Method of controlling seatbelt retracting device with motor

• US 7,251,111 B2
• Filed: 06/17/2004
• Issued: 07/31/2007
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: Joyson Safety Systems Japan GK
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Tanaka, Koji, Inuzuka, Koji
• Primary Examiner(s): Leykin; Rita
• Application Number:
  US10/868,932
• Publication Number:
  US 20050077412A1
• Time in Patent Office: 1,139 Days
• Field of Search: 361/31, 242/390, 242/420.05, 318/254, 280/807, 280/801.1
• US Class Current: 318/400.01
• 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 2022/4473 using an electric retraction device combined with a spring B60R2022/444, B60R2022/4466
• CPC Class Codes: B60R 2022/4486 for cancelling the belt tension
• 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

In controlling a seatbelt retracting device having a mechanism for retracting a seatbelt with a motor, a current flowing to the motor is detected, and a rate of increase in the current is calculated. When the rate of increase exceeds a predetermined value, the motor is stopped. When the current exceeds a predetermined value, the motor is stopped as well.

Claims

1. A method of controlling a seatbelt retracting device with a motor, comprising:

supplying electricity to a motor for retracting a seatbelt,

detecting the electricity flowing to the motor for retracting the seatbelt at a predetermined interval,

calculating a difference with respect to a value read previously to find a rate of increase in the electricity,

awaiting a predetermined period since the electricity is supplied to the motor, and

starting to control the motor including stopping the motor when the rate of increase of the electricity exceeds a predetermined rate.

2. A method of controlling a seatbelt retracting device according to claim 1, wherein said stopping the motor is also made when the electricity flowing to the motor exceeds a predetermined value.

3. A method of controlling a seatbelt retracting device according to claim 1, wherein said electricity is current.

4. A method of controlling a seatbelt retracting device according to claim 1, wherein said motor is connected to the seat belt through a clutch, said motor and clutch being controlled by a control circuit.

5. A method of controlling a seatbelt retracting device according to claim 1, wherein said predetermined time since the electricity is supplied to the motor is a substantial period until an acceleration of the motor is completed.