Tightening means for safety belt restraining systems in vehicles

A tightening means for a safety belt restraining system in a vehicle, the restraining system including a first fitting to be anchored to the vehicle body and a second fitting to be connected to a belt portion of the restraining system, said tightening means comprising:

• a pyrotechnic drive including a cylinder block having a cylindrical wall for defining a cylinder bore therein, said cylinder bore having a longitudinal axis;
• a piston slidably received in said cylinder bore and a piston rod connected to said piston;
• said cylinder block being connected to said second fitting and said piston rod being connected to said first fitting;
• a guide plate connected to said first fitting, said cylinder block being slidably mounted on said guide plate;
• a pyrotechnic gas generator;
• a vehicle sensitive trigger mechanism for activating said gas generator;
• and
• an accommodation bore for receiving said gas generator in said cylinder block and communicating with said cylinder bore;
• said gas generator, when activated, producing gas under pressure to move said cylinder block in a first direction with respect to said piston and piston rod, along said guide plate, while said piston and piston rod remain stationary;
• said guide plate having a longitudinal slot extending parallel to the axis of said cylinder bore, a fitting part being secured to said cylinder block by means of a bolt, said bolt having a shank which passes through said longitudinal slot.

A tightening means for a safety belt restraining system in a vehicle, the restraining system including a first fitting to be anchored to the vehicle body and a second fitting to be connected to a belt portion of the restraining system, said tightening means comprising:

• a pyrotechnic drive including a cylinder block having a cylindrical wall for defining a cylinder bore therein, said cylinder bore having a longitudinal axis;
• a piston slidably received in said cylinder bore and a piston rod connected to said piston;
• said cylinder block being connected to said second fitting and said piston rod being connected to said first fitting;
• a guide plate connected to said first fitting, said cylinder block being slidably mounted on said guide plate;
• a pyrotechnic gas generator;
• a vehicle sensitive trigger mechanism for activating said gas generator;
• and
• an accommodation bore for receiving said gas generator in said cylinder block and communicating with said cylinder bore;
• said gas generator, when activated, producing gas under pressure to move said cylinder block in a first direction with respect to said piston and piston rod, along said guide plate, while said piston and piston rod remain stationary;
• said cylinder block comprising a flat plate at least approximately rectangular in plan view and having a first longitudinal edge, said flat plate having said cylinder bore defined therein along said first longitudinal edge, and said cylinder bore having a first piston receiving end which is connected to a gas action passage and a second end which is open to atmosphere;
• said cylinder block having a second longitudinal edge remote from and shorter than said first longitudinal edge, said second longitudinal edge having a groove, formed therein, a guide strip being secured to said guide member and slidably engaged in said groove.

A tightening means for a safety belt restraining system in a vehicle, the restraining system including a first fitting to be anchored to the vehicle body and a second fitting to be connected to a belt portion of the restraining system, said tightening means comprising:

• a pyrotechnic drive including a cylinder block having a cylindrical wall for defining a cylinder bore therein, said cylinder bore having a longitudinal axis;
• a piston slidably received in said cylinder bore and a piston rod connected to said piston;
• said cylinder block being connected to said second fitting and said piston rod being connected to said first fitting;
• a guide plate connected to said first fitting, said cylinder block being slidably mounted on said guide plate;
• a pyrotechnic gas generator;
• a vehicle sensitive trigger mechanism for activating said gas generator;
• and
• an accommodation bore for receiving said gas generator in said cylinder block and communicating with said cylinder bore;
• said gas generator, when activated, producing gas under pressure to move said cylinder block in a first direction with respect to said piston and piston rod, along said guide plate, while said piston and piston rod remain stationary;
• said pyrotechnic drive including two parallel piston/cylinder units which are disposed spaced apart in said cylinder block and which are each operable by said one pyrotechnic gas generator.

A tightening means for a safety belt restraining system in a vehicle, the restraining system including a first fitting to be anchored to the vehicle body and a second fitting to be connected to a belt portion of the restraining system, said tightening means comprising:

• a pyrotechnic drive including a cylinder block having a cylindrical wall for defining a cylinder bore therein, said cylinder bore having a longitudinal axis;
• a piston slidably received in said cylinder bore and a piston rod connected to said piston;
• said cylinder block being connected to said second fitting and said piston rod being connected to said first fitting;
• a guide plate connected to said first fitting, said cylinder block being slidably mounted on said guide plate;
• a pyrotechnic gas generator having an impact fuse;
• a vehicle sensitive trigger mechanism for activating said gas generator;
• and
• an accommodation bore for receiving said gas generator in said cylinder block and communicating with said cylinder bore;
• said gas generator, when activated, producing gas under pressure to move said cylinder block in a first direction with respect to said piston and piston rod, along said guide plate, while said piston and piston rod remain stationary;
• said tightening means further comprising a mechanical firing mechanism operatively connected with said pyrotechnic gas generator, said firing mechanism including:
• a pivotally mounted vehicle sensitive inertia mass;
• a pivotally mounted strike piece and a spring biasing said strike piece into a first position;
• a firing pin having a first end disposed adjacent said impact fuse of said gas generator and a second end disposed adjacent said strike piece;
• and
• a trigger mechanism movable between a first condition in which said trigger mechanism holds said strike piece in its first position spaced from said second end of said firing pin and a second condition in which, upon vehicle sensitive pivoting of said inertia mass after overcoming an inhibition threshold, said trigger mechanism releases said strike piece, said spring then biasing said strike piece into engagement with said second end of said firing pin to move said firing pin to effect firing of said gas generator.

Apparatus for tightening a belt portion of a vehicle safety belt system, the system including a first fitting for connection with the vehicle body and a second fitting for connection with the belt portion of the safety belt system, comprising pyrotechnic drive means for tightening the belt portion, said pyrotechnic drive means comprising:

• a cylinder block fixed to the second fitting and slidably connected with the first fitting, said cylinder block having a cylinder wall defining therein a cylinder chamber having a longitudinal axis;
• a piston slidably received in said cylinder chamber;
• a piston rod fixed to the first fitting and to said piston;
• and
• gas generating means for, when actuated, generating gas to move said cylinder block in a first direction relative to said piston and said piston rod to tighten the belt portion, said piston and said piston rod remaining stationary upon actuation of said gas generating means.