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(11) | EP 2 669 420 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Laundry drying machine |
| (57) The present invention relates to a laundry drying machine (1) comprising a casing
(2), a laundry chamber suitable for receiving the laundry to be dried, a moisture
condensing device, a bottom part (16) comprising a basement (14). A bottom closing
element (7; 57; 77) is applicable to the basement (14) in a side thereof (17) facing
the floor where said machine (1) rests. The bottom closing element (7; 57; 77) comprises
an area (25; 65) suitable for collecting a liquid dripping from the bottom part (16)
of the machine (1).
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FIELD OF THE INVENTION
[0001] The present invention concerns the technical field of laundry drying machine, such as a laundry washer-dryer or a laundry dryer, especially of condenser type. In particular, the present invention refers to laundry drying machines of condenser type provided with a lower tank, i.e. a tank placed on the bottom part of the machine, for collecting moisture removed from wet laundry by means of a condensing unit which is passed through by drying air.
BACKGROUND ART
[0002] Laundry drying machines capable of carrying out a drying process on laundry generally comprise a casing that houses a laundry container, like a rotating drum, where laundry to be dried is received, a basement portion having seats for receiving machine operational devices and an air circuit for carrying out drying operation by circulating hot air through the laundry container. Air circulating means and heating means are provided in the air circuit for circulating and heating drying air, respectively. In laundry drying machines of condenser type, condensing means are further provided in the air circuit for removing moisture from drying air passing through wet laundry to be treated thereby allowing said air to be recirculated cyclically within the air circuit. Moisture removed from laundry is collected in a tank which has to be periodically emptied by a user. Washing and drying machines, i.e. appliances provided for performing laundry washing and drying operations in a single machine are also known and generally comprise a washing arrangement for allowing washing of the laundry and a drying arrangement as described before for drying laundry.
[0003] In the following description the invention will be disclosed, therefore, with reference to a machine suitable for carrying out a drying operation on laundry such as a laundry washing and drying machine or a laundry drying machine, hereinafter referred to as dryer.
[0004] In known condenser type laundry dryer the cited condensing means for condensing moisture in the air circuit are arranged in the basement portion of the dryer. The condensing means may comprise, for example, an air-air heat exchanger or an evaporator of a heat pump system of the dryer.
[0005] Water generated by moisture removed by said condensing means is collected in a removable tank arranged in a seat realized in the basement below the condensing means. The condensed water flows through a proper path and drips into the tank by gravity.
[0006] The removable tank is slidably inserted in the seat and a valve is provided between the seat and the tank to properly interrupt the water flow when the tank is extracted by a user.
[0007] When the tank is extracted by a user, a small quantity of water usually leaks out of the valve. In order to collect this water leakage and in order to avoid it falls down on the floor, a water drip catcher is opportunely placed below the valve. The water collected by the water drip catcher then evaporates. The water drip catcher is usually formed by a receptacle which is connected to the basement or to the tank in a position placed just below the valve.
[0008] However, the laundry drying machines above described belonging to the known art pose some drawbacks.
[0009] A first drawback of this known technique is constituted by the structural complexity deriving from the necessity of an additional specific component, i.e. the water drip catcher, which has to be fixed to the basement.
[0011] Another drawback posed by this known technique is constituted by the fact that the water drip catcher is bulky and the tank volume must be opportunely reduced to create a space for receiving the water drip catcher so as to avoid interference between them.
[0013] In particular, it is one object of the present invention to provide a laundry drying machine which has a reduced constructional complexity with respect to the machines of known type.
[0014] Another object of the invention is to provide a laundry drying machine which is easy to assemble.
[0015] Still another object of the present invention is to provide a laundry drying machine having an improved capacity of collecting water accidentally dropped when removing a condensate storage tank from the machine.
[0016] A further object of the invention is to provide a laundry drying machine with reduced production cost.
[0017] Advantages, objects, and features of the invention will be set forth in part in the description and drawings which follow and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
DISCLOSURE OF INVENTION
[0018] The applicant has found that by providing a laundry drying machine, such as a laundry washer-dryer or a laundry dryer, comprising a casing, a laundry chamber suitable for receiving the laundry to be dried, a bottom part, a bottom closing element applicable to said bottom part in a side thereof facing the floor where said machine rests and by providing an area in said bottom closing element suitable for collecting a liquid dripping from said bottom part of said machine it is possible to obtain a laundry drying machine having a reduced constructional complexity with respect to the systems of known type.
[0019] The present invention relates, therefore, to a laundry drying machine comprising a casing, a laundry chamber suitable for receiving the laundry to be dried, a moisture condensing device, a bottom part comprising a basement and a bottom closing element applicable to said basement in a side thereof facing the floor where said machine rests; wherein said bottom closing element comprises an area suitable for collecting a liquid dripping from said bottom part of said machine. Preferably the collecting area comprises a floor portion and a peripheral edge protruding from the floor portion. More preferably, the peripheral edge is V-shaped.
[0020] According to a preferred embodiment of the invention, the basement comprises a seat suitable for receiving a removable tank for collecting the condensed water from the condensing device.
[0021] Advantageously, the removable tank is displaced between the bottom closing element and a lower side of the basement.
[0022] Opportunely, the device comprises a connecting device fluidly connecting the basement to the removable tank for conveying the condensed water from the condensing device to the removable tank.
[0023] Preferably, the collecting area is defined in the bottom closing element in a position beneath the connecting device.
[0024] Advantageously the liquid dripping from the bottom part which is collected in the collecting area is water leakage coming from of the connecting device.
[0025] In a first preferred embodiment of the invention, the connecting device comprises a valve which is open when the removable tank is connected to the basement and is closed when the removable tank is being removed from the basement.
[0026] According to a preferred embodiment of the invention, the basement further comprises a collecting housing for collecting the condensed water before it is conveyed to the removable tank and the machine further comprises a connecting device fluidly connecting the collecting housing to the removable tank. Preferably the condensing device comprises an air-air heat exchanger. Alternatively, the condensing device comprises a refrigerant fluid evaporating device of a heat pump system.
[0027] Advantageously, the basement comprises air paths for conveying moist air coming from the laundry chamber to the moisture condensing device and/or air paths for conveying a cooling air flow to the moisture condensing device. Preferably the machine further comprises sliding guides allowing the removable tank to slide relative to the basement.
[0028] In a preferred embodiment of the invention, the sliding guides are formed in the moisture tank and in the basement.
[0029] In a further preferred embodiment of the invention, the sliding guides are formed in the moisture tank and in the bottom closing element.
[0030] Preferably, the sliding guides formed in the bottom closing element form part of the collecting area.
[0031] Advantageously, the bottom closing element and the collecting area are obtained from a plastic sheet subjected to a thermoforming process.
[0032] Preferably, also the sliding guides formed in the bottom closing element are obtained from a plastic sheet subjected to a thermoforming process together with the bottom closing element.
[0033] In a first preferred embodiment of the invention, the basement comprises an upper shell and a lower shell connectable one to the other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate possible embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings, corresponding characteristics and/or components are identified by the same reference numbers. In particular:
- Figure 1 shows an exploded perspective view of a laundry drying machine according to a preferred embodiment of the invention;
- Figure 2 shows a perspective bottom view of the basement of the laundry drying machine of Figure 1 with the removable tank in a first operating condition;
- Figure 3 shows a frontal side view of the basement of Figure 3;
- Figure 4 shows a sectional view taken along line IV-IV of Figure 3;
- Figure 4A shows an enlarged detail of Figure 4;
- Figure 5 shows a perspective bottom view of the basement of the laundry drying machine of Figure 1 with the removable tank in another operating condition;
- Figure 6 shows a frontal side view of the basement of Figure 5;
- Figure 7 shows a sectional view taken along line VII-VII of Figure 6;
- Figure 7A shows an enlarged detail of Figure 7;
- Figure 8 shows an exploded perspective view of the basement of Figure 2.
- Figure 9 shows a plan view of the bottom closing element of Figure 8;
- Figure 9A shows an enlarged sectional view taken along line IX-IX of Figure 9;
- Figure 10 shows a perspective view of the bottom closing element according to a second embodiment of the present invention;
- Figure 11 shows a perspective view of the bottom closing element according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The present invention has proved to be particularly successful when applied to a front-loading drying machine of the condenser type provided with an air-air heat exchanger; however it is clear that the present invention can be applied to any type of laundry drying machine, for example to a laundry drying machine provided with a heat pump system where the condensation of the moist air is carried out by the evaporator of the heat pump system.
[0036] With reference to Figure 1, reference number 1 indicates as a whole a laundry drying machine 1, hereinafter referred to as dryer.
[0037] The dryer 1 preferably comprises, though not necessarily, a substantially parallelepiped-shaped outer boxlike casing 2 which is preferably structured for resting on the floor and a preferably, though not necessarily, substantially cylindrical rotatable drum (not shown) which is structured for housing the laundry to be dried.
[0038] The drum preferably has its front opening or mouth directly facing a laundry loading/unloading pass-through opening provided in the front wall 2a of the boxlike casing 2. A front door 8, pivotally coupled to the front upright side wall 2a, is provided for allowing access to the drum interior region to place laundry to be dried therein.
[0039] The drier 1 also comprises a hot-air-generating device (not shown) for generating a drying air stream passing through the laundry drum to dry the laundry.
[0040] The dryer 1 of the invention is of the condenser type, i.e. of the type in which drying air is re-circulated through the drum in a closed loop, and comprises a condensing device, not illustrated, arranged along the drying air path downstream the laundry drum considering the direction of the drying air flow. The hot air produced by the hot-air-generating device removes moisture from laundry in the drum and the moist air then passes through the condensing device.
[0041] Preferably, the condensing device is in the form of an air-air cross-flow type heat exchanger. The moist air passing through the condensing device is cooled by a cooling air flow passing through the condensing device itself. The cooled and also dehumidified air is then conveyed again to the hot-air-generating device.
[0042] In further embodiments, the condensing device may be of different type, such as an evaporator unit of a heat pump system arranged in the dryer casing for heating the drying air stream and condensing moisture in the air stream leaving the drum. Advantageously the condensing device is arranged in the bottom part 16 of the dryer 1.
[0043] The bottom part 16 of the dryer 1 preferably comprises a basement 14 arranged inside the casing 2. Such basement 14 is illustrated in figures from 2 to 8 separated from the rest of the machine.
[0044] The basement 14 is preferably made by two portions, an upper shell 14a and a lower shell 14b, which are properly connected one to the other, preferably by means of screws or snap-in connections.
[0045] The basement 14 is preferably made of polymeric material and further preferably it is made by an injection moulding process. The basement 14 advantageously comprises a seat 15 where the air-air heat exchanger is arranged.
[0046] The basement 14 is opportunely shaped so as to create air paths for conveying moist air coming from the laundry chamber, i.e. the drum inner region, to the air-air heat exchanger and also air paths for the cooling air flow.
[0047] After the moist air has been cooled and dehumidified by the heat exchanger, condensation water is formed and advantageously collected in a housing 26 of the basement 14, better visible in Figure 4. The collecting housing 26 is opportunely formed at the rear of the basement 14 and the condensed water is conveyed therein through an inclined surface 27 which is realized below the seat 15 of the air-air heat exchanger.
[0048] From the collecting housing 26 the condensed water flows in an extractable moisture tank 9 located substantially beneath the seat 15 of heat exchanger.
[0049] The moisture tank 9 is preferably in the form of a drawer slidably arranged in a seat 43 on the lower side 18 of the basement 14 so that it can be easily and periodically emptied by a user.
[0050] At this purpose, sliding guides 41, 42 are formed in the moisture tank 9 and in the basement 14 for allowing the tank 9 to slide relative to the basement 14.
[0051] In different embodiments such sliding guides may be arranged differently, as illustrated and described later with reference to Figures 10 and 11.
[0052] The moisture tank 9 may be positioned in a first operating condition, or normal operating position as illustrated in Figures from 2 to 4, in which it is completely inserted in the basement 14 and can receive condensed water from the collecting housing 26.
[0053] The moisture tank 9 may then be moved in a non-operating condition, as illustrated for example in Figures from 5 to 7, when its extraction from the basement 14 occurs.
[0054] The collecting housing 26 and the moisture tank 9 are connected by means of a valve device 20.
[0055] The valve 20 comprises a first portion 21 (female) at the basement side and a second portion 22 (male) at the tank side. The female valve portion 21 is preferably positioned at the bottom of the collecting housing 26 and the male valve portion 22 is preferably positioned at a rear side of the tank 9 which faces the collecting housing 26.
[0056] The female valve portion 21 preferably comprises a sliding element 21a which is maintained in a closing position when the moisture tank 9 is in its non-operating condition, i.e. the tank 9 is moved for its extraction from the basement 14, as illustrated in Figure 7A. The sliding element 21a is preferably maintained in its closing position through elastic means, more preferably by a spring, not illustrated. When the sliding element 21a is in its closing position the female valve portion 21 blocks the water in the collecting housing 26.
[0057] When the moisture tank 9 is in its first operating condition, the sliding element 21a is moved in its opening position, as illustrated in Figure 4A, allowing the water to flow out from the collecting housing 26.
[0058] Analogously, the male valve portion 22 preferably comprises a sliding element 22a which is maintained in a closing position when the moisture tank 9 is in its non-operating condition, i.e. the tank 9 is moved for its extraction from the basement 14, as illustrated in Figure 7A. The sliding element 22a is preferably maintained in its closing position through elastic means, more preferably by a spring, not illustrated. When the sliding element 22a is in its closing position the male valve portion 22 blocks the water in the moisture tank 9.
[0059] When the moisture tank 9 is in its first operating condition, the sliding element 22a is moved in its opening position, as illustrated in Figure 4A, allowing the water coming from the collecting housing 26 to flow into the moisture tank 9.
[0060] Practically, when the moisture tank 9 is in its first operating condition, the valve 20 forms a fluid pathway from the collecting housing 26 to the interior region of the moisture tank 9 allowing the condensed water to fill the tank 9.
[0061] When the moisture tank 9 is in its non-operating condition, i.e. the tank 9 is moved for its extraction from the basement 14, the valve 20 interrupts the water flow and the tank 9 may be safety completely extracted. The valve 20 hence blocks the water in the collecting housing 26 and in the tank 9.
[0062] It is clear that in different embodiments any type of device having said valve function may be provided.
[0063] A bottom closing element 7 is removably mounted onto a lower side 36 of the bottom part 16 of the dryer 1, as illustrated in Figure 1. The lower side 36 of the bottom part 16 of the dryer 1 is the side of the bottom part 16 which faces the floor on which the dryer 1 is installed.
[0064] In a preferred further embodiment, the bottom closing element 7 is removably mounted directly onto the casing 2.
[0065] More preferably, as illustrated for example in Figure 2, the bottom closing element 7 is removably mounted onto a lower side 17 of the basement 14. The lower side 17 of the basement 14 is the side of the basement 14 which faces the floor on which the dryer 1 is installed. The bottom closing element 7 preferably closes, in a substantially air-tight manner, the lower part of air paths formed in the basement 14 for conveying a cooling air flow from the external environment to the inner region of the casing 2, i.e. inside the machine body.
[0066] The bottom closing element 7 preferably comprises a lowered central portion 7a suitable for receiving the tank 9.
[0067] According to the invention, the bottom closing element 7 preferably comprises an area 25 suitable for collecting a quantity of water dripping from the basement 14. More preferably, the collecting area 25 is suitable for collecting water leakage from the valve device 20.
[0068] During extraction of the moisture tank 9, in fact, due to the inertia of the valve closure, a little amount of water leakage drips from the valve 20, in particular from the female portion 21 of the valve 20.
[0069] The collecting area 25 is advantageously vertically aligned with the valve 20, and in particular vertically aligned with the female portion 21 of the valve 20. The extent of the collecting area 25 is preferably slightly greater than the extent of the valve 20. This permits that during the extraction phase of the tank 9, as illustrated for example in Figure 7, in a first part of the tank sliding path the water leakage is collected in the collecting area 25 avoiding it falls on the floor.
[0071] The moisture tank 9 in its lower side 9a preferably comprises a recessed portion 29 which is suitable for receiving the collecting area 25 when the moisture tank 9 is positioned in its first operating condition.
[0072] This recessed portion 29 advantageously have reduced dimensions with respect to the analogue recessed portion of the tank of the known machines which receive a water drip catcher mounted onto the basement. The volume of the tank 9, i.e. its capacity, is therefore increased with respect to the tank used in the machines of known type.
[0073] The collecting area 25 is preferably formed by a substantially concave surface, as better visible in Figures 9 and 9A, comprising a central floor portion 25b and a peripheral edge 25a protruding from the central floor portion 25b.
[0075] The peripheral edge 25a, the central floor portion 25b and the remaining area of the bottom closing element 7 have substantially, and preferably, the same thickness W.
[0076] The bottom closing element 7 may therefore be preferably obtained with a thermoforming process. In said thermoforming process a plastic sheet of thickness W is heated to a pliable forming temperature and then formed to the specific desired shape in a mold. The plastic sheet used in the process preferably comprises a polypropylene panel.
[0077] The realization of the bottom closing element 7 with a thermoforming process is cost saving. Furthermore, shape and the extent of the collecting area 25 may be easily and quickly changed. For example, the extent of the collecting area 25 may be advantageously increased in order to decrease the time necessary for water evaporation.
[0078] The provision of the bottom closing element 7 of the present invention avoids the use of any additional component for the water leakage, as the drip catcher of the prior art. This advantageously reduces the complexity of the machine and its assembly process because the same bottom closing element 7 may perform different tasks such as closing the lower part of air paths formed in the basement 14 for conveying a cooling air flow from the external environment to the inner region of the casing 2, carrying air inlet/outlet ports for said air paths, and further carrying the water collecting area 25 .
[0079] Installation of the bottom closing element 7 of the invention is actually simplified with respect to the known art where the additional element, namely the water drip catcher, has to be handled and mounted separately.
[0081] The bottom closing element 7 preferably closes almost the entire surface of the lower side 17 of the basement 14, and in general the lower side 16 of the dryer 1. In further embodiments, nevertheless, the bottom closing element could have a different extent, for example partially closing of the lower side 16 of the dryer 1, while keeping the collecting area 25 in the right position which respect to the valve 20.
[0082] The four vertices of the lower side 16 of the dryer 1 are advantageously provided also with feet, not illustrated. Said feet are preferably adjustable in height, in order to favour the stable positioning of the dryer 1 on the floor.
[0083] With reference to Figure 10, a construction variant of the bottom closing element 57 is described.
[0084] The bottom closing element 57 preferably comprises an area 65 suitable for collecting a quantity of water dripping from the basement 14. More preferably, the collecting area 65 is suitable for collecting water leakage from a valve device. The extent of the collecting area 65 is greater than the extent of the collecting area 25 above described with reference the first preferred embodiment of the invention. The collecting area 65 may receive a large quantity of water leakage. The collecting area 65 is preferably formed by a central floor portion 65b and a peripheral edge 65a protruding from the central floor portion 65b.
[0086] Preferably, parallel portions 65a' and 65a" of the peripheral edge 65a may also form respective sliding guides for the removable tank 9. The parallel portions 65a' and 65a" advantageously allows the tank 9 to slide relative to the basement 14.
[0087] In this case, the moisture tank 9 will be directly supported and guided by the parallel portions 65a' and 65a".
[0088] Advantageously, the bottom closing element 57 with the collecting area 65 may be obtained with a thermoforming process thus achieving the advantages above mentioned for the first preferred embodiment of the invention.
[0089] With reference to Figure 11, a further construction variant of the bottom closing element 77 is described.
[0090] The bottom closing element 77 preferably comprises an area 25 suitable for collecting a quantity of water dripping from the basement 14, which is of the type above described with reference to the first preferred embodiment.
[0091] The collecting area 25, therefore, comprises a central floor portion 25b and a peripheral edge 25a protruding from the central floor portion 25b.
[0092] The bottom closing element 77 further comprises two parallel protruding portions 85' and 85" forming respective sliding guides for the removable tank 9. The protruding portions 85' and 85" advantageously allow the tank 9 to slide relative to the basement 14.
[0093] In this case, the moisture tank 9 will be directly supported and guided by the protruding portions 85' and 85".
[0094] Advantageously, the bottom closing element 77 with the collecting area 25 and the protruding portions 85' and 85" may be obtained with a thermoforming process thus achieving the advantages above mentioned.
[0095] Clearly, changes may be made to the bottom closing element as described herein without, however, departing from the scope of the present invention. For example any suitable shape for the collecting area and its peripheral edge may be provided.
[0096] Conclusively it can be stated that a laundry drying machine, such as a laundry washer-dryer or a laundry dryer, according to the invention has an efficient arrangement for its lower portion. Thanks to this arrangement, complexity, costs and assembly time may be reduced.
[0097] It has thus been shown that the present invention allows all the set objects to be achieved. In particular, it makes it possible to obtain a laundry drying machine having a reduced constructional complexity with respect to the systems of known type.
[0098] Clearly, changes may be made to the laundry drying machine as described herein without, however, departing from the scope of the present invention. For example, the valve device may be placed in any position between the tank and the basement.
[0099] Although illustrative embodiments of the present invention have been described herein with reference to the accompany drawings, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
1. A laundry drying machine (1) comprising a casing (2), a laundry chamber suitable for
receiving the laundry to be dried, a moisture condensing device, a bottom part (16)
comprising a basement (14) and a bottom closing element (7; 57; 77) applicable to
said basement (14) in a side thereof (17) facing the floor where said machine (1)
rests; characterized in that said bottom closing element (7; 57; 77) comprises an area (25; 65) suitable for collecting
a liquid dripping from said bottom part (16) of said machine (1).
2. A machine (1) according to claim 1, characterized in that said collecting area (25; 65) comprises a floor portion (25b; 65b) and a peripheral
edge (25a; 65a) protruding from said floor portion (25b; 65b).
3. A machine (1) according to claim 1 or 2, characterized in that said basement (14) comprises a seat (43) suitable for receiving a removable tank
(9) for collecting the condensed water from said condensing device.
4. A machine (1) according to claim 3, characterized in that said removable tank (9) is displaced between said bottom closing element (7; 57;
77) and a lower side (18) of said basement (14).
5. A machine (1) according to any preceding claim, characterized in that it comprises a removable tank (9) for collecting the condensed water from said condensing
device, a connecting device (20) fluidly connecting said basement (14) to said removable
tank (9) for conveying said condensed water from said condensing device to said removable
tank (9).
6. A machine (1) according to claim 5, characterized in that said collecting area (25; 65) is defined in said bottom closing element (7; 57; 77)
in a position beneath said connecting device (20).
7. A machine (1) according to claim 5 or 6, characterized in that said connecting device comprises a valve (20) which is open when said removable tank
(9) is connected to said basement (14) and is closed when said removable tank (9)
is being removed from said basement (14).
8. A machine (1) according to any preceding claim, characterized in that said basement (14) further comprises a collecting housing (26) for collecting the
condensed water before it is conveyed to a removable tank (9) and the machine (1)
further comprises a connecting device (20) fluidly connecting said collecting housing
(26) to said removable tank (9).
9. A machine (1) according to any preceding claims, characterized in that said condensing device comprises an air-air heat exchanger or comprises a refrigerant
fluid evaporating device of a heat pump system.
10. A machine (1) according to any preceding claim, characterized in that said basement (14) comprises air paths for conveying moist air coming from said laundry
chamber to said condensing device and/or air paths for conveying a cooling air flow
to said condensing device.
11. A machine (1) according to any claims from 3 to 10, characterized in that it further comprises sliding guides (41, 42; 65a', 65a"; 85', 85") allowing said
removable tank (9) to slide relative to said basement (14).
12. A machine (1) according to claim 11, characterized in that said sliding guides (41, 42) are formed in said moisture tank (9) and in said basement
(14).
13. A machine (1) according to claim 11, characterized in that said sliding guides (41; 65a', 65a"; 85', 85") are formed in said moisture tank (9)
and in said bottom closing element (7; 57; 77).
14. A machine (1) according to claim 13, characterized in that said sliding guides (65a', 65a") formed in said bottom closing element (57) form
part of said collecting area (65).
15. A machine (1) according to any preceding claim, characterized in that said bottom closing element (7; 57; 77) and said collecting area (25; 65) are obtained
from a plastic sheet subjected to a thermoforming process.