FR2534943A1 - DRYER HOUSEHOLD DRYER - Google Patents

Abstract

IN A DRYER EQUIPPED WITH A ROTATING DRUM 5 WITH LAUNDRY PROVIDED IN A BODY 1, A DEVIATION PLATE 12 AND AN ANNULAR SCREEN 27 PROTECT WALL 3 OF THE BODYWORK AND END 6 OF THE DRUM AGAINST DIRECT HEATING BY THE HEATING ELEMENTS 15. PLATE 12 AND SCREEN 27 ARE SHAPED SO THAT COLD AIR CAN PASS SUCCESSIVELY OVER THE OUTSIDE SURFACE OF PLATE 12, THROUGH AN ANNULAR SPACE 13 CONDUCTING AIR TO THE HEATING ELEMENTS 15, IN FRONT OF A THERMOSTAT 28 AND BY PERFORATIONS 16 PRACTICED AT THE END 6 OF THE DRUM. THIS ARRANGEMENT ENABLES THE LAUNDRY CONTAINED IN DRUM 5 TO BE DAMAGED AS A RESULT OF OVERHEATING OF THE ELEMENTS 15. APPLICATION: APPLIANCES.

Description

_ 1 _

  "Household drum dryer".

  The invention relates to a household dryer with a rotating laundry drum mounted in a body, a heating device and a fan producing a flow of air sweeping the heating device and passing through the drum from the one of its ends, said first, to the other, device

  heater which is placed between said first end of the drum and

  bour and a contiguous wall of the body and is mounted on a deflection plate disposed between the heater and said wall, this arrangement being such that before sweeping the heater, at least a portion of the air flow passes over most of the surface of the deflection plate looking at said wall to then pass through an annular space formed between

  the peripheral angular region of the plate and the first

tee of the drum.

  Such a dryer is known from United Kingdom Patent Application No. 2,095,806 A The deflection plate has two advantages; indeed, it prevents the wall of the body is heated by the direct radiation of the heating device and ensures the preheating of the air before it passes through

  the annular space and passes on the heater.

  In addition, the plate is cooled by the passage of air

  cold on its surface lying on the side of the wall.

  Said patent application also recommends a dryer in which the heating device is connected to a thermostat that reacts to the temperature of the deflection plate The thermostat disconnects the heating device if the temperature of the plate

  exceeds a certain value and thus protects the dryer and the linen.

  ge in the drum of possible damage occurring in the case of a limitation of the air flow due, for example, to the presence of an excess of lint on the lint filter, to the overload of the drum or blocking the air outlet channel of the machine. However, we realized that because of the capacity

  relatively large thermal range of the deflection plate, the function

  Thermostat may be relatively slow if the airflow is stopped or inadvertently weakened. In some cases, it is possible that the laundry, contained in the drum, which may be in contact with said first end of the drum, either scorched or otherwise damaged as a result of the heating of a part of this end under the effect of the direct radiation of the heating device In addition, if at the level of the heating device, this end is perforated with air intake holes, the linen may be affected by the direct radiation of the device

of heating.

  The aim of the invention is to reduce at least the risk of

such damage to the laundry.

  For this purpose, according to the invention, an electric dryer

  of the kind described in the preamble is remarkable in that

  that the first end of the drum carries an annular metal screen

  designed to put said first end away from the

  heating device, and that the heating device is connected to a thermostat that reacts to the temperature

  air downstream of the heating device, between the heating plate

viation and the screen -

  The annular screen protects the end of the drum from the direct thermal radiation of the heating device, while it also serves to distribute the heat emitted over a relatively large area by thermal conduction and convection As the thermostat

  reacts to the air temperature at the heating device

  ge, it disconnects the heater faster than in

  the case where it reacts only to the temperature of the deviation plate

  In this way, the risk of damage is substantially eliminated.

  thermal management of the dryer or drum contents.

  If the ring screen is attached to the drum following its

  outer wall and that the major part of the screen is separated from the first end of the drum and the first end of the drum has perforations at the screen, at least a portion of the heated air flow passes between the screen and said first end of the drum Thus, the screen increases the length of the path of the heated air while ensuring better mixing of the air,

  so that the temperature of the air arriving at the laundry is more uniform.

  form. The dryer may be of the so-called vacuum type, or vacuum type, in which the vacuum cleaner is arranged between the drum and the opening of

  air outlet from the bodywork, the air being sucked-through the drum

  bour A dryer of this kind is described in the patent application

  It is also possible that it is of the type referred to as

  sion, in which the fan blows air through the drum.

  The following description, with reference to the attached drawing,

  will better understand how the invention is realized.

  Figure 1 shows a dryer of the suction type.

  Figure 2 shows on an enlarged scale a portion of

  from the chute of Figure 1, including the thermostat.

  Figure 3 shows a drier of the pressure type.

  The dryer of Figures 1 and 2 comprises a body 1 provided with a front wall 2 and a rear wall 3 On the wall

  front 2 is mounted a door 4 which gives access to the part inte-

  upper of a rotary drum 5 whose rear wall 6 is provided with a central pivot 7 (which has been shown only schematically) so that the drum can be driven in a rotary movement about its horizontal axis by a motor 8 and through a

  belt or other drive means (not shown).

  The motor 8 also drives a fan 9 to pallets

  which draws air into the bodywork through openings in

  trea '11 practiced in the rear wall 3, air which is brought to pas-

  serially on the rear surface of a circular deflection plate 12 fixed in the center of the rear wall, by an annular opening 13 formed between, on the one hand, the periphery of the deflection plate 12 and, on the other hand, an annular projection 14 of the wall

  rear 6 of the drum 5, on a pair of heating elements 15 sen-

  circularly, through apertures 16 made in the paper.

  rear king 6 of the drum 5, by the drum and the laundry contained therein, by an annular opening 17 formed between the door 4 and an annular rim 18 on the front wall 19 of the drum 5, by a perforated collar 21 of protection on the door 4, by a suction channel 22 surrounding the door 4 and by the fan 9 to pallets, after which the sucked air is discharged from the body through an outlet channel 23 and an outlet opening 24 In the -4 - embodiment shown, it is also sucked from the air in Warrosserie 1 through an inlet opening 25 formed in the front wall 2 The general directions that follows the air flow in the body, are indicated by arrows in FIG. 1 Preferably, the openings 11 are provided with blades

  awning, as shown in Figure 2.

  In the intended embodiment, to improve the path that the airflow follows, the air inlet aperture 25 in the front wall of the bodywork and the outlet opening 24 in the rear wall are provided. It should be noted that the opening 25 is optional with regard to its presence as well as its place. It is also possible for the opening 24 to be made in another part of the bodywork, for example in

  the lower part of the front wall 2 of the bodywork -

  If, for the sake of clarity, the openings 11

  air intake was assumed to be absent, the heat transferred

  The heating elements 15 to the deflector plate 12 would be largely sufficient for heating the rear wall 3.

  the heat would not only be lost, but could also

  to prevent overheating of the rear wall and, consequently,

  possible damage to neighboring equipment The presence of the inlet openings 11 overcomes these difficulties First, the cold air passing over the rear surface of the deflector plate 12 keeps the plate relatively cold and substantially prevents the increase In the second place, the heat of the plate is used to preheat the incoming air through the annular opening 13, so that this heat is not

  lost Thus, the efficiency of the dryer is increased.

  It should be noted that some of the elements which are commonly used in tumble dryers but which are not of interest in the context of the invention, are not shown.

  In this case, the door is equipped with a hermetic seal

  plunging against the frontrale wall of the bodywork to prevent air being sucked through the intermediate space In addition, the front end of the drum 5 is rotatably supported by the annular projection 18 mounted on an annular collar 26 forming

  part of the suction channel housing.

  An annular metal screen 27 is fastened, for example, by rivets 33 (FIG. 2) or by spot welds, along its outer peripheral edge to the projection 14 of the rear wall 6 although the screen 27 may be placed at immediate proximity of the rear end to most of its surface, it is preferably separated from the end 6 by a space over most of its surface, as shown in FIGS.

  2 In this case, a certain amount of air passes through the

  pace between the screen 27 and the end 6 of the drum for

  then pour the perforations 16, as shown by the arrows

  This air passage reduces the heating from end 6 to

  of the screen 27 under the effect of a direct radiation emitted by

the screen 27.

  The temperature of the airflow passing between the deflection plate 12 and the screen-27 is measured by a thermostat 28 under

  the action of which the heating elements are disconnected if the temperature

  The temperature exceeds a given value, 1500 C for example, in the range between 1300 C and 170 ° C. The thermostat 28 is fixed to the plate 12 and is thermally insulated therefrom by a layer 29 (FIG. 2) of insulating material. and because of this, it works relatively

  quickly in the case of overheating in order to avoid damage

  temperature of the dryer or laundry in the drum 5.

  FIG. 2 also shows a thermal circuit breaker

  31 to maximum which is mounted on a locally flattened extension 32 of the deflection plate 12 With this local flattening of the plate 12, the width of the annular space 13 is greater in the region which is in the immediate vicinity of the circuit breaker 31, so that the flow of air through this space is not substantially reduced in this region Such an arrangement eliminates the possibility that in this region, there appears a "hot spot" -on

  The heating elements 15 The circuit breaker 31 constitutes a device

  additional safety device to protect the load of

  against a complete interruption of the air flow, due, for example,

  if the drive motor fails or when the output channel is blocked. Normally, this circuit breaker is swept by

  cold air, but if the airflow is cut off, hot air

  Heaters 15 pass over this circuit breaker so that it starts to operate, for example, at 1450 C. FIG. 3 shows an embodiment of a

  pressure type dryer, parts of Figure 3 which correspond to

  lay to portions shown in Figs. 3 being indicated

by the same references.

  -In this case, the fan 9 draws air into the body 1 through the inlet 25 formed in the wall 34 of the body 1 The only outlet for air that has been forced into the bodywork through the fan 9, is formed by perforations (not shown) practiced in the

  door 32, so that air pressure is established in the car-

  The cold air of the fan 9 can circulate freely in the space between the deflection plate 12 and the rear wall 34 of the body. The air is forced to pass successively through

  the annular space separating the drum projection 14 and the peripheral

  deflection plate 12, through the perforations 16 formed in the rear end 6 of the drum 5 and through a load of laundry contained in the drum to be evacuated thereafter through

  the perforations in the door 32 by crossing normally a thread

anticharpie not shown.

  The arrangement of the deflection plate 12, elements

  15, the annular screen 27, the thermostat 28, the cutter

  thermal circuit 31 and the extension 32 of the plate 12 is identical.

  to that shown in Figure 2 However, in the

  this, the rear wall of the bodywork has no entries

of air 11.

  Although the embodiments described with reference to the accompanying drawings relate to porthole dryers, it is obvious

  that the invention also applies to a load-type dryer

  from the top For a top loading dryer, access

  drum can be obtained by means of a door placed in the

  upper face of the body and a second door placed in the curved surface of the drum The ends of the drum can

  located near the respective side walls of the car-

  while the plate supporting the heating elements can be arranged between one of these ends on the one hand and the

  contiguous side wall of the bodywork on the other hand.

-7-

Claims (4)

CLAIMS:   An appliance dryer having a rotating laundry drum (5) mounted in a body (1), a heater (15) and a fan (9) producing a flow of air sweeping the   heating and passing through the drum from one of its extremes   (6), said first, to the other, heater (15) which is located between said first end of the drum and a contiguous wall (3) of the body and is mounted on a deflection plate (12). ) arranged between the heating device (15) and said wall, this arrangement being such that before sweeping the heating device, at least a portion of the flow of air passes over   most of the surface of the deflection plate (12) is   guarding said wall to then pass through an annular space (13) formed between the peripheral angular region of the plate and the preo   first end of the drum, characterized in that the first end   the drum has an annular metal screen (27) for preventing said first end (6) from the direct radiation of the heater (15), and that the heater is connected to a thermostat (28); ) responsive to the temperature of the air downstream of the heater (15), between the deflection (12) and the screen (27).   Electric household dryer according to claim 1, characterized   in that the screen (27) is fixed to the drum according to its periph-   outermost region, the major part of the screen being separated by a space of the first end of the drum, and in that the first end (6) of the drum has perforations (16) at the screen, at least one part of the heated air flow passing between the screen and said first end   3. Appliance dryer according to claim 2, characterized   in that the thermostat (28) has been designed to disconnect the heater (15) at an air temperature of between  C and 170 C.   4. Domestic appliance dryer according to any one of the   a thermal circuit breaker (31) at a maximum is placed in the path of the air flow downstream of the heating element (15), and in that this circuit breaker (31) ) is arranged with respect to the heating device so that, when the heating device (15) is operating, the air flow sweeping the heating device is strongly impeded or is cut off, the circuit breaker ( 31) is heated by the device   heating (15) and disconnects it.