Seat belt retractor and seat belt apparatus

• US 20060016926A1
• Filed: 06/23/2005
• Published: 01/26/2006
• Est. Priority Date: 07/21/2004
• Status: Active Grant

• Current Assignee: Joyson Safety Systems Japan K.K.
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Tanaka, Koji
• Granted Patent: US 7,506,833 B2
• Time in Patent Office: Days
• US Class Current: 242/374
• CPC Class Codes: B60R 2022/444 the additional retraction device being an electric actuator
• CPC Class Codes: B60R 2022/4466 the additional retraction device being an electric actuator
• CPC Class Codes: B60R 22/44 with means for reducing belt tension during use under normal conditions not included in the retractor B60R22/19; B60R22/3405 takes precedence

Abstract

A seat belt retractor includes a spring for rotating a reel in a belt winding direction to wind up a seat belt, and a motor for generating rotational power capable of rotating the reel in the belt winding direction to wind up the seat belt. A motor control unit controls the motor to generate the rotational power to wind up the seat belt with a desired winding force.

Claims

1. A seat belt retractor comprising:

a reel for winding a seat belt,

a spring attached to the reel for rotating the reel in a belt winding direction,

a motor attached to the reel for generating rotational power capable of rotating the reel in the belt winding direction, and

a motor control unit for controlling the motor to wind the seat belt with a desired winding force.

2. A seat belt retractor according to claim 1, further comprising a power transmission path disposed between the motor and the reel, and a clutch mechanism attached to the power transmission path for switching between a mode allowing transmission of power and a mode halting the transmission of power.

3. A seat belt retractor according to claim 1, wherein said motor is connected to the spring for winding the seat belt with the desired winding force.

4. A seat belt retractor according to claim 1, further comprising a setting unit for setting the desired winding force through the motor control unit.

5. A seat belt retractor according to claim 1, wherein said motor control unit includes a buckle switch for detecting that the seat belt is worn, and a motor current detector for detecting a current flowing through the motor.

6. A seat belt apparatus comprising the seat belt retractor according to claim 1, a seat belt having an end fixed to the reel, a tongue attached to the seat belt, and a buckle for engaging the tongue.