Seat belt pretensioner
AssigneeTRW Vehicle Safety Systems Inc.
InventorReiner Lenzen
Life of this patent
Estimating the term…
Abstract
A seat belt pretensioner according to the present invention comprises a piston movable by high pressure gas. A flexible cable, responsive to movement of the piston, rotates the take-up spool in a belt retraction direction to pull the belt against the vehicle occupant and eliminate slack in the belt. A linear ignition material for generating a high pressure gas is in fluid communication with the piston to move the piston in response to ignition of said linear ignition material. The linear ignition material comprises a frangible sheath and at least one gas generating pyrotechnic cord disposed within said sheath.
Claims13
A pretensioner for a vehicle seat belt retractor having a rotatable take-up spool on which seat belt webbing is wound, said pretensioner comprising:
- a pressure chamber;
- a drive member movable in said chamber by a high pressure gas;
- means responsive to movement of said drive member for rotating said take-up spool in a belt retraction direction to pull the seat belt webbing against a vehicle occupant and eliminate slack in the seat belt webbing;
- a gas generating means for generating at least a substantial portion of said high pressure gas consisting of an elongated frangible sheath and pyrotechnic material disposed within said sheath, said pyrotechnic material comprising at least one elongated gas generating pyrotechnic cord disposed within said sheath;
- means for igniting said pyrotechnic cord;
- means for holding said frangible sheath so that a high pressure gas is released from said frangible sheath on ignition of the pyrotechnic cord;
- and
- means whereby said high pressure gas is released into said pressure chamber.
A seat belt pretensioner comprising:
- a pressure chamber;
- said pressure chamber comprising an elongated tubular member;
- a piston movable longitudinally in said tubular member under the influence of high pressure gas in said pressure chamber;
- a gas generating means for generating at least a substantial portion of said high pressure gas consisting of an elongated frangible sheath and a plurality of elongated pyrotechnic cords disposed within said frangible sheath;
- means holding said frangible sheath so that a high pressure gas is released from said frangible sheath on the ignition of said pyrotechnic cord;
- means whereby said high pressure gas is released into said pressure chamber to move said piston;
- means for igniting said gas generating means;
- a reel to tighten a seal belt in response to ignition of said gas generating means;
- and
- a flexible cable connected with said piston and said reel for rotating said reel in a belt retraction direction upon movement of said piston is said tubular member.
A pretensioner for a vehicle seat belt retractor having a rotatable take-up spool on which seat belt webbing is wound, said pretensioner comprising:
- a pressure chamber;
- a drive member movable in said chamber by a high pressure gas;
- means responsive to movement of said drive member for rotating said take-up spool in a belt retraction direction to pull the seat belt webbing against a vehicle occupant and eliminate slack in the seat belt webbing;
- a gas generating means for generating said high pressure gas comprising an elongated frangible sheath and at least one elongated gas generating pyrotechnic cord disposed within said sheath;
- means holding one end of said frangible sheath so that a portion of said frangible sheath and said pyrotechnic cord extend into said pressure chamber;
- and
- means for igniting said pyrotechnic cord.
A seat belt pretensioner comprising:
- a pressure chamber;
- a gas generating means comprising an elongated frangible sheath and a plurality of elongated pyrotechnic cords disposed within said frangible sheath;
- means holding one end of said frangible sheath so that a portion of said frangible sheath and said pyrotechnic cords extend into said pressure chamber;
- mean for igniting said gas generating means;
- a reel to tighten a seat belt in response to ignition of said gas generating means;
- said pressure chamber comprising an elongated tubular member;
- a piston movable longitudinally in said tubular member under the influence of high pressure gas in said pressure chamber;
- and
- a flexible cable connected with said piston and said reel for rotating said reel in a belt retraction direction upon movement of said piton in said tubular member.
Dependencies are inferred from the claim text.