Patent ID: 6293751
Filing Date: 2001-09-25
Classification: F04D

Abstract:
An extracting blower, comprising:a fan housing;said fan housing including a front wall, a rear wall and a side wall;a rotatable fan located within said fan housing;rotating means for rotating said fan;an air intake opening in said housing front wall;a partition provided in said fan housing intermediate said housing front wall and said housing rear wall;said partition partially defining a housing front chamber and a housing rear chamber;said partition including a partition opening;a clean air outlet provided in said housing front chamber;a contaminant exhaust outlet provided in said housing rear chamber;said fan including a back plate oriented within said housing rear chamber;a plurality of fan blades extending through said partition opening from said back plate toward said housing front wall;each of said plurality of fan blades extending partially within said housing front chamber and partially within said housing rear chamber;said back plate constituting a partial barrier between said housing front chamber and said housing rear chamber;said partition opening being generally circular and concentric with said rotatable fan;said fan blades extending radially outward from a fan axis of said fan,a fan blade rear section proximate said fan back plate;a fan blade front section distal said fan back plate;said fan blade rear section oriented within said housing rear chamber;said fan blade front section oriented within said housing front chamber;each of said plurality of fan blades having a fan blade outer edge;said fan blade outer edges defining a fan blade diameter;said fan blade diameter greater than said partition opening's diameter;said plurality of fan blades provided with a fan blade notch in each of said fan blade outer edges;said partition opening having a partition edge;said fan blade notches arranged in relation to said partition so that said partition edge extends within said fan blade notches;each of said fan blades having a leading surface, said leading surface being oriented in the direction of fan rotation;a wiper provided on each of said fan blades;each said wiper affixed to said leading surface of each of said fan blades; andsaid wiper being oriented on a bias to said fan blade leading surface such that said wiper does not interpose said fan blade notch and extends proximate said fan blade outer edge.