Friction clutch and belt retractor with friction clutch

• US 6,454,201 B1
• Filed: 07/11/2000
• Issued: 09/24/2002
• Est. Priority Date: 07/12/1999
• Status: Expired due to Term

• Current Assignee: TRW Occupant Restraint Systems GmbH & Co. KG
• Original Assignee: TRW Occupant Restraint Systems GmbH & Co. KG
• Inventors: Strobel, Ralf, Weller, Hermann-Karl
• Primary Examiner(s): Jillions, John M.
• Application Number:
  US09/614,098
• Time in Patent Office: 805 Days
• Field of Search: 242/379.1, 280/806, 297/478, 464/81, 464/82, 464/41, 464/42, 464/45
• US Class Current: 242/379.1
• CPC Class Codes: B60R 2022/285 using friction surfaces
• CPC Class Codes: B60R 22/3413 operating between belt reel and retractor frame B60R22/4676 takes precedence
• CPC Class Codes: B60R 22/4676 comprising energy-absorbing means operating between belt reel and retractor frame
• CPC Class Codes: F16D 7/021 with radially applied torque-limiting friction surfaces F16D7/022 takes precedence

Abstract

A belt retractor comprises a belt spool rotatably mounted in a frame, a locking mechanism for the belt spool with at least one locking disc connected to the belt spool, and a torque limiting member arranged in a force flow path between the belt spool and the locking disc. The torque limiting member is constructed as a friction clutch comprising two clutch faces lying opposite each other and a friction member arranged between the clutch faces. The friction member is constructed as a flat spring part having shaped sections. The shaped sections lie at least partially against at least one of the clutch faces.

Claims

1. A belt retractor comprising a belt spool rotatably mounted in a frame, a locking mechanism for said belt spool with at least one locking disc connected to said belt spool, and a torque limiting member arranged in a force flow path between said belt spool and said locking disc, said torque limiting member being constructed as a friction clutch comprising first and second clutch faces lying opposite each other and a friction member arranged between said first and second clutch faces, said friction member being constructed as a flat spring part having shaped sections, said shaped sections lying at least partially against at least one of said first and second clutch faces, wherein a first clutch plate is provided which is connected non-rotatably with said belt spool and includes said first clutch face and wherein a second clutch plate is provided which is connected non-rotatably with said locking disc and includes said second clutch face and a plate being arranged between said first and second clutch faces which has said elastic shaped sections, each of said shaped sections having a cross-section in the form of a circular arc.

2. The belt retractor according to claim 1 wherein said spring plate is a unitary annular shaped structure defined by a plurality of continuously extending elastic shaped sections.

3. A belt retractor comprising a belt spool rotatably mounted in a frame, a locking mechanism for said belt spool with at least one locking disc connected to said belt spool, and a torque limiting member arranged in a force flow path between said belt spool and said locking disc, said torque limiting member being constructed as a friction clutch comprising first and second clutch faces lying opposite each other and a friction member arranged between said first and second clutch faces, said friction member being constructed as a flat spring part having shaped sections, said shaped sections lying at least partially against at least one of said first and second clutch faces, wherein a first cylinder face is provided which is connected non-rotatably with said belt spool and includes said first clutch face and a second cylinder face is provided which is connected non-rotatably with said locking disc and includes said second clutch face, and a cylinder being arranged between said first and second clutch faces which has said elastic shaped sections.

4. The belt retractor according to claim 3 wherein said friction member exerts a radial force between said first and second clutch faces.

5. The belt retractor according to claim 3 wherein said spring plate is a unitary annular shaped structure defined by a plurality of continuously extending elastic shaped sections.

6. The belt retractor according to claim 3 wherein said first clutch face is formed by a side face of an extension of a belt spool axle and said second clutch face is formed by an inner face of a hollow cylinder connected to said locking disc.