Patent ID: 6994397

Claim:
A vehicle seat assembly comprising: a seat cushion defining an upper surface and a lower surface spaced from said upper surface; and a vehicle occupant sensing system including: a plurality of sensor assemblies, each of said sensor assemblies disposed below said seat cushion adjacent said lower surface, said sensor assemblies each having a housing that includes a base and an upper slide member, said upper slide member moveable toward and away from said base and responsive to movement of said upper surface of said seat cushion toward said lower surface of said seat cushion thereby responding to the presence of an occupant in said vehicle seat; a sensor operatively fixed relative to at least one of said upper slide member and said base and operable to detect movement of said upper slide member toward and away from said base in response to the presence of an occupant in said vehicle seat; and a variable biasing member adapted to bias said upper slide member away from said base with a force that is non-linearly related to movement of said upper slide member toward and away from said base, wherein said variable biasing member includes a plurality of sections of which at least two of said sections exhibit different spring rates.