Filter assembly for a surface cleaning apparatus

Abstract

A surface cleaning apparatus comprises a cyclone, a suction motor positioned downstream from the cyclone and a filter assembly downstream of the cyclone and upstream of the suction motor. The filter assembly comprises a longitudinally extending first filter media configured as a hollow body, a longitudinally extending secondary filter positioned interior the longitudinally extending first filter media, the longitudinally extending secondary filter configured as a hollow body and an inner longitudinally extending downstream air flow passage positioned transversely inwardly from the inner downstream surface of the longitudinally extending secondary filter. A longitudinally extending filter axis is generally parallel to a motor axis and intersects the suction motor. The secondary filter filters finer particulate matter than the longitudinally extending first filter media.

1 - 32 . (canceled) 
     
     
         33 . A surface cleaning apparatus comprising:
 a) an air flow passage extending from a dirty air inlet to a clean air outlet;   b) a cyclone positioned in the air flow passage and having a cyclone air inlet, a cyclone air outlet and a cyclone axis;   c) a suction motor positioned in the air flow passage and having a longitudinally extending motor axis; and,   d) a filter assembly downstream of the cyclone air outlet and upstream of the suction motor, the filter assembly comprising:
 i) a longitudinally extending first filter media configured as a hollow body and having a filter axis, an outer upstream surface and an inner downstream surface positioned transversely inwardly from the outer upstream surface; 
 ii) a longitudinally extending secondary filter positioned interior the longitudinally extending first filter media, the longitudinally extending secondary filter configured as a hollow body and having an outer upstream surface positioned transversely inwardly from the inner downstream surface of the longitudinally extending first filter media and an inner downstream surface positioned transversely inwardly from the outer upstream surface of the longitudinally extending secondary filter; and, 
 iii) an inner longitudinally extending downstream air flow passage positioned transversely inwardly from the inner downstream surface of the longitudinally extending secondary filter, 
   wherein the longitudinally extending filter axis is generally parallel to the motor axis and intersects the suction motor and wherein the secondary filter filters finer particulate matter than the longitudinally extending first filter media.   
     
     
         34 . The surface cleaning apparatus of  claim 33  wherein the longitudinally extending first filter media is substantially annular. 
     
     
         35 . The surface cleaning apparatus of  claim 34  wherein the inner downstream surface is circular in transverse section. 
     
     
         36 . The surface cleaning apparatus of  claim 33  wherein the longitudinally extending filter axis is coaxial with the motor axis. 
     
     
         37 . The surface cleaning apparatus of  claim 33  wherein the longitudinally extending first filter media comprises a foam filter. 
     
     
         38 . The surface cleaning apparatus of  claim 33  wherein the cyclone axis is generally parallel to the motor axis. 
     
     
         39 . The surface cleaning apparatus of  claim 38  wherein the cyclone axis is generally co-axial with the motor axis. 
     
     
         40 . A surface cleaning apparatus comprising:
 a) an air flow passage extending from a dirty air inlet to a clean air outlet;   b) a cyclone positioned in the air flow passage and having a cyclone air inlet, a cyclone air outlet and a cyclone axis;   c) a suction motor positioned in the air flow passage and having a longitudinally extending motor axis; and,   d) a filter assembly downstream of the cyclone air outlet and upstream of the suction motor, the filter assembly comprising a longitudinally extending first filter media configured as a hollow body and having a filter axis, an outer upstream surface, an inner downstream surface positioned transversely inwardly from the outer upstream surface and a transversely positioned inner longitudinally extending downstream air flow passage   wherein the longitudinally extending filter axis is generally parallel to the motor axis and intersects the suction motor.   
     
     
         41 . The surface cleaning apparatus of  claim 40  wherein the longitudinally extending first filter media is substantially annular. 
     
     
         42 . The surface cleaning apparatus of  claim 40  wherein the inner downstream surface is circular in transverse section. 
     
     
         43 . The surface cleaning apparatus of  claim 40  wherein the longitudinally extending filter axis is coaxial with the motor axis. 
     
     
         44 . The surface cleaning apparatus of  claim 40  wherein the longitudinally extending first filter media comprises a foam filter. 
     
     
         45 . The surface cleaning apparatus of  claim 40  further comprising a secondary filter provided co-extensively with the longitudinally extending first filter media. 
     
     
         46 . The surface cleaning apparatus of  claim 45  wherein the secondary filter is provided on one of the outer upstream surface and the inner downstream surface of the longitudinally extending first filter media. 
     
     
         47 . The surface cleaning apparatus of  claim 46  wherein the secondary filter is provided on the inner downstream surface of the longitudinally extending first filter media. 
     
     
         48 . The surface cleaning apparatus of  claim 47  wherein the secondary filter filters finer particulate matter than the longitudinally extending first filter media. 
     
     
         49 . The surface cleaning apparatus of  claim 40  further comprising a secondary filter downstream of the longitudinally extending first filter media and coaxial therewith. 
     
     
         50 . The surface cleaning apparatus of  claim 49  wherein the secondary filter filters finer particulate matter than the longitudinally extending first filter media. 
     
     
         51 . The surface cleaning apparatus of  claim 40  wherein the cyclone axis is generally parallel to the motor axis. 
     
     
         52 . The surface cleaning apparatus of  claim 51  wherein the cyclone axis is generally co-axial with the motor axis.