EP2407588B1

EP2407588B1 - Laundry dryer including a filtering cartridge and method for the production of such a cartridge

Info

Publication number: EP2407588B1
Application number: EP10169798.5A
Authority: EP
Inventors: Luciano Sartor; Sergio Pillot
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2010-07-16
Filing date: 2010-07-16
Publication date: 2013-12-18
Anticipated expiration: 2030-07-16
Also published as: EP2407588A1

Abstract

The present invention relates to a method for the production of a filtering cartridge (2) for laundry dryers (1) comprising a hollow shell (21). The hollow shell (21) includes a filtering net (23) and two complementary pieces or half-shells (22a, 22b) which are hinged one to the other so that they can rotate one with respect to the other around an axis (H). The net (23) is corrugated and defines a plurality of substantially parallel channels (30). The method of the invention comprises the steps of: disposing the net (23) in a mould (40) suitable to realize the hollow shell (21), the net (23) being located in the mould in such a way that, when the filter cartridge (2) is moulded, this net (23) covers at least partially both the two complementary pieces or half-shells (22a, 22b) and the connecting region (29) therebetween, so as to act as the hinge element between the two complementary pieces or half-shells (22a, 22b), and in such a way that the channels (30) are be disposed substantially parallel to the rotation axis (H); injecting the plastic material forming the hollow shell (21) on the mould (40), so as to partially embed the net (23) and to form the two complementary pieces or half-shells (22a, 22b) and the connection therebetween. The invention also relates to a laundry dryer (1) including the filter cartridge (2) so obtained.

Description

The present invention relates to a laundry dryer including a filtering cartridge, especially designed to maximize the filtering surface. Method of the invention relates to the production of such a filtering cartridge having relatively few steps.
As is known in the art, present laundry driers generally comprise a substantially parallelepiped-shaped outer box casing; a rotatable drum, typically cylindrical and hollow, for housing the laundry to be dried, and which is housed in rotating manner inside the casing to rotate about its longitudinal axis, directly facing a opening to load/unload the laundry formed in the front face of the casing. A door is generally hinged to the front face of the casing to rotate to and from a closing position in which the door rests completely against the casing to close the opening in the front face of the casing and seal the rotatable drum; and an electric motor assembly for rotating the drum about its longitudinal axis inside the casing.
Laundry driers of the above type also generally comprise a hot-air circuit designed to circulate inside the rotatable drum a stream of hot air with a low moisture content so as to rapidly dry the laundry contained in the drum.
The hot air might circulate in an open circuit, i.e. the hot humid air after having passed through the drum is vented outside, or a closed-circuit might be included, in which the hot-air circuit comprises an air recirculating conduit having its two ends connected to the rotatable drum, on opposite sides of the latter, and a fan located along the re-circulating conduit produces an airflow which flows through the rotatable drum. The humid air exiting the drum is dehumidified by circulating into a condenser where the moisture is removed out. The dry air so obtained is then heated and then recirculated back through the laundry in the drum and the process begins again.
To avoid fluff and/or lint particles removed from the laundry by the air flow to obstruct the venting pipe or to reach and clog up the centrifugal fan, tumble dryers also comprises at least one filtering element - commonly known as "lint filter" - which is placed along the air conduit, typically upstream of the centrifugal fan if the latter is present. The lint to be filtered is comprised of fibres found on the clothes that become loosened and fall off during the drying process, so that they are transported by the air flow which traverses the drum. Lint filters are preferably adapted to be easily removed from the dryer in order to wipe away the trapped lint, then replaced for the next drying cycle.
Lint filters are commonly formed with a hard or semi-flexible plastic frame that helps them maintain their shape. Within the frame a small screen or net is placed, which serves to filter the lint. These lint filters are inserted into compartments or seats within the clothes dryer that are designed specifically to fit lint filters recommended by the manufacturer.
Once lint filters are slid into their special compartments or seats, they filter the hot and humid air exiting the drum and they retain the lint of fluff removed from the laundry by the stream of air, avoiding in this way that the lint could be drifted to the rest of the hot-air circuit. Without a lint filter, lint could become trapped inside the hot-air circuit, and can cause clothes to dry less quickly and can also create a fire hazard.
The European patent EP 0106289 describes a laundry dryer having a perforated drying drum, an electric blower, at least one electric heater element, an arrangement of air ducts for circulating heated air through the drum for drying the laundry contained therein, and a lint retaining filter disposed in an air duct is provided with a monitoring device for detecting the operative condition, i.e. the state of clogging of the filter. The monitoring device includes at least two sensor electrodes disposed in spaced relationship on or adjacent the filter so as to be short-circuited by moist lint accumulating thereon. The sensor electrodes are connected to signalling means and/or to an electric circuit controlling operation of the electrical components of the dryer, so as to indicate clogging of the filter through said signalling means and/or to de-energize the electrical components in a clogged condition of the filter.
The patent GB 2116068 discloses an air filter for a tumble drier of hollow wedge-like form which comprises two identical moulded frames bridged by plastics mesh and each comprising a single upstanding flange, extending along one edge and halfway along an adjacent edge, and a pair of spaced flanges extending along the opposite edge and half way along edge. In their operative position the two frames engage face to face, with respective flanges locating between flanges on the other frame. The frames hinge together at put-fit connections are held in their operative relationship by push-fit connectors and can be opened out to enable fluff to be removed. Pegs serve as handles.
The filtering surface of the filters disclosed in the above GB and EP documents is flat.
In the patent GB 2091123 an air filter, for use in a clothes dryer using a current of air, comprising two sieves connected by a hinge, is described. In use the filter is closed so that the sieves are almost parallel and act in series. The upstream sieve may be corrugated and coarser in mesh than the flat downstream sieve. The filter is located in the clothes defector immediately downstream of the rotary drying drum to prevent lint from reaching the condenser.
The manufacturing process to realize the air filter of GB 2091123 is relatively complex due to the fact that different sieves have to be positioned in the mould in order to obtain the finished product. Indeed, the plastic hinge physically separates the two sieves requiring the presence of at least two different separated elements to be positioned in their respective frames.
Aim of the present invention is therefore to provide a laundry drier featuring a simple and more efficient air filtering system, capable of significantly improving the overall area of the filtering surface and simplifying the manufacturing steps for its production.
According to the present invention, there is provided a method to produce a filtering cartridge for laundry driers as claimed in Claim 1 and preferably, though not necessarily, in any one of the dependent Claims.
According to the present invention, there is also provided a laundry dryer including a filtering cartridge as claimed in Claim 4 and preferably, though not necessarily, in any one of the dependent Claims.
A non-limiting embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a functional schematic diagram of a laundry drier provided with a filtering cartridge realized in accordance with the teaching of the present invention;
Figure 2 shows a section view, with parts removed for clarity, of a laundry drier provided with a filtering cartridge realized in accordance with the teachings of the present invention;
Figure 3 shows an enlarged detail of the laundry drier of Figure 2;
Figure 4 is a perspective view of a filtering cartridge realized according to the invention in a closed configuration;
Figure 5 is a frontal view of the filtering cartridge of Figure 4 in an opened configuration;
Figures 6 and 7 are two side views, the second also in cross-section, in an opened configuration, of the filtering cartridge of Figure 4;
Figure 8 is a perspective view of the filtering cartridge of Figure 4 in an opened configuration;
Figure 9 is a cross-sectional lateral view of the filtering cartridge of Figure 4 in closed configuration;
Figures 10 -12 schematically represent, in cross sectional lateral views, different steps of the method of the invention;
Figure 13 is a schematic cross sectional lateral view of the filtering cartridge of Fig. 4 in an opened configuration.

With reference to Figures 1 and 2, with numeric reference 1 as a whole a laundry drier is indicated.
The laundry dryer 1 comprises preferably, though not necessarily: an outer box casing 3 having preferably the shape of a parallelepiped (outer box casing 3 has been only partially shown in Fig. 2); a drum 4, having for example a hollow cylindrical shape, opened at its bases for housing the laundry 100 to be dried, and which is fixed in axially rotating manner inside the casing 3, for example rotatable around its longitudinal axis L, directly facing an opening 3a to load/unload the laundry L formed in the front face of casing 3; and a door 5 (schematically represented in Fig. 2) hinged to the front face of casing 3 to rotate to and from a closing position in which the door 5 rests completely against the casing to close the opening 3a in the front face of the casing, so as to seal the rotatable drum 4 from the external of the laundry drier 1.
Casing 3, rotatable drum 4, and door 5 are commonly known parts in the industry, and therefore not described in detail.
Laundry drier 1 also preferably comprises: a motor assembly (not shown in the enclosed Figures) adapted for rotating the rotatable drum 4 about its longitudinal axis L inside the casing 3; and a hot-air circuit, preferably, but not necessarily, comprising an air recirculating conduit having its two ends connected to the rotatable drum 4. The recirculating conduit is designed to circulate through the rotatable drum 4 a stream of hot air preferably having a low moisture level, and which flows over and dries the laundry 100 inside drum 4. The air flow within the drum 4 and the recirculating conduit of the laundry dryer 1 is schematically shown by means of a plurality of arrows 200 in Figs. 1, 2 and 3.
Advantageously, the hot-air circuit provides for feeding heated air into the rotatable drum 4 in correspondence of the base of the drum 4 opposite to the opening 3a, where it flows over, to dry the laundry 100 inside the drum, and then it exits the drum 4 in correspondence of the door 5 of the laundry drier 1. Advantageously the humid air is sucked from the drum interior preferably by a blower 15. The humid air which has left the drum 4 is preferably conveyed towards a condenser 12 which includes a plurality of channels: by flowing through these channels, which are in thermal contact with adjacent channels in which air at room-temperature is circulating, the humid air coming from the drum is dehumidified, the moisture it contains is condensed, and in addition it is refrigerated. The cool dry air leaving the condenser 12 is then preferably directed to a heat resistance 50 (or other heating means, for example a heat pump) in order to be heated prior to re-entering into drum 4. The air that then enters in the drum is again dry and warm, to efficiently dry the laundry 100. According to a preferred embodiment, the condenser 12 is located in correspondence of a basement 9 of the dryer 1.
In a further embodiment, not illustrated, the air recirculating conduit is not provided, and the humid air exiting the drum is directly discharged outwards the drier.
The laundry dryer 1 comprises a filtering cartridge 2 (or filtering element, or filter), advantageously, but not necessarily, substantially wedge-shaped. Preferably, the filtering cartridge 2 is located in a seat 11 in proximity of the door 5, for example a seat in the form of a slit can be realized in the peripheral edge of the laundry loading/unloading opening 3a. The humid air exiting the drum 4 crosses the filtering cartridge 2, preferably before entering the condenser 12 (if the latter is provided), as it will be better detailed below.
With reference to the enclosed Figures, the filtering cartridge 2 comprises a supporting plate 20, preferably substantially flat, and advantageously made of rigid or semi-rigid plastic material, which is structured for being insertable in a removable manner into the seat 11, so as to completely close the latter.
Advantageously, the filtering cartridge 2 comprises a hollow shell 21, preferably substantially bag-shaped and advantageously made of rigid or semi-rigid plastic material, which overhangingly protrudes from the rear face of the supporting plate 20, so as to extend inside the starting section of the hot-air circuit of the dryer in the direction of the air flow when the filtering cartridge 2 is inserted into the seat 11.
Hollow shell 21 advantageously comprises two complementary pieces or half- shells 22a and 22b which are laterally hinged to one another, preferably, though not necessarily, in correspondence to the opposite side of supporting plate 20, so that the hollow shell 21 is openable in a book-like manner (see Figures 5 to 8), i.e. it can be moved from a closed configuration, shown in Figs. 4 and 9, to an opened configuration, shown in Figs. 5 to 8, so as to allow the removal of lint of fluff accumulated therein.
The rotation axis around which the two pieces or half-shells can rotate so as to move from one configuration to the other is called H in Figs. 5 and 8. In Fig. 13 arrows 300 schematically represent the movement to be performed by the two half-shells in order to move from the open to the closed configuration.
Supporting plate 20 is advantageously centrally provided with at least a throughout opening 20a (see Figures 3, 4, 7, 8, 9) through which the airflow exiting the drum 4 can enter into the hollow shell 21.
Preferably, but not necessarily, supporting plate 20 may be divided in two portions 20' and 20" (the two portions are schematically illustrated for example in Figs. 12 and 13), each attached to respective half- shell 22a, 22b; the two portions 20', 20" fit one in the other in a complementary way so as to form a single element, i.e. the plate 20, when the filtering cartridge 2 is in the closed configuration.
Advantageously the two half- shells 22a and 22b comprise fastening means adapted for fixing them one another in the closed configuration; these fastening means comprise, for example, one or more protrusions (in the example illustrated in the enclosed figures there is only one protrusion numbered 400a), protruding from one of the portions of the supporting plate 20 and adapted to be removably housed, preferably by snap-fittings, in one or more seats (in the example illustrated in the enclosed figures there is only one seat numbered 400b) obtained in the other portion of the supporting plate 20.
Advantageously, each half- shell 22a, 22b preferably also includes lateral walls 9a, 10a; 9b, 10b substantially perpendicular, when the half-shells are in the closed configuration shown in Figs. 4 and 9, to the supporting plate 20; preferably, but not necessarily, if the supporting plate 20 comprises the above indicated two portions 20' and 20", the lateral walls 9a, 10a; 9b, 10b protrudes from the respective portion 20', 20" of the supporting plate 20 along the longitudinal extension of each half-shell, for example substantially perpendicular to the respective portion 20', 20" so as to form a frame with an open base (i.e. the portion of supporting plate and lateral walls defines three sides of a frame for each half-shell, having the shape substantially of a Greek letter π). Each frame in turn substantially defines an inner surface, i.e. the surface which is surrounded by the mentioned three sides.
In a further embodiment, not illustrated, the supporting plate 20 comprises a single portion from which the lateral walls of one of the half-shells protrude, while the other half-shell, comprises the lateral walls, but doesn't comprise a portion of the supporting plate.
According to the invention, both half- shells 22a, 22b are covered, preferably for most of their extension, with an air-permeable net (preferably, but not necessarily a close-mesh net) or screen, or grille, or gauze patch 23 (in the following for simplification only called "net", but this word encompasses all the above mentioned terms and more in general it indicates a device adapted for allowing the passage of air but to impede the passage of lint, fluff, or other solid bodies) properly dimensioned for restraining fluff and/or lint particles within the hollow shell 21.
According to a preferred embodiment of the invention, each half shell is realized substantially by the open-ended frame (e.g. the above mentioned frame which includes the portion 20' (or 20") of supporting plate 20 and the two lateral walls 9a, 10a (or 9b, 10b)) on which a portion of net 23 (see for example fig. 13) is connected, i.e. no additional structural element is needed. The lateral walls increase the overall rigidity of the filtering cartridge 2.
According to an advantageous embodiment of the invention, each half-shell 22a (22b) may include one or more reinforcing elements, for example one or more rods 25, preferably substantially parallel to the respective lateral walls, to increase the strength of the filtering cartridge 2. In case of more than one rod, they are preferably, but not necessarily, arranged substantially in a grid. The rod(s) 25 defines at least one throughout opening 21a (see Fig. 4 in which a plurality of openings 21a and rods 25 are realized on each half-shell) on top of which the net 23 is located, in order to cover at least partially the same. Preferably, the net 23 covers all openings 21a realized in the two half-shells.
As visible for example in Figs. 2 and 3, the humid air (schematically represented by the arrows 200) exiting the drum 4 enters the filtering cartridge 2 through the openings 20a in the supporting plate 20, and it exits the filtering cartridge 2 via the openings in the half shells 22a, 22b (i.e. through the net 23, which includes openings through which the air can flow, and, when present, through the openings 21a). Advantageously the air exits the filtering cartridge 2 also in the connecting region between the two half-shells as better detailed below.
It is underlined that the net 23 is not only a filtering cartridge to retain lint, but also a connecting element between the two half- shells 22a, 22b serving locally as an hinge element allowing the mutual bending of the half shells 22a, 22b one with respect to the other and thus the opening/closing of the shell 21.
Net 23 is preferably realized in a single piece covering at least partially both half- shells 22a, 22b and the connecting region therebetween.
Advantageously, in the closed configuration, each half-shell has one side attached or connected to the supporting plate 20, from which the lateral walls extend, while the opposite side is free, i.e. each half-shell defines a frame open on one side, and the two open sides are substantially facing one to the other. The net 23 is disposed between the two half-shells and covers at least partially both inner surfaces of the same: for example, if the supporting plate comprises the two portions 20' and 20", starting from the side of the first half-shell 22a attached to the portion 20' of the supporting plate 20, the net 23 extends covering the inner surface of this first half-shell 22a till it reaches the opposite side of the same, it then forms a fold which serves as a hinge between the two half-shells, and continues to extend covering the inner surface of the second half-shell 22b starting from its free side till it reaches the side of this second half-shell 22b which is attached to the second portion 20" of supporting plate 20.
The lateral walls 9a, 10a; 9b, 10b in the closed configuration preferably mutually overlap, e.g. the lateral wall 9a (10a) of half shell 22a and the lateral wall 9b (10b) of half shell 22b are superimposed along a direction substantially perpendicular to the longitudinal extension of the half-shells and also substantially perpendicular to the supporting plate 20.
In order to enhance the stability of the cartridge in the closed configuration, the half- shells 22a, 22b might preferably include centring means, adapted for facilitating their positioning in a closed condition, comprising for example a seat and a rib, respectively, which engages one into the other when the cartridge 2 is closed. Such seat and corresponding rib might be formed in the respective lateral wall of the half shells. As shown in Figs. 4, 5, 6 and 8, in a preferred embodiment of the invention, ribs 18 are formed on lateral walls 9b and 10b of one of the half-shells, and corresponding seats 17 are formed on lateral walls 9a and 10a of the other half shells.
In the opened configuration, where the two half-shell are disposed one as the geometrical extension of the other with a gap therebetween, which is called the connecting region 29, the net 23 preferably covers both inner surfaces of the half-shells as a single unitary element and it also covers the gap (i.e. the connecting region) which is formed between the free sides of the two half-shells.
The net 23 can advantageously be advantageously attached also to lateral walls 9a, 10a (9b, 10b).
In a further embodiment, the net 23 may be realized in two (or more) pieces which partially overlap in a given region of the filter so as to form the hinge between the two half-shells.
Net 23 can be preferably realized in plastic, such as polypropylene or polyester, however also metal nets 23 are covered by the invention.
The hinge connection between the two half-shells can be realized either by only the net 23 as shown in the appended figures or, in addition to the net, one or more connecting stripes or bands or other connecting element (embodiment not shown) which are realized integral with the half-shells can be present. The stripes extend with one of their ends from the free end of the first half-shell opposite to the plate 20 and connect with their opposite end to the second half-shell in correspondence of the free end of the latter.
With reference to Figs. 2 and 3, after having entered into the hollow shell 21 through opening 20a on supporting plate 20, the airflow (represented by the arrows 200) comes out form hollow shell 21 through the net 23 and, when present, also through openings 21 a on the two half- shells 22a and 22b of hollow shell 21, leaving fluff and/or lint particles (not represented) within hollow shell 21. Air exits therefore also from the connecting region 29 between the two half-shells, due to the fact that this connecting region is covered by the net 23, extending therefore the filtering area with respect of a filter in which the connecting region has no openings.
With reference to the enclosed Figures, in the example shown the supporting plate 20 is advantageously substantially rectangular in shape, and is preferably properly bend to match the profile of the annular frame delimiting the laundry loading/unloading opening 3a, i.e. of the peripheral edge of the laundry loading/unloading opening 3a formed in the front face of casing 3.
Advantageously, opening 20a on supporting plate 20 is preferably, though not necessarily, completely covered by a grille 500 made in one piece with the supporting plate 20 itself, adapted for allowing the passage of the air exiting the drum 4.
Hollow shell 21 has preferably, though not necessarily, a substantially V-shaped or substantially trapezoidal cross section (see Fig. 9) when the shell is closed.
According to a preferred characteristic of the invention, the net 23 is not flat, on the contrary it is corrugated.
Advantageously substantially any net cross section is acceptable as long as the total filtering surface of the net 23 of the invention is larger than a corresponding surface of a flat net which extends over the same area of the net 23 defined by the sum of the inner areas of the two half- shells 22a, 22b and the area of the connecting region therebetween. In other words, the cross section of the net 23 preferably comprises two distinct non negligible components, one along the longitudinal extension of the half-shell and the second perpendicular to it.
As it can be clearly seen for example in fig. 9, the cross section of the net 23 advantageously includes a plurality of corrugations which defines alternating peaks 32b and valleys 32a which might have any form, e.g. the net 23 can have a triangular cross section, a saw-tooth cross section, a wave-like cross section or a sinusoidal cross-section, a square-wave cross section, etc. In all these configurations the curve defined by the net's cross-section can be virtually decomposed in two components, one parallel to the longitudinal extension of the net and one perpendicular to it.
The peaks 32b and valleys 32a realized in the net 23 form a plurality of channels 30 one substantially parallel to the other. According to the invention, these channels are advantageously disposed substantially parallel to the rotation axis H of the two half- shells 22a and 22b so that rotation of the same is facilitated; in other words the corrugated shape of the net 23 (comprising the longitudinal channels 30), and its particular positioning (with the channels 30 substantially parallel to the rotation axis H of the two half-shells) makes it very easy the closure of the filtering cartridge 2 form the opened condition of Figure 5 to the closed condition of Figure 4.
The net 23, thanks to its corrugated cross section and to the fact that it covers not only the half-shells but also the connecting region 29, provides a much larger filtering surface than the standard filter including a flat net, without increasing the overall dimensions of the filtering cartridge 2 itself. Indeed, it is relevant to note that the achieved increased filtering surface does not mean an increase in any of the dimensions of the two half-shells.
Therefore, even in case some lint or fluff becomes attached to the net 23, due to its increased proportions normal drying operation can be ensured for a longer time; in other words the air flux through the net 23 remains adequate for a longer time than if the net would be flat, since the filtering surface of the net is enhanced with respect to a flat net.
The particular configuration of the filter cartridge 2 of the invention allows a simple method of construction of the same. A possible embodiment of the method of the invention is disclosed with reference to Figures 10-13.
According to the method of the invention, the net 23, which is realized as a single piece either of plastic (polymeric) or of metal, or as a combination of overlapping pieces, is disposed in a mould 40 (Fig. 10) in which the plastic (polymeric) material forming the plate 20 and the half shells 22a and 22b is then injected; in the second step of the method the mould 40 is closed (Fig. 11).
In case the half-shells include also rods 25, the material forming the same is also injected at the same in the mould 40 (step not visible in the Figures).
The positioning of the net 23 in the mould 40 is such that on the finished product, the net 23 covers at least partially the two half-shells and the region 29 of connection therebetween. In addition, the net 23 is positioned in the mould in such a way that the channels 30 formed in the net 23 are positioned so as to result parallel to the rotation axis H around which the two pieces or half-shells can rotate.
When the polymeric material is solidified, the filtering cartridge 2 is then removed from the mould (Fig. 12), and the two half shells 22a and 22b can be rotated one with respect to the other around region of connection 29, as schematically illustrated in Figure 13.

Claims

A method for the production of a filtering cartridge (2) for a laundry dryer (1) comprising a hollow shell (21) including a filtering net (23) and two complementary pieces or half-shells (22a, 22b) which are hinged one to the other so that they can rotate one with respect to the other around an axis (H), said net (23) being corrugated and defining a plurality of substantially parallel channels (30), characterized in that said method comprises the steps of:
- disposing said net (23) in a mould (40) suitable to realize said hollow shell (21), said net (23) being located in the mould (40) in such a way that, when the filter cartridge (2) is moulded, said net (23) covers at least partially both said two complementary pieces or half-shells (22a, 22b) and the connecting region (29) therebetween, so as to act as a hinge element between said two complementary pieces or half-shells (22a, 22b), and in such a way that said channels (30) are disposed substantially parallel to said rotation axis (H);

- injecting a plastic material forming said hollow shell (21) in said mould (40), so as to at least partially embed said net (23) and to form said two complementary pieces or half-shells (22a, 22b).
The method according to claim 1, wherein said cartridge (2) comprises a supporting plate (20) and the hollow shell (21) which protrudes from one of the faces of the supporting plate (20), said method comprising the step of moulding said supporting plate (20) and said hollow shell (21) in a single injection moulding step.
The method according to claim 1 or 2, wherein said net (23) is realized in a single piece.
A laundry dryer (1) including a filtering cartridge (2) comprising a hollow shell (21) including a filtering net (23) and two complementary pieces or half-shells (22a, 22b) which are laterally hinged one to the other so that said two complementary pieces or half-shells (22a, 22b) can rotate one with respect to the other around an axis (H), characterized in that said filtering net (23) covers at least partially both said two complementary pieces or half-shells (22a, 22b) and the connecting region (29) therebetween, so as to act as the hinge element between said two complementary pieces or half-shells (22a, 22b), said net (23) being corrugated and defining a plurality of substantially parallel channels (30) disposed substantially parallel to said rotation axis (H).
The laundry dryer (1) according to claim 4, in which said net (23) is realized in a single piece.
The laundry dryer (1) according to claim 4 or 5, in which each of said two complementary pieces (22a, 22b) comprises at least a rod (25) which defines an opening (21a), said openings (21a) being completely covered by said net (23).
The laundry dryer (1) according to any of claims 4-6, including a plurality of stripes or bands or connecting elements connecting said two complementary pieces (22a, 22b) in correspondence of their free-ends opposite to said supporting plate (20).
The laundry dryer (1) according to any of claims 4-7, wherein said net (23) comprises a substantially triangular-shaped cross section.
The laundry dryer (1) according to any of claims 4-8, wherein said net (23) comprises a substantially wave-like cross section.
The laundry dryer (1) according to any of claims 4-9, wherein said net (23) is made of polymeric material.
The laundry dryer (1) according to any of claims 4-10, wherein said half-shells (22a, 22b) comprise fastening means adapted for fixing them one another in a closed configuration.
The laundry dryer (1) according to claim 11, wherein said fastening means comprise one or more protrusions (400a) protruding from one of said half-shells (22a) and adapted to be removably housed in one or more seats (400b) obtained in the other half shell (22b).
The laundry dryer (1) according to any of claims 4-10, wherein said half-shells (22a, 22b) include centring means adapted for facilitating their positioning in a closed configuration.
The laundry dryer (1) according to claim 13, wherein said centering means comprises one or more seats (17) provided in one of said half-shells and a one or more corresponding ribs (18) provided in the other half-shells, which engages one into the other when said filtering cartridge (2) is closed.
The laundry dryer (1) according to any of claim 4-14 including:
- a casing (3);

- a rotatable drum (4) for housing the laundry to be dried and which is fixed in an axially rotating manner inside the casing (3), directly facing a laundry loading/unloading opening (3a) formed in the front face of the casing (3);

- a door (5) hinged on the front face of the casing (3) to close the laundry loading/unloading opening (3a);

- an air circulating conduit by which the air enters and exits the drum (4), an inlet of the air circulating conduit comprising a seat (11) formed in the peripheral edge of the laundry opening (3a);
wherein said filtering cartridge (2) is inserted in a removable manner into said seat (11).