Abstract: A seat belt system (10) comprises a seat belt (15) and a tongue assembly (22). A buckle (26) engageable with the tongue assembly (22) secures the system (10) in a buckled condition in which the belt (15) is divided into a torso portion (28) and a lap portion (29). The system (10) also includes an inflatable device (100) comprising an inflatable portion (98) of the belt (15). An inflation fluid source (40) provides inflation fluid to the inflatable device (100) only when the tongue assembly (22) is engaged with the buckle (26). A cinch mechanism (130) has a cinched condition resisting movement of the belt (15) through the tongue assembly (22). The inflatable device (100), when inflated, causes the cinch mechanism (130) to move to the released condition and causes the torso portion (28) and the lap portion (29) of the belt (15) to be tensioned about the vehicle occupant.

Abstract: An apparatus (10) includes a crash sensor (49) which senses a crash event and provides a signal (50) indicative of the crash event. A transmitter (54) transmits a signal (58) in response to the crash sensor signal (50). A receiver (60), which is separated from the transmitter (54), receives the transmitter signal (58) and provides a control signal (80) upon receiving the transmitter signal (58). A buckle switch (34) is operable to detect a belted or an unbelted condition of a seat belt system (18). The apparatus (10) also includes an actuatable pretensioner device (49) which actuates to help to protect a vehicle occupant during a crash event. A power switch (82) receives the control signal (80) to connect the pretensioner device (49) electrically with a power source (35, 84) in response to the power switch (82) receiving the control signal (80) while the buckle switch 34 is detecting a belted condition.

Abstract: An apparatus (40) pretensions seat belt webbing (16) which is extensible about an occupant of a vehicle seat (14). The apparatus (40) includes a movable first member (140), a connector (42) for connecting the first member (140) with the seat belt webbing (16), a movable second member (200), a pyrotechnic device (120) for applying a force to the second member (200) to move the second member, and force limiting coupling device (240). The force limiting coupling device (240) couples the first member (140) and the second member (200). The coupling device (240) moves the first member (140) with the second member (200) until a predetermined force is applied by the connector (42) to the first member (140) resisting movement of the first member with the second member. Thereafter, the coupling device (240) enables the second member to move relative to the first member.

Abstract: An apparatus (40) pretensions seat belt webbing (16) which is extensible about an occupant of a vehicle seat (14). The apparatus (40) includes a housing (50) defining a chamber (56), a piston (90) in the chamber (56), and a coupling member (42) for coupling the piston (90) to the seat belt webbing (16). The coupling member (42) transmits force acting on the piston (90) to the seat belt webbing (16). The apparatus (40) further includes a first pyrotechnic device (200) for applying a first force to the piston (90) to move the piston initially in a first direction (B) in the chamber (56) to remove slack in the seat belt webbing (16). A second pyrotechnic device (220) applies a second force to the piston (90) in the first direction (B) to tension the seat belt webbing (16) against the occupant after the slack has been removed from the seat belt webbing (16) by the first force.