Seat belt restraint system
First Claim
1. A seat belt retractor for a vehicle and having a locking mechanism and including an optical inertia sensor which controls the retractor locking mechanism for locking the retractor against belt protraction, the retractor comprising:
- a housing for the inertia sensor and mounted in the vehicle;
a sensor body contained in the housing;
a light emitter mounted to the sensor body to emit light therefrom;
a light detector mounted to the sensor body to receive light from the emitter which is reflected thereto;
an inertia member responsive to inertia forces and having a reflective surface for reflecting light from the emitter to the detector when the inertia member is in a first position where vehicle acceleration or deceleration is within a predetermined range;
a fixed support frame of the housing for supporting the inertia member for movement from the first position to a second position so that the reflective surface no longer reflects light to the light detector; and
an electrical circuit operable by the light detector for activating the retractor locking mechanism when the vehicle acceleration/deceleration exceeds the predetermined range limits.
2 Assignments
0 Petitions
Accused Products
Abstract
A seat belt restraint system is provided including a retractor and an optical inertia sensor therefor. The optical inertia has a sensor body with a light emitter and detector recessed in bores therein. A frame support having inclined walls with a base opening at the bottom of the walls support an inertia ball so that it is positioned at the opening to reflect light from the emitter to the detector when vehicle accelerations are within a predetermined range. The inertia sensor is incorporated into circuitry which controls a locking mechanism, e.g. solenoid, at the retractor so that when the detector is sensing light, the retractor stays unlocked. During excessive vehicle acceleration, such as brought on during accident conditions, the ball will roll along the wall so it no longer reflects light from the emitter breaking optical communication between the emitter and detector and locking the retractor. The optical inertia sensor is advantageous in that it uses very few moving parts in contrast to mechanical remote sensors and avoids the reliability problems faced by switch contacts in prior inertia sensors. In addition, the sensor body including the emitter and detector is a commercially available portion of the sensor which utilizes well proven optical components for good reliability in sensor operation and lower costs in fabricating the present sensor.
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Citations
19 Claims
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1. A seat belt retractor for a vehicle and having a locking mechanism and including an optical inertia sensor which controls the retractor locking mechanism for locking the retractor against belt protraction, the retractor comprising:
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a housing for the inertia sensor and mounted in the vehicle; a sensor body contained in the housing; a light emitter mounted to the sensor body to emit light therefrom; a light detector mounted to the sensor body to receive light from the emitter which is reflected thereto; an inertia member responsive to inertia forces and having a reflective surface for reflecting light from the emitter to the detector when the inertia member is in a first position where vehicle acceleration or deceleration is within a predetermined range; a fixed support frame of the housing for supporting the inertia member for movement from the first position to a second position so that the reflective surface no longer reflects light to the light detector; and an electrical circuit operable by the light detector for activating the retractor locking mechanism when the vehicle acceleration/deceleration exceeds the predetermined range limits. - View Dependent Claims (2, 3, 4, 5, 13)
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6. An optical inertia sensor for controlling a locking mechanism of a seat belt retractor to lock the retractor against belt protraction, the optical inertia sensor comprising:
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a housing for the inertia sensor and mounted in the vehicle; a sensor body contained in the housing; a light emitter mounted to the sensor body to emit light in a first direction therefrom; a light detector mounted to the sensor body to receive light from the emitter which is reflected thereto; a rolling inertia member responsive to inertia forces and having a reflecting surface for reflecting light from the emitter to the detector in a second direction when the vehicle acceleration or deceleration is within a predetermined range; and a fixed support frame of the housing for supporting the inertia member for rolling movement, the inertia member being restrained against rolling at a predetermined position relative to the support so as to orient the reflecting surface to reflect light from the light emitter for travel in the second direction to the detector, and the inertia member undergoing rolling movement away from the predetermined position with the reflecting surface shifted so that optical communication between the emitter and detector is broken for activating the retractor locking mechanism when the vehicle acceleration/deceleration exceeds the predetermined range limits. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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14. A seat belt restraint system for a vehicle including a seat belt retractor and a remote optical inertia sensor incorporated into a control circuit for the retractor, the seat belt restraint system comprising:
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a solenoid associated with the retractor for allowing belt protraction from the retractor when the solenoid is energized by the control circuit and locking the retractor against belt protraction when the solenoid is de-energized; a timer circuit for signalling the control circuit to energize the solenoid for a predetermined time sufficient for buckling and unbuckling of the seat belt about a passenger who is about to enter or leave the vehicle; a reflective inertia member in the sensor located in a first position when the vehicle is within predetermined acceleration and deceleration limits; a light emitter for emitting light in a first direction towards the inertia member so that the light will reflect off the inertia member when it is in the first position; and a light detector for receiving light reflected off the inertia member in a second direction to energize the solenoid for allowing belt protraction, and when the vehicle exceeds the predetermined acceleration/deceleration, the reflective inertia member shifts to break optical communication between the light emitter and detector to de-energize the solenoid for locking of the retractor regardless of signalling from the timer circuit. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification