Seat belt retractor and its spool

• US 5,984,223 A
• Filed: 10/27/1998
• Issued: 11/16/1999
• Est. Priority Date: 06/05/1998
• Status: Expired due to Term

• Current Assignee: Joyson Safety Systems Japan K.K.
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Hiramatsu, Koji
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): Rivera, William A.
• Application Number:
  US09/179,591
• Time in Patent Office: 385 Days
• Field of Search: 242/374, 242/376, 242/379.1, 280/805, 280/806, 297/480
• US Class Current: 242/379.1
• CPC Class Codes: B60R 2022/3427 Seat belt connection on reels
• CPC Class Codes: B60R 22/4676 comprising energy-absorbing means operating between belt reel and retractor frame

Abstract

In a spool, a torsion bar is inserted into an inner hole formed in the spool. The spool has a first slit and a second slit which extend in parallel with each other along the chord direction in the cross section perpendicular to the axis of the inner hole. The end of the webbing is passed through these slits. The end of the webbing is folded back and sewn together to form a loop and a webbing stopper is inserted into the loop made by folding and sewing. The end of the webbing with the webbing stopper engages the second slit.

Claims

1. A spool for a seat belt retractor for winding a webbing comprising a cylindrical portion provided with an inner hole into which a torsion bar is inserted,

wherein said cylindrical portion is provided with a plurality of slits extending along a chord direction in the cross section perpendicular to the axis of said cylindrical portion so that the webbing is fixed to said spool by passing an end of the webbing through said slits.

2. A spool according to claim 1, wherein the number of said slits is two and said slits are disposed in parallel with each other in said section.

3. A seat belt retractor having a torsion bar connected to a spool so that impact exerted to an occupant is absorbed,

wherein said spool has a cylindrical portion provided with an inner hole into which said torsion bar is inserted, and

wherein said cylindrical portion is provided with a plurality of slits extending along a chord direction in the cross section perpendicular to the axis of said cylindrical portion so that the webbing is fixed to said spool by passing an end of the webbing through said slits.

4. A seat belt retractor according to claim 3, wherein the number of said slits is two and said slits are disposed in parallel with each other in said section.

5. A seat belt retractor comprising

a cylindrical spool for winding a webbing,

a frame supporting said spool,

a torsion bar which is inserted into an inner hole of said spool and fixed to said spool at one end thereof, and

a locking means for locking the other end of said torsion bar when acceleration exceeding a predetermined value is sensed,

said torsion bar being capable of twisting when tensile force exceeding a predetermined value is exerted to the webbing at a state in which said locking means has locked said other end of the torsion bar,

wherein said locking means comprises

a pawl holder which is locked to said frame when the acceleration exceeding the predetermined value is sensed,

a column which projects from said pawl holder and is inserted into the inner hole of said spool,

a male thread which is formed in the outer surface of said column,

a stopper member having a female thread formed in the inner surface thereof which is screwed on said male thread, said stopper member being slidable back and forth in axial direction along said column,

a plurality of projections which project from said stopper member in the direction including the radial direction, and

recesses which are formed in the inner hole of said spool and with which said projections are engaged;

and

wherein said stopper member is driven toward said pawl holder when said locking means has operated and the torsion bar twists by the tensile force exceeding the predetermined value exerted to the webbing and, after that, the stopper member comes in contact with the pawl holder, thereby transmitting the torque of the spool to the pawl holder via said stopper member and stopping the further rotation of the spool.

6. A seat belt retractor according to claim 5, wherein said spool has a cylindrical portion provided with said inner hole and that said cylindrical portion is provided with a plurality of slits extending along a chord direction in the cross section perpendicular to the axis of said cylindrical portion so that the webbing is fixed to said spool by passing an end of the webbing through said slits.

7. A seat belt retractor according to claim 6, wherein the number of said slits is two and said slits are disposed in parallel with each other in said section.