Filter cleaning for dirt suction devices comprising an external fan

Abstract

A dirt suction device comprises at least two filters ( 3, 4 ) which are arranged on/in a dirt suction device housing (I), are affected by an air stream from a fan ( 21 ), and include valves ( 26 - 34 ) for separately controlling the cleaning action of the filter, wherein during normal operation, the dirt-laden air stream passes through at least one filter from the untreated air side to the clean air side, and at least one of the valves is associated with each of the at least two filters, said valve switching over in the cleaning position such that the air stream in the filter is reversed and the dirt particles adhering to the untreated air side are removed, wherein the fan of the dirt suction device is arranged outside the dirt suction device housing.

1 - 10 . (canceled) 
     
     
         11 . A dirt suction device having a valve control for cleaning at least one filter, in which during the cleaning action at least one valve situated in the suction opening of the filter to be cleaned is closed, and at least one valve used for cleaning is opened, wherein the valve control comprises:
 an upper valve seat and a lower valve seat,   at least one activating member,   a valve rod activated by the at least one activating member and extending through the upper and lower valve seats,   an upper and a lower valve plate fixedly connected to the valve rod and linearly movable with the valve rod, the valve plates engaging with or disengaging from the upper and lower valve seats to define closed and open positions of the valve plates, respectively, and   at least one spring biasing the lower valve plate toward the closed position.   
     
     
         12 . The dirt suction device according to  claim 11 , wherein several filter cartridges or flat filters can be controlled separately from one another by the valve control. 
     
     
         11 . The dirt suction device according to  claim 11 , further comprising an intermediate chamber defined between the valve and the suction chamber, wherein the at least one activating member comprises at least one solenoid, and the valve control is configured such that the at least one solenoid is without current and the controlled valve rod corresponding thereto is disposed in the open position solely by its own weight and the pressure difference between the intermediate chamber and the suction chamber. 
     
     
         14 . The dirt suction device according to  claim 11 , wherein by switching the valve plates cleaning air enters the at least one filter through a cleaning opening.