Seat belt pretensioner

• US 7,673,906 B2
• Filed: 08/11/2008
• Issued: 03/09/2010
• Est. Priority Date: 07/12/2005
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Bell, John Forster
• Primary Examiner(s): Dickson; Paul N
• Assistant Examiner(s): Verley; Nicole
• Application Number:
  US12/228,134
• Publication Number:
  US 20090045615A1
• Time in Patent Office: 575 Days
• Field of Search: 280/806, 297/470, 297/471, 297/472, 297/479, 180/268
• US Class Current: 280/806
• CPC Class Codes: B60R 2022/263 Front seats
• CPC Class Codes: B60R 22/1951 characterised by arrangements in vehicle or relative to seat belt
• CPC Class Codes: B60R 22/26 secured to the seat

Abstract

A pretensioning apparatus for seat belt webbing is located in the vicinity of a belt anchor end of a three-point vehicle safety restraint seat belt. The pretensioning apparatus has a fixed member in the form of a tubular member that may be anchored to a vehicle seat at the belt anchor side of the vehicle. A movable member in the form of a piston is connected to the webbing in the region of the belt anchor end. A means is provided for moving the movable member relative to the fixed member in a generally horizontal direction, to move the seat belt webbing in a pretensioning direction in response to a signal from a crash sensor. A webbing guide is fixed to the seat to provide an effective anchorage point spaced from the belt anchor end of the webbing under pretensioning conditions.

Claims

1. A pretensioning apparatus for tensioning a seat belt webbing of a three point seat belt that is installed in a vehicle, the pretensioning apparatus comprising:

a tubular member anchored to a load bearing part of a vehicle seat such that the tubular member extends in a direction going from the front of the vehicle towards the rear of the vehicle;

a piston located inside of the tubular member, the piston being movable along the tubular member towards the rear of the vehicle in the event of a vehicle crash;

a seat belt webbing guide fixed to the seat rearward of and lower than the tubular member;

a cable having a first end that is attached to the piston, the cable extending from the piston in a forward direction then around a pulley that redirects the cable in a rearward direction, the cable being attached to an end of the seat belt; and

when the piston is moved rearward along the interior of the cylinder the cable pulls the seat belt webbing against the seat belt webbing guide toward the front of the vehicle.