Patent ID: 8651517

Claim:
A side curtain air bag system for deploying downward during a crash event from a roofline of a vehicle into a protection zone overlapping an out-of-position head region, wherein the vehicle has a B-pillar at a midpoint of the vehicle, the system comprising: an inflator for discharging an inflation gas upon the occurrence of the crash event; and an inflatable bag including first, second, and third chambers, wherein the second chamber has a respective deployed position coinciding with the out-of-position head region, wherein the first chamber has a respective deployed position between the B-pillar and the deployed position of the second chamber, wherein the third chamber has a respective deployed position along a lateral edge of the inflatable bag so that the second chamber is disposed between the first and third chambers, wherein the inflatable bag includes a gas passage extending along an upper edge for receiving the inflation gas from the inflator, wherein the gas passage is fluidically coupled to the third chamber at an upper end of the third chamber and to the first chamber at an upper end of the first chamber, wherein the first chamber is configured to inflate at a rate slower than a rate at which the third chamber inflates so that the third chamber is substantially full before the first chamber is substantially full, and wherein the chambers are configured so that, in response to the discharge of the inflation gas, at least the third chamber substantially fills prior to expansion of the second chamber, whereby the inflatable bag substantially completes its downward movement prior to full expansion of the second chamber.