Abstract: In a webbing retractor, when a vehicle is in an emergency, a pretensioner mechanism supplies gas in a cylinder. A slider substantially closes a gas passing portion, and a piston thereby starts to move upward. A fitting portion pushes the slider upward so as to maintain the closure of the gas passing portion, and a webbing is taken up. When an energy absorbing member in a force limiter mechanism is deformed such that the webbing is pulled out, the piston is moved downward, the gas passing portion is opened by the slider so as to discharge the gas in the cylinder from the gas passing portion.

Abstract: The belt retractor has a belt spool (12) mounted rotatably in a frame (10) and a drive motor (28) coupled to the belt spool (12) via a belt drive (14, 24, 22). This drive motor (28) is a brushless direct current motor with an internal rotor that has a starting torque of at least 2 Nm.

Abstract: A belt retractor for a vehicle safety belt comprises a frame, a belt reel rotatably mounted in the frame, a belt reel axle with an external toothing, and a pawl. The belt retractor has a sliding clutch by means of which the pawl can be brought to engage in the external toothing, in order to rotate the belt reel.

Abstract: A seat belt spooling device having a ball type pretensioner. The pretensioner includes a case and a ball-receiving member formed integrally with each other. The ball receiving member includes a guide formed integrally with the ball-receiving member. The guide is positioned to guide balls entering into the ball-receiving member from the case, thereby reducing the number of components and the assembling cost.

Abstract: A pretensioner 10 for a seat belt 12 employs a strap 30 fixed about a pulley 34 and also fixed at an opposite end 36 to a housing 18. Upon pretensioner activation, an actuator 20 is propelled across a rectangular passage 72 thereby impelling a portion 31 of the strap 30 extending across the passage 72. Torque created by the strap 30 about the pulley 34 effects slideable and rotary engagement of the geared pulley 34 with a geared hub 38. The geared hub 38 co-axially and rotatably communicates with a seat belt retractor spool 46 wherein a seat belt retractor spool shaft 40 axially extends through hub 38 and spool 46. Activation of the pretensioner 10 therefore results in ignition of a gas generant 22 that produces sufficient gas pressure to drive the actuator 20, thereby effecting rotary movement in the pulley 34, the hub 38, the shaft 40, and the spool 46. A seat belt 12 wound about the spool 46 is thereby pretensioned.

Abstract: A pretensioner having a plurality of force transmitting members contained in a tube. One of the force transmitting members is configured to be difficult to deform, to thereby provide for smooth movement of the force transmitting members. A piston receives gas pressure from a gas generator. When gas is released by the gas generator the piston deforms and wedges into a space between the outer peripheral surface of the adjacent force transmitting member and the inner peripheral surface of the tube. Then, the barrel-like force transmitting member presses the piston backward due to force produced by the withdrawing of a seat belt due to the operation of EA. The force transmitting members and the piston can smoothly move because the wedging amount of the piston into the space between the tube wall and the force transmitting member is small.

Abstract: A pretensioner comprises a pyrotechnic force generating device including a horizontal tube with a propellent charged cartridge, a housing receiving one end of the cylinder with the horizontal tube being supported to cooperate with the force generating device in order to reverse-rotate the reel; a force transmitting portion including an arm positioned in a first chamber of the housing, one end of which is directed to the piston in the cylinder and the other end of which is extended out of the cylinder, a pulley rotatably mounted on the other branched end of the arm and a cable fixed at one end to the housing, passed through the pulley, wound around the clutch disk and fixed at the other end to the clutch disk; and a pretensioner positioned in a second chamber, which comprises the clutch disk and a clutch portion, in which the clutch disk includes a circular groove formed around the periphery thereof to allow a length of the cable to be wound thereon, a plurality of second coupling projections each having a rig

Abstract: A pretensioner 10 for a seat belt 12 employs a strap 30 fixed about a pulley 34 and also fixed at an opposite end 36 to a housing 18. Upon pretensioner activation, an actuator 20 is propelled across a rectangular passage 72 thereby impelling a portion 31 of the strap 30 extending across the passage 72. Torque created by the strap 30 about the pulley 34 effects rotary advancement of the geared pulley 34 with a geared clutch 37 engaged therewith. The geared clutch 37 co-axially and rotatably communicates with a seat belt retractor spool 46 wherein a seat belt retractor spool shaft 40 axially extends through the clutch 37 and spool 46. Activation of the pretensioner 10 therefore results in ignition of a gas generant 16 that produces sufficient gas pressure to drive the actuator 20 through a linear passage 72, thereby effecting rotary movement of the pulley 34, the clutch 37, the shaft 40, and the spool 46. A seat belt 12 wound about the spool 46 is thereby pretensioned.

Abstract: Disclosed is a seat belt pretensioner for a vehicle wherein a spool is mounted in such a way that it cannot be further released at the onset of a car accident but can push itself downwardly in a fixed state along the length-wise direction of a retractor and thus can effectively rewind a seat belt with ease. To serve this purpose the seat belt pretensioner of the present invention comprises a retractor cover wherein sliding guides are mounted both on right and left sides, a spool mounted in such a manner that a seat belt is wound up with an elastic support and is able to slide along the sliding guide, and a piston structure, being mounted on the upper part of said cover, pushes said spool downwardly by the explosion force of explosives.

Abstract: A seat belt retractor is formed of a reel for winding a seat belt, and a spring member connected to the reel for providing a retracting force thereto. The retracting force is weak not to provide a feeling of oppression to a passenger when the passenger has fastened the seat belt. A motor is connected to the reel for driving the reel only in a direction of retracting the seat belt to generate a retracting force greater than that of the spring member. Thus, the seat belt retractor retracts the seat belt by sufficiently great retracting force, but does not provide a feeling of oppression to the person when properly fastened.

Abstract: A seat belt retractor has a two-piece belt reel rotatably mounted on a seat belt retractor frame. The two pieces of the belt reel are a spool and a spool insert. A tightening drive creates a torque. A force transmission device transmits torque to the belt reel for winding the belt webbing onto the spool. A load limiter connects the spool and spool insert for to limit force on a seat belt-wearing vehicle occupant during the accelerated forward displacement of the seat belt-wearing vehicle occupant. During effective force limitation, when exceeding a preselected force threshold resulting from the belt force limitation effect and the torque of the tightening drive, in the force transmission device the torque transmission from the tightening drive to the belt reel is interrupted.

Abstract: A drive for a belt tensioner for safety belts has a drive chamber formed between two plates. A drive band whose two ends are fastened to a drive shaft such that the drive band forms a loop which can be exposed to expanding gas discharged from a gas outlet such that the drive band winds off and drives the drive shaft. The drive band is fixed to the plates by a fixing apparatus at a position disposed between its ends.

Abstract: A pretensioner 10 for a seat belt 12 utilizes a perforated strap 34 loosely coiled about a hub 38 wherein the hub 38 is, in normal operation of a vehicle, rotatable with a webbing reel shaft 40. A plurality of protrusions 42 are circumferentially spaced about the hub and mesh with the perforated strap 34 upon activation of the pretensioner 10. The pretensioner 10 contains a first passage 44 and a second passage 46 for the respective containment of the hub 38 and an actuator 20, wherein each passage is formed perpendicular and in volumetric intersection with the other. The pretensioner 10 also contains a gas generant composition 22 in combustive communication with the actuator 20.

Abstract: A seat belt device has a gas generator for generating a high pressure gas when the vehicle is in emergency, a cylinder for conducting the high pressure gas from the gas generator, a piston received movably within the cylinder and pressed and moved by the high pressure gas, and a drive unit for rotating a winding shaft of a seat belt retractor in a direction of removing the slack of a belt, using the movement of the piston, wherein the pretensioner is employed with the energy absorbing mechanism, for reversely rotating the winding shaft if a tension acting on the belt exceeds a predetermined value after removing the slack of the belt.

Abstract: There is provided a pretensioner which can as a whole be made smaller. A rack and pinion type pretensioner is disposed outside a second leg plate of a webbing take-up device. A driving mechanism of the pretensioner includes, as principal components, a piston formed as a rack bar, and a pinion. The pinion includes a toothed portion and a clutch portion, and is directly connected to a winding shaft. Accordingly, as compared with a conventional system in which intermediate gears are disposed between the pinion and the rack bar, the pretensioner can as a whole be made smaller both in radial and axial directions thereof.

Abstract: An apparatus (10) for providing fluid under pressure for actuating a vehicle occupant protection device comprises an electrically actuatable initiator (80) having terminal pins (100). A hermetically sealed metal propellant container (130) contains a propellant (82) ignitable by the initiator (80) to produce fluid under pressure. The propellant container (130) is secured to the initiator (80) by crimping. The apparatus (10) also comprises a member (86) electrically insulating between the metal propellant container (130) and the terminal pins (100) of the initiator (80) to isolate the initiator electrically from the propellant container.

Abstract: A device for activating a seat belt pretensioner comprising a piston that can be driven by a propellant gas in a tubular piston guide. A pressure chamber, in which the propellant gas acts upon the piston and a weak point provided in an opening in a wall of the piston, which ruptures under excess working pressure in the pressure chamber. The weak point is a plastic deformable membrane, which is deformed into a dome shape under excess pressure in the pressure chamber and ruptures in the region of the dome-shaped deformation. The seat belt pretensioner has a belt reel associated with blocking teeth, and a blocking pawl. The time required for the membrane to be deformed and rupture is sufficient for the blocking pawl to securely engage the blocking teeth thereby blocking the belt reel against rotation in a direction of belt extraction.

Abstract: A seat belt retractor has a retractor frame, a belt spool rotatably mounted in the frame, an electric drive motor, a reduction belt gear with a toothed belt connecting the electric motor permanently with the belt spool, and a winding spring functionally arranged between the frame and the belt spool, permanently biasing the belt spool with a winding moment. The electric motor is controlled to either counteract or assist the winding spring.

Abstract: The present invention provides a seat belt system comprising: a moving element (36) rotatably received in a housing (26); a device (32) for applying a pressurized gas to the moving element (36) when abrupt deceleration occurs on a vehicle; a tensile member (40) responsive to movement of the moving element (36) extruded due to the pressurized gas to generate a rotational torque; and a clutch mechanism (44) for transmitting the rotational torque generated by the tensile member (40) to a retractor shaft (24) to rotate the shaft (24) in a webbing-winding direction.

Abstract: A coupling mechanism, in particular for connecting a belt tensioner drive with a belt spool of a belt retractor for a vehicle safety belt, comprises a driving part, an intermediate part, a driven part, a form-fitting coupling and a force-fitting coupling. The form-fitting coupling and the force-fitting coupling are connected in series. The coupling mechanism has an initial state in which the form-fitting coupling is engaged and the force-fitting coupling is disengaged.

Abstract: The invention relates to a drive unit for a safety belt tensioner which has a drive which can be triggered on the response of an acceleration sensor and which can be rotationally fixedly coupled to the belt winding reel. The drive is located in a drive chamber which is formed by two plates, which extend parallel to one another and which are provided with a coating material, and which has a drive band of which at least one end is fastened to a drive shaft.

Abstract: In a pretensioner, an axial direction of a generator accommodating portion is inclined from a direction which is orthogonal to an axial direction of the cylinder main body toward the cylinder main body. As a result, another axial direction end portion of the generator accommodating portion is positioned closer to the cylinder main body side and the dimensions of the pretensioner along the orthogonal axial direction of the cylinder main body becomes small. In addition, at a bottom portion side of the cylinder main body, an open space is generated along the orthogonal direction of the cylinder main body and therefore the pretensioner becomes more compact. Moreover, since the generator accommodating portion and the cylinder main body are connected such that a center axis of the generator accommodating portion is skewed with respect to the center axis of the cylinder main body, a large area can be secured for the opening into the cylinder main body while a compact structure is maintained.

Abstract: A seatbelt pretensioner (10, 210, 310) with a soft-start piston actuator (50) is provided. The pretensioner (10, 210, 310) cooperates with a webbing reel shaft (112, 212, 312) of a seatbelt retractor webbing reel (not shown). The pretensioner (10, 210, 310) includes a housing (16, 216, 316) with at least one passage, and preferably two volumetrically intersecting perpendicular passages (18, 218, 318; 20, 220, 320). A clutch assembly (30, 230, 330) is fixed within the first passage (18, 218, 318), and a webbing reel shaft (12, 212, 312) extends axially through the clutch assembly (30, 230, 330). A soft-start piston actuator (50) with at least a first pressure surface (54) and a second pressure surface (56) is positioned in the second passage (20, 220, 320), and is actuatable with a gas generant composition (60, 260) that produces pressurized gas upon signaling from a remote sensor (not shown).

Abstract: To provide a pre-tensioner which can effectively use ignition pressure of a gas generator and can be constructed in a compact form as a whole and have lighter weight, a pre-tensioner 10 is mounted outside of a side wall 50 of the frame 2 by a base 41. A hexagonal head portion 4d of a reel 4 penetrates a base 41. Fixed to the outer periphery of the hexagonal head portion 4d is a pinion 23. The pinion 23 is provided with external teeth 24 uniformly formed around the periphery thereof. A ring gear 30 is disposed to surround the pinion 23. The ring gear 30 has internal teeth 31 engageable with the external teeth 24 of the pinion 23. The ring gear 30 has levers 32, 33 projecting outwardly, which are formed on the outer periphery of the ring gear 30 at predetermined interval. The lever 32 of the ring gear 30 is substantially in contact with the head ball 20-15 within the pipe 21.

Abstract: A pretensioner 10 for a seat belt 12 utilizes a strap 34 coiled about a clutch assembly 46 wherein the clutch assembly 46 is in normal operation of a vehicle, rotatable about a portion of a webbing reel shaft 16. The pretensioner 10 contains a first passage 20 and a second passage 22 for the respective containment of the clutch assembly 46 and an actuator 32, wherein each passage is formed perpendicular and in volumetric intersection with the other. The pretensioner 10 also contains a gas generant composition 30 in combustive communication with the actuator 32. Upon ignition, the gas pressure produced by the pyrotechnic 30 propels the actuator 32 into the strap 34, thereby effecting rotary advancement of the clutch assembly 46 and the shaft 16, and thus pretensioning the seat belt 12 wound about a spool 13 of a seat belt retractor 14, wherein the spool 13 is rotatably engaged with a second portion of the shaft 16 and thus provided in coaxial relation with the clutch assembly 46.

Abstract: A pretensioner (50) tensions vehicle seat belt webbing (18). The pretensioner (50) has a member (52) movable by an actuating fluid to tension the seat belt webbing (18). The pretensioner (50) further has at least one microelectromechanical system (MEMS) device (120) energizable to supply actuating fluid to move the member (52).

Abstract: An assembly unit consisting of a belt retractor (12) for a vehicle seat belt (16) wound on a belt reel (14) of the belt retractor (12), a belt tensioner drive (10) providing a drive energy by means of which the belt reel (14) of the belt retractor (12) can be driven in the winding direction, and a gearing (20, 24; 30, 36) coupling the belt tensioner drive to the belt reel is characterized in that the gearing (20, 24; 30, 36) provides a translation ratio which changes during a tensioning action.

Abstract: A pretensioner 10 for a seat belt 12 employs a strap 30 fixed about a pulley 34 and also fixed at an opposite end 36 to a housing 18. Upon pretensioner activation, an actuator 20 is propelled across a rectangular passage 72 thereby impelling a portion 31 of the strap 30 extending across the passage 72. Torque created by the strap 30 about the pulley 34 effects rotary advancement of the geared pulley 34 with a geared clutch 37 engaged therewith. The geared clutch 37 co-axially and rotatably communicates with a seat belt retractor spool 46 wherein a seat belt retractor spool shaft 40 axially extends through the clutch 37 and spool 46. Activation of the pretensioner 10 therefore results in ignition of a gas generant 16 that produces sufficient gas pressure to drive the actuator 20 through a linear passage 72, thereby effecting rotary movement of the pulley 34, the clutch 37, the shaft 40, and the spool 46. A seat belt 12 wound about the spool 46 is thereby pretensioned.

Abstract: The invention relates to a safety belt apparatus, in particular for motor vehicles, comprising a safety belt (11) which is connected on the one hand via a belt lock (12) to the vehicle body (13) and on the other hand to a belt winder (14) which is attached to the vehicle body (13), and which has a belt roller (15) which is rotatable about a transverse axis (16) and onto which the belt (11) is wound up to a greater or lesser extent, which is stressed by a spring mechanism (17) in the belt roll-up direction and is connected to a belt tautener (18) as well as to an unwind blocking apparatus (19) which blocks the further drawing out of the belt in the attempt of a rapid belt drawing out and/or in accident caused accelerations at the latest after a limited further rotation of the belt roller (15), with a coupling (20) consisting of an input part (22), an output part (24) and coupling members (25) which are active between them being placed between the belt tautener (18) and the belt roller (15), which coupling (20)

Abstract: A pretensioner 10 for a seat belt 12 employs a strap 30 fixed about a pulley 34 and also fixed at an opposite end 36 to a housing 18. Upon pretensioner activation, an actuator 20 is propelled across a rectangular passage 72 thereby impelling a portion 31 of the strap 30 extending across the passage 72. Torque created by the strap 30 about the pulley 34 effects slideable and rotary engagement of the geared pulley 34 with a geared hub 38. The geared hub 38 co-axially and rotatably communicates with a seat belt retractor spool 46 wherein a seat belt retractor spool shaft 40 axially extends through hub 38 and spool 46. Activation of the pretensioner 10 therefore results in ignition of a gas generant 22 that produces sufficient gas pressure to drive the actuator 20, thereby effecting rotary movement in the pulley 34, the hub 38, the shaft 40, and the spool 46. A seat belt 12 wound about the spool 46 is thereby pretensioned.

Abstract: A pretensioner having a pipe containing a plurality of balls which are applied with lubrication coating. A clearance for passage of the balls at a distal end of the pipe is determined by the inner diameter of the pipe, the root circle diameter of the external teeth of the ring gear, and the position of a spool coupled to a pinion. The space for allowing the balls to pass is defined by the inner surface of a straight portion of the pipe and contact portions of the external teeth of the ring gear with the balls. The clearance is set so that the width of the space is smaller than the diameter of the balls.

Abstract: A seat belt retractor has a belt reel that is rotatably mounted on a frame and on which a seat belt can be wound and unwound. A motive spring biases the belt reel in the winding direction. An electric motor adjusts the spring force of the motive spring can be adjusted and/or a torque produced for tightening the seat belt. The torque can be transmitted to the belt reel by a clutch. The deformation of a deformable spring element brings the clutch into an engaged state. The spring element is held on one end of the spring by a holding device actuated by inertial force, at least for initiating its deformation.

Abstract: A seat belt retractor which achieves more stable performance of a pretensioner is provided. The seat belt retractor includes a spool for winding up a belt thereon. The spool has a shaft portion, a spool gear, and a spring-biased shaft projection which are disposed to project from a face of the spool. A spool bearing (or ring-like collar) is fitted around the shaft portion of the spool. The spool bearing is made of a material having high hardness and high rigidity such as SUS or SC. By this spool bearing, the spool is prevented from being directly subjected to load, like a bearing.

Abstract: A safety belt winding device is provided having a tensioning mechanism with a cable that can be unwound from a pulley, and also having a force-limiting device for a predetermined belt withdrawal, wherein the connection between the belt winding shaft and the tensioning mechanism is adapted to be eliminated after conclusion of the tensioning movement. A retaining element is disposed on an end of the cable and is releasably fixed in position on the pulley, wherein an ejection arm is mounted on the pulley such that it can be pivoted out radially and that during a tensioning process in a belt winding direction is held in a pivoted-in position by the housing in which the pulley is accommodated. During rotation of the belt winding shaft in the belt withdrawal direction, the ejection arm pivots outwardly and is fixed from further rotation via a configuration of the housing and thereby displaces the retainer element of the cable out of engagement with the housing.

Abstract: A coupling between the rotor (16) of a belt tensioner rotary drive and a drive shaft (22) comprises an externally toothed coupling wheel (24) connected to the drive shaft (22) and at least one coupling pawl (32) arranged on the rotor (16). The coupling pawl (32) is movable between a resting position in which it is spaced away from the periphery of the coupling wheel and an engaging position in which it engages the coupling wheel. The coupling pawl (32) is toggle-mounted on a knife-edge bearing on the rotor (16).

Abstract: An inexpensive webbing retractor is obtained by making a pretensioner and a lock device small and reducing the number of parts. A plurality of protrusions are formed on an inner peripheral portion of the bearing body, which pivotally supports a clutch portion. These protrusions are brought into linear contact with an outer peripheral portion of the clutch portion, whereby the bearing body pivotally supports the clutch portion indirectly via the protrusions. Since the protrusions are brought into linear contact with the clutch portion, the contact area becomes quite small. Hence, the protrusions are easily plastically deformed due to friction resistance with the clutch portion. Therefore, resistance that obstructs the rotation of the clutch portion becomes small, and gas pressure can be efficiently supplied for the rotation of a take-up shaft.

Abstract: A seat belt spooling device having a ball type pretensioner. The pretensioner includes a case and a ball-receiving member formed integrally with each other. The ball receiving member includes a guide formed integrally with the ball-receiving member. The guide is positioned to guide balls entering into the ball-receiving member from the case, thereby reducing the number of components and the assembling cost.

Abstract: A seat belt retractor having a structure preventing a gear or pinion having external teeth from being improperly assembled to a spool gear. The pinion includes concave portions on its inner periphery and the spool gear includes corresponding convex portions on its outer periphery. The concave and convex portions are configured to be fit together may be inclined in the circumferential direction and thus have no symmetrical plane. If during assembly the pinion is positioned adjacent the spool gear with the wrong side out, the pinion and the spool gear would not fit together and the mistake would be noticed and, therefore, prevented.

Abstract: A seat belt retractor has a belt reel that is mounted rotatably on a frame. A motive spring biases the belt reel in a winding direction. An electrical driving device adjusts the spring force of the motive spring. A clutch located between the electrical driving device and the belt reel transmits torque produced by the electrical driving device to the belt reel. The clutch has a spring that can be deformed by torque and, when deformed, brings the clutch into an engaged state.

Abstract: A gear mechanism and webbing retractor having a compact size in which a pinion is prevented from being damaged when a large initial driving force is applied from a gear. When a sensor detects an emergent deceleration of a vehicle, a piston driving device is actuated so as to move a rack at its standby position in a direction to a pinion. When the rack is located at the standby position, a tooth face on a side near a front end, of a front end tooth thereof is in contact with a pressure receiving surface of the initially driving member. The rack is moved along a pitch line in the direction to the pinion so that the front end tooth presses the pressure receiving surface. As a result, the initially driving member converts the initial driving force from the rack to a rotation force thereby rotating the pinion in the taking-up direction.

Abstract: In a pretensioner for a webbing retractor, an upper wall portion of a sealing member extends arcuately around an external periphery of a seal holding portion which is formed integrally with a bottom surface of a piston, and the sealing member includes a side wall portion proximate an inner wall of a cylinder. The sealing member is formed from an elastic material, and may be annular or a ring with an angle of 360 degrees or more. In an emergency state of a vehicle, when the piston is moved by gas pressure, the sealing member is pressed against the bottom surface of the piston by gas pressure, and a diameter of the sealing member is increased. Accordingly, the sealing member provides sealing between the piston and the inner wall of the cylinder.

Abstract: In a webbing retractor having a pretensioner mechanism and a force limiter mechanism, when a drive member is rotated in one direction by the pretensioner mechanism, a cam plate is disposed at a sleeve side by an inner peripheral surface of a clutch ring. Thus, a roller engages with a sleeve, the sleeve is rotated integrally with the drive member, and a webbing is taken-up. When the sleeve is rotated in another direction by the force limiter mechanism, the cam plate is inserted into a recess portion of the clutch ring, and the cam plate is disposed at a side opposite to a sleeve side. Thus, rotation of the sleeve with respect to the drive member is permitted, and impeding of the pulling-out of the webbing can be prevented. Accordingly, a force limiter load can be determined by only a load required for deforming an energy absorbing member.

Abstract: A seat belt device with a pretensioner which effectively transmits gas pressure to a ring gear in order to provide a large pretensioning force is provided. A piston is pushed by the pressure of gas provided by a gas generator. The force on the piston is transmitted to balls and the front-most ball exerts force on an external tooth of a ring gear. As a result, pins are sheared so as to release the ring gear. The ring gear moves because the ball exerts force on the ring gear. The internal teeth of the ring gear are meshed with the external teeth of the pinion. The ring gear and the pinion rotate together to pretension a seat belt. Lubricant is applied to the inner surface of the pipe or the outer surfaces of the balls, so that gas pressure can be effectively transmitted to the ring gear.

Abstract: A device for activating a seat belt pretensioner comprising a piston that can be driven by a propellant gas in a tubular piston guide. A pressure chamber, in which the propellant gas acts upon the piston and a weak point provided in an opening in a wall of the piston, which ruptures under excess working pressure in the pressure chamber. The weak point is a plastic deformable membrane, which is deformed into a dome shape under excess pressure in the pressure chamber and ruptures in the region of the dome-shaped deformation. The seat belt pretensioner has a belt reel associated with blocking teeth, and a blocking pawl. The time required for the membrane to be deformed and rupture is sufficient for the blocking pawl to securely engage the blocking teeth thereby blocking the belt reel against rotation in a direction of belt extraction.

Abstract: A belt tensioner comprises a cylinder with an inner shell surface, a piston with a piston head, a working space in the cylinder into which compressed gas enters upon activation of the tensioner to drive the piston, a part engaging the safety belt, and a traction means attached to the piston and to the belt engaging part. The piston head delimits the working space and is formed by an annular sealing plate on which an essentially axially extending thin sealing lip is formed. The lip is adapted to resiliently yield radially and contact the inner shell surface of the cylinder in a biased condition.

Abstract: A webbing winding device having a pre-tensioner for tensioning a webbing for restraining a passenger in a passenger restraining direction in an emergency deceleration of a vehicle, comprising a winding shaft to which an end of the webbing is fixed and a gear train mechanism comprising a plurality of gears arranged in such a manner that adjacent gears mesh with each other, wherein a driving gear which receives an external driving force when the pre-tensioner is actuated is driven from a starting end position to a terminating end, position which are set in advance, so as to rotate the winding shaft in a direction for retracting the webbing, and when a driving of the driving gear is completed, at least a pair of adjacent gears are separated so as to enable the winding shaft to be rotated in the direction for retracting the webbing by inertial force.

Abstract: A seat belt retractor has a pretensioner, which has a cover with integral projections made of aluminum. A pretensioner gear with complementary holes is attached to the cover, with the projections inserted into the holes to immobilize the pretensioner gear. A spool driving gear for driving a spool of the retractor is spaced and disengaged from the pretensioner gear so that the pretensioner gear does not interfere with normal operation of the spool. To tension the seat belt, the pretensioner gear is driven to break the projections to mobilize the pretensioner gear, engage the pretensioner gear with the spool driving gear, and drive the spool driving gear, which rotates the spool and tension the seat belt.

Abstract: A seat belt retractor with a ball type pretensioner including a pipe in which the balls are retained. A front end portion of the pipe is securely retained so that reliable operation of the pretensioner is provided. The pipe does includes a cut-out that does not extend to the front-most end of a pipe. A guide block is fitted in the front-most end of the pipe. The pipe and the guide block are fixed to the plate together by a fastener. The portion where the guide block is fitted to the pipe can provide high rigidity and is thus hardly deformed in every directions. The fastener may be hardened or the material for the fastener may be selected to obtain sufficient strength.

Abstract: A seat belt retractor has a belt reel that is rotatably mounted on a frame and on which a seat belt can be wound and unwound. A motive spring biases the belt reel in the winding direction. An electric motor adjusts the spring force of the motive spring can be adjusted and/or a torque produced for tightening the seat belt. The torque can be transmitted to the belt reel by a clutch. The deformation of a deformable spring element brings the clutch into an engaged state. The spring element is held on one end of the spring by a holding device actuated by inertial force, at least for initiating its deformation.

Abstract: A pretensioner 10 for a seat belt 12 utilizes a strap 34 coiled about a clutch assembly 46 wherein the clutch assembly 46 is in normal operation of a vehicle, rotatable about a portion of a webbing reel shaft 16. The pretensioner 10 contains a first passage 20 and a second passage 22 for the respective containment of the clutch assembly 46 and an actuator 32, wherein each passage is formed perpendicular and in volumetric intersection with the other. The pretensioner 10 also contains a gas generant composition 30 in combustive communication with the actuator 32. Upon ignition, the gas pressure produced by the pyrotechnic 30 propels the actuator 32 into the strap 34, thereby effecting rotary advancement of the clutch assembly 46 and the shaft 16, and thus pretensioning the seat belt 12 wound about a spool 13 of a seat belt retractor 14, wherein the spool 13 is rotatably engaged with a second portion of the shaft 16 and thus provided in coaxial relation with the clutch assembly 46.