Abstract
A washing machine (1) comprises a tub (2) and a draining circuit (16). The draining circuit (16) is fluidly connected to a lower portion of the tub (2). A valve (26) is arranged between the tub (2) and the draining circuit (16) and a recirculation circuit (10) is fluidly connected to the tub (2) for re-circulating fluid from a lower portion of the tub into the tub. An inlet (14) of the recirculation circuit (10) is positioned downstream of the valve (26).
Claims
1. A washing machine comprising: a tub; a draining circuit, wherein the draining circuit is fluidly connected to a lower portion of the tub; a valve arranged between the tub and the draining circuit, said valve comprising a valve body containing a movable closure element adapted to close or open the valve based on a water level due to buoyancy of the movable closure element, wherein the draining circuit is fluidly disconnected from the lower portion of the tub when the closure element closes the valve; a recirculation circuit fluidly connected to the tub for re-circulating fluid from the lower portion of the tub into the tub, wherein: an inlet of the recirculation circuit is positioned downstream of said valve and arranged at a bottom and/or a lower portion of the valve body; said washing machine comprises a filter element for preventing foreign objects from entering the recirculation circuit; wherein the inlet of the recirculation circuit is arranged behind the filter element and said filter element is attached at the inlet of the recirculation circuit; said filter element comprises at least one aperture formed between fingers or rake pins; said filter element extends or protrudes at least partially into an inner space of said valve body; and said filter element is arranged in such a way as to act as a support for said movable closure element, and is configured such that in case of a low water level and said closure element is no longer buoyant on the water, said closure element does not cover a bottom region of said valve body or covers only a portion thereof; and a pump arranged to generate a flow of water through said valve body, wherein when said pump is not in operation and with a water level in said valve body greater than said low water level, said movable closure element is configured to rise due to buoyancy to close said valve and fluidly disconnect the draining circuit from the lower portion of the tub.
2. The washing machine according to claim 1, wherein said valve is closed and opened in dependency on a water level and/or a pressure difference between the tub and a body of said valve.
3. The washing machine according to claim 1, wherein the movable closure element has a spherical shape.
4. The washing machine according to claim 1, wherein the valve body comprises a sump container, or a portion of a sump container and/or a portion of a draining duct.
5. The washing machine according to claim 2, wherein said pump comprises a recirculation pump in said recirculation circuit, and operation of said recirculation pump can generate said pressure difference causing said valve to open.
6. The washing machine according to claim 5, further comprising a draining pump separate from the recirculation pump, the draining pump in said draining circuit, and operation of said draining pump can generate said pressure difference causing said valve to open.
7. The washing machine according to claim 1, wherein the valve comprises a valve seat, and wherein the movable closure element is configured to releasably engage with the valve seat when the movable closure element rises due to buoyancy to close the valve.
8. The washing machine according to claim 1, wherein the valve body comprises a sump container in the lower portion of the tub.
9. The washing machine according to claim 1, wherein the valve body comprises a lug having a passage forming said inlet, for connecting the recirculation circuit to the valve body.
10. The washing machine according to claim 1, wherein the valve body comprises an opening fluidly connecting an inner volume of the valve body and/or an inner volume of the tub to a pressure sensor.
11. The washing machine according to claim 1, wherein a main body of the filter element is cantilever mounted to extend into an interior of the valve body as a free-standing element.
12. The washing machine according to claim 1, wherein a gap is formed between the filter element and an inner surface of a body of said valve.
13. The washing machine according to claim 1, wherein the filter element is connected to or integrally formed with a lug serving to mount the filter element at an outlet of the valve body.
14. The washing machine according to claim 6, wherein the fingers or rake pins have a free-standing end aligned parallel to or partially extending into a flow direction of a water flow from the tub to the draining pump when the draining pump is operating.
15. The washing machine according to claim 1, wherein the filter element comprises at least two filter apertures.
16. The washing machine according to claim 15, wherein the apertures are arranged parallel to each other.
17. The washing machine according to claim 1, wherein the filter element comprises at least five filter apertures.
18. The washing machine according to claim 1, wherein the filter element comprises at least eight filter apertures.
19. The washing machine according to claim 15 wherein the apertures are shaped like a fork or a rake.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Reference is made in detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying figures.
(2) FIG. 1 is a schematic cross-sectional front view of a washing machine according to the invention.
(3) FIG. 2 is a schematic cross-sectional front view of the washing machine of FIG. 1 during filling of water into a tub thereof.
(4) FIG. 3 is a schematic cross-sectional view of the washing machine of FIG. 1, wherein the tub is partially filled with water.
(5) FIG. 4 is a schematic cross-sectional front view of the washing machine of FIG. 1 during a recirculation phase.
(6) FIG. 5 is a schematic cross-sectional front view of the washing machine of FIG. 1 during a draining phase.
(7) FIG. 6 is a perspective, partially cross-sectional side view of a part of an exemplary internal structure of a washing machine.
(8) FIG. 7 is a perspective, partially cross-sectional side view of the internal structure of the washing machine shown in FIG. 6.
(9) FIG. 8 is a partial cross-sectional view of a detail of the structure of the washing machine shown in FIG. 6.
(10) FIGS. 9a-d are perspective views and cross-sectional views of a valve as shown in FIG. 6.
(11) FIG. 10 is a cross-sectional side view of the valve of FIGS. 9a-d in a closed state.
(12) FIG. 11 is a cross-sectional side view of the valve of FIG. 9a-d in an opened state.
(13) FIGS. 12a-d are perspective views of a filter element as shown in FIGS. 9a-d.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
(14) FIG. 1 depicts a schematic cross-sectional front view of a washing machine 1 comprising a tub 2 with a drum 4 rotatably arranged therein. A draining circuit 16 preferably comprises a draining pump 18, a draining suction pipe 17, a draining riser pipe 19 and a draining filter 20. The draining suction pipe 17 is fluidly connected to the tub 2 to drain water, washing water or fluid from the tub 2 during a draining phase when the draining pump 18 is operated. A valve 26, preferably, but not necessarily, comprising a valve body 27 and a valve seat 22, advantageously in form of a diaphragm with an opening, is arranged between the tub 2 and the draining circuit 16. Advantageously, a movable closure element 24, for example a ball, which is freely movable or floatable in the valve body 27, is adapted to engage with the valve seat 22 to shut the tub 2 from the draining circuit 16. The movable closure element 24 is advantageously made of floatable material e.g. plastic, so that it can float on the water depending on the water level in the draining suction pipe 17/valve body 27. When the water level rises, the movable closure element 24 is raised towards the valve seat 22 until the movable closure element (e.g. the ball) closes the opening at the valve seat 22. The valve seat may be formed in a diaphragm or plate as shown in FIG. 1. In the depicted embodiment, the draining suction pipe 17 is pipe-shaped and forms (at least part of) the sump, and the valve body 27 is connected to the lowest point of the tub 2. However in other embodiments the draining suction pipe 17 may have different shapes, at least in the region directly below the opening to the tub.
(15) In a heating phase of a washing cycle, the water in the tub 2 is heated by a heating element (not shown) arranged in the tub. When the valve 26 is closed, only the water in the tub 2 is heated, not the water in the draining circuit 16, whereby the energy consumption of the washing machine is reduced.
(16) A recirculation circuit 10 is provided to circulate water or washing water from a lower portion of the tub 2 to an upper portion of the tub 2 (as in the embodiment shown), or to a middle portion of the tub. The recirculation circuit 10 preferably comprises a suction pipe 13 fluidly connected to the draining suction pipe 17 (forming the sump), a recirculation pump 12 and a recirculation pipe 11. When the recirculation pump 12 is operated, the laundry 44 in the tub 2 is efficiently wetted without having to provide an amount of water in the tub 2 which completely (or even partially) covers the laundry 44. I.e., on the one hand the water consumption during a washing cycle is reduced and on the other hand, due to reduced water consumption less water has to be heated, whereby the energy consumption is reduced.
(17) The recirculation pump 12 and the draining pump 18 are not watertight. Thus, the water level in the recirculation pipe 11 and the draining riser pipe 19 corresponds to the water level in the tub 2 or draining suction pipe 17 when the pumps 12 and 18 are not operated and the valve 26 is open.
(18) A filter element 28 is arranged downstream of the valve seat 22 in front of an inlet 14 of suction pipe 13 of the recirculation circuit 10. When the recirculation pump 12 is operated, the water passes the filter element 28 before it enters the recirculation circuit 10. The filter element 28 prevents fluff and foreign objects which may pass through the opened or partially opened valve 26 from entering the recirculation circuit 10, where they might obstruct a nozzle at the outlet of the recirculation pipe 11 or the recirculation pump 12. When no water is in the draining circuit 16, the recirculation pump 12 is operated or the water level is low, the movable closure element 24 rests on the bottom of the valve body 27 and/or on the filter element 28.
(19) FIG. 2 depicts a schematic cross-sectional front view of the washing machine of FIG. 1 at the beginning of a washing cycle. As depicted by arrows, tap water flows into the tub 2 via a water inlet 6. The tap water flows through a detergent drawer 8, from where it carries detergent into the tub 2 and drum 4 as indicated with the arrows. In this state the water level 42a is in a range where the movable closure element 24 is not abutting the valve seat 22 such that the valve 26 is open. Thus the water fills the draining circuit 16 and partially the recirculation circuit 10.
(20) FIG. 3 depicts a schematic cross-sectional view of the washing machine of FIG. 1 during a phase of the washing cycle when the tub 2 is filled with water up to the maximum water level 42b for the selected washing program. In this phase the draining pump 16 and the recirculation pump 12 are not activated. The washing water has reached maximum level 42b which partially covers the laundry 44 in the tub 2. While the water level was rising from level 42a to 42b and due to the hydrostatic buoyant force, the movable closure element 24 is pushed or pressed against the valve seat 22 and closes the valve 26 thereby. The valve 26 provides a simple and robust way for automatically shutting off the tub 2 from the draining circuit 16 during those phases of the washing cycle, in which the pumps 12, 18 are not operated and in which the water level has a minimum height to press the movable closure element 24 against the valve seat 22. In particular the valve 26 is preferably closed during a heating phase when the water is filled to close the valve and when no pumps are operated.
(21) FIG. 4 depicts a schematic cross-sectional front view of the washing machine 1 of FIG. 1 during a recirculation phase of a washing cycle. The recirculation pump 12 is activated and pumps the washing water from the sump or the draining suction pipe 17 to the outlet of the recirculation pipe 11 (which may have a nozzle) which is connected to the interior of the tub 2. While operating the recirculation circuit 10, recirculation pipe 11 is filled with water and the water level drops from maximum level 42b to an intermediate washing level 42c. As shown in the embodiment of FIG. 4, the recirculation circuit feeds the water into the tub 2 and onto the drum 4. The drum 4 comprises holes or perforations through which the washing water enters the drum 4 and wets the laundry 44. Alternatively, the recirculation circuit 10 feeds the water directly into the drum 4 through an outlet at a rotational axis of the drum 4 (FIG. 6). In another embodiment (not shown), the outlet of pipe 11 or a nozzle is arranged at a loading door of front-loader washing machine such that the recirculated water can be sprayed or sprinkled through the loading opening of the drum directly into the drum and the laundry 44 therein.
(22) It may happen that detergent, in particular powder detergent, is not completely dissolved at the beginning of a washing cycle. For example, at the beginning of flushing in the detergent by flowing tap water through the detergent drawer 8 and before the water level is high enough to close the valve 26 (see e.g. water level 42a), some detergent may remain undissolved and can be flushed along the tub inner wall through the opening in the seat 22 into the sump or draining suction pipe 17. There it may collect due to gravity. Additionally, even if the water level is high enough to close the valve 26, undissolved detergent collecting at the lowest point of the tub 2 may enter the draining circuit if valve 26 does not perfectly close the opening in the seat 22, e.g., during drum rotation operation of the washing machine.
(23) As indicated by FIG. 4, the activated recirculation pump 12 creates a suction force on its suction side which opens or partially opens the valve 26 due to the pressure difference acting on the movable closure element from above and below, and the movable closure element's buoyant force. The movable closure element 24 is moved away from its seat 22. Thereby water can be pumped from the tub 2 although the inlet 14 of the recirculation circuit 10 is placed downstream the valve seat 22. I.e., the valve 26 is automatically opened during a recirculation phase of a washing cycle by the suction force of the recirculation pump 12. Referring to the collection of detergent in the sump or the draining suction pipe 17 described before, as the inlet 14 of the recirculation circuit 10 is placed below or downstream of the valve seat 22, any detergent deposited or collected in the sump or pipe 17 is recirculated back into the tub 2 when operating the recirculation circuit, whereby the detergent is effectively and efficiently used for the washing cycle.
(24) FIG. 5 depicts a schematic cross sectional front view of the washing machine 1 of FIG. 1 during a draining phase of a washing cycle. The flow of the washing water is depicted with arrows. The suction force of the draining pump 18 on its suction side opens the valve 26 and the draining pump 18 pumps water from the tub 2 and also from the recirculation circuit 10 through the draining riser pipe 19 and out of the washing machine 1. The washing water exiting the tub 2 and flowing past the filter element 28 cleans the filter element 28, i.e. washes or flushes the filter element 28. Preferably the filter element 28 is arranged in the draining flow, draining circuit 16 or valve body, such that the water flowing from the tub 2 in a draining phase hits the filter element 28 at an acute angle with respect to the surface 30 of the filer element 28. Thereby fluff and foreign objects caught by the filter element 28 are washed away from the filter element 28 during the draining of water. In other words, the filter element 28 forms a deflector element which deflects or redirects the draining flow from the tub 2 to the draining circuit 16, in particular to the draining suction pipe 17. Further, in the flow or current of the washing water out of the tub 2, the movable closure element 24, in particular if it is ball shaped, moves mainly in a rotational movement (arrow). This movement of the movable closure element 24 creates a vortex which assists in removing fluff and foreign objects from the filter element 28. In other words a self-cleaning filter element 28 is provided. Additionally, the backflow of water from the recirculation circuit 10 and out of the recirculation pipe 11 (as indicated by the falling water level 42d) assists in washing any caught foreign objects away from the filter element 28. Foreign objects which are washed from the filter element 28 or out of the tub 2 are subsequently caught in the draining filter 20, which is accessible from the outside for a user for cleaning. This is particularly advantageous if the filter element 28 itself is not accessible for a user from outside the washing machine.
(25) FIG. 6 depicts a perspective, partially cross-sectional side view of a part of an exemplary internal structure of a washing machine 1 as schematically depicted in FIG. 1, which in this embodiment is a top-loading washing machine. The same reference signs are used for the same features of the washing machine 1 as described above. Relating to technical details and functional operation, full reference is made to the above embodiment schematically shown. The drum 4 is rotationally supported in the tub 2. Below the tub 2 the valve 26 is shown in a partial cross-sectional view. The movable closure element 24 (in this case ball-shaped) is engaged in the valve seat 22 and shuts the tub 2 from the draining circuit 16 in the state as depicted. The inlet 14 of the recirculation circuit 10 is located below the valve 26, in particular below the valve seat 22. The suction side of the recirculation pump 12 is connected via suction pipe 13 to the sump or draining suction pipe 17. The output side of the pump 12 is advantageously connected via recirculation pipe 11 to a passage through and having an outlet preferably at a rotational axis of the drum 4. The draining circuit 16 is fluidly connected to the tub 2 through the opening in the valve seat 22 (having the form of a diaphragm or plate) such that washing water can be drained from the tub 2 through pipe 17, draining filter 20, pump 18 and draining riser pipe 19 to the outside of the machine with the draining pump 18 operating.
(26) FIG. 7 shows a perspective, partially cross-sectional side view of the structure of FIG. 6. In this partial cross-sectional view, the filter element 28 can be seen, which is arranged at the inlet 14 of the recirculation circuit 10. FIG. 8 shows a partial cross-sectional view of a detail of the structure of FIG. 6. The diaphragm or plate of the valve seat 22 is attached at the lower rim of an extension of the tub 2, extending at the bottom of the tub. The valve body 27 receiving the movable closure element 24 is preferably attached to the tub extension at the diaphragm and is forming part of the draining section pipe. Advantageously, both the suction pipe 13 and the draining suction pipe 17 have sections formed as a bellows. The bellows serve for damping vibrations of the tub from being transferred to the pumps 12, 18.
(27) FIGS. 9a-d depict perspective, cross sectional views of the valve 26 as shown in FIG. 6. FIG. 9a shows a top view of the valve 26, wherein the diaphragm forming the valve seat 22 is shown from the tub side. A lug 29 is attached to and protruding from the valve body 27 which is used to attach one end of the suction pipe 13. The filter element 28 is attached to the lug 29; preferably the filter element 28 is made as a single or monolithic part with the lug. The lug 29 is used to mount the filter element 28 at an outlet in the valve body 27, wherein the outlet forms the inlet 14 to the suction circuit 10.
(28) Preferably, a further opening 37 in the valve body 27 fluidly connects the interior of the valve body 27 to a duct 36 depicted in FIG. 9a-d. The duct is preferably connected to a pressure control (pressostat, not shown) for detecting the water level 42 in the tub 2.
(29) FIG. 9b shows a cross sectional view of the valve 26 along line A-A of FIG. 9a. The valve 26 is shut or closed by movable closure element 24 which rests in its seat 22 and blocks thereby the opening in the valve 26. The filter element 28 is attached to the inlet 14 of the recirculation circuit 10 by the mounting portion or lug 29 which is connected to the recirculation circuit by a plug connection. In particular the filter element 28 is attached to the lug 29 forming the inlet 14 in a cantilevered manner, such that the main body of the filter element 28 extends into inner volume of the valve body 27 in a free-standing manner. A portion of the filter element 28 facing the inner space of the valve body 27 preferably comprises a bent shape which corresponds or basically corresponds to the shape of the movable closure element 24.
(30) FIG. 9d shows a cross sectional view from below along the line B-B shown in FIG. 9c. In this embodiment the filter element 28 has advantageously a fork-like shape and comprises fingers 35a-d with apertures 34a-e between the fingers having open entrances 38a-e (or gaps) to the fingers. Advantageously, the fingers of the filter form the teeth or pins of a rake. The fingers 35a-d are preferably parallel or essentially parallel to a flow path of water flowing from the tub through the valve body 27 to the draining pump 18 in draining phases.
(31) FIG. 10 shows a cross-sectional side view of the valve of FIGS. 9a-d in a closed state, which has been described with respect to FIG. 3. Due to the water filling the tub 2, the draining circuit 16 and partially the recirculation circuit 10, the resulting buoyant force on the floatable movable closure element 24 presses the latter against the valve seat 22 (both pumps 12, 18 are not operating).
(32) FIG. 11 shows a cross-sectional side view of the valve of FIGS. 9a-d in an opened state, which has been described with respect to FIGS. 2, 4 and 5. Due to a low water level 42a (FIG. 2) or due to the suction force of the recirculation pump 12 (FIG. 4) or suction force of the draining pump 18 (FIG. 5) the valve 26 is opened. The movable closure element 24 is advantageously in close proximity to the filter element 28 or supported by the filter element, which comprises a curved shape which matches or substantially matches the shape of the movable closure element 24. A rotational movement of the movable closure element 24 due to the water flow during a draining phase assists the removal of e.g. fluff from the filter element 28 as described above.
(33) FIGS. 12a-d show perspective views of the filter element 28 as shown in FIG. 6. FIG. 12a shows the filter element 28 from above, i.e. the upper surface 30 of the filter element which faces the interior of valve body 27. The filter element 28 advantageously comprises a plurality of apertures 34a-e, which extend to a lateral border of the filter element 28 such that each aperture 34a-e has a laterally open side.
(34) FIG. 12b shows the filter element 28 from below, i.e. it shows the surface 32 of the filter element 28 which faces away from the movable closure element 24 or valve 26. As described above, the filter element is advantageously part of the lug 29 which forms at the same time a mounting portion for mounting the filter element 28 in the opening of the valve body 27. Thereby the filter element 28 is supported on one side in a cantilevered manner and the main body of the filter element 28 projects into the inner space of the valve body 27. The outer surface of the filter element 28 faces a portion of the inner surface of the valve body 27 and the filter element 28 is preferably arranged such that there is a gap 33 between the outer or lower surface 32 of the filter element and the inner surface of the valve body.
(35) FIG. 12c shows a side view of the filter element 28, wherein an arrow depicts the flow of water during a recirculation phase of a washing cycle. FIG. 12c also shows attachment of the recirculation pipe 11 on the lug 29. The water passes through the apertures 34a-e of the filter element from the upper side 30 to the lower side 32 of the filter element 28 and enters the recirculation circuit 10, in particular through an opening in the mounting portion 29.
(36) The arrows in FIGS. 12c and 12d indicate the water flow during a recirculation phase. Fluff or foreign bodies are retained at the fingers or teeth of the filter 28 and are washed along the fingers to a base of the fingers opposite to the aperture openings 34a-e where the fluff and foreign bodies collect. In contrast thereto, during a draining phase of a washing cycle the washing water flows past the filter element 28 from above coming through the aperture in the valve seat 22 and also some water flows in reverse direction out of the circulation circuit 10. This water flow washes the fluff and foreign bodies in direction from the base of the fingers towards the aperture entrances 38a-e. Thereby any fluff or objects caught in the filter element 28 are easily washed out and are not permanently caught in the filter element 28 (i.e. in the filter apertures 34a-e or the fingers of the filter). Further, preferably a portion of the filter element 28 in proximity to the recirculation circuit 10 has a closed surface. In other words the apertures 34a-e preferably do not extend across the entire surface of the part of the filter element 28 which extends into the draining circuit 16. The closed portion of the filter element 28 may catch larger foreign objects without the risk that these objects obstruct the apertures 34a-e of the filter element 28. Further, the closed portion of the filter element 28 assists the above described deflection of the drain water flow and assists thereby in efficiently cleaning the filter element 28.
(37) The present invention has been described in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
