Wet vacuum cleaner, a cleaning tray and a cleaning method

Abstract

The invention provides a cleaning tray for a wet floor cleaner, for receiving a head of the wet floor cleaner. The cleaning tray has at least one brush channels for receiving a bottom portion of an outer circumference of a roller brush. At least one raised projection is positioned along the brush channel having an upstream ramp surface and a steeper downstream ramp surface. The projection adds turbulence for improving the cleaning results as well as enabling control of the flow of cleaning liquid around the brush and the cleaning tray, to ensure full soaking of the roller brush as well as cleaning of all of the area of the cleaning tray itself. The invention also provides a cleaning method which may use the cleaning tray.

1 . A cleaning tray of a wet floor cleaner, adapted to receive a head of the wet floor cleaner, the head comprising a roller brush, the cleaning tray comprising:
 a base for supporting the head;   a brush channel formed in the base for receiving a bottom portion of an outer circumference of the roller brush;   at least one raised projection positioned along the brush channel which is for projecting into the roller brush when the cleaning tray is used, wherein the raised projection comprises an upstream ramp surface positioned such that the outer circumference of the roller brush rides up the upstream ramp surface when rotated and a downstream ramp surface, wherein the downstream ramp surface is steeper than the upstream ramp surface; and   a suction area faced by the downstream ramp surface.   
     
     
         2 . The cleaning tray of  claim 1 , comprising a set of raised projections each having an upstream ramp surface and a downstream ramp surface. 
     
     
         3 . The cleaning tray of  claim 2 , wherein the raised projection or each of the raised projection has:
 a height in the range 1 mm to 10 mm; and/or   a length, parallel to a length of the brush channels, in the range 1 mm to 50 mm.   
     
     
         4 . The cleaning tray of  claim 2 , wherein the raised projection or each of the raised projection has an apex at the junction between the upstream and downstream ramp surfaces, with an angle of 90 degrees or more. 
     
     
         5 . The cleaning tray of  claim 4 , wherein the apex has a radius of curvature of less than 2 mm. 
     
     
         6 . The cleaning tray of  claim 1 , wherein the brush channel comprises a set of two or more raised projections, and wherein there are at least two different shapes of raised projection within the set. 
     
     
         7 . The cleaning tray of  claim 1 , further comprising, in the brush channels, a flow guide which provides a flow path across the brush channel to the suction area. 
     
     
         8 . The cleaning tray of  claim 7 , wherein the flow guide comprises two lateral side projections which become closer together along the flow path. 
     
     
         9 . The cleaning tray of  claim 8 , wherein the two lateral side projections form part of a V-shape with an apex angle in the range 40 to 120 degrees. 
     
     
         10 . The cleaning tray of  claim 1 , comprising opposite side walls, wherein one of the side walls has an opening through which the roller brush is received laterally parallel to its axes of rotation. 
     
     
         11 . The cleaning tray of  claim 1 , adapted to receive a head of a wet floor cleaner which comprises a pair of roller brushes, wherein the cleaning tray comprises a pair of brush channels, and wherein the suction area is in between the pair of brush channels. 
     
     
         12 . A wet floor cleaner comprising:
 a cleaning head comprising:
 a housing; 
 at least one rotary brush extending across a width of the housing; and 
 a suction channel for delivering suction to at least a space adjacent the at least one rotary brush; 
 a pump for delivering suction to the suction channel of the cleaning head; 
 a delivery system for delivering cleaning liquid to the cleaning head; and 
 the cleaning tray of  claim 1 . 
   
     
     
         13 . A method of cleaning a roller brush of a cleaning head of a wet floor cleaner, when the cleaning head is fitted to a cleaning tray, the cleaning head comprising at least one rotary brush and suction channel for delivering suction to at least a space adjacent the at least one rotary brush, the method comprising:
 in a start cycle:
 delivering a relatively large volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed with no delivered suction; and 
 delivering a relatively small volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively fast rotational speed and applying a first level of suction; 
   in a middle cycle:
 delivering a relatively large volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed with no delivered suction; 
 delivering a relatively small volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively fast rotational speed with no delivered suction; and 
 delivering a relatively small volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively fast rotational speed and applying a second level of suction lower than the first level of suction; and 
   in an end cycle:
 delivering a maximum volume of cleaning liquid to the cleaning head and driving the roller brush at a relatively slow rotational speed with no delivered suction; and 
 driving the roller brush at a relatively fast rotational speed and applying the suction with no delivered cleaning liquid. 
   
     
     
         14 . The method of  claim 13 , wherein the last step of the end cycle comprises driving the roller brush at a relatively fast rotational speed and applying the second level of suction and then the first level of suction with no delivered cleaning liquid. 
     
     
         15 . The method of  claim 13  applied with the cleaning head fitted to a cleaning tray as claimed in  claim 1 .