Airbag module and seat related thereto, and also manufacturing apparatus and assembly method therefor

An airbag module deployment device for an airbag deployable from under a seat cover having a stitched seam having a length, the device comprising:

• a collar positionable about the airbag, the collar including
• a plurality of tear strips each having a first end extending from the collar, and a second end opposite the first end connectable to the stitched seam to intersect the stitched seam at an angle to an axis defined by the length of the stitched seam, the plurality of tear strips thereby intersecting and connectable to the stitched seam at a plurality of separated locations along the length of the stitched seam, the plurality of tear strips thereby operative to tear the stitched seam to form a plurality of successive holes in the stitched seam when the airbag is deployed;
• a plurality of slits formed in the collar, a plurality of tear strips each passable through one of the plurality of slits in a first direction before a connection is made to the stitched seam, the collar thereby forming a pulley effect to leverage tear strips in a second direction opposite to the first direction when the airbag is deployed and expanded, to thereby pull the tear strips to form the holes in the stitched seam, thereby weakening the stitched seam to admit passage of the airbag past the seat cover when the expanding airbag tears the stitched seam between the successive holes.