Pre-weakening of fabric covered airbag doors

• US 20040164531A1
• Filed: 02/24/2003
• Published: 08/26/2004
• Est. Priority Date: 02/24/2003
• Status: Active Grant

• Current Assignee: Collins & Aikman Automotive Company Incorporated
• Original Assignee: Collins & Aikman Automotive Company Incorporated
• Inventors: Sullivan, A. Hardy, Totten, Brian, Gray, John D., Batchelder, Bruce, Weissert, Ulrich, Riha, Keith A.
• Granted Patent: US 7,100,941 B2
• Time in Patent Office: Days
• US Class Current: 280/732
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/38 Fabrics, fibrous materials
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: B29C 37/0032 the coating being applied upon the mould surface before introducing the moulding compound, e.g. applying a gelcoat B29C44/14 and B29C44/32 take precedence
• CPC Class Codes: B29C 59/007 Forming single grooves or ribs, e.g. tear lines, weak spots by moulding B29C37/0057; folding lines B29C53/06; in metal articles B21D17/00; by cutting B26D3/08
• CPC Class Codes: B29C 59/16 by wave energy or particle radiation , e.g. infrared heating B29C59/007 takes precedence
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B29L 2031/3005 Body finishings
• CPC Class Codes: B32B 2262/02 Synthetic macromolecular fibres
• CPC Class Codes: B32B 2605/003 Interior finishings
• CPC Class Codes: B32B 3/10 characterised by a discontinuous layer, i.e. formed of separate pieces of material
• CPC Class Codes: B32B 3/266 characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• CPC Class Codes: B32B 43/003 Cutting
• CPC Class Codes: B32B 5/026 Knitted fabric
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B60R 21/2165 characterised by a tear line for defining a deployment opening
• CPC Class Codes: D03D 1/02 Inflatable articles
• CPC Class Codes: D03D 15/573 : Tensile strength
• CPC Class Codes: D03D 27/00 : Woven pile fabrics
• CPC Class Codes: D04B 19/00 : Unravelling knitted fabrics
• CPC Class Codes: D06M 11/38 : Oxides or hydroxides of elements of Groups 1 or 11 of the Periodic Table
• CPC Class Codes: D06M 23/16 : Processes for the non-uniform application of treating agents, e.g. one-sided treatment; Differential treatment
• CPC Class Codes: D06Q 1/02 : Producing patterns by locally destroying or modifying the fibres of a web by chemical actions, e.g. making translucent
• CPC Class Codes: D10B 2201/02 : Cotton
• CPC Class Codes: D10B 2201/04 : Linen
• CPC Class Codes: D10B 2201/06 : Jute
• CPC Class Codes: D10B 2201/20 : Cellulose-derived artificial fibres
• CPC Class Codes: D10B 2201/24 : Viscose
• CPC Class Codes: D10B 2201/28 : Cellulose esters or ethers, e.g. cellulose acetate
• CPC Class Codes: D10B 2211/02 : Wool
• CPC Class Codes: D10B 2321/021 : polyethylene
• CPC Class Codes: D10B 2321/022 : polypropylene
• CPC Class Codes: D10B 2321/06 : polymers of unsaturated alcohols, e.g. polyvinyl alcohol, or of their acetals or ketals
• CPC Class Codes: D10B 2321/10 : polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide
• CPC Class Codes: D10B 2331/02 : polyamides D10B2331/08 takes precedence
• CPC Class Codes: D10B 2331/021 : aromatic polyamides, e.g. aramides
• CPC Class Codes: D10B 2331/04 : polyesters, e.g. polyethylene terephthalate [PET]
• CPC Class Codes: D10B 2401/041 : thermoplastic; thermosetting
• CPC Class Codes: D10B 2401/063 : high strength
• CPC Class Codes: D10B 2505/124 : Air bags

Abstract

A variety of embodiments are disclosed, in both apparatus and method form, that relate to the use of fabric material in the manufacture of an air bag deployment system. In addition, fabric weakening is disclosed according to a technique that does not result in physical alteration of the fabric. This invention therefore includes an air bag cover for an air bag safety system for a vehicle comprising a fabric outer layer having a frontside and a backside and a substrate containing an opening wherein the opening has a periphery. The substrate is preferably formed by low pressure molding, wherein the fabric outer layer overlies the opening in the substrate, and wherein the fabric outer layer is weakened at a location that is adjacent or overlies the substrate opening periphery.

Claims

1. An air bag cover for an air bag safety system for a vehicle comprising:

a fabric outer layer having a front side and a backside,

a substrate containing an opening, said opening having a periphery, the substrate formed by low pressure molding,

wherein the fabric outer layer overlies the opening in the substrate, and wherein the fabric outer layer is weakened at a location that is adjacent or overlies said periphery.

2. The air bag cover of claim 1, wherein said opening in said substrate is closed by a door formed integrally with said substrate, said door having an outer edge.

3. The air bag cover of claim 2, wherein the substrate is provided with a weakening groove along the periphery of said opening and said weakening groove defines at least a portion of said outer edge of said door.

4. The air bag cover of claim 3, wherein the weakening groove comprises any of a series of holes and slots which partially or totally penetrate said substrate.

5. The air bag cover of claim 1, wherein the fabric outer layer includes a backing layer positioned between said fabric outer layer and said substrate.

6. The air bag cover of claim 1, wherein said fabric outer layer is weakened by partially cutting into the backside of said fabric outer layer.

7. The air bag cover of claim 5, wherein said fabric outer layer and said backing layer are weakened by cutting through said backing layer and into said fabric outer layer backside.

8. The air bag cover of claim 1 wherein said weakening of said fabric outer layer is provided by cutting with a laser or a knife.

9. The air bag cover of claim 5 wherein said weakening of said fabric outer layer including said backing layer is provided by cutting with a laser or knife.

10. The air bag cover of claim 8, wherein said knife is a sonic knife or a heated knife.

11. The air bag cover of claim 9 wherein said knife is a sonic knife or a heated knife.

12. The air bag cover of claim 7, wherein at least one of said fabric outer layer, said backing layer or said substrate are weakened by the application of a knife or a laser and at least partially cutting through any one of said fabric outer layer, said backing layer or said substrate.

13. The air bag cover of claim 6 wherein the fabric outer layer is weakened in a pattern that lies just outside of the opening in the substrate that is closed by the door.

14. The air bag cover of claim 7 wherein the fabric outer layer is weakened in a pattern a portion of which lies outside of the opening in the substrate that is closed by the door.

15. The air bag cover of claim 1 wherein said low pressure molding comprises sequential injection molding.

16. The low pressure molding of claim 15 comprising reaction injection molding, injection molding, injection-compression molding, gas assist injection molding, structural foam molding, gas counter-pressure injection molding, extrusion molding.

17. A method for manufacturing an air bag cover layer for an air bag cover, the air bag cover outer layer comprising a woven or knitted fabric material and including an inner surface, an outer surface, a tear seam region, and a non-tear seam region surrounding the tear seam region, the fabric material of the tear seam region being photodegraded to a greater extent than the fabric material of the non-tear seam region, said method comprising the steps of:

(a) forming the air bag cover outer layer from a fabric material;

(b) masking the non-tear seam region of the air bag cover outer layer with substance generally opaque to wavelengths of electromagnetic radiation that are capable of weakening the fabric material of the air bag cover outer layer;

(c) illuminating the tear seam region of at least one of the inner and outer air bag cover outer layer surfaces with electromagnetic radiation of sufficient intensity and within a range of wavelengths that will weaken the fabric material of the air bag cover layer;

(d) continuing to illuminate the air bag cover outer layer until the electromagnetic radiation has weakened the fabric material of the unmasked tear seam region.

18. A method for manufacturing an air bag cover as set forth in claim 17 in which said step of illuminating includes an illumination range restricted to ultraviolet light having wavelengths less than 320 nanometers.

19. A method for manufacturing an air bag cover as set forth in claim 18 in which said step of forming the air bag cover outer layer includes the step of including a compound in the fabric material which promotes air bag cover outer layer photodegradation caused by UV radiation having wavelengths less than 320 nanometers.

20. A method for manufacturing an air bag cover layer for an air bag cover, the air bag cover layer comprising a woven or knitted fabric material and including an inner and an outer surface, a tear seam region, a non-tear seam region surrounding the tear seam region, the fabric material of the tear seam region being weakened to a greater extent than the fabric material of the non-tear seam region, said method comprising the steps of:

(a) forming the air bag cover layer from a fabric material;

(b) masking the non-tear seam region of the air bag cover outer layer with a substance that is unaffected by caustic solution, said caustic solution being capable of weakening the fabric material of the air bag cover layer;

(c) coating the tear seam area of at least one of the inner and outer air bag cover layer surfaces with said caustic solution to weaken the fabric material of the air bag cover layer;

(d) continuing to coat the air bag cover layer until the caustic solution has weakened the fabric material of the unmasked tear seam region; and

rinsing and drying the fabric material.

21. A method for manufacturing an air bag cover layer as set forth in claim 20 in which the step of coating the fabric with caustic solution includes the step of spraying said tear seam region with steam.

22. A method for manufacturing an air bag cover outer layer for an air bag cover, the air bag cover outer layer comprising a woven or knitted fabric material and including an inner and an outer surface, a tear seam region, a non-tear seam region surrounding the tear seam region, the fabric material of the tear seam region being weakened by a laser to a greater extent than the fabric material of the non-tear seam region, said method comprising the steps of:

(a) forming the air bag cover outer layer from a fabric material;

(b) projecting a laser beam onto any one of the inner and outer surface of the fabric;

(c) continuing to project the laser in the tear seam region of the fabric until the laser energy has weakened the fabric material.

23. The method of claim 22 wherein said weakening represents a reduction of at least 30% in tensile strength of the fabric material.

24. A method of manufacturing a trim panel assembly of an automotive vehicle having an integral airbag deployment door for normally concealing an inflatable airbag of the vehicle, said method comprising the steps of:

(a) molding a plastic substrate using a low pressure molding process and having a trim panel portion mountable to a support structure of the vehicle, an integral airbag door portion, and a molded-in channel extending into the substrate from an outer surface thereof interconnecting the trim panel and door portions of the substrate as a unitary structure and defining a tear seam line for the door portion enabling the door portion to separate and swing outwardly of the trim panel portion in response to deployment of the airbag;

(b) preparing a cover comprising an outer layer of woven or knitted fabric;

(c) applying an adhesive to the outer surface of at least the trim panel portion of the substrate;

(d) positioning the cover over the outer surface of the substrate and drawing a vacuum on the substrate to urge the cover against the trim panel and door portions of the substrate and down into the channel; and

(e) severing the cover within the channel to reduce the resistance that the cover may offer to the separation and outward swinging of the door portion of the substrate upon deployment of the airbag.

25. In the method of claim 24, preventing the adhesive from being applied to the door portion of the substrate, and removing a severed portion of the cover overlying the door portion to reveal the underlying door portion.

26. The method of claim 24 including the additional step of cutting a groove at least partially through the substrate from the side opposite the outer surface of the substrate and in line with the molded-in channel.

27. The method of claim 26 wherein the groove comprises intermittent slots or holes.

28. The air bag cover of claim 24 wherein said substrate formed by low pressure molding comprises the use of sequential injection molding.

29. The low pressure molding of claim 28 comprising reaction injection molding, injection molding, injection-compression molding, gas assist injection molding, structural foam molding, gas counter-pressure injection molding, extrusion molding.

30. A cover assembly for concealing an air bag restraint system including an air bag, the cover assembly comprising,

a panel defining an air bag opening,

a fabric covering attached to the panel so that the covering covers the air bag opening in a tensioned manner, said covering having a front side and a backside,

the fabric covering being positioned with respect to the air bag so that the fabric covering is engaged by the air bag when it is inflated for deployment into a passenger compartment, and

the fabric covering having a single tear seam that is ruptured when the fabric covering is impacted by the inflating air bag to form an opening for deployment of the air bag into the passenger compartment, the tear seam having ends spaced from the panel.

31. The air bag covering as defined in claim 30 wherein the fabric covering comprises a woven or knitted fabric having a single tear seam and a backing layer that exposes the single tear seam.

32. The cover assembly of claim 30 wherein the tear seam in the fabric covering is formed by cutting partially through said fabric covering from the backside using one of a laser and a knife.

33. In a vehicle passenger compartment, a trim panel covering an air bag assembly, comprising:

a low-pressured molded substrate having a groove and a cut line defining a door,

an outer fabric layer adhered to the substrate, the fabric layer having a peripheral groove overlying the substrate groove and outlining the door, comprising a tear seam line section, the groove being characterized by a weakened fabric section at the bottom thereof extending along a portion thereof overlying the cut line to form the tear seam line, said weakened fabric section comprising a section of at least partial cuts, whereby inflation of the air bag will force the door to fracture the weakened section and swing the door away from the opening to enable deployment of the air bag outwardly of the panel.

34. The trim panel of claim 33, wherein the outer fabric layer is adhered to the substrate when substrate is formed by low pressure molding comprising sequential injection molding.

35. The trim panel of claim 33, wherein the cut line and the section of partial cuts are formed by one of a laser and a knife.

36. The trim panel of claim 33, wherein the fabric layer includes a backing layer.

37. The trim panel of claim 33 where said low pressure molded substrate comprises sequential injection molding.

38. The low pressure molding of claim 37 comprising reaction injection molding, injection molding, injection-compression molding, gas assist injection molding, structural foam molding, gas counter-pressure injection molding, extrusion molding.

39. In a vehicle passenger compartment, a trim panel covering an air bag assembly, comprising:

(a) a substrate having a groove and a cut line defining a door,

(b) an outer fabric layer adhered to the substrate, the fabric layer having a peripheral groove overlying the substrate groove and outlining the door, comprising a tear seam line section, the groove being characterized by a weakened fabric section at the bottom thereof extending along a portion thereof overlying the cut line to form the tear seam line, said weakened fabric section comprising a substantially reduced thickness of fabric, whereby inflation of the air bag will force the door to fracture the weakened section and swing the door away from the opening to enable deployment of the air bag outwardly of the panel.

40. The trim panel of claim 39 wherein the substantially reduced thickness of fabric is formed by the pressing of a hot die into said fabric to cause weakening of the fabric under the die.

41. The trim panel of claim 39, wherein the outer fabric layer is adhered to the substrate by a low pressure molding process comprising sequential injection molding.

42. The trim panel of claim 39, wherein the cut line is formed by one of a laser and a knife.

43. The trim panel of claim 39, wherein the fabric layer includes a backing layer.

44. A method for forming a trim panel for concealing an air bag system, said trim panel having a molded substrate, said substrate having first and second opposing surfaces and a fabric applied to said first surface, the method comprising the steps of:

(a) providing a mold assembly having coacting first and second mold members, the first mold member having a cavity portion disposed thereon and the second mold member having a detail portion disposed thereon, said first and second mold members being interchangeable with each other such that the cavity and core portions cooperatively define an interior cavity of said mold assembly;

said cavity portion having a series of blade members extending therefrom to substantially engage with said core portion when said mold assembly is closed, said blade members disposed in a pattern that at least partially outlines the periphery of said door;

(b) providing a sheet of fabric for application to said trim panel;

(c) placing the fabric sheet between said coacting first and second mold members in alignment with said cavity portion;

(d) engaging said first and second mold members together to form said mold assembly interior cavity;

(e) injecting a plastic material into said interior mold cavity to integrally form said injection molded substrate and said door and urging the sheet of fabric into contact with the surface of the cavity portion including the blade portions extending from the cavity portion; and

(f) removing said trim panel from said mold assembly; and

weakening said fabric in the slots formed by said thin blade members.

45. The method of claim 44 wherein said fabric is weakened by a cut via projecting a knife or laser through said slots formed in said trim panel wherein said cut is either partially through or completely through said fabric.

46. The method of claim 44 further wherein said step of providing a sheet of fabric includes providing a sheet of fabric containing a backing layer.

47. The method of claim 46 wherein said weakening of said fabric includes weakening of said backing layer.

48. The method of claim 47 wherein said weakening of said backing layer comprises cutting either partially or completely through said backing layer.

49. A method for forming a trim panel for concealing an air bag system, said trim panel having a low pressure injection molded substrate, said substrate having first and second opposing surfaces and a fabric applied to said first surface, the method comprising the steps of:

(a) providing a mold assembly having contacting first and second mold members, the first mold member having a cavity portion disposed thereon and the second mold member having a detail portion disposed thereon, said first and second mold members being interchangeable with each other such that the cavity and core portions cooperatively define an interior cavity of said mold assembly;

(b) providing a sheet of fabric for application to said trim panel;

(c) placing the fabric sheet between said contacting first and second mold members in alignment with said cavity portion;

(d) engaging said first and second mold members together to form said mold assembly interior cavity;

(e) injecting a plastic material into said interior mold cavity to integrally form said low pressure injection molded substrate and said door and urging the sheet of fabric into contact with the surface of the cavity portion; and

(f) removing said trim panel from said mold assembly; and

weakening any one of said fabric sheet or said substrate.

50. The air bag cover of claim 49, wherein at least one of said fabric outer layer or said substrate are weakened in by the application of a knife or a laser and at least partially cutting through any one of said fabric outer layer or said substrate.

51. The trim panel of claim 49 further including wherein the fabric sheet includes a backing layer.

52. The trim panel of claim 51, wherein at least one of said fabric sheet, said backing layer or said substrate are weakened in by the application of a knife or a laser and at least partially cutting through any one of said fabric outer layer, said backing layer or said substrate.

53. The trim panel of claim 49 wherein said substrate formed by low pressure molding comprises the use of sequential injection molding.

54. The trim panel of claim 53 formed by reaction injection molding, injection molding, injection-compression molding, gas assist injection molding, structural foam molding, gas counter-pressure injection molding, extrusion molding.

55. A woven fabric sheeting for use as an air bag cover outer layer, said sheeting being formed by first and second warp yarn and a first and second filled yarn, wherein said first warp yarn and said first fill yarn each comprise a first tensile strength and wherein said second warp yarn and second fill yarn each comprise a second tensile strength, said second tensile strength is less than said first tensile strength, said sheeting being characterized by said second yarns being woven in a pattern in both the warp and fill directions to define a band or bands of weakness in the sheet, said bands of weakness corresponding to the shape of an air bag door.

56. The woven sheeting of claim 55 wherein the second yarn is woven in either the warp or fill direction.

59. The woven sheeting of claim 55 wherein the second tensile strength of said second yarn of said warp or fill yarn is formed by submitting the first yarn to any one of heat, light, a caustic solution and a laser to reduce its tensile strength.

60. The woven sheeting of claim 55 wherein the second tensile strength of said second yarn of said warp or fill yarn is formed by providing said first yarn of said warp or fill with a molecular weight and reducing the molecular weight of said first yarn to provide said second yarn of reduced tensile strength.

61. The woven sheeting of claim 55 wherein the second tensile strength of said second yarn of said warp or fill yarn is formed by providing said first yarn of said warp or fill comprising polymer material with a degree of orientation and adjusting the degree of orientation to provide said second fiber of said second tensile strength.

57. A woven fabric sheeting for use as an air bag cover outer layer, said sheeting being formed by first and second warp yarn and a first and second filled yarn, wherein said first warp yarn and said first fill yarn each comprise a first tensile strength and wherein said second warp yarn and second fill yarn each comprise a second tensile strength, said second tensile strength is greater than said first tensile strength, said sheeting being characterized by said second yarns being woven in a pattern in both the warp and fill directions to define a band or bands of weakness in the sheet, said bands of weakness corresponding to the shape of an air bag door.

58. The woven sheeting of claim 57 wherein the second yarn is woven in either the warp or fill direction

62. The woven sheeting of claim 57 wherein the second tensile strength of said second yarn of said warp or fill yarn is formed by providing said first yarn of said warp or fill comprising polymer material with a degree of orientation and adjusting the degree of orientation to provide said second fiber of said second tensile strength.

63. The woven sheeting of claim 57 wherein the second tensile strength of said second yarn of said warp or fill yarn is formed by providing said first yarn of said warp or fill comprising polymer material with an average molecular weight and adjusting the average molecular weight to provide said second fiber of said second tensile strength.

64. A knitted fabric sheeting for use as an air bag cover outer layer, said sheeting being formed by first and second warp yarn and a first and second weft yarn, wherein said first warp yarn and said first weft yarn each comprise a first tensile strength and wherein said second warp yarn and second weft yarn each comprise a second tensile strength, said second tensile strength is less than said first tensile strength, said sheeting being characterized by said second yarns being woven in a pattern in both the warp and weft directions to define a band or bands of weakness in the sheet, said bands of weakness corresponding to the shape of an air bag door.

65. The knitted fabric sheeting of claim 64 wherein the second yarn is knitted in either the warp or weft direction.

66. The knitted fabric sheeting of claim 64 wherein the second yarn is formed by submitting the first yarn having a first tensile strength to any one of heat, light, a caustic solution and a laser to reduce its tensile strength.

67. The knitted fabric sheeting of claim 64 wherein the second tensile strength of said second yarn of said warp or weft yarn is formed by providing said first yarn of said warp or weft comprising polymer material with a degree of orientation and adjusting the degree of orientation to provide said second fiber of said second tensile strength.

68. The knitted fabric sheeting of claim 64 wherein the second tensile strength of said second yarn of said warp or weft yarn is formed by providing said first yarn of said warp or weft comprising polymer material with a selected average molecular weight and adjusting the average molecular weight to provide said second fiber of said second tensile strength.

69. A knitted fabric sheeting for use as an air bag cover outer layer, said sheeting being formed by first and second warp yarn and a first and second weft yarn, wherein said first warp yarn and said first weft yarn each comprise a first tensile strength and wherein said second warp yarn and second weft yarn each comprise a second tensile strength, said second tensile strength is greater than said first tensile strength, said sheeting being characterized by said second yarns being woven in a pattern in both the warp and weft directions to define a band or bands of weakness in the sheet, said bands of weakness corresponding to the shape of an air bag door.

70. The knitted fabric sheeting of claim 69 wherein the second yarn is knitted in either the warp or weft direction.

71. The knitted fabric sheeting of claim 69 wherein the second tensile strength of said second yarn of said warp or weft yarn is formed by providing said first yarn of said warp or weft comprising polymer material with a degree of orientation and adjusting the degree of orientation to provide said second fiber of said second tensile strength.

72. The knitted fabric sheeting of claim 69 wherein the second tensile strength of said second yarn of said warp or weft yarn is formed by providing said first yarn of said warp or weft comprising polymer material with a selected average molecular weight and adjusting the average molecular weight to provide said second fiber of said second tensile strength.

73. A method for manufacturing an air bag cover for an air bag safety system for a vehicle comprising:

supplying a cover layer having a front side and a backside, wherein said cover layer is selected from the group consisting of fabric, leather or polymeric film material;

supplying a substrate containing an air bag door location that includes a periphery;

weakening said cover layer with a laser at a location that will be adjacent or which will overlie said periphery wherein said weakening does not comprise a physical alteration of said outer layer;

placing said weakened cover layer on said substrate with said cover layer backside in contact with said substrate and wherein said weakening of said cover layer is positioned such that it will be either adjacent or overlying of said periphery of said air bag door location.

74. The method of claim 73 wherein said weakening of said cover layer comprises weakening in a dot pattern, or in a horizontal line pattern, or in a vertical line pattern, and mixtures thereof.

75. The method of claim 73 wherein said cover layer has a thickness, and weakening which does not comprise a physical alteration of said cover layer comprises a weakening wherein the thickness of the cover layer is substantially unchanged by said weakening.

76. The method of claim 73, wherein said cover layer is weakened on said backside.

77. An air bag cover for an air bag safety system for a vehicle comprising:

a fabric outer layer having a front side and a backside, and comprising a weakened portion and an non-weakened portion;

a substrate containing an opening for an airbag door, said opening having a periphery, the substrate formed by low pressure molding;

wherein the fabric outer layer overlies the opening in the substrate, and wherein said non-weakened portion of said fabric layer overlies a portion of said periphery and said weakened portion overlies another portion of said periphery.

78. The air bag cover of claim 77, wherein said opening in said substrate is closed by a door formed integrally with said substrate, said door having an outer edge and a hinge region and wherein said non-weakened fabric outer layer overlies said hinge region.

79. The air bag cover of claim 78, wherein said substrate is provided with a weakening groove along said periphery of said opening and said weakening groove defines at least a portion of said outer edge of said door.

80. The air bag cover of claim 77, wherein said weakened portion of said fabric layer is weakened by partially cutting into said fabric layer.

81. The air bag cover of claim 77, wherein said weakened portion of said fabric layer is weakened by degrading the fabric layer.

82. The air bag cover of claim 77, wherein said weakened portion of said fabric layer is weakened by providing said fabric layer comprising lower strength fibers at the weakened portion.

83. An air bag cover for an air bag safety system for a vehicle comprising:

a fabric outer layer having a front side and a backside, and comprising a reinforced portion and non-reinforced portion;

a substrate containing an opening, said opening having a periphery, the substrate formed by low pressure molding;

wherein the fabric outer layer overlies the opening in the substrate, and wherein said reinforced portion of said fabric layer overlies a portion of said periphery.

84. The air bag cover of claim 83, wherein said opening in said substrate is closed by a door formed integrally with said substrate said door having a hinge region and a periphery, and wherein said reinforced portion of said fabric layer overlies said hinge region.

85. The air bag cover of claim 83, wherein said reinforced portion of said fabric layer comprises fibers having a higher strength than said fibers forming said non-reinforced portion.

86. The air bag cover of claim 85, wherein said higher strength fibers comprise aramid fiber.

87. The air bag cover of claim 85, wherein said higher strength fiber are woven into said fabric layer.

88. The air bag cover of claim 83, wherein said non-reinforced portion of said fabric layer comprises a weakened portion that overlies a portion of said periphery.

89. The air bag cover of claim 84, wherein said weakened portion overlies said periphery of said door.