EP0603508A1 - Ironing machine with device for moistening the laundry - Google Patents

Abstract

Ironing machine with a steam device for moistening the ironing material, in which the water quantity fed to a steam generator (20) is matched to the evaporation capacity of the latter by a regulation dependent on steam pressure of the feed capacity of a water pump (17), the exciting coil (26) of which can be switched by a controller (23). A steam-quantity setting device for matching the steam quantity to different ironing material is provided. <IMAGE>

Description

The invention relates to an ironing machine according to the preamble of patent claim 1.

From US-PS 2 964 865 an ironing machine of this type is known, the steam device has an electrically heated steam boiler to be filled with water to be evaporated, which is connected via a steam outlet nozzle and a steam line to a steam pressure valve, which is a switch in the circuit of the heating device of the Steam boiler controls. Since the humidification of the ironing goods can only be started when the entire water supply in the steam boiler has been heated to the evaporation temperature and the steam pressure has reached a certain level, a relatively long waiting time must be accepted before ironing begins. The heater is then turned off. If the steam pressure falls below a certain level during the ironing process due to the consumption of steam, the switch is closed by the steam pressure valve and the heating device is thus switched on again until the water is heated up again for sufficient steam development and steam pressure.

It can be seen that this known system is not only relatively sluggish, but also that the installed heating power must be quite large in order to achieve the proper moistening of the items to be ironed. The switching of the heating device also requires a corresponding design of the consequently relatively expensive switch.

The amount of steam required for humidification cannot be easily determined with this device. Therefore, the steam pressure valve is connected by a steam line to a magnetically operated steam regulating valve which is controlled by the operator through a pedal-operated switch. Furthermore, a steam quantity regulating valve which can be adjusted by the operator is provided, which has two thermal lines via two steam lines Contact with the steam distributor pipes standing in the ironing recess, the steam outlet nozzles of which are directed against the incoming material to be ironed. The degree of humidification is therefore dependent on the estimate of the steam requirement by the operator and their reaction. In addition, the operator must also observe the water level in the steam boiler and supplement it in good time because the heating device would be damaged without a safety device in the event of a lack of water or dry running.

Another ironing machine with a steam device is known from DE-OS 40 14 197. The steam device comprises a water tank, a heat exchanger with supply and return lines, an electrically heatable, thermostatically controlled steam generator, which is immediately preceded by a siphon, which always contains a small amount of water, and the water from the siphon and the water tank by a switch controlling the ironing machine or one own steam switch switchable pump can be fed. Furthermore, the evaporator is followed by a water separator in which, on the one hand, non-evaporated entrained or condensed water is separated from the steam and returned to the water tank via a return line and the heat exchanger, and from which, on the other hand, the steam via a steam riser pipe to an in the infeed area of the ironing material, in thermal contact with the stirrer well standing steam distributor rail U-shaped cross-section is conducted, in which a longitudinally corrugated condensate distributor roller is freely rotatably supported, via which the incoming ironing material is moistened with the condensate which deposits on it.

The pump is a very simple and therefore very inexpensive self-priming diaphragm pump and forms the only actuator for the steam generation and delivery in this system, so that the use of steam quantity regulating devices by actuators such as solenoid valves, mechanical shut-off valves and pump regulating devices as well as the use of pressure vessels and safety devices and a delay-free because of the small volume of the steam generator and the constant supply of water in front of him and by the optional Switching the pump intermittent or continuous steam delivery is possible.

Due to the fluctuating diaphragm hardness, the quality of the excitation winding, the manufacturing tolerances and mains voltage fluctuations as well as the change in these parameters during operation, diaphragm pumps have considerable copy controls. In order to take these parameters into account, the pump must be designed for a certain minimum delivery rate, which in the worst case still delivers enough water to the evaporator, but usually supplies the evaporator with too much water. When there is more power, the water that is not required is boiled and even reaches a high percentage of unevaporated water in the water separator, from which it is returned to the water tank. During a long ironing operation with steam generation and water return, the heat exchanger can no longer cool the water to be returned to the water tank sufficiently, so that the table top of the machine which is arranged directly above the water tank heats up considerably.

A further disadvantage has been found that the condensate precipitation on the condensate distributor roller at the end of the steam riser line, that is to say in the middle of the distributor roller, is stronger than in the region of the ends. In this area the ironing material is therefore moistened more than in the area of the ends. The steam is guided to the ends of the distributor roll by the ironing material guided over the longitudinally grooved distributor roll and there is a considerable loss of steam.

It can be seen that in addition to the disadvantages shown, both the steam device according to US Pat. No. 2,964,865 and that according to DE-OS 40 14 197 are very expensive.

The invention has for its object to provide an ironing machine with a steam device, which with substantially reduced technical effort regardless of the existing sample dispersion of the pump with regard to the delivery rate, changes during the operating time and / or voltage fluctuations in the power supply Evaporation provided water evaporates without excess and is available as steam completely for steaming the ironing material.

According to the invention, this object is achieved by the features specified in the characterizing part of claim 1.

The construction specified in claim 2 is particularly simple in terms of construction, which also requires only low switching powers and thus a relatively cheap switch. A two-point controller is proposed as the controller.

In claim 4, a preferred arrangement for pump control is specified.

The measure according to claim 5 serves to adapt the amount of steam to different items to be ironed.

The solution according to the invention enables the use of a diaphragm pump (claim 6) which is inexpensive and whose flow rate fluctuates from specimen to specimen does not have a disadvantageous effect by regulating the water supply.

An embodiment of the invention is described below with reference to the accompanying drawings.

Fig. 1

eine schaubildliche Darstellung einer Bügelmaschine mit der vereinfacht dargestellten Dampfeinrichtung und

Fig. 2

einen Prinzipplan der Dampfeinrichtung.

It shows:

Fig. 1

a schematic representation of an ironing machine with the steam device shown in simplified form and

Fig. 2

a principle diagram of the steam device.

1 shows, the frame of the ironing machine consists of a base 1 with a vertical stand 2, on which a hollow table top 3 is arranged. On the table top 3, a support base 4, the heated bow trough 5 and a board 6 are attached. A steam distributor pipe 7 is located on the infeed side of the hanger 5 arranged, which has a number of steam outlet nozzles 8. On the table top 3, two support arms 9, 10 are attached. A pivot lever 11 is mounted on the support arm 9 and a pivot lever 12 is mounted on the support arm 10. The ironing roller 13 is rotatably mounted on the pivot levers 11, 12. On the pivot lever 12 is a hand lever 14 for lifting the ironing roller 13 from the bow trough 5, z. B. in the event of a power failure.

The essential components of the steam device are arranged in the hollow table top 3. These include a water tank 15 with a filler neck 16 at the highest point, so that no water escapes when the ironing unit is hinged down when the tank is full, a self-priming diaphragm pump 17 which passes through a removal line 18 to the water tank 15 and a hose line 19 with a steam generator 20 is connected, from which a steam riser 21 leads to the steam manifold 7. A further steam line 22 leads to a membrane steam pressure switch 23, which is preceded by a steam quantity adjusting device 24 arranged in the steam line 22 and whose normally open contact 25 switches the excitation coil 26 of the membrane pump 17 depending on the steam pressure.

As shown in the Prizipplan, Fig. 2, a switch 29 is provided in the power lines 27, 28 of the AC power connection, the contact 30 in the switched-on state, the power line 27 with a line 31 leading to the excitation coil 26 of the diaphragm pump 17 and its contact 32 Mains line 28 connects to a line 33 which is connected with the connection 34 to a line 35 coming from the excitation coil 26. A line 37 for the contact 25 of the diaphragm vapor pressure switch 23 is connected to the line 31 leading to the excitation coil 26 via a connection 36, and a line 40 connected to one side of a heating device 39 of the steam generator 20 is also connected via a connection 38. A line 41 is connected to the other side of the heating device 39 and can be connected to the line 35 by the contact 42 of a thermostat 43. A series resistor 44 and a diode 45 are arranged in line 35. Finally, the contact 25 of the membrane vapor pressure switch 23 is connected to the line 35 via a line 46, in which a resistor 47 is arranged, through a connection 48.

The diaphragm vapor pressure switch 23 forms, together with the resistors 44 and 47, a two-point controller for the delivery rate of the diaphragm pump 17 that switches depending on the vapor pressure.

As is known, the temperature of the bow trough 5 is monitored thermostatically, the control of the pressure gearing and the rotary drive of the bow roller 13 takes place in a known manner by actuating the rocker switch 49. Both are therefore not shown and described in more detail. In Fig. 1 only the preselector 50 for the temperature preselection of the bow trough 5 is shown.

How it works:

As is usual with ironing machines of this type, before starting the ironing work in the ironing machine shown in FIG. 1, the working temperature of the ironing trough 5, which can be preselected with the aid of the preselector 50, and the temperature of the steam generator 20 required for water evaporation must be reached after actuation of the steam switch 29 and monitored thermostatically will.

Since the circuit measures for fulfilling these conditions are not the subject of the invention, all details in the principle plan, FIG. 2, have been omitted.

If both of the above conditions are met, the pump 17, the excitation coil 26 sucks the contact 30, the lines 31, 35, the series resistor 44, the diode 45, the terminal 34, the line 33, the contact 32 and the mains line 28 is in voltage, in this switching state with 100% delivery capacity, via the extraction line 18 purified water from the water tank 15 and presses it via the hose line 19 into the heated steam generator 20, the heating device 39 of which via the mains line 27 Contact 30, line 31, connection 38, lines 40, 41, normally open contact 42 of thermostat 43, line 35, connection 34, line 33, contact 32 and power line 28 are connected to voltage.

The temperature of the evaporator 20 is kept at approximately 130 ° C. by the thermostat 43.

• der zugeführten Wassermenge, sofern die Wärmemenge des Dampferzeugers größer ist als die benötigte Wärmemenge zum Verdampfen des Wassers und
• dem Strömungswiderstand ins Dampfausgang (Querschnitt und Lägen der Dampfsteigleitung 21 sowie die Summe der Querschnitte der Dampfaustrittsdüsen 8 im Dampfverteilerrohr 7)

Bei einem Dampfdruck im Dampferzeuger 20 von ≦ 100 mbar ist das vorliegende System so ausgelegt, daß es quasi drucklos arbeitet.The delivery rate of the pump 17 and the evaporation capacity of the steam generator 20 are coordinated with one another in such a way that only as much water is pumped into the evaporator 20 as can be completely evaporated there.
The inflowing water is evaporated and creates a vapor overpressure in the evaporator space, the level of which depends on

• the amount of water supplied, provided that the amount of heat from the steam generator is greater than the amount of heat required to evaporate the water and
• the flow resistance into the steam outlet (cross section and positions of the steam riser line 21 and the sum of the cross sections of the steam outlet nozzles 8 in the steam distributor pipe 7)

At a steam pressure in the steam generator 20 of ≦ 100 mbar, the present system is designed so that it works virtually without pressure.

The steam flows from the steam generator 20 via the steam riser 21 into the steam distribution pipe 7 and escapes through the steam outlet nozzles 8, which are arranged so that the steam flows tangentially to the ironing roller 5 in front of it, so that the ironing material is moistened from the beginning and the steam the roller cover is not reached directly, but only indirectly via the ironing material, which greatly reduces the brown color of the roller cover.

The total cross section of the steam outlet nozzles 8 is selected so that a pressure of approximately 20 mbar is produced in the steam distributor pipe 7. This pressure is sufficient to achieve optimal steam distribution. In addition, the steam distribution pipe 7, as shown in FIG. 1, is thermally connected to the heated bow trough 5 in order to be able to re-evaporate coarse steam particles.

To regulate the steam generation, when a certain steam pressure is reached, steam flows via the steam line 22 and the steam quantity adjusting device 24, which can be actuated by hand to adapt to different items to be ironed, into the membrane pressure switch 23. Its normally open contact 25 closes and switches the resistor 47 via the line 37, the connection 36, the line 35, the connection 48 and the line 46 parallel to the excitation coil 26 of the pump 17th

As a result, the voltage at the excitation coil 26 drops and increases at the resistor 47. The delivery capacity of the pump 17 thus decreases. In the present version to about 40% of their performance. The steam pressure in the steam generator 21 drops with steam consumption and the membrane pressure switch 23 opens the normally open contact 25, so that the delivery rate of the pump 17 is again 100%. The switching difference (hysteresis) is matched to the physical properties of the steam generator 21 and can be influenced with the aid of the setting device 24.

It can be seen that with the present steam device of the ironing machine, regardless of mains voltage fluctuations and scattering of the pump output with relatively little technical effort, an optimal steam distribution depending on the need is achieved by the, albeit low, excess pressure in the system.

Claims (6)

Ironing machine with a device for moistening the items to be ironed, which has a steam generator, to which water to be evaporated can be supplied by a pump and which is connected via a steam line to a steam distribution pipe in the inlet area of the items to be ironed, characterized in that the steam generator (20) The amount of water that can be supplied can be regulated in a manner dependent on the steam pressure via the pump (17) in such a way that it does not exceed the evaporation capacity of the steam generator (20). Ironing machine according to claim 1, characterized in that for the steam pressure-dependent regulation of a water quantity supply to the steam generator (20) adapted to the evaporation capacity, the pump (17), the excitation coil (26) of which can be switched by a controller arranged in a steam line (22). Ironing machine according to claims 1 and 2, characterized in that the regulator is a two-point regulator with a membrane vapor pressure switch (23, 25). Ironing machine according to claim 3, characterized in that the excitation coil (26) of the pump (17), which is in a circuit with a series resistor (44) and a diode (45), has a resistance (47) through the diaphragm pressure switch (23,) when a desired vapor pressure is reached. 25) can be connected in parallel. Ironing machine according to Claims 1 to 4, characterized in that a steam quantity adjusting device (24) is connected upstream of the membrane steam pressure switch (23, 25). Ironing machine according to claims 1 to 5, characterized in that the pump (17) is a diaphragm pump.

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