Patent Application
20120175937
The invention relates to a retractor and a pretensioner for a seat belt.
Seat belts are designed to secure an occupant of a vehicle against unintended movement that may result if the vehicle is involved in a collision or in a sudden stop. A properly worn seat belt is also designed to ensure that the wearer of the belt is in a proper position for protection by a deployable airbag. Seat belts are additionally designed to absorb energy by stretching during sudden deceleration to reduce a speed differential between the passenger's body and the vehicle interior. Vehicle seat belt systems are frequently equipped with pretensioners to preemptively tighten the belt around the wearer during sudden deceleration.
A seat belt system for a vehicle includes a seat frame. The seat belt system also includes a lap belt having a first end and a second end, wherein the first end is connected to a buckle and the second end is connected to an anchor. The seat belt system additionally includes a single retractor-pretensioner operatively connected to the seat frame and configured to simultaneously tension the first end and the second end.
The single retractor-pretensioner may include a spool operatively connected to the first end of the belt via a first cable and to the second end of the belt via a second cable.
The spool may include a first channel and a second channel. In such a case, the first channel may be configured to accept and guide the first cable and the second channel may be configured to accept and guide the second cable.
The seat frame may include a first structure configured to support a seatback and a second structure configured to support a cushion. In such a case, the single retractor-pretensioner may be operatively connected to the second structure and positioned under the cushion. The single retractor-pretensioner may also be operatively connected to the first structure and positioned against the seatback.
The single retractor-pretensioner may be configured to rotate the spool and simultaneously tension the first and second ends of the belt.
The seat belt system may additionally include a sensor positioned on the vehicle and configured to generate a signal in response to a force having a predetermined magnitude. In such a case, the single retractor-pretensioner may be triggered by the signal.
The single retractor-pretensioner may include a pretensioning tube that is operatively connected to the spool. In such a case, the pretensioning tube may house a pyrotechnic that is triggered to simultaneously tension the first and second ends of the belt in response to the signal.
Additionally, the seat belt system may include a controller that is configured to trigger the pyrotechnic in response to the signal.
A vehicle having the disclosed seat belt system is also provided.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings, wherein like reference numbers refer to like components,
The seat belt system 10 is configured to provide a safety restraint for an occupant of the seat 16. The seat belt system 10 includes a shoulder belt 32 and a lap belt 34, wherein the shoulder belt 32 is configured to be worn around the torso of the occupant of the seat 16, and the lap belt 34 is configured to be worn around the occupant's waist. The lap belt 34 includes a first end 36 and a second end 38. The first end 36 is connected to a buckle 40 and the second end 38 is connected to an anchor 42. The seat belt system 10 also includes a single retractor-pretensioner 44. The single retractor-pretensioner 44 is operatively connected to the seat frame 18 and is configured to simultaneously tension the first end 36 and the second end 38.
The single retractor-pretensioner 44 includes a pretensioning tube 60 that houses a pyrotechnic, i.e., an explosive, that is configured to be triggered in order to rotate the spool 46. Accordingly, the single retractor-pretensioner 44 is configured to rotate the spool 46 to pull on the first and second cables 48, 50 and simultaneously tension the first and second ends 36, 38 of the lap belt 34 upon activation by the pyrotechnic. The tensioning of the first and second ends 36, 38 is performed in response to a force having a predetermined magnitude acting on the vehicle 12 and the seat 16. The contemplated force may be the type that occurs during sudden deceleration of the vehicle 12 and/or during a roll-over of the vehicle. The predetermined magnitude of the force may be established based on theoretical analysis and/or empirically during brake and impact testing of the vehicle 12. The single retractor-pretensioner 44 is configured to preemptively tighten the lap belt 34 and secure the occupant of the vehicle 12 with respect to the seat 16.
The vehicle 12 includes a controller 62. The vehicle 12 also includes a sensor 64 operatively connected to the vehicle structure 14. The sensor 64 is configured to generate a signal 66 and communicate the signal to the controller 62 in response to the force reaching the predetermined magnitude. The controller 62 is programmed to trigger the single retractor-pretensioner 44 upon receiving from the sensor 64 the signal 66 that is indicative of the predetermined magnitude of the force. As described above, the single retractor-pretensioner 44 includes the pretensioning tube 60 that houses a pyrotechnic. The pyrotechnic is used to simultaneously tension the first and second ends 36, 38 of the lap belt 34 in response to the signal 66. Each of the controller 62 and sensor 64 may be devices that are otherwise employed by the vehicle 12 for regulating the vehicle's active safety equipment, such as anti-lock braking and stability control systems.
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While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
