Film airbags

Abstract

Inflatable airbag for a vehicle which is deployed in the event of an accident involving the vehicle to provide protection for an occupant of the vehicle includes a plurality of ribbons coupled together to define an enclosed, fluid-retaining space and a layer of film laminated on at least one of an outer side of the woven ribbons and an inner side of the ribbons. The ribbons may be made from polypropylene, polyethylene, polyester or polyamide and the layers of film may be made from polyethylene, polyurethane, polyester or polyamide. The ribbons and layers of film may be made of the same or different materials.

The invention claimed is: 
     
       1. An inflatable airbag for a vehicle which is deployed in the event of an accident involving the vehicle to provide protection for an occupant of the vehicle, comprising:
 a plurality of ribbons coupled together to define an enclosed, fluid-retaining space; and   a layer of film laminated on at least one of an outer side of the woven ribbons and an inner side of the ribbons.   
     
     
       2. The airbag of  claim 1 , wherein the ribbons are made from polypropylene, polyethylene, polyester or polyamide and the layers of film are made from polyethylene, polyurethane, polyester or polyamide. 
     
     
       3. The airbag of  claim 1 , wherein said plurality of ribbons comprises a first set of ribbons oriented in a first direction and a second set of ribbons oriented in a second direction different than the first direction, said first and second sets of ribbons being attached together. 
     
     
       4. The airbag of  claim 3 , wherein said first and second sets of ribbons are woven together. 
     
     
       5. The airbag of  claim 1 , wherein said ribbons are formed in separate pieces, further comprising an elastomer arranged at seams at which said pieces are coupled together to form the space. 
     
     
       6. The method of  claim 5 , wherein the elastomer is polyurethane. 
     
     
       7. The method of  claim 6 , wherein the elastomer is part of the pieces of airbag material. 
     
     
       8. The airbag of  claim 1 , wherein said ribbons are coupled together to define a side curtain airbag. 
     
     
       9. The airbag of  claim 1 , wherein said ribbons are coupled together to define a knee airbag. 
     
     
       10. The airbag of  claim 1 , wherein said ribbons and said layers of film are made of different materials. 
     
     
       11. The airbag of  claim 1 , wherein a layer of film is laminated on both the outer side and the inner side of the ribbons. 
     
     
       12. A method for forming an inflatable airbag for a vehicle which is deployed in the event of an accident involving the vehicle to provide protection for an occupant of the vehicle, comprising:
 coupling a plurality of ribbons together to define an enclosed, fluid-retaining space; and   laminating a layer of film on at least one of an outer side of the woven ribbons and an inner side of the ribbons.   
     
     
       13. The method of  claim 12 , wherein the plurality of ribbons comprises a first set of ribbons oriented in a first direction and a second set of ribbons oriented in a second direction different than the first direction, the step of coupling the ribbons together comprising weaving the first and second sets of ribbons together. 
     
     
       14. The method of  claim 12 , wherein the ribbons are formed in separate pieces, further comprising arranging an elastomer at seams at which the pieces are coupled together to form the space. 
     
     
       15. The method of  claim 12 , wherein a layer of film is laminated on both the outer side and the inner side of the woven ribbons. 
     
     
       16. A method for forming an inflatable airbag for a vehicle which is deployed in the event of an accident involving the vehicle to provide protection for an occupant of the vehicle, comprising:
 providing a plurality of pieces of airbag material, the pieces having substantially the same thickness and composition; and   joining the pieces together at seams using an elastomer such that the elastomer constitutes a bonding agent for joining the pieces of material together and stress at the seams is distributed along the seams and possibly into the seams.   
     
     
       17. The method of  claim 16 , wherein the elastomer is polyurethane. 
     
     
       18. The method of  claim 16 , wherein the elastomer is part of the pieces of airbag material. 
     
     
       19. A method for forming an inflatable film airbag for a vehicle which is deployed in the event of an accident involving the vehicle to provide protection for an occupant of the vehicle, comprising:
 coupling a first airbag portion to a second airbag portion to define an enclosed, fluid-retaining space sealed at a seam between the first and second airbag portions; 
 each of the first and second airbag portions being produced by
 providing at least two uniaxially oriented films each comprising a set of uniaxially oriented ribbons, the ribbons in each of the films being stretched in a single direction to provide the uniaxial orientation and; 
 attaching the uniaxially oriented films together in a state in which each of the films having sets of ribbons has a different orientation direction such that the films ribbons in one set are at a non-parallel angle to one another the ribbons in another set; and 
 weakly laminating the films together at least one film layer to the uniaxially oriented films, the airbag being made only from film. 
 
 
     
     
       20. The method of  claim 19 , wherein two uniaxially oriented films are provided and the orientation direction directions of the films is sets of ribbons in the two uniaxially oriented films are perpendicular to one another. 
     
     
       21. The method of claim 19, further comprising selecting material of the ribbons from polypropylene, polyethylene, polyamide and polyester. 
     
     
       22. The method of claim 19, further comprising selecting material of each of the at least one film layer from polyethylene, polyester, polyamide, and polyurethane. 
     
     
       23. The method of claim 19, wherein the step of laminating at least one film layer to the uniaxially oriented films comprises laminating at least one film layer to an inner side of the uniaxially oriented films and laminating at least one film layer to an outer side of the uniaxially oriented films. 
     
     
       24. The method of claim 23, further comprising using different film layers on the inner and outer sides of the uniaxially oriented films. 
     
     
       25. The method of claim 19, wherein the step of laminating at least one film layer to the uniaxially oriented films comprises laminating at least one film layer to an inner side of the uniaxially oriented films. 
     
     
       26. The method of claim 19, wherein the step of laminating at least one film layer to the uniaxially oriented films comprises laminating at least one film layer to an outer side of the uniaxially oriented films. 
     
     
       27. The method of claim 19, wherein the step of laminating at least one film layer to the uniaxially oriented films comprises bonding the ribbons and the at least one film layer together. 
     
     
       28. The method of claim 19, wherein the step of attaching the uniaxially oriented films together comprises weaving the ribbons together. 
     
     
       29. The method of claim 19, wherein the step of attaching the uniaxially oriented films together comprises layering the sets of ribbons on top of one another and then bonding the layered sets of ribbons together.