Vehicle safety device

• US 3,937,488 A
• Filed: 02/22/1974
• Issued: 02/10/1976
• Est. Priority Date: 05/05/1972
• Status: Expired due to Term

• Current Assignee: Irvin Industries Canada Limited
• Original Assignee: Irvin Industries Canada Limited
• Inventors: Palm, Lorenz A., Wilson, Kenneth R. A.
• Primary Examiner(s): Goodman, Philip
• Assistant Examiner(s): Silverstrim, John P.
• Application Number:
  US05/444,637
• Time in Patent Office: 718 Days
• Field of Search: 280/150 AB
• US Class Current: 280/736
• CPC Class Codes: B60R 21/235 characterised by their material

Abstract

A vehicle safety device comprising an inflatable occupant restraint bag which is comprised of at least two different materials, one having a range of permeability to the inflating fluid of the restraint bag which is different from the range of inflating fluid permeability of the other, and wherein the overall inflating fluid permeability of the restraint bag is within a given design range.

Claims

1. A vehicle safety device adapted for attachment to a vehicle for protecting an occupant thereof during an accident, said vehicle safety device including impact bag means inflatable on crash impact by fluid flow thereinto, said impact bag means having a collapsed condition and an expanded operative condition for restraining movement of an occupant relative to the vehicle as the result of a crash impact, said impact bag means comprising in part a material from zero to low permeability with respect to the inflating fluid thereof and in part at least one other material having variable permeability which increases and decreases in relation to the fluid pressures within said impact bag means, certain areas of the bag being reinforced for added strength, and wherein the total flow rate of the inflating fluid through the material of the impact bag is within the range of 1800 <

ε

λ

_i S_i <

2300 cubic feet per minute and wherein the area of the material of variable permeability is determined according to the formula;

##EQU5## wherein;

ε

λ

_i S_i is the desired summation of flow through all pieces of fabric (λ

S for each piece) and

λ

₁ is the weighted average of the permeability of the material of variable permeability,

λ

₂ is the weighted average of the permeability of the material of zero to low permeability,

S₁ is the total of the design area of the material of variable permeability,

S₂ is the total of the design area of material of zero to low permeability,

S₃ is the area made relatively impervious by installation of reinforcing,

S_Tot is the total bag design area,

all values of λ

are in terms of cubic feet per minute per square foot at 1 p.s.i.g,

and all values of S are in terms of square feet.

2. A vehicle safety device as specified in claim 1 wherein ε

λ

_i S_i is substantially 2050 cubic feet per minute at 1 p.s.i.g.

3. A vehicle safety device as specified in claim 1 wherein the upper limit of λ

₂ is substantially sixty-seven cubic feet per minute per square foot at 1 p.s.i.g.

4. A vehicle safety device adapted for attachment to a vehicle for protecting an occupant thereof during an accident, said vehicle safety device including impact bag means inflatable on crash impact by fluid flow thereinto, said impact bag means having a collapsed condition and an expanded operative condition for restraining movement of an occupant relative to the vehicle as a result of a crash impact, said impact bag means comprising in part a materail from zero to low permeability with respect to the inflating fluid thereof and in part another material having variable permeability which increases and decreases in relation to the fluid pressures within said impact bag means, certain areas of the bag being reinforced for added strength, wherein the total flow rate of the inflating fluid through the material of the impact bag is within the range of 1800 <

ε

λ

_i S_i <

2300 cubic feet per minute and wherein the area of the material of variable permeability is determined according to the formula;

##EQU6## wherein;

ε

λ

_i S_i is the desired summation of flow through all pieces of fabric (λ

S for each piece),

λ

₁ is the permeability of the material of variable permeability,

λ

₂ is the permeability of the material of from zero to low permeability,

S₁ is the design area of the material of variable permeability,

S₂ is the design area of the material of from zero to low permeability,

S₃ is the area made relatively impervious by installation of reinforcing,

S_Tot. is the total bag design area,

all values of λ

are in terms of cubic feet per minute per square foot at 1 p.s.i.g.,

and all values of S are in terms of square feet.

5. A vehicle safety device as specified in claim 4 wherein ε

λ

_i S_i is substantially 2050 cubic feet per minute at 1 p.s.i.g.

6. A vehicle safety device as specified in claim 4 wherein the upper limit of λ

₂ is substantially 76 cubic feet per minute per square foot at 1 p.s.i.g.