LOCKING TONGUE FOR A SAFETY BELT

• US 20120068520A1
• Filed: 09/20/2011
• Published: 03/22/2012
• Est. Priority Date: 09/20/2010
• Status: Active Grant

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: McFalls, Bob L., Rosso, Jeffery, Betz, Hans-Peter, Haas, Peter, Donnellon, John J., Hartman, Andrew F., Gleason, Michael P.
• Granted Patent: US 8,793,844 B2
• Time in Patent Office: Days
• US Class Current: 297/468
• CPC Class Codes: A44B 11/2553 Attachment of buckle to strap
• CPC Class Codes: A44B 11/2561 Tongue elements
• CPC Class Codes: Y10T 24/4016 Pivoted part or lever
• CPC Class Codes: Y10T 24/4047 Strap loops and attaching devices
• CPC Class Codes: Y10T 24/45241 Slot and tab or tongue

Abstract

A locking tongue has a base part, a webbing slot in the base part and a locking cam. The locking cam is movable between a rest position and a clamping position. A biasing means biases the locking cam towards the rest position. The locking cam can assume the rest position in which the belt webbing can pass freely through the webbing slot, a clamping position in which the locking cam presses the belt webbing against the clamping edge of the webbing slot, the biasing means being able to return the locking cam from the clamping position into the rest position, and a locking position in which the locking cam locks the belt webbing in the webbing slot, the biasing means not being able to return the locking cam from the locking position towards the rest position.

Claims

1. A locking tongue (10) for a seat belt system, having a base (11), a webbing slot (16) in the base through which the belt webbing (44) can extend, and a locking cam (20) associated to the webbing slot (16) and supported at the base, the locking cam (20) being movable between a rest position and a clamping position, wherein a biasing means (26;

70) is provided which biases the locking cam (20) towards the rest position.

2. The locking tongue of claim 1 wherein the biasing means is a metal spring (26).

3. The locking tongue of claim 2 wherein the biasing means is a torsion spring (26).

4. The locking tongue of claim 1 wherein the biasing means is an elastomeric spring (70).

5. The locking tongue of claim 4 wherein the elastomeric spring (70) is formed with at least two distinct compression segments (72,74,76).

6. The locking tongue of claim 1 wherein a shear pin (82) is provided which can be sheared off by the locking cam (20).

7. The locking tongue of claim 1 wherein the locking cam (20) is mounted pivotably on a pivot stud (22), the pivot stud (22) being connected to the base part by means of a plastics overmould fixed to the base part.

8. The locking tongue of claim 1 wherein the locking cam (20) is mounted pivotably on a pivot stud (22), the pivot stud (22) being held in bearing portions (50) formed integrally with the base.

9. A combination of a locking tongue according to claim 1 and a seat belt, the belt webbing (44) extending through the webbing slot (16), an edge of the webbing slot (16) acting as a clamping edge (42) against which the belt webbing can be pressed by the locking cam (20), the dimensions of the webbing slot (16), the locking cam (20) and the belt webbing (44) being adjusted such that the locking cam (20) can assume at least three positions, namely the rest position in which the belt webbing (44) can pass freely through the webbing slot (16), a clamping position in which the locking cam (20) presses the belt webbing (44) against the clamping edge (42) of the webbing slot (16) such that the belt webbing (44) is tightly clamped, the biasing means (26;

70) being able to return the locking cam (20) from the clamping position into the rest position, and a locking position in which the locking cam (20) locks the belt webbing (44) in the webbing slot (16), the biasing means (26;

70) not being able to return the locking cam (20) from the locking position towards the rest position.

10. The combination of claim 9 wherein a shear pin (82) is provided which defines the clamping position.