Patent Application
20070216207
The present invention relates to a lumbar support, as can be incorporated into backrests of seats of all kinds, for example motor vehicle seats, for supporting the loin and spinal column region.
Known lumbar supports of the kind described above comprise at least one archable supporting element, which is called lumbar support basket or lumbar support plate and can consist of a wire-lattice or integral plastic injection moulding, for example. Furthermore, known lumbar supports comprise an adjustment mechanism, by means of which the curvature of the at least one archable supporting element of the lumbar support can be adjusted. An adjustment mechanism known from the prior art comprises a Bowden cable arrangement, wherein the sleeve of the Bowden cable arrangement is supported on an end section of the archable supporting element, while the wire of the Bowden cable arrangement displaceably mounted in the sleeve is attached at another end section of the archable supporting element, so that through movement of the wire in the sleeve of the Bowden cable arrangement the two end sections are moved nearer or further from one another, in order in this way to adjust the curvature of the supporting element. The wire in the sleeve of the Bowden cable arrangement can be adjusted either manually, for example, by means of a hand-wheel or automatically by means of a suitable motor drive.
Lumbar supports of the kind described above are used, for example, in backrests of motor vehicle seats. In this case, the lumbar supports carry out a multiple support function, since both the lower spinal column region, that is to say the loin or lordosis region, and the middle spinal column region and the upper spinal column region must be sufficiently supported, in order to reliably prevent fatigue symptoms when sitting over longer periods as well as possibly even damage to health. For this reason, the use of lumbar supports, the arching or curvature of which can be adjusted, is of utmost importance, so that the curve apex can be adapted to the particular needs of the individual person. This not only applies to lumbar supports in motor vehicle seats, but is also valid for applications in backrests of seats of any kind, for example office chairs etc.
With the aid of conventional adjustable lumbar supports, a sufficient supporting functionality can be ensured in most cases as a result of a user adjusting the curvature of the archable supporting element of the lumbar support to his spinal column corresponding to his spinal column form.
The human spinal column, however, is formed in extremely individual ways. Therefore it may be the case that a convex curvature of the supporting surface, that is to say the archable supporting element, of the lumbar support is perfectly helpful and pleasant for one user, while the same curvature is unpleasant and possibly even harmful for another user. In particular, spinal column forms are also conceivable, where a convex curvature of the lumbar support may over the long term lead to substantial damage to health. Moreover, heed should be paid to the fact that the human spinal column deforms with increasing sitting duration, whereby furthermore with increasing sitting duration more robust support is necessary in the lordosis region of the individual user.
Consequently, in principle there is a need for a lumbar support, which takes account of the problems described above and permits greater flexibility and adaptability to the individual spinal column form, respectively the individual spinal column characteristics of the various users.
This object is achieved according to the invention by a lumbar support with the features of Claim 1. The sub-claims in each case define preferred and advantageous embodiments of the present invention.
The lumbar support according to the invention comprises at least one archable supporting element as well as an adjustment mechanism for adjusting the curvature of the archable support element, wherein the adjustment mechanism is configured in such a manner that it not only allows a curvature of the archable supporting element in contrast to lumbar supports into a first curvature direction, in which the archable supporting element forms a convex supporting surface, but furthermore also a curvature into a second curvature direction, in which the archable supporting element forms a concave supporting surface. Therefore, the lumbar support according to the invention allows both a “positive” curvature and a “negative” curvature, so that the lumbar support, in comparison to conventional lumbar supports, can be substantially better adapted to the specific requirements of an individual user.
The adjustment mechanism advantageously is also configured in such a manner that the second curvature direction is aimed substantially opposite to the first curvature direction out of the plane of the laminar supporting element.
By using a circumferential Bowden cable system, it can be achieved that the curvature of the archable supporting element can be adjusted and adapted in both curvature directions with the aid of this circumferential Bowden cable system. Likewise, a mechanical adjustment mechanism is also conceivable, which engages the curving apex, respectively point of curvature of the archable supporting element and controls the curvature of the archable supporting element in both curvature directions, whereby such a mechanical adjustment mechanism can be implemented with the aid of a spindle drive, for example.
The adjustment mechanism according to the invention consists in principle of two adjustment means, whereby the first adjustment means bring about the curvature of the archable supporting element into the first curvature direction, while the second adjustment means bring about the curvature of the archable supporting element into the second curvature direction. The two adjustment means can be coupled with one another via a common actuating device. Furthermore, however, it is also conceivable to form the two adjustment means separately and divided from one another.
The adjustment means, for example, can be formed in each case by Bowden cable arrangements, wherein the sleeve of the first Bowden cable arrangement is supported on a first end section of the archable supporting element and the wire of the first Bowden cable arrangement working as a tensioning member acts upon a second end section of the archable supporting element, so that by adjusting the wire inside the sleeve of the first Bowden cable arrangement the two end sections are moved, in particular pulled closer or further from one another. Advantageously, the wire can be guided from the first end section via reversing means, in particular in the form of a reversing roller, to the second end section on and off back to the first end section and attached there to the archable supporting element, so that the curvature of the archable supporting element can therefore be adjusted into the first curvature direction more effectively and with less expenditure of energy. The wire of the first Bowden cable arrangement is preferably guided along the back of the archable supporting element. The sleeve of the second Bowden cable arrangement likewise can be supported on the first end section of the archable supporting element, whereby starting from this first end section the wire of the second Bowden cable arrangement is guided to the second end section and from there again via suitable reversing means back to the first end section and fastened here. In this case, the wire of the second Bowden cable arrangement preferably firstly runs along the back of the archable supporting element, the wire of the second Bowden cable arrangement then being guided through an opening in the archable support element to the front of the same and being reversed there. Subsequently, the wire returns through a further opening in the archable supporting element to the back of the same and from there is guided along the back to its fastening point on the first end section of the archable supporting element. This method of guidance also allows particularly effective arching of the archable supporting element into the second curvature direction with little expenditure of energy.
The reversing roller mentioned above can be pivotably attached to the second end section of the archable supporting element, whereby the reversing roller can be swivelled out of the plane of the archable supporting element, so that therefore the wire of the first Bowden cable arrangement can run as smoothly as possible with adjustment using as little expenditure of energy as possible.
The archable supporting element can comprise a first laminar supporting section and a second laminar supporting section, which are connected via at least one flexible longitudinal bar running in the longitudinal direction of the supporting element. The flexible longitudinal bar is configured in such a manner that it is flexible in the longitudinal direction of the supporting element, so that even if the lumbar support is abused, that is to say if the lumbar support is loaded to an unacceptably high degree, breakage or damage of the lumbar support is prevented due to the longitudinal flexibility of this longitudinal bar. For this purpose, the longitudinal bar can have in the longitudinal direction elevations and depressions in alternating succession in the form of a concertina, which in each case runs in the cross direction of the longitudinal bar. Preferably two such longitudinal bars are provided situated at a distance from one another in the lateral direction of the archable supporting element.
The adjustment mechanism of the lumbar support according to the invention can be operated both manually and motor-driven. In this case, it is possible that common actuating means are provided for adjusting the curvature of the archable supporting element both into the first curvature direction and into the second curvature direction, in such a manner that adjustment of the curvature into the first curvature direction at the same time actively contributes to a reduction of the curvature in the second curvature direction and vice versa, so that with little expenditure of energy effective adjustment of the curvature of the lumbar support according to the invention is possible in both curvature directions.
The lumbar support can be associated with a further adjustment mechanism for adjusting the archable supporting element along guidance means, for example guide rods, whereby with the aid of this further adjustment mechanism, which likewise can be configured in the form of a Bowden cable arrangement, in particular in the form of a circumferential Bowden cable system, vertical adjustment of the lumbar support in a backrest of a seat is possible. For this reason, the sleeve of the Bowden cable arrangement can be supported on a mounting plate coupled with the guidance means, while the wire of the Bowden cable arrangement is coupled with the archable support element, preferably via a spring element. Also, in respect to the vertical adjustment of the lumbar support, two separate Bowden cable arrangements can be provided for adjusting the archable supporting element into a first longitudinal direction along the guidance means, respectively for adjusting the archable supporting element into a second longitudinal direction opposite the former along the guidance means, whereby if a circumferential Bowden cable system is used, the two Bowden cable arrangements can be coupled with one another in such a way that tensioning the one Bowden cable arrangement at the same time leads to relaxing the other Bowden cable arrangement and vice versa.
The lumbar support according to the invention is suitable for use in backrests of motor vehicle seats or office chairs, but without being limited to this preferred scope of application. In principle, the lumbar support according to the invention can be used wherever individual and reliable as possible support of the spinal column, in particular the loin or lordosis region of the spinal column of a user is wanted. Thus, for example, incorporation of the lumbar support according to the invention is also conceivable in therapeutic cushions, mattresses or similar.
The archable supporting element of the lumbar support according to the invention is preferably produced as a plastic integral laminar part, whereby however the invention can also be applied to lumbar supports with multi-part archable supporting elements and in particular also to lumbar supports with lattice mats as archable support elements or similar.
The present invention is described in detail below with reference to the drawing on the basis of a preferred embodiment.
In
The lumbar support comprises an archable supporting element, which dependent on the actual embodiment is also described as a lumbar support plate or a lumbar support basket. The archable supporting element comprises a first laminar supporting section 1 and a second laminar supporting section 2, it being possible to make the two supporting sections 1, 2 out of plastic in each case. The supporting sections 1, 2 are connected with one another via longitudinal bars 3, which can be formed integrally with the supporting sections 1, 2 or can be fastened to them in an arbitrary way. The longitudinal bars 3 in each case are strip-like in shape and have a wave- or concertina-like structure in such a manner that in the longitudinal direction they have elevations and depressions in alternating succession and are thus flexibly formed. Due to this configuration, the longitudinal bars 3 are flexible in the longitudinal direction in such a manner that when the supporting sections 1, 2 are loaded to an excessively high degree, that is to say in a so-called case of abuse, they allow flexible resilience of the entire lumbar support, since they can be compressed dependent on the load to a greater or lesser degree due to the elevations and depressions in alternating succession. At the same time, however, the longitudinal bars 3 are configured in such a manner that they provide a sufficiently high degree of rigidity of the lumbar support in respect to a normal load regardless of their longitudinal flexibility. In principle, only a longitudinal bar 3 of this kind or more than two longitudinal bars 3 of this kind can also be provided between the two supporting sections 1, 2.
The supporting sections 1, 2, which serve as an archable supporting element and on their front provide a resting or supporting surface for a person leaning against it, are displaceably mounted along rods 4, which can be curved as shown in
From the illustration of
Furthermore, the lumbar support shown in
This will be described in detail below on the basis of
The adjustment mechanism of the lumbar support illustrated in
The adjustment mechanism provided for the convex curvature as in the case of conventional lumbar supports is substantially arranged and effective at the back of the lumbar support. With the embodiment illustrated, this adjustment mechanism comprises a Bowden cable, the sleeve 8 of which as shown in
From the above description, it is clearly evident that by tensioning the wire 9 with the aid of the Bowden cable, the lower end section of the supporting section 2 can be moved toward the upper end section of the supporting section 1, so that dependent on the degree of tensioning of the wire 9 the desired convex curvature of the supporting sections 1, 2 is achieved, as illustrated as an example on the left of
The adjustment mechanism for the concave curvature of the supporting sections 1, 2 likewise comprises a Bowden cable arrangement, wherein the sleeve 14 of this Bowden cable arrangement just as the sleeve 8 of the other Bowden cable arrangement is supported at the upper end section of the supporting section 1 on a socket or similar. The wire 15 of this Bowden cable arrangement starting from the upper end section of the supporting section 1 runs downward firstly along the back of the upper supporting section 1, whereby between the lower end section of the supporting section 1 and the longitudinal bar 3 attached to it on the right in
As can be seen in
As shown in
The reversing means 17 shown in
From the above explanation of
Preferably, the two Bowden cables 8, 9 or 14, 15, which are provided for the convex, respectively concave curvature of the archable supporting element comprising the two supporting sections 1, 2 (as well as the two longitudinal bars 3), similar to the Bowden cables 18, 19, or 21, 22 provided for the vertical adjustment, form a circumferential Bowden cable system in such a manner that tensioning of the one Bowden cable at the same time accompanies a relaxing of the other Bowden cable and vice versa. The two Bowden cables 8, 9 or 14, 15 can therefore—as indicated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 55 659.1 | Nov 2003 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP04/13396 | 11/24/2004 | WO | 1/22/2007 |
