Motor vehicle seat with portions made from composite sheet

1. A motor vehicle seat comprising: an underframe; two side parts; a seat back hinge mounting; and one seat back that is connected to said two side parts by the seat back hinge mounting, said underframe comprising a bridge disposed between seat rails; an electric motor carried by the bridge; and a longitudinal adjusting device driven by the electric motor; wherein the bridge comprises composite sheet material comprising a first soft material portion interposed between two rigid layers and is connected to the seat rails in such a manner that sound transmission between the bridge and the seat rails connected thereto is dampened, and the bridge is connected to the seat rails through connecting means, the connecting means being sufficiently surrounded by a second soft material portion in such a manner that the connecting means does not directly contact the bridge and sound transmission is dampened between the bridge and the seat rails.

2. The motor vehicle seat as set forth in claim 1 , wherein the portions in contact with the adjusting device are made from the composite sheet material.

3. The motor vehicle seat as set forth in claim 2 , wherein the rigid layers are metallic.

4. The motor vehicle seat as set forth in claim 3 , wherein at least one of the first and second soft material portions is viscoelastic.

5. The motor vehicle seat as set forth in claim 1 , wherein the portions of the motor vehicle seat in contact with the electric motor are made from the composite sheet material.

6. The motor vehicle seat as set forth in claim 5 , wherein the rigid layers are metallic.

7. The motor vehicle seat as set forth in claim 6 , wherein at least one of the first and second soft material portions is viscoelastic.

8. The motor vehicle seat as set forth in claim 1 , wherein the rigid layers are metallic.

9. The motor vehicle seat as set forth in claim 8 , wherein at least one of the first and second soft material portions is viscoelastic.

10. The motor vehicle seat as set forth in claim 1 , wherein the bridge is formed in a forming step, at least one of the first and second soft material portions comprises viscoelastic material that comprises a curable material, the curable material of the viscoelastic material is not yet cured when performing the forming step, and is cured at a later stage of completion of the motor vehicle seat.

11. The motor vehicle seat as set forth in claim 1 , wherein the bridge has a border area that is angled.

12. The motor vehicle seat as set forth in claim 1 , wherein the bridge further has two flat end regions for fastening the bridge to the seat rails, the end regions are not made from the composite sheet material.

13. The motor vehicle seat as set forth in claim 1 , wherein portions of the motor vehicle seat in addition to the bridge are made from the composite sheet material.

14. The motor vehicle seat as set forth in claim 1 , wherein at least one of the first and second soft material portions are viscoelastic.

15. The motor vehicle seat as set forth in claim 2 , wherein at least one of the first and second soft material portions are viscoelastic.

16. The motor vehicle seat as set forth in claim 5 , wherein at least one of the first and second soft material portions are viscoelastic.