AU2012200760A1

AU2012200760A1 - Laundry dryer with fluff filter cleaning

Info

Publication number: AU2012200760A1
Application number: AU2012200760A
Authority: AU
Inventors: Christoph Hansmann
Original assignee: V-Zug AG
Current assignee: V-Zug AG
Priority date: 2011-03-01
Filing date: 2012-02-08
Publication date: 2012-09-20
Also published as: CH704608A2; EP2495363A1; CN102653918A

Abstract

Abstract In order to clean the fluff filter (6) of a 5 laundry dryer a suction nozzle (11) is provided. The fluff filter (6) can be rotated relatively to the suction nozzle (11) such that the suction nozzle (11) covers the whole fluff filter (6). The air from the suction nozzle (11) is fed to a suction device (22), which separates the 10 fluff from the air and feeds the fluff to a fluff container (24) . In this manner the fluff filter (6) can be cleaned efficiently. 15 (Fig. 2) .... ....... . 5.. .. .... ....... 8- 2-82 -- ................... F ig . 1 6 '..~.-.----......... 1 63 - .17 -- 17 Fig. 2 Fig. 3

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title Laundry dryer with fluff filter cleaning The following statement is a full description of this invention, including the best method of performing it known to me/us: P/00/011 "Aflf 1 a Field of reinvention 5 The invention relates to a laundry dryer with a fluff filter and a cleaning device for cleaning the fluff filter. Background 10 A laundry dryer should be provided with at least one fluff filter for removing fluff from the processing air. Such a fluff filter is e.g. arranged in the door of the device. 15 In most of the conventional devices the fluff filter has to be cleaned by hand or has to be replaced periodically. EP 2 226 421 describes a laundry dryer where a cleaning device is provided for automatically cleaning the fluff filter. The cleaning device comprises 20 a wiper gliding over the fluff filter. Summary of the invention It is an object of the present invention to 25 design the cleaning device of the fluff filter in such a manner that a good cleaning action can be achieved. This object is met by the laundry dryer of claim 1. Accordingly the cleaning device comprises a suction nozzle for automatically cleaning the fluff 30 filter by aspirating the fluff from the fluff filter. By using such a suction nozzle, the cleaning effect is improved as compared to the effect that can be achieved by a wiper. Advantageously, the fluff filter is circular 35 and a rotating drive is provided in order to rotate the fluff filter in respect to, i.e. relatively to, the suction nozzle about the central axis of the fluff Dr. SU/sb/cw P106621AU00 01.02.2012 2 filter. Thus, a nozzle of small area can be used in simple manner for cleaning the whole filter. In a particularly advantageous embodiment the fluff filter is arranged at the door of the laundry 5 dryer. At this position it can, in particular, form a first filter that is passed by the processing air exiting from the drum, i.e. for the air carrying off the water from the humid laundry. In this case the circular design of the fluff filter with rotational drive, as described 10 above, is particularly advantageous because of its compact design. Advantageously a suction device connected to the suction nozzle is provided. This suction device is adapted to generate the underpressure in the suction 15 nozzle and it generates an auxiliary airflow for cleaning the fluff filter. It comprises a separator for depositing fluff from the air coming from the suction nozzle as well as a fluff container for receiving the deposited fluff. In this context, the term "depositing fluff" is to be 20 understood as separating fluff from the air. Short description of the figures 25 Further embodiments, advantages and application of the invention are given in the dependent claims as well as in the following description. This description makes reference to the annexed figures, which show: 30 Fig. 1 a laundry dryer with its housing shown in a partially transparent state, Fig. 2 a vertical sectional view of the door section of the laundry dryer, Fig. 3 a horizontal sectional view of the 35 door section of the laundry dryer, Fig. 4 the upper part of the drum of the laundry dryer with extended fluff container, Dr. SU/sb/cw P106621AU00 AlI A) If% II 3 Fig. 5 a first view of a suction device, Fig. 6 a second view of the suction device, Fig. 7 a horizontal sectional view of the suction device, 5 Fig. 8 a vertical sectional view of the suction device with the plunger in a first position, Fig. 9 a sectional view of Fig. 8 with the plunger in a second position, Fig. 10 the sectional view of Fig. 8 with the 10 plunger in a third position, Fig. 11 the sectional view of Fig. 8 with the plunger in a fourth position, Fig. 12 an embodiment with a fluff filter that can be rolled up, and 15 Fig. 13 an embodiment with two fluff filters. Embodiments of the invention 20 The embodiment of the laundry dryer shown in Figs. 1, 2, and 3 comprises a drum 1 for receiving the laundry to be dried as well as a door 2, through which the interior of drum 1 can be accessed. Further the device comprises means (not shown) for generating a 25 processing air flow L in drum 1. The processing air flow e.g. enters through the back wall of drum 1 and flows through drum 1 in substantially horizontal direction. Then it enters a cavity 3 in door 2 and leaves this cavity 3 through openings 4 in the frame 5 of the door. 30 From there the air enters at the dehumidification and heating device in the base of the laundry dryer and is then led back into drum 1 by means of a blower (not shown). As best can be seen from Figs. 2 and 3, a fluff filter 6 is arranged in door 2. Fluff filter 6 is a fine 35 net with openings in the range of 0.05 - 0.15 mm, in particular 0.13 mm, which serve to retain fluff carried in the processing air. The shape of the fluff filter can, Dr. SU/sb/cw P106621AUO0 01 02 2012 4 as shown in Fig. 1, be circular. It is held in a circular frame 7, which, in its turn, sits in a rotating bearing 8 of doorframe 5. Hence fluff filter 6 is rotatable about a central axis 9 extending perpendicular to fluff filter 6. 5 A rotating drive (not shown) is provided, by means of which the fluff filter can be rotated about the central axis 9. As mentioned above, a suction nozzle 11 is arranged at fluff filter 6 (only shown in Figs. 2 and 3), 10 in order to aspirate the fluff from the fluff filter. It comprises a hollow body 12, which comprises an elongate opening 14, which is shown in dotted lines in Fig. 1. It extends advantageously from central axis 9 to the periphery of fluff filter 6, such that it glides over the 15 whole fluff filter during the rotation of the fluff filter about central axis 9, even though the area of opening 14 is smaller than the area of fluff filter 6. It must be noted that, alternatively or in addition, fluff filter 6 can be at rest and suction nozzle 11 can be 20 rotating. Advantageously, suction nozzle 11 is mounted to door 2 and pivotal with the same, such that it provides access to drum 1 when opening door 2. In order to achieve a good cleaning even if 25 the flow of suction air is comparatively weak, the distance between opening 14 and fluff filter 6 should not be too large. Advantageously this distance is no more than 4 mm. Opening 14 does, however, not need to contact fluff filter 6 such that wear remains small. 30 Suction nozzle 11 is located at the entry side 16 of fluff filter 6, i.e. on side through which the processing air carrying fluff enters fluff filter 6 form drum 1, because this is the side where fluff accumulates. In addition to suction nozzle 11 a blowing 35 nozzle 18 can be arranged on an exit side 17 of fluff filter 6, i.e. on the side opposite to entry side 16, by means of which air can be blown against fluff filter 6. Dr. SU/sb/cw P106621AU00 11 A )1A1 5 Blowing nozzle 18 is located opposite to suction nozzle 11 such that a large percentage of the air exiting from blowing nozzle 18 enters suction nozzle 11. Opening 19 of blowing nozzle 18 has substantially the same shape and 5 size as the one of suction nozzle 11. Blowing nozzle 18 supports the cleaning operation. It has been found that, due to blowing nozzle 18, a lower air flow velocity is required during the cleaning operation and that noise is reduced. 10 Blowing nozzle 18 is connected through a connecting duct to a blower (not shown), by means of which substantially fluff-free fresh air can be fed to the blowing nozzle. Instead of fresh air, blowing nozzle 18 can also be fed with cleaned air that already has bee 15 used by the laundry machine - advantageously the air of the auxiliary airflow mentioned above can be cleaned such that it can be fed back to blowing nozzle 18. A suction duct 21 is connected to suction nozzle 11 and connects the same to a suction device 22, 20 whose design is now described in more detail with reference to Figs. 4 to 11. As can be seen from Fig. 4, suction device 22 is arranged laterally above drum 1. Its purpose is to generate the underpressure for aspirating air through 25 suction nozzle 11. In addition it comprises a separator for depositing fluff from the air flow coming from suction nozzle 11 and to feed the fluff to a fluff container 24. Fluff container 24 is advantageously designed 30 as a drawer and can be partially or completely removed through the front side of the laundry machine for emptying. Suction device 22 comprises a housing 25, and a plunger 26 arranged therein (see Figs. 6ff). Plunger 26 35 has several functions. For example it is used to wipe a separator filter 28 arranged in suction device 22. Further it is part of a compression device for Dr. SU/sb/cw P106621AU00 AI 1 A1l' 6 compressing the deposited fluff and for its transport to fluff container 24. Further it forms a closing device, by means of which at least one opening in the suction device can be closed and opened depending of the position of 5 plunger 26, which allows to control the flow of air. These functions are described in more detail in the following. A plunger drive 30 is provided for driving plunger 26. As can best be seen from Fig. 7, plunger 10 drive 30 drives a gear wheel 31, which engages a gear rod 32 of plunger 26, such that plunger 26 can be moved back and forth in a longitudinal direction. Plunger 26 comprises a head 33, which, during the movement of plunger 26, is moved from a first 15 position as shown in the Fig. 8 into a plunger chamber 34. Head 33 has substantially the same cross section as plunger chamber 34. Fluff container 24 is connected to plunger chamber 34 by means a filling opening 53. Filling opening 20 53 can be closed by a slideable or pivotal closing plate 54, which is driven by a closing drive 55. While cleaning fluff filter 6, fluff filter 6 is rotated and air is aspirated through suction nozzle 11. During this procedure plunger 26 is in its first 25 position as shown Fig. 8. Head 33 has not entered plunger chamber 34. Filling opening 53 is closed by closing plate 54. Air from suction nozzle 11 arrives through duct 21 in suction device 22, as shown with arrows in Fig. 8. The air enters through first openings 39 at the external wall 30 of plunger chamber 34 into the same and then passes separator filter 28, which is also arranged at the exterior wall of plunger chamber 34. If plunger chamber 34 is cylindrical, separator filter 28 can also have the shape of a cylinder or a cylinder segment. 35 From separator filter 28 the air enters a duct 40 and from there, through second openings 41, an auxiliary chamber 42. A base 44 of plunger 26 is arranged Dr. SU/sb/cw P106621AU00 ni nY Inn I 7 in auxiliary chamber 42 if plunger 26 is in the position of Fi.g 8. Base 44 has the shape of a hollow cylinder open at its rear end, whose outer diameter corresponds to the inner diameter of auxiliary chamber 42. In the 5 position of Fig. 8, a passage of the air through the first openings 41 into auxiliary chamber 42 is possible because plunger 26 is, in its first position, arranged such that third openings 45 in base 44 are aligned with the second openings 41. 10 The air in auxiliary chamber 42 leaves the same in axial direction and enters a blower chamber 47, in which a radial blower 48 is arranged. Radial blower 48 is driven by a blower drive 49. From blower chamber 47 the air exits radially into an exit duct 50, from where 15 it is discharged to the environment. Exit duct 50 can be closed by a baffle 51, which, however, is open in the position of Fig. 8. When the cleaning of fluff filter 6 is complete, radial blower 48 can be switched off. Now 20 plunger 26 is brought forwards into the second position shown in Fig. 9. Because separator filter 28 is flush with the outer wall of plunger chamber 34, head 33 glides along separator filter 40, thereby wiping off any fluff adhering to the filter and pushing it towards fluff 25 container 24, such that the fluff is compressed to a small volume between head 33 and closing plate 54. Therefore, head 33 together with closing plate 54 form a compression device for compressing deposited fluff, such that a larger amount of fluff can be stored in fluff 30 container 24. Now closing plate 54 moves away from filling opening 53 and opens the same. Then head 33 is advanced into fluff container 24, thereby pushing the compressed fluff into fluff container 24. 35 In a next step plunger 26 is brought into its third position as shown in Fig. 10, where head 33 is located in filling opening 53 flush to the interior wall Dr. SU/sb/cw P106621AU00 nAl In I1 8 of fluff container 24. Now closing plate 54 is closed, thereby wiping off any fluff attached to head 33. In a next step plunger 26 is brought into its fourth position as shown in Fig. 11. In this position 5 base 54 of plunger 26 closes the second openings 41 of auxiliary chamber 42, but releases third openings 56 of auxiliary chamber 42. These third openings 56 connect auxiliary chamber 42 to the environment. Head 33 of plunger 26 is now moved away from separator filter 28, 10 but still closes the first openings 39. Baffle 51 is pivoted downwards such that it closes exit duct 50. Closing plate 54 is again moved away from filling opening 53 and opens the same. Now radial blower 48 is operated again. It 15 sucks environment air through the third openings 56. From radial blower 48, this air now enters a passage 59, which has been opened by baffle 51, and from there the air enters duct 40. From duct 40, the air passes separator filter 28 and flows through plunger chamber 34 and 20 filling opening 53 into fluff container 24. The air flow in this process phase is illustrated by arrows in Fig. 11. When comparing the air flow of Fig. 11 with the one of Fig. 8, it is evident that, before wiping off the fluff (Fig. 8), the air is 25 fed in a first direction through separator filter 28 while, after wiping off the fluff (Fig. 11), the air is fed in a second direction through separator filter 28, with the second direction being opposite to the first direction. In this manner it is possible to remove even 30 the last fluff remains adhering to separator filter 28 and to maintain a good filtering function of the separator filter. As can be seen from the above, different closing means are arranged on plunger 26, which are 35 formed by head 33 and base 44, and which open and close several air openings as a function of the position of plunger 26. In more general terms, the closing means open Dr. SU/sb/cw P106621AU00 9 or close at least one air opening as a function of the position of the plunger 26. In the present embodiment the first, second and third openings 40, 41 and 56 are opened and closed, respectively. 5 When fluff container 24 is full, it is pushed forwards due to the pressure of the fluff such that it starts to open. A sensor (not shown) can be arranged at the fluff container for detecting such an opening motion, such that the user can be alerted that the machine does 10 not start because the fluff container is open and that the fluff container must be emptied. The operations of the device are controlled by a control unit, which is programmed to automatically operate the various drives at suitable times, e.g. as a 15 function of a program selected by the user. Advantageously, the fluff filter cleaning process is automatically started after each completed laundry drying process. The cleaning of fluff filter 6 by means of 20 suction nozzle 11 is advantageously only started towards the end of a drying process such that the aspirated fluff is substantially dry and therefore has a lower tendency to adhere to objects. Further, dry fluff is less likely to generate odours in fluff container 24. 25 Figs. 2 and 3 show only one possible embodiment of fluff filter 6. A further embodiment is shown in Fig. 12, where fluff filter 6 is a ribbon with a length much larger than its width. The end sections of the fluff filter ribbon are rolled up, e.g. at frame 5 of 30 the door, in the embodiment of Fig. 2 on two rolls 60. For cleaning this fluff filter 6, it is rolled off at one end and rolled up at the other by means of suitable drives connected to the rolls 60. Advantageously the same region of the fluff filter is repetitively used for a 35 large number of drying cycles (e.g. 200 drying cycles), until contamination remains large even after cleaning, such that further use does not make any sense. Then fluff Dr. SU/sb/cw P106621AU00 Al 1 ' ^- 10 filter 6 is advanced once about its height, such that a new section of filter 6 is brought into the air stream L. In this manner one filter module can be used for thousands of drying cycles, such that no replacement is 5 required during the whole operating life of the laundry dryer. A further variant of the fluff filter, which can be combined with the embodiments above, is shown in Fig. 13. In this embodiment two or more fluff filters 6, 10 6' are arranged behind each other in the air stream L. These filters can e.g. be arranged in the frame 5 of the door. A suction nozzle 11 is attributed to each of the filters for automatic cleaning. Advantageously a common rotating drive for both filters is arranged in frame 5, 15 in the manner shown in Figs. 2 and 3, in order to rotate the filters about axis 9. By using two filters, with the second filter (i.e. the filter passed as second filter by air stream L) having smaller openings, the cleaning effect can be 20 improved. The two filters can also be of different type, e.g. the first filter can be a net while the second filter is formed by an open-pored sponge. In summary, a device for cleaning the fluff filter of a laundry dryer is proposed. The fluff filter 25 can be rotated relatively to the suction nozzle such that the suction nozzle covers the whole fluff filter. The air from the suction nozzle is fed to a suction device, which deposits the fluff and feeds it to a fluff container. In this manner the fluff filter can be cleaned efficiently. 30 While the above description describes presently advantageous embodiments of the invention it is to be clearly understood that the invention is not limited thereto and can be carried out differently within the scope of the following claims. 35 Dr. SU/sb/cw P106621AU00 M1n n 12 11 The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference numerals in the following claims do not in any way limit the scope of the respective claims.

Claims

1. A laundry dryer with a fluff filter (6) and a cleaning device for the fluff filter (6), 5 characterized in that the cleaning device comprises a suction nozzle (11) for automatically aspirating fluff from the fluff filter (6).

2. The laundry dryer of claim 1 wherein the fluff filter (6) is circular, wherein the laundry dryer 10 further comprises a rotating drive for rotating the fluff filter (6) relatively to the suction nozzle (11) about a central axis (9), and in particular wherein the fluff filter (6) is rotatable and the suction nozzle (11) is stationary. 15

3. The laundry dryer of claim 2 wherein an opening (14) of the suction nozzle (11) extends from the central axis (9) to a periphery of the fluff filter (6).

4. The laundry dryer of any of the preceding claims wherein the fluff filter (6) is arranged at a door 20 (2) of the laundry dryer.

5. The laundry dryer of any of the preceding claims adapted to lead processing air carrying fluff from an entry side (16) through fluff filter (6), wherein the suction nozzle (11) is arranged at the entry side (16) of 25 the fluff filter (6).

6. The laundry dryer of claim 5 further comprising a blowing nozzle (18) for blowing air against the fluff filter (6), wherein the blowing nozzle (18) is arranged on an exit side opposite to the entry side (16) 30 of the fluff filter, wherein the blowing nozzle (18) is arranged opposite to the suction nozzle (11).

7. The laundry dryer of any of the preceding claims comprising a suction device (22) connected to the suction nozzle (11) for generating an underpressure in 35 the suction nozzle (11), wherein the suction device (22) comprises a separator for depositing fluff and a fluff container (24) for receiving the deposited fluff. Dr. SU/sb/cw P106621AU00 01.02.2012 13

8. The laundry dryer of claim 7 wherein the separator comprises a compression device (26, 33, 54) for compressing the separated fluff.

9. The laundry dryer of claim 8 wherein the 5 compression device (26, 33, 54) comprises a plunger (26) and a separator filter (28), wherein air coming from the suction nozzle (11) is led through the separator filter (28), and wherein the plunger (26) is adapted to be moved along the separator filter (28) for wiping off fluff from 10 the separator filter (28).

10. The laundry dryer of claim 9, wherein the plunger (26) is adapted to be moved against a closing plate (54), in particular a slideable or pivotal closing plate (54), in order-to compress fluff wiped off from the 15 separator filter (28) between the plunger (26) and closing plate (54), and wherein the closing plate (54) is adapted to be opened after compressing the fluff for pushing the compressed fluff into the fluff container (24). 20

11. The laundry dryer of claim 10, wherein the separator is designed such that, after pushing the compressed fluff into the fluff container (24), the plunger (26) is arranged flush to a filling opening (53) closed by the closing plate (54), such that when closing 25 the closing plate (54) fluff adhering to the plunger (26) is wiped off by a closing motion of the closing plate (54).

12. The laundry dryer of any of the claims 9 to 11, wherein the suction device (22) is adapted to lead 30 air from the suction nozzle (11) - along a first direction through the separator filter (28) before wiping off the fluff, and - along a second direction, with the section direction being opposite to the first direction, through 35 the separator filter (28) after wiping off the fluff.

13. The laundry dryer of any of the claims 9 to 12, further comprising closing means (33, 44) arranged Dr. SUlsb/cw P106621AU00 ni012212 14 at the plunger (26), which open and close, respectively, at least one air opening (40, 41, 56) for controlling the air as a function of a position of the plunger (26).

14. The laundry dryer of any of the claims 7 5 to 13 wherein the fluff container (24) is adapted to start to open when being full of fluff, wherein a sensor for detecting an opening of the fluff container (24) is arranged at the fluff container (24).

15. The laundry dryer of any of the preceding 10 claims wherein an opening (14) of the suction nozzle (11) is arranged no more than 4 mm from the fluff filter (6).

16. The laundry dryer of any of the preceding claims adapted to trigger a cleaning of the fluff filter (6) by means of the suction nozzle (11) towards an end of 15 a drying program.

17. The laundry dryer of any of the preceding claims comprising several fluff filters (6, 6'), arranged behind each other in an air flow (L), with a suction nozzle (11) attributed to each fluff filter (6, 6'). 20

18. The laundry dryer of any of the preceding claims wherein the fluff filter (6) is a ribbon with rolled-up end sections. Dr. SU/sb/cw P106621AU00 01.02.2012