SURFACE CLEANING DEVICE AND CLEANING PROCESS FOR CLEANING A PLANAR FLOOR SURFACE

Abstract

Surface cleaning device for cleaning an floor surface comprising an inner space forming casing and a liquid dispenser positioned in the inner space. The liquid dispenser 3 comprises a motor driven rotor shaft which defines an axis of rotation. Rotor arms extend radially away from a rotor shaft. Each rotor arm comprises a blade to thrust a volume of liquid medium away from the inner space in a driving direction towards a casing outlet. The liquid dispenser comprises at least one nozzle for jetting a stream of liquid onto the floor surface. The at least one nozzle has a central axis which is inclined positioned in a forward direction with respect to the driving direction under an angle of inclination with respect to the axis of rotation.

Claims

1. Surface cleaning device for cleaning a floor surface which surface cleaning device comprises: a casing and a liquid dispenser, wherein the casing has a circumferential casing wall and a casing top wall which form an inner space, wherein the casing has a casing outlet for discharging a volume of liquid medium away from the inner space, wherein the liquid dispenser is positioned inside the inner space and arranged to dispense a liquid medium onto the floor surface, and wherein the liquid dispenser comprises: a rotor including a rotor shaft which defines an axis of rotation and including at least one rotor arm which extends radially away from the rotor shaft; a motor for rotationally driving the rotor in a driving direction about the axis of rotation; at least one blade connected to the at least one rotor arm which blade has a blade face to thrust a volume of liquid medium during a rotation of the rotor from the inner space in the driving direction towards the casing outlet; and at least one nozzle connected to the at least one rotor arm for jetting a stream of liquid onto the floor surface, wherein the at least one nozzle has a central axis which is inclined positioned in a forward direction with respect to the driving direction of the rotor under an acute angle of inclination with respect to the axis of rotation, such that in operation a liquid stream is jetted onto the floor surface, wherein the liquid stream is directed forwardly with respect to the driving direction of the rotor.

2. Surface cleaning device according to claim 1, wherein the angle of inclination is at least 5, in particular at most 50.

3. Surface cleaning device according to claim 1, wherein all nozzles are oriented under the same angle of inclination.

4. Surface cleaning device according to claim 1, wherein the at least one nozzle is positioned behind a blade which blade and nozzle are connected to the same rotor arm, such that the at least one nozzle isseen in a frontal projection in the driving directionfully shielded by the blade.

5. Surface cleaning device according to claim 1, wherein the rotor comprises a plurality of rotor arms, wherein each rotor arm is provided with a blade.

6. Surface cleaning device according to claim 5, wherein the rotor comprises at least one rotor arm which is provided with a blade and is free of a nozzle, which at least one rotor arm is a so-called blade arm, wherein, in particular, at least half of the amount of rotor arms is a blade arm.

7. Surface cleaning device according to claim 6, wherein the rotor comprises along its periphery a sequence of rotor arms of alternately a rotor arm with a nozzle, a so-called nozzle arm, and a rotor arm without a nozzle, a so-called blade arm.

8. Surface cleaning device according to claim 5, wherein the rotor comprises a plurality of rotor arms which are spaced in rotational symmetry, in particular in 8-fold rotational symmetry.

9. Surface cleaning device according to claim 1, wherein the rotor comprises an amount of rotor arm pairs, wherein each rotor arm of each rotor arm pair includes a nozzle which is positioned at a same radial distance.

10. Surface cleaning device according to claim 8, wherein the rotor comprises at least a first and second nozzle arm, wherein the first nozzle arm includes a first nozzle which is positioned at a first radius, and wherein the second nozzle arm includes a second nozzle which is positioned at a second radius, wherein the first radius is larger than the second radius.

11. Surface cleaning device according to claim 10, wherein the rotor further comprises at least a third and in particular a fourth nozzle arm, wherein the third nozzle arm includes a third nozzle which is positioned at a third radius, and wherein in particular the fourth nozzle arm includes a fourth nozzle which is positioned at a fourth radius, wherein the third radius is smaller than the first and second radius, and wherein in particular the fourth radius is smaller than the third radius.

12. Surface cleaning device according to claim 1, wherein each nozzle arm is provided with a single nozzle.

13. Surface cleaning device according to claim 1, wherein each blade face is positioned under a blade angle of at most 50 with respect to the axis of rotation, such that in operation the blade exerts a lifting thrust on a volume of liquid medium.

14. Surface cleaning device according to claim 1, wherein the surface cleaning device is a surface cleaning device configured to clean a planar surface with an open structure, in particular to clean a sportsfield.

15. Surface cleaning device according to claim 14, wherein the surface cleaning device is a sportsfield cleaning device.

16. Vehicle, wherein the vehicle comprises a surface cleaning device according to claim 1.

17. Cleaning process for cleaning a planar floor surface, wherein use made of a surface cleaning device according to claim 1 comprising: placing the surface cleaning device onto the floor surface which has to be cleaned; supplying liquid medium from a liquid feed supply; moving the surface cleaning device across the floor surface; operating the liquid dispenser of the surface cleaning device by rotationally driving the rotor in a driving direction; jetting a liquid stream onto the floor surface, wherein the liquid stream is under an acute angle of inclination with respect to an axis of rotation and directed forwardly with respect to the driving direction of the rotor.

Description

[0047] The invention will be explained in more detail with reference to the appended drawings. The drawings show a practical embodiment according to the invention, which may not be interpreted as limiting the scope of the invention. Specific features may also be considered apart from the shown embodiment and may be taken into account in a broader context as a delimiting feature, not only for the shown embodiment but as a common feature for all embodiments falling within the scope of the appended claims, in which:

[0048] FIG. 1 shows in a perspective view a surface cleaning device for cleaning an floor surface;

[0049] FIG. 2 shows in a cross sectional top view the cleaning device as shown in FIG. 1;

[0050] FIG. 3 shows in a bottom view a rotor with rotor arms of the cleaning device as shown in FIG. 1;

[0051] FIG. 4 shows in a schematic view an arrangement of an inclined positioned nozzle behind a blade at a rotor arm of the rotor as shown in FIG. 3;

[0052] FIG. 5 shows in a schematic view a cleaning coverage area produced by the rotor as shown in FIG. 3.

[0053] Identical reference signs are used in the drawings to indicate identical or functionally similar components. To facilitate comprehension of the description and of the claims the words vertical, horizontal, longitudinal, cross-sectionalwith reference to the gravityare used in a non-limiting way.

[0054] FIG. 1 shows a surface cleaning device 1 according to the invention. The cleaning device 1 has a framework 10 which is provided with wheels 11 for supporting the cleaning device 1 to an floor surface. The cleaning device 1 may be a stand-alone device. The cleaning device 1 may be pushed by an operator across the floor surface. Alternatively, the cleaning device 1 may be embodied to be carried by a motorised vehicle. The cleaning device may e.g. be arranged connectable to a front loader of a vehicle.

[0055] The cleaning device 1 comprises a housing 12 for housing several machine components. At a lower region, the cleaning device 1 comprises a casing 2. The casing 2 is disc-shaped and is open at a bottom side. The casing 2 has a circumferential casing wall 21 and a casing top wall 22 which form an inner space IS. The casing 2 is arranged for housing a liquid dispenser 3 including a rotor 30 which is positioned inside the inner space IS and further illustrated in FIG. 3.

[0056] The liquid dispenser 3 is fluidly connectable to a feed supply for feeding liquid medium to the liquid dispenser. The feed supply may comprise a feed pump and a feed hose to transfer liquid medium to the liquid dispenser 3. The feed supply may be arranged separate from the surface cleaning device, in which the feed hose of the feed supply is connectable to the liquid dispenser of the surface cleaning device. Alternatively, the feed supply may be arranged on-board of the surface cleaning device.

[0057] FIG. 2 shows a top view of the surface cleaning device 1, in which the housing 12 is omitted to show driving components of the cleaning device 1.

[0058] The casing 2 comprises a casing outlet 23 for discharging a liquid medium away from the inner of the casing 2. The casing outlet 23 is preferably positioned at the circumferential casing wall 21. The casing outlet 23 is oriented in a tangential direction with respect to the circumferential casing wall 21. Alternatively, the casing outlet 23 may be positioned at the casing top wall 22. The casing outlet 23 may be connectable to a filter for separating contaminations from the liquid medium and/or to a reservoir for storing discharged liquid medium.

[0059] As shown in FIG. 2, a motor 33 is connected to the framework 10. The motor 33 is arranged for driving the rotor 30 in a driving direction D, as shown in FIG. 3. The rotor 30 is positioned inside the casing 2. The motor 33 is positioned outside the casing 2. The motor 33 may e.g. be an electric motor including batteries or a fuel motor. Typically, the motor 33 provides a power of about 30-40 HP. In an embodiment in which a vehicle is used to carry the surface cleaning device 1, a motor of such vehicle can be used as the motor 33 for driving the rotor 30 of the cleaning device 1. Herewith, a torque provided by the vehicle can be used for driving the rotor 30 of the liquid dispenser 3.

[0060] The motor 33 is connected by a belt 37 to a rotor shaft 31 of the rotor. The rotor shaft 31 is arranged vertically and defines an axis of rotation A-A. In normal use, the axis of rotation is directed in a vertical direction. The rotor shaft 31 is centrally positioned at the casing top wall 22. The rotor shaft 31 is journaled by a bearing 39 in a casing top wall 22 of the casing 2. The rotor shaft 31 protrudes through the casing top wall 22. At a top side of the casing 2, a rotor drive wheel 38 is connected to an upper portion of the rotor shaft 31. The rotor drive wheel 38 is in engagement with the belt 37 which is operatively connected to the motor 33.

[0061] FIG. 3 shows a bottom view of the cleaning device 1 as shown in FIGS. 1 and 2. The rotor 30 is centrally positioned inside the inner space IS of the casing 2. The inner space is open at a bottom side. The inner space IS is delimited by the circumferential casing wall 21 and the casing top wall 22.

[0062] At least one rotor arm 32 is connected to a lower portion of the rotor shaft 31. Here, a rotor distributor 36 is connected to the bottom portion of the rotor shaft 31, which rotor distributor 36 supports the at least one rotor arm 32. The rotor distributor 36 is positioned in the inner space IS of the casing 2. The at least one rotor arm 32 extends radially away from the rotor shaft 31. The rotor shaft 31 and the rotor distributor 36 include at least one fluid channel for supplying a liquid medium to the at least one rotor arm 32.

[0063] Preferably, an even amount of rotor arms 32 is connected to the rotor shaft 31. The rotor 30 comprises a plurality of rotor arms 32. Here, the rotor 30 comprises sixteen rotor arms 32.

[0064] A blade 34 is connected to the at least one rotor arm 32. Preferably, a blade 34 is connected to each rotor arm 32. The blade 34 comprises a blade face 340 at a front side of the blade 34. The blade face 340 is arranged to thrust during operation a volume of liquid medium from the inner space IS in the driving direction D towards the casing outlet 23. The volume of liquid medium is thrust forwardly. Due to centrifugal forces, the volume of liquid may be thrusted into a tangentially oriented outlet.

[0065] Further, at least one rotor arm 32 comprises a nozzle 35. The nozzle is arranged to jet a stream of liquid medium onto an floor surface FS. The nozzle 35 is in fluid communication connected via the rotor shaft 31 to a feed supply of liquid medium. The rotor arm 32 may comprise an internal fluid channel wherein the nozzle is connectable to an outlet of the fluid channel. Alternatively, the nozzle may externally fluidly connected to the rotor arm 32 by a nozzle conduit.

[0066] A rotor arm 32 which is provided with a nozzle 35 is here also called a nozzle arm 321. A rotor arm 32 which is not provided with a nozzle, but which rotor arm 320 is provided with a blade 34 is called a blade arm 322.

[0067] As shown in FIG. 4, during operation, the nozzle 35 is oriented under an acute angle of inclination with respect to an axis in parallel with the axis of rotation to provide an inclined stream of liquid medium under a high pressure onto the floor surface FS. The nozzle 35 is directed in a forward direction with respect to the driving direction D. The orientation of the nozzle 35 causes the liquid medium to hit the floor surface FS under an incoming acute angle. In comparison with a perpendicular directed nozzle, the inclined orientation of the nozzle 35 provides an improved release of dirt particles from the floor surface. The incoming angle causes a scooping effect. The inclined nozzle effectively hits the dirt particles which may stick to the floor surface FS at a region close to a sticking area and scoopes the dirt particle away.

[0068] Preferably, the incoming angle in between a central axis N-N of the nozzle 35 and the floor surface FS has an angle of inclination which is at least 5. This already provides an improved release of dirt particles from a floor surface. More in particular, the angle of inclination is at least 15 to further improve the release. Preferably, the angle of inclination is at least 30 to increase a release of dirt particles. A major advantage is that the surface cleaning device can be used for cleaning top surfaces of vulnerable floor surfaces, like sportsfields. Advantageously, the in forward direction inclined nozzle may contribute in saving a water volume necessary for the cleaning operation. Additionally, the inclined nozzle allows an increase of running speed of the surface cleaning device 1 when crossing an floor surface to be cleaned. Herewith, a cleaning process can be carried out more quickly. A higher cleaning quality may be achieved and the cleaning process can be performed in a shorter process time.

[0069] In comparison with a perpendicular orientation of a nozzle 35, the acute angle causes a significant portion of the stream of liquid medium to reflect from the floor surface FS in a forward direction with respect to the driving direction D. Particles of dirt which might be captured in orifices of the porousfloor surface are expelled, forced away and released from the floor surface FS. During operation, such a volume V of liquid medium comprising dirt particles will swirl above the floor surface FS in front of a blade face 340. This volume V is then wiped away by the blade 34. The blade face 340 of the blade 34 pushes the volume V away from the inner space IS in the driving direction D towards the casing outlet 23.

[0070] Here, the blade 34 is plate-shaped. The blade 34 may be formed from a flat panel. Here, in particular, the blade face 340 is oriented in a same angle of inclination with respect to the axis of rotation A-A as the nozzle 35. A blade tip 341 is bent forwardly with respect to the blade face 340. Advantageously, the bent provides rigidity to the blade. In particular, the blade face 340 is oriented under an angle of inclination of at least 5, e.g. 15, such that the volume V is slightly lifted, but mainly pushed into the direction of the casing outlet 23. Preferably, the blade face is oriented under an angle of at most 50 to obtain a proper ratio in a lifting and thrusting capacity.

[0071] As shown in FIG. 4, the nozzle 35 is positioned behind the blade 34. The blade 34 and nozzle 35 are mounted to the same rotor arm 32. Seen in a frontal projection of the driving direction D, the nozzle 35 is fully covered by the blade 34. The nozzle 35 does not protrude outside an outer contour of the blade 34. The nozzle 35 is hided behind the blade 34. Herewith, the blade 34 forms a shield for shielding the nozzle 35 during rotation. An abrasive wear of the nozzle 35 is advantageously strongly reduced by the placement of the nozzle 35 right behind blade 34.

[0072] FIG. 3 and corresponding FIG. 5 show a positioning of nozzles 35 at several radii from the axis of rotation A-A. Here, the nozzles are placed at four different radii r1, r2, r3, r4 to increase an area covered by the nozzles during each rotation of the rotor 30. Each nozzle arm supports only a single nozzle 35. The nozzles of several nozzle arms are spaced from each other at a distance of at least 5 cm. In particular, the nozzles are spaced at distance of at least 10 cm. By positioning at least two nozzles 35 at different radii, the area which is covered by the nozzles in each rotation is increased which may further contribute to a shortening of a process time of the cleaning process.

[0073] Thus, the invention provides a cleaning process and surface cleaning device 1 for cleaning an floor surface FS comprising an inner space IS forming casing 2 and a liquid dispenser 3 positioned in the inner space IS. The liquid dispenser 3 comprises a motor driven rotor shaft 31 which defines an axis of rotation. Rotor arms 32 extend radially away from a rotor shaft 31. Each rotor arm 32 comprises a blade 34 to thrust a volume V of liquid medium away from the inner space IS in a driving direction D towards a casing outlet 23. The liquid dispenser 3 comprises at least one nozzle for jetting a stream of liquid onto the floor surface FS. The at least one nozzle 35 has a central axis which is inclined positioned in a forward direction with respect to the driving direction D under an angle of inclination with respect to the axis of rotation A-A.

[0074] Although the present invention has been described in detail, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as hereinafter claimed. It is intended that all such changes and modifications be encompassed within the scope of the present disclosure and claims.

TABLE-US-00001 List of reference signs: IS inner space FS floor surface LM liquid medium AA axis of rotation NN central axis of nozzle D driving direction angle of inclination V volume of liquid medium 1 surface cleaning device 2 casing 21 circumferential casing wall 22 casing top wall 23 casing outlet 3 liquid dispenser 30 rotor 31 rotor shaft 32 rotor arm 321 blade arm 322 nozzle arm 33 motor 34 blade 340 blade face 341 blade tip 35 nozzle 35.1; r1 first nozzle/radius 35.2; r2 second nozzle/radius 35.3; r3 third nozzle/radius 35.4; r4 fourth nozzle/radius 36 rotor distributor 37 belt 38 rotor drive wheel 39 bearing