FR2667626A1 - DRYER WITH TIMER. - Google Patents

Abstract

Tumble dryer with electric resistance (23, 26) for heating and timer to adjust the operating time. This tumble dryer includes a fan to circulate air on the resistance and through the laundry and a thermostat sensitive to the temperature of the air leaving the laundry and whose opening stops the supply of the heating resistor. This dryer comprises an interruption means (19, 21) preventing a new supply of the resistance (23, 26) after the first opening of the thermostat (10, 11, 12). The interrupting means comprises for example a thermostat (19), which is not subjected to the current of hot air coming out of the laundry but is heated by an electric resistance (21). The latter is supplied after opening the detection thermostat (10, 11, 12) sensitive to the temperature of the air leaving the laundry.

Description

41-

SECURITY CLOTHES

  The invention relates to a tumble dryer.

  Tumble dryers are usually automatic devices The automatic shut-off function can be controlled either by means of a timer or by measuring the residual humidity in the laundry. Timer devices are the simplest and least expensive They include a timer that interrupts the heating after a time determined by the user Because of the randomness attached to the choice of time, it is rare that the degree of drying is satisfactory, as laundry is generally

too wet or too dry.

  Tumble dryers whose control of the shutdown is carried out by measuring the degree of moisture remaining in the laundry do not exhibit this

  disadvantage But these devices are expensive.

  The invention relates to a tumble dryer which provides a satisfactory degree of drying without

  significant increase in the cost of the device.

  For this purpose, it uses the thermostat sensitive to the temperature of the air leaving the laundry which is generally provided in the tumble dryers and this thermostat is used not only for its safety function but also to control the degree of drying of the laundry In fact, in known tumble dryers, the thermostat does not prevent drying

excessive.

  Thus, the dryer, according to the invention, comprises an electric heating resistor, a timer programmer for regulating the operating time of the apparatus, a means such as a fan for circulating air on the resistor. and through the laundry, and a thermostat sensitive to the temperature of the air coming out of the laundry and whose opening

  causes the feeding of the drying resistor to stop.

  It is characterized in that it comprises a means of interruption to prevent a new supply of the resistance after the first opening of the thermostat With this arrangement, the drying is permanently interrupted when the thermostat has opened, the temperature at which s opens this thermostat representing the desired degree of drying On the other hand, in known tumble dryers, after cooling this thermostat, this

  the last closes, causing the drying to continue.

  The interruption means can be made inexpensively Preferably, it comprises a stop thermostat associated with an electrical heating resistor for heating the shutdown thermostat after opening the first (detection) thermostat. first thermostat remains permanently open to interrupt

  feeding the drying resistance.

  Whatever the realization of the means of interruption, the operation is satisfactory when the time displayed is greater than that required However, if the selected time is too short, drying

  stops before the desired degree of drying has been reached.

  But this is not really a disadvantage because it has been found that users tend to display a

time too important.

  In any case, the most serious disadvantage of conventional tumble dryers is the excessive drying at which

  it is more difficult to remedy than insufficient drying.

  When the dryer is of the rotating drum type, preferably the drum continues to rotate after the interruption of the supply of the drying resistor With this arrangement, the user knows in advance, by the trimming of the timer, the moment of stop of the drum; he can then take the clothes out of the machine. Thus the creasing is minimized, the immobility of the drum being one of the main causes of

crumpling the linen.

  Thus, according to another of its aspects, the invention relates to a rotary tumble dryer of the timer type and electric heating resistance which is characterized in that it comprises a means for permanently stopping the supply of resistance. When the desired degree of drying has been reached, the drum continues to rotate until the desired time elapses by the user. Preferably, an air circulation means, such as a fan, also operates. until

the flow of this time.

  Advantageously, there is provided a signaling device to indicate to the user stopping drying before the lapse of time displayed It is preferable that this signaling is triggered after sufficient cooling of the laundry so that the user then knows that the laundry can

be extracted from the device.

  Other features and advantages of the invention

  will appear with the description of some of its modes of

  embodiment, the latter being carried out with reference to the attached drawings in which FIGS. 1, 2 and 3 are diagrams of three embodiments of resistance control circuits.

  dryer heaters according to the invention.

  In these embodiments, the tumble dryer is a rotating household appliance (not shown) rotating

  around an axis of horizontal preference.

  The example of Figure 1 relates to a dryer with three thermostats 10, 11 and 12 for drying three

  types of linen such as: "cotton", "synthetic" and "delicate".

  The three thermostats 10, 11 and 12 are arranged in

  the hot air outlet duct of the dryer (not shown).

  They are therefore sensitive to the temperature of the heated air having passed through the laundry The thermostat 10 opens for a temperature T1 = 700 Cenviron, the thermostat 11 opens for a temperature T 2 = 550 C, and the thermostat 12 opens for a

temperature T 3 = 450 Cenviron.

  Each of the thermostats 10, 11, 12 is in series with a switch respectively 13, 14 and 15 These switches 13, 14 and 15 constitute for example the contacts of a selector

at three positions.

  The thermostat-switch assemblies 10, 13 and 11, 14 are in parallel. The thermostats 10, 11 and 12 have a common terminal 16 while the switches 13 and 14

  also have a common terminal 17.

  The common terminal 16 to the thermostats 10, 11 and 12 is connected to a phase 18 of the electric power supply sector via, on the one hand, a thermostat

  additional 19, and on the other hand, a light 20.

  In addition, a large electrical resistance

  value 21 connects phase 18 to terminal 17.

  The terminal 17 is connected to the second phase 22 of the electric power supply sector via a heating resistor 23 in series with a switch or

  switch 24 of the timer of the dryer.

  Finally, the terminal 25 of the thermostat 12 which is opposite the terminal 16 is connected to the switch 15, and the opposite terminal of the latter is connected to the terminal 231 common to the resistor 23 and the contactor 24, via a

other resistance 26.

  The resistors 23 and 26 are subjected to a current of air generated by a fan (not shown), so that the air introduced into the drum of the dryer is heated when one and / or the other of the resistors 23, 26 is powered

in electrical energy.

  The thermostat 19, unlike the thermostats 10, 11 and 12, is not subjected to the hot air leaving the laundry but the heating produced by the electrical resistance 21 as it is

will see further.

  The timer has a timer (no

  shown) which controls the switch or switch 24.

The operation is as follows.

  The user actuates a selector (not shown) in three positions: "cotton", "synthetic" and "delicate" In the "cotton" position the switch automatically closes the switches 13 and 15 and leaves the switch open 14 In this way the heating of the air is carried out with the two resistors 23 and 26, that is to say that one obtains a heating at maximum power In the "synthetic" position, only the switch 14 is closed, and in the "delicate" position, the

  three switches 13, 14 and 15 remain open.

  Before starting the machine the user also sets the timer on a predetermined time after which the switch 24 will be opened Then it operates

  the start switch (not shown).

  For the drying of the cotton, the switches 13 and 15 being closed, the switch 14 open, the resistors 23 and 26 are supplied as long as the temperature T1 triggering the thermostat 10 has not been reached The thermostats 11 and 12 open before the thermostat 10 is open But, these thermostats have no influence on the supply of the resistors 23 and 26 In particular when the thermostat 12 is open, the electric current passes through the resistance 26 through the thermostats 19 and 10, the switch 13, the contact

  17 and the switch 15, then closed.

  Thus, for cotton drying, a maximum drying power is provided until the degree of

  desired drying is achieved by opening the thermostat 10.

  When the thermostats 19 and 10 and the switch 13 are closed, the resistor 21 is

  shorted and therefore has no effect on the thermostat 19.

  On the other hand, after opening the thermostat 10, the current flows through the resistor 21 of great value. This current heats up

  the thermostat 19, which causes its opening.

  The opening of the thermostat 19 prevents any subsequent supply of the resistors 23 and 26 Without this thermostat 19, the supply of these resistors would be carried out after effect In fact, after cutting off the supply of the resistors 23 and 26, the temperature of the air leaving the laundry G decreases and, as a result, the thermostat 10 closes; this closure would result, if the thermostat 19 was not open, a new supply of resistors 23 and 26 and thus additional drying as in conventional tumble dryers type timer. The thermostat 19 and the resistance 21, which are

  associated, prevent excessive drying of the laundry.

  The drum continues to run and the fan runs until the time displayed by the timer has reached

not passed.

  When the thermostat 10 opens, the current passes through the resistor 21 and the resistors 23 and 26 But, the current flowing through the resistors 23 and 26 is then too

low to perform drying.

  After the opening of the thermostat 19 and the new closing of the thermostat 10 a current can pass through the indicator light The illumination of the indicator light 20 therefore signals to the user that the resistors 23 and 26 are no longer powered and that the laundry has cooled down. This indicator light 20 remains on until the opening of the

switch 24.

  The thermostats 19 and 10 are adjusted so that once the resistor 21 is energized, the thermostat 19 opens in a time less than the time separating the power failure of the resistors 23 and 26 of the new closure.

of the thermostat 10.

  If the timer has been set to a time too short, that is to say, as the switch 24 opens before the thermostat 10 opens, the desired degree of drying will not be reached. inconvenience is less troublesome than overdrying and it is easy to

operate the device.

  Since the indicator light 20 comes on after a new closing of the thermostat 10, that is to say after sufficient cooling, this ignition indicates to the user that the laundry is dried and that it can be taken out of the oven. machine

  before the lapse of the time displayed.

  It can also be noted that the resistors 23 and 26 are no longer supplied after the chosen degree of drying has been reached, the user benefits from energy savings compared to a conventional tumble dryer and that without

  significant increase in the price of the device.

  When the selector is positioned for drying the synthetic type of laundry, the switch 14 is closed, and the

  switches 13 and 15 are open.

  The resistor 23 remains energized until the opening

  from the thermostat 11 to the temperature T 2.

  For the rest, the operation is the same as for

the drying of cotton type linen.

  In a variant for the drying of the synthetic type of laundry switches 14 and 15 are closed, which allows heating with the resistors 23 and 26 until the temperature T 2 is reached, opening the thermostat he. In the "delicate" position of the selector, the three switches 13, 14 and 15 remain open. Thus, for heating, only the resistor 23 intervenes and its power supply is interrupted when the thermostat 12 is open at the temperature T 3. For the rest the operation is analogous to

  that already described for drying cotton.

  As a further variant, the indicator light 20 is replaced by (or associated with) another signaling device, for example

sound type.

  In the example just described, the dryer allows a degree of drying for three types of

machine.

  It is clear that the invention is not limited to three types of laundry, and that this number can be increased or decreased by providing a number of thermostats sensitive to the temperature of the air leaving the laundry in a number equal to that of

types of linen.

  Moreover, for each type of laundry it is possible to provide several degrees of drying For this purpose, it suffices to affect two (or more) thermostats set at different temperatures corresponding to different degrees of drying. FIG. 2 is shown in a simplified manner

such an embodiment.

  In the air outlet duct having passed through the laundry are arranged the two thermostats 30 and 31 set to open at the respective temperatures T 1 and T 2, the temperature T 1 being the highest and thus corresponding to the

  most important degree of drying.

  The thermostat 30 is in series with a switch 32.

  Similarly, the thermostat 31 is in series with a switch 33.

  Furthermore, there is provided a heating resistor 23, a switch 24 actuated by the timer programmer, a thermostat 19 associated with a resistor 21 and a LED mounted as elements with the same reference numbers.

of Figure 1.

  The operation is similar to that already described in

relationship with Figure 1.

  The dryer shown in FIG.

  several drying stages for several types of laundry.

  In this example, as in the case of FIG. 2, there is a thermostat 30 opening at a temperature T1 in series with a switch 32, as well as a thermostat 31 opening at a temperature T 2 lower than the temperature. tl

in series with a switch 33.

  These thermostats 30 and 31 are intended for a first type of textile Two other thermostats 34 and 35 intended for another type of textile are also provided in the air outlet duct and open at temperatures respectively T 3

  and T 4, T 3 being greater than T 4.

  The thermostat 34 is in series with a switch 36 whose terminal 40 opposite the thermostat 34 is connected to the terminal 17 and to a terminal of the thermostat 35.

  switch 37 is arranged between the terminal 40 and the resistor 26.

  The operation is as follows: for a first type of textile and the highest degree of drying, the switches 32 and 37 are closed. The heating is then carried out via the resistors 23 and 26 until it is reached. the temperature T1 for which the thermostat

opens.

  For the lower degree of drying of the first type of textile, the switch 32 is open and the switches 33 and 37 are closed. The drying is carried out thanks to the resistors.

  23 and 26 up to the opening temperature T 2 of the thermostat 31.

  For the drying of the second type of textile with the highest degree of drying, the switches 32, 33 and 37 are open and the switch 36 is closed. The heating of the air is then carried out by the resistor 23 until reopening. of

  thermostat 34 at temperature T 3.

  For the drying of the second type of textile to the degree of

  least drying, all switches are open.

  The drying is carried out with the resistor 23 until the opening

  from the thermostat 35 to the temperature T 4.

  With an embodiment similar to that described in connection with FIG. 3, it is possible to provide for each type of laundry a single degree of drying, but one control corresponds to the full load and the other to the half load. For example, for the first type of laundry, the thermostat 30 is assigned to the

  full charge, and the thermostat 31 at half load.

Claims (10)

  1 Electric resistance heater dryer (23, 26) and timer programmer for setting the operating time, the dryer comprising means for circulating air on the resistance and through the laundry and a thermostat sensitive to the temperature of the air leaving the laundry and the opening of which causes the supply of the drying resistance to be stopped, characterized in that it comprises an interruption means (19, 21) for preventing a new supply of resistance after the first opening of the   thermostat (10, 11, 12; 30, 31, 34, 35).   2 tumble dryer according to claim 1, characterized in that the interruption means comprises a thermostat (19) for stopping associated with an electric heating resistor (21) for heating, to keep it open, this thermostat (19). ) after opening the sensing thermostat (10, 11, 12)   sensitive to the temperature of the air coming out of the laundry.   3 tumble dryer according to claim 1 or 2, characterized in that being of the drum type, the latter rotates   until the time set by the timer has elapsed.   4 tumble dryer according to one of claims 1 to 3,   characterized in that the means for circulating the air   operates until the time set by the timer has elapsed.   Dryer according to any one of   preceding claims characterized in that it comprises a   signaling device (20) for transmitting a signal after opening the temperature sensitive thermostat (10, 11, 12) air coming out of the laundry.   6 tumble dryer according to claim 5, characterized in that the signaling device (20) emits a signal when the temperature of the air leaving the laundry falls below a predetermined threshold, after the opening of the thermostat (10, 11, 12) of detection.   it 7 Tumble dryer according to claim 6, characterized in that the signaling device (20) emits a signal to   closing the thermostat sensitive to the air coming out of the laundry.   Dryer according to Claim 2, characterized in that the heating resistor (21) of the stop thermostat (19) is short circuited when this thermostat (19) and the detection thermostat (10, 11, 12) are closed. , and is in series with the heating resistor when any of these thermostats is open.   9 tumble dryer according to claims 2 and 5,   characterized in that the signaling device is in   parallel to the stop thermostat (19).   Device according to any one of   preceding claims, characterized in that it comprises   minus two sensing thermostats (10, 11, 12) sensitive to different temperatures.   Dryer according to claim 10, characterized in that the temperatures of the thermostats represent one of the following parameters: the degree of drying, the type of laundry or load.   12 tumble dryer according to claim 2, characterized in that the stop thermostat ensures the interruption before a   new closing of the sensing thermostat.   13 rotating tumble dryer comprising a timer and an electrical heating resistor, characterized in that it comprises means for definitively stopping the supply of the electrical resistance of the heating when the desired degree of drying has been reached, the drum continuing to   turn until the time set by the timer has elapsed.