Abstract:
A portable surface treating apparatus includes a shaft part ( 12 ) and a frame structure ( 22 ). The shaft part ( 12 ) has a handle part ( 13 ) that is capable of guiding the apparatus on the surface to be treated. The frame structure ( 22 ) has several rolls ( 29, 31 ) about which an endless conveyor belt ( 27 ) for liquid and dirt particles is arranged. A portion of the belt between the rolls is placed such that it is mainly parallel to the surface.

Description:
This application claims the benefit of International Application Number PCT/SE03/00915, which was published in English on Dec. 24, 2003. 
     BACKGROUND OF THE INVENTION 
     1. FIELD OF INVENTION 
     This invention relates to a portable surface treating apparatus comprising a shaft part with a handle part by means of which the apparatus can be guided on the surface to be cleaned and a frame structure having several rolls about which an endless conveyor belt for liquid and dirt particles is arranged. 
     2. DESCRIPTION OF RELATED ART 
     Apparatuses of the type mentioned above are previously known, see U.S. Pat. No. 4,926,515, and are used for wet cleaning of, for instance, floor surfaces. These apparatuses also comprise a container for dispensing cleaning liquid to the surface and a container for collecting dirty liquid which is picked up from the surface. The belt consists of a liquid absorbing material conveying the dirty liquid from the surface to the last mentioned container in which the liquid is removed from the conveyor belt by a squeezing means. This type of apparatus has, however, the drawback that the belt abuts the surface by line contact, which means that the absorption capacity decreases since the belt is squeezed by means of the compression forces when resting against the surface. Moreover, the apparatus can be hard to handle and guide because the driving motion of the belt is accomplished by means of manual measurements from the operator, i.e. by friction engagement between the belt and the surface. 
     It is also previously known, see U.S. Pat. No. 4,875,246, to use similar surface treatment apparatuses driven by electric motors and comprising a roll having an exterior surface of liquid absorbing material. The roll is driven by the electric motor and conveys the dirty liquid from the surface to a collecting container. Also, this apparatus has the drawbacks that are linked to line contact with the surface and the result is that too much water remains on the surface, which means long drying periods after the treatment. 
     Further, there are floor scrubbing machines having endless belts that operate with area contact, see for instance DE 10025446 A1, U.S. Pat. No. 3,945,078, and WO 02/39869 A1. Since these devices solely are provided with means for squeezing out the liquid from the belt, there is a considerable risk that dirt particles which are conveyed by the belt are not removed from the belt together with the liquid, but instead are re-deposited on the floor surface. 
     The purpose of this invention is to achieve a portable surface treating apparatus that conveys liquid as well as dirt particles from the surface to the collecting container and that does not have the drawbacks mentioned above. The apparatus is simple to handle and easy to guide at the same time as it safeguards a high degree of liquid removal from the surface such that it gets dry quickly. This is achieved by means of a device having the characteristics mentioned in the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       An embodiment of the invention will now be described with reference to the accompanying drawings in which:  FIG. 1  is a perspective view of the surface treatment apparatus in question,  FIG. 2  is a perspective view of the lower portion of the apparatus without the conveyor belt that normally is arranged on it,  FIG. 3  is a vertical section through a part of said lower portion,  FIG. 4  is a plan view of a container part which is removably arranged at the rear part of the lower portion, and  FIGS. 5 and 6  are the same views as  FIG. 4 , but the parts are partly demounted. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As appears from  FIG. 1 , the surface treatment apparatus comprises an upper part  10  and a lower part  11 . The upper part comprises a shaft  12  with a handle  13 . The lower end of the shaft continues via a link connection  14  into a bracket  15  in which the lower part  11  is removably secured in a manner not shown in detail. The shaft  12  supports two removably arranged containers, a first container  16  for a cleaning liquid and a second container for dirty liquid  17 . The upper part  10  also is provided with a control panel  18  arranged close to the handle and by means of which the different functions of the apparatus can be controlled. The control panel is connected to an electric circuit, not shown, that is fed from mains supply via a cable  19 . If desired, this current source may of course be replaced by a battery source. 
     The first container has a fill opening and one outlet, not shown, which is placed at the bottom and to which a valve is connected. The valve can be opened from the control panel  18  in order to let out the cleaning liquid through a hose  20  that is connected to a nozzle, not shown, at the bottom side of the bracket  15 . The other container  17  for dirty liquid is by means of a hose  21  connected to the lower part  11  in a way that will be described below. 
     The lower part  11  comprises an elongated, slightly V-shaped, box shaped frame structure  22  comprising a front and a rear part  22   a  and  22   b , respectively, that are turnably connected to one another about an axis  23 . The frame structure  22  comprises two side walls  24  and an upper and a lower wall  25  and  26 , respectively, that constitute flat elongated surfaces against which the inner side of an endless conveyor belt  27  rests. The conveyor belt comprises a supporting layer  27   a  on which a soft liquid absorbing layer, for instance a so called micro fibre layer,  27   b  is arranged. The supporting layer has a central ridge  27   c  directed inwardly and whose purpose will be explained below. 
     The front and rear part  22   a  and  22   b , respectively, of the frame structure can, as has been described above, be turned with respect to one another between a first position where the parts are aligned with respect to one another and where the front part  22   a  is prevented from turning upwards with respect to the rear part  22   b  by means of co-operating abutting surfaces  28  to a second position where the front part  22   a  is folded down with respect to the rear part  22   b  such that the conveyor belt can be removed from the frame structure. 
     The frame structure  22  also supports a front roll  29  which is freely rotatable about a shaft  30  and a rear roll  31  rotatably arranged about a shaft  32 . The frame structure  22  as well as the rolls  29 ,  31  are provided with central grooves  33 ,  34 ,  35  in which the ridge  27   c  of the belt runs. The frame structure  22  also encloses an electric motor  36  having a drive shaft  37  that via a belt transmission  38  transmits the rotation motion of the drive shaft to the rear roll  31 . The frame structure  22  at its rear end also supports a container part  39  which is removably arranged at the frame structure  22  by means of two snap tongues  40  arranged one at each side of the frame structure. 
     The container part  39  constitutes a container with a bottom  39   a , side walls  39   b , a front wall  39   c  and a rear wall  39   d . The front wall  39   c  is shaped as a part of the exterior surface of a horizontal cylinder and is placed such that the distance between the outside of the wall  39   c  and the part of the conveyor belt  27  that rests against the roll  31  is successively decreased when the conveyor belt moves upwards in  FIG. 3  together with the roll. The front wall is tapered such that the liquid following the belt will flow downwards, inwards towards the container. The bottom  39   a  of the container supports a removable scratching plate  41  which in section is L-shaped and which has a first leg  4   a  whose lower end is inserted between two dowels  42  such that the scratching plate can be turned about this end. The other leg  41   b  of the scratching plate has several openings  41   c  and the scratching plate  41  is additionally shaped such that the liquid which is present in the container can freely flow about or through it. The free end of the other leg  41   b of the scratching plate is by means of spring pressure arranged to abut the conveyor belt  27  above the front container wall  39   c  the spring force being achieved by means of an L-shaped spring plate  43  that is connected to the first leg  41   a  and having an extending leg portion  43   a arranged to rest on the bottom  39   a  of the container. 
     The container part  39  encloses a removable pump housing  44  that is provided with a membrane pump  45  having an inlet  46  facing the bottom and an outlet, not shown, that via a check valve  47  is connected to a nipple on which the hose  21  is applied. The front part of the pump housing  44  has a flange  48  that is directed downwards and that rests on the leg  43   a  of the spring plate  43  and normally pushes it against the bottom  39   a  of the container. The pump housing also has a sleeve  49  that is arranged centrally and that co-operates with a bead  50  arranged at the bottom of the container in order to place the pump housing into the right position in the container part  39 . Between the bottom side of the pump housing  44  and the bottom  39   a  of the container (and outside the inlet  46  of the pump and the bead  50 ) a porous filter mesh  51  is inserted. 
     The container  39  is partly covered by a rocker arm  52  having two dowels  53  that are supported for turning motion at the side walls  39   b  of the container. The front part of the rocker arm  52  supports a freely rotating roll  54  that abuts the conveyor belt  27  at its entire width. The motion of the conveyor belt  27  due to friction engagement creates a rotating motion of the roll  54 . The roll  54  is eccentrically supported by the rocker arm  52  by means of a dowel  55  arranged at each side of the roll. The rear part of the rocker arm  52  rests against a push rod  56  that is surrounded by a coil spring  57 . The push rod  56  serves as an activation means for the membrane pump  45 . Thus, the tilting motion of the rocker arm  52  created by the roll  54  in turn creates a to-and-fro motion of the push rod  56 , which then activates the membrane pump  45 . 
     The container part  39  also has a channel  58  that is placed at each side of the rear roll  31  the channels extending forwards, upwards from the container at each side wall  39   b  such that liquid flowing from the belt drops down into the channel and is transported to the container. 
     The device operates and is used in the following manner. The operator removes the first container  16  from the apparatus and the hose  20  and fills it with a suitable cleaning agent after which the container is again replaced on the apparatus. Then the operator starts the motor  36  by means of the control panel  18  and simultaneously applies cleaning liquid on the belt by means of the valve that is built into the container and via the hose  20  and the nozzles arranged below the bracket  15 . The drive shaft  37  of the electric motor thereby transfers the drive force via the gear  38  to the rear roll  31  that drives the conveyor belt  27  counter-clockwise in  FIG. 2  about the front roller  29  the conveyor belt being centered because its elongated ridge  27   c  runs in the grooves  33 ,  34  and  35 . Hence, cleaning liquid will be applied on the surface by means of the conveyor belt  27  at the same time as dirt particles together with the liquid is transported up through the gradually narrowing gap between the conveyor belt and the front wall  39   c . When the conveyor belt reaches up above the front wall  39   c  dirt particles and a part of the liquid will be removed from the belt by means of the portion of the leg  41   b  of the spring loaded scratching plate  41  that abuts the conveyor belt. When the belt continues to move upwards about the roll  31  the belt will get in touch with the roll  54  that then squeezes out the liquid which is contained in the belt. The major part of the liquid that is squeezed out flows down through the openings  41   c  in the scratching plate  41  and brings the dirt particles to the container whereas liquid also is collected from the edges of the belt and flows down into the container via the channels  58 . Simultaneously the membrane pump  45  will operate since the roll  54 , that is supported eccentrically and that is in friction engagement with the belt, rotates and thereby achieves a tilting motion of the rocker arm  52  that acts on the pump via the push rod  56 . Thus, the liquid which is collected in the container flows through the filter  51  to the pump inlet  46  from which it flows further through the pump  45  and the check valve  47  through the hose  21  up to the dirty liquid container  17 . When the cleaning has been finished the dirty liquid container  17  is removed and emptied of its content. If desired the conveyor belt  27  can be removed by folding down the front part  22   a  of the frame structure  22  with respect to the rear part  22   b . After cleaning or replacing the belt the frame structure can be moved back to its normal position by again folding up the front part  22   a  such that the abutting surfaces  28  will touch each other. 
     It should in this connection be mentioned that the device is designed such that the components that are involved easily can be demounted and be cleaned. Thus, the container part  39  can easily be removed from the frame structure  22  by acting on the snap tongues  40 . When a locking means, not shown, has been released, the rocker arm  52 , the pump housing  44  with the check valve  47 , the filter mesh  51  and the scratching plate  41  with the spring plate  43  can successively be lifted out from the container. 
     The apparatus according to the invention is very easy to handle since the electric motor pulls the apparatus in the forward direction which means that the operator easily can guide the apparatus in the desired direction by means of minimal manual efforts.