Inflatable bags for airbag passive restraint systems for driver and method for production thereof

摘要

An inflatable bag for airbag passive restraints for driver which comprises upper and lower circular base cloths of the same size seamed together at their outer peripheries and lateral regulating means for regulating inflation of the bag in lateral and upward directions and causing downward inflation, which means extends to link between an inner periphery of the lower base cloth and the outer peripheries in a shorter length than the radial distance therebetween, thus forming a sag portion on the lower cloth. When the bag is deployed, the lateral regulating means enables the sag portion to bulge sideways out of a steering wheel to protect a driver. The bag may further include upward restricting means for upward inflation. The lateral and the upward regulating means may be located in a whole circumferential area or within a range of 1/2 to 1/4 the circumference of both cloths. A method of producing the bag having lateral or both regulating means is characterized by using a third cloth of the same size having strap-like portion or portions defined by communicating hole or holes. After superposing and sewing of the lower, upper and third cloths, the strap-like portions are each raised and folded into two and sewn at two roots, thus forming the lateral means. Then the folded strap-like portions are cut at one root and the unfolded strap ends are sewn to the upper base cloth to form upward strap members.