EP2843113A1

EP2843113A1 - Rotary-drum laundry dryer

Info

Publication number: EP2843113A1
Application number: EP13181819.7A
Authority: EP
Inventors: Marco Costantin; Diego Dal Ben
Original assignee: Electrolux Appliances AB
Current assignee: Electrolux Appliances AB
Priority date: 2013-08-27
Filing date: 2013-08-27
Publication date: 2015-03-04

Abstract

The present invention in fact relates to a rotary-drum aundry dryer (1) comprising an outer casing (2) having a front wall (2a) and a rear wall (2b), a rotatable drum (3) which is structured for housing the laundry to be dried and is fixed in axially rotating manner inside the casing (2), the drum (3) being accessible by a user through a laundry loading/unloading opening (4a) closable by a door (4), and a hot-air generator (6) structured to circulate a stream of hot air through the rotatable drum (3). Furthermore, the rotatable drum comprises a substantially cylindrical, tubular body (3) which abuts against the front wall (2a) of the outer casing (2) so as to surround the laundry loading/unloading opening (4a) and is coupled in axially rotating manner to said front wall (2a) with the interposition of a front sealing gasket (11) between the tubular body (3) and the front wall (2a) of the outer casing (2), and which abuts against the rear wall (2b) of the outer casing (2) and is coupled in axially rotating manner to said rear wall (2b) with the interposition of a rear sealing gasket (12) between the tubular body (3) and the rear wall (2b) of the outer casing (2), each of said front sealing gasket (11) and/or rear sealing gasket (12) being housed in a corresponding front gasket groove or seat (5) and/or rear gasket groove or seat (16b). The rotary-drum laundry dryer of the present invention is characterised in that it further comprises at least a space compensating element (7a,7b) disposed in at least a portion of said front gasket groove or seat (5) and/or in at least a portion of said rear gasket groove or seat (16b).

Description

The present invention relates to a rotary-drum laundry dryer.
In particular, the present invention relates to a rotary-drum home laundry dryer to which the following description refers purely by way of example without implying any loss of generality.
As is known, rotary-drum home 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 is housed in axially rotating manner inside the casing to rotate about an horizontally-oriented longitudinal reference axis, 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; an open-circuit or 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 dry the laundry; and 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.
Furthermore, in most of the rotary-drum home laundry dryers currently on the market, the rotatable drum consists in a substantially cylindrical, rigid tubular body generally made of metal material and which extends substantially horizontally inside the boxlike casing, aligned to the laundry loading/unloading opening, and is structured for resting on a number of idle supporting rollers which are arranged at the two axial ends of the tubular body parallel to the drum longitudinal reference axis, and may be fixed to the appliance casing in free rotatable manner so as to allow the tubular body to rotate about its horizontally-oriented longitudinal reference axis. Typically, the circular front rim of the tubular body is coupled in airtight and axially rotating manner to the periphery of a funnel-shaped element which extends from the front wall of the appliance casing, towards the tubular body, and is shaped so as to converge to the laundry loading/unloading opening. On the rear side of the tubular body of the drum, in order to assure a tight rear closure thereof, the circular rear rim of the tubular body may be either coupled in axially rotating manner directly to the rear wall of the appliance casing or a circular gasket-supporting collar, having a nominal diameter greater than that of the rear rim of the tubular body, may be fixed to the periphery of a substantially circular, basin-shaped lid or cover fixed to the rear wall of the casing substantially coaxial to the tubular body.
More specifically, to avoid air leakages from the two axial ends of the tubular body, a front circular sealing gasket is generally interposed between the front rim of the tubular body and the periphery of the funnel-shaped element on the front wall of the casing, whereas a rear circular sealing gasket is generally interposed between the rear rim of the tubular body and the rear wall of the appliance casing.
In most of the rotary-drum home laundry dryers currently on market, the front circular sealing gasket is generally recessed into a circular groove or seat deep-drawn on the front wall of the appliance casing, whereas the rear circular sealing gasket is recessed into a circular groove deep-drawn on the rear wall of the appliance casing. Both circular sealing gaskets are firmly fixed to the bottom of the groove or seat so as to remain stationary when the rotatable drum rotates about its longitudinal reference axis, and the front and rear rims of the tubular body scrape in airtight manner against the corresponding front and rear circular sealing gasket.
However, there is the disadvantage that the rotary-drums diameter dimensions of the rotary-drum home laundry dryers currently on market may be different one each other for treating a maximum amount of laundry which is different for each dyer model; accordingly, it is necessary to adapt the dimensions of the front and rear sealing gaskets too in order to allow them to cooperate with such rotary-drums having different diameter dimensions. As a consequence of that, the dimensions of the corresponding seats housing the front and rear sealing gaskets are to be modified whenever the diameter of the rotary-drum changes. This involves high production costs and complex laundry dryer assembling procedure.
In addition, when it is necessary to replace a worn gasket with a new one to improve the performance of the rotary-drum home laundry dryer, there is the concrete possibility that the new gasket does not have the size exactly corresponding to that of the housing provided to accommodate the previous worn gasket. Thus, when the new gasket has smaller dimensions, especially dimensions of its transverse sectional shape, than the previous one, it could have problems of stability being received in a wider gasket seat.
Therefore, the aim of the present invention is to maintain the same shape and dimensions of the seats housing the front and rear sealing gaskets for a diameter dimension range of the rotary-drums, still maintaining good sealing properties of the front and rear gaskets housed in said seats.

SUMMARY OF THE INVENTION

In compliance with the above aims, according to the present invention there is provided a rotary-drum laundry dryer comprising an outer casing having a front wall and a rear wall, a rotatable drum which is structured for housing the laundry to be dried and is fixed in axially rotating manner inside the casing, the drum being accessible by a user through a laundry loading/unloading opening closable by a door, and a hot-air generator structured to circulate a stream of hot air through the rotatable drum.
Furthermore, the rotatable drum comprises a substantially cylindrical, tubular body which abuts against the front wall of the outer casing so as to surround the laundry loading/unloading opening and is coupled in axially rotating manner to said front wall with the interposition of a front sealing gasket between the tubular body and the front wall of the outer casing, and which abuts against the rear wall of the outer casing and is coupled in axially rotating manner to said rear wall with the interposition of a rear sealing gasket between the tubular body and the rear wall of the outer casing, each of said front sealing gasket and/or rear sealing gasket being housed in a corresponding front gasket groove or seat and/or rear gasket groove or seat.
The rotary-drum laundry dryer of the present invention is characterized in that it further comprises at least a space compensating element disposed in at least a portion of said front gasket groove or seat and/or in at least a portion of said rear gasket groove or seat.
By the present invention it is not necessary to re-structure the shape of the front and/or rear gasket groove or seat whenever a new sealing gasket replacing a worn one has smaller dimensions than such a worn sealing gasket. In particular, the presence of such a space compensating element disposed in a portion of said front gasket groove or seat and/or of said rear gasket groove or seat allows to continue to use the same sealing gasket groove or seat even if the new sealing gasket is smaller than the seat provided for receiving it. In fact, in such a case, a new sealing gasket may be inserted into the front and/or rear sealing gasket groove or seat in cooperation with the space compensating element which fills the empty space left in the front and/or rear sealing gasket groove or seat by the new sealing gasket. By this way, by the presence of said space compensating element, the air sealing in the rotary-drum laundry dryer of the present invention is assured also when it is used a sealing gasket having a transverse sectional shape smaller than the gasket groove or seat. In addition, the front and/or rear sealing gasket groove or seat is allowed to fit with drums of a rotary-drum laundry dryer having a wide range of diameters. Thus, it is possible to use rotary drums with reduced or enlarged diameters and to use gaskets of different dimensions keeping the gasket seats unchanged, with the further advantage of a reduced wear of the gasket seal.
In one embodiment, said at least a space compensating element is radially interposed between said front sealing gasket groove or seat and the front sealing gasket and/or between said rear sealing gasket groove or seat and the rear sealing gasket.
In another embodiment, said at least a space compensating element is interposed between said front sealing gasket groove or seat and the front sealing gasket and/or between said rear sealing gasket groove or seat and the rear sealing gasket along a direction parallel to the drum rotational direction.
Furthermore and preferably, though not necessarily, said front sealing gasket groove or seat and/or said rear sealing gasket groove or seat is wider than the relative front sealing gasket and/or rear sealing gasket and each size difference between the sealing gasket groove or seat and the relative gasket is compensated by said space compensating element.
Furthermore and preferably, though not necessarily, said front sealing gasket and/or rear sealing gasket is hold in its corresponding front or rear sealing gasket groove or seat by interposition of said at least a space compensating element.
Furthermore and preferably, though not necessarily, said at least a space compensating element is substantially ring-shaped.
Furthermore and preferably, though not necessarily, said tubular body of the drum comprises a front rim coupled in airtight and axially rotating manner to a front bulkhead associated to the front wall, so as to surround the laundry loading/unloading opening.
Furthermore and preferably, though not necessarily, said front sealing gasket is interposed between said front rim of the tubular body and the front bulkhead.
Furthermore and preferably, though not necessarily, said front rim is coupled in airtight and axially rotating manner to the periphery of a substantially funnel-shaped element which extends from said front wall of the casing towards the tubular body, and is shaped so as to converge to the laundry loading/unloading opening.
In a first embodiment, said substantially cylindrical tubular body of the rotatable drum has a back wall rigidly connected thereto, the tubular body being arranged so that said back wall is coupled in substantially airtight and axially rotating manner to the rear wall of the casing with the interposition of said rear sealing gasket.
Furthermore and preferably, though not necessarily, in said a first embodiment said rear wall of the outer casing comprises: a substantially vertically-oriented supporting bulkhead having a central portion which is substantially aligned/faced to a permeable-to-air inner portion of the back wall of the rotatable drum; and a gasket-supporting member which is fixed/attached to the inner face of the supporting bulkhead so to be interposed between the central portion of said supporting bulkhead and the back wall of the tubular body, and which has a central pass-through opening substantially aligned/faced to the permeable-to-air inner portion of said back wall and fluidly connected to the hot-air generator.
Furthermore and preferably, though not necessarily, said supporting bulkhead is fluidly connected to the hot-air generator and said gasket-supporting member is provided with said rear gasket groove or seat which is faced to the back wall of the tubular body, encircles the central pass-through opening of the gasket-supporting member and is shaped/ dimensioned so to house the rear sealing gasket and keep said rear sealing gasket in abutment against the back wall of the tubular body. Furthermore and preferably, though not necessarily, said gasket-supporting member is substantially ring-shaped.
Furthermore and preferably, though not necessarily, in said first embodiment said supporting bulkhead is centrally provided with a substantially sink-shaped bulge which is substantially aligned/faced to the permeable-to-air inner portion of the back wall of said tubular body, protrudes outwards of the outer casing and is fluidly connected to the hot-air generator.
Furthermore and preferably, though not necessarily, in said first embodiment said ring-shaped gasket-supporting member is shaped/dimensioned so to completely cover and/or surround the peripheral border of the sink-shaped bulge.
Furthermore and preferably, though not necessarily, in said first embodiment said rear gasket groove or seat is substantially circular in shape and is dimensioned so to house the rear sealing gasket and a space compensating element and keep said rear sealing gasket in abutment against the back wall of the rotatable drum all around the permeable-to-air inner portion of said back wall. Furthermore and preferably, though not necessarily, said permeable-to-air inner portion of the back wall of the tubular body is substantially circular in shape and is located approximately at centre of said back wall.
Furthermore and preferably, though not necessarily, in said first embodiment said rear wall of the outer casing furthermore comprises an outer lid or cover which is rigidly attached to the outer face of the supporting bulkhead, and is suitably shaped/structured to fluidly connected the sink-shaped bulge of the supporting bulkhead to the hot-air generator, so as to channel the stream of hot air produced by the hot-air generator towards the sink-shaped bulge, or vice versa.
In a second embodiment, a substantially circular, the rotary-drum laundry dryer further comprises a substantially circular, basin-shaped lid or cover is fixed to the rear wall of the casing substantially coaxial to the tubular body, so as to form, on said rear wall, a cavity which communicates with the hot-air generator, and in addition comprises a circular gasket-supporting collar which has a nominal diameter greater than that of the rear rim of the tubular body, and is fixed to the periphery of the basin-shaped lid or cover and/or to the rear wall of the casing, coaxial to the tubular body, the rear circular sealing gasket being force fitted into the gasket-supporting collar so as to come in abutment against the periphery of the basin-shaped lid or cover around the perimeter of the latter.
Furthermore and preferably, though not necessarily, in said second embodiment, the rear wall of the casing is provided with a substantially sink-shaped bulge or recess which projects outwards the casing, is located inside the perimeter of the rear sealing gasket, and communicates with the hot-air generator; the basin-shaped lid or cover being fixed to the rear wall of the casing substantially coaxial to the tubular body, so as to close the outwards-projecting bulge or recess made on the rear wall of the casing.
Furthermore and preferably, though not necessarily, the basin-shaped lid or cover is firmly fixed to the rear wall of the casing in substantially airtight manner.
Furthermore and preferably, though not necessarily, in said second embodiment, a circular sealing gasket is interposed between the basin-shaped lid or cover and the rear wall of the casing.
Furthermore and preferably, though not necessarily, in said second embodiment, at least a portion of the basin-shaped lid or cover is properly perforated, or at any rate permeable to air, to permit hot air to flow into revolving drum or vice versa.
Furthermore and preferably, though not necessarily, in said second embodiment, the sink-shaped bulge or recess on the rear wall of the casing is substantially circular in shape, and is substantially coaxial to the tubular body; and the basin-shaped lid or cover is fixed to the rear wall of the casing with its concavity directly facing the bottom of the outwards-projecting bulge or recess on the rear wall of the casing, so as to form, on said rear wall, a substantially lenticular-shaped cavity. Furthermore and preferably, though not necessarily, the central section of the bottom of the basin-shaped lid or cover is provided with a substantially cup-shaped contra-oriented bulge or recess which projects towards the bottom of the outwards-projecting bulge or recess on the rear wall of the casing. Furthermore and preferably, though not necessarily, the periphery of the basin-shaped lid or cover is fixed to the rear wall of the casing via seam-folding and/or clinching and/or riveting and/or spot-welding or similar.
Furthermore and preferably, though not necessarily, in said second embodiment, the circular gasket-supporting collar is fixed to the periphery of the basin-shaped lid or cover and/or to the rear wall of the casing via seam-folding and/or clinching and/or riveting and/or spot-welding or similar. Furthermore and preferably, though not necessarily, the circular gasket-supporting collar is made in one piece with the basin-shaped lid or cover.
Furthermore and preferably, though not necessarily, the rear sealing gasket consists of a monolithic, toroidal-shaped ring made of rubber or other elastomeric polymer suitable to be force fitted into the circular gasket-supporting collar. Furthermore and preferably, though not necessarily, said toroidal-shaped ring has a hollow structure.
Furthermore and preferably, though not necessarily, the basin-shaped lid or cover and/or the circular gasket-supporting collar are made of metal material.
Furthermore and preferably, though not necessarily, the tubular body rests substantially horizontally inside the casing on a number of substantially horizontally-oriented supporting rollers which are located close to both axial ends of the tubular body, and are associated to the casing in free revolving manner so as to allow the tubular body to freely rotate inside the casing about its horizontally-oriented longitudinal axis.
Furthermore and preferably, though not necessarily, the hot-air generator is a closed-circuit, hot-air generator which is structured for gradually drawing air from revolving drum; extracting and retaining the surplus moisture from the hot air drawn from revolving drum; heating the dehumidified air to a predetermined temperature, normally higher than the temperature of the air arriving from revolving drum; and feeding the heated, dehumidified air back into revolving drum, where it flows over, to rapidly dry, the laundry inside the drum.
Furthermore and preferably, though not necessarily, the rotary-drum laundry dryer also comprises, inside the casing, a motor assembly which is structured to drive into rotation, on command, the tubular body about its longitudinal axis.
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 is a perspective view, with parts removed for clarity, of a first embodiment of rotary-drum laundry dryer made in accordance with the teachings of the present invention;
Figure 2 is a section view with parts enlarged of the Figure 1 laundry dryer with parts removed for clarity;
Figure 3 is an enlarged view of a portion of the rear wall of the Figure 2 laundry dryer with parts removed for clarity;
Figure 4 is a partly-exploded perspective view of the rear wall of the Figures 1 and 2 laundry dryer with parts removed for clarity;
Figure 5 shows an enlargement of the front portion of the drum of the rotary-drum laundry dryer of Figure 1;
Figure 6 is a front view with parts removed for clarity of a second embodiment of rotary-drum laundry dryer made in accordance with the teachings of the present invention;
Figure 7 is a partly-exploded perspective view of the rotary-drum laundry dryer of Figure 6;
Figure 8 is a section view with parts enlarged of the Figure 6 laundry dryer with parts removed for clarity.

With reference to Figures 1 and 2, reference number 1 indicates as a whole a rotary-drum home laundry dryer according to a first embodiment of the present invention which comprises: a preferably, though not necessarily, parallelepiped-shaped, outer boxlike casing 2 which is structured for resting on the floor and is provided with reciprocally-faced, substantially vertically-oriented, front and rear walls 2a and 2b; a substantially cylindrical rotatable drum 3 structured for housing the laundry to be dried, and which is fixed in axially rotating manner inside the boxlike casing 2, facing a laundry loading/unloading pass-through opening 4a formed on the front wall 2a of casing 2; and a porthole door 4 hinged to the front wall 2a of casing 2 so 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 door 4 rests completely against the front wall 2a to close the laundry loading/unloading opening 4a and substantially airtight seal the rotatable drum 3.
Inside the boxlike casing 2, the laundry dryer 1 additionally comprises an electrically-powered motor assembly (not shown) structured for driving into rotation the rotatable drum 3 about its longitudinal reference axis; an open-circuit or closed-circuit, hot-air generator 6 which is structured to circulate through the rotatable drum 3 a stream of hot air having a low moisture level, and which flows over and dries the laundry located inside the drum 3; and an electronic central control unit (not shown) which controls both the motor assembly and the hot-air generator 6 to perform, on command, one of the user-selectable drying cycles preferably, though not necessarily, stored in the same central control unit.
With reference to Figures 2 to 4, the rotatable drum 3 consists in a substantially cylindrical, tubular body 3 which is preferably made of metal material and is arranged inside the boxlike casing 2 coaxial to a preferably substantially horizontally-oriented, longitudinal reference axis L, so that the circular front rim 3f of the tubular body 3 is faced/aligned to the laundry loading/unloading opening 4a realized on the front wall 2a of the boxlike casing 2, and so that the back of the tubular body 3 is faced to the rear wall 2b of the same boxlike casing 2. The back of the tubular body 3 is furthermore shaped/structured so to be at least partly permeable to air, so that the stream of hot air arriving from the hot-air generator 6 is allowed to flow through the back/bottom of the bell-shaped body 3.
In other words, the tubular body 3 comprises a substantially cylindrical lateral wall 8 which extends inside the boxlike casing 2 coaxial to a preferably substantially horizontally-oriented, longitudinal reference axis L which is aligned to the laundry loading/unloading opening realized on front wall 2a, so that circular front rim of the same substantially cylindrical lateral wall 8, i.e. the front rim 3f of the tubular body 3, abuts against the front wall 2a of casing 2 and surrounds the laundry loading/unloading opening 4a of the same front wall 2a; and a preferably, though not necessarily, dish-shaped, back wall 9 which is faced to the rear wall 2b of the boxlike casing 2, and is permanently rigidly coupled to the circular rear rim 3b of the substantially cylindrical lateral wall 8 so as to close said rear rim 3b and form, together with lateral wall 8, a substantially cylindrical, cup-shaped rigid container 3 structured for housing the laundry to be dried.
An inner portion 9c of the preferably substantially dish-shaped back wall 9 is furthermore suitably perforated, or at any rate structured to be permeable to air, so as to allow the stream of hot air arriving from the hot-air generator 6 to flow through the back wall 9 of the tubular body 3. The permeable-to-air inner portion 9c of back wall 9 is preferably located approximately at centre of the preferably dish-shaped back wall 9 so as to be substantially coaxial to the longitudinal reference axis L of the rotatable drum 3, and is preferably substantially circular in shape.
With reference to Figures 2 to 4, in the example shown, the substantially cylindrical lateral wall 8 of tubular body 3 is preferably structured for resting on a number of idle supporting rollers 10 which are arranged approximately at the two axial ends of the tubular body 3 with their rotation axis substantially parallel to the drum longitudinal reference axis L, so as to allow the tubular body 3 to rotate about the longitudinal reference axis L inside the boxlike casing 2. The idle supporting rollers 10 may be preferably fixed to the boxlike casing 2 in rotatable manner.
Furthermore, the preferably dish-shaped back wall 9 of the tubular body 3 substantially abuts against the rear wall 2b of the boxlike casing 2 and is coupled in substantially airtight and axially rotating manner to said rear wall 2b with the interposition of a rear circular sealing gasket 12. Rear circular sealing gasket 12 is substantially coaxial to the drum longitudinal reference axis L. The rear circular sealing gasket 12 is firmly fixed to the rear wall 2b of the boxlike casing 2.
With reference to Figures 2 to 4, the rear wall 2b of boxlike casing 2 comprises a substantially vertically-oriented, supporting panel or bulkhead 14 which is preferably, though not necessarily, made of metal material and is preferably centrally provided with a substantially sink-shaped bulge 15 which is substantially aligned/faced to the permeable-to-air inner portion 9c of the preferably dish-shaped back wall 9 of tubular body 3, projects/protrudes outwards of the boxlike casing 2 and is in communication with, i.e. is fluidly connected to, the hot-air generator 6 so as to receive the stream of hot air produced by the hot-air generator 6.
In other words, the permeable-to-air inner portion 9c of back wall 9 of tubular body 3 is located/arranged within the perimeter of the sink-shaped bulge 15 on supporting bulkhead 14.
In the example shown, the sink-shaped bulge 15 is preferably substantially circular in shape and protrudes outwards of the boxlike casing 2 while remaining substantially coaxial to the drum longitudinal reference axis L, i.e. while remaining substantially coaxial to the back wall 9 of the tubular body 3. The sink-shaped bulge 15 furthermore has a peripheral diameter lower than the nominal diameter of the substantially cylindrical lateral wall 8 of the tubular body 3 and/or the outer diameter of back wall 9, and preferably also greater than the peripheral diameter of the permeable-to-air inner portion 9c of back wall 9, so that the permeable-to-air inner portion 9c of back wall 9 is located/arranged approximately at centre of the sink-shaped bulge 15.
Lastly, the sink-shaped bulge 15 of supporting bulkhead 14 preferably communicates with the hot-air generator 6 via a pass-through opening 15a made on the bottom of the same sink-shaped bulge 15.
With reference to the embodiment shown in Figures 2 to 4, the rear wall 2b of boxlike casing 2 moreover comprises a substantially ring-shaped gasket-supporting member 16 which is fixed/attached to the inner face of the supporting bulkhead 14, above the sink-shaped bulge 15 of supporting bulkhead 14 and substantially coaxial to the back wall 9 of tubular body 3, i.e. substantially coaxial to the drum longitudinal reference axis L, so as to protrude from the inner face of the supporting bulkhead 14 and be interposed between the central portion of the supporting bulkhead 14 and the back wall 9 of tubular body 3. This ring-shaped gasket-supporting member 16 is furthermore suitably shaped/dimensioned so to cover and/or encircle the peripheral border of the sink-shaped bulge 15 on supporting bulkhead 14, and so that the preferably substantially circular-shaped, central pass-through opening 16a of the gasket-supporting member 16 is substantially faced/aligned to the permeable-to-air inner portion 9c of the back wall 9 of tubular body 3.
In other words, the gasket-supporting member 16 is attached to the inner face of the supporting bulkhead 14 so to surround and cover the peripheral border of the sink-shaped bulge 15 on supporting bulkhead 14, and so that the central pass-through opening 16a of the gasket-supporting member 16 is preferably arranged substantially coaxial to the drum longitudinal reference axis L, i.e. substantially coaxial to the back wall 9 of tubular body 3.
Preferably the diameter of the central pass-through opening 16a of the gasket-supporting member 16 is furthermore greater than the peripheral diameter of the permeable-to-air inner portion 9c of the back wall 9 of tubular body 3.
In the example shown, the back wall 9 of tubular body 3 is preferably, though not necessarily, shaped so as to partly protrude into the central pass-through opening 16a of the gasket-supporting member 16 for placing the permeable-to-air inner portion 9c of back wall 9 inside the sink-shaped bulge 15 of supporting bulkhead 14. The central pass-through opening 16a of gasket-supporting member 16 therefore surrounds the permeable-to-air inner portion 9c of back wall 9 and is fluidly connected to the hot-air generator.
With reference to Figures 2 to 4, the front side of the substantially ring-shaped gasket-supporting member 16 faced to the back wall 9 of tubular body 3 is furthermore provided with a circular-shaped, rear annular groove or seat 16b which is arranged substantially coaxial to the drum longitudinal reference axis L, i.e. substantially coaxial to the back wall 9 of tubular body 3, encircles the central pass-through opening 16a of the gasket-supporting member 16 and preferably also the permeable-to-air inner portion 9c of back wall 9, and it is suitably shaped/dimensioned so to permanently house the rear circular sealing gasket 12 and keep said rear sealing gasket 12 in abutment against the back wall 9 of tubular body 3. This circular-shaped, rear annular groove 16b preferably has a substantially U-shaped cross-section.
In other words, the gasket-supporting member 16 is provided with a circular-shaped, rear annular groove 16b which is faced to the back wall 9 of tubular body 3, is arranged substantially coaxial to the back wall 9 of tubular body 3, and is shaped/dimensioned so to encircle the central pass-through opening 16a of the gasket-supporting member 16 and so to house the rear circular sealing gasket 12 and keep said gasket in abutment against the back wall 9 of tubular body 3 preferably all around the permeable-to-air inner portion 9c.
Moreover, the circular-shaped, rear annular groove 16b is dimensioned so as to keep the rear circular sealing gasket 12 in abutment against the back wall 9 of tubular body 3 preferably on the annular sector between the circular rear rim 3b of the cylindrical lateral wall 8 and the permeable-to-air inner portion 9c of the back wall 9. However, the rear annular groove 16b may be dimensioned so as to keep the rear circular sealing gasket 12 in abutment against the edge region of the back wall 9, i.e. in the region where the back wall 9 is fixed to the cylindrical lateral wall 8 of the tubular body 3.
Furthermore, the circular-shaped, rear annular groove 16b of the gasket-supporting member 16 is preferably arranged substantially coaxial to the drum longitudinal reference axis L, and has a nominal diameter slightly greater than that of the central pass-through opening 16a of the gasket-supporting member 16, so as to encircle both the central pass-through opening 16a of gasket-supporting member 16 and the permeable-to-air inner portion 9c of back wall 9.
With particular reference to Figures 2 and 3, the rotary-drum laundry dryer of the present invention further comprises a space compensating element 7b disposed in a portion of the rear annular groove or seat 16b, the space compensating element 7b being radially interposed between the rear gasket groove or seat 16b and the relative rear sealing gasket 12. As shown in Figures 2 and 3, the rear gasket groove or seat 16b is wider than the relative rear sealing gasket 12 and the size difference between the rear gasket groove or seat 16b and the relative rear gasket 12 is compensated by such a space compensating element 7b. In other words, the rear sealing gasket 12 is hold in its corresponding rear gasket groove or seat 16b by the interposition of such a space compensating element 7b. Preferably, though not necessarily, such a space compensating element 7b is substantially ring-shaped.
By this way, the presence of such a space compensating element 7b disposed in a portion of the rear gasket groove or seat 16b allows accommodating a rear sealing gasket 12 having a transverse sectional shape that is smaller than the shape of the transverse sectional shape of the rear gasket groove or seat 16b. In other words, a new rear sealing gasket 12, smaller than a previous worn one, may be inserted into the same rear gasket groove or seat 16b of above in cooperation with the space compensating element 7b, which fills the empty space left in the rear gasket groove or seat 16b by the new rear sealing gasket 12. In this way, by the presence of such a space compensating element 7b, the air sealing in the rotary-drum laundry dryer 1 of the present invention is assured also when a smaller rear sealing gasket 12 is used. In addition, the rear gasket groove or seat 16b is allowed to fit with a tubular body 3 of the rotary-drum laundry dryer 1 having a wide range of diameters. Thus, it is possible to use rotary drums 3 with reduced or enlarged diameters and adapt to them the corresponding rear sealing gasket 12, with the further advantage of a reduced wear of the rear sealing gasket 12 itself.
In the example shown, the ring-shaped gasket-supporting member 16 is preferably, though not necessarily, made in plastic material, preferably via an injection molding process. Furthermore, in the example shown the ring-shaped gasket-supporting member 16 is preferably attached/fixed to the inner face of supporting bulkhead 14 in substantially airtight manner, preferably, though not necessarily, with the interposition of an annular sealing gasket 17 that completely surrounds the sink-shaped bulge 15 of supporting bulkhead 14.
In the example shown, the rear circular sealing gasket 12 is preferably fixed and/or glued and/or force-fitted into the circular-shaped, annular rear groove 16b of the gasket-supporting member 16.
With reference to Figures 2, 3 and 4, the rear wall 2b of boxlike casing 2 preferably comprises an outer lid or cover 18 which is attached to the outer face of supporting bulkhead 14 preferably in substantially airtight manner, and is suitably shaped/structured to fluidly connect the sink-shaped bulge 15 of the supporting bulkhead 14 to the hot-air generator 6, so as to channel the stream of hot air produced by hot-air generator 6 towards the sink-shaped bulge 15, or vice versa.
In other words, the outer lid or cover 18 is suitably shaped/structured to put the pass-through opening 15a on the bottom of the sink-shaped bulge 15 in fluid communication with the hot-air generator 6.
Alike the gasket-supporting member 16, in the example shown the outer lid or cover 18 is preferably, though not necessarily, made in plastic material, preferably via an injection molding process.
In addition to the above, with reference to Figure 2 and 5, the front rim 3f of the tubular body 3, i.e. the circular front rim 3f of the substantially cylindrical lateral wall 8, is furthermore coupled in substantially airtight and axially rotating manner to a front panel or bulkhead 13 with the interposition of a front circular sealing gasket 11. The front panel or bulkhead 13 is associated to the front wall 2a of boxlike casing 2.
In the example shown, the front circular sealing gasket 11 is stationary recessed into a front circular groove or seat 5 made on the front panel or bulkhead 13 which is preferably associated to the front wall 2a of casing 2, so as to surround the laundry loading/unloading opening 4a on the front wall 2a, and the front rim 3f of tubular body 3 abuts against said front circular sealing gasket 11.
Furthermore, the front bulkhead 13 preferably comprises a substantially funnel-shaped coupling element which surrounds the laundry loading/unloading opening 4a on the front wall 2a of casing 2 and is preferably shaped/structured so as to connect the laundry loading/unloading opening 4a on front wall 2a to the front rim 3f of tubular body 3, and the front circular sealing gasket 11 is preferably stationary recessed into a front circular groove or seat 5 made on the periphery of the funnel-shaped coupling element of front bulkhead 13.
Front circular sealing gasket 11 is substantially coaxial to the drum longitudinal reference axis L.
With particular reference to Figure 5, similarly to the rear portion of the drum 3 disclosed above, the rotary-drum laundry dryer of the present invention further comprises at least a space compensating element 7a disposed in a portion of the front annular gasket groove or seat 5, the space compensating element 7a being radially interposed between the front gasket groove or seat 5 and the relative front sealing gasket 11. Again, as in the case of rear gasket groove or seat 16b, also the front gasket groove or seat 5 is wider than the relative front sealing gasket 11 and the size difference between the front gasket groove or seat 5 and the relative front sealing gasket 11 is compensated by such a space compensating element 7a. Preferably, though not necessarily, such a space compensating element 7a is substantially ring-shaped.
The advantages due to the presence of such a space compensating element 7a a disposed in a portion of the front gasket groove or seat 5 are the same as disclosed above with reference to the presence of the similar space compensating element 7b disposed in a portion of the rear gasket groove or seat 16b.
With reference to Figures 1 to 4, in the example shown, the boxlike casing 2 preferably comprises a supporting basement or socle 19 which is structured for resting on the floor and also for housing at least part of the hot-air generator 6; and a substantially parallelepiped-shaped upper boxlike cabinet 20 which is rigidly fixed to the top of the supporting basement or socle 19 and is structured so as to house the rotatable drum 3, i.e. the tubular body 3.
The laundry loading/unloading opening of boxlike casing 2 is located on the front wall of the upper boxlike cabinet 20, and the porthole door 4 is hinged to the front wall of the same upper boxlike cabinet 20. The idle supporting rollers 10 that support in rotatable manner the tubular body 3 are instead preferably fixed to the top of the supporting basement or socle 19. Preferably the supporting bulkhead 14 rests on the supporting basement or socle 19 and extends vertically up to the top panel of the casing 2.
As regards the tubular body 3, the front rim 3f of the tubular body 3 surrounds the laundry loading/unloading opening 4a on the front wall 2a of the upper boxlike cabinet 20 and is coupled in substantially airtight and axially rotating manner to the same front wall 2a of the boxlike cabinet 20, preferably with the interposition of the front circular sealing gasket 11.
With reference to Figures 1, 2 and 3, the hot-air generator 6, in turn, preferably, though not necessarily, consists in a closed-circuit, hot-air generator 6 which is structured for gradually drawing air from rotatable drum 3; cooling down the air arriving from rotatable drum 3 so to extract the surplus moisture in the air drawn from rotatable drum 3; heating the dehumidified air to a predetermined temperature normally higher than the temperature of the air drawn out from rotatable drum 3; and feeding the heated, dehumidified air back into the rotatable drum 3, where it flows over, the laundry inside the drum to dry said laundry.
In other words, the hot-air generator 6 provides for continually dehumidifying and heating the air circulating inside rotatable drum 3 to dry the laundry located inside the drum 3, and preferably comprises:

an air recirculating conduit 22 having a first end in communication with, i.e. fluidly connected to, the sink-shaped bulge 15 formed on supporting bulkhead 14, and a second end in communication with, i.e. is fluidly connected to, the front mouth of the tubular body 3;
an electrically-powered centrifugal fan 23 or other type of air circulating pump, which is located along the air recirculating conduit 22 and is structured to produce an airflow f which flows in closed loop through the air recirculating conduit 22 and the rotatable drum 3;
an air cooling device 24 which is located along the air recirculating conduit 22 preferably, though not necessarily, upstream of the air centrifugal fan 23, and is structured to cool the moist air arriving from rotatable drum 3 so as to cause the condensation of the surplus moisture inside the airflow f; and
an air heating device 25 which is located along the air recirculating conduit 22, downstream of the air cooling device 24 and preferably also upstream of the air centrifugal fan 23, and which is structured for heating the dehumidified airflow f arriving from the air cooling device 24 and directed back to rotatable drum 3, so that the airflow f directed back into rotatable drum 3 is heated to a temperature preferably, though not necessarily, higher than or equal to that of the moist air flowing out of rotatable drum 3.

Furthermore, the first end of the air recirculating conduit 22 communicates with, i.e. is fluidly connected to, the sink-shaped bulge 15 of the supporting bulkhead 14 via the outer lid or cover 18 attached to the outer face of the supporting bulkhead 14. The second end of the air recirculating conduit 22, instead, communicates with, i.e. is fluidly connected to, the front mouth of the tubular body 3 via a pass-through opening made in the preferably funnel-shaped coupling element of front bulkhead 13 that delimits/surrounds the laundry loading/unloading opening on the front wall 2a of the upper boxlike cabinet 20, i.e. of boxlike casing 2.
Furthermore, a central/intermediate section of the air recirculating conduit 22 preferably extends in pass-through manner across the supporting basement or socle 19 of the boxlike casing 2, and the air cooling device 24 and air heating device 25 are preferably completely recessed/housed inside said central/intermediate section of the air recirculating conduit 22.
With reference to Figures 1 and 2, the centrifugal fan 23 of hot-air generator 6 is preferably located on the back of the supporting basement or socle 19, immediately beneath the sink-shaped bulge 15 of supporting bulkhead 14, and is structured so to communicate with, i.e. be fluidly connected to, the central/intermediate section of the air recirculating conduit 22, and the outer lid or cover 18 of rear wall 2b is shaped/structured to fluidly connect the centrifugal fan 23 to the sink-shaped bulge 15 of supporting bulkhead 14.
The centrifugal fan 23 therefore communicates with, i.e. is fluidly connected to, the central/intermediate section of the air recirculating conduit 22 and the outwards-projecting, sink-shaped bulge 15 of supporting bulkhead 14, is able to produce an airflow f which flows from the central/intermediate section of the air recirculating conduit 22 to the sink-shaped bulge 15 of supporting bulkhead 14, or vice versa.
In the example shown, the centrifugal fan 23 of hot-air generator 6 is preferably at least partly housed/recessed into the rear wall 2b of the boxlike casing 2, preferably beneath the sink-shaped bulge 15 of supporting bulkhead 14, and the outer lid or cover 18 of rear wall 2b is suitably shaped/structured to fluidly connect the centrifugal fan 23 to the sink-shaped bulge 15 of supporting bulkhead 14.
Furthermore, with reference to Figures 1 to 4, the centrifugal fan 23 of hot-air generator 6 is preferably at least partly housed/recessed into the back of the supporting basement or socle 19 of casing 2, roughly at the end-opening of the central/intermediate section of the air recirculating conduit 22, and preferably comprises: an outer volute or impeller housing 26 which communicates with the central/intermediate section of the air recirculating conduit 22, and with the pass-through opening 15a on the bottom of the sink-shaped bulge 15 of bulkhead 14 via the outer lid or cover 18; and a rotating impeller (not shown) which is housed in axially rotating manner inside the impeller housing 26 so to generate, when rotating about its reference axis, an airflow f that flows from the central/intermediate section of the air recirculating conduit 22 to the sink-shaped bulge 15 of supporting bulkhead 14, or vice versa.
Furthermore, in the example shown the impeller housing 26 of centrifugal fan 23 is preferably, though not necessarily, divided into a first portion 26a made in one piece with the supporting basement or socle 19 of casing 2, and into a complementary second portion 26b which consists into a separated, cap-shaped rigid cover 26b which is shaped/structured for being substantially airtight coupled to the first portion 26a of the impeller housing 26, so as to form/compose the complete outer volute of centrifugal fan 23.
With reference to Figure 2 to 4, the second portion 26b of the impeller housing 26 is preferably made in plastic material, preferably via an injection molding process. Furthermore the outer lid or cover 18 is preferably, though not necessarily, made in one piece with the second portion 26b of the impeller housing 26 so as to form a single component part.
As regards the air cooling device 24 and air heating device 25, in the example shown the hot-air generator 6 is preferably, though not necessarily, provided with a heat-pump assembly which is structured for continuously removing moisture from, and then heating, the air circulating inside the air recirculating conduit 22 and the rotatable drum 3.
This heat-pump assembly comprises a first and a second air/refrigerant heat exchangers both located inside the air recirculating conduit 22, preferably upstream of the centrifugal fan 23. The first air/refrigerant heat exchanger, traditionally referred to as the "evaporator" of the heat-pump circuit, is located inside the air recirculating conduit 22 preferably upstream of the centrifugal fan 23, and is structured to remove moisture from the airflow arriving from rotatable drum 3, thus forming the air cooling device 24 of hot-air generator 6. The second air/refrigerant heat exchanger, traditionally referred to as the "condenser" of the heat-pump circuit, is instead located inside the air recirculating conduit 22 downstream of the first air/refrigerant heat exchanger 24, and is structured to release heat to the airflow arriving from the first air/refrigerant heat exchanger 24, thus forming the air heating device 25 of hot-air generator 6.
General operation of the rotary-drum home laundry drier 1 is clearly inferable from the above description, with no further explanation required.
Clearly, changes may be made to the rotary-drum home laundry drier 1 as described herein without, however, departing from the scope of the present invention.
For example, in a different embodiment, the air cooling device 24 of hot-air generator 6 may comprise an air/air heat exchanger which is located inside the air recirculating conduit 22, preferably upstream of the centrifugal fan 23; and is structured for using the external air to cool down the airflow arriving from rotatable drum 3; whereas the air heating device 25 of hot-air generator 6 may consists in a resistor which is located inside the air recirculating conduit 22, downstream of the air/air heat exchanger and preferably also downstream of the centrifugal fan 23.
In a further non-shown embodiment, the supporting panel or bulkhead 14 of rear wall 2b lacks the sink-shaped bulge 15, and the pass-through opening 15a is made on a substantially flat, central portion of supporting bulkhead 14 encircled/surrounded by the gasket-supporting member 16.
In other words, in this embodiment the gasket-supporting member 16 surrounds/encircles a substantially flat, central portion of supporting bulkhead 14 which is aligned/faced to the back wall 9 of tubular body 3 and is fluidly connected to, i.e. communicates with, the hot-air generator 6 via the pass-through opening 15a.
With reference to Figure 2, the stream of hot air produced by the hot-air generator 6 preferably enters into the tubular body 3 through the permeable-to-air inner portion 9c of back wall 9, flows inside the tubular body 3 for the entire length of the latter, and comes out of the tubular body 3 through the front mouth of the tubular body 3 delimited by the front rim 3f, or vice versa.
In other words, the stream of hot air produced by hot-air generator 6 preferably enters into the tubular body 3 through an intake air-vent located in the rear wall 2b of the boxlike casing 2 substantially aligned/faced to the permeable-to-air inner portion 9c of the preferably dish-shaped back wall 9 of tubular body 3, and comes out of tubular body 3 through an escape air-vent which is preferably located either on the porthole door 4 that selectively closes the laundry loading/unloading opening 4a of front wall 2a, or on the front wall 2a of the boxlike casing 2, preferably very close to the laundry loading/unloading opening 4a.
In the example shown, the stream of hot air produced by hot-air generator 6 preferably comes out of the tubular body 3 via an escape air-vent incorporated in the preferably funnel-shaped coupling element of the front bulkhead 13 that delimits/surrounds the laundry loading/unloading opening 4a on front wall 2a.
With reference to Figures 2, 3 and 4, the intake air-vent of the hot-air generator 6 is incorporated into the rear wall 2b of boxlike casing 2.
With reference to Figures 6, 7 and 8 a second embodiment of the present invention is shown, which is similar to the first embodiment shown above with reference to Figures 1 to 5, and for that reason only the most relevant differences between the two embodiments will be herein below described in detail, thus avoiding to describe again portions of the rotary drum laundry dryer of the second embodiment which are identical to the same portions of the rotary drum laundry dryer of the first embodiment.
While in the first embodiment shown above with reference to Figures 1 to 5 the substantially cylindrical tubular body 3 of the rotatable drum has a back wall 9 permanently rigidly coupled to the circular rear rim 3b of the substantially cylindrical lateral wall 8, in such a second embodiment of the present invention shown in Figures 6, 7 and 8, the rotary-drum laundry dryer 1 comprises instead a substantially circular, basin-shaped lid or cover 21 fixed to the rear wall 2b of the casing 2 substantially coaxial to the tubular body 3, so as to form, on said rear wall 2b, a cavity which communicates with the hot-air generator 6, and in addition comprises a circular gasket-supporting collar 28 which has a nominal diameter greater than that of the rear rim 3b of the tubular body 3.
In other words, in such a second embodiment of the present invention shown in Figures 6 to 8, the rotary-drum laundry dryer 1 also comprises a substantially circular, dish- or basin-shaped lid or cover 21 which is firmly fixed to the rear wall 2b of casing 2 substantially coaxial to the longitudinal axis L of tubular body 3, and is dimensioned/shaped so as to completely cover and close the outwards-projecting bulge or recess 27 of the rear wall 2b to form an air duct or passageway for the hot air directed towards revolving drum 3; and a circular gasket-supporting collar 28 which has a nominal diameter greater than that of rear rim 3b, and is firmly fixed to the periphery of the basin-shaped lid or cover 21, and/or to the rear wall 2b of casing 2, so as to be coaxial to the longitudinal axis L of tubular body 3.
Both the basin-shaped lid or cover 21 and the gasket-supporting collar 28 are preferably, though not necessarily, made of metal material.
Preferably, basin-shaped lid or cover 21 is firmly fixed to the rear wall 2b of casing 2 in substantially airtight manner, with its concavity directly facing the bottom of the outwards-projecting bulge or recess 27 of the rear wall 2b, so as to form, on rear wall 2b, a substantially lenticular-shaped cavity which is suited to receive the hot air arriving from hot-air generator 6; whereas at least a portion of the bottom 21b of the basin-shaped lid or cover 21 is properly perforated, or at any rate permeable to air, to permit hot air to flow into revolving drum 3 or vice versa.
The circular rear sealing gasket 12 is force fitted into gasket-supporting collar 28, and is shaped so as to permanently come in abutment against the periphery of the basin-shaped lid or cover 21.
In the example shown, in particular, the circular rear sealing gasket 12 preferably, though not necessarily, consists of a monolithic, toroidal-shaped ring 12 made of rubber or other elastomeric polymer suitable to be force fitted into the circular gasket-supporting collar 28. Optionally, the toroidal-shaped ring 12 may also have a hollow structure, particularly when made of rubber or other elastomeric polymer.
With reference to Figures 6 to 8, in the example shown, moreover, the periphery of the basin-shaped lid or cover 21 is permanently fixed to the rear wall 2b of casing 2 preferably, though not necessarily, via seam-folding and/or clinching and/or riveting and/or spot-welding or similar; and an annular rear sealing gasket 16b is preferably, though not necessarily, interposed between the basin-shaped lid or cover 21 and the rear wall 2b of casing 2 to avoid undesired air leakages from the substantially lenticular-shaped cavity formed on rear wall 2b. Obviously the rear sealing gasket 16b surrounds the entrance or mouth of the outwards-projecting bulge or recess 27 on rear wall 2b.
Moreover, with reference to Figures 6 and 7, in the example shown the central section of the bottom 21b of the basin-shaped lid or cover 21 is preferably, though not necessarily, provided with a substantially circular, cup-shaped contra-oriented bulge or recess which projects towards the bottom of the outwards-projecting bulge or recess 27 of rear wall 2, so to locally reduce the thickness of the lenticular-shaped cavity formed on rear wall 2b and maximize the inner volume of revolving drum 3. Thus the basin-shaped lid or cover 21 has a substantially U-shaped peripheral annular portion which protrudes inside the revolving drum 3, and a substantially cup-shaped central portion which stick out of revolving drum 3 and protrudes inside the outwards-projecting bulge or recess 27 of rear wall 2b.
The perforated area of the basin-shaped lid or cover 21 is preferably, though not necessarily, located on the bottom of said contra-oriented bulge or recess.
As regards the circular gasket-supporting collar 28, with reference to Figures 6 to 8, the rear rim 3b of gasket-supporting collar 28 - i.e. the rim of collar 28 faced to rear wall 2b - is provided with one or more radially outwards-projecting winglet or flanges, which are structured to be permanently fixed to the periphery of the basin-shaped lid or cover 21 and/or optionally also to the rear wall 2b of casing 2 via seam-folding and/or clinching and/or riveting and/or spot-welding or similar, so as to firmly fix the gasket-supporting collar 28 on the periphery of the basin-shaped lid or cover 21, while remaining coaxial to the longitudinal axis L of tubular body 3.
Similar to what described with reference to the first embodiment, also in the present second embodiment the rotary-drum laundry dryer of the present invention further comprises at least a space compensating element 7b disposed in a portion of the rear annular gasket groove or seat 16b, the space compensating element 7b being radially interposed between the rear gasket groove or seat 16b and the relative rear sealing gasket 12. As shown in Figures 6 to 8, the rear gasket groove or seat 16b is wider than the relative rear sealing gasket 12 and the size difference between the rear gasket groove or seat 16b and the relative rear sealing gasket 12 is compensated by such a space compensating element 7b. Similarly, a space compensating element 7a is provided for being received in a front gasket groove or seat together with a front sealing gasket 11.
By this way, the same advantages related to the front/ rear sealing gasket 11, 12 and the relative front/rear gasket groove or seat 5, 16b housing such a front/ rear sealing gasket 11, 12, as obtained in the above disclosed first embodiment shown in Figures 1 to 5 due to the presence of such space compensating elements 7a, 7b, are still obtained in the present second embodiment shown in Figures 6 to 8 due to the presence of such space compensating elements 7b, even if in the second embodiment the rear portion of the rotary drum 3 has a closing structure which is different from the rear portion of the rotary drum 3 showed in the first embodiment.
An additional embodiment (not shown in the Figures) may be made in which a space compensating element 7a is disposed in a portion of such a front gasket groove or seat 5 only, while no space compensating elements are disposed in a portion of such a rear gasket groove or seat 16b. A further additional embodiment (not shown in the Figures) may be made in which a space compensating element 7b is disposed in a portion of such a rear gasket groove or seat 16b only, while no space compensating elements are disposed in a portion of such a front gasket groove or seat 5.
The same advantages obtained in the above disclosed first and/or second embodiment due to the presence of such a space compensating element 7a,7b may be still obtained in such additional embodiments.

Claims

Rotary-drum laundry dryer (1) comprising an outer casing (2) having a front wall (2a) and a rear wall (2b), a rotatable drum (3) which is structured for housing the laundry to be dried and is fixed in axially rotating manner inside the casing (2), the drum (3) being accessible by a user through a laundry loading/unloading opening (4a) closable by a door (4), and a hot-air generator (6) structured to circulate a stream of hot air through the rotatable drum (3);
the rotatable drum (3) comprising a substantially cylindrical, tubular body (3) which abuts against the front wall (2a) of the outer casing (2) so as to surround the laundry loading/unloading opening (4a) and is coupled in axially rotating manner to said front wall (2a) with the interposition of a front sealing gasket (11) between the tubular body (3) and the front wall (2a) of the outer casing (2), and which abuts against the rear wall (2b) of the outer casing (2) and is coupled in axially rotating manner to said rear wall (2b) with the interposition of a rear sealing gasket (12) between the tubular body (3) and the rear wall (2b) of the outer casing (2), each of said front sealing gasket (11) and/or rear sealing gasket (12) being housed in a corresponding front gasket groove or seat (5) and/or rear gasket groove or seat (16b),
being characterized in that the rotary-drum laundry dryer (1) further comprises at least a space compensating element (7a,7b) disposed in at least a portion of said front gasket groove or seat (5) and/or in at least a portion of said rear gasket groove or seat (16b).
Rotary-drum laundry dryer according to Claim 1, wherein said at least a space compensating element (7a,7b) is radially interposed between said front gasket groove or seat (5) and the front sealing gasket (11) and/or between said rear gasket groove or seat (16b) and the rear sealing gasket (12).
Rotary-drum laundry dryer according to Claim 1, wherein said at least a space compensating element (7a,7b) is interposed between said front gasket groove or seat (5) and the front sealing gasket (11) and/or between said rear gasket groove or seat (16b) and the rear sealing gasket (12) along a direction parallel to the drum rotational direction.
Rotary-drum laundry dryer according to any one of Claims 1 to 3, wherein said front gasket groove or seat (5) and/or said rear gasket groove or seat (16b) is wider than the relative front sealing gasket (11) and/or of rear sealing gasket (12) and each size difference between the gasket groove or seat (5,16b) and the relative gasket (11,12) is compensated by said space compensating element (7a,7b).
Rotary-drum laundry dryer according to any one of Claims 1 to 4, wherein said front sealing gasket (11) and/or rear sealing gasket (12) is hold in its corresponding gasket groove or seat (5,16b) by interposition of said at least a space compensating element (7a,7b).
Rotary-drum laundry dryer according to any one of Claims 1 to 5, wherein said at least a space compensating element (7a,7b) is substantially ring-shaped.
Rotary-drum laundry dryer according to any one of Claims 1 to 6, wherein said tubular body (3) comprises a front rim (3a) coupled in airtight and axially rotating manner to a front bulkhead (13) associated to the front wall (2a), so as to surround the laundry loading/unloading opening (4a), and wherein said front sealing gasket (12a) is interposed between said front rim (3a) of the tubular body (3) and the front bulkhead (13).
Rotary-drum laundry dryer according to 7, wherein said front rim (3a) is coupled in airtight and axially rotating manner to the periphery of a substantially funnel-shaped element which extends from said front wall (2a) of the casing (2) towards the tubular body (3), and is shaped so as to converge to the laundry loading/unloading opening (4a).
Rotary-drum laundry dryer according to any one of Claims 1 to 8, wherein said substantially cylindrical tubular body (3) of the rotatable drum has a back wall (9) rigidly connected thereto, the tubular body (3) being arranged so that said back wall (9) is coupled in substantially airtight and axially rotating manner to the rear wall (2b) of the casing (2) with the interposition of said rear sealing gasket (12), the rear wall (2b) of the outer casing (2) comprising: a substantially vertically-oriented supporting bulkhead (14) having a central portion (15) which is substantially aligned/faced to a permeable-to-air inner portion (9c) of the back wall (9) of the rotatable drum (3); and a gasket-supporting member (16) which is fixed/attached to the inner face of the supporting bulkhead (14) so to be interposed between the central portion (15) of said supporting bulkhead (14) and the back wall (9) of the tubular body (3), and which has a central pass-through opening (16a) substantially aligned/faced to the permeable-to-air inner portion (9c) of said back wall (9) and fluidly connected to the hot-air generator (6).
Rotary-drum laundry dryer according to Claim 9, wherein said supporting bulkhead (14) is fluidly connected to the hot-air generator (6) and said gasket-supporting member (16) is provided with said rear gasket groove or seat (16b) which is faced to the back wall (9) of the tubular body (3), encircles the central pass-through opening (16a) of the gasket-supporting member (16) and is shaped/ dimensioned so to house the rear sealing gasket (12) and keep said rear sealing gasket (12) in abutment against the back wall (9) of the tubular body (3).
Rotary-drum laundry dryer according to Claim 9 or 10, wherein the supporting bulkhead (14) is centrally provided with a substantially sink-shaped bulge (15) which is substantially aligned/faced to the permeable-to-air inner portion (9c) of the back wall (9) of said tubular body (3), protrudes outwards of the outer casing (2) and is fluidly connected to the hot-air generator (6).
Rotary-drum laundry dryer according to any one of Claims 9 to 11, wherein the gasket-supporting member (16) is substantially ring-shaped and dimensioned so to completely cover and/or surround the peripheral border of the sink-shaped bulge (15).
Rotary-drum laundry dryer according to any one of Claims 9 to 12, wherein the rear wall (2b) of the outer casing (2) furthermore comprises an outer lid or cover (18) which is rigidly attached to the outer face of the supporting bulkhead (14), and is suitably shaped/structured to fluidly connected the sink-shaped bulge (15) of the supporting bulkhead (14) to the hot-air generator (6), so as to channel the stream of hot air produced by the hot-air generator (6) towards the sink-shaped bulge (15), or vice versa.
Rotary-drum laundry dryer according to any one of Claims 1 to 8, wherein the rotary-drum laundry further comprises:
- a substantially circular, basin-shaped lid or cover (21) which is fixed to the rear wall (2b) of the casing (2) substantially coaxial to the tubular body (3), so as to form, on said rear wall (2b), a cavity which communicates with the hot-air generator (6); and

- a circular gasket-supporting collar (28) which has a nominal diameter greater than that of the rear rim of the tubular body (3), and is fixed to the periphery of the basin-shaped lid or cover (21) and/or to the rear wall (2b) of the casing (2), coaxial to the tubular body (3); the rear circular sealing gasket (12b) being force fitted into the gasket-supporting collar (28) so as to come in abutment against the periphery of the basin-shaped lid or cover (21) around the perimeter of the latter.
Rotary-drum laundry dryer according to Claim 14, wherein the rear wall (2b) of the casing (2) is provided with a substantially sink-shaped bulge or recess (27) which projects outwards the casing (2), is located inside the perimeter of the rear sealing gasket (12), and communicates with the hot-air generator (6); the basin-shaped lid or cover (21) being fixed to the rear wall (2b) of the casing (2) substantially coaxial to the tubular body (3), so as to close the outwards-projecting bulge or recess (27) made on the rear wall (2b) of the casing (2).