Patent ID: 11858450
Assignee: ZF PASSIVE SAFETY SYSTEMS US INC.
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B

Claim 0:
1. A restraint system for helping to protect an occupant of a vehicle having a roof and a cabin with a seat for the occupant, comprising:
an airbag having a pre-deployment condition in which the airbag is deflated and stored in the roof, the airbag being inflatable from the stored condition to a deployed condition extending downward from the roof into the cabin in front of the seat;
first and second retractors mounted in the roof rearward of the seat, the first retractor being positioned on an inboard side of the seat, the second retractor being positioned on an outboard side of the seat;
a first tether having a first end connected to an inboard side of the airbag and a second end connected to the first retractor, and a second tether having a first end connected to an outboard side of the airbag and a second end connected to the second retractor, wherein, in the pre-deployment condition, the first tether is wound onto the first retractor and the second tether is wound onto the second retractor;
a seat weight sensor configured to measure a weight of the occupant on the seat; and
a controller configured to control inflation of the airbag and the operation of the first and second retractors, wherein the controller is operatively connected to the seat weight sensor and is configured to actuate the first and second retractors to release the first and second tethers to unspool from the first and second retractors under tension applied by the inflating airbag in response to airbag deployment and a sensed weight of the occupant determined via the seat weight sensor, to control the first and second retractors to control the unspooling of the first and second tethers to limit the deployed position of the airbag prior to occupant impact with the airbag in response to the sensed weight of the occupant, and to control unspooling of the first and second tethers after occupant impact with the airbag to control occupant ride-down in response to the sensed weight of the occupant.