Information
-
Patent Grant
-
6433323
-
Patent Number
6,433,323
-
Date Filed
Tuesday, March 7, 200024 years ago
-
Date Issued
Tuesday, August 13, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Ostrolenk, Faber Gerb & Soffen, LLP
-
CPC
-
US Classifications
Field of Search
US
- 219 757
- 219 702
- 219 400
- 126 21 A
- 126 21 R
-
International Classifications
-
Abstract
The present invention relates to a damper apparatus for a microwave oven by which the production cost and the reliability of the operation can be obtained by simplifying the structure of a damper apparatus for controlling the air flow supplied into the cavity of a microwave oven, which comprises an air duct for guiding a cooling air from the machinery compartment of the microwave oven into the cavity; a damper rotatably installed in the air duct for opening or closing the air flow in the air duct; a motor which includes a shaft directly connected to the damper to drive the damper; and a micro switch installed at one side of the air duct for detecting the opening and closing states of the damper by contacting one side of the damper.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a damper apparatus for controlling the flow of air which is supplied into an oven cavity in a machinery compartment of a microwave oven and, more particularly, to a damper apparatus for a microwave oven in which the structure of the damper apparatus is simplified to thereby reduce the production cost and obtain the reliability of the operations at the same time.
2. Description of the Prior Art
A microwave oven is an apparatus in which microwave is generated by applying current, the thusly generated microwave is introduced into an oven cavity, a space for accepting a heating object, for thereby heating the heating object.
Such a microwave oven has various functions due to the diversification of required heating characteristics. For instance, a product having a heater for heating food at a higher temperature therein is developed.
The microwave oven having such a heater is advantageous because it can have more various heating characteristics compared to conventional microwave ovens, escaping from a single heating characteristic utilizing microwave.
That is, it is possible to heat food at a higher temperature and brown the surface of food using an electric heater.
And, the microwave oven forms an air flow for exhausting steam or smoke generated by heating, in the cavity which is a space for heating.
FIG. 1
is a perspective view illustrating a general microwave oven which is divided into a cavity (C), a space for heating food by a partition
11
, which is opened or closed by a door
12
, and a machinery compartment
10
which has a microwave generating unit for generating microwaves.
The machinery compartment
10
includes a high voltage transformer
13
for boosting a supplied current to a high voltage, a magnetron
14
for oscillating microwave using a high voltage supplied by the high voltage transformer
13
, a cooling assembly
20
for radiating the high voltage transformer
13
and the magnetron
14
which generate much heat when driving the microwave oven, an air duct
15
which allows a part of cooling air generated in the cooling assembly
20
to cool the high voltage transformer
13
and the magnetron
14
to thereafter introduce the same into the cavity (C).
Herein, the path through which the part of cooling air is introduced into the cavity will be described as follows.
The cooling air generated in the cooling assembly
20
is guided through the air duct
15
installed adjacent to the magnetron
14
, and introduced into the cavity (C) through a plurality of air vents(not shown) formed on the partition
11
which partitions between the cavity (C) and the machinery compartment
10
.
That is, the partition
11
corresponding to the inside of the air duct
15
has an inlet port including a plurality of air vents(not shown) formed thereon, and the cooling air guided through the air duct
15
is introduced into the cavity through the inlet port.
And, the thusly introduced cooling air is exhausted to the outside of the microwave oven through an outlet port(not shown) formed on the opposite wall of the cavity, along with steam or smoke generated in the cavity (C).
In the microwave oven having a heater(not shown) thus described, when heating food using the heater(not shown), the cavity (C) in which the food is placed has a very high temperature, and heat of such a high temperature gradually heats the food.
By such a heating operation using the heater, food is heated by itself, or at the same time using microwave oscillated by the magnetron
14
.
In the case that food has to be heated at a high temperature as described above, it is not preferred that the cooling air from the cooling assembly
20
is introduced into the cavity (C).
That is, when the cooling air of a low temperature is introduced into the cavity and exhausted to the outside, the loss of heat is actually large.
Thus, the cooling air of a low temperature must be selectively introduced into the cavity (C) through the air duct
15
. As an example of the above-described construction, U.S. Pat. No. 4,450,344 will be described as follows with reference to FIG.
2
.
FIG. 2
is a block diagram illustrating the construction of a conventional damper apparatus for a microwave oven. As shown therein, the cooling air from the cooling fan assembly
20
can be selectively introduced into the cavity (C) by allowing a damper
30
to open or close the inlet port
16
which is a path into the cavity (C).
More specifically, the damper apparatus includes a cam member
40
to which the rotation of a motor
41
is transferred; a damper link
31
which is eccentrically connected to the cam member
40
; a damper
30
for opening or closing the inlet port
16
in which one end
30
a
is connected to the damper link
31
, and the other end is rotatably connected to one side of the partition
11
; and a micro switch which is installed at one side of the cam member
40
for thereby detecting the rotation volume of the cam member
40
.
The operation mode of the thusly constructed damper apparatus is as follows. The rotation of the motor
41
is transferred to the cam member
40
for rotation purposes, the damper
30
is interlocked with the damper link
31
which is connected to the cam member
40
, thereby opening or closing the inlet port
16
, and the open state and the close state are detected by the micro switch
50
for sensing the rotation volume of cam member
40
However, the above-described damper apparatus has problems that the mechanical elements for transferring the rotation of the motor (M) to the damper
30
are complicated so that the production unit price is increased and the assembly characteristics are deteriorated.
In addition, since the micro switch
50
for detecting whether the damper opens or closes the inlet port
16
is constructed to contact the cam member
40
for thereby detecting the open and close states of the damper by sensing the rotation angle thereof, the micro switch
50
cannot directly detect the damper
30
. Thus, there arises another problem that it is difficult to detect the full-open state of the damper
30
due to the clearances between the complex elements or the combination of assembly allowances.
Furthermore, there is still another problem that because it is difficult for the damper to fully open or close the inlet port, a gap is generated and thus a cooling air is introduced.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a damper apparatus for a microwave oven in which a rotation shaft of a damper and a rotation shaft of a driving motor are formed in one united body in order to simplify the damper and its peripheral construction and control the damper accurately.
To achieve the above object, there is provided a damper apparatus for a microwave oven which includes an air duct for guiding a cooling air from the machinery compartment of the oven into the cavity; a damper rotatably installed in the air duct for opening or closing the flow of air in the air duct; a motor which includes a shaft directly connected to the damper to thereby drive the damper; and a micro switch installed at one side of the air duct for detecting the opening and closing states of the damper by contacting one side of the damper.
Additional advantages, objects and features of the invention will become more apparent from the description which follows.
BRIEF DESCRIPTION OF THE INVENTION
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1
is a perspective view illustrating a general microwave oven;
FIG. 2
is a block diagram illustrating the construction of a conventional damper apparatus for a microwave oven;
FIG. 3
is a schematic view illustrating the basic construction of a damper apparatus according to the present invention.
FIG. 4
is a block diagram illustrating the open-close operation of a damper apparatus according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of a damper apparatus for a microwave oven according to the present invention will be described as follows with reference to the accompanying drawings.
FIG. 3
is a schematic view illustrating the basic construction of a damper apparatus according to the present invention.
FIG. 4
is a plane view illustrating the open-close operation of a damper according to the present invention. Reference numeral
11
denotes a partition between a cavity (C) and a machinery compartment
10
, which is provided with an inlet port
16
formed of a plurality of air vents
16
a
in order to introduce air into the cavity (C).
As illustrated therein, the damper apparatus comprises an air duct
140
which is installed on the partition
11
in order to guide air to the inlet port
16
; a motor which is installed at the inside of the air duct
140
and has a rotation shaft
150
a
; a damper having a rotation shaft hole
110
into which the rotation shaft of the air duct
150
is inserted formed therein; and a position control unit
120
which is installed at one end of the damper
100
and controls the rotation of the damper
100
by contacting a micro switch
130
.
Herein, the damper
100
is formed into an anchor or fan shape, the rotation shaft hole
110
is formed at the center of the rotation of the damper
100
to thereby block air to the inlet port
16
by closing the inside of the air duct
140
, or introduce air to the inlet port
16
by opening the air duct
140
.
In addition, the rotation shaft
150
a
of the motor
150
is inserted into the rotation shaft hole
110
, whereby the rotation of the motor
150
is directly transferred to the damper
100
. The position control unit
120
formed at one end of the damper
100
is constructed to contact the micro switch
130
at a certain position by the rotation of the damper
100
.
The operation mode of the thusly constructed damper apparatus according to the present invention will be described as follows.
First, in
FIG. 4
, the condition shown by the solid lines is a condition, wherein since the damper
100
is opened, air is guided by the air duct
140
to be supplied into the cavity through the inlet port
16
.
In the case that food is heated in a microwave oven mostly using microwave in such a condition, because the microwave directly heats the food, there is no problem with directly heating the food, although the surrounding air temperature is decreased. Therefore, although a cold air is introduced into the cavity, there is no large difference in the heating state.
However, in the case that food is heated using a heater (not shown) individually installed, because the air temperature surrounding the food has to be heated at a very high temperature, the heat in the cavity (C) must not be exhausted to the outside. Therefore, the inlet port
16
has to be blocked using the damper
100
, thereby preventing the heat in the cavity (C) to run off.
As described above, in order to perform the operation of closing the inlet port
16
, when a close command is given by a micro processor (not shown) of the microwave oven, and thereby the rotation shaft
150
a
is rotated in a clockwise direction by driving the motor
150
, the damper
100
is rotated in the same direction.
And, when the position control unit
120
formed at one end of the damper
100
contacts the micro switch
130
, the rotation of the damper
100
is terminated so that the inlet port
16
is held at the closed condition as shown by the one-dot chain line in FIG.
4
.
Therefore, a signal that the position control unit
120
has become in contact with the micro switch
130
is outputted by the micro switch
130
, the micro processor of the microwave oven stops driving the motor
150
.
In such a condition, food is heated by the electric heater(not shown) installed in the microwave oven while the inside of the cavity (C) maintains at a high temperature without introducing or exhausting air.
Meanwhile, the operation for opening the inlet port
16
is accomplished in the reverse order of the operation for closing the inlet port
16
. Thus, the detailed description thereof is omitted.
The present invention thus described can be summarized that the motor
150
directly connects the damper
100
installed in the air duct
140
to thereby drive the same. It will obviously be suggestive of any derivation or modification from the spirit and scope desired therein by those who skilled in the arts.
For example, the position and design of the micro switch for controlling the operation of the motor
150
, or the position and shape of the position control unit
120
for operating the micro switch
130
can be varied in many ways.
The damper apparatus according to the present invention thus described has an advantage of simplifying the construction thereof, while improving the reliability of the operation.
Also, the apparatus has another advantage of providing the optimum heating condition by preventing the loss of heat in the cavity, and improving the heating characteristics of the microwave oven.
Claims
- 1. A damper apparatus for a microwave oven, comprising:an air duct for guiding cooling air from a machinery compartment of said microwave oven into an oven cavity; a damper rotatably installed in said air duct, for opening or closing the flow of air in the air duct; a motor which includes a shaft directly connected to said damper without any cam device to thereby rotate the damper; and a micro switch for detecting the opening and closing states of the damper by contacting one end of the damper.
- 2. The apparatus of claim 1, wherein said micro switch detects a closing state of the air duct when said damper is contacted to the micro switch and an opening state of the air duct when the damper is separated from the micro switch.
- 3. The apparatus of claim 1, wherein said air duct includes an opening through which the damper rotates, and said micro switch is mounted on one end of said opening.
- 4. The apparatus of claim 1, wherein said damper includes a rotation shaft hole for being connected to the shaft of the motor, and a damper portion which is fan or anchor shaped, and wherein the air duct has an opening in a wall thereof, the damper being rotatable by the motor so as to close the opening in the wall of the air duct in the opening state of the damper.
- 5. A damper apparatus for a microwave oven, comprising:an air duct for guiding cooling air from a machinery compartment of said microwave oven into an oven cavity and installed on one side wall of the oven cavity; a damper rotatably installed in said air duct, for opening or closing the flow of air in the air duct; a motor which includes a shaft directly connected to said damper without any cam device to thereby rotate the damper, said shaft being parallel to the side wall of the oven cavity; and a micro switch for detecting the opening and closing states of the damper by contacting one end of the damper.
Priority Claims (1)
Number |
Date |
Country |
Kind |
99-35944 |
Aug 1999 |
KR |
|
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4208572 |
Melgaard |
Jun 1980 |
A |
4307286 |
Guibert |
Dec 1981 |
A |
4448578 |
Brunt et al. |
May 1984 |
A |
4450344 |
Sakoda et al. |
May 1984 |
A |
Foreign Referenced Citations (4)
Number |
Date |
Country |
2-199789 |
Aug 1990 |
JP |
4-161725 |
Jun 1992 |
JP |
6-2860 |
Jan 1994 |
JP |
6-94243 |
Apr 1994 |
JP |