Patent ID: 8256061

Claim:
A floor surface maintenance machine comprising: a mobile chassis having a sweeping brush; a hopper assembly for receiving debris thrown by the sweeping brush; a vacuum fan; and a filter assembly in fluid communication with the hopper assembly, said filter assembly including a cylindrical filter having a hollow interior, a pair of open ends, and a generally cylindrical filter surface, with an air flow being established through the filter surface and out one of the pair of open ends of the cylindrical filter by the vacuum fan, a shaker plate engaging the other end of the cylindrical filter, a gasket between the shaker plate and the cylindrical filter, together the gasket and shaker plate preventing an airflow through the other end of the cylindrical filter; a support frame supporting the shaker plate, and a filter shaking mechanism, said filter shaking mechanism including a motor attached to the shaker plate and being positioned at least partially within the hollow interior of the filter and an eccentric mass coupled to a shaft of the motor, said eccentric mass being rotated to remove debris from the filter surface, wherein a filter support is connected to and spaced from the shaker plate to limit a degree of compression applied to the gasket positioned between the cylindrical filter and the shaker plate.