Seat belt retractor and seat belt apparatus employing the same

• US 20080203808A1
• Filed: 01/22/2008
• Published: 08/28/2008
• Est. Priority Date: 02/28/2007
• Status: Abandoned Application

• Current Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Yoshioka, Hirokazu, Fukuoka, Yasunori
• Application Number:
  US12/010,144
• Publication Number:
  US 20080203808A1
• Time in Patent Office: Days
• US Class Current: 297/478
• CPC Class Codes: B60R 2022/468 characterised by clutching means between actuator and belt reel
• CPC Class Codes: B60R 22/405 responsive to belt movement and vehicle movement

Abstract

A seat belt retractor includes a seat belt, a spool for winding the seat belt, an operation member, and a planetary gear mechanism for transmitting a rotation of the spool to the operation member and actuating the operation member. The planetary gear mechanism includes a carrier to which rotation of the spool is transmitted, a planetary gear rotatably supported by the carrier and an internal gear for meshing with the planetary gear and actuating the operation member. The carrier, planetary gear and internal gear are structured as a sub-assembly which is assembled to the seat belt retractor.

Claims

1. A seat belt retractor, comprising:

a seat belt;

a spool for winding the seat belt;

an operation member; and

a planetary gear mechanism for transmitting rotation of said spool to the operation member and actuating the operation member, said planetary gear mechanism comprising a carrier to which rotation of said spool is transmitted, a planetary gear rotatably supported by said carrier and an internal gear for meshing with said planetary gear and actuating said operation member,

wherein said carrier, said planetary gear, and said internal gear are structured as a sub-assembly which is assembled to the seat belt retractor.

5. A seat belt apparatus, comprising:

a seat belt to be worn by an occupant;

a seat belt retractor for winding said seat belt while allowing a withdrawal of said seat belt in a normal condition and preventing withdrawal of the seat belt in an emergency condition;

a tongue slidably supported by said seat belt; and

a buckle attached to a vehicle body or a vehicle seat, said buckle detachably latching to the tongue,

wherein said seat belt retractor is the seat belt retractor as claimed in claim 1.

2. A seat belt retractor, comprising:

a seatbelt;

a spool for winding the spool;

a locking mechanism for allowing rotation of said spool in an inoperative condition and preventing the rotation of said spool in a belt withdrawing direction in an operative condition;

a belt withdrawal sensor actuated when said seat belt is rapidly withdrawn at a speed exceeding a predetermined speed;

a lock actuating device for actuating said locking mechanism according to an actuation of said belt withdrawal sensor;

a lock gear disposed in said lock actuating device so that said lock gear rotates together with said spool in the inoperative condition and said lock gear rotates relative to said spool in the operative condition and actuates said locking mechanism by a relative rotation to said spool, wherein said belt withdrawal sensor is disposed on said lock gear so that said belt withdrawal sensor can move between an inoperative position where the lock gear is allowed to rotate both in a belt winding direction and the belt withdrawing direction and an operative position where the lock gear is prevented from rotating at least in the belt withdrawing direction;

a movement preventive member provided in said lock gear for preventing movement of said belt withdrawal sensor such that said movement preventive member moves between a movement preventing position where said belt withdrawal sensor is held at said inoperative position to prevent the movement of said belt withdrawal sensor at least when said seat belt is maximally wound and a movement allowing position where the movement of said belt withdrawal sensor is allowed when said seat belt is withdrawn by a predetermined amount or more; and

a movement preventive member control device provided in said lock gear for controlling movement of said movement preventive member, said movement preventive member control device comprising a movement control member for controlling the movement of the movement preventive member in rotating according to the rotation of said spool, and an intermittent relative rotation device for intermittently rotating said movement control member relative to said lock gear;

wherein said intermittent relative rotation device comprises a carrier for rotating together with said spool, a planetary gear rotatably supported by said carrier, an internal gear disposed on said movement control member and meshing with the internal gear, and a planetary gear control device for alternately and repeatedly setting, in the rotation of the carrier, the planetary gear to a state where said planetary gear only revolves and to a state where said planetary gear revolves and also rotates on its axis.

3. A seat belt retractor as claimed in claim 2, wherein said carrier, said planetary gear, and said internal gear are structured as a sub-assembly and are assembled to the seat belt retractor.

4. A seat belt retractor as claimed in claim 3, wherein said movement control member is a cam plate including a cam groove and rotating together with said internal gear, and said movement preventive member is provided with a cam follower inserted into and guided by said cam groove.