Vacuum Cleaner Sensor

Abstract

A vacuum cleaner having an inlet nozzle for conveying air and dust to a dirt separator chamber via a dirty air inlet passage is provided. The dirt separator chamber has a chamber opening, an emitter window, and a receiver window. The emitter window and the receiver window may be substantially transparent. An emitter is positioned so that it emits light or another electromagnetic energy into the separator chamber via the emitter window. A receiver is positioned so that it receives light or another electromagnetic energy from the separator chamber via the receiver window. The emitter window and the receiver window each form a projection into the separator chamber during operation of the vacuum cleaner. Airflow creates a cyclone in the dirt separator chamber, and the projections increase the air velocity over the projections, cleaning the emitter window and the receiver window of dust.

1 . A sensor assembly for a vacuum cleaner, the sensor assembly comprising:
 a vacuum cleaner housing;   a dirt separator chamber having a dirty air inlet, a clean air outlet, an emitter window, and a receiver window;   an emitter mounted on the housing and positioned to emit electromagnetic energy through the emitter window; and   a receiver mounted on the housing and positioned to receive electromagnetic energy through the receiver window;   wherein the dirt separator chamber is removable from the housing, and at least one of the emitter window and the receiver window forms a projection into the dirt separator chamber during operation of the vacuum cleaner.   
     
     
         2 . The vacuum cleaner of  claim 1 , wherein the emitter window and the receiver window form respective projections into the dirt separator chamber during operation of the vacuum cleaner. 
     
     
         3 . The vacuum cleaner of  claim 2 , further comprising an emitter housing attached to the vacuum cleaner housing, the emitter being attached to the emitter housing. 
     
     
         4 . The vacuum cleaner of  claim 2 , further comprising a receiver housing attached to the vacuum cleaner housing, the receiver being attached to the receiver housing. 
     
     
         5 . The vacuum cleaner of  claim 1 , wherein the dirt separator chamber comprises a cyclone separator. 
     
     
         6 . The vacuum cleaner of  claim 1 , wherein a fan is adapted to convey dirty air into the dirt separator chamber under positive pressure. 
     
     
         7 . The vacuum cleaner of  claim 1 , wherein a fan is adapted to convey dirty air into the dirt separator chamber under negative pressure. 
     
     
         8 . The vacuum cleaner of  claim 1 , wherein the projection comprises a raised surface that is discontinuous from the curvature of the separator chamber. 
     
     
         9 . The vacuum cleaner of  claim 1 , wherein the projection comprises a lens. 
     
     
         10 . The vacuum cleaner of  claim 1 , wherein the dirt separator chamber is removable from the vacuum cleaner housing without removing the emitter and the receiver. 
     
     
         11 . A sensor assembly for a vacuum cleaner, the sensor assembly comprising:
 a vacuum cleaner housing;   a dirt separator chamber having a dirty air inlet, a clean air outlet, an emitter window, and a receiver window, the dirt separator chamber being adapted to contain a generally cyclonic air flow;   an emitter mounted on the housing and positioned to emit electromagnetic energy through the emitter window; and   a receiver mounted on the housing and positioned to receive electromagnetic energy through the receiver window;   wherein at least one of the emitter window and the receiver window forms a projection into the dirt separator chamber during operation of the vacuum cleaner, and wherein the velocity of the generally cyclonic air flow increases by at least about  10 % at a location adjacent the projection.   
     
     
         12 . The vacuum cleaner of  claim 11 , wherein the emitter window and the receiver window form respective projections into the dirt separator chamber during operation of the vacuum cleaner. 
     
     
         13 . The vacuum cleaner of  claim 11 , wherein the velocity of the generally cyclonic air flow increases by at least about 40% at a location adjacent the projection. 
     
     
         14 . The vacuum cleaner of  claim 11 , wherein the velocity of the generally cyclonic air flow increases by at least about 50% at a location adjacent the projection. 
     
     
         15 . The vacuum cleaner of  claim 11 , wherein the velocity of the generally cyclonic air flow increases from about 10 meters per second to about 11 meters per second at a location adjacent the projection. 
     
     
         16 . The vacuum cleaner of  claim 11 , wherein the velocity of the generally cyclonic air flow increases from about 10 meters per second to about 14 meters per second at a location adjacent the projection. 
     
     
         17 . The vacuum cleaner of  claim 11 , wherein the velocity of the generally cyclonic air flow increases from about 10 meters per second to about 15 meters per second at a location adjacent the projection. 
     
     
         18 . The vacuum cleaner of  claim 11 , wherein the boundary layer of the generally cyclonic air flow decreases by about 20% at a location adjacent the projection. 
     
     
         19 . The vacuum cleaner of  claim 11 , wherein the dirt separator chamber is removable from the vacuum cleaner housing without removing the emitter and the receiver. 
     
     
         20 . A sensor assembly for a vacuum cleaner, the sensor assembly comprising:
 a vacuum cleaner housing;   a dirt separator chamber having a dirty air inlet, a clean air outlet, an emitter window, and a receiver window, the dirt separator chamber being adapted to contain a generally cyclonic air flow;   an emitter mounted on the housing and positioned to emit electromagnetic energy through the emitter window; and   a receiver mounted on the housing and positioned to receive electromagnetic energy through the receiver window;   wherein at least one of the emitter window and the receiver window forms a projection into the dirt separator chamber during operation of the vacuum cleaner, and wherein the boundary layer of the generally cyclonic air flow decreases by about 20% at a location adjacent the projection.   
     
     
         21 . The vacuum cleaner of  claim 20 , wherein the emitter window and the receiver window form respective projections into the dirt separator chamber. 
     
     
         22 . The vacuum cleaner of  claim 21 , wherein the emitter window and the receiver window are rigidly formed with the dirt separator chamber. 
     
     
         23 . The vacuum cleaner of  claim 21 , wherein the emitter window and the receiver window are movable with respect to the dirt separator chamber. 
     
     
         24 . The vacuum cleaner of  claim 20 , wherein the dirt separator chamber is removable from the vacuum cleaner housing without removing the emitter and the receiver.