Electric vacuum cleaner

Claim 1

An electric vacuum cleaner comprising suction means mounted on a base plate, a dust collecting case being open at its upper side and removably mounted on said base plate to enclose said suction means, an openable cover provided on the opening on the upper side of said dust collecting case, means defining a first air passageway for a dust-containing air flow in said case extending from a first suction opening provided in the dust collecting case on the upstream side of said suction means and communicating therewith, means defining a second air passageway in said case for an air flow created by said suction means extending from a second air intake opening in said cover member provided centrally of the upper surface of said cover to the upstream side of said suction means and communicating therewith, an air turbine rotatably disposed in said second air passageway, filter means provided in said first air passageway for collecting the dust in the air flow passing in said first air passageway, a dust removing device provided on the inner surface of the cover adjacent said filter means and driven by said air turbine to deflect the filter means to remove the dust deposited on said filter means, and switching means provided on a hollow shaft formed on the inner surface of said cover for directing the air flow selectively into said first and second air passageway by closing flow communication of said suction means to said second air passageway during the filtering operation and closing flow communication of said suction means to said first air passageway during the dust removing operation, said switching means being composed of a cylindeR having a flat portion at the lower end thereof, said flat portion having formed therein a plurality of outer sectral air passage holes and a plurality of inner sectral air passage holes, and a filter supporting plate in contact with said flat portion of said cylinder and having outer air passage holes and inner passage holes formed therein at locations corresponding to and in the same shape as said outer air passage holes and inner passage holes in said flat portion, and further said cylinder being rotatably mounted on said hollow shaft provided on the cover and said switching means further including means for rotating said cylinder.