Cleaning device for cleaning a surface comprising a brush and a squeegee element

Abstract

The present invention relates to a cleaning device for cleaning a surface ( 20 ), comprising: —a nozzle arrangement ( 10 ) that comprises i) a brush ( 12 ) rotatable about a brush axis ( 14 ), said brush ( 12 ) being provided with flexible brush elements ( 16 ) having tip portions ( 18 ) for contacting the surface to be cleaned ( 20 ) and picking up dirt particles ( 22 ) and liquid ( 24 ) from the surface ( 20 ) during a pick-up period when the brush elements ( 16 ) contact the surface ( 20 ) during the rotation of the brush ( 12 ), wherein a linear mass density of a plurality of the brush elements ( 16 ) is, at least at the tip portions ( 18 ), lower than 150 g per 10 km, and ii) a single squeegee element ( 32 ) for pushing or wiping dirt particles ( 22 ) and liquid ( 24 ) across or off the surface to be cleaned ( 20 ) during movement of the cleaning device ( 100 ), said squeegee element ( 32 ) being spaced apart from the brush ( 12 ) and extending substantially along a longitudinal direction ( 48 ) being substantially parallel to the brush axis ( 14 ), wherein a suction area ( 34 ) is defined within the nozzle arrangement ( 10 ) between the squeegee element ( 32 ) and the brush ( 12 ), —a drive means for driving the brush ( 12 ) in rotation, wherein the drive means are adapted to realize a centrifugal acceleration at the tip portions ( 18 ) which is, in particular during a dirt release period when the brush elements ( 16 ) are free from contact to the surface ( 20 ) during rotation of the brush ( 12 ), at least 3,000 m/s 2, and —a vacuum aggregate ( 38 ) for generating an under-pressure in the suction area ( 34 ) for ingesting dirt particles ( 22 ) and liquid ( 24 ).

1 - 15 . (canceled) 
     
     
         16 . A nozzle arrangement for a hard floor cleaning device, comprising:
 a single rotary brush rotatable about a brush axis, said brush being provided with flexible brush elements having tip portions for contacting the surface to be cleaned and picking up dirt particles and liquid from the surface during a pick-up period when the brush elements contact the surface during the rotation of the brush, wherein a linear mass density of a plurality of the brush elements is, at least at the tip portions, lower than 150 g per 10 km, and   a single squeegee element for pushing or wiping dirt particles and liquid across or off the surface to be cleaned during movement of the cleaning device, said squeegee element being spaced apart from the brush and extending substantially along a longitudinal direction being substantially parallel to the brush axis, wherein a suction area is defined within the nozzle arrangement between the squeegee element and the brush, and   a drive means for driving the brush in rotation, wherein the drive means are adapted to realize a centrifugal acceleration at the tip portions which is, in particular during a dirt release period when the brush elements are free from contact to the surface during rotation of the brush, at least 3,000 m/s 2 .   
     
     
         17 . The nozzle arrangement as claimed in claim  1 , wherein the brush axis and/or the longitudinal direction of the squeegee element is arranged transverse, preferably perpendicular to the intended direction of movement of the cleaning device. 
     
     
         18 . The nozzle arrangement as claimed in claim  1 , wherein said squeegee element comprises switching means for switching the squeegee element to a closed position, in which the squeegee element is adapted to push or wipe dirt particles and liquid across or off the surface to be cleaned, when the cleaning device is moved on the surface in a forward direction, in which the squeegee element is, seen in the direction of movement of the cleaning device, located behind the brush, and for switching the squeegee element to an open position, in which dirt particles and liquid from the surface to be cleaned can enter the suction area through an opening between the squeegee element and said surface, when the cleaning device is moved on the surface in a backward direction, in which the squeegee element is, seen in the direction of movement of the cleaning device, located in front of the brush. 
     
     
         19 . The nozzle arrangement as claimed in claim  1 , wherein the nozzle arrangement comprises a nozzle housing that at least partly surrounds the brush and wherein the squeegee element is attached to said housing. 
     
     
         20 . The nozzle arrangement as claimed in claim  1 , further comprising positioning means for positioning the brush axis at a distance to the surface to be cleaned that is smaller than the radius of the brush with fully outstretched brush elements to realize an indentation of the brush part contacting the surface during operation, which indentation is in a range from 2% to 12% of the brush diameter. 
     
     
         21 . The nozzle arrangement as claimed in claim  1 , wherein a packing density of the brush elements is at least 30 tufts of brush elements per cm 2 , and wherein a number of brush elements per tuft is at least 500. 
     
     
         22 . The nozzle arrangement as claimed in claim  1 , wherein a linear mass density of a majority of a total number of the brush elements is, at least at the tip portions, lower than 20 g per 10 km. 
     
     
         23 . The nozzle arrangement as claimed in claim  1 , wherein the drive means are adapted to realize an angular velocity of the brush which is in a range of 3,000 to 15,000 revolutions per minute, more preferably in a range of 5,000 to 8,000 revolutions per minute, during operation of the device. 
     
     
         24 . The nozzle arrangement as claimed in claim  1 , wherein the brush has a diameter which is in a range of 10 to 100 mm, more preferably in a range of 20 to 80 mm, most preferably in a range of 35 to 50 mm, when the brush elements are in a fully outstretched condition, and wherein the length of the brush elements is in a range of Ito 20 mm, preferably in a range of 8 to 12 mm, when the brush elements are in a fully outstretched condition. 
     
     
         25 . The nozzle arrangement as claimed in claim  1 , comprising means for supplying a liquid to the brush at a rate which is lower than 6 ml per minute per cm of a width of the brush in which the brush axis is extending. 
     
     
         26 . The nozzle arrangement as claimed in claim  1 , comprising means for generating an airflow on a brush's side facing away from the squeegee element, in an area where the brush contacts the surface to be cleaned during operation of the device. 
     
     
         27 . The nozzle arrangement as claimed in claim  1 , comprising a deflector for contacting the brush at a location, seen in direction of rotation, before the location where the brush contacts the surface to be cleaned during rotation. 
     
     
         28 . The nozzle arrangement as claimed in claim  1 , wherein the brush is a spiraled brush having tufts arranged on the periphery of the brush in a spiral-like pattern. 
     
     
         29 . Hard floor cleaning device for cleaning a surface comprising:
 the nozzle arrangement as claimed in claim  1 , and   a vacuum aggregate for generating an under-pressure in the suction area for ingesting dirt particles and liquid.   
     
     
         30 . The hard floor cleaning device as claimed in claim  14 , wherein said under-pressure generated by the vacuum aggregate is in a range of 3 to 70 mbar, preferably in a range of 4 to 50 mbar, most preferably in a range of 5 to 30 mbar.