Adjusting device for a lumbar support and method of adjusting a lumbar support

1. An adjusting device for a lumbar support, comprising:

a pair of spaced guide members;

an adjusting member coupled to said pair of guide members, said adjusting member being displaceable along said pair of guide members and configured such that said lumbar support is adjusted when said adjusting member is displaced; and

a drive mechanism for effecting an adjustment of said lumbar support, said drive mechanism comprising:

a motor provided on said adjusting member so as to be displaceable along said guide members jointly with said adjusting member; and

a spindle transmission, said spindle transmission comprising a spindle nut threadingly engaged with a shaft, said spindle nut being provided on said adjusting member.

2. The adjusting device of claim 1 , said shaft being disposed so as to extend substantially parallel to said guide members, said drive mechanism being configured such that actuation of said motor effects a relative displacement of said adjusting member and said shaft along a longitudinal direction of said shaft.

3. The adjusting device of claim 2 , wherein said drive mechanism is configured to displace said adjusting member relative to said shaft.

4. The adjusting device of claim 1 , wherein said shaft is flexible.

5. The adjusting device of claim 1 , further comprising:

spaced cross members respectively extending in between said pair of guide members, wherein ends of said shaft are attached to each one of said cross members.

6. The adjusting device of claim 1 , wherein said drive mechanism is configured to displace said adjusting member along said guide members.

7. The adjusting device of claim 1 , wherein said shaft is mounted so as to be pivotable about an axis which is perpendicular to a longitudinal axis of said shaft.

8. The adjusting device of claim 1 , wherein said drive mechanism further comprises:

at least one worm transmission which is coupled between said motor and said spindle transmission.

9. The adjusting device of claim 1 , wherein said spindle nut of said spindle trans-mission is mounted on said adjusting member so as to be pivotable relative to said adjusting member about an axis which is perpendicular to a longitudinal axis of said spindle nut.

10. The adjusting device of claim 1 , further comprising:

a further adjusting member which is displaceable along said pair of guide members, wherein said drive mechanism is configured so that, upon actuation of said motor, at least one of said adjusting member and said further adjusting member is displaced relative to said guide members.

11. The adjusting device of claim 10 , further comprising:

a further drive mechanism comprising a further motor, said further motor being provided on one of said adjusting member and said further adjusting member.

12. The adjusting device of claim 11 , wherein said drive mechanism and said further drive mechanism are configured such that said adjusting member and said further adjusting member are displaced in the same direction along said guide members upon actuation of one of said motor and said further motor, and that said adjusting member and said further adjusting member are displaced relative to each other upon actuation of the other one of said motor and said further motor.

13. The adjusting device of claim 1 , further comprising:

at least one arching member which is respectively coupled to said adjusting member and said further adjusting member.

14. A lumbar support apparatus, comprising:

a lumbar support; and

the adjusting device of claim 1 .

15. A method of adjusting a lumbar support, comprising

displacing an adjusting member along a pair of guide members in order to adjust said lumbar support,

said lumbar support being adjusted by means of a drive mechanism comprising a motor and a shaft, the shaft being operatively coupled to said motor so that said adjusting member and said shaft are displaced relative to each other when said motor is actuated, wherein said motor is provided on said adjusting member so that the motor is displaced along said guide members jointly with said adjusting member, said drive mechanism comprising a spindle transmission, a spindle nut of said spindle transmission being provided on said adjusting member, said spindle nut being threadingly engaged with said shaft.

16. An adjusting device for a lumbar support, comprising:

at least one guide member;

an adjusting member coupled to said at least one guide member, said adjusting member being displaceable along said at least one guide member and configured such that said lumbar support is adjusted when said adjusting member is displaced; and

a drive mechanism for effecting an adjustment of said lumbar support, said drive mechanism comprising:

a motor; and

a spindle transmission coupled to said motor, said spindle transmission comprising a spindle nut threadingly engaged with a shaft, said shaft comprising a metal core.

17. The adjusting device of claim 16 , wherein said shaft is a flexible shaft.

18. The adjusting device of claim 16 , wherein said metal core of said shaft comprises a plurality of metal wires.

19. The adjusting device of claim 16 , wherein said shaft has an external thread formed on an outer surface of said metal core.

20. An adjusting device for a lumbar support, comprising:

at least one guide member;

an adjusting member coupled to said at least one guide member, said adjusting member being displaceable along said at least one guide member and configured such that said lumbar support is adjusted when said adjusting member is displaced; and

a drive mechanism for effecting an adjustment of said lumbar support, said drive mechanism comprising:

a motor; and

a spindle transmission coupled to said motor, said spindle transmission comprising a spindle nut threadingly engaged with a shaft, said shaft being a flexible shaft.