U.S. patent number RE37,706 [Application Number 09/607,109] was granted by the patent office on 2002-05-21 for system of cooking or heating food products with microwaves and hot oil.
This patent grant is currently assigned to Trust c/o Alice H. Chung, trustee. Invention is credited to Jing-Yau Chung.
United States Patent |
RE37,706 |
Chung |
May 21, 2002 |
System of cooking or heating food products with microwaves and hot
oil
Abstract
The present invention provides a system for cooking and/or
heating a food product rapidly with the use of microwave and hot
oil heating, which are applied simultaneously during the entire or
partial period of the cooking and/or heating time. The food product
may be frozen prior to processing, and may consist of an outer
wrapper and an inner filling. It is desirable that after a
relatively short cooking and/or heating process, the outer wrapper
becomes crispy with a uniform golden-brown color while the inner
filling reaches a desired temperature.
Inventors: |
Chung; Jing-Yau (Houston,
TX) |
Assignee: |
Trust c/o Alice H. Chung,
trustee (Houston, TX)
|
Family
ID: |
23143312 |
Appl.
No.: |
09/607,109 |
Filed: |
June 29, 2000 |
PCT
Filed: |
August 28, 1995 |
PCT No.: |
PCT/US95/10831 |
371
Date: |
August 28, 1995 |
102(e)
Date: |
August 28, 1995 |
PCT
Pub. No.: |
WO96/07299 |
PCT
Pub. Date: |
March 07, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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296731 |
Aug 26, 1994 |
5520099 |
|
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Reissue of: |
507464 |
Aug 28, 1995 |
05771786 |
Jun 30, 1998 |
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Current U.S.
Class: |
99/404; 219/731;
426/242; 426/243; 426/438; 99/443C; 99/451; 99/DIG.14 |
Current CPC
Class: |
A47J
37/0623 (20130101); A47J 37/0664 (20130101); A47J
37/1228 (20130101); H05B 6/6411 (20130101); H05B
6/647 (20130101); H05B 6/782 (20130101); A23L
5/11 (20160801); A23L 5/15 (20160801); Y10S
99/14 (20130101) |
Current International
Class: |
H05B
6/80 (20060101); A47J 037/12 (); H05B 006/80 ();
A23L 003/00 () |
Field of
Search: |
;426/242,438,243,94,302,303,305 ;219/725,728,731,732,733
;99/404,409,418,451,DIG.14,443C,516,407 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3743922 |
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Jun 1989 |
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DE |
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52-70453 |
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Jun 1977 |
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JP |
|
Primary Examiner: Alexander; Reginald L.
Attorney, Agent or Firm: Oathout; Mark A.
Parent Case Text
This application is a continuation-in-part of U.S. application Ser.
No. 08/296,731 filed Aug. 26, 1994, issued as U.S. Pat. No.
5,520,099.
Claims
What is claimed is:
1. An improved rapid method for preparing a food product by
heating, .[.with the food product having an inner filling contained
in a wrapper (outer shell/skin) where it is desirable to cook
and/or heat the wrapper (outer shell/skin) with hot oil to obtain a
crispy wrapper (crust/skin) while in the mean time, to prepare the
food product by heating fully and uniformly the inner filling to a
desirable temperature and quality.]. comprising the steps of:
placing the food product in a heating chamber having a hot oil and
a microwave heating;
applying the hot oil to an entire out.[.side.]. .Iadd.er
.Iaddend.surface of .[.the wrapper (outer shell/skin) of.]. the
food product;
further preparing the food product in a microwave field; and
rotating .Iadd.by revolving and conveying .Iaddend.the food product
in the microwave field.
2. The improved rapid method for preparing a food product by
heating according to claim 1 wherein said step of heating the food
product in a microwave field is performed before said step of
applying the hot oil.
3. The improved rapid method for preparing a food product by
heating according to claim 1 wherein said step of heating the food
product in a microwave field is performed intermittently with said
step of applying the hot oil.
4. The improved rapid method for preparing a food product by
heating according to claim 1 wherein said step of applying the hot
oil comprises spraying the .[.wrapper (.]. outer .[.shell/skin).].
.Iadd.surface .Iaddend.with the hot oil.
5. An improved rapid method for preparing a food product by heating
.[.where it is desirable to heat the food product with an external
heating medium to obtain a desirable skin while in the meantime, to
heat fully and uniformly a core of the food product to a desirable
temperature and quality.]. comprising the steps of:
placing the food product in an oven having microwave heating;
applying .[.the.]. .Iadd.an .Iaddend.external heating medium to an
entire out.[.side.]. .Iadd.er .Iaddend.surface of the food
product;
simultaneous with said step of applying the external heating
medium, heating the food product in a microwave field;
moving fresh air into the oven while moving greasy air out of the
oven; and
removing the food product from the oven while the microwave field
continues to be emitted.
6. The improved rapid method for preparing a food product by
heating according to claim 5 further including the step of loading
the food product while the microwave field continues to be
emitted.
7. The improved rapid method for preparing a food product by
heating according to claim 5 further comprising the steps of moving
a heated food product out of the oven while draining the external
heating medium back into the oven.
8. The improved rapid method for preparing a food product by
heating according to claim 5 further including the steps of moving
a first compartment for containing the food product into a fully
powered microwave field and into the external heating medium while
simultaneously moving a second compartment for containing the food
product into an external portion of a pan and choking the microwave
field in the external portion of the pan.
9. The improved rapid method for preparing a food product by
heating according to claim 5 further including the steps of
containing the external heating medium in a unitary compartment for
loading, heating, draining and removing the food product.
10. An apparatus for preparing a food product by heating,
comprising:
an oven which defines an opening allowing access to the oven:
a microwave source/receiver mounted in the oven;
a means for externally heating the food product mounted in the oven
such that a heating medium heated by said means for externally
heating the food product will overlap a microwave field emitted by
the microwave source/receiver;
a means for moving the food product through the oven and hence
through the heating medium, the microwave field, and out of the
oven including an internal portion mounted inside the oven and an
external portion mounted outside the oven;
said external portion of the means for moving the food product
having a means for loading the food product and a means for
removing the food product; and
said oven having a gap for preventing the emission of the microwave
field.
11. The apparatus for preparing a food product by heating according
to claim 10 wherein said means for moving the food product through
the oven comprises a carrousel mounted in the oven and coupled to a
means for driving the carrousel.
12. The apparatus for preparing a food product by heating according
to claim 11 wherein said carrousel includes a hub coupled to the
means for driving the carrousel wherein said hub defines a
plurality of radial slots for receiving a plurality of arms each of
which are connected to said hub at one end by a hinge.
13. The apparatus for preparing a food product by heating according
to claim 10 wherein the means for externally heating the food
product and said means for moving the food product through the oven
are fixed together to form a unitary grease containment compartment
wherein said unitary grease containment compartment includes a
means for attaching said unitary grease containment compartment to
the oven, an entry allowing the passage of the microwave field and
a vent opening connected to a vent line mounted through the
oven.
14. The apparatus for preparing a food product by heating according
to claim 13 wherein the vent line includes a plurality of filters
and a blower mounted in the vent line.
15. The apparatus for preparing a food product by heating according
to claim 10 wherein said means for externally heating the food
product comprises a vat having a pool of oil.
16. The apparatus for preparing a food product by heating according
to claim 10 wherein the gap is in a frontwall of the oven.
17. The apparatus for preparing a food product by heating according
to claim 10 wherein the gap is defined by said means for removing
the food product.
18. The apparatus for preparing a food product by heating according
to claim 10 wherein the gap is defined by said means for loading
the food product.
19. The apparatus for preparing a food product by heating according
to claim 10 wherein said means for moving the food product through
the oven includes a means for draining the heating medium from the
food product and into the oven.
20. The apparatus for preparing a food product by heating according
to claim 10 wherein said external portion of said means for moving
the food product through the oven includes a hood hinged to the
oven for covering the external portion.
21. An improved rapid method for preparing a food product by
heating, .[.with the food product having an inner filling contained
in a wrapper (outer shell/skin) where it is desirable to cook
and/or heat the wrapper (outer shell/skin) with hot oil to obtain a
crispy wrapper (crust/skin) while in the mean time, to prepare the
food product by heating fully and uniformly the inner filling to a
desirable temperature and quality.]. comprising the steps of:
placing the food product in a heating chamber having a hot oil and
a microwave heating;
applying the hot oil to an entire out.[.side.]. .Iadd.er
.Iaddend.surface of .[.the wrapper (outer shell/skin) of.]. the
food product by spraying the .[.wrapper (.]. outer
.[.shell/skin).]. .Iadd.surface .Iaddend.with the hot oil; and
further preparing the food product in a microwave field.
Description
BACKGROUND OF THE INVENTION
Food manufacturers are constantly looking for a new improved method
of preparing foods. In particular, a rapid and efficient method
which also produces high quality foods is always desirable. Special
problems, however, are encountered by manufacturers when hot oil
heating (deep frying) is involved in cooking and/or heating food
products such as egg rolls, pizza rolls, fried taco rolls, fried
burritos, corn dogs or break fast rolls etc. which generally
consists of a wrapper (outer shell/skin) and an inner filling. Such
food products are difficult to cook and/or heat rapidly while at
the same time, yielding desirable crispiness of the wrapper (outer
shell/skin) and a high quality cooking and/or heating of the inner
filler. In general, if a relatively high temperature is applied in
the conventional deep-fry cooking and/or heating, the wrapper
(outer shell/skin) becomes overcooked and burnt before the inner
filling even reaches the desired temperature. This is particularly
true when the products are frozen prior to processing.
When heating the somewhat cylindrical food products mentioned above
by means of the conventional oil heating alone, it is known from
experience in the applicant's egg roll manufacturing plant that for
a product of one and one-half inches in diameter, the time required
to reach the core temperature of 160 degrees fahrenheit(F) from an
initial temperature of 50 degrees F. is about five minutes with the
oil temperature being maintained at 355 degrees F. If the same
product is frozen prior to processing, it becomes impossible to
obtain a satisfactory result by frying alone. For a thin and
uniform food product such as french fries, it does not constitute a
problem even if they are frozen prior to deep frying. But for the
same frozen egg roll mentioned above with an initial temperature of
15 degrees F. and the same frying temperature, the time required to
reach a core temperature of 160 degrees F. is about 10 minutes.
This core temperature level is required by the U.S. Department of
Agriculture meat and poultry inspection on food products such as
chicken egg rolls. At this frying time, however, the outer wrapper
of the egg roll becomes burnt long before the core temperature
reaches 160 degrees F. The present invention is a solution to the
problem of cooking and/or heating a frozen or non-frozen food
product in a relatively short time is to combine conventional oil
heating and microwave heating simultaneously during the entire or
partial period of the said cooking and/or heating time.
The microwave is widely used to cook and/or heat food products such
as frozen dinners or even frozen egg rolls mainly for its
relatively shorter heating time and for simplicity of operation. In
the case of heating an egg roll for example, the use of microwave
heating alone yields undesirable result. The microwave excites
water molecules of the inner filling, thus generating heat and
water vapor which causes the egg roll wrapper to become soggy. In
general, a food product having a wrapper (outer shell/skin) and an
inner filling with moisture cannot be cooked and/or heated
satisfactorily with microwaves alone, if it is desired to have a
crispy outer crust as the result of cooking and/or heating. This is
also true, even for a food product with uniform inner and outer
substances such as a french fry where a similar requirement,
namely, "a crispy outer layer" is sought after cooking and/or
heating.
The above argument supports the necessity of the present invention
for using both conventional oil heating and microwave heating for a
relatively rapid and better quality cooking and/or heating of a
food product consisting of a wrapper (outer shell/skin) and an
inner filling. It is apparent that a simultaneous application of
the two heating methods will not only further reduce cooking and/or
heating time, but also ensure the crispiness of the outer crust
after said cooking and/or heating. It should be noted that in the
case of cooking egg rolls (or other similar food products), it is
not desirable to use microwave cooking prior to a conventional oil
frying. An egg roll heated by microwaves yields a soggy egg roll
wrapper, a soggy egg roll wrapper breaks easily during deep frying.
The only workable method, in this case is to apply the two heating
methods simultaneously.
SUMMARY OF THE INVENTION
The present invention provides a system for cooking and/or heating
a frozen or a nonfrozen food product by means of combined microwave
and conventional oil heating methods which are applied
simultaneously during the entire or a partial cooking and/or
heating period providing: (a) a rapid cooking and/or heating time
and (b) a high quality fried product which gives a crispy outer
crust (wrapper) or outer skin.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an apparatus which may be used in the system of
the invention with portions of the apparatus being shown in
schematic form.
FIG. 2 is a cross-sectional elevational view of the system shown in
FIG. 1.
FIG. 3 is a view similar to FIG. 1 of another embodiment of the
invention.
FIG. 4 is an end-view of another embodiment of a roller which can
be used in the invention.
FIG. 5 is a view similar to FIG. 1 showing another embodiment of
the invention.
FIG. 6 is an elevational view of another embodiment of an apparatus
which can be used in the system of the invention.
FIG. 7 is an end view of the embodiment shown in FIG. 6.
FIG. 8 is an elevational view of another embodiment of an apparatus
which can be used in the system of the invention.
FIG. 9 is an end view of the embodiment shown in FIG. 8.
FIG. 10 is a view similar to FIG. 1 of another embodiment of the
invention.
FIG. 11 is a top view of a hood.
FIG. 12 is a top view of another embodiment of a hood.
FIG. 13 is a top view of another embodiment of a hood.
FIG. 14 illustrates a hub and arm which may be used in the
invention.
FIG. 15 illustrates a ring and arm which may be used with a hub in
the invention.
FIG. 16 is an elevational view of the embodiment shown in FIG. 10
with portions of the apparatus being shown in schematic form.
FIG. 17 is an elevational view of another embodiment of the
invention with portions of the apparatus being shown in schematic
form.
FIG. 18 is an elevational view of another embodiment of the
invention with portions of the apparatus being shown in schematic
form.
FIG. 19 is a top schematic view of another embodiment of the
invention.
FIG. 20 illustrates an arm and chain which may be used in the
embodiment of the invention shown in FIG. 19.
FIG. 21 is an elevational view of another embodiment of the
invention with portions of the apparatus being shown in schematic
form.
FIG. 22 is an elevational view of another embodiment of the
invention with portions of the apparatus being shown in schematic
form.
FIG. 23 illustrates the embodiment of the invention shown in FIG.
22 in an exploded view.
DETAIL DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, the system of the present invention
generally includes an oven body 10, a hot oil system 20 containing
hot oil 21, and a microwave source/receiver 30. The embodiment of
the invention may include a rotating tree 40 for moving the food
product 12 through the heating medium (oil) while turning the
product about its core axis.
The food product 12 is cooked and/or heated in the oven body (or
heating chamber) 10 which normally includes a door (not shown).
Prior to cooking and/or heating, the food product 12 comprises a
raw or a pre-cooked product which may be frozen, refrigerated or at
room temperature. The food product generally requires frying, which
includes products such as a french fry, a dough-based product such
as a donut, or a food product having an inner filling enclosed in
an outer shell such as an egg roll shown in FIG. 2 with the outer
wrapper 16. Other food products represented by 12 may include
similar products such as pizza rolls, spinach rolls, fried taco
rolls, fried burritos, corn dogs, breakfast rolls, fried pies and
pastries etc. As mentioned above, the food product 12 in a raw or
pre-cooked form is placed into the oven body 10 frozen,
refrigerated or at room temperature. It is desirable to cook and/or
heat the product rapidly and to obtain a high quality crispy outer
crust with a desirable uniform color while the inner filling
reaches a desirable temperature which, in the case of a meat or
poultry product, must comply with USDA regulations. The problems
encountered in processing such food products and some solutions to
the problems are discussed in U.S. Pat. No. 4,844,920 which was
issued to the present applicant on Jul. 4, 1989 and which is
intended to be incorporated herein.
A control system 14 which includes a temperature sensor 34 is
connected to the oven body 10, the hot oil system 20, the microwave
source/receiver 30 and the revolving tree 40 to regulate variables
such as cooking and/or heating time, temperature, rotating speed,
etc. The components to be used in such a control system are those
known to one having ordinary skill in the existing art. For
example, a temperature sensor 34 is located inside the oil
container 22 to register hot oil temperature for: (a) regulating
the hot oil temperature and (b) monitoring the temperature and
activating a safety shut-down in the event that the oil becomes
over heated. The hot oil system 20 includes an oil container 22.
The oil container 22 contains hot oil 21 which is heated either by
an external oil heater 28 or by the microwave or by both the oil
heater and the microwave. The oil container 22 is constructed in
such a way that the food product 12 can be fully or partially
submerged in the hot oil 21 while rotating horizontally through the
hot oil 21. An oil circulating line 24 having feed-throughs 25 and
26 connects the oil container 22 to the optional oil heater 28 with
oil filter 27 and oil pump 29 at the inlet and the outlet sides of
the oil heater 28 respectively. Other devices (not shown) may be
added to the oil circulating line 24 to reduce the FFA (free fatty
acids) in the oil.
The system of the present invention described above generally
operates with the oven body 10, the hot oil system 20 consisting of
the oil container 22 filled with hot oil 21 for the submersion of
the food product(s) 12 and a control system 14 which includes a
temperature sensor 34. It may also operate without the hot oil
system 20 where the oil is heated directly by the microwaves. The
system may also include an optional revolving tree 40. The
revolving tree 40 generally includes a journal 42 with a drive
shaft 43 which is driven by a variable speed motor 44. A hub 45 is
connected to the top end of drive shaft 43. Hub 45 supports rollers
46. The rollers 46 are preferably grouped in parallel pairs to
support the food product 12. By doing so, one roller of the said
pair is in the radial direction with respect to the shaft 43, while
the other is parallel to the aforementioned roller and in a
slightly off-radial direction. The roller in the radial direction
is driven by a gear in hub 45 or by the stationary oil container 22
and rotates about its own axis, while the roller in the off-radial
direction is driven by the food product 12 whose rotational motion
about its core axis is created by the roller in the radial
direction. The roller pairs 46, however, rotate as a group about
the drive shaft 43 to form a revolving tree 40. The rotation of the
roller pairs about their own axis may be omitted as an alternative
revolving tree system 40 in which the food product 12 is submerged
completely in the hot oil. The roller pairs 46 are preferably on a
horizontal plane in a "near-radial" direction with respect to the
shaft 43 in order to support and to rotate the food product 12. The
roller pairs 46 are generally spaced less than the diameter of the
food product. The rollers 46 should be at a height below the top of
the oil container 22 so that the food product 12 can be fully or
partially submerged in the hot oil. The rollers may be made or
coated with TEFLON or some other material which prevents the food
product 12 from sticking to the rollers. In fact a material such as
TEFLON is ideal to be used in the present system due to its
workability in the microwave field as well as its working
temperature range.
The microwave source/receiver 30 is connected anywhere within the
oven body 10 and it produces a microwave field depicted by the
field intensity contours 32. The microwave field 32 is preferably a
relatively high intensity field to shorten the cooking and/or
heating time.
Referring to FIG. 3, another embodiment of the invention which is
similar to that shown in FIG. 1 is represented. In addition to the
features shown in FIG. 1, the embodiment shown in FIG. 3 includes
an extension drive shaft 47 which is connected to the drive shaft
shown in FIG. 1. The upper end of the extension drive shaft 47
supports a plurality of poles 48 which are positioned one each
above the roller pairs 46. The poles 48 contain nozzles 49. A hot
oil line (not shown) runs through drive shaft 43 and extension
drive shaft 47 through poles 48 to the nozzles 49 for spraying hot
oil over the food product 12.
Referring to FIG. 4, if the rollers are to be driven about their
axis, it may be desirable to have a roller 46a having teeth 46b to
improve contact for turning the food product 12.
The embodiment of the invention shown in FIG. 5 is similar to that
shown in FIG. 1 except that in this embodiment, the revolving tree
140 includes arms 146 which extend from hub 45 on one end and
support receptacles 148 on the other end. Hot oil lines 145 run
from the journal 42 through the beams 146 and up to the upper end
of the receptacles 148 where they are attached to nozzles 149. The
receptacles 148 are upright (the longer axis is vertical) and open
at the top so that a food product 12 such as an egg roll can be
placed within the receptacle 148. In this embodiment the oil
container 22 catches any hot oil that spills over at the top of the
receptacles 148 as the receptacles 148 are rotated in the microwave
field 32.
Referring to FIGS. 6 and 7, an individualized food product heating
oven or chamber 60 which may be in any configuration is shown. In
this embodiment, a hot oil feed line 61 is introduced into a hot
oil manifold 62 which is connected to a plurality of parallel hot
oil feed lines 63. Each hot oil feed line 63 contains one or more
spray nozzles 64 as needed to uniformly direct hot oil to the food
product 67. The hot oil feed lines 63 are preferably connected to
the inside surface of the chamber 60 with each line placed as
needed in conjunction with nozzles 64 to uniformly direct hot oil
to the food product. A microwave source 65 is connected through the
chamber 60. A pair of mounting rods 66 are attached across the
lower end within the chamber 60 and they serve as a stand for the
food product 67. A hot oil evacuation line 68 is located on the
lower end of chamber 60 to drain hot oil 69.
The chamber 60 may be made of metal or some other material suitable
to confine the microwave field within the chamber. Food product 67
is inserted into the chamber 60 and is heated by microwaves
generated by a microwave emitter/receiver 65 and by hot oil 69.
Spray nozzles 64 and the pool of hot oil 69 direct hot oil around
the entire surface area of the food product 67. The system contains
a filter 27, heater 28, pump 29, and a control system 14.
Referring to FIGS. 8 and 9, another embodiment of the invention is
shown in which a perforated cylinder 70 is rotated within an oven
or shell 80. The shell 80 is stationary and contains a reservoir or
volume 82 of hot oil. The perforated cylinder 70 rotates about a
central axis 72. The central axis 72 is supported by bearings 73 in
shell 80 and is driven by motor 76. Perforated baskets 74 are
mounted within the perforated cylinder 70 such that when the
perforated cylinder 70 is rotated about an axis 72 the basket 74
will pass through the volume of hot oil 82. Baskets 74 are
constructed of a sufficient size to contain a food product 12 to be
heated by the hot oil 82 and microwave source 84.
The system of the present invention may be applied to serve a
freshly cooked and/or heated food product such as an egg roll to
customers. Prior to cooking and/or heating, the food product may be
in a raw or pre-cooked form and may be in a frozen or non-frozen
state. In this application, it is desirable to completely cook
and/or heat said food product in a short time in order to serve a
customer quickly. In order to achieve the rapid and full cooking
and/or heating of the food product, the hot oil should be heated to
a relatively high temperature range (about 350 to 500 degrees F.).
Control system 14 can include a safety shutoff feature to shut off
the heater 28 as well as the microwave power when the oil
temperature inside the microwave chamber reaches the high limit to
prevent a fire and/or burning of the food. The oil temperature
inside the apparatus is detected by a temperature sensor 34 located
in the hot oil container 21. In order to achieve a rapid and
thorough cooking and/or heating, it is preferred to utilize a
relatively high intensity microwave field within which the
object(s) to be cooked and/or heated are placed. A microwave field
is used simultaneously with the application of hot oil to heat the
food product 12 in less than a minute, obtaining a crispy (but not
burned, sometimes golden-brown) outer crust and to fully and
uniformly cook and/or heat the core or filling to a desired
temperature which must comply with USDA regulations in the case of
a meat or poultry product--for a meat product, the temperature must
reach 145 degrees F. or above, for a poultry product it must reach
160 degrees F. or above.
In some applications of the present system, it may be desirable to
apply hot oil either shortly before or after microwaving or to
stagger starting and stopping times of hot oil application and
microwaving. The system could also be constructed with more than
one microwave source/receiver to achieve a desired microwave
field.
In a recent experiment using the system of the present invention
shown in FIG. 1 without the revolving tree 40, a refrigerated raw
egg roll was successfully cooked in a much shorter time compared to
the time required in a conventional deep frying method adopted in
the applicant's egg roll manufacturing plant. This experiment
showed that the cooking time required by the applicant's current
conventional frying method was reduced by as much as sixty five
percent by using the system of the present invention with a
moderate microwave power (900 watts) and oil temperature (355
degrees F.). Moreover, if the applicant tried to use the
conventional cooking method, namely deep frying, to cook the same
raw egg roll from a frozen state, the egg roll would have to be
defrosted prior to cooking. Otherwise the egg roll wrapper would be
burnt before the egg roll core temperature reaches 160 degrees F.
which is required in this particular cooking procedure.
It may be advantageous to utilize an oven 100 which does not
incorporate a traditional microwave oven door (requiring a vertical
door to be opened and closed to insert and remove food products
which may interrupt cooking), to utilize a pan 130 which drains
excess oil away from the food product 12 to move fresh air in and
greasy air out of the oven, to contain the grease, and to readily
load and unload food products 12. Therefore, referring to FIGS. 10
and 16, an embodiment of the invention incorporating these
advantages is shown. This embodiment generally includes an oven
100, a vat 110, a vent 120, a pan 130, a chute 150, a motor 160, a
carrousel 170 and a cover 190.
The oven 100 includes walls 101, 102, 103 and 104, a base 106 and a
top 108. Front wall 101 includes an upper panel 101a and a lower
panel 101b which define a slot 105 therebetween. A food product 12
such as an eggroll must pass in and out of the oven 100 through
slot 105. In the case of an eggroll, the slot 105 is preferably
approximately two (2) inches in height and runs from wall 102 to
the wall 104.
A vat 110 is contained within the oven 100. The vat 110 contains a
pool of oil 112 (see FIG. 16). An oil circulation system (not
shown, but similar to the system shown in FIG. 1, reference numbers
24, 27, 28 and 29) is connected to the vat 110 for cleaning,
heating and circulating the oil 112.
Vent 120 may be connected to the oven 100 through the top 108 of
the oven 100. Vent 120 preferably includes a grease filter system
(not shown) and a blower (not shown).
A pan 130 is connected to the oven 100 through slot 105. The pan
130 includes an internal portion 132 and an external portion 134.
The internal portion 132 of the pan 130 includes a bottom 136, a
peripheral sidewall 138 and a screen 139 (which is connected to the
sidewall 138 to cover the internal portion 132 of the pan 130). The
internal bottom 136 of the pan 130 is preferably planar, semi
circular and slanted or inclined at an angle oblique to the
horizontal. The angle of the slant may vary but as shown in FIGS.
10 and 16 the slant is at an angle of approximately forty-five (45)
degrees from the horizontal.
The external portion 134 of the pan 130 is preferably planar, semi
circular and includes a bottom 140 and a peripheral sidewall 142.
The external bottom 140 of the pan 130 is also preferably slanted
or inclined at an angle oblique to the horizontal. The angle of
this slant may also vary but as shown in FIGS. 10 and 16 the slant
is at an angle of approximately five (5) degrees from the
horizontal. The external bottom 140 of the pan 130 may include an
opening 144 near the perimeter of the external bottom 140. The
opening 144 should be greater than the length and the diameter of
the food product 12.
A chute 150 is connected to the external bottom 140 of the pan 130
directly under the opening 144. The chute 150 includes arcuate
sidewalls 152 and 153, an arcuate top 154 and an arcuate bottom
155. A hinge 157 connects a one-way door 156 to the top 154 and
within the chute 150. A hinge 159 connects a one-way door 158 to
the top 154 and within the chute 150. The doors 156 and 158 should
be spaced apart by a distance greater than the diameter of the food
product 12. Gaps are defined between the perimeters of the doors
156 and 158 and the inner dimensions of the chute 150. The gaps
should be about one-eighth of an inch to allow air to be sucked
through the chute 150, into the pan 130, into the oven 100 and out
through the vent 120.
A motor 160 is coupled to a shaft 162. Shaft 162 is coupled to a
carrousel 170.
Carrousel 170, generally includes a hub 172 and upright arms 174.
The hub 172 is coupled to the shaft 162. The arms 174 are hinged or
connected to the hub 172.
One embodiment of the carrousel 170 is shown in FIG. 14. In this
embodiment, the hub 172 has a central slot 176 for coupling the hub
172 to shaft 162. The hub 172 also includes a plurality of radial
slots 178 (only one (1) is shown in FIG. 14 for sake of
simplicity). The radial slot 178 is adapted for receiving the arm
174 while allowing the arm 174 to rotate vertically. The end of the
arm 174 may be shaped accordingly to allow the arm 174 to rotate a
desirable number of degrees as dictated by the incline of the pan
130. A hinge 180 connects the hub 172 to the arms 174. Hinge 180
comprises a groove 182 in the hub 172, a hole 184 through arm 174
and a pin 186 which passes through the hole 184 and is seated in
the groove 182. Referring to FIG. 15, portions of another
embodiment of the hub 172 are shown. In this embodiment the hinge
180a comprises an annular groove (not shown) in the top of the hub
(not shown), a notch 187 in the top of arm 174 and a ring 188 which
seats in the annular groove and in the notch 187. The vertical
dimension of the arm 174 is preferably only slightly greater than
the vertical dimension of the food product 12 and only slightly
less than the vertical dimension of the slot 105 in front wall 101.
In the case where the food product 12 is an eggroll, the height of
the arm 174 should be about one (1) inch. A protuberance 175 may be
attached to the side of arm 174 between the ends of the arm 174 to
keep or maintain the food product at the periphery of the carrousel
170.
Referring back to FIG. 10, a hood 190 for covering the external
portion 134 of the pan 130 is shown. Hood 190 is hinged to the
frontwall 101. The hood 190 is preferably flat, semi circular, and
includes a lip 192. Two (2) switches (a primary and a back-up, both
not shown) in a microwave circuit (not shown) are mounted between
the interface of the hood 190 and the frontwall 101 (or sidewall
142).
Referring to FIGS. 11, 12 and 13, other embodiments of the hood 190
are shown. The hood 190a shown in FIG. 11 includes a cutout 191
which will be located above the periphery of the carrousel 170 when
the hood 190a is closed. The dimensions of the cutout 191 should be
greater than the dimensions of the food product 12. The food
product 12 can be automatically fed into the pan 130 through the
cutout 191. A chute (not shown but similar to the chute 150 having
double doors) can be mounted on the hood 190a over the cutout 191
for automatically feeding food products 12 while preventing the
escape of microwaves. The hood 190b shown in FIG. 12 is made of a
screen material 194. The screen material 194 incorporates a fine
mesh to prevent microwaves from escaping through the screen 194
while allowing air to pass. The hood 190c shown in FIG. 13 contains
a portion 195 which remains closed and a portion 196 which may be
opened. Portion 196 is connected by a hinge 197 to the frontwall
101 allowing access only to a quarter circle of the carrousel
170.
In operation, the system and oven 100 have several functions. Some
of the peripheral functions include the containment of grease and
odor, the containment of microwaves, heating of the oil contained
in the vat 110, rotation of the carrousel 170 and automatic
dispensing of the food products 12.
The containment of grease and odor is carried out by various
features all of which may be individually incorporated or combined:
(1) designing the system and oven 100 such that the flow of air
(and grease and odors) follows a path in through the frontwall 101
and out through the vent 120; (2) enclosing the vat 110 of oil 112
within the oven 100; (3) inhibiting the oil 112 from being
transported out of the pan 130 by the food products 12 or the arms
174; and/or (4) fabricating an integral/unitary grease containment
compartment 270 (FIGS. 22-23) which may be quickly removed from the
oven 100e and replaced.
As previously described, the vent 120 includes a blower (not shown)
which draws air through any space between the sidewall 142 and the
hood 190 (whether opened or closed) and through the gaps between
the perimeters of the doors 156 and 158 and the inner dimensions of
the chute 150. Air will then be drawn through the slot 105 and into
the main body of the oven 100 where it mixes with air borne grease.
The air entrained with grease then exits through the vent 120.
Relating to the third means of containing grease and odors, both
the internal portion 132 and the external portion 134 of the pan
130 may be slanted at an angle oblique to the horizontal to keep
the oil 112 in the vat 110 and to inhibit transportation of the oil
to the external portion 134 of the pan 130 and through the opening
144. The slope in the external portion 134 of the pan 130 will
cause the oil which drains from the food products 12 to drain into
the vat 110 as the carrousel 170 moves the food products 12 out of
the vat 110 and into the external portion 134 of the pan 130.
The containment of microwaves within the system and oven 100 is
carried out by limiting the openings or gaps to the oven and by the
design of the circuitry for the microwave power source (depicted by
reference number 109). Two (2) switches (a primary and a backup
switch, both not shown) should be placed on either the frontwall
101 or the sidewall 142. The switches are contained in the
circuitry for the microwave power source 109. When hood 190 is
closed the switches are closed and the microwave power source 109
will be turned on. When hood 190 is slightly opened, the switches
will open causing the microwave power source 109 to be turned off
and instantaneous dissipation of the microwaves. Another feature
which will assist in containing the microwaves is limiting the
clearance, gap or opening between the arms 174 and the front wall
101. A clearance of less than ten (10) centimeters is preferred to
inhibit microwaves from passing to the external portion 134 of the
pan 130.
Any portion of the microwave field which passes into the external
portion 134 of pan 130 will be further contained by the double-door
156, 158 mechanism of the chute 159. More specifically, as food
products 12 drop through the opening 144 and pass through the door
156, the door 158 will remain closed. Microwaves will be blocked by
the door 158 which contains a gap of approximately one-eighth of an
inch between the perimeter of the door 158 and the internal
dimensions of the chute 150. As the food product 12 passes through
the first door 156, the first door 156 will close. When the food
product 12 reaches the second door 158, the first door 156 will be
closed to block microwaves as discussed with respect to door
158.
Another function of the oven 100 is to heat and filter the oil 112.
The oil 112 will be heated by an oil circulation system as
discussed above with respect to FIG. 1, reference numbers 24, 27,
28 and 29.
The means for rotating the carrousel 170 is as follows: The
circuitry relating to the motor 160 may be designed such that the
motor will remain running when hood 190 is open or such that the
motor 160 will shut down when the hood 190 is open. When motor 160
is running it will drive shaft 162 which in turn drives hub 172.
Hub 172 drives the arms 174.
Another function of the oven 100 is to automatically dispense the
food product 12 as the carrousel 170 moves the food products 12
through the external portion 134 of the pan 130. Each food product
12 will eventually be moved over opening 144 at which time it will
drop through opening 144 into chute 150. Chute 150 will transport a
food product 12 through the first and second doors 156, 158 such
that the food products 12 are automatically dispensed while the
oven 100 is operating, thereby eliminating the need to manually
open the oven and turn off the microwaves for the removal of food
products.
The main function of the system and oven 100 is to prepare the food
products 12 by moving the food products 12 simultaneously through
the oil 112 and a microwave field. An operator (not shown) will
pick up a desirable number of food products 12 to be prepared. The
operator will then open the hood 190 at which time the microwave
source 109 will be turned off and the carrousel 170 may or may not
be rotating. The operator will then place the food products 12, one
each between consecutive arms 174. The operator next closes the
hood 190. The arms 174 of the carrousel 170 will push or rotate the
food products 12 through the external portion 134 of the pan 130
and into the internal portion 132 of the pan 130. The hinge
mechanism 180 between each arm 174 and the hub 172 allows each arm
174 to independently and vertically adjust to the bottom of the pan
130 as the arm 174 moves across the slope of the pan 130. For
example, as the food products 12 move through the slot 105 the arms
174 and the food products 12 move down into the oil 112 according
to the slope of the internal bottom of the pan 130. Simultaneously,
the food products 12 will be moving through the microwave field
emanating from the microwave source 109. The screen 139 over the
internal portion 132 of the pan 130 prevents the food products 12
from floating to the surface of the oil 112. Eventually, each food
product 12 and arm 174 will begin to move up according to the slope
of the bottom of the pan 130. Once the food product 12 moves out of
the pool of oil 112 excess oil will drain from the food product 12.
As discussed above, this excess oil will be drained back into the
vat 110. The carrousel 170 will continue to move the food products
12 until they drop through opening 144 and into chute 150.
Referring to FIG. 17, another embodiment of a pan 130a is shown. In
this embodiment, the bottom 136 of the pan 130a is structured to
include a bottom having a constant slope or incline oblique to the
horizontal to assist in draining of the oil 112 from the food
products 12 into the vat 110.
Referring to FIG. 18, another embodiment of an oven 100b and pan
130b are shown. In this embodiment both the pan 130b and the bottom
136b of the pan 100b are horizontal and the pan 130b becomes the
container for the oil 112. The carrousel 170 (not shown) will still
rotate the food products (not shown) through the oil 112b but the
carrousel 170 (not shown) will not have hinges between the arms and
the hub 172. The frontwall 101 terminates when it intersects a step
or ledge 201 which runs horizontally for a short distance to
dissipate microwaves before they exit via slot 105 between ledge
201 and base 106. In this embodiment, pan 130b may not contain an
opening 144 for the automatic dispensing of food products 12. In
other regards, this embodiment is similar to the embodiment shown
and described with respect to FIGS. 10 and 16.
Referring to FIG. 19, another embodiment 100c of a system and oven
are shown. In this embodiment the motor (not shown) will drive one
of the three gears 210, 212 or 214. The gear which is driven by the
motor will in turn drive the other gears. The gears 210 and 214
will drive a belt or chain 220. The chain 220 drives arms 222
around pan 221. Arms 222 will be connected to the chain 220. For
example, the chain 220 may contain apertures 224 and prongs 226.
The end 223 of the arm 222 may contain a passage for receiving
prongs 226. The arm 222 is inserted into aperture 224 with the
prongs 226 inserted in the passage in the end 223 of the arm 222.
Arm 222 will be driven by the chain 220. The prongs 226 in
conjunction with the passage will function as a hinge for the arm
222. The main concept relating to this embodiment is to increase
the pathway of the food product 12 within the oven 100c. The bottom
of the pan 221 may be horizontal, inclined or a combination of
both.
Referring to FIG. 21, another embodiment of the oven 100d is shown.
This embodiment contains pulleys 230a-f. The pulleys 230 will drive
belts 232a-c. The drive belts 232a-c include flexible teeth 234 for
engaging the food product 12. The first belt 232a carries the food
products 12 through a first door 250 with a spring hinge 252,
through a second door 254 with a spring hinge 256, and through the
opening 105d in the front wall 101d of the oven. The first belt
232a also carries the food products down into the pool of hot oil
112d. Once the food product 12 moves into the pool of hot oil 112d,
a horizontally disposed cover 260 will prevent the food product 12
from floating to the surface of the pool of hot oil 112d. Once the
food product 12 moves to the end of belt 232a it will be
transferred to the second belt 232b which moves the food product 12
through the pool of hot oil 112d and through the microwave field.
The third belt 232c will carry the food product 12 out of the pool
of hot oil 112d, out of the oven 100d and automatically dispense
the food products 12 into an outlet chamber 240 which includes a
first door 242 with a spring hinge 244 and a second door 246 with a
spring hinge 248.
Referring to FIGS. 22-23, another embodiment of the oven 100e is
shown. In this embodiment the vat 110e, the pan 130e and the chute
150e (if included) are all fixed together to form an integral or
unitary grease containment compartment 270. The oven 100e contains
a cavity 272 for receiving the grease containment compartment 270.
The grease containment compartment 270 may be quickly inserted and
quickly removed from the oven 100e via commonly known devices such
as latches 288. The oven 100e and grease containment compartment
270 may be constructed so that the compartment 270 slides into the
oven 100e either vertically or horizontally. A microwave source
109e is mounted within the oven 100e directly above the cavity 272.
The grease containment compartment 270 is enclosed except its
topwall 271 will define a microwave entry 273 and a vent opening
275, and the external portion 290 may contain a retractable hood
190e, and/or loading and unloading openings or structures. A filter
or a thin sheet of plastic 274 (e.g. one mil. in thickness) either
comprises the microwave entry 273 or is placed over an opening in
wall 276 of the oven 100e to allow microwaves to pass while
preventing grease from contaminating the microwave generator 109e.
The wall 276 of oven 100e also defines a vent opening. A vent line
120 is connected over this opening. The vent line preferably
contains multiple grease removing filters 280, below a charcoal
filter 282, which is below a blower 284. All of the filters 280,
282 and the vent line 120 should be structured such that the
filters are replaceable. A screen 286 or a demister pad (not shown)
is mounted over the vent opening 275 below the vent line 120. The
lower end 164 of shaft 162 includes a conical gear and a quick
connect/disconnect coupling (not shown). The hub 172e (with only
one arm 174 shown) contains an internal gear 292. The quick
coupling may be activated with an upward motion allowing the hub
172e to be quickly engaged or disengaged for insertion or removal
of the grease containment compartment 270. A plug or electrical
contact surfaces (both not shown) are located in and between the
oven 100e and the grease containment compartment 270 for turning
the microwave generator 109e and the motor 160 on or off depending
on whether a hood or some other similar device in the grease
containment compartment 270 is opened or closed. It would be
preferable to construct the grease containment compartment 270 such
that its dimensions allow it to fit within a briefcase. This allows
a service person to bring a clean grease containment compartment to
the location of the oven 100e in a briefcase, remove the dirty
grease containment compartment, replace the dirty compartment with
a clean compartment, place the dirty grease containment compartment
in his or her briefcase and to tote the dirty compartment to
another location to be cleaned.
Further features and advantages of the invention are as
follows:
Referring to FIG. 10, the carrousel 170 will preferably turn at
about 1 to 1.2 rotations per minute meaning the food product 12
will be within the oven for approximately thirty to forty-two
seconds. This should allow sufficient time to prepare the food
product 12 in the hot oil and microwave field.
The carrousel 170 could be designed to include twenty-four (24)
arms 174 so that it will have the capacity to contain twenty-four
(24) food products 12.
All surfaces which will come into contact with the food product 12
(such as the arms 174 and the pan 130) should be coated with TEFLON
or some other suitable material.
Relating to all embodiments of the invention disclosed, all objects
which may be within the microwave field should be made of a
non-ferrous material to prevent burning of the object.
Relating to the external mode of heating the food product 12, the
various embodiments of the invention have been described as
including a vat 110 containing a pool of oil 112. However, various
other known mechanisms and media used for external heating of a
food product may be incorporated. Some examples of other types of
heating mechanisms and media include a vat for heating with hot
air, with hot steam, etc. for heating by convection and/or
conduction.
The vat 110 and/or the carrousel 170 may also be constructed to
include structures for rotating and spraying hot oil (not shown but
similar to the devices shown in FIGS. 1-7) in order to heat the
food product 12 by spraying hot oil over the outer surface of the
food product 12.
The various openings or gaps to and from the oven such as the gap
between slot 105 and arms 174 may be made small enough or the
wavelength of the microwaves may be varied such that the leakage or
emission of the microwave radiation is less than the regulatory
limit in which case the hood may not be required. The current
regulatory limit is the power density of the microwave radiation
emitted by a microwave oven shall not exceed one (1) milliwatt per
square centimeter at any point 5 centimeters or more from the
external surface of the oven, measured prior to acquisition by a
purchaser, and thereafter, 5 milliwatts per square centimeter at
any point 5 centimeters or more from the external surface of the
oven.
* * * * *