Note: Descriptions are shown in the official language in which they were submitted.
2Z~,5~
Combination Conlpact l~icrowavr oven and Velltllator System
Background of the Invention
This invention relates to a compact, or space-saving
type microwave oven which incorporates a ventilator system
as well as a cooling system into a unitized structure.
Compact microwave ovens are quickly becoming popular
household items. A compact microwave oven is essentially a
microwave oven of a conventional type and its hood combined
into a unitized structure. It must therefore be installed
like the hood of an ordinary range, and this means that
compact microwave ovens are very frequently set above an
electric or gas range already installed on the floor and are
themselves installed by making use of a wall nearby, or by
directly attaching to such a wall, although this involves
both the danger of overheating the wall behind and the
disadvantage of exposing the microwave oven to the heat,
smoke, vapor, grease-carrying air, etc. from the heating
device beneath.
It is therefore an object of the present invention to
provide a space-saving type microwave oven with a ventilator
system incorporated into a unitized structure which is so
adapted that a uniform rate of exhaust air flow can be
obtained independently of the characteristics of the
external vent to which it is connected such as its length
and inner diameter, and the direction in which the exhaust
air must travel from the ventilator system to that vent.
It is another object of this invention to provide a
combination compact microwave oven with ventilator and
cooling systems so designed that relatively cool air
available in the vicinity be taken in.
It is a further object of this invention to provide a
combination compact microwave oven with ventilator and
cooling systems so designed that no extra unit is required
even if there is no external vent nearby and the exhaust gas
from the ventilator system must be discharged back into the
room.
It is still another object of the proselyte invention to
provide a combination compact microwave oven with ventilator
and cooling systems so designed that various heat-producing
elements are cooled by cooling air circulated in separate
channels.
Brief Description of the Draw nags
FIG. 1 is a perspective view of a compact microwave
lo oven embodying the present invention with its cabinet and
back panel removed to present a partially exploded view.
FIGS. 2, 3, 4 and 5 are respectively a front, back, top
and bottom view of the oven of FIG. 1.
FIGS. 6 and 7 are respectively a left side view of the
oven of FIG. 1 with and without the left-hand ventilation
duct removed.
FIGS. 8 and 9 are respectively a right side view of the
oven of FIG. 1 with and without the right-hand ventilation
duct removed.
FIGS. 10 and 11 are each a portion of FIG. 10 showing
how the ventilator motor can be connected to an external
exhaust vent, depending on the position of the vent with
respect to the oven.
Detailed Description of the Invention
In FIG. 1, there is shown a perspective view of a
compact microwave oven 10 according to -the present invention
with a cabinet, or outer housing 11 and a back attachment
panel 12 removed to show its interior arrangements. FIGS.
2-5, 7 and 9 show partially sectional views of the same oven
10 as seen respectively from the front, back, top! bottom,
left-hand side and right-hand side. FIGS. 6 and 8 are the
left- and right-hand side views with the ventilation ducts
removed to show the interior design. Like parts are
assigned like numerals while single arrows with numerals 1-4
and thick arrows indicate principal air movements.
27~5~
The oven 10 comprises a cooking chamber 15 which by
itself is of a conventional type having a rotatable mounted
turntable 16 inside, a control pane]. 18 next to the cooking
chamber 15 and lacing the front, a high voltage transformer
19 and a magnetron 20. The ventilator system of the oven,
or. that part of the oven 10 for removing hot, moist and
sometimes grease-laden air generated, for example, by
cooking on the range byway, comprises a ventilator motor 22
and centrifugal fans 23 which are driven by it and installed
lo on either side of it like its left and right wings. The
ventilator motor 22 with the centrifugal fans 23 on its
sides is positioned at the top, back edge of the oven 10.
The ventilator system further comprises a right-hand
ventilation duct 25 and a left-hand ventilation duct 26
which are nearly vertical air passages having exhaust gas
intake openings 27 in the base panel cover 28 and conducts
the exhaust gas from the heating device below to the
centrifugal fans 23. The ventilator unit combining the
ventilator motor 22 and the centrifugal fans 23 is so
designed that its orientation can be rotationally adjustable
. so that the outlet for exhaust gas from the ventilator unit
can be connected conveniently with an external exhaust vent
available nearby when the oven 10 is installed. FIG. 10
shows a situation where such connection is made to a vent
above the oven 10. FIG. 11 shows a situation where such
vent is behind the oven 10. If there is no external vent
available conveniently nearby, exhaust gas from the
ventilator unit must be recycled back into the same room.
for such situations, there is provided a charcoal filter 29
placed in the space above the cooking chamber 15 and below
the cabinet 11 which space is utilized as exhaust duct.
. As for the cooling system of the combination compact
oven 10, a cooling air intake 30 is provided behind the top
part of the control panel 18 because this is the region
where relatively cool air is generally available near the
oven 10 under typical working conditions with consideration
US
- given to the heat gellerated by the electric or gas range
underneath A propeller fan 32 is so disposed that the
cooling air from the intake 30 can be directly blown onto
the high voltage transformer 19 because it is usually the
component with the highest rate of temperature increase and
hence requires highest cooling efficiency. The transformer
19 is disposed inside a compartment 33 formed by a base
panel 35, top panel 36, rear panel 37, the magnetron 20, the
right-hand side panel of the cooking chamber 15 and the
right-hand ventilating duct 25. The propeller fan 32 sends
air from the intake 30 into this compartment 33 to increase
the pressure-inside and causes the air to leave the
compartment 33 by branching out into the following four
routes provided for cooling purposes. Route 1 is for
cooling the magnetron 20 and includes a magnetron air
discharge duct 43 through which air in Route 1 leaves the
oven 10. Route 2 is for removing from the inside surface of
the front door, or window, of the cooking chamber 15 the
moisture from the vapor generated therein. The partition
wall between the cooking chamber 15 and the compartment 33
is provided with apertures 34 through which cooling air
enters the cooking chamber 15. The air then leaves it
through a discharge duct 45. Air in Route 3 enters and
leaves from the gap between the rear panel 37 and the back
attachment panel 12 respectively through right-hand and
left-hand back openings Andy 48, and is discharged through
an cooling air discharge duct 50. Air in this route cools
the area of contact between the oven 10 and the wall on
which it may be attached. Air in Route 4 finally, passes
between the floor of the cooking chamber 15 and the base
panel 35 to cool the turntable motor 52 and is led outside
through the cooling air discharge duct 50.
A compact microwave oven according to this invention
has many important advantages. Firstly, since the
ventilator unit with a motor and centrifugal fans can be
adjustable rotated at the time of installation to change the
US
direction of dazzler, tile noLI~al increase in pressure loss
inside the vent can be reduced and a uniform rate of
discharge ventilation capacity) can be obtained regardless
of the manner of installation, or whether the discharge is
made vertically as shown in FIG. 10 or horizontally as shown
in FIG. 11. Secondly, if there is no external vent
available in the room, the exhaust gas from the range below
is pushed by the centrifugal fans 23 and is passed through
a filter 29 before it is discharged. This obviates the need
lo for the installation of a separate filtering unit. Since
the ventilator unit is at an elevated location with respect
to the cooking chamber 15, a large portion of the space
above the cooking chamber 15 and below the cabinet 11 can be
utilized as exhaust duct. This further obviates the need
for an extra duct for forcing air to pass through the filter
I contributing to the reduction in the total size of the
oven 15. Thirdly, the cooling system is designed for
improved efficiency. The cooling air intake 30 is
advantageously located where relatively cool air is
available. Fourthly, the cooling effort is concentrated on
the transformer 19 which heats up at the fastest rate.
Fifthly, cooling air in the compartment 33 is immediately
branched into independent routes to cool different areas and
components of the oven. This enables a structure with fewer
ducts and improves the overall cooling efficiency.
This invention has been described above in terms of
only one embodiment but the description above is to be
considered as illustrative rather than as limiting and this
invention is accordingly to be broadly construed. For
example, the dimensions and shapes of individual components
need not be exactly as illustrated, nor are the numbers of
apertures at various openings required to be the same as
those shown in the drawings. The filter 29 need not be of
charcoal type. The scope of this invention is limited only
by the following claims.
