Rotary actuator-operated seat belt pretensioner

摘要

A rotary actuator-operated seat belt pretensioner comprises a frame, a belt take-up shaft rotatably mounted on the frame, and a rotary actuator mounted on the frame and including a pressure chamber, a rotating member and a gas generator for supplying pressurized gas to the pressure chamber to impart rotation to the rotating member. A clutch is interposed between the rotating member and the take-up shaft. The pressure chamber of the actuator is annular and includes an inner wall defining a space within the chamber, and the clutch is received in the space within the chamber. The driving force of the rotating member produced by gas pressure supplied to the pressure chamber is transmitted to the take-up shaft by the clutch, and rotation of the take-up shaft winds a segment of the belt onto the shaft and thereby tightens the belt.