Variable load limiting restraint retractor

• US 6,481,659 B1
• Filed: 04/07/2000
• Issued: 11/19/2002
• Est. Priority Date: 04/07/2000
• Status: Expired due to Term

• Current Assignee: Autoliv AB (Autoliv Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Ashtiani, Mansour, Kruckemeyer, William Charles, Oliver, Michael Leslie, Sickon, Richard P
• Primary Examiner(s): RIVERA, WILLIAM ARAUZ
• Application Number:
  US09/544,792
• Time in Patent Office: 956 Days
• Field of Search: 242/379.1, 242/381, 280/805, 280/806, 280/807
• US Class Current: 242/379.1
• CPC Class Codes: B60R 2022/282 using fluids or vico-elastic materials
• CPC Class Codes: B60R 2022/284 using electric or magnetic braking means
• CPC Class Codes: B60R 2022/288 with means to adjust or regulate the amount of energy to be absorbed
• CPC Class Codes: B60R 22/3413 operating between belt reel and retractor frame B60R22/4676 takes precedence

Abstract

A variable load limiting restraint retractor for a seat restraint system in a vehicle includes a housing for operative connection to vehicle structure. The variable load limiting restraint retractor also includes a take-up spool operatively connected to the housing and connected to a belt of a seat restraint system for winding and unwinding the belt. The variable load limiting restraint retractor includes a rotatable shaft operatively connected to the take-up spool and the housing, the take-up spool being mounted on the shaft. The variable load limiting restraint retractor further includes a load limiting assembly operatively connected to the shaft for variably limiting load on the belt when the seat restraint system is in a buckled position.

Claims

1. A variable load limiting restraint retractor for a seat restraint system in a vehicle comprising:

a housing for operative connection to vehicle structure;

a take-up spool operatively connected to said housing and connected to a belt of a seat restraint system for winding and unwinding the belt;

a rotatable shaft operatively connected to said take-up spool and said housing, said take-up spool being mounted on said shaft; and

a load limiting assembly including a rotatable piston operatively connected to said shaft for rotation with said shaft and for translating in a linear manner when an impact of the vehicle is sensed, a fluid cooperating with said piston, and an electrical coil for applying a magnetic field to said fluid to change a viscosity of said fluid for variably limiting load on the belt when the seat restraint system is in a buckled position.

2. A variable load limiting restraint retractor as set forth in claim 1 wherein said load limiting assembly includes a housing and said piston being disposed within said housing for cooperating with said shaft.

3. A variable load limiting restraint retractor as set forth in claim 2 wherein said fluid is either one of a magnetorheological (MR) fluid and electrorheological (ER) fluid disposed in said housing and cooperating with said piston.

4. A variable load limiting restraint retractor as set forth in claim 3 wherein said electrical coil is disposed in said housing and connected to a source of power.

5. A variable load limiting restraint retractor as set forth in claim 2 wherein said load limiting assembly includes a plate member cooperating with said housing and said piston to prevent rotation of said piston.

6. A variable load limiting restraint retractor as set forth in claim 2 wherein housing includes a cavity in one axial end and a passageway extending axially through another axial end and communicating with said cavity.

7. A variable load limiting restraint retractor for a seat restraint system in a vehicle comprising:

a housing for operative connection to vehicle structure;

a take-up spool operatively connected to said housing and connected to a belt of a seat restraint system for winding and unwinding the belt;

a rotatable shaft operatively connected to said take-up spool and said housing, said take-up spool being mounted on said shaft;

a load limiting assembly operatively connected to said shaft for variably limiting load on the belt when the seat restraint system is in a buckled position;

said load limiting assembly including a housing and a piston disposed within said housing for cooperating with said shaft;

said housing including a cavity in one axial end and a passageway extending axially through another axial end and communicating with said cavity; and

said piston comprising a piston portion disposed in said cavity and extending radially to a wall of said cavity to form a gap therebetween and a shaft portion extending axially from said piston portion and through said passageway.

8. A variable load limiting restraint retractor as set forth in claim 7 wherein said shaft portion has an aperture extending therein and a plurality of first threads disposed about said aperture.

9. A variable load limiting restraint retractor as set forth in claim 8 wherein said shaft includes a plurality of second threads for threadably engaging said first threads.

10. A variable load limiting restraint retractor as set forth in claim 7 wherein said load limiting assembly includes a seal disposed in said cavity and about said shaft portion to form a chamber.

11. A variable load limiting restraint retractor as set forth in claim 7 wherein said load limiting assembly includes a seal disposed between said housing and said shaft portion.

12. A variable load limiting restraint retractor for a seat restraint system in a vehicle comprising:

a retractor housing for operative connection to vehicle structure;

a take-up spool operatively connect ed to said retractor housing and connected to a belt of a seat restraint system for winding and unwinding the belt;

a rotatable shaft operatively connected to said take-up spool and said retractor housing, said take-up spool being mounted on said shaft; and

a load limiting assembly including a rotatable piston operatively connected to said shaft for rotation with said shaft and for translating in a linear manner when an impact of the vehicle is sensed, either one of a magnetorheological (MR) fluid and electrorheological (ER) fluid cooperating with said piston, and an electrical coil for applying a magnetic field to said fluid to increase a viscosity of said fluid for variably limiting load on the belt during the impact.

13. A variable load limiting restraint retractor as set forth in claim 12 wherein said load limiting assembly includes a load limiting housing and said piston being disposed within said load limiting housing for cooperating with said shaft, said fluid being disposed in a chamber of said load limiting housing and cooperating with said piston.

14. A variable load limiting restraint retractor as set forth in claim 13 wherein said electrical coil is disposed in said load limiting housing and connected to a source of power.

15. A variable load limiting restraint retractor as set forth in claim 13 wherein said load limiting assembly includes a plate member cooperating with said piston to prevent rotation of said piston and cooperating with said load limiting housing to prevent rotation of said plate member.

16. A variable load limiting restraint retractor as set forth in claim 15 including a spring disposed between said retractor housing and said load limiting housing to urge said plate member against said load limiting housing.

17. A variable load limiting restraint retractor as set forth in claim 13 wherein load limiting housing includes a cavity in one axial end and a passageway extending axially through another axial end and communicating with said cavity.

18. A variable load limiting restraint retractor for a seat restraint system in a vehicle comprising:

a retractor housing for operative connection to vehicle structure;

a take-up spool operatively connected to said retractor housing and connected to a belt of a seat restraint system for winding and unwinding the belt;

a rotatable shaft operatively connected to said take-up spool and said retractor housing, said take-up spool being mounted on said shaft;

a load limiting assembly operatively connected to said shaft including either one of a magnetorheological (MR) fluid and electrorheological (ER) fluid for variably limiting load on the belt when the seat restraint system is in a buckled position;

said load limiting assembly including a load limiting housing and a piston disposed within said load limiting housing for cooperating with said shaft, said fluid being disposed in a chamber of said load limiting housing and cooperating with said piston;

said load limiting housing including a cavity in one axial end and a passageway extending axially through another axial end and communicating with said cavity; and

said piston comprising a piston portion disposed in said cavity and extending radially to a wall of said cavity to form a gap therebetween and a shaft portion extending axially from said piston portion and through said passageway.

19. A variable load limiting restraint retractor as set forth in claim 18 wherein said shaft portion has an aperture extending therein and a plurality of first threads disposed about said aperture and said shaft includes a plurality of second threads for threadably engaging said first threads.

20. A seat restraint system for a vehicle comprising:

a belt for restraining an occupant in the vehicle;

a variable load limiting restraint retractor for operative connection to the vehicle and connected to said belt for winding and unwinding the belt;

said variable load limiting restraint retractor comprising a retractor housing, a take-up spool operatively connected to said retractor housing and connected to said belt;

a rotatable shaft operatively connected to said take-up spool; and

a load limiting assembly including a rotatable piston operatively connected to said shaft for rotation with said shaft and for translating in a linear manner when an impact of the vehicle is sensed, a fluid cooperating with said piston, and an electrical coil for applying a magnetic field to said fluid to change a viscosity of said fluid for variably limiting load on the belt during the impact.