| 摘要 |
<p>A pretensioner for a vehicle safety restraint is described comprising two coaxial rotatable members (6, 10) having opposing surfaces spaced by a cavity (14) filled with a coupling fluid, the opposing surfaces being shaped and relatively positioned such that motion of one member relative to the other member is transmitted through the coupling fluid to the other member and wherein one member is connected to a webbing winding spool of a restraint retractor, and the other member comprises drive means actuable in response to a crash condition. Preferably, the arrangement is such that that the coupling fluid acts as a torque convertor, with the fluid containing cavity (14) located in a radial direction between the two rotary members (6, 10) and the first rotary member (10) formed as an outer rotor driven by a gas generator surrounding a cavity (14) containing the fluid and the second rotary member (6) formed as a turbine. The outer rotor comprises inwardly extending vanes (12) projecting into the fluid cavity, and the turbine comprises outwardly extending vanes (8) projecting into the fluid filled cavity, all contained in a sealed outer casing (2).</p> |
