Seat belt retractor employing ultrasonic motor
First Claim
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1. A seat belt retractor comprising:
- a) a reel having a shaft for reeling and unreeling a seat belt;
b) an ultrasonic motor for rotating the shaft, the ultrasonic motor comprising;
1) a plurality of piezo-electric devices, said piezo-electric devices receiving a control signal for actuating said ultrasonic motor,2) a stator secured to said piezo-electric devices and3) a rotor placed adjacent said stator;
c) said rotor integral with or rigidly attached to said shaft for rotating said shaft upon actuation of said motor, said shaft rotating in a first direction to retract said seat belt and rotating in a second, opposite direction to extract said seat belt; and
d) a control device for controlling the rotation of the ultrasonic motor by supplying said control signal to said ultrasonic motor.
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Accused Products
Abstract
A reel of a seat belt retractor equipped in a automobile for reeling a seat belt is integral with a shaft of an ultrasonic motor. The ultrasonic motor is rotated either one direction or the other so as to retract or draw out the seat belt. A control device for controlling the rotation of the ultrasonic motor by supplying a control signal based on the signals sensed by a buckle sensor which senses a buckle is locked, a tension sensor which senses tension of a seat belt, a speed sensor which senses speed of the automobile, a rotation sensor which senses the rotation degree and a child seat sensor which senses whether child seat is set on a passenger seat.
149 Citations
20 Claims
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1. A seat belt retractor comprising:
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a) a reel having a shaft for reeling and unreeling a seat belt; b) an ultrasonic motor for rotating the shaft, the ultrasonic motor comprising; 1) a plurality of piezo-electric devices, said piezo-electric devices receiving a control signal for actuating said ultrasonic motor, 2) a stator secured to said piezo-electric devices and 3) a rotor placed adjacent said stator; c) said rotor integral with or rigidly attached to said shaft for rotating said shaft upon actuation of said motor, said shaft rotating in a first direction to retract said seat belt and rotating in a second, opposite direction to extract said seat belt; and d) a control device for controlling the rotation of the ultrasonic motor by supplying said control signal to said ultrasonic motor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of reeling and unreeling a seat belt from a reel of a retractor attached to a vehicle comprising the steps of:
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a) positioning an ultrasonic motor adjacent said shaft of said reel, b) sensing at least one condition of at least one of said vehicle and said belt, c) actuating said ultrasonic motor for one of reeling and unreeling in response to said sensed condition.
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18. A seat belt retractor comprising:
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a seat belt reel having a shaft; an ultrasonic motor including a ring-shaped piezoelectric device array, a ring-shaped stator in substantial contact with the piezoelectric device array, and a ring-shaped rotor rotatable with both the stator and the shaft, the piezoelectric device array flexing in a wavelike manner according to ultrasonic control signals supplied thereto, the stator being rotated in response to the flexing of the piezoelectric device array to cause the rotor and the shaft to rotate therewith; and a control device for supplying the ultrasonic control signals to the ultrasonic motor. - View Dependent Claims (19, 20)
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Specification