Laundry Dryer

Laundry dryer (1) comprising an outer casing (2) having a front wall (2a) provided with a laundry loading/unloading pass-through opening, and an air-filtering cartridge (15) which is fitted in removable manner into an air-vent (10) which is passed through by a laundry drying airflow (f). the air-filtering cartridge (15) comprises a first substantially bag- or pocket-shaped, air-filtering shell or vessel (20, 120) which is dimensioned for being inserted/plugged into said air-vent (10) and is structured to restrain the fluff and/or lint particles in suspension into the airflow (f); the air-filtering cartridge (15) furthermore comprising a second substantially bag- or pocket-shaped, air-filtering shell or vessel (30, 130) which is fitted/recessed into said first air-filtering shell or vessel (20, 120) so as to be crossed by substantially the same airflow (f) that crosses the first air-filtering shell or vessel (20 120), is structured to restrain the fluff and/or lint particles in suspension into the airflow (f), and is mechanically coupled to said first air-filtering shell or vessel (20, 120) in sliding manner.

The present invention relates to a laundry dryer.

More in particular, the present invention relates to a rotary-drum household laundry dryer to which the following description refers purely by way of example without implying any loss of generality.

As it is known, rotary-drum household laundry dryers currently on the market generally comprise: a substantially parallelepiped-shaped, outer boxlike casing structured for resting on the floor; a substantially cylindrical rotatable drum which is structured for housing the laundry to be dried and which is housed in axially rotating manner inside the casing so to rotate about a substantially horizontally-oriented longitudinal reference axis, directly facing a laundry loading/unloading opening formed in the front wall of the casing; a porthole door hinged to the front wall of the casing to rotate to and from a closing position in which the door rests completely against the front wall of the casing to close the laundry loading/unloading opening and airtight seal the rotatable drum; an electrically-powered motor assembly which is housed inside the casing and is structured for driving into rotation the rotatable drum about its longitudinal reference axis; a closed-circuit, hot-air generator which is housed inside the casing and is structured to circulate inside the rotatable drum a stream of hot air which has a very low moisture content and flows through the rotatable drum and over the laundry inside the drum to rapidly dry the laundry; and finally an electronic central control unit which controls both the motor assembly and the hot-air generator to perform, on command, one of the user-selectable drying cycles stored in the same central control unit.

In most of the rotary-drum household laundry dryers currently on the market, the rotatable drum furthermore consists in a substantially cylindrical, rigid tubular body which is generally made of metal material and extends substantially horizontally inside the boxlike casing, locally aligned to the laundry loading/unloading opening. This rigid tubular body may be furthermore structured for resting on a number of idle supporting rollers which are arranged at the two axial ends of the tubular body locally parallel to the drum longitudinal reference axis, and are fixed to the boxlike casing in free revolving manner so as to allow the tubular body to freely rotate about its horizontally-oriented longitudinal reference axis. The circular front rim of the tubular body surrounds the laundry loading/unloading opening and is coupled in substantially airtight and axially rotating manner to the front wall of the boxlike casing; whereas the circular rear rim of the tubular body abuts against the rear wall of the boxlike casing and is coupled in substantially airtight and axially rotating manner directly to said rear wall.

The closed-circuit, hot-air generator in turn comprises: an air recirculating conduit which extends on the bottom of the boxlike casing and has a first end directly connected to a first air-vent realized in the rear wall of the boxlike casing, within the perimeter of the rear rim of the tubular body, and a second end directly connected to a second air-vent realized on the annular frame that delimits the laundry loading/unloading opening on the front wall of the casing; and an electrically-powered centrifugal fan which is located along the air recirculating conduit and is structured to produce an airflow which flows in closed loop through the air recirculating conduit and the rotatable drum.

The stream of hot air produced by the hot-air generator generally enters into the tubular body via the first air-vent realized in the rear wall of the boxlike casing, flows inside the tubular body for the entire length of the latter, and finally comes out of the tubular body via the second air-vent realized on the annular frame that delimits the laundry loading/unloading opening on the front wall of the casing.

The closed-circuit, hot-air generator furthermore comprises: an air-cooling device which is located along the air recirculating conduit, and is structured to cool the moist air arriving from the rotatable drum, so as to cause the condensation of the surplus moisture inside the airflow; an air-heating device which is located along the air recirculating conduit, downstream of the air-cooling device, and which is structured for heating the dehumidified airflow arriving from the air-cooling device and directed back to the rotatable drum, so that the airflow directed back into the rotatable drum is heated to a temperature preferably, though not necessarily, higher than or equal to that of the moist air flowing out of the same rotatable drum.

The closed-circuit, hot-air generator is finally provided with an air-filtering member which is arranged along the air recirculating conduit, upstream of the air-cooling device, to prevent the fluff and/or lint particles from reaching and clogging up the air-cooling device, the air-heating device and the centrifugal fan.

In some of the rotary-drum household laundry dryers currently on the market, the air-filtering member consists in a substantially wedge-shaped filtering cartridge which is fitted in removable manner into the air-vent realized on the annular frame that delimits the laundry loading/unloading opening on the front wall of the casing, so to cover/close the whole air-vent. Thus, when the porthole door is in the wide-opened position, the user is allowed to manually extract the wedge-shaped filtering cartridge from the air-vent realized on the annular frame that delimits the laundry loading/unloading opening for periodical cleaning.

DE8437357U1 discloses a wedge-like filtering cartridge for laundry driers which consists in a substantially bag- or pocket-shaped rigid shell which has a V-shaped cross section and is dimensioned for being inserted/plugged into the air-vent realized on the annular frame that delimits the laundry loading/unloading opening, so as to cover/close the whole air-vent. This bag-shaped rigid shell is furthermore divided into two or four valve-like pieces which are laterally hinged to one another, so that the rigid shell is openable in a book-like or leaflet-like manner. The flat central portion of each valve-like piece is provided with a large throughout opening which is completely covered with a close-mesh net capable to restrain the fluff and/or lint particles within the bag-shaped rigid shell.

Unluckily, periodical cleaning of the DE8437357U1 wedge-like filtering cartridge is particularly unpleasant to the user because the particular structure of the filtering cartridge allows the fluff and/or lint particles to accumulate on opposite faces of the inner and outer valve-like pieces, creating several problems at opening of the filtering cartridge.

Aim of the present invention is to provide a laundry dryer having an air-filtering cartridge which is easier to clean.

In compliance with the above aims, according to the present invention there is provided a laundry dryer having an air-filtering cartridge as claimed in claim1and preferably, though not necessarily, in any one of the dependent Claims.

With reference toFIGS. 1 and 2, reference number1indicates as a whole a rotary-drum household laundry dryer which comprises: a preferably, though not necessarily, parallelepiped-shaped, outer boxlike casing2which is structured for resting on the floor and is provided with reciprocally-faced, substantially vertically-oriented, front and rear walls2aand2b; a substantially cylindrical rotatable drum3which is structured for housing the laundry to be dried, and is fixed in axially rotating manner inside the boxlike casing2directly facing a laundry loading/unloading pass-through opening formed on the front wall2aof casing2; and a porthole door4hinged to the front wall2aof casing2so to be able to rotate about a preferably, though not necessarily, vertically-oriented reference axis, to and from a closing position in which the porthole door4rests completely against the front wall2ato close the laundry loading/unloading opening and substantially airtight seal the rotatable drum3.

Inside the boxlike casing2, the laundry dryer1additionally comprises an electrically-powered motor assembly5structured for driving into rotation the rotatable drum3about its longitudinal reference axis; a closed-circuit, hot-air generator6which is structured to circulate through the rotatable drum3a stream of hot air having a low moisture level, and which flows over and rapidly dries the laundry located inside the drum3; an electronic central control unit (not shown in the drawing) controls the motor assembly5, the hot-air generator6to perform, on command, one of the user-selectable drying cycles preferably, though not necessarily, stored in the same central control unit, a further control unit7may be provided for controlling the operation of compressor19.

With reference toFIG. 2, in particular, the rotatable drum3preferably consists in a substantially cylindrical-shaped, rigid tubular body3which is preferably made of metal material and extends inside the boxlike casing2coaxial to a preferably substantially horizontally-oriented, longitudinal reference axis L while remaining locally substantially aligned to the laundry loading/unloading opening on the front wall2aof the boxlike casing2. The substantially cylindrical-shaped, rigid tubular body3is furthermore preferably structured for resting on a number of idle supporting rollers8which are arranged approximately at the two axial ends of the tubular body3with their rotation axis locally substantially parallel to the longitudinal reference axis L of tubular body3, and are fixed to the boxlike casing2in free revolving manner so as to allow the tubular body3to freely rotate about its longitudinal reference axis L inside the boxlike casing2. Even if it is here described a drum supported by rotatable rollers, it should be understood that the present invention covers also an arrangement wherein the drum is supported by a shaft mechanically connected to the drum rear wall, i.e. the wall opposite to the drum front wall which is provided with an opening for loading/unloading laundry into/from the drum. Said shaft is also provided to rotate the drum.

The circular front rim3fof tubular body3surrounds the laundry loading/unloading opening realized on the front wall2aof boxlike casing2and is coupled in substantially airtight and axially rotating manner to the front wall2a, preferably with the interposition of a first circular sealing gasket. The circular rear rim3rof tubular body3instead abuts against the rear wall2bof boxlike casing2and is coupled in substantially airtight and axially rotating manner directly to said rear wall2bwith the interposition of a second circular sealing gasket. Front and rear circular sealing gaskets are therefore substantially coaxial to the longitudinal reference axis L of tubular body3.

The stream of hot air produced by the hot-air generator6preferably enters into tubular body3through the rear mouth of tubular body3, i.e. the mouth of tubular body3delimited by the rear rim3r, flows inside tubular body3for the entire length of the latter, and finally comes out of tubular body3through the front mouth of tubular body3, i.e. the mouth of tubular body3delimited by the front rim3f, or vice versa.

In other words, the stream of hot air produced by the hot-air generator6preferably enters into tubular body3via a first air-vent9which is incorporated in the rear wall2bof casing2locally aligned/faced to the rear mouth of tubular body3, i.e. within the perimeter of the rear rim3rof tubular body3, and comes out of tubular body3via a second substantially slot-shaped, air-vent10which is preferably incorporated in the annular frame that, on front wall2a, delimits the laundry loading/unloading opening of boxlike casing2.

With reference toFIGS. 1 and 2, the hot-air generator6in turn is structured for gradually drawing air from rotatable drum3; cooling down the air arriving from rotatable drum3so to extract and retain the surplus moisture in the air drawn from rotatable drum3; heating the dehumidified air to a predetermined temperature, normally higher than the temperature of the air from rotatable drum3; and finally feeding the heated, dehumidified air back into the rotatable drum3, where it flows over, to rapidly dry, the laundry inside the drum.

In other words, hot-air generator6provides for continually dehumidifying and heating the air circulating inside rotatable drum3to rapidly dry the laundry inside the drum, and substantially comprises:an air recirculating conduit11which has a first end in direct communication with, i.e. fluidly connected to, the air-vent9located in rear wall2bof casing2, and a second end in direct communication with, i.e. fluidly connected to, the air-vent10preferably located in the annular frame that delimits the laundry loading/unloading opening on front wall2a;an electrically-powered centrifugal fan12(part of its volute is shown inFIGS. 1 and 2) or other type of air circulating pump, which is located along recirculating conduit11to produce, inside recirculating conduit11, an airflow f which flows through rotatable drum3and over the laundry inside drum3;air-cooling device13which is located along the air recirculating conduit11preferably, though not necessarily, upstream of the centrifugal fan12, and is structured to cool the moist air arriving from rotatable drum3so as to cause the quick condensation of the surplus moisture inside the airflow f; andair-heating device14which is located along the air recirculating conduit11, downstream of the air-cooling device13and preferably also upstream of the centrifugal fan12, and which is structured for heating the dehumidified airflow f arriving from the air-cooling device13and directed back to rotatable drum3, so that the airflow f directed back into the rotatable drum3is heated to a temperature preferably, though not necessarily, higher than or equal to that of the moist air flowing out of the same rotatable drum3.

With reference toFIG. 2, the hot-air generator6lastly comprises a preferably substantially wedge-shaped, air-filtering cartridge15which is fitted in removable manner into the air-vent10preferably realized on the annular frame that delimits, on front wall2a, the laundry loading/unloading opening of casing2. This air-filtering cartridge15is dimensioned so as to cover/close the whole air-vent10, i.e. the entrance of air recirculating conduit11, and it is structured to restrain the fluff and/or lint particles in suspension into the airflow f so to prevent the same fluff and/or lint particles from reaching and clogging up the air-cooling device13, the air-heating device14and the centrifugal fan12located along the air recirculating conduit11.

With reference toFIGS. 1 and 2, in the example shown, in particular, the outer boxlike casing2preferably, though not necessarily, comprises a substantially parallelepiped-shaped lower supporting basement16which is structured for resting on the floor; and a substantially parallelepiped-shaped upper boxlike cabinet17which is rigidly fixed to the top of the lower supporting basement16and it is structured so as to house the rotatable drum3.

In other words, the rotatable drum3extends inside the upper boxlike cabinet17, immediately above the supporting basement16; the laundry loading/unloading opening of boxlike casing2is realized in the front wall of the upper boxlike cabinet17; and the porthole door4is hinged to the front wall of the same upper boxlike cabinet17.

The lower supporting basement16, in turn, is preferably, though not necessarily, structured for internally housing a central/intermediate section of air recirculating conduit11, and the air-cooling device13, the air-heating device14and the centrifugal fan12of hot-air generator6are preferably located inside said central/intermediate section of the air recirculating conduit11. Thus the lower supporting basement16is preferably, though not necessarily, structured for internally housing part of the hot-air generator6.

Preferably, though not necessarily, the lower supporting basement16is moreover structured to directly support the drum-supporting rollers8. In other words, the idle rollers8that support in free revolving manner the tubular body3are preferably fixed in axially rotating manner directly to the top of the lower supporting basement16.

With reference toFIGS. 1 and 2, the hot-air generator6preferably, though not necessarily, consists in a heat-pump type, closed-circuit, hot-air generator6, thus it is provided with a heat-pump circuit18which comprises a first and a second air/refrigerant heat exchanger, both located inside the air recirculating conduit11preferably upstream of the centrifugal fan12.

The first air/refrigerant heat exchanger, traditionally referred to as the “evaporator” of the heat-pump circuit, is located inside the air recirculating conduit11, and it is structured to remove/absorb heat from the airflow f arriving from rotatable drum3, thus forming the air-cooling device13of the hot-air generator6. The second air/refrigerant heat exchanger, traditionally referred to as the “condenser” of the heat-pump circuit, is instead located inside the air recirculating conduit11downstream of the first air/refrigerant heat exchanger13, and it is structured to release heat to the airflow f arriving from the first air/refrigerant heat exchanger13, thus forming the air-heating device14of the hot-air generator6.

In the example shown, in particular, the first and second air/refrigerant heat exchangers13and14are arranged one after the other along the section of air recirculating conduit11which is integrated into the lower supporting basement16of boxlike casing2.

In addition to the above, the heat-pump circuit18furthermore comprises: an electrically-powered refrigerant compressing device19which is interposed between the refrigerant-outlet of air/refrigerant heat exchanger13and the refrigerant-inlet of air/refrigerant heat exchanger14, and it is structured for compressing the gaseous-state refrigerant directed towards heat exchanger14so that refrigerant pressure and temperature are much higher at the refrigerant-inlet of heat exchanger14than at the refrigerant-outlet of heat exchanger13; and an expansion valve or similar known passive/operated refrigerant expansion device (for example a capillary tube, a thermostatic valve or an electrically-controlled expansion valve) which is interposed between the refrigerant-outlet of air/refrigerant heat exchanger14and the refrigerant-inlet of air/refrigerant heat exchanger13, and it is structured so as to cause a rapid expansion of the refrigerant directed towards the air/refrigerant heat exchanger13, so that refrigerant pressure and temperature are much higher at the refrigerant-outlet of heat exchanger14than at the refrigerant-inlet of air/refrigerant heat exchanger13.

According to a different embodiment not shown, the hot air generator6may comprise an electric heater as air-heating device14and an air-air type heat exchanger as air-cooling device13, where the airflow f is cooled by air taken from and exhausted to the environment surrounding the laundry machine. An appropriate air pumping device is further arranged to pump ambient air through the air-air type heat exchanger.

With reference toFIGS. 1 and 2, the centrifugal fan12of hot-air generator6, in turn, is preferably, though not necessarily, located on the back of the supporting basement16, i.e. on the rear wall2bof the boxlike casing2, and it is structured so as to produce an airflow f that flows from the central/intermediate section of the air recirculating conduit11to the air-vent9located in rear wall2bof casing2.

In the example shown, the centrifugal fan12of the hot-air generator6is preferably at least partly housed/recessed into the lower supporting basement16of casing2, i.e. into the rear wall2bof the boxlike casing2, roughly at the end of the central/intermediate section of the air recirculating conduit11, and the outer volute or impeller housing of the centrifugal fan12is shaped/structured so as to directly communicate with, i.e. be fluidly connected to, both the central/intermediate section of the air recirculating conduit11and with the air-vent9integrated in the rear wall2bof casing2.

With reference toFIGS. 3,4,5and6, the air-filtering cartridge15in turn comprises:a first substantially bag- or pocket-shaped, air-filtering shell or vessel20which is dimensioned for being inserted/plugged in manually extractable manner into the air-vent10which is preferably realized on the annular frame that delimits, on front wall2a, the laundry loading/unloading opening of casing2, so as to substantially fill up the whole clear section of the air-vent10, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls21which are structured to restrain the fluff and/or lint particles in suspension into the airflow f that enters into the air recirculating conduit11through the air-vent10; and preferably alsoa permeable-to-air, preferably substantially plate like-shaped, upper lid22which is rigidly associated/fixed to the bag-shaped, air-filtering shell or vessel20so as to close the upper mouth of the same bag-shaped, air-filtering shell or vessel20, and which is furthermore shaped/dimensioned so as to close/cover the whole air-vent10.

In the example shown, the air-filtering walls21of shell20are preferably, though not necessarily, substantially specularly inclined to the center-plane M of the air-filtering shell or vessel20, so that the air-filtering shell or vessel20has a substantially V- or U-shaped cross section.

The substantially bag- or pocket-shaped, air-filtering shell or vessel20is moreover divided into two complementary valve-like pieces23which are selectively separable to one another, and each valve-like piece23preferably incorporates a respective permeable-to-air sidewall21of the air-filtering shell or vessel20. Preferably the two valve-like pieces23are furthermore laterally hinged to one another approximately at the bottom of the air-filtering shell or vessel20, i.e. opposite to the upper mouth of the air-filtering shell or vessel20, for reciprocal rotation about a transversal reference axis A which is preferably substantially parallel to the permeable-to-air sidewalls21of the air-filtering shell or vessel20, so that the whole air-filtering shell or vessel20is openable in a book-like manner about reference axis A.

In the example shown, the two valve-like pieces23of the air-filtering shell or vessel20are preferably pivotally jointed to one another via a pair of connecting hinges24which are aligned to the reference axis A and are located approximately on the bottom of the air-filtering shell or vessel20, i.e. opposite to the upper mouth of the air-filtering shell or vessel20. Furthermore the articulation axis of the two connecting hinges24, i.e. the rotation axis A of the two valve-like pieces23, preferably substantially lies on the center-plane M of the air-filtering shell or vessel20, and further preferably, it extends transversally relative to the direction of the airflow f passing through the air-filtering cartridge15.

With reference toFIGS. 3,4,5and6, similarly to the air-filtering shell or vessel20, the permeable-to-air upper lid22of the air-filtering cartridge15is preferably divided into two permeable-to-air complementary pieces25which are preferably substantially plate-like shaped and selectively separable to one another, and each of which is permanently rigidly fixed to a respective valve-like piece23of the bag-shaped, air-filtering shell or vessel20, so as to allow the bag-shaped, air-filtering shell or vessel20to open in a book-like manner.

Preferably, the two pieces25of the upper lid22furthermore incorporate a manually-operable snap-on locking mechanism26which is structured for selectively rigidly anchoring the two pieces25to one another when they are reciprocally coupled to form/compose the permeable-to-air upper lid22, thus preventing any unintended opening of the first air-filtering shell or vessel20.

In the example shown, each permeable-to-air, preferably substantially plate-like-shaped piece25of the upper lid22is preferably realized in one piece with a respective valve-like piece23of the bag-shaped, air-filtering shell or vessel20. As an alternative, the permeable-to-air upper lid22of the air-filtering cartridge15may be permanently rigidly associated/fixed to one of the two valve-like pieces23of the air-filtering shell or vessel20, and be structured for selectively couple in a rigid and stable, though easily releasable manner to the edge of the other valve-like piece23of the air-filtering shell or vessel20.

With reference toFIGS. 3,4,5and6, the air-filtering cartridge15furthermore comprises a second substantially bag- or pocket-shaped, air-filtering shell or vessel30which is fitted/recessed into the first substantially bag-shaped, air-filtering shell or vessel20, beneath the upper lid22, so as to be crossed by substantially the same airflow f that crosses the filtering shell20, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls31, each of which is structured to restrain the fluff and/or lint particles in suspension into the airflow f and is locally faced and superimposed to a respective permeable-to-air sidewall21of the air-filtering shell or vessel20. According to the invention, the airflow f, after having passed through the upper lid22, passes first through the second substantially bag- or pocket-shaped, air-filtering shell or vessel30and then through the first bag- or pocket-shaped, air-filtering shell or vessel20.

Preferably, though not necessarily, the permeable-to-air sidewalls31of the second air-filtering shell or vessel30are furthermore structured to restrain fluff and/or lint particles having smaller dimensions than that restrained by the permeable-to-air sidewalls21of the first air-filtering shell or vessel20.

Second air-filtering shell or vessel30is mechanically slidingly coupled to the first air-filtering shell or vessel20, so that the permeable-to-air sidewalls31of the second air-filtering shell or vessel30are able to slide sideways with respect to the corresponding permeable-to-air sidewalls21of the first air-filtering shell or vessel20.

In other words, the second air-filtering shell or vessel30is mechanically coupled to the first air-filtering shell or vessel20in sliding manner, so that each permeable-to-air sidewall31of the second air-filtering shell or vessel30is able to slide sideways with respect to the corresponding permeable-to-air sidewall21of the first air-filtering shell or vessel20, in a direction d which is substantially parallel to the same permeable-to-air sidewall21of the first air-filtering shell or vessel20.

With reference toFIGS. 3,4and5, in the example shown, the second air-filtering shell or vessel30is preferably shaped/structured so as to be manually extractable in drawer-like manner from the first air-filtering shell or vessel20, though a specific pass-through opening or slot27formed on a side of the same first air-filtering shell or vessel20.

Preferably, the pass-through opening or slot27is delimited by the peripheral borders of the two valve-like pieces23of the first air-filtering shell or vessel20.

The second air-filtering shell or vessel30is preferably shaped/structured so as to be manually extractable in drawer-like manner from the first air-filtering shell or vessel20, in a direction d which is substantially parallel to the rotation axis A of the two valve-like pieces23of the air-filtering shell or vessel20.

The second, substantially bag-shaped, air-filtering shell or vessel30, similarly to the first bag-shaped air-filtering shell or vessel20, is preferably divided into two complementary valve-like pieces32which are selectively separable to one another, and each of the two valve-like pieces32incorporates a respective permeable-to-air sidewall31of the air-filtering shell or vessel30. Furthermore the two valve-like pieces32of air-filtering shell or vessel30are preferably laterally hinged to one another so that the whole bag-shaped, air-filtering shell or vessel30is openable in a book-like manner.

With reference toFIG. 6, in the example shown, the two valve-like pieces32of the air-filtering shell or vessel30are pivotally jointed to one another via a pair of connecting hinges33which are located on a side edge of the air-filtering shell or vessel30. Furthermore, the reference axis of the two connecting hinges34, i.e. the rotation axis B of the two valve-like pieces32, is substantially perpendicular to the rotation axis A of the valve-like pieces23of the air-filtering shell or vessel20. If preferred, the pair of connecting hinges33and their rotational axis B may be arranged parallel to the rotation axis A of the valve-like pieces23of the air-filtering shell or vessel20.

Preferably, each valve-like piece32of the second air-filtering shell or vessel30is furthermore shaped/structured so to mechanically couple with a respective valve-like piece23of the first air-filtering shell or vessel20, so as to be able to slide with respect to the same respective valve-like piece23in a direction d which is both substantially parallel to the reference laying plane of the same valve-like piece23of the first air-filtering shell or vessel20, and also substantially parallel to the rotation axis A of the two valve-like pieces23of the air-filtering shell or vessel20.

With reference toFIGS. 4 and 6, each valve-like piece32of the second air-filtering shell or vessel30is preferably provided with at least one transversal drawer runner34which is shaped so as to engage in axially sliding manner a corresponding rectilinear groove34arealized on the corresponding valve-like piece23of the first air-filtering shell or vessel20. The rectilinear groove34aextends parallel to the rotation axis A of the two valve-like pieces23of the air-filtering shell or vessel20. Guiding surfaces34,34aare coupled in a sliding manner such that the second air-filtering shell or vessel30is slidably movable relative to the first air-filtering shell or vessel20between a first position wherein a permeable-to-air sidewall21of the first air-filtering shell or vessel20is facing and superimposed to a permeable-to-air sidewall31of the second air-filtering shell or vessel30, and a second position wherein the superimposition of the permeable-to-air sidewalls21,31of the first and second air-filtering shell or vessel20,30is removed. In the second position, the second air-filtering shell or vessel30is extracted from the first air-filtering shell or vessel20. In said first position a gap40separates the permeable-to-air sidewalls21of the first air-filtering shell or vessel20from the permeable-to-air sidewalls31of the second air-filtering shell or vessel30.

The second, substantially bag-shaped, air-filtering shell or vessel30is preferably also provided with a manually-operated, snap-on locking mechanism35which is structured for selectively rigidly anchoring the second air-filtering shell or vessel30to the first air-filtering shell or vessel20, so to prevent any unintended extraction of the second air-filtering shell or vessel30from the first air-filtering shell or vessel20. The snap-on locking mechanism35comprises one or more recesses35aformed in one or both valve-like piece32of the second air-filtering shell or vessel30and one or more protrusions35bcorrespondingly located on one or both valve-like piece23of the first air-filtering shell or vessel20. Each protrusion35bengages a corresponding recess35awhen the second air-filtering shell or vessel30is completely inserted into the first air-filtering shell or vessel20

With reference toFIGS. 7,8,9and10, according to an alternative embodiment, the air-filtering cartridge15comprises:a first substantially bag- or pocket-shaped, air-filtering shell or vessel120which is dimensioned for being inserted/plugged in manually extractable manner into the air-vent10preferably realized on the annular frame that delimits, on front wall2a, the laundry loading/unloading opening of casing2, so as to substantially fill up the whole clear section of the air-vent10, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls121which are structured to restrain the fluff and/or lint particles in suspension into the airflow f that enters into the air recirculating conduit11through the air-vent10;a second substantially bag- or pocket-shaped, air-filtering shell or vessel130which is fitted/recessed into the first substantially bag-shaped, air-filtering shell or vessel120, so as to be crossed by substantially the same airflow f that crosses the filtering shell120, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls131, each of which is structured to restrain the fluff and/or lint particles in suspension into the airflow f and is locally faced and superimposed to a respective permeable-to-air sidewall121of the air-filtering shell or vessel120

The air filtering cartridge further comprises a permeable-to-air upper lid122which is rigidly associated/fixed to the second, substantially bag-shaped, air-filtering shell or vessel130, so as to contemporaneously close the upper mouth of the second air-filtering shell or vessel130and the upper mouth of the first air-filtering shell or vessel120. According to the invention, the airflow f, after having passed through the upper lid122, passes first through the second substantially bag- or pocket-shaped, air-filtering shell or vessel130and then through the first bag- or pocket-shaped, air-filtering shell or vessel120.

Again the second air-filtering shell or vessel130is mechanically slidingly coupled to the first air-filtering shell or vessel120, so that the permeable-to-air sidewalls131of the second air-filtering shell or vessel130are able to slide sideways with respect to the corresponding permeable-to-air sidewalls121of the first air-filtering shell or vessel120.

The substantially bag-shaped, air-filtering shell or vessel120is divided into two complementary valve-like pieces123which are selectively separable to one another, and each of the two valve-like pieces123incorporates a respective permeable-to-air sidewall121of the air-filtering shell or vessel120. Furthermore the two valve-like pieces123of air-filtering shell or vessel120are preferably laterally hinged to one another so that the whole bag-shaped, air-filtering shell or vessel120is openable in a book-like manner.

Similarly to the air-filtering shell or vessel120, the second, substantially bag-shaped, air-filtering shell or vessel130is divided into two complementary valve-like pieces132which are selectively separable to one another, and each of which incorporates a respective permeable-to-air sidewall131of the air-filtering shell or vessel130.

Each of the two valve-like pieces132of the second air-filtering shell or vessel130is furthermore mechanically slidingly coupled to a respective valve-like piece123of the first air-filtering shell or vessel120, so as to be able to slide with respect to the valve-like piece123in a direction d′ which is both substantially parallel to the reference laying plane of the permeable-to-air sidewall121of the same valve-like piece123, and also substantially perpendicular to the permeable-to-air upper lid122, i.e. substantially perpendicular to the upper mouth of the first and second air-filtering shells or vessels120and130.

With reference toFIGS. 9 and 10, each valve-like piece132of the second air-filtering shell or vessel130is preferably permanently mechanically slidingly coupled by means of guiding surfaces134,134ato a respective valve-like piece123of the first air-filtering shell or vessel120, so as to be able to slide with respect to the valve-like piece123between a first operating position (seeFIGS. 7,8and9) in which the permeable-to-air sidewall131of the valve-like piece132is superimposed to the permeable-to-air sidewall121of the corresponding valve-like piece123; and a second operating position (seeFIG. 10) in which the permeable-to-air sidewall131of the valve-like piece132is arranged beside the permeable-to-air sidewall121of the corresponding valve-like piece123. In said first position the permeable-to-air sidewalls121of the first air-filtering shell or vessel120mates the permeable-to-air sidewalls131of the second air-filtering shell or vessel130, so as to be locally parallel thereto and preferably substantially adherent thereto. In said second position the superimposition between the permeable-to-air sidewalls121,131of the first and second air-filtering shell or vessel120,130is removed.

With reference toFIGS. 7 to 10, in the example shown, the two valve-like pieces123of the first air-filtering shell or vessel120are pivotally jointed to one another by means of a pair of connecting hinges124located approximately on the bottom of the air-filtering shell or vessel120, i.e. opposite to the upper lid122. Furthermore the reference axis of the two connecting hinges124, i.e. the rotation axis A′ of the two valve-like pieces123, preferably substantially lies on the center-plane N of the air-filtering shell or vessel120.

The second, substantially bag-shaped, air-filtering shell or vessel130, in turn, is divided into two complementary valve-like pieces132each of which is mechanically slidingly coupled by means of guiding surfaces134,134ato a respective valve-like piece123of the first air-filtering shell or vessel120, so as to be able to slide with respect to the valve-like piece123in a direction d′ which is substantially perpendicular to the rotation axis A′ of the two valve-like pieces123of the air-filtering shell or vessel120. Guiding surfaces134,134aare formed, respectively, on each valve-like piece132of the second air-filtering shell or vessel130and on each valve-like piece123of the first air-filtering shell or vessel120.

With reference toFIGS. 7 and 8, in the example shown, the air-filtering walls121of the first air-filtering shell or vessel120and the air-filtering walls131of second air-filtering shell or vessel130are preferably substantially specularly inclined to the center-plane N of the air-filtering shell or vessel120, so that the both air-filtering shells or vessels120and130has a substantially V- or U-shaped cross section.

Preferably, though not necessarily, the permeable-to-air sidewalls131of the second air-filtering shell or vessel130are furthermore structured to restrain fluff and/or lint particles having smaller dimensions than that restrained by the permeable-to-air sidewalls121of the first air-filtering shell or vessel120.

With reference toFIGS. 7 to 10, similarly to the air-filtering shells or vessels120and130, the permeable-to-air upper lid122of the air-filtering cartridge15is preferably divided into two permeable-to-air, preferably substantially plate-like-shaped, complementary pieces125which are selectively separable to one another, and each of which is permanently rigidly fixed to a respective valve-like piece132of the second air-filtering shell or vessel130, so as to allow the two substantially bag-shaped, air-filtering shells or vessels120and130to open in a book-like manner.

Preferably, the two pieces125of the upper lid122furthermore incorporate a manually-operable snap-on locking mechanism126which is structured for selectively rigidly anchoring the two pieces125to one another when they are reciprocally coupled to form/compose the permeable-to-air upper lid122, thus preventing any unintended opening of both air-filtering shells or vessels120and130.

In the example shown, each permeable-to-air piece125of the upper lid122is preferably realized in one piece with a respective valve-like piece132of the second air-filtering shell or vessel130.

As an alternative, the permeable-to-air upper lid122of the air-filtering cartridge15may be permanently rigidly associated/fixed to one of the two valve-like pieces132of the second air-filtering shell or vessel130, and be structured for selectively coupling in a rigid and stable, though easily releasable manner to the edge of the other valve-like piece132of the air-filtering shell or vessel130.

With reference toFIGS. 11 and 12, a third embodiment, according to an alternative embodiment, the air-filtering cartridge15comprises:a first substantially bag- or pocket-shaped, air-filtering shell or vessel220which is dimensioned for being inserted/plugged in manually extractable manner into the air-vent10preferably realized on the annular frame that delimits, on front wall2a, the laundry loading/unloading opening of casing2, so as to substantially fill up the whole clear section of the air-vent10, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls221which are structured to restrain the fluff and/or lint particles in suspension into the airflow f that enters into the air recirculating conduit11through the air-vent10;a second substantially bag- or pocket-shaped, air-filtering shell or vessel230which is fitted/recessed into the first substantially bag-shaped, air-filtering shell or vessel220, so as to be crossed by substantially the same airflow f that crosses the filtering shell220, and which is provided with two preferably substantially flat, reciprocally-faced, permeable-to-air sidewalls231, each of which is structured to restrain the fluff and/or lint particles in suspension into the airflow f and is locally faced and superimposed to a respective permeable-to-air sidewall221of the air-filtering shell or vessel220

The air filtering cartridge further comprises a permeable-to-air upper lid222which is rigidly associated/fixed to the first, substantially bag-shaped, air-filtering shell or vessel220, so as to contemporaneously close the upper mouth of the first air-filtering shell or vessel220and the upper mouth of the second air-filtering shell or vessel230. According to the invention, the airflow f, after having passed through the upper lid222, passes first through the second substantially bag- or pocket-shaped, air-filtering shell or vessel230and then through the first bag- or pocket-shaped, air-filtering shell or vessel220.

The first air-filtering shell or vessel220is mechanically slidingly coupled to the second air-filtering shell or vessel230, so that the permeable-to-air sidewalls221of the first air-filtering shell or vessel220are able to slide sideways with respect to the corresponding permeable-to-air sidewalls231of the second air-filtering shell or vessel230.

The second substantially bag-shaped, air-filtering shell or vessel230is divided into two complementary valve-like pieces232which are selectively separable to one another, and each of the two valve-like pieces232incorporates a respective permeable-to-air sidewall231of the air-filtering shell or vessel230. Furthermore the two valve-like pieces232of air-filtering shell or vessel230are preferably laterally hinged to one another so that the whole bag-shaped, air-filtering shell or vessel230is openable in a book-like manner.

Similarly to the air-filtering shell or vessel230, the first substantially bag-shaped, air-filtering shell or vessel220is divided into two complementary valve-like pieces223which are selectively separable to one another, and each of which incorporates a respective permeable-to-air sidewall221of the air-filtering shell or vessel230.

Each of the two valve-like pieces223of the first air-filtering shell or vessel220is furthermore mechanically slidingly coupled to a respective valve-like piece232of the second air-filtering shell or vessel230, so as to be able to slide with respect to the valve-like piece232in a direction d′ which is both substantially parallel to the reference laying plane of the permeable-to-air sidewall231of the same valve-like piece232, and also substantially perpendicular to the permeable-to-air upper lid222, i.e. substantially perpendicular to the upper mouth of the first and second air-filtering shells or vessels220and230.

With reference toFIGS. 11 and 12, each valve-like piece223of the first air-filtering shell or vessel220is preferably permanently mechanically slidingly coupled by means of guiding surfaces234,234ato a respective valve-like piece232of the second air-filtering shell or vessel230, so as to be able to slide with respect to the valve-like piece232between a first operating position (seeFIG. 11) in which the permeable-to-air sidewall221of the valve-like piece223is superimposed to the permeable-to-air sidewall231of the corresponding valve-like piece232; and a second operating position (seeFIG. 12) in which the permeable-to-air sidewall221of the valve-like piece223is arranged beside the permeable-to-air sidewall231of the corresponding valve-like piece232. In said first position the permeable-to-air sidewalls221of the first air-filtering shell or vessel230mates the permeable-to-air sidewalls231of the second air-filtering shell or vessel230, so as to be locally parallel thereto and preferably substantially adherent thereto. In said second position the superimposition between the permeable-to-air sidewalls221,231of the first and second air-filtering shell or vessel220,230is removed.

With reference toFIGS. 11 and 12, in the example shown, the two valve-like pieces232of the second air-filtering shell or vessel230are pivotally jointed to one another by means of a pair of connecting hinges224located approximately on the bottom of the air-filtering shell or vessel230, i.e. opposite to the upper lid222. Furthermore the reference axis of the two connecting hinges224, i.e. the rotation axis A′ of the two valve-like pieces232, preferably substantially lies on the center-plane of the air-filtering shell or vessel220as viewed in a cross section view like that ofFIG. 8.

The first, substantially bag-shaped, air-filtering shell or vessel220, in turn, is divided into two complementary valve-like pieces223each of which is mechanically slidingly coupled by means of guiding surfaces234,234ato a respective valve-like piece232of the second air-filtering shell or vessel230, so as to be able to slide with respect to the valve-like piece232in a direction d′ which is substantially perpendicular to the rotation axis A′ of the two valve-like pieces232of the air-filtering shell or vessel230. Guiding surfaces234,234aare formed, respectively, on each valve-like piece232of the second air-filtering shell or vessel230and on each valve-like piece223of the first air-filtering shell or vessel220.

With reference toFIGS. 11 and 12, in the example shown, the air-filtering walls221of the first air-filtering shell or vessel220and the air-filtering walls231of second air-filtering shell or vessel230are preferably substantially specularly inclined to the center-plane of the air-filtering shell or vessel220as viewed in a cross section view like that ofFIG. 8, so that the both air-filtering shells or vessels220and230has a substantially V- or U-shaped cross section.

Preferably, though not necessarily, the permeable-to-air sidewalls231of the second air-filtering shell or vessel230are furthermore structured to restrain fluff and/or lint particles having smaller dimensions than that restrained by the permeable-to-air sidewalls221of the first air-filtering shell or vessel220.

With reference toFIGS. 11 and 12, similarly to the air-filtering shells or vessels220and230, the permeable-to-air upper lid222of the air-filtering cartridge15is preferably divided into two permeable-to-air, preferably substantially plate-like-shaped, complementary pieces225which are selectively separable to one another, and each of which is permanently rigidly fixed to a respective valve-like piece223of the first air-filtering shell or vessel220, so as to allow the two substantially bag-shaped, air-filtering shells or vessels220and230to open in a book-like manner.

Preferably, the two pieces225of the upper lid222furthermore incorporate a manually-operable snap-on locking mechanism226which is structured for selectively rigidly anchoring the two pieces225to one another when they are reciprocally coupled to form/compose the permeable-to-air upper lid222, thus preventing any unintended opening of both air-filtering shells or vessels220and230.

In the example shown, each permeable-to-air piece225of the upper lid222is preferably realized in one piece with a respective valve-like piece223of the first air-filtering shell or vessel220.

In the inner face side of one valve-like piece232of the second air-filtering shell or vessel230, a spacer241may be provided to keep valve-like pieces232spaced one another at a predetermined distance when the second air-filtering shell or vessel230is in a closed position, i.e. the two valve-like pieces232are coupled. The spacer241allows the valve-like pieces232to be pressed against the valve-like pieces223of the first air-filtering shell or vessel220to eliminate or reduce the possibility that the airflow f can flow between the first and second air-filtering shells or vessels220,230rather than through the second air-filtering shell or vessel230first.

General operation of the rotary-drum household laundry drier1is clearly inferable from the above description, with no further explanation required.

The advantages connected to the particular structure of the substantially air-filtering cartridge15are large in number.

In the air-filtering cartridge15, in fact, the fluff and/or lint particles tends to accumulate/settle on the inner face of the air-filtering walls21,31;121,131,221,231of both air-filtering shells or vessels20,120,220and30,130,230thus the fluff and/or lint particles remains inside the air-filtering shells or vessels20,120,220and30,130,220when the user disassembles/opens the air-filtering cartridge15for periodical cleaning.

Clearly, changes may be made to the rotary-drum household laundry drier1as described herein without, however, departing from the scope of the present invention.

For example, the air-cooling device13of hot-air generator6may comprise an air/air heat exchanger which is located inside the air recirculating conduit11, preferably upstream of the centrifugal fan12, and is structured for using the external fresh air to cool down the airflow f arriving from rotatable drum3; whereas the air-heating device14of hot-air generator6may consists in a resistor which is located inside the air recirculating conduit11, downstream of the air/air heat exchanger and preferably also downstream of centrifugal fan12.