Field of the invention
[0001] The present invention relates to a bed warmer. In particular, the present invention
relates to a bed warmer with a tissue that helps in removing the moisture and increasing
transpiration.
Background of the invention
[0002] The bed warmers, heating pads, heating mats and similar products generally referred
to herein with the term "bed warmer" are known since long time ago. Typically, they
comprise a power control unit and an operating unit electrically connected one each
other; these two units can be connected one each other in a permanent way or they
can be separate and electrically connectable. The operating unit generally comprises
a folding sheet and a linear heating element distributed inside the sheet and consisting
of one or more conductors, mostly with a serpentine-like shape, having a path such
as to promote the sheet folding. The heat is electrically produced by a Joule effect
in the conductors, and from here the heat is distributed in the sheet.
[0003] In this way, by activating the heating elements of such bed warmers, the user can
lie down in bed and can appreciate the heat emitted from it, particularly appreciated
in the cold winter time.
[0004] There are, inter alia, devices that allow a better efficiency and safety of such
bed warmers, that allow the user to adjust the desired temperature and to automatically
lower the temperature until the switch-off of the bed warmers in the case the temperature
reaches too high levels or in case of excessive use over time.
[0005] The Applicant has observed that these bed warmers, while being typically supplied
with an electrical power or temperature regulation, designed for a continuous use
at night, may generate an unpleasant situation when the user erroneously chooses a
too high temperature or when uses heavy blankets also when the bad warmer is off,
because sweating is created while sleeping and thus it generates a not comfortable
feeling.
[0006] Moreover, such bed warmers are single-season type devices, since their use is limited
to winter time, while during summer times they are not used because they do not have
a useful function to the user. In this case, the bed warmer should be kept in a safe
place until its new use in the next cold season.
[0007] It is known that the wool has a high moisture absorbing power, but it is expensive
and produces a heating effect to the body that is troublesome during summer time.
[0008] On the other hand, it is also known that the silk is particularly useful for its
softness, as well as flax is useful for its freshness and polyester for its durability.
However all of these materials, as well as cotton, have a relatively low moisture
absorption.
[0009] Therefore, the Applicant of the present invention has noticed the need to achieve
a bed warmer which is simple and cheap to be manufactured, convenient to use, and
which solves the above described technical problem related to the excessive sweating
while sleeping.
[0010] To overcome these problems, the Applicant has surprisingly found that by providing
such bed warmers with at least one side coated with an outer layer formed by a particular
fibre, they are able to create a natural ventilation on the part of the body that
is in direct contact or indirectly through a sheet with said outer layer, keeping
drier the skin and thus giving the user a pleasant freshness feeling.
Summary of the Invention
[0011] The present invention relates to a bed warmer as that one indicated in claim 1.
[0012] The Applicant of the present application has in fact surprisingly found that a bed
warmer that includes an operating unit that includes a casing (or blanket) and a heating
element distributed inside the casing, characterized in that said bed warmer also
comprises a layer covering at least one side of said operating units, said layer containing
at least one textile fibre having a transpiration value, according to the evaporative
resistance tests disclosed in EN 31092 standard, which represents an improvement of
at least 30% with respect to the transpiration value of cotton,
is able to allow to reduce the sweating emitted by the user while sleeping, especially
during the warmer months or in conditions wherein the bed warmer is set at a high
temperature.
[0013] In fact, thanks to the natural ventilation generated by such textile fibres, such
fibres are able to absorb a lot of moisture and to let it evaporate in a natural way,
providing a moisture exchange capacity that is much higher when compared to other
natural fibres, such as, cotton and wool. Thus, an enjoyable situation of pleasant
freshness is created by keeping drier the user's skin.
[0014] In this way, the advantage of being able to use a single device consisting of the
bed warmer of the present invention provided with a means for reducing the moisture
emitted from the wearer's body due to his sweating while sleeping is also obtained.
In fact, such a single device can be used throughout the year, both as a bed warmer
to heat the bed during the cold months, and as an element to cool the body during
the warmer months, wherein a greater user sweating occurs.
[0015] In the present invention, when reference is made to cotton and/or polyester, it is
meant, respectively, a reference to that kind of cotton and/or polyester typically
used in the bedding field, having the structure, texture, workmanship, fabric, wire
strands and other features adapted to obtain the typical cotton and/or polyester bed
sheets and similar accessories.
[0016] Preferably, said textile fibre has a transpiration value that is at least 150% the
one of cotton, according to the evaporative resistance tests disclosed in EN 31092
standard.
[0017] In this way, the moisture due to the user sweating, whose body produces about 0,4
litres of moisture, is greatly absorbed.
[0018] In a first embodiment, said textile fibre is a viscose fibre extracted from wood
pulp cellulose, especially from eucalyptus wood.
[0019] In this way, such a fibre results to be naturally hygienic and 100% biodegradable,
providing a particularly soft, direct contact with the skin, without irritating the
skin itself.
[0020] Preferably, said textile fibre extracted from the cellulose is provided with nano-fibrils.
[0021] In this way, being the nano-fibrils hydrophilic and highly flexible, they allow an
optimum moisture absorption with the best thermal properties.
[0022] Preferably, said nano-fibrils are homogeneously distributed within said textile fibre.
[0023] In this way a uniform moisture absorption distribution throughout the entire bed
warmer is obtained.
[0024] Preferably, said textile fibre is of the lyocel type (also called Tencel), which
is a fibre made from crushed cellulose dissolved in NMMO-monohydrate (N-methylmorpholine-N-oxide-monohydrate).
Such a type of fibre is commercially available under the registered trademark Tencel
R by Lenzing Ag, Austria.
[0025] The structure of such fibres ensures that any moisture released while sleeping is
immediately transported to the outer surface of the fabric, letting it immediately
evaporate. The fibre transpiration thus keeps the body always pleasantly cool and
dry.
[0026] In a second embodiment, said textile fibre is a yarn specially molded; more preferably,
the structure of said textile fibre comprises a plurality of microchannels in its
interior, for example 4 or 6 microchannels, which extend for the whole length of the
fibre.
[0027] In this way, through said micro-channels present in the fibre, the moisture released
during user sleeping is more rapidly transported towards the outer surface of the
layer to obtain a more rapid evaporation.
[0028] Preferably, said textile fibre of this second embodiment is provided with the Coolmax
R trademark by Invista
™, USA.
[0029] In any of these first and second embodiment of the textile fibre, preferably, said
outer layer containing the textile fibre is fixed to said operating unit comprising
said casing enclosing therein said heating element by means of sewing or quilting.
[0030] Preferably, said bed warmer is coated on both the upper side and the lower side by
said outer layer formed by said textile fibre.
[0031] Preferably, said bed warmer further comprises a power control electrically connectable
at one end to an electrical supply network and at the other side to said operating
unit.
[0032] Further characteristics and advantages of the present invention will become more
apparent from an examination of the following detailed description of the preferred
embodiments, but not exclusive, illustrated only by way of non-limiting example, with
the support of the accompanying drawings. In particular, in the drawings:
- Figure 1 is a schematic view of a bed warmer of the present invention, wherein the
heating element, the casing and the outer casing, separated one each other, are visible;
- Figure 2 shows a perspective view of a portion of the bed warmer of Figure 1, wherein
the heating element is placed inside the casing.
Detailed description
[0033] The following detailed description refers to particular embodiments of the bed warmer
of the present invention, without limiting the content.
[0034] Referring to Figures 1-2 an embodiment of the bed warmer 10 of the present invention
is described, intended to be supplied at an AC voltage, for example with a frequency
of 50 or 60 Hz.
[0035] The main elements that constitute the bed warmer 10 of the present invention are
shown in Figure 1, separated one each other, before being assembled together. In fact
the heating element 1, consisting of an electric wire coil, a blanket 2 that serves
as a casing for the insertion therein of the heating element 1, and the outer layer
3 that includes the textile fibre for the absorption moisture, to be applied to the
casing 2, are visible.
[0036] On the contrary, the housing 2 wherein the heating element 1 is inserted is shown
in Figure 2, at one end of which is arranged an outlet 4 for the connection to a cable
for the electricity network, so that the casing 2 and the heating element 1 constitute
all together the operating unit 400 of the bed warmer 10. The bed warmer 10 also comprises
a power supply control unit 300 (contained in a plastic housing 209) which is electrically
connectable, on one side, to a power supply network and, on the other side, to such
an outlet 4 of the operating unit 400 by means of an interconnecting cable 207, in
conformity with the international codes H03VV-F 2 X 0.50 mm
2 of the electrical cables and having for example a length of 60 cm.
[0037] The user, through the power supply control unit 300, can set various parameters related
to a better utilization of the bed warmer 10 by the user itself as, for example, the
desired temperature, duration of its operation, its turning off after a certain period
of time and other parameters related to time, temperature, absorbed and dissipated
energy.
Example 1 (first embodiment of the invention).
[0038] The outer layer 3 is substantially constituted by such a textile fibre of the Lyocell
type, marketed under the name 700-600 Tencel
R from Lenzing Ag, Austria, which is a modified viscose fibre, naturally hygienic,
extracted from the eucalyptus wood pulp cellulose, 100% biodegradable, having a smooth
and particularly soft surface. Such a fibre is made by nano fibrils, distributed in
a homogeneous and regular way as to allow an optimal moisture absorption and a constant
and homogeneous temperature on the whole contact surface of the user and, consequently,
a considerable reduction of the bacteria proliferation. In addition, this fibre has
neutral electrical properties, thus protecting the user's body from electrostatic
charges.
[0039] To complete the construction of the bed warmer 10 of the present invention, the outer
layer 3, comprising such a Lyocell type textile fibre, is fixed to the operating unit
400, constituted as mentioned above by the casing 2 which contains in its interior
the heating element 1 (Figure 2), so that the outer layer 3 completely covers the
side of the operating unit 400 facing the user (not shown in the figures). Such an
outer layer 3 may be fixed to the operating unit 400 for example by sewing or quilting.
[0040] In this way, once activated the bed warmer 10 through the power supply control unit
300, in case a high partially temperature setting is reached during the night, the
sweat emitted from the wearer's body while sleeping is rapidly absorbed from the textile
fibre contained in the outer layer 3 which allows to keep more dry the user's skin
and then to give the user a comfortable feeling while sleeping. In fact, thanks to
the natural ventilation generated by such textile fibres, such fibres are able to
absorb a lot of moisture and let it evaporate in a natural way, providing a very high
moisture exchange capability.
[0041] In addition, during warmer summer time, when it is not necessary to activate the
heating element of the bed warmers of the present invention, it is possible to continue
to use such a bed warmer. In fact, thanks to the fact that it is also provided with
the outer layer comprising the textile fibre for the sweating evaporation, it can
also be used exploiting a feature similar to that one of a mattress cover, so as to
supply the user a pleasant freshness feeling. Therefore, the bed warmer of the present
invention may be used throughout the year, instead of only in winter time as occurs
to known in the art bed warmers.
Example 2 (second embodiment of the invention).
[0042] The Example 2 is substantially equal to Example 1, the only difference being given
by the fact that in this case the outer layer 3 is substantially constituted by a
textile fibre marketed under the trade name Coolmax
R, available from Invista
™, USA. Such a fibre is made from a plurality of channels in its interior, about 4-6
channels, which allow a rapid transfer of moisture towards the outside to be evaporated.
Example 3 (comparison).
[0043] Comparison Example 3 is substantially equal to Example 1 of the invention, the only
difference being given by the fact that in this case the outer layer 3 consists substantially
of a typical cotton used in the bedding field.
Example 4 (comparison).
[0044] Comparison Example 4 is substantially equal to Example 1 of the invention, the only
difference being given by the fact that in this case the outer layer 3 consists substantially
of a typical polyester used in the bedding field.
Valuation of evaporating resistance of moisture vapour.
[0045] The various types of textile material used in Examples 1-4 were tested to assess
whether they were more or less breathable fabrics, measuring their evaporative resistance
of the moisture vapour (R
et) based on the test described in EN 31092 standard, which prescribes methods for the
determination of the thermal resistance and of the moisture vapour resistance, in
a steady state, of products such as textile materials, including multilayer assemblies
used for clothing, quilts, sleeping bags, seat and similar products. The use of this
measuring technique is limited to the maximum values of thermal resistance and moisture
vapour resistance which depend on the size and construction of the device (for example,
respectively 2m
2.K/W and 700 m
2Pa/W for the minimum specifications of the device treated in the present international
standard). The lower is the resistance, the more the fabric lets the water vapour
generated by the active body to be dispersed, the more it is breathable.
[0046] By setting the temperature of the measuring unit and of the air at 35 °C, with a
relative humidity R.H. of 40%, as indicated at point 7.4 of the above mentioned standard,
after 3 hours from the start of the test, the R
et value is obtained for each of the textile fibre used in Examples 1 and 2 of the invention
and in the Comparison Examples 3 and 4. The obtained values are reported in the following
Table 1.
Tabella 1
| Textile fibre |
Example |
Ret value |
| TencelR |
1 (invention) |
85 |
| CoolmaxR |
2 (invention) |
90 |
| cotton |
3 (comparison) |
130 |
| polyester |
4 (comparison) |
150 |
[0047] From this table it is clear that the Tencel
R and Coolmax
R textile fibres used, respectively, in bed warmers of the invention shown in Examples
1 and 2, showed an improvement in transpirability of at least 30% with respect to
that one of cotton, and even greater (at least 50%) than that one of polyester.
[0048] In fact, considering as indicated above that the lower is the transpiration value,
the higher is the humidity absorbed by the tested materials, having measured the transpiration
value (R
et) of the cotton (Comparison Example 3) as being equal to 130, the theoretical transpiration
value R
et (
x) of a material X (different from cotton) showing an improvement in the transpiration
value of 30% with respect to the transpiration value R
et (cotton) of the cotton is of about 91, as indicated by the formula:

[0049] Thus, having measured the transpiration values for Tencel
R and Coolmax
R, respectively, equal to 85 and 90 (Inventive Examples 1 and 2), both of them being
thus lower than 91 (related to an improvement of 30% with respect to cotton), it follows
that each of the materials tested in Inventive Examples 1 and 2 showed an improvement
in the transpiration value of more than 30% when compared to the transpiration value
of the cotton.
[0050] Thus, these textile fibres have a much higher moisture exchange capacity even compared
to that one of other natural fibres, such as cotton.
[0051] The bed warmers of the present invention therefore showed an ideal microclimate for
a better quality of sleep, also with a reduced bacterial growth due to a reduced amount
of residual moisture on the wearer's skin.
[0052] Of course, to those skilled in the art will be evident many modifications and variations
of the preferred embodiments described above, still remaining within the scope of
the invention.
[0053] For example, in another embodiment, each of both sides of the operating unit 400,
therefore, both the one on the side facing the user and the one on the opposite side,
may be covered by such an outer layer 3 comprising such textile fibre.
[0054] Accordingly, the present invention is not limited to the described preferred embodiments,
illustrated only by way of example and not limitative, but is defined by the following
claims.
1. Bed warmer (10) comprising an operational unit (400) that includes a casing (2) and
a heating element (1) contained inside the casing (2), characterized in that said bed warmer (10) also comprises a layer (3) covering at least one side of said
operating unit (400), said layer (3) containing at least a textile fibre having a
transpiration value, according to the evaporative resistance tests disclosed in EN
31092 standard, which represents an improvement of at least 30% with respect to the
transpiration value of cotton.
2. Bed warmer (10) according to claim 1, wherein said textile fibre has a transpiration
value, according to the evaporative resistance tests disclosed in EN 31092 standard,
which represents an improvement of at least 50% with respect to the transpiration
value of cotton.
3. Bed warmer (10) according to claim 1 or 2, wherein said textile fibre is a viscose
fibre extracted from cellulose wood pulp.
4. Bed warmer (10) according to claim 3, wherein said textile fibre is produced from
crushed cellulose dissolved in NMMO-monohydrate (N-methylmorpholine-N-oxide-monohydrate).
5. Bed warmer (10) according to any one of the preceding claims, wherein said textile
fibre is provided with nano-fibrils.
6. Bed warmer (10) according to any one of the preceding claims, wherein said textile
fibre is of the lyocell type.
7. Bed warmer (10) according to claims 1 or 2, wherein said textile fibre comprises a
plurality of micro-channels in its interior, for example 4 or 6 micro-channels, extending
for the whole fibre length.
8. Bed warmer (10) according to claim 7, wherein said textile fibre is available under
the trademark Coolmax™.
9. Bed warmer (10) according to any one of the preceding claims, wherein both the top
side and the bottom side of said operating unit (14) of the bed warmer (10) are coated
by said layer (3) containing said textile fibre.
10. Bed warmer (10) according to any one of the preceding claims, wherein said bed warmer
(10) further comprises a power supply control unit (300) electrically connectable
on one side to an electrical supply network and on the other side to said operating
unit (400).