| 摘要 |
PURPOSE:To prevent transmission of the drive reaction force of a piston to a frame by forming the piston and cylinder assembly of a seat belt stretching device with a pair of drive members positioned facing each other and movable in a direction in which they are separated away from each other, and hooking a cable to a guide member connected to each drive member. CONSTITUTION:A support plate 2a elevatably inserted in a seat part 3a of a frame 3 secured to a car body B is secured to the lower end of a support lever 2 having elasticity secured to a buckle 1 of a seat belt. A piston and cylinder assembly 11 to tract downward the support plate 2a through a cable 23 is disposed in a flat boxform part 3b of the frame 3. The assembly 11 comprises cylinders 12 secured to the inner central part and both side walls of the boxform part 3b and having both ends which are opened and a pair of front and rear pistons 13 and 14 slidably engaged with the respective cylinders. An expansion chamber 15 is formed between the two pistons 13 and 14. The expansion chamber 15 is communicated to a powder chamber 18 located in a cylinder part 16, protruded from the one side of the cylinder 12, and charged with powder 17 through a through-hole 19. |
