[0001] This patent refers to instant irons and it particularly concerns instant irons with
a vaporising chamber and steam generation on the top of the ironing plate.
[0002] The instant steam irons currently on the market have the ironing plate which also
generates steam, this means that cold water is sent into the vaporising chamber in
the plate by a pump and pipe coming from a tank which may be incorporated in the iron
or in a separate unit.
[0003] The ironing plates of these irons are formed by an aluminium base plate with electric
heating resistance, having a labyrinth shaping on the top and an upper covering counter-plate
which is fixed to the base plate with screws.
[0004] To obtain airtight steam pressure and heat resistance, a gasket composed of a section
of silicone rubber is fitted between the upper edges of the base plate and the covering
counter-plate.
[0005] In the internal chamber thus obtained, called the vaporising chamber, water is fed
which vaporises when it comes in contact with the plate heated by the electric heating
resistance, passes through the labyrinth channel and comes out as steam through the
holes provided on the bottom of the base plate.
[0006] These ironing plates have two fundamental negative aspects: rapid cooling of the
plate as soon as the water to be vaporised is sent in and limited heat transmission
between the base plate and the covering counter-plate which tends to cool rapidly,
being without any source of heat.
[0007] The silicone rubber gasket between the edges of the base plate and the covering counter-plate
acts as thermal insulation, with the result that the heat of the base plate is transmitted
only with great difficulty to the covering counter-plate, lowering the temperature
of the upper wall of the vaporising chamber and therefore requiring more powerful
heating resistances.
[0008] The water that is sent into the vaporising chamber is at environment temperature
and is therefore very cold in comparison with the plates, which are therefore subject
to a strong thermal shock with sudden and repeated lowering of their temperature.
Consequently, after a few instants, no steam is produced and water comes out of the
holes.
[0009] To overcome all the problems described above, a new vaporising plate has been designed
and made, suitable for any iron, with preheating of the water.
[0010] The new vaporising plate is composed mainly of a base plate, a special intermediate
gasket, a covering counter-plate with cradle-shaped channel in the upper part for
the pipe that preheats the water.
[0011] The base plate does not differ substantially from the known base plates.
[0012] The special gasket, fitted between the base plate and the covering counter-plate,
comprises a flat element composed of a layer of graphite coated on one side (bottom)
with an aluminium film. Both these materials are well-known heat conductors, the graphite
layer constitutes the adaptable sealing part of the gasket while the aluminium film,
facing towards the vaporising chamber, protects the graphite against water and steam.
[0013] On the upper surface of the covering counter-plate there is a cradle- or U-shaped
channel which starts from the hole where the water is sent into the vaporising chamber
and winds over all or part of the upper surface of said covering counter-plate.
[0014] This cradle-shaped channel holds and adheres to the water preheating pipe which,
besides being perfectly housed in this channel, receives at one end the water arriving
from the tank or from the pump, while the other end is connected to the hole in the
covering counter-plate, communicating with the vaporising chamber.
[0015] The preheating pipe may be made of any suitable material, preferably copper and/or
aluminium.
[0016] The new vaporising plate thus composed presents considerable advantages :
- the heat of the base plate is easily transmitted to the covering counter-plate through
the special graphite and aluminium gasket, at the same time guaranteeing airtight
steam pressure and an adequate temperature of the upper wall of the vaporising chamber;
- the heat of the covering counter-plate is transmitted, through the cradle-shaped channel,
to the preheating pipe; the water flowing through said preheating pipe is heated as
it passes so that it is already at a suitable temperature when it reaches the vaporising
chamber, avoiding thermal shock of the plates, avoiding the fall of temperature in
the vaporising chamber and allowing continuous steam production.
[0017] Consequently the heating resistance fitted in the base plate may have a lower power,
with consequent energy saving and longer life.
[0018] A practical embodiment of the invention is presented, as an example without limitation,
in the enclosed tables.
[0019] Figure 1 presents a vertical section of the various parts of the new vaporising plate
(P) and of the remaining part of an ordinary iron (F).
[0020] The vaporising plate (P) comprises the base plate (1) with heating resistance (1.1)
and steam outlet holes (1.2), the gasket (2), the counter-plate (3) with cradle-shaped
channel (3.1) for housing the preheating pipe (4).
[0021] Figure 2 presents a section of part of the gasket (2) in which are shown the layer
of graphite (2.1) and the aluminium film (2.2) of which the gasket (2) is composed.
[0022] Figure 3 presents an axonometric view of the various parts (1,2, 3, 4) of the new
vaporising plate (P) and of an ordinary iron (F).
[0023] These are sufficient indications to enable an expert person to realise the invention,
consequently, in the final application, variations may be made without prejudicing
the substance of the innovative concept.
[0024] The following claims are therefore made with reference to the above description and
to the enclosed table.
1. Vaporising plate for irons composed of a base plate and covering counter-plate wherein
a flat gasket is fitted between said base plate and upper counter-plate, composed
of a layer of graphite coupled with aluminium film, and where the side with the aluminium
film faces towards the vaporising chamber.
2. Vaporising plate for irons as in claim 1, wherein the flat gasket substantially covers
the whole surface of the covering counter-plate.
3. Vaporising plate for irons as in claims 1, 2, wherein the covering counter-plate presents,
on the upper surface, a cradle- or U-shaped channel, and where the water inlet pipe
is housed in said channel, receives at one end the water arriving from the tank or
from the pump while the other end is connected to the hole in the covering counter-plate
and communicating with the vaporising chamber.
4. Vaporising plate for irons as in claims 1, 2, wherein the U-shaped channel of the
upper counter-plate starts from the hole where the water is sent into the vaporising
chamber and winds over all or part of the upper surface of said covering counter-plate.