Fully extended pleat for passenger air bag fold

• US 5,501,489 A
• Filed: 03/30/1995
• Issued: 03/26/1996
• Est. Priority Date: 03/30/1995
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Paxton, Donald J., Folsom, Marc D.
• Primary Examiner(s): Tyson, Karin L.
• Application Number:
  US08/413,743
• Time in Patent Office: 362 Days
• Field of Search: 280/743.1, 280/743.2, 280/732, 280/731, 280/728.1
• US Class Current: 280/743.1
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/237 characterised by the way they are folded

Abstract

A fully extended pleat for a passenger side air bag cushion employs folds which extend fully across the folded cushion rather than terminating near the center of the folded cushion. A packing advantage of this fold is that there is no free volume or dead space between the pleats thereby reducing the pack size. A performance advantage is that surface friction between the pleats acts to retards somewhat the cushion deployment to reduce hitting and slapping of the occupants in the event of a crash. Finally, a process advantage is that the pleats do not have to be controlled to a specific depth, thereby allowing the folding mechanisms to be concerned only with the final width of the pleats and allowing one less control in the folding operation.

Claims

1. A method of folding an inflatable air bag cushion made of an air bag fabric and having a rectangular mouth that is attached to a cushion housing having an open side that has a length corresponding to the width of the bag mouth comprising the steps, with the cushion initially unfolded and uninflated and positioned with the bag bottom panel (34) facing up, of:

a. positioning the cushion fabric so that it forms a cup shape with the bag mouth (12) held in position at the open side of said housing (22) to locate a first lateral fold line (36) which forms a center portion adapted to face a passenger seating position when said cushion is installed in a vehicle and inflated, said first fold line being located at a predetermined position from said mouth and creating a second lateral fold line (38) in the vicinity of said mouth;

b. forming fully extended pleats from opposite sides on a sequential basis by;

i. tucking one side of unrolled cushion fabric in a first lateral direction to form a first tuck having a first longitudinal fold line (42) positioned to be in substantial alignment with a first end (44) of the housing and extending longitudinally substantially the entire distance between the first and second lateral fold lines (36) and (38);

ii. tucking the other side of the unrolled cushion fabric in a second lateral direction opposite the first lateral direction across an upper panel (46) of the first tuck to form a second tuck having a second fold line (48) positioned to be in substantial alignment with a second end (50) of said cushion housing and extending longitudinally substantially the entire distance between said first and second fold lines (36) and (38);

iii. tucking again the first side of the unrolled cushion fabric in said first lateral direction across an upper panel (52) to form a third longitudinal fold line (54) to be in substantial alignment with said first end of said cushion housing; and

iv. tucking again the second side of the unrolled cushion fabric in said second lateral direction across an upper panel (56) of the last mentioned tuck to form a fourth longitudinal fold line (58) to be in substantial alignment with the second end (50) of the housing;

c. rolling the folded fabric of the cushion toward the mouth of the cushion stopping at a second predetermined position from mouth (12);

d. placing the rolled cushion at the cushion mouth while leaving a loop of excess fabric protruding from the housing;

e. folding the excess fabric over the cushion roll to form an overlap; and

f. applying a protective member that is carried by the housing and presses against the overlap that maintains the folded and rolled cushion in said housing.

2. The method of claim 1 wherein the rolling of the cushion is stopped at a position about 200 mm from the cushion mouth and the diameter of the cushion roll is larger than the width of the cushion mouth.

3. The method of claim 2 wherein the length of said loop is about 95 mm when the cushion roll is placed at the cushion mouth and the fabric overlap is at least about 60 mm.

4. An inflatable folded air bag cushion adapted to be mounted in a vehicle for restraining a vehicle passenger, the air bag being made of a flexible fabric and having a generally rectangular mouth with one pair of sides defining the width of the mouth,

the folded air bag cushion including:

at least two longitudinal pleats defined by first fold lines extending parallel to the width of the mouth and second fold lines spaced from and parallel to the first fold lines, the longitudinal pleats having a length extending perpendicular to both the first and second fold lines;

the at least two longitudinal pleats further including a plurality of transverse pleats defined by third and fourth fold lines perpendicular to the first and second fold lines, the third and fourth fold lines corresponding to width ends of the mouth, the transverse pleats each extending generally the width of the mouth and for the length of the longitudinal pleats;

a roll formed in the transverse pleats having an axis parallel to the width of the mouth in part of the length of the longitudinal pleats, the roll being located adjacent the mouth of the air bag cushion; and

the remainder of the length of the longitudinal pleats being formed into a loop and folded around the roll on an opposite side of the roll from the mouth of the air bag cushion.

5. An inflatable folded and rolled air bag cushion attached to a rigid housing adapted to be mounted in a vehicle for restraining a vehicle passenger, the air bag being made of a flexible fabric and having a generally rectangular mouth with one pair of sides defining the width of the mouth, said mouth width being substantially equal to the length of an opening in said housing,

the folded air bag cushion including:

at least two longitudinal pleats defined by first fold lines extending parallel to and for the extent of the width of the bag mouth and second fold lines spaced from and parallel to the first fold lines, the longitudinal pleats having a length extending perpendicular to both the first and second fold lines;

the at least two longitudinal pleats further including a plurality of transverse pleats defined by third and fourth fold lines perpendicular to the first and second fold lines, the third and fourth fold lines corresponding to the length of the housing opening, the transverse pleats each extending generally the length of the housing opening and for the length of the longitudinal pleats;

a roll formed in the transverse pleats having an axis parallel to the width of the mouth, said roll being formed of only part of the length of the longitudinal pleats and being tightly positioned against the air bag cushion fabric at one side of the mouth of the air bag to provide an exposed portion of the roll which does not extend into the housing opening; and

the remainder of the length of the longitudinal pleats being formed into a loop of unrolled fabric having an end that extends a predetermined distance from an edge of the housing opening, said loop end being folded inwardly toward the roll axis to contact only part of the exposed roll portion.

6. An air bag cushion as defined in claim 5 further having a protective cover secured to edges of said housing which tightly holds the rolled air bag fabric in place against the housing opening.