Drainer, Wet Mopping Device, And Wet-And-Dry Cleaning Head

Abstract

A drainer having: a housing including a plurality of water discharge holes at the bottom, at least one water inlet at the top, and a cavity inside, the water inlet, cavity, and the water discharge holes in communication sequentially; and a plurality of absorbent cores partially exposed from a corresponding water discharge hole such that each of the absorbent cores is configured to guide water flowing into the cavity to the exterior of the housing through the water discharge holes. The drainer may be configured with a wet mopping device and wet and dry cleaning head.

Claims

1. A drainer for a floor cleaning equipment comprising: a housing with a plurality of water discharge holes at a bottom, at least one water inlet at a top, and defining a cavity inside, the water inlet, the cavity, and the plurality of water discharge holes in communication sequentially; and a plurality of absorbent cores mounted in the cavity of the housing, each of the plurality of absorbent cores partially exposed from a corresponding water discharge hole, such that each of the plurality of absorbent cores is configured to guide water entering the cavity to the exterior of the housing through the water discharge holes.

2. The drainer for a floor cleaning equipment according to claim 1, wherein the housing is integrally formed, and the absorbent cores are permanently limited inside the housing.

3. The drainer for a floor cleaning equipment according to claim 1, wherein the housing is formed by at least two parts separable from each other, so that the plurality of absorbent cores are replaceable.

4. The drainer for a floor cleaning equipment according to claim 1, further comprising a water guiding member capable of guiding water to flow from one side to another at an inner bottom face of the cavity; each of the plurality of absorbent cores in contact with the water guiding member, so that water flowing onto the water guiding member is guided to the plurality of absorbent cores.

5. The drainer for a floor cleaning equipment according to claim 4, wherein the water guiding member and the plurality of absorbent cores are integrally formed.

6. The drainer for a floor cleaning equipment according to claim 1, further comprising a partition located above the plurality of absorbent cores inside the cavity, the partition having a plurality of through holes via which water flowing into the cavity flows to the plurality of absorbent cores below.

7. The drainer for a floor cleaning equipment according to claim 6, wherein an upper surface of the partition is an oblique face that inclines downwards from near the water inlet to away from the water inlet.

8. The drainer for a floor cleaning equipment according to claim 4, further an inner wall face of the housing comprises at least one positioning pin on which the water guiding member is sleeved.

9. The drainer for a floor cleaning equipment according to claim 4, wherein an inner wall face of the housing comprises a plurality of plots located above the plurality of absorbent cores, each of the plurality of plots facing one water discharge hole, the plurality of absorbent cores tightly pressed inside the water discharge holes by the plurality of plots.

10. A wet mopping device, comprising: a base plate for mounting a mop cloth; and a water supply tank located above the base plate for supplying water to the mop cloth, a bottom of the water supply tank comprising a water outlet; wherein, the base plate comprises a drainer according to claim 1, the water inlet is in communication with the water outlet, and the housing of the drainer is at least partially separable from the base plate.

11. The wet mopping device according to claim 10, wherein the base plate comprises a venting pipe connecting the cavity of the drainer with the water supply tank, the venting pipe protruding from an upper surface of the base plate and up to above a maximum fill level of water in the water supply tank, the housing of the drainer comprising a connecting port connected with the venting pipe.

12. The wet mopping device according to claim 10, wherein, an upper half of the housing is integrally formed with the base plate, and a lower half of the housing is detachably connected to the upper half.

13. The wet mopping device according to claim 12, wherein, the base plate further comprises a protrusion protruding inside the cavity of the drainer.

14. The wet mopping device according to claim 10, wherein the housing of the drainer is integrally separable from the base plate.

15. The wet mopping device according to claim 14, wherein the base plate further comprises a groove for receiving the housing.

16. The wet mopping device according to claim 10, wherein, a top of the water supply tank comprises a water filling port, a tank cap is arranged at the water filling port and comprises an air inlet open towards an interior of the water supply tank and an air opening open towards the outside of the water supply tank, the tank cap further comprises a chicane shape formed by at least one baffle and forming an air inlet channel extending inside the tank cap from the air inlet to the air opening.

17. The wet mopping device according to claim 10, wherein the base plate and the water supply tank are integrally fixed or integrally formed.

18. A wet-and-dry cleaning head for a floor cleaning equipment, comprising: a cleaning head body with at least one dust suction port at the bottom; a base plate for mounting a mop cloth; a water supply tank located above the base plate for supplying water to the mop cloth, a bottom of the water supply tank comprising a water outlet; wherein the base plate comprises a drainer according to claim 1, the water inlet at the top of the housing is in communication with the water outlet, the housing of the drainer is at least partially separable from the base plate.

19. The wet-and-dry cleaning head according to claim 18 for a floor cleaning equipment, wherein the base plate is located at a bottom of the cleaning head body, and the water supply tank is detachably mounted at a top of the cleaning head body.

20. The wet-and-dry cleaning head according to claim 19 for a floor cleaning equipment, wherein the base plate is detachably mounted at the bottom of the cleaning head body.

21. The wet-and-dry cleaning head according to claim 18 for a floor cleaning equipment, wherein the base plate and the water supply tank are integrally fixed or integrally formed, and are detachably mounted to the cleaning head body.

22. The wet-and-dry cleaning head according to claim 18, wherein the base plate comprises at least one locking element which cooperates with a corresponding locker arranged on the cleaning head body so as to lock the base plate with the cleaning head body.

Description

DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a schematic perspective view of a wet-and-dry cleaning head of the present invention;

[0042] FIG. 2 is a schematic exploded view of a wet-and-dry cleaning head of the present invention;

[0043] FIG. 3 is a schematic top view of a wet mopping device of the present invention;

[0044] FIG. 4 is a first schematic cross-sectional structural view of a wet mopping device of the present invention (after a user operates an action member in one direction, a valve closes the water outlet on the base plate of the water supply tank);

[0045] FIG. 5 is second schematic cross-sectional structural view of a wet mopping device of the present invention (after a user operates the action member in another direction, the valve opens the water outlet on the base plate of the water supply tank);

[0046] FIG. 6 is a schematic exploded view of a drainer of the present invention;

[0047] FIG. 7 is a schematic partial enlarged view of the detail A in FIG. 5;

[0048] FIG. 8 is a schematic bottom view of an upper cover of a drainer of the present invention;

[0049] FIG. 9 is a schematic top view of the remaining part of a drainer of the present invention after the upper cover is removed;

[0050] FIG. 10 is a schematic cross-sectional structural view of a drainer of the present invention;

[0051] FIG. 11 is a schematic perspective view of another embodiment of the wet mopping device of the present invention;

[0052] FIG. 12 is a cross-sectional structural view of the wet mopping device as shown in FIG. 11;

[0053] FIG. 13 is a schematic exploded view of the water filing part of the wet mopping device as shown in FIG. 11;

[0054] FIG. 14 is a schematic side view of the wet mopping device as shown in FIG. 11.

[0055] wherein: 11. Cleaning head body; 111. Dust suction port; 112. Suction passage; 113. Rotary connector;

[0056] 12. Wet mopping device; 121. Base plate; 122. Water supply tank; 123. Groove; 124. Water outlet; 125. Air inlet; 126. Action member; 127. Valve; 128. Plug; 129. Spring; 130. Mounting hole; 131. Check valve; 132. Rotating shaft; 133. Sealing ring; 134. Water filling port; 135. Cover; 136. Cover part; 138. Lining part.

[0057] 14. Drainer; 141. Housing; 142. Upper cover; 143. Lower cover; 144; Water inlet; 145. Cavity; 146. Partition; 147. Through hole; 140. Absorbent member; 148. Absorbent core; 149. Water guiding member; 150. Water discharge hole; 151. Plot; 152. Positioning pin; 153. First positioning hole; 154. Second positioning hole; 155. Positioning slot; 156. Small hole.

[0058] 22. Locking element; 24. Venting pipe; 26. Internal wall; 32. Fixing hole; 33. Screw hole; 36. Chicane shape; 361. Inner skirt; 362. Ribs; 363. intermediate air opening; 364. first notch; 37. Outer skirt; 373. block; 374. second notch; 38. Air inlet; 41. Cam surface; 42. First edge; 43. Protrusion; 44. Second edge; 34. Upper sealing ring; 50. Lever arm.

DETAILED DESCRIPTION OF THE INVENTION

[0059] The technical contents, structural features, achieved objectives and effects of the present invention will be described in detail below with reference to embodiments and the accompanying drawings. The positional relationships of upper, lower, left, right, front, and rear described in the present embodiments correspond to the respective positional relationships shown in FIG. 1, respectively. The floor cleaning equipment described is an equipment used for performing dust suction and cleaning on a floor to be cleaned. It can be for example a wet-and-dry vacuum cleaner, or a floor scrubber.

[0060] As shown in FIG. 1 and FIG. 2, a wet-and-dry cleaning head comprises a cleaning head body 11 capable of moving on a floor to be cleaned, a rotary connector 113 connected to the cleaning head body 11, a suction passage 112, and a wet mopping device 12 fixedly mounted to the cleaning head body 11. In the wet-and-dry cleaning head, a part of the suction passage 112 is received inside the cleaning head body 11, and another part of it is provided on the rotary connector 113. The cleaning head body 11 is provided at the bottom with two dust suction ports 111 that are opposite each other in the front-rear direction. When the wet-and-dry cleaning head is applied to be used on a floor cleaning equipment, it is connected with a main body portion of the floor cleaning equipment via the rotary connector 113, for example, to a suction unit of the floor cleaning equipment by means of a hard tube or a hose. The suction passage 112 is capable of sucking in particulate matter such as dust on the floor to be cleaned through the dust suction ports 111 by means of a suction force of the suction unit. Of course, it is also possible to provide only one dust suction port 111 at a front portion of the cleaning head body 11, in front of the wet mopping device 12. Thus, a function of first dusting and then mopping can be realized.

[0061] As shown in FIG. 3 and FIG. 4, the wet mopping device 12 comprises a base plate 121 used for mounting a mop cloth and a water supply tank 122. A lower portion of the water supply tank 122 is of an opening structure. The base plate 121 is fixedly mounted at the lower portion of the water supply tank 122 and closes the opening of the lower portion of the water supply tank 122, so that the water supply tank 122 and the base plate 121 enclose and define a water storage chamber. Of course, to facilitate manufacturing by injection molding, the base plate 121 and the water supply tank 122 can also be integrally formed.

[0062] To facilitate the adding of cleaning water by a user, a wet mopping device 12 is detachably mounted to the cleaning head body 11. Specifically, the water supply tank 122 has two tank portions that are opposite each other in the left-right direction, and a connection portion that connects the two tank portions. The connection portion is of a hollow structure and integrally formed with the two tank portions. The space between the two tank portions forms a snap groove. The cleaning head body 11 has a snap-in portion adapted to the snap groove. When the wet mopping device 12 is mounted to the cleaning head body 11, the snap-in portion of the cleaning head body 11 is snapped in the snap groove of the wet mopping device 12, and the water supply tank 122 is located at the top of the cleaning head body 11. An upper portion of the water supply tank 122 is provided with a water filing port 134, and a cover 135 is provided at the water filing port 134.

[0063] Of course, to facilitate the mounting of a mop cloth, the wet mopping device 12 does not need to be completely detached from the cleaning head body 11. It is sufficient to fix the water supply tank 122 to the cleaning head body 11, and detachably provide the base plate 121 at the bottom of the water supply tank 122. Specifically, the base plate 121 is connected to the water supply tank 122 in a snap-fit manner, with a lower edge of a side wall plate of the water supply tank 122 constituting a connection portion and the base plate 121 being provided with a circumferentially arranged connection groove adapted to the lower edge of the side wall plate of the water supply tank 122, and a waterproof sealing strip being provided in the connection groove.

[0064] The base plate 121 is provided with a water outlet 124. A drainer 14 that communicates with the water outlet 124 is mounted to the base plate 121. When a mop cloth is mounted at the lower portion of the base plate 121, the mop cloth covers the outer side of the drainer 14. Cleaning water in the water storage chamber can be guided to the mop cloth via the drainer 14, so as to humidify the mop cloth.

[0065] To facilitate the cleaning water in the water storage chamber entering the drainer 14 so as to be guided to the mop cloth, the water supply tank 122 is provided with an air inlet 125 that puts the external environment and the internal water storage chamber in communication. The air inlet 125 is provided on the cover 135. A check valve 131 is mounted at the air inlet 125. The check valve 131 only allows outside air to enter the water supply tank 122 from the outside, and does not allow air and/or cleaning water in the water supply tank 122 to escape from the interior of the water supply tank 122 into the external environment. As a result, even if the water supply tank 122 is in an upside-down state, the cleaning water inside the water supply tank 122 cannot leak to the floor to be cleaned through the air inlet 125, effectively preventing the drawback of making the floor dirty again when a user replaces the cleaning water.

[0066] Of course, the water supply tank 122 can be of a fully closed structure, i.e., a structure without the air inlet 125. Cleaning water in the water storage chamber is guided to the mop cloth so as to humidify it only by means of the capillary effect of the drainer 14.

[0067] To prevent the water in the water supply tank 122 from being continuously guided to the mop cloth by the drainer 14 after finishing a mopping operation, which results in an excessive water content on the mop cloth and thus leaving a large area of water stain on the floor to be cleaned, a valve 127 for opening and closing the water outlet 124 is mounted at the water outlet 124, as shown in FIG. 4 and FIG. 5. An action member 126, operable by a user and drivingly connected with the valve 127, is provided at an upper portion of the water supply tank 122. In use, by operating the action member 126, the user drives the valve 127 to perform an action so as to open or close the water outlet 124 on the base plate 121.

[0068] Specifically, the water supply tank 122 is provided with a mounting hole 130. The valve 127 comprises a plug 128 and a spring 129 mounted inside the mounting hole 130. One end of the spring 129 is connected to the plug 128 and the other end of it is connected inside the mounting hole 130. The plug 128 is provided with a sealing ring 133 at a lower end. The action member 126 is a button member, one end of which is mounted to the water supply tank 122 by means of a rotating shaft 132, and the other end constitutes a trigger portion for a user to press or step on. An upper end of the plug 128 abuts against the button member. Of course, the action member 126 is not limited to the above-described button-type rotating member. It can also be a movable member. The structure of the valve 127 is not limited to the above-described plug that moves in the vertical direction either. It can also be a cover plate that moves in the horizontal direction. For example, the movable member is fixedly connected to the cover plate. In use, by operating the movable member, the user drives the cover plate to move in the horizontal direction, so that the cover plate and the water outlet 124 are offset from each other or face each other, so as to open or close the water outlet 124.

[0069] The structural composition and application of the drainer 14 will be described specifically in reference to FIG. 2 and FIG. 4 to FIG. 10.

[0070] As shown in FIG. 2, the drainer 14 is mounted to the lower portion of the base plate 121. With reference to FIG. 4 and FIG. 5, the lower portion of the base plate 121 is provided with a groove 123. The drainer 14 is received in the groove 123. A bottom edge of the drainer 14 is substantially flush with a bottom surface of the base plate 121. As a result, when a mop cloth is mounted to the base plate 121, the mop cloth will not appear to be rugged, facilitating tight engagement between the mop cloth and the floor to be cleaned, and improving the mopping result.

[0071] As shown in FIG. 6, the drainer 14 comprises a housing 141, a partition 146, and an absorbent member 140 comprising absorbent cores 148. The housing 141 is formed by an upper cover 142 and a lower cover 143 fastened with each other. With reference to FIG. 10, a cavity 145 is enclosed between the upper cover 142 and the lower cover 143. The partition 146 and the absorbent cores 148 are all located in the cavity 145. The partition 146 is located above the absorbent cores 148. The absorbent cores 148 are made of a material with good absorbent property, for example, water-absorbent resin, cellulose, polyacrylamide, or degreased cotton, sponge, silicone, etc.

[0072] In order to tightly fix the partition 146 and the absorbent cores 148 in the cavity 145 by the upper cover 142 and the lower cover 143 after being fastened with each other, with reference to FIG. 8, the upper cover 142 is provided, along the direction of its length, with a plurality of positioning slots 155 and a plurality of plots 151 extending downwards. The plurality of plots 151 and the plurality of positioning slots 155 are provided one adjacent to another. That is to say, one plot 151 is provided between every two positioning slots 155. The lower cover 143 is provided, along the direction of its length, with water discharge holes 150 for inserting the plurality of plots 151 and a plurality of positioning pins 152 adapted to the plurality of positioning slots 155. The plurality of water discharge holes 150 and the plurality of positioning pins 152 are provided one adjacent with another. That is to say, one water discharge hole 150 is provided between every two positioning pins 152. The partition 146 is provided, along the direction of its length, with first positioning holes 153 for being traversed by the plurality of positioning pins 152 and a plurality of through holes 147 for being traversed by the plurality of plots 151. The plurality of first positioning holes 153 and the plurality of through holes 147 are provided one adjacent with another. That is to say, one through hole 147 is provided between every two first positioning holes 153. The partition 146 is further provided with a plurality of small through holes 156 for cleaning water to flow through the partition 146. Each small hole 156 is integrally formed with the corresponding first positioning hole 153. The absorbent member 140 is provided, along the direction of its length, with second positioning holes 154 for being traversed by the plurality of positioning pins 152.

[0073] With reference to FIG. 6, FIG. 7, and FIG. 9, when the absorbent cores 148 and the partition 146 are fitted in the housing 141, the positioning pins 152 on the lower cover 143 traverse, sequentially, the second positioning holes 155 on the absorbent member 140 and the first positioning holes 153 on the partition 146, and finally are inserted inside the positioning slots 155 on the upper cover 142. At the same time, the plurality of plots 151 on the upper cover 142 traverse the plurality of through holes 147 on the partition 146 and are inserted inside the plurality of water discharge holes 150 on the lower cover 143, in the course of which, the absorbent cores 148 are tightly pressed inside the water discharge holes 150 by the positioning plots 151 on the upper cover 142, and are partially exposed outside the water discharge holes 150.

[0074] The upper cover 142 is provided with a water inlet 144 that communicates with the cavity 145. With reference to FIG. 4 and FIG. 5, when the drainer 14 is mounted at the lower portion of the base plate 121, the water inlet 144 and the water outlet 124 on the base plate 121 are in communication, and the water inlet 144 of the drainer 14, the cavity 145, and the water discharge holes 150 communicate with each other sequentially. The absorbent core 148 is able to guide cleaning water flowing into the cavity 145 to the outside of the housing 141 via the water discharge holes 150, i.e., to the mop cloth below it, so as to humidify the mop cloth.

[0075] In the above-described structure, the housing 141 of the drainer 14 is a separable structure with the upper cover 142 and the lower cover 143 being detachably connected. Of course, to facilitate manufacturing, the housing 142 of the drainer 141 can also be designed to be an integral structure with a cavity 145 enclosed inside, and the absorbent core 148 being permanently limited in the housing 141. However, as such, when any component inside the drainer 14 is damaged (for example, when problems such as clogging, cracks, and aging occur to the absorbent cores 148), a user needs to replace the entire drainer 14. To enable the user to selectively replace a component in the drainer 14 according to the actual situation of utilization, and mainly for facilitating the replacement of the absorbent core 148 by the user, the housing 141 is best designed to be a separable structure, which is not limited to a two-part structure with an upper cover and a lower cover, and can also be formed by multiple parts, for example, a drainer housing formed by an upper shell, a middle frame, and a lower shell, with the absorbent cores 148 fixed to the middle frame.

[0076] With reference to FIG. 2, the drainer 14 can be detachably mounted at the lower portion of the base plate 121. That is to say, the outer contour of the drainer 14 is adapted to the groove 123 on the base plate 121 in a snap-fit connection manner. The upper cover 142 of the drainer 14 can also be fixed to the base plate 121, with the rest of the drainer 14 such as the lower cover being designed to be removable.

[0077] As cleaning water entering the drainer 14 will generally fill up the cavity 145 before flowing to the absorbent cores 148 through the small holes 156 on the partition 146, in order to facilitate the absorption of the cleaning water inside the cavity 145 by the absorbent core 148, a water guiding member 149 is deposited at the inner bottom face of the cavity 145. The water guiding member 149 is in contact with the absorbent core 148. The water guiding member 149 also possess a good absorbent property, and is integrally formed with the absorbent core 148 and capable of guiding cleaning water to the absorbent cores 148.

[0078] In the above-described structure, the absorbent member 140 is of a one-piece structure, and the water guiding member 149 is integrally formed with the absorbent cores 148. Of course, to facilitate the mounting and replacement of a part of the absorbent core 148, the absorbent core 148 can also be a separable structure. That is to say, a plurality of absorbent cores 148 can be provided. The water guiding member 149 connects the plurality of absorbent cores 148 together. The water guiding member 149 is sleeved to the plurality of positioning pins 152 on the inner wall face of the housing 141. Each absorbent core 148 is in contact with the water guiding member 149, so that cleaning water flowing onto the water guiding member 149 can be guided onto the absorbent cores 148.

[0079] As the upper cover 142 is provided with only one water inlet 144, cleaning water entering the drainer 14 via the water inlet 144 will flow from near the water inlet 144 towards away from the water inlet 144. Thus, the water flow arriving at the absorbent cores 148 is not uniform, and the cleaning water ultimately flowing out of the various water discharge holes 150 is not uniform in time, resulting in the mop cloth being partially humidified and partially not humidified. To prevent this situation, it is preferable that an upper surface of the partition is designed as an oblique face, that is to say, inclined downwards from near the water inlet 144 to away from the water inlet 144, so that cleaning water in the drainer 14 flows more slowly when near the water inlet 144 and more quickly when away from the water inlet 144. The overall effect achieved is that the water output rates of the various water discharge holes 150 of the drainer 14 are substantially identical, and the mop cloth is humidified more uniformly with a better humidification result. Of course, other than designing the upper surface of the partition 146 as an oblique face, it is also possible to provide a plurality of water inlets 144 on the upper cover 142 along the direction of its length, which can also make the water output rates of the various water discharge holes 150 of the drainer 14 identical.

[0080] FIG. 11 to FIG. 14 illustrate another embodiment of the wet mopping device 12 which includes several other aspects of the invention. It should be understood that these aspects may also be applied to the above described embodiment or combined with above described features to constitute new embodiments. In FIGS. 11-14, same reference numbers are used to designate the identical or similar parts to the embodiment shown in FIGS. 1-10.

[0081] As shown in FIG. 11, the wet mopping device 12 comprises a base plate 121 and a water supply tank 122, which are similar to those shown in FIG. 2. Two locking elements 22 are provided on each of the front and rear borders of the base plate 121. In the illustrated embodiment, each locking element 22 is in the form of a hook having a recess 221 facing the center of the base plate 121. The cleaning head body 11 is provided with corresponding lockers respectively located on the rear surface of the front suction part and the front surface of the rear suction part (not shown in the figures). When the wet mopping device 12 is mounted to the cleaning head body 11, the locker arranged on the cleaning head body 11 are snapped in the recess of the locking element 22 provided on the base plate 121. This cooperation helps to ensure the fastening of the wet mopping device 12 to the cleaning head body 11, in addition or in alternative to the snap fit created by the snap groove formed by the water tanks and the snap-in portion of the cleaning head body 11. Moreover, the locking elements 22 also avoids that the mop cloth overlays completely the base plate 121.

[0082] As shown in FIG. 12, the base plate 121 is provided a venting pipe 24 protruding from the upper surface of the base plate 121 to above the maximum filing lever of the water supply tank 122. The housing 141 of the drainer 14 is provided with a connecting port (not shown) connected with the venting pipe 24. Thus, the venting pipe 24 connects the cavity 145 formed inside the base plate drainer 14 with the water supply tank 122. As shown in FIGS. 4 and 5, the base plate 121 only has one water outlet 124 through which water exits the water supply tank 122 and enters the cavity 145 of the drainer 14. It could be difficult for the air trapped in the cavity 145 to get out from the water outlet 124 and the filling of the cavity 145 can thus be obstructed. The venting pipe 24 allows to vent the air existing in the cavity 145 when filling the cavity 145 and thus facilitates the filling.

[0083] Also as shown in FIG. 12, the base plate 121 is provided with at least one internal wall 26, in the form of a longitudinal projection protruding from the upper surface to the inside of the cavity 145. The internal wall 26 occupies a part of the volume of the cavity 145 and thus reduces the volume of the cavity 145 that is occupied by water. Therefore, when the valve 127 is actuated to its open position, water can fill the cavity 145 more quickly and moisten the mop more quickly as well. In other words, the time response is decreased between the time the valve 127 is manually actuated and the time when the mop is moistened by water flowing from the liquid discharge holes 150. The quantity and the location of the internal walls 26 can be modified according to actual need. In addition, the internal walls 26 also serve as reinforcing elements of the base plate 121.

[0084] It can be seen from FIG. 12 that the drain valve 127 is provided with a lower sealing 133 realized by an O-ring for radial sealing and an upper sealing 34 realized by a washer with axial lip for axial sealing, in order to reduce the effort needed to operate the plug 128 of the valve 127. In the embodiment illustrated on FIG. 12, the valve 127 is entirely housed in the mounting hole 130. The lower sealing 133 and the upper sealing 34 both locate between the mounting hole 130 and the plug 128 of the valve 127.

[0085] Different from the previous embodiments shown in FIGS. 1 to 10, in the embodiment as shown in FIGS. 11 to 14, the tank cap 135 does not comprise an air inlet orifice that is visible from outside or a check valve but defines an air inlet channel extending between an air inlet 38 open towards the interior of the water supply tank 122 and an air opening 364 open towards the outside of the water supply tank 122. The air inlet channel is formed by a chicane shape 36 formed in the tank cap 135. The tank cap 135 comprises a cover part 136 and a lining part 138 that is mounted to the cover part 136. The chicane shape is formed on the top surface of the cover part 136 and protruding downwardly therefrom. In the illustrated embodiment, the chicane shape 36 comprises an inner skirt 361 forming a substantially rectangular contour and ribs 362 linking a screw hole 33 with the inner skirt 361. The lining part 138 is mounted to the bottom of the cover part 136 and comprises a plate provided with an orifice as an air inlet 38 and an outer skirt 37 protruding upwards from the plate and surrounding the air inlet 38. The lining part 138 is for instance mounted to the cover part 136 by means of a bolt (not shown) passing through a fixing hole 32 arranged in the plate of the lining part 138 and screwed in the screw hole 33 of the cover part 136. In the illustrated embodiment, the fixing hole 32 is located in the center of the plate.

[0086] When the cover part 136 and the lining part 138 are mounted by the bolt, the outer skirt 37 is sleeved outside the inner skirt 361, with its side S facing the side S′ of the inner skirt 361 as shown in FIG. 13. In addition, the height of the inner skirt 361 and the ribs 362 are dimensioned to allow them getting in contact with the plate of the lining part 138 when mounted, so that water could hardly pass through their interface with the plate of the lining part 138. As shown in FIG. 13, in this embodiment, four ribs 362 are disposed in the form of a cross with the screw hole 33 in the center. The ribs 362 form the baffles for water and/or air. It should be understood that the quantity and the distribution of the ribs may vary. When the cover part 136 and the lining part 138 are mounted, the air inlet 38 is located between two ribs 362, one of which is partially hollowed to leave an intermediate air opening 363 in the air inlet channel. Another rib adjacent to the hollowed rib is also hollowed to leave an intermediate air opening. The inner skirt 361 comprises a first notch 364 and the outer skirt 37 comprises a second notch 374 at the same location, so as to form an air opening. The first notch 364 extends on the whole height of the inner skirt 361 whilst the second notch 374 extends on a part of the height of the outer skirt 37. Preferably, as shown in FIG. 13, the outer skirt 37 comprises a block 373 protruding inwardly and is inserted in the first notch 364 of the inner skirt 361 when mounted. The first notch 364 is located between the other two ribs 362. In other words, the air inlet 38 and the air opening are located in diagonal quadrants defined by the four ribs. Thus, air entering the tank cap 135 passes firstly the air opening formed by the notches 364 and 374, then passes the intermediate air openings 363 formed in two adjacent ribs 362, and finally passes through the air inlet 38 to access the water supply tank 122. Conversely, when the water tank is tilted and the water tends to leak out through the tank cap 135, it is trapped between the cover part 136 and the lining part 138 by the baffles formed by the ribs 362 and the block 373. In another preferred embodiment, the intermediate air openings 363 may be located directly adjacent to the top surface of the cover part 136, so that they may trap the water more efficiently.

[0087] In order to lock the drain valve 127 in its closed or open position, a cam shape is formed at a top portion of the plug 128 of the drain valve 127. The top portion comprises a stepped surface including a higher surface 45 and a lower surface 46 which are connected by a cam surface 41. As shown on FIG. 14 wherein the drain valve 127 is in the open position, a lever arm 50 of the action member 126 rests on the lower surface 46 of the top of the plug 128. To switch the valve 127 to its closed position, the action member 126 should be rotated around its axis in the clockwise direction. The lever arm 50 of the action member 126 is thus pressed against the cam surface 41 by its first edge 42. When the cam surface 41 and the first edge 42 are being forced through, the lever arm 50 is moved downwards against a spring force that tends to urge the drain valve plug 128 upwards and comes to rest on the higher surface 45 of the top of the plug 128 which is thus pushed down to block the water outlet 125. Preferably, a protrusion 43 is provided on the higher surface 45 of the top portion of the plug 128, near the cam surface 41. Conversely, to open drain valve 127, the action member 126 should be rotated in the anticlockwise direction. The lever arm 50 is pressed against the protrusion 43 by its second edge 44. Only when the protrusion 43 and the second edge 44 are forced through, can the plug 128 be pushed upwards by the spring 132 and thus opens the valve 127.

[0088] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand and thereby implement the contents of the present invention, and the scope of protection of the present invention cannot be limited thereto. Any equivalent modifications or embellishments made in accordance with the spirit of the present invention shall be included within the scope of protection of the present invention.