Dirt separator

Abstract

A dirt separator for separating dirt from an airflow includes an air inlet, an air outlet, and a filter located between the air inlet and the air outlet. The filter includes a first face, a second face, and a through-hole extending between the first and second faces. The filter includes a chamfer extending only partially around a periphery of the through-hole on the first face.

1 . A dirt separator for separating dirt from an airflow, the dirt separator comprising an air inlet, an air outlet, and a filter located between the air inlet and the air outlet, the filter comprising a first face, a second face, and a through-hole extending between the first and second faces, wherein the filter comprises a chamfer extending only partially around a periphery of the through-hole on the first face. 
     
     
         2 . A dirt separator as claimed in  claim 1 , wherein the chamfer extends around no more than 75%, no more than 60%, or no more than 50% of the periphery of the through-hole on the first face. 
     
     
         3 . A dirt separator as claimed in  claim 1 , wherein the through-hole is substantially circular in cross-section, and the chamfer extends around no more than 180° of the periphery of the through-hole on the first face. 
     
     
         4 . A dirt separator as claimed in  claim 1 , wherein the filter comprises a further chamfer extending only partially around a further periphery of the through-hole on the second face. 
     
     
         5 . A dirt separator as claimed in  claim 4 , wherein the further chamfer extends around no more than 75%, no more than 60%, or no more than 50% of the further periphery of the through-hole on the second face. 
     
     
         6 . A dirt separator as claimed in  claim 4 , wherein the through-hole is substantially circular in cross-section, and the further chamfer extends around no more than 180° of the further periphery of the through-hole on the second face. 
     
     
         7 . A dirt separator as claimed in  claim 4 , wherein the chamfer and the further chamfer are located on diametrically opposite sides of the respective periphery and further periphery of the through-hole. 
     
     
         8 . A dirt separator as claimed in  claim 7 , wherein:
 the through-hole comprises a central axis extending between the first and second faces;   the periphery of the through-hole on the first face comprises a first side and a second side relative to an axis orthogonal to the central axis;   the further periphery of the through-hole on the second face comprises a third side corresponding to the first side, and a fourth side corresponding to the second side;   the chamfer extends around the first side of the periphery of the through-hole on the first face; and   the further chamfer extends around the fourth side of the further periphery of the through-hole on the second face.   
     
     
         9 . A dirt separator as claimed in  claim 1 , wherein the dirt separator comprises a cyclonic separator. 
     
     
         10 . A dirt separator as claimed in  claim 1 , wherein the dirt separator comprises a wiping mechanism for wiping the first face. 
     
     
         11 . A dirt separator as claimed in  claim 10 , wherein the wiping mechanism comprises a blade movable relative to the first face from a first position to a second position, and the chamfer is located such that the blade passes over a portion of the periphery of the through-hole that does not comprise the chamfer before passing over the chamfer when moving from the first position to the second position. 
     
     
         12 . A dirt separator as claimed in  claim 11 , wherein a depth of the chamfer decreases in a direction from the first position to the second position. 
     
     
         13 . A dirt separator as claimed in  claim 1 , wherein the through-hole comprises a first width, the chamfer comprises a second width less than the first width, and a ratio of the second width to the first width is in the range of 0.1 to 0.5. 
     
     
         14 . A dirt separator as claimed in  claim 13 , wherein the ratio of the second width to the first width is in the region of 0.3. 
     
     
         15 . A dirt separator as claimed in  claim 1 , wherein the through-hole is generally circular in cross-section, and comprises a diameter in the range of 200 μm to 600 μm. 
     
     
         16 . A dirt separator as claimed in  claim 1 , wherein the through-hole comprises a first maximal depth between the first and second faces, the chamfer comprises a second maximal depth less than the first maximal depth, and a ratio of the second maximal depth to the first maximal depth is in the range of 0.4 to 0.6. 
     
     
         17 . A dirt separator as claimed in  claim 1 , wherein the chamfer is formed on the filter by chemical etching. 
     
     
         18 . A dirt separator as claimed in  claim 1 , wherein the filter comprises a plurality of through-holes, and a plurality of chamfers each extending only partially about a corresponding periphery of a through-hole on the first face. 
     
     
         19 . A filter for a dirt separator, the filter comprising a first face, a second face, and a through-hole extending between the first and second faces, wherein the filter comprises a chamfer extending only partially around a periphery of the through-hole on the first face. 
     
     
         20 . A vacuum cleaner comprising a dirt separator as claimed in  claim 1 .