Patent attributes
A seat belt pretensioner may include a cylinder, a piston slidably disposed in the cylinder, a gas generator installed to rear end portion of the cylinder and configured to supply a propellant gas to the piston for moving the piston in a forward direction, a first direction conversion unit disposed between the gas generator and the piston and connected to the cylinder, and a coupling member for coupling a seat belt and the piston, wherein a portion of the coupling member is engaged with the first direction conversion unit so as to change a movement direction of the coupling member while the piston moves in the forward direction, and a reward movement restriction member configured to restrict a rearward movement of the piston while the piston moves in the forward direction by the propellant gas of the gas generator.
