lordosis in the lumbar spine. Appropriate support of lordosis in the lumbar spine relieves strain on the muscles. This allows for relaxed and comfortable sitting, even for extended periods.

[0003] Lumbar supports are typically installed in the backrest of seats behind the cushion. Each person's back contour is unique and differs depending on their fitness level, physiological, and psychological state. Furthermore, each person perceives lumbar support differently. It is therefore advantageous if the lumbar support is adjustable to meet these individual needs. A distinction is made between two-way lumbar supports, where only the curvature is adjustable, and four-way lumbar supports, where both the curvature and the height of the arch are adjustable.

[0004] Various concepts are known for adjusting lumbar support. Lumbar supports are often adjusted electromechanically or pneumatically. For example, an electromechanical four-way lumbar support requires an actuator to adjust the curvature and another actuator to adjust the height of the crown of the arch. The actuator for the height adjustment must cover comparatively large distances of up to 100 mm. Alternatively, a single actuator with a gear can be installed, as disclosed in DE 10 2014 201 049 A1. In a pneumatic four-way lumbar support, a compressor fills several air cells. Several valves open and close the air cells.

[0005] AT 358 767 B discloses a flexible, elastic support whose ends can be tilted by means of hinges to offset a curvature of the support. The hinges are adjustable by means of a screw spindle.

[0006] A backrest for a wheelchair is disclosed in US 2008 / 0079298 A1. The backrest is connected to a frame, which allows the shape of the backrest to be adjusted. Further prior art is shown in the publications US 020110121624 A1, US 020050275263 A1, EP 000000312506 A1, US 020160325661 A1, US 000004880271 A, DE 000003324655 A1, and DE 102004012850 A1.

[0007] The invention is based on the object of creating a lumbar support that is continuously adjustable with small actuator travels.

[0008] The object is achieved by a lumbar support according to claim 1 and by a seat according to claim 12. Advantageous embodiments of the lumbar support are the subject of claims 2 to 11.

[0009] The lumbar support according to the invention for a seat defining a back plane comprises a support device having an upper end that includes an upper angle of inclination with the back plane and a lower end that includes a lower angle of inclination with the back plane, and forming a crown located in an adjustable position between the upper end and the lower end, at least one angle adjuster connected to the upper end or the lower end and adapted to change the upper angle of inclination or the lower angle of inclination in order to adjust the position of the crown of the crown, an actuator for adjusting the angle adjuster, a bearing element for the angle adjuster, and a coupling having a first end and a second end, wherein the angle adjuster has a clamping element comprising a connecting portion and a coupling point,wherein the connecting portion is rotatably and displaceably mounted on the bearing element, wherein the first end of the coupling is rotatably connected to the clamping element at the coupling point and the second end of the coupling is rotatably connected to the bearing element, and wherein the actuator acts on the connecting portion to cause a movement of the clamping element relative to the bearing element, by which the upper inclination angle or the lower inclination angle is changed.

[0010] The apex of the arch is the apex of the support device, i.e., the point of the support device that, when installed, is the greatest distance from the back plane in a longitudinal direction of the seat. The position of the apex of the arch has a longitudinal component relative to the back plane in a direction perpendicular to the back plane and a height component relative to a reference plane that runs through a seat surface of the seat and parallel to the back plane.

[0011] When changing the upper and / or lower tilt angle, the support device's shape changes, allowing the position of the arch's crown to be adjusted vertically and / or longitudinally. Adjusting the position of the arch's crown using the angle adjuster(s) requires only small actuator travel. The lumbar support is continuously adjustable.

[0012] By activating the actuator, the connecting section of the clamping element is moved along the bearing element. The coupling also causes the clamping element to tilt. The upper or lower tilt angle is changed by adjusting the inclination of the clamping element.

[0013] The lumbar support advantageously features an upper angle adjuster connected to the upper end and a lower angle adjuster connected to the lower end. This creates a four-way lumbar support with adjustable curvature and height.

[0014] In an advantageous embodiment, the support device is clamped into the angle adjuster at the upper end and / or the lower end in a rotationally fixed manner. This ensures that a change in the upper and / or lower angle of inclination causes a change in the curvature of the support device, thus adjusting the position of the apex of the curvature.

[0015] The support device advantageously comprises a lumbar mat featuring a plurality of interconnected mat elements. This allows the support device to assume a shape that is particularly well adapted to the spine, providing optimal support for the lumbar spine.

[0016] In order to be able to adapt the shape of the support device to the spine, the mat elements advantageously have an extension axis that runs essentially parallel to the plane of the back.

[0017] The actuator allows for convenient adjustment of the position of the arch and can advantageously be designed as a shape memory actuator. Shape memory actuators have the advantages of being comparatively light, quiet, and energy-efficient. Shape memory actuators are particularly suitable for use in lumbar support because they apply large forces with only small adjustment ranges.

[0018] In an advantageous embodiment, the actuator can be provided with a displaceably mounted floating bearing connected to the connecting section. Preferably, the clamping element has a bolt that is attached to the floating bearing to transmit a displacement of the floating bearing to the clamping element.

[0019] The lumbar support advantageously includes a locking device for locking the angle adjuster. The angle adjuster can then be locked when the apex of the lumbar spine is in the desired position. This ensures that the angle adjuster always remains in its setting, even when the actuator is not energized.

[0020] In an advantageous embodiment, the locking device can have a wrap spring and a wrap spring drive, wherein the wrap spring drive is designed to transfer the wrap spring from a relaxed state in which the wrap spring locks the angle adjuster into a tensioned state in which the wrap spring releases the angle adjuster.

[0021] In an advantageous embodiment, the lumbar support includes a mounting plate to which the angle adjuster is mounted by the bearing element. This results in a functional and practical connection between the angle adjuster and the seat.

[0022] The seat according to the invention is in particular a motor vehicle seat which has the lumbar support.

[0023] The invention is described below with reference to schematic drawings based on exemplary embodiments. The drawings show: Fig. 1 a perspective view of a vehicle seat; Fig. 2 a perspective view of a first embodiment of the lumbar support according to the invention; Fig. 3a is a side view of a second embodiment of the lumbar support according to the invention, in which the upper angle of inclination and the lower angle of inclination are minimized; Fig. 3b a side view of the embodiment according to Fig. 3a, where the lower inclination angle is maximized; Fig. 3c a side view of the embodiment according to Fig. 3a, in which the lower inclination angle and the upper inclination angle are increased; Fig. 3d a side view of the embodiment according to Fig. 3a, where the upper inclination angle is maximized; Fig. 4a an enlarged view of the lower angle adjuster according to detail IVa in Fig. 3a; Fig. 4b an enlarged view of the lower angle adjuster according to detail IVb in Fig. 3b; Fig. 4c an enlarged view of the lower angle adjuster according to detail IVc in Fig. 3c; Fig. 4d an enlarged view of the lower angle adjuster according to detail IVd in Fig. 3d and Fig. 5 a section through a locking device.

[0024] Fig. Figure 1 shows a seat 200 as installed in a motor vehicle. The seat 200 has a backrest 201 and a seat surface 202 and defines a back plane E. A Fig. 1 lumbar support (not shown) is installed in the backrest 201 and supports the lordosis in the lumbar spine area.

[0025] A lumbar support 100 for the seat 200 clearly shows Fig. 2. The lumbar support 100 comprises a support device 10, an upper angle adjuster 20, and a lower angle adjuster 25. The support device 10 has an upper end O and a lower end U. The upper angle adjuster 20 is connected to the upper end O. The lower angle adjuster 25 is connected to the lower end U. Conveniently, the support device 10 is clamped at the upper end O in a rotationally fixed manner into the upper angle adjuster 20 and at the lower end U in a rotationally fixed manner into the lower angle adjuster 25.

[0026] The support device 10 further comprises a lumbar support mat 11. The lumbar support mat 11 is provided with a plurality of mat elements 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, which are hingedly connected to one another and each have an extension axis A, which is shown only as an example for the mat element 12e. The extension axis A runs essentially parallel to the back plane E.

[0027] How Fig. As clearly shown in Figures 3a to 3d, the upper end O of the support device 10 forms an upper angle of inclination α with the back plane E. The lower end U of the support device 10 forms a lower angle of inclination β with the back plane E. The support device 10 forms a vault apex S which is located in an adjustable position between the upper end O and the lower end U. The angle adjusters 20, 25 serve to change the upper angle of inclination α or the lower angle of inclination β in order to adjust the position of the vault apex S.

[0028] The arch apex S is the apex of the support device 10. The arch apex S is thus the point of the support device 10 which has the greatest distance to the back plane E. As in Fig. As is clearly shown in Figure 1, the position of the crown S has a longitudinal component S Lwith respect to the back plane E in a direction perpendicular to the back plane E and a height component S H with respect to a reference plane B, which runs through the seat surface 202 and parallel to the back plane E. When changing the upper angle of inclination α and / or the lower angle of inclination β, the support device 10 is changed in its shape, so that the position of the arch apex S in the height component S H and / or in the longitudinal component S L is adjusted. Thus, the shape of the support device 10 can be adjusted so that it can effectively support the lordosis.

[0029] The lumbar support 100 shown here is a four-way lumbar support 100 in which the curvature of the support device 10 and the height of the arch apex S are adjustable. The curvature of the support device 10 results indirectly from the longitudinal component S Lthe position of the arch apex S, because the curvature of the support device 10 becomes stronger the greater the distance of the arch apex S from the back plane E in the longitudinal direction. The height of the arch apex S results from the height component S H the position of the arch apex S. In other embodiments, it is possible to connect either only the upper end O or only the lower end U to an angle adjuster 20, 25. In this case, it is referred to as a two-way lumbar support.

[0030] The lumbar support 100 has actuators 30, 35, each designed as shape memory actuators. The angle adjuster 20 is adjustable by the actuator 30 to change the upper inclination angle α. Likewise, the angle adjuster 25 is adjustable by the actuator 35 to change the lower inclination angle β. The actuators 30, 35 thus make adjusting the inclination angles α, β considerably easier. Shape memory actuators, in particular, are extremely quiet and can be operated with low energy consumption. Furthermore, they are particularly well suited for use in the lumbar support 100 because the angle adjusters 20, 25 require only small adjustment paths, where shape memory actuators apply large forces.

[0031] How Fig. As clearly shown in Figure 5, the lumbar support 100 has a locking device 40 for locking the lower angle adjuster 25. Furthermore, the lumbar support 100 can have a further locking device for locking the upper angle adjuster 20. By means of the locking device 40, the actuator 35 can be de-energized when the desired position of the arch apex S is reached. The arch apex S then remains in its position because the angle adjuster 25 is locked. Thus, a virtually consumption-free continuous operation of the lumbar support 100 is possible.

[0032] How Fig. As Figure 5 further shows, the actuator 35 has a drive train 36 that is frictionally connected to a floating bearing 37. The floating bearing 37 is slidably attached to the actuator 35 in the direction of the drive train 36. A tensile force acting on the drive train 36 moves the floating bearing 37 toward the drive train 36.

[0033] The locking device 40 has a wrap spring 41, which is accommodated in a wrap spring receptacle 43, and a wrap spring drive 42. The wrap spring 41 surrounds the floating bearing 37. The wrap spring drive 42 transfers the wrap spring 41 from a relaxed state to a tensioned state. In the relaxed state, the wrap spring 41 rests directly against the floating bearing 37. This creates a frictional force between the wrap spring 41 and the floating bearing 37, so that the wrap spring 41 locks the floating bearing 37 and thus the angle adjuster 25. In the tensioned state, the wrap spring 41 releases the floating bearing 37 and the angle adjuster 25.

[0034] The lumbar support 100 further comprises a mounting plate 50, a bearing element 55, a clamping element 60, and a coupling 65. The angle adjuster 25 is mounted on the mounting plate 50 by the bearing element 55. The support device 10 is clamped into the clamping element 60. Retaining wires 70 are guided to the mounting plate 50. The clamping element 60 has a connecting section 61, which is rotatably and displaceably mounted on the bearing element 55, and a coupling point 63. For this purpose, a slot-shaped recess 56 is provided on the bearing element 55. The connecting section 61 comprises a cylindrical bolt 62, which engages in the recess 56 and is connected to the loose bearing 37 of the actuator 35. The bolt 62 can be displaced along the recess 56 and rotated therein. The coupling 65 has a first end 65a and a second end 65b and is rigid.The first end 65a is rotatably connected to the clamping element 60 at the coupling point 63. The second end 65b is rotatably connected to the bearing element 55.

[0035] To adjust the position of the arch apex S, the actuator 35 causes the bolt 62 to move in the recess 56. The clamping element 60 is then moved translationally along the recess. Due to the connection to the rigid coupling 65, a rotational movement of the clamping element 60 about the bolt 62 also occurs. The clamping element 60, in which the lower end U of the support device 10 is clamped in a rotationally fixed manner, is tilted relative to the back plane E by the rotational movement, so that the lower inclination angle β is changed.

[0036] The Fig.3a to 3d and 4a to 4d clearly show the lumbar support 100 at different angles of inclination α, β as well as the corresponding positions of the angle adjusters 20, 25. Furthermore, it is evident how the combination of the positions of the angle adjusters 20, 25 results in different shapes of the support device 10 and, consequently, different positions of the arch apex S.

[0037] The lumbar support 100 according to the exemplary embodiments described here is thus continuously adjustable. The different positions of the arch apex S achieve different curvatures of the support device 10 and the heights of the arch apex S. The actuator travel required here is significantly shorter compared to conventional lumbar supports. Furthermore, the use of shape memory actuators allows for extremely quiet and energy-efficient implementation. List of reference symbols 10 Support device 11 Lumbar mat 12a Mat element 12b Mat element 12c mat element 12d mat element 12th mat element 12f mat element 12g mat element 12h mat element 20 angle adjusters 25 angle adjusters 30 Actuator 35 Actuator 36 drive train 37 loose bearings 40 locking device 41 Wrap spring 42 Wrap spring drive 43 Wrap spring holder 50 mounting plate 55 bearing element 56 recess 60 clamping element 61 connecting section 62 bolts 63 coupling point 65 paddock 65a first end 65b second end 70 retaining wire 100 lumbar support 200 seats 201 Backrest 202 Seat A extension axis B Reference plane E back level O upper end S arch apex S H Height component S L Longitudinal component U lower end α upper inclination angle β lower inclination angle

Claims

[1] Lumbar support (100) for a seat (200) defining a back plane (E), comprising: a support device (10) having an upper end (O) which encloses an upper angle of inclination (α) with the back plane (E) and a lower end (U) which encloses a lower angle of inclination (β) with the back plane (E) and forms a vault apex (S) which is in an adjustable position between the upper end (O) and the lower end (U); at least one angle adjuster (20, 25) connected to the upper end (O) or the lower end (U) of the support device (10) and suitable for changing the upper angle of inclination (α) or the lower angle of inclination (β) in order to adjust the position of the crown (S), and an actuator (30, 35) for adjusting the angle adjuster (20, 25); characterized bya bearing element (55) for the angle adjuster (20, 25) and by a coupling (65) having a first end (65a) and a second end (65b); wherein the angle adjuster (20, 25) has a clamping element (60) which comprises a connecting section (61) and a coupling point (63); wherein the connecting portion (61) is rotatably and displaceably mounted on the bearing element (55); wherein the first end (65a) of the coupling (65) is rotatably connected to the clamping element (60) at the coupling point (63) and the second end (65b) of the coupling (65) is rotatably connected to the bearing element (55) and wherein the actuator (30, 35) engages the connecting portion (61) to cause a movement of the clamping element (60) relative to the bearing element (55), by which the upper inclination angle (α) or the lower inclination angle (β) is changed. [2] Lumbar support (100) according to claim 1, characterized byan upper angle adjuster (20) connected to the upper end (O) and a lower angle adjuster (25) connected to the lower end (U). [3] Lumbar support (100) according to claim 1 or 2, characterized by that the support device (10) is clamped at the upper end (O) and / or at the lower end (U) in a rotationally fixed manner into the angle adjuster (20, 25). [4] Lumbar support (100) according to one of claims 1 to 3, characterized by that the support device (10) has a lumbar mat (11) which is provided with a plurality of mat elements (12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h) which are connected to one another in an articulated manner. [5] Lumbar support (100) according to claim 4, characterized by that the mat elements (12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h) have an extension axis (A) which runs substantially parallel to the back plane (E). [6] Lumbar support (100) according to one of claims 1 to 5, characterized bythat the actuator (30, 35) is designed as a shape memory actuator. [7] Lumbar support (100) according to one of claims 1 to 6, characterized by that the actuator (30, 35) is provided with a displaceably mounted loose bearing (37) which is connected to the connecting section (61). [8] Lumbar support (100) according to claim 7, characterized by that the clamping element (60) has a bolt (62) which is fastened to the loose bearing (37) for transmitting a displacement of the loose bearing (37) to the clamping element (60). [9] Lumbar support (100) according to one of claims 1 to 8, characterized by a locking device (40) for locking the angle adjuster (20, 25). [10] Lumbar support (100) according to claim 9, characterized byin that the locking device (40) has a wrap spring (41) and a wrap spring drive (42), wherein the wrap spring drive (42) is designed to transfer the wrap spring (41) from a relaxed state, in which the wrap spring (41) locks the angle adjuster (20, 25), into a tensioned state, in which the wrap spring (41) releases the angle adjuster (20, 25). [11] Lumbar support (100) according to one of claims 1 to 10, characterized by a mounting plate (50) on which the angle adjuster (20, 25) is mounted by the bearing element (55). [12] Seat (200), in particular for a motor vehicle, characterized by the lumbar support (100) according to one of claims 1 to 11.

Images