US Patent 7116220 Seat belt latch sensor assembly

A mechanical engagement system such as a seat belt assembly includes a housing and a slider slidably received within the housing, the slider is configured for movement between a first position and a second position within the housing. A single magnet is associated with the slider for slidable movement therewith while a hall effect device is fixed relative to the housing. The hall effect device is fixed relative to the housing and aligned with at the single magnet when the slider is in the second position. The hall effect device is configured to generate an output signal indicative of a latch condition of the mechanical engagement system as applied to the sensor assembly.