[0001] This invention relates to a device for thermally insulating a household electrical
appliance or a part thereof in which heat is developed, such as a cooking chamber
of an electric, gas or combination oven.
[0002] With particular reference to an oven of the aforesaid type, its cooking chamber is
generally insulated from the remaining parts of the appliance by being covered with
a usual body of insulation material having low thermal conductivity.
[0003] This arrangement has however various drawbacks.
[0004] In this respect, forming the covering using an insulating body can involve considerable
problems related to the handling of the body and its application to the usual structure
defining the cooking chamber.
[0005] In addition, solid insulation material has its own emittance, resulting in heating
of the external structure of the oven or the structure containing this latter if it
is built into a kitchen unit.
[0006] Moreover, covering a cooking chamber with a body of insulating material of the aforesaid
type involves considerable time and hence cost, which negatively affects the cost
of the final oven.
[0007] An object of the present invention is to provide a device for thermally insulating
a household electrical appliance or a part thereof, such as a cooking chamber of an
electric, gas or similar oven, which is of simple construction, reliable and light
in weight, and which can be easily fixed to the electrical appliance or the part thereof,
for example to the structure of said cooking chamber.
[0008] A further object is to provide a device of the said type which is easy to handle
and enables an insulation to be obtained having a level of characteristics which depends
on the heat generated in the electrical appliance or the part thereof, for example
in said cooking chamber.
[0009] A further object is to provide a device of the aforesaid type which is of low cost.
[0010] These and further objects which will be apparent to the expert of the art are attained
by a device for thermally insulating a household electrical appliance or a portion
thereof in which heat is generated or developed, such as a gas, electric or combination
oven or the usual cooking chamber thereof, said electrical appliance or its portion
being delimited by walls subjected to radiation as a result of said heat generation
or development, said walls having therefore to be thermally insulated, characterised
by comprising, disposed on each of said walls to be insulated, at least two mutually
parallel flat elements associated with and slightly spaced-apart from each other,
said flat elements defining between each other an interspace in which spacer members
are provided, said flat elements being of substantially smaller thickness than the
walls to be insulated and being formed at least partly of high reflectance material.
[0011] The present invention will be more apparent from the accompanying drawing, which
is provided by way of non-limiting example and in which:
Figure 1 is a partly exploded perspective view of a cooking chamber to which the device
of the invention is applied;
Figure 2 is an enlarged section on the line 2-2 of Figure 1; and
Figure 3 is an enlarged section on the line 3-3 of Figure 2.
[0012] Said figures show a cooking chamber 1 of an oven, such as an electric oven.
[0013] For greater clarity, the heating members (of known type) have been omitted from the
chamber 1.
[0014] Said cooking chamber is delimited by walls 2, 3, 4, 5 and 6 which define a usual
aperture 1A providing access to the chamber.
[0015] On one side 2A, 3A, 4A, 5A, 6A of the walls 2, 3, 4, 5 and 6, external to the camber
1, there positioned first flat elements of substantially smaller thickness than said
walls.
[0016] Said flat elements, in substantially sheet form, are constructed of material of high
reflectance and low emittance, such as aluminium or like material. Alternatively,
one face 8 thereof, facing the chamber 1, is of aluminium or coated with a usual aluminium-based
coating.
[0017] Each element 7 can be coupled to a second flat element 10 which is spaced from and
parallel to the first, so as to define with this latter an interspace 11 in which
air is present.
[0018] Within the interspace there are also provided at least one spacer member 12 constructed
of insulating material such as glass wool. The members 12 are fixed in any known manner
(eg. glued) to that face 13 of the respective elements 7 opposite the face 8. Said
spacer member or members 12 are at least partly flexible, are of substantially cylindrical
shape, and cooperate with that face 15 of the second flat element 10 which faces the
chamber 1, which face can be aluminized if the element 10 is not of aluminium construction.
Said members 12 can thus be fixed to the face 15 itself.
[0019] Obviously the connection between the elements 7 and 10 can be formed in any known
manner, either by a direct connection between said elements or by known external retention
members (such as annular members which are made to embrace the flat elements when
these have been positioned about the cooking chamber 1), not shown.
[0020] To enable one or more further flat elements 20 constructed of high reflectance material
(shown by dashed lines in Figure 3) to be connected (for example by gluing), every
second flat element 10 comprises, on that face 16 opposite the face 15, at least one
spacer member 17 identical to said spacer members 12.
[0021] The chamber 1 is insulated by depositing the elements 7 on the chamber walls 2, 3,
4, 5 and 6 and fixing these elements to said walls by known means, such as screws
or by gluing with heat-resistant glue.
[0022] As the flat elements 7 are constructed in sheet form they can be very quickly, simply
and reliably applied to the walls 2, 3, 4, 5 and 6, so reducing the time required
for applying the desired insulation and the corresponding cost.
[0023] In one modification, the elements 7 are portions of the same sheet of high reflectance
material, surrounding the walls 2, 3, 4, 5 and 6 of the chamber 1 without discontinuity.
[0024] Having secured the flat elements 7 in the aforesaid manner, the second flat elements
10 are arranged on these latter or rather on the spacer members 12.
[0025] If these second elements are in the form of sheets they can be laid very simply.
[0026] The connection between the second flat elements 10 and first flat elements 7 is achieved
in the already described manner, for example via the members 12.
[0027] Again in this case the second elements 10 can be in the form of one sheet surrounding
the chamber 1. Advantageously, said sheet is the same as that which defines the elements
7 and wrapped a number of times about a itself, with spacer members 12 being interposed
between two parallel superposed layers (defining the elements 7 and 10).
[0028] The assembly obtained in this manner (elements 7 and 10 arranged parallel to and
spaced apart from each other, to define an interspace 11 in which air is present)
provides the chamber 1 with excellent insulation.
[0029] In this respect, because of the material used to form the elements 7 and 10 and the
presence of air between them, the heat generated within the chamber 1, which propagates
to the walls 2, 3, 4, 5 and 6 by conduction and would tend to disperse into the external
environment, is largely arrested and only a minimum quantity is dispersed into the
environment surrounding the chamber 1.
[0030] If even greater insulation of the cooking chamber 1 is desired, several flat elements
of high reflectance and low emittance are superposed until the required insulation
is achieved.
[0031] The device for insulating the cooking chamber 1 as described and as illustrated on
the accompanying figures is therefore of simple construction, of low cost and easy
to handle.
[0032] This device (comprising at least two flat elements 7 and 10 defining the interspace
11 containing the members 12) can be used to insulate any household electrical appliance
or part thereof in which heat is generated and which must therefore be insulated from
the external environment or from other parts of the electrical appliance.
1. A device for thermally insulating a household electrical appliance or a portion thereof
in which heat is generated or developed, such as a gas, electric or combination oven
or the usual cooking chamber thereof, said electrical appliance or its portion being
delimited by walls subjected to radiation as a result of said heat generation or development,
said walls having therefore to be thermally insulated, characterised by comprising,
disposed on each of said walls to be insulated (2, 3, 4, 5, 6), at least two mutually
parallel flat elements (7, 10) associated with and slightly spaced-apart from each
other, said flat elements (7, 10) defining between each other an interspace (11) in
which spacer members (12, 17) are provided, said flat elements (7, 10) being of substantially
smaller thickness than the walls to be insulated (2, 3, 4, 5, 6) and being formed
at least partly of high reflectance material.
2. A device as claimed in claim 1, characterised in that each flat element (7, 10) is
in the form of a sheet.
3. A device as claimed in claim 1, characterised in that each flat element (7, 10) is
formed of aluminium or an equivalent material.
4. A device as claimed in claim 1, characterised in that each flat element (7, 10) has
an aluminized surface or face (8, 15) facing the household electrical appliance or
its part (1).
5. A device as claimed in claims 1 and 5, characterised in that each spacer member (12,
17) is of substantially cylindrical shape and is advantageously fixed in any known
manner to that corresponding surface or face (13, 16) of a flat element (7, 10) which
is opposite to that facing the household electrical appliance or its part (1).
6. A device as claimed in claim 5, characterised in that each spacer member (12, 17)
is formed of glass wool.
7. A device as claimed in claim 1, characterised in that the parallel-arranged flat elements
(7, 10) are secured to each other by the spacer members (12) provided within the interspace
(11) defined by said elements (7, 10) and carried by one (7) of these latter.
8. A device as claimed in claim 7, characterised in that the connection between the flat
elements (7, 10) is advantageously achieved by gluing the spacer members (12) of one
of them to the other element.
9. A device as claimed in claim 1, characterised in that the constituent material of
the flat elements (7, 10) possesses low emittance.
10. A device as claimed in claim 1, characterised in that the flat elements (7, 10) are
parts of at least one and the same sheet of low emittance material surrounding the
cooking chamber (1).