Filter cleaning unit, vacuum cleaner and method for cleaning a filter in a vacuum cleaner

16:

• A filter cleaning unit for a vacuum cleaner, the vacuum cleaner having a turbine for generating a suction air flow and a filter for filtering the suction air flow, a suction channel being provided between the turbine and the filter, wherein the suction channel is dividable by a separator into at least a first suction part channel and a second suction part channel, the filter cleaning unit comprising:
• at least one valve unit for opening or closing the first and second suction part channels.

17:

• The filter cleaning unit as recited in claim 16 wherein the filter cleaning unit opens or closes the first and second suction part channels alternately so that in each case, one of the first and second suction part channels is open and the other of the first and second suction part channels is closed.

18:

• The filter cleaning unit recited in claim 16 wherein during suction operation of the vacuum cleaner, the second suction part channel is substantially open while the first suction part channel is substantially closed.

19:

• The filter cleaning unit as recited in claim 16 wherein the at least one valve unit is formed by a first individual valve and a second individual valve, wherein the first and second individual valves are controllable independently of one another.

20:

• The filter cleaning unit as recited in claim 16 wherein the at least one valve unit is formed by a first flat element and a second flat element connected together via a common shaft.

21:

• The filter cleaning unit as recited in claim 16 wherein the at least one valve unit is formed by an individual valve having at least a first position and a second position, and wherein the individual valve in the first position opens the first suction part channel and closes the second suction part channel, and wherein the individual valve in the second position opens the second suction part channel and closes the first suction part channel.

22:

• The filter cleaning unit as recited in claim 16 further comprising a piston element movable from a rest position in the direction of the filter of the filter cleaning unit by introduction of ambient air through an external opening of the filter cleaning unit.

23:

• The filter cleaning unit as recited in claim 22 wherein the external opening of the filter cleaning unit has an external valve configured to open or close the external opening of the filter cleaning unit.

24:

• The filter cleaning unit as recited in claim 22 wherein the piston element is returned to the rest position by an actuation of the valve unit.

25:

• The filter cleaning unit as recited in claim 22 wherein the piston element is returned to the rest position by an opening of the first suction part channel and by a closing of the second suction part channel.

26:

• The filter cleaning unit as recited in claim 22 further comprising a magnet configured to hold the piston element in the rest position.

27:

• A vacuum cleaner comprising the filter cleaning unit as recited in claim 15.

28:

• A construction site vacuum cleaner comprising the filter cleaning unit as recited in claim 15.

30:

• The method as recited in claim 29 wherein the vacuum cleaner has a piston element having a rest position during suction operation of the vacuum cleaner, and transferable from the rest position to a filter cleaning position by inflowing ambient air, wherein movement of the piston element causes the indirect cleaning pulse.

31:

• The method as recited in claim 30 wherein the piston element is returnable from the filter cleaning position to the rest position by an opening of the first suction part channel and by a closing of the second suction part channel.