Abstrict
An electric heater includes a metal plate, an insulating plate,
and an electrothermal film thermally plated on a lower surface of
the insulating plate. The electrothermal film generates high temperature,
which is then transmitted through the insulating plate to the metal
plate. Then the metal plate is heated up to high temperature for
use. Then the electric heater is effective, quite safe to use, and
adaptable for various electric appliances.
Claims
What is claimed is:
1. An electric heater comprising: a metal plate made of material
possessing high heat conductive coefficient, an insulating plate
fixed under said metal plate, said insulating plate made of electrically
insulating material, an electrothermal film thermally plated on
a lower surface of said insulating plate, said electrothermal film
generating high temperature, said high temperature transmitting
through said insulating plate to said metal plate, which is then
heated up to high temperature to be used by various electric appliances.
2. The electric heater as claimed in claim 1, wherein said metal
plate and said insulating plate are boned together by means of glue
conductive to heat.
3. The electric heater as claimed in claim 1, wherein said metal
plate is additionally provided with plural positioning members fixed
under the lower surface for keeping said insulating plate in position
so that both said metal plate and said insulating plate are fixed
quite firmly together.
4. The electric heater as claimed in claim 1, wherein a temperature
sensor and a temperature fuse are additionally added on a lower
surface of the metal plate so as to control the proper temperature
of said electric heater.
Description FIELD OF THE INVENTION
[0001] This invention relates to an electric heater, particularly
to one having a metal plate with the best heat conducting property
for enhancing heat conductivity and stroke-enduring characteristics.
Then the electric heater can prevent damage of its surface to result
in risks possibly caused by water or electricity leaking.
BACKGROUND OF THE INVENTION
[0002] One of conventional electric heaters disclosed in Taiwan
patent of a publicized number. 301523 titled "Electric heater"
has a body made of micro-crystal plane glass, and an electrothermal
film coated on a lower surface of the micro-crystal plane glass,
for generating high heat. This conventional electric heater has
a disadvantage of easy damage of the micro-crystal plane glass caused
by external force to result in risks of water or electricity leaking,
[0003] Another conventional electric heater disclosed in Taiwan
patent of a publicized number 319373 titled "Electric water
heater with an electrothermal film" has a hollow housing and
a heating chamber made of insulating material in the housing, and
a heat generating film for heating up the heating chamber. The insulating
material of the heating chamber is also micro-crystal plane glass,
having the same problem and disadvantage of the above patent No.
301523.
[0004] Another conventional electric heater disclosed in Taiwan
patent of a publicized number 509453 titled "Electric heating
disc" has a heat-conducting disc, a heat generating film piece,
heat insulating cotton; and a shell. The high heat generated by
the heat generating film piece is transmitted to the heat-conducting
disc. The heat generating film piece is a heat-generating tube or
piece, indirectly heating the heat-conducting disc, so its heat
transmission is comparatively bad.
[0005] A last conventional electric heater disclosed in Taiwan
patent of a publicized number 427500 titled "Heat generating
plate for an electric heater" has a heat generating plate made
of a porcelain plate, a glass plate and a steel plate coated with
an enamel layer. This conventional electric heater also has the
same problem of inferior heat transmission.
SUMMARY OF THE INVENTION
[0006] The purpose of the invention is to offer an electric heater
provided with a reinforced heating transmitting surface so as to
be used with substantial safety.
[0007] One feature of the invention is a metal plate used as a
damage-resisting and high heat transmitting means, and an insulating
plate located under the metal plate, which has its lower surface
formed with a electrothermal film. Then the electrothermal film
generates high heat to be transmitted through the insulating plate
and then to the metal plate.
[0008] Another feature of the invention is the metal plate adhered
firmly with the insulating plate with heat conducting glue.
[0009] Another feature of the invention is positioning members
provided under the metal plate for firmly fixing the insulating
plate.
[0010] One more feature of the invention is a temperature sensor
and a temperature fuse for controlling the temperature of the heater.
BRIEF DESCRIPTION OF DRAWINGS
[0011] This invention will be better understood by referring to
the accompanying drawings, wherein:
[0012] FIG. 1 is a cross-sectional view of a first embodiment of
an electric heater in the present invention;
[0013] FIG. 2 is a magnified cross-sectional view of a part marked
(A) in FIG. 1;
[0014] FIG. 3 is a cross-sectional view of a second embodiment
of an electric heater in the present invention;
[0015] FIG. 4 is a magnified cross-sectional view of a part marked
(B) in FIG. 3;
[0016] FIG. 5 is a cross-sectional view of a third embodiment of
an electric heater in the present invention;
[0017] FIG. 6 is a magnified cross-sectional view of a part marked
(C) in FIG. 5;
[0018] FIG. 7 is a perspective view of an electric appliance using
the electric heater in the present invention;
[0019] FIG. 8 is a perspective view of another electric appliance
using the electric heater in the present invention;
[0020] FIG. 9 is a perspective view of another electric appliance
using the electric heater in the present invention; and, FIG. 10
is a perspective view of another electric appliance using the electric
heater in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] A first embodiment of an electric heater in the present
invention, as shown in FIGS. 1 and 2, includes a metal plate 1,
an insulating plate 2, and an electrothermal film 3 as main components.
[0022] The metal plate 1 may be made of steel, iron, aluminum,
aluminum alloy, or stainless steel possessing high heat transmitting
coefficient. Above all, steel may be the best for transmitting heat.
[0023] The insulating plate 2 to be provided under the metal plate
may be a micro-crystal plane glass, a porcelain plate, or a quartz
glass possessing electrically insulating property, which is a desirable
material.
[0024] The electrothermal film 3 coated on a lower surface of the
insulating plate 2 generates high heat to be transmitted through
the insulating plate 2 to the metal plate 1 so as to heat up the
metal plate 1, and then the electric heater can be utilized for
various electric appliances, as shown in FIGS. 7 to 10 so as to
supply the electric appliances with excellent heat transmitting
efficiency. Further, the metal plate 1 and the insulating plate
2 may be bonded together by means of heat conductive glue, but it
is not absolutely necessary.
[0025] A second embodiment of an electric heater in the invention
shown in FIGS. 3 and 4, has the same structure as the first one,
but additionally provided with plural positioning members 10 under
the metal plate 1 for keeping firmly the insulating plate 2 in position
with the metal plate 1.
[0026] A third embodiment of an electric heater in the invention
shown in FIGS. 5 and 6 has the same structure as the first one,
but additionally provided with a temperature sensor and a temperature
fuse 4 fixed under the metal plate 1 so that the temperature sensor
and the temperature fuse 4 can control the proper temperature of
the heater.
[0027] FIGS. 7 to 10 show various electric appliances using the
electric heater as their heat sources.
[0028] While the preferred embodiments of the invention have been
described above, it will be recognized and understood that various
modifications may be made therein and the appended claims are intended
to cover all such modifications that may fall within the spirit
and scope of the invention.
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