US Patent 7938871 Vehicle filter assembly

A vehicle filter assembly includes a housing, a cyclone-inducing structure and a self-cleaning trap mechanism. The housing has an inlet, an outlet and a trap aperture. The cyclone-inducing structure is disposed within the housing between the inlet and the outlet to separate particulate from gases passing through the housing from the inlet to the outlet. The self-cleaning trap mechanism is movably arranged with respect to the trap aperture to move between a closed orientation sealing the trap aperture and an opened orientation exposing the trap aperture to release particulate from the housing.