Note: Descriptions are shown in the official language in which they were submitted.
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B~CKGROUND OF l'HE INVENTION
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This invention generally relates to a method and
apparatus for containerized, high-speed, batch cooking of scram-
bled eggs. The method and apparatus of the present invention
are intended generally for use in restaurants wherein
it is desired to cook individual servings -of scrambled eggs
(consisting of from 1 to 8 eggs) in a very short time and
without requiring the cook to continuously stir or manipulate
the egg mixture. The method and apparatus of the present inven-
tion produces a scrambled egg product that is uniformly and
evenly cooked and that is light and fluffy.
The conventional process which has been used for
centuries is to scramble and cook small batches of eggs in fry-
ing pans or on a grill. There are no commercially available
processes for cooking small batches of scrambled eggs that do
not rely upon the use of a hot surface which both cooks and
tends to partially scorch the eggs.
; There have been attempts to produce scrambled eggs
on a continuous basis where large quantities are required. For
example, U.S. Patent No. 3~624,230 to Robinson, Jr. discloses
a method and apparatus for continuously producing a product
which is said to have the appearance and taste of scrambled eggs
from a continuously piped slurry. The method disclosed in the
Robinson patent is limited for use in a commercial-type, in-plant
process with a continuously moving slurry mixture and is not
applicable to batch-type cooking of whole, shelled eggs in a
container, as in a restaurant.
U.S. Patent No. 2,999,024 to Stimpson et al. discloses
a method of preparing an egg product in the nature of a smooth
gelled mass of consistency, color and texture resembling a baked
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custard which is useful for the feeding of infants and invalids.
The method is disclosed as a commercial-type, continuous slurry
process in which high pressure steam is introduced into a pipe
containing an egg mixture slurry to disintegrate the mixture
into a spray-like condition and thereby instantly heat and cook
the particles. As in the above~discussed ~obinson patent, this
method is not applicable to batch-type cooking of small quantities
of whole, shelled eggs in a container.
U.S. Patent No. 2,481,711 to Bemis discloses a method
and apparatus for cooking eggs. The method and apparatus pro-
vides what may be considered a combination of a fried and poached
egg. Steam is introduced to the top surface of the egg within a
container to provide a "poached" upper surface while the bottom
surface of the egg is fried on a griddle at the bottom o~ the
container. The patent does not disclose a method or apparatus
~or making scrambled eggs.
The prior art teaches several processes for continu-
ously treating or cooking egg products or egg mixtures with
steam. For example, U.S. Patent No. 3,113,872 to Jones et al.
discloses a method for treating shelled eggs to destroy patho-
genic bacteria, which method includes a step of admitting steam
in sufficient volume to raise the temperature of the egg product
to about 150F. This method is a continuous, "large scale"
commercial method. U.S. Patent No. 2,766,126 to Hawk discloses
a method for producing a canned egg yolk puree by means of a
continuous, commercial-type process which includes, in one of
its steps, heating egg yolk by steam injection to between approx-
imately 140and 160F. U.S. Patent No. 3,958,035 to Stearns
et al. discloses a method of manufacturing an omelette-type egg
product in which one of the steps includes heating the egg mix
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by steam injection to a temperature in the range of 160 to
170F.
In each of these patents, the disclosed method of
treating an egg product involves commercial applications on a
production line or continuous flow slurry process. None of
these patents discloses a method for produc:ing a substantially
conventional "scrambled egg" product and none of the patents
discloses a method or apparatus for batch-type, containerized
cooking of individual servings of an egg product.
None of the above-discussed patents describes a method
or apparatus for the high-speed cooking of scrambled eggs in
containerized, small batches wherein the eggs are agitated
and cooked in a sealed container at substantially atmospheric
pressure.
None of the above-discussed patents teach or suggest
how to rapidly cook individual servings of scrambled eggs on a
batch basis and at substantially atmospheric pressure. It
would be desirable to provide a method and apparatus for making
scrambled eggs in individual servings or in relatively small
quantities for use in restaurants or in the home wherein the
scrambled eggs could be rapidly cooked in a batch-type process
in a small container and wherein the scrambled eggs could be
automatically cooked evenly and uniformly.
It would be desirable to provide a method and apparatus
for making scrambled eggs wherein additives such as seasoning
or other foods could be introduced into the egg mixture either
before cooking or automatically during cooking.
It would be desirable ~o provide a method for auto-
matically cooking scrambled eggs with steam rapidly and uni-
formly at pressures of less than 15 pounds per square inch
gauge so that the apparatus could be used in the home and inrestaurants without falling under the scope of the various
state and local regulations covering higher pressure steam
devices.
Further, it would be desirable to provide an apparatus
and method for cooking scrambled eggs with steam in which the
cooking process could be contained within a receptacle sealed
; from the surrounding atmosphere to prevent the steam,egg product,
and any cooking gases from being dispersed into the atmosphere.
To this extent, it would also be desirable to provide a vent
system for exhausting all such steam and cooking gas vapors
from the container or receptacle during the cooking process so
that when the receptacle is unsealed at the termination of the
cooking process, no large amounts of steam or other gases would
be present in the container to escape into the atmosphere.
It would be desirable to provide a method of cooking
scrambled eggs which introduces compressed air into the interior
of the eggs during cooking to assist in providing a light and
fluffy product.
It would be desirable in a method and apparatus for
cooking scrambled eggs by steam injection in a container to
provide a baffle within the container during the cooking process
so that steam could be injected at a pressure sufficient to
~ produce violent agitation for thoroughly and uniformly cooking
; the eggs, with the baffle inhibiting spattering of the egg
mix upwardly away from the bottom of the container and thus
maintaining the eggs in the lower portion of the container
around the steam injection jets so that the mass of egg will
be uniformly cooked.
SUr~RY OF THE INVENTION
The present invention provides a novel method for
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making or cooking scrambled eggs and an apparatus for carrying out the method.
The eggs are cooked extremely quickly (in as little as about 8 seconds) and
in a containerized batch, prefcrably a batch oE between 1 to 8 eggs suitable
for 1 or more individual servings. The batch of eggs is thoroughly and
uniformly cooked to a substantially homogenous scrambled egg mass having an
expanded volume and which is light and tender and delectable in appearance
and flavor.
According to one aspect, the present invention provides the method
of cooking of scrambled eggs in a containerized batch comprising the steps
of: A. charging a container with a selected batch of uncooked shelled eggs
with the yolces unmixed; and then B. introducing a plurality of jets of
steam at spaced, stationary locations in the interior of said batch of eggs
continuously during cooking from a constant pressure source at between 5 and
15 pounds per square inch gauge to disperse said steam therethroughout where-
by said batch of eggs is agitated and heated to produce a thoroughly and
uniformly cooked, substantially homogenous scrambled egg mass having an
expanded volume and which is light and tender and delectable in appearance
and flavor.
Also according to this aspect, the present invention provides the
method of cooking of scrambled eggs in a containerized batch comprising the
steps of: A. charging a generally cup-shaped container with a selected batch
of uncooked shelled eggs; B. eEfecting relative movement between said con-
tainer and a generally cylindrical steam conduit having a plurality of steam
jet orifices to locate said conduit generally coaxially with the vertical
center line of the container and with said orifices within said batch of
uncooked shelled eggs; CO sealing said container from the ambient atmosphere;
D. introducing a plurality of jets of steam from said orifices at spaced,
stationary locations in the interior of said batch of eggs radiating general-
ly outwardly from said conduit to disperse said steam therethroughout whereby
said batch of eggs is agitated and cooked; E. simultaneously with step D,
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continuously venting said container to a condenser to allow escape oE steam
from said container to malntain the interior volume of said container at
substantially atmospheric pressure; and then PO terminating step D in response
to a predetermined condition after said batch of eggs is thoroughly and
uniformly cooked to a substantially homogenous scrambled egg mass having an
expanded volume and which is light and tender and delectable in appearance
and flavor.
In the preferred embodiment, a plurality of jets of steam and
another gas, for example air, are introduced into the interior of the batch
of eggs.
Although the use of jets of steam ox jets of air and steam for the
batch preparation of scrambled eggs has not previously been used, steam has
been used in other environments for cooking foods~ and steam nozzles have
been used to introduce steam into food holding containers or the like.
Typical of prior devices of that type are those shown in United States
Patent Nos. 218,497; 1,~61,653; 1,522,79~; 1,52~,623; 2,967,773; and
3,790,931.
In the present method the jets of steam and air are preferably
introduced in about the geometric center line of the batch of eggs and the
jets of steam and air are directed outwardly throughout the egg mixture.
Preferably, the container is sized to provide a free space for expansion of
the batch of eggs upwardly as their volume increases during cooking and
because of the introduction of steam and entrainment of air. A baffle means
~ or plate may be introduced into the free expansion space in the container
; above the batch of eggs to prevent the eggs from spattering upwardly an
undue amount and to contain the eggs in the lower portion of the container
in about the region in which ~he plurality of jets of steam and air are
being introduced.
According to another aspect the present invention provides an
apparatus for cooking scrambled eggs in a containerized batch comprising:
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a support frame; an open-mouthed container having a lower holding portion for
receiving a batch of uncooked shelled eggs and having an expansion free space
above said lower holding portion; cover means on said frame for engaging the
mouth of said container and holding said container :in an upright position;
conduit means depending from said frame and having a plurality of discharge
: orifices for supplying a plurality of jets of either steam or steam combined
with at least one other gas, said conduit means adapted to be received within
said container for discharging said jets into the interior of said batch of
.;. eggs to disperse said steam therein whereby said batch of eggs is agitated
and cooked; and means for continuously venting said container to allow escape
of gases from said container to maintain the interior volume of said container
at substantially atmospheric pressure as said batch of eggs is thoroughly
and uniformly cooked to a substantially homogenous scrambled egg mass having
an expanded volume and which is light and tender and delectable in appearance
:~ and flavor.
Also according to this aspect the present invention provides
apparatus for cooking scrambled eggs in a containerized batch comprising:
a support housing; means in said housing for supplying compressed inert gas;
means in said housing for supplying pressurized steam; an open-mouthed cup-
; 20 shaped container for holding a batch of shelled eggs; a cover assemblysupported from said housing and presenting a downwardly facing cover surface
for secalingly interlocking the mouth of said container and holding said
container upright during cooking of said batch of eggs; a hollow cylindrical
tube projecting downwardly through said cover assembly and having a plurality
of discharge orifices for discharging a plurality of jets of steam and air,
said tube adapted to be recei.ved within said container for discharging said
jets into the interior of said batch of eggs to disperse said steam and air
therethroughout whereby said batch of eggs is agitated and cooked; a baffle
plate above said plurality of discharge orifices for inhibiting the upward
spattering of said batch of eggs during introduction of steam and air into
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said container; a steam supply conduit connec-t:ing said means for supplying
steam to said hollow cylindrical tube; .m air supply condu:it connecting said
means for supplying compressed air to said steam supply conduit; a valve
: located in said air supply conduit; a valve located in said steam supply
conduit downstream of the connection between said steam supply conduit and
said pressurized gas supply conduit; a vent chamber connected with said cover
assembly and communicating with said downwardly faci.ng cover surface, said
chamber surrounding a portion of said cyl:indrical hollow tube whereby said
container may be continuously vented into said chamber to allow escape of
steam from the container for maintaining the interior volume of the container
at substantially atmospheric pressure; and control means for actuating said
steam and inert gas supply conduit valves to admit the flow of steam and air
to said tube and to subsequently terminate the flow of steam and inert gas
in response to a predetermined condition after said batch of eggs is thorough-
ly and uniformly cooked to a substantially homogenous scrambled egg mass
having an expanded volume and which is light and tender and delectable in
appearance and flavor.
Preferably, the interior shape of the container and tube orifices
are proportioned and located to enhance reflection of the steam and air back
through the egg mixture to enhance complete cooking.
The baffle plate is preferably generally disc-shaped and secured to
the injection tube above the plurality of orifices in generally concentric,
coaxial alignment with the tube. When the container is engaged with the
cover assembly with the tube projecting therein, the baffle plate lies within
the upper portion of the container generally parallel to, and below, the
cover surface to prevent upward spattering of the egg mixture and to maintain
the egg mixture generally in the lower portion of the container about the
steam and air injection orificesO
Preferably, the cover assembly has an annular aperture extending
from the underside, or downwardly facing sealing cover surface in communication
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with the interior of the container and the vent chamber for allowing the
steam, air, and other gases to vent from the container during cooking through
that aperture. Preferably, the vent chamber is connected to a condenser so
that the vented steam may be condensed.
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The method of the present invention when effected
by the apparatus of the present invention, is completely auto-
matic and requires no operator manipulation of the eggs during
cooking. As a result, the scrambled egg product can be repeatedly
made in individual batches of substantially identical and consis~
tent density, texture, flavor, and c~uality.
The method and apparatus of the present invention
produce a scrambled egg product without the use of a heated
griddle or cooking surface, such as a frying pan, which is com-
monly used in preparation of scrambled eggs. Cooking of scrambledeggs on a grill, griddle, or in a frying pan xequires that an
egg mixture be made by mixing eggs and that the mixture be
placed on a heated surface so that at any one time, part of the
egg mixture is in contact with the heating surface and the re-
maining portion of the egg mixture lies above the heating surface
and not in direct contact therewith. This leads to non-uniform
cooking of the egg mixture and requires constant operator activ-
ity with respect to stirring the egg mixture on the heated sur-
face. Depending upon the skill and care of the operator, the
egg product will have portions which are more or less cooked
~ than other portions of the egg product. Typically, some portions
; of the scrambled egg product are "overcooked", some portions are
"undercooked", while other portions may be "just right".
It is believed that scrambled eggs cooked according
to the method of the present invention, being constantly agitated,
uniformly heated, and not in contact with heated grill surfaces,
become so uniformly cooked that all portions of the scrambled
egg product are cooked to the same and proper degree such that
very little, if any, of the scrambled egg product is either
overcooked or undercooked. Therefore, a scrambled egg product
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properly cooked in accordance w:ith the method of the present
invention will have very few overcooked or undercooked parts
and will therefore be more uniform :in quality and consistency
and more properly digestible.
Numerous other advantages and features of the present
invention will become readily apparent from the following de-
tailed description of the invention and of one embodiment
thereof, from the claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings forming part of the
specification, and in which like numerals are employed to
designate like parts throughout the same,
Figure 1 is a perspective view of the apparatus of
the present invention with a portion of the housing wall cut
away to show internal components;
Figure 2 is a front elevation view of the apparatus
of the present invention with a portion of the housing wall
cut away to show internal components;
Figure 3 is an enlarged, fragmentary, partial cross-
sectional view of the container and steam/air injection tubeassembly of the present invention;
Figure 4 is an end view of the injection tube taken
generally along the plane 4-4 of Figure 3; and
Figure 5 is a simplified control diagram for the
apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While this invention is susceptible of embodiment in
many different forms, there is shown in the drawings and will
herein be described in detail one specific embodiment, with the
understanding that the present disclosure is to be considered
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as an exemplification of the principles of the invention and
is not intended to limit the invention to the ernbodiment illus-
trated.
The precise shapes and sizes of the components herein
described are not essential to the :invention unless otherwise
indicated, since the invention is described with only reference
to an embodiment which is simple and straightforward.
It will be understood tha1: the references made herein,
and in the claims, to various terms such as "vapor" and "gas",
that the same are merely illustrative. The terms "vapor" and
"gas" are used herein in a non-technical sense, and are intended
to include finely dispersed liquids in an air or other gas stream,
true vapors, true gases, and the like, without regard to the
critical temperatures or pressures thereof, or the like.
For ease of description, the apparatus of this inven-
tion will be described in normal operating position, and terms
such as upper, lower, horizontal, etc., will be used with refer-
ence to this normal operating position. It will be understood,
however, that apparatus of this invention may be manufactured,
stored, transported and sold in orientation other than the
normal operation position described.
The apparatus of this invention has certain conven-
tional boiler systems, condenser systems, gas compressor systems,
electronically and pneumatically actuated valves, and control
mechanisms and systems, the details of which, though not fully
illustrated or described, will be apparent to those having skill
in the art and an understanding of the necessary functions of
such components and systems.
The method of cooking scrambled eggs according to
the present invention will first be described in general terms.
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Following the general description of the method, a preferred
embodiment of an apparatus for effecting the method of the
present invention will be described in detail. In connection
with the description of the preferred embodiment of the appara-
tus, certain details of the me~hod of cooking scrambled eggs
according to the present invention, as well as alternative
steps in the method of the present invention, will be discussed.
In general, a relatively small number of eggs, such
as a batch of from one to eight shelled uncooked eggs, can be
cooked and scrambled according to the method of the present in-
vention in a batch-type process in a relatively short time,
essentially automatically and without re~uiring operator action
during cooking. Specifically, a batch of shelled, uncooked
eggs is first placed within a container. Additional ingredients,
such as butter, cream, salt, and pepper may also be added. The
eggs and ingredients need not be mixed. Steam is then injected
into the interior of the batch of eggs in the container to agi-
tate and cook the eggs.
Preferably, a steam injection conduit having a plurality
of injection orifices for discharging jets of steam is provided.
When that is the case, the conduit is juxtaposed with the con-
tainer so that the portion of the conduit with the steam injec-
tion orifices is submerged within the interior of the batch of
eggs. This may be effected as by moving the container relative
to the conduit, or by moving the conduit relative to the container.
Ideally, the conduit is placed approximately at the geometric
center line of the batch of eggs so that when the jets of steam
are directed outwardly of the orifices through the interior of
the batch of eggs the steam is dispersed therein. Preferably,
compressed air is also injected through the same, or different,
orifices along with the steam to aid in agitating the egg mix-
ture and to provide aeration of the mixture which results in a
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fluffier product.
While the jets of steam and air are being injected
into the batch of eggs, the container is sealingly engaged adjacent
its top with a cover to prevent the steam, air, and any resulting
cooking gases from being released directly to the surrounding
atmosphere. Also, while the jets of steam and air are being
injected into the batch of eggs, the container is continuously
vented, preferably to a remotely located condenser, to allow
escape of steam and air from the container to maintain the
interior volume of the container at substantially atmospheric
pressure. Finally, the injection of the jets of steam and air
is terminated in response to a predetermined condition, such as
in response to an elapsed time interval, temperature, or totalized,
steam flow or the like, after the batch of eggs is thoroughly
and uniformly cooked to a substantially homogenous scrambled egg
mass having an expanded volume and which is light and tender
and delectable in appearance and flavor.
The preferred pressures, temperatures, and flow rates
of the steam and air depend on, among other things, the shape
and size of the container and injection means or tube. Conse-
quently, the values for these parameters will be discussed with
reference to the specific embodiment of the apparatus for effec-
ting the method of the present invention which will next be
described.
With reference to Figure 1, there is illustrated a
scrambled egg cooking apparatus of khe present invention which
is designated generally by the numeral 10. The apparatus 10 is
preferably a self-contained, compact, mobile unit providing a
support frame assembly and comprising a lower housing 12, a
¢onduit housing 14 above the lower housing 12, and a control valve
housing 16 cantilevered from the conduit housing 14. The housings
preferably have stainless steel walls with generally smooth
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surfaces free of apertures or other irregu:Larities to permit
rapid and effective cleaning of the unit concomitant with normal
sanitary practices associated with food processing equipment.
Mobility of the apparatus 10 is accommodated by wheels 18 de-
pending from the bottom of the lower housing 12. The lower
housing 12 has a top working surface 20 which may function to
hold food items and other implements before, during, and after
cooking of the scrambled eggs.
The eggs are cooked in a container 26 which may be
releasably engaged with a holding means or cover assembly 28.
The cover assembly 28 projects downwardly from the underside
of the control valve housing 16 and has within it a steam in-
jection conduit and steam vent passage, the details of which
will be described hereinafter.
; As best illustrated in Figure 1, the lower housing
12 serves to contain and support three relatively large compo-
nents. An air compressor 30 is mounted on the lower floor of
housing 12 and an air receiver tank 34 is connected to the air
compressor output 30 and is mounted thereabove. For cooking
a relatively small number of eggs, it has been found in an
actual working embodiment of the apparatus of the present inven-
tion that an air compressor of about 1/4 horsepower will provide
sufficient air flow when coupled with an air receiving tank of
sufficient capacity and design to hold compressed air between
15 and 30 psi gauge.
Steam is supplied to the batch of eggs from a steam
generator 40 mounted within the housing 12. It has been found
that in an actual working embodiment of the apparatus of the
present invention that a non-recirculating boiler can be used.
The boiler can be refilled with water after a certain number
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of cooking cycles (e.g., at the end of a day in a reskaurant).
To this end, for an operation intended to make 150 batches of
scrambled eggs per day (each batch comprising between one and
eight egss), the boiler sh~uld be designed to sup~ly the steam
at 10 to 12 psi gauge and at a rate oS about 2 fluid ounces of
water per cooking cycle (or 2 ounces of water by weight per
cooking cycle). For best results, if saturated steam is used,
it is desirable to prevent carry-over of moisture in the steam
and to this extent appropriate steam dryer baffles may be em-
ployed.
As will be explained in detail hereinafter, the con-
tainer 26 is vented during cooking to maintain the interior
volume of the container substantially at atmospheric pressure.
To avoid exhausting steam, air, and any resulting cooking gases
directly into the ambient atmosphere at objectionable temper
atures and pressures, a condenser 44 is preferably provided
within the lower housing 12 ~o receive the steam, air, and
cooking gases through a vent conduit in which the steam cools
and begins to condense. The condenser may simply be a finned
plate against which the steam, air and gases are directed and
which, at the temperatures and pressures involved, sufficiently
condenses steam to avoid excessive escape of steam into the
ambient atmosphere.
The actual design and construction of the air com-
pressor 30, air receiver tank 34, steam generator 40, and con-
denser 44 may be of any suitable conventional types, the
specific configurations, sizes, and designs being varied as
necessary to accom~odate the pressures, temperatures, and flow
rates of the steam and air used to cook the scrambled eggs in
accordance with the method of the present invention.
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An appropriate control panel 49 (Figure 2) may be pro~
vided within the lower housing 12 to provide individual control
over the various major components such as the compressor 30,
steam generator 40, and other components such as power-actuated
valves.
The air receiver tank 34, the steam generator 40, ancl
the condenser 44 all communicate with the container 26 through
conduit 98 in the cover assembly 28 via suitable pipes or con-
duits which pass from the lower housing 12, up the conduit
housing 14, and throuyh the control valve housing 16. In Figure
1, the air supply conduit 48 is shown connected to the top of
the air receiver tank 34 and the steam supply conduit 52 is
shown connected to the top of the steam generator 40. A vent
conduit 56 is connected to the cover assembly 28 and enters the
side of the conduit housing 14. From there it passes to the
lower housing 12 where it is connected to the condenser 44 (the
connection at the condenser 44 is hidden from view in Figure 1).
Of course, suitable conventional pressure relief mechan-
isms and vents (not illustrated) may be provided on the air com-
pressor 30, the air receiver tank 34, the steam generator 40,
and the condenser 44 in accordance with normal design practice
for these types of components in the application to which they
are adapted, but such safety devices will not be further dis--
cussed herein.
The cover assembly 28, the container 26, and the steam
supply, air supply, and vent conduit connections to the cover
assembly 28 will now be described in more detail. Figure 3
illustrates an enlarged view of the container 26 s~alingly en-
gaged with the cover assembly 28. The container 26 is generally
cup~shaped and open-mouthed and has a substantially
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upstanding vertical, cylindrical wall portion 60 extending above
a generally concave rounded bottom portion 62 The batch of
eggs or mixture of eggs plus other ingredients 66, is placed in
the container 26 and occupies a lower holding portion, indicated
by the bracket 68 in the container 26. The upstanding sidewall
or cylindrical wall portion 60 of the container 26 extends a
sufficient distance above both the bottom portion 62 and lower
holding portion 68 to provide a free space, indicated by the
bracket 70, for expansion o~ the batch of eggs during cooking.
The containex 26 is preferably made of stainless steel
and has a smooth interior surface which may be coated with a
synthetic resin polymer, such as the product sold under the
trademark Teflon, to prevent sticking of the scrambled eggs
thereto. The exterior portion of the bottom of the container
may be formed into a base or pedestal 74 to allow the container
26 to be supported in the upright vertical orientation when
disconnected from the cover assembly 28 and placed on a flat
surface, such as the working surface 20 on the top of the lower
housing 12. A handle 76 may be secured to the container 26 by
suitable means r or may be integral therewith, to provide a
means by which the container 26 may be manipulated by the
operator. Additionally, a plurality of insulating members 78
may be secured to the exterior of the container 26 to provide
: a cool gripping surface should the operator choose to grasp
the cylindrical sidewall portion 60 of the container 26 rather
than the handle 76. The insulating members may be of a material
which has relatively poor heat conduction properties, such as
wood, and they may be secured to studs 80 welded to the outside
of the container sidewall 60. The studs 80 may have an annular
groove 82 for receiving a suitable adhesive 84 which secures
the insulating members 78 to the studs 80.
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For cooking between 1 and 8 eggs, it has been found
that a container with an interior height of between 4 and 8
inches, preferably about 6-1/2 inches, and having a maximum
inside diameter at the mouth of between 3 and 5 inches, pre-
ferably about 3-7/8 inches, will yield excellent results with
the steam injection tube having a design that will be described
hereinafter and with the steam and air flow parameters having
values that will be hereinafter discussed. Preferably, the
rounded bottom 62 of the container has an inside radius of about
3 inches. It has been found that when stainless steel is used
as a container material, a wall thickness of about 0.06 inch
is sufficient to provide the requisite structural integrity
and an overall heat sink capacity which,when combined with the
preferred steam and air flow rates and temperatures, yields an
excellent scrambled egg product.
The container 26 is adapted for sealingly engaging,
and being held by, the cover assembly 28. To this end, the top
of the container terminates in bayonet-type lugs 85 for inter-
locking with the cover assembly 28. The cover assembly 28 has
a generally disc-shaped cover 88 which presents a downwardly
facing cover surface 90 for sealingly engaging and interlocking
the mouth of the container 26 and for holding the container
upright during cooking of the batch of eggs. To this end, a
flange 92 is provided at the periphery of the cover surface 90
for matingly engaging the bayonet lugs 85 of the container.
The bayonet-type engagement between the container 26
and the cover 88 is of the conventional type wherein rotation of
the container relative to the cover 8g for a certain number of
degrees will bring the container lugs 85 into alignment with
similarly shaped and identically sized apertures in the cover
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flange 92 whereby the container 26 i.s free to drop vertically
downwardly and out of engayement with the cover assembly 28.
Obviously, other types of interlocking and sealing connections
may be employed to effect the same result. A sealing ring 94,
preferably one made from an elastomeric material and having a
generally square-shaped cross section, may be provided in the
flange 92 to assure liquid tight sealing against the top vf the
bayonet flange 85 of the container 26.
An aperture 96 is provided in the center of the cover
88 and communicates with a vent chamber 98. The steam, air, and
cooking gases may be exhausted through aperture 96 from the
inside of the container 26 into the vent chamber 98. The pre-
viously discussed vent conduit 56 is connected to the vent
chamber 98 and conducts the steam, air, and other gases from the
vent chamber 98 to the condenser 44 as previously described.
To provide for safe operation, an interlock is provided
to prevent the steam and/or air from being supplied to the in-
jection tube 110 whenever the container is not sealingly engaged
with the cover assembly 28. To this end, a lug 132 is provided
on the exterior of container 26 to engage a limit switch 134 on
the front of the conduit housing 14 when the container 26 is
properly. sealingly engaged with the cover assembly 28 as illus-
trated best in Figure 1. The limit switch 134 is interlocked
with the control system for the steam and air supply as will be
described hereinafter, to prevent steam and air from being in-
]ected when the container 26 is not properly sealingly engaged
with the cover assembly 28.
Loca-ted partially within, and projecting downwardly
from the cover assembly 28 is a means 110 for injecting steam
and/or air into the interior of the batch of eggs within the
- 20 -
.
container 26. This means 110 is preferably a generally cylin-
drical conduit or tube having a plurality of discharge orifices
114 in the cylindrical wall. The conduit or tube 110 is in
communication at a first end, 116, with a line or conduit 118
which supplies air and steam. The injection conduit 110 has
a second end which includes a generally fiat, disc-like closure
member 120 defining a plurality of orifices 122 as best illus-
trated in Figure 4.
For the size and shape of the container 26 previously
described, it has been found that a good scrambled egg product
is produced when the orifices 114 are located in three vertically
spaced-apart circumferential rows about the conduit 110. Pre-
ferably, the orifices in each row are located at 60 increments
around the tube. The orifices in the middle row are displaced
in one direction 20 circumferentially from the orifices in the
bottom row and the orifices in the top row are displaced in the
same direction 20 circumferentially from the orifices in the
middle row. That is, each orifice in the middle row is located
on a line 20 from a parallel line passing through an orifice
of the upper row and 20 from another parallel line passing
through an orifice in the bottom row.
Preferably, each orifice is circular and has a dia-
meter of about 1/16 inch and the conduit or tube 110 has an out-
side diameter of 0.675 inch. For use with a container of the
size and shape previously described, it has been found that a
good scrambled egg product is obtained when the conduit or tube
110 extends to within a distance of between about 0.06 inch and
1.0 inch above the bottom portion 62 of the container 26. Each
orifice 114 in the cylindrical wall of the tube or conduit 110
is illustrated as being aligned about an axis which is per-
pendicular to, and radiates out from, the central longitudinal
axis of the tube. If desired, the orifices 114 may be angled, as
downwardly at about 15~, within the wall of ~ube 110.
The orientation and direction of the orifices with
respect to the concave interior cup surface, which may be parti-
ally spherical or parabolic in shape~ are such that the steam
and/or gas jets will be redirected ox reflected by the cup sur-
face back through the egg mass to maximize their agitating and
cooking effect. This produces a more completely cooked product.
The number of orifices, the number of rows of orifices,
and the array or configuration of the orifices on the tube n~y be
~aried. For a given batch of eggs, it is not essential that all
orifices be disposed within the egg mixture. In Figure 3, ~he
dashed and solid lines 124 and 126, respectively, illustrate the
relative surface heights of mixture of two and four eggs. In ~he
case of two eggs, the top row of orifices 114 is not submerged
within the egg mixture 66 whereas with four eggs, the top row
is submerged.
A baffle means or baffle plate 130 may be provided
within the container 26 in the expansion free space 70 to prevent
the egg mixture from spattering upwardly beyond a certain height
and to thereby maintain the egg mixture in the lower portion of
the container surrounding the orifices 114 and 122. Further,
~he baffle plate 130 prevents the egg mixture from spattering
upwardly against inner cover surface 90 and out through the aper-
ture 96 into the vent chamber 98. Baffle plate 130 may be a
substantially flat disc secured to the discharge tube 110 above
the top row of orifices 114 which is in generally coaxial align-
~ ment with the cylindrical discharge tube 110 and is displaced
inwardly of the tube end wall 120 by an amount sufficient tolocate the baffle plate 130 within the container free space 70
abo~e the batch of eggs 66 and with the baffle plate 130 gener-
ally parallel to the surface of the batch of egg~ 66.
-~2-
, ~
,
D~3'r~
Both the conduit 110 and the baffle plate 130 are
preferably coated with a synthetic resin polymer, such as
the product sold under the trademark Teflon, to prevent the
eggs from sticking thereto.
To accommodate rapid disassembly and cleaning of the
injection tube 110 and cover assembly 28, the injection tube
110 is uniquely mounted within the cover assembly 28. The cover
assembly 28 includes the previously discussed vent chamber 98.
To accommodate the conduit or injection tube 110 and provide
vent capacity within the chamber 98, the chamber 98 has a gener-
ally cylindrical wall spaced away from the tube 98. An upwardly
extending portion of the vent chamber 98 terminates in a flange
136 having an annular shoulder 138 on the interior thereof. A
washer 140 is disposed on the shoulder 138 and supports a gener-
ally annular member or gasket 142 having a generally V-shaped
cross-section. The gasket 142 is made of resilient material,
such as rubber, and is adapted to engage an annular groove 144
in the injection tube 110 near end 116. The conduit 118 has an
annular flange 148 which rests on a portion of the upper surface
of the gask~t 142. The conduit 118, the gasket 142, the washer
140, and the flange 136 are all secured together in this arrange-
ment by bushing 150 which is threadingly engaged with the ex-
terior of the flange 136. The weight of the discharge tube 110
is borne along the groove 144 by the inner diametrical surfaces
of the annular gasket 142. Gasket 142 prevents air and steam
from passing from conduit 118 along the outside of injection
tube 110 into the vent chamber 98. Thus, air and steam within
the conduit 118 must flow on the inside of the injection tube
110 and out through the orifices 114 and 122 into the batch
of eggs 66.
When it is desired to remove and clean the injection
tube 110, the injection tube 110 need merely be pulled downwardly.
-23-
3~P.~
Owing to the flexibility oE the gasket 142, the tube 110 becomes
disengaged therefrom and can be fully withdrawn from the cover
assembly 28. If it is desired to remove the cover assembly 28
also, the bushing 150 can be disengaged from the flange 136 and
a connection in the vent conduit 56 (not shown) can be similar-
ly released, thereby allowing the cover assembly 28 to be re--
moved from the machine.
The operation of the apparatus 10 will next be described
with reference to the block diagxam illustrated in ~igure 5.
The compressor 30 is coupled to the air receiver 34 for supply-
ing the steam/air mixing conduit 118 and the in~ection tube 110
with pressurized air through conduit 48. A remotely actuated
valve 150, such as an electric solenoid operated valve 151, is
provided in conduit 48 to admit or terminate the Elow of air
through the conduit 48. Steam generator 40 is connected via
conduit 52 to the steam/air mixing conduit 118 and -the in~ection
tube 110. A remotely actuated valve 152, such as an electric
solenoid operated valve, is provided in conduit 52 to admit or
terminate the flow of steam through the conduit. A fill line
154 and fill valve 156 is provided to allow replenishment of
the water supply in the steam generator. The container 26 is
vented through conduit 56 to moisture trap or condenser 44 which
may be periodically drained through drain lines 160 by the open-
ing of drain valve 162.
Preferably, steam and air are admitte~ to the container
26 by an initiating signal, for example, by the operator pushing
a button 164 (Figures 1 and 2~, and the steam and air then flow
into the container 26 to cook the eggs. After cooking, the
flow oE steam ancl air is terminated in response to a predeter-
mined condition. The predetermined condition may be a sensed
batch
- 24
i~,~.
'
temperature, a totalized flow of steam and/or air, or a predeter-
mined time interval during which the steam and/or air is injected.
In the embodiment illustrated in Figure 5, the flow of steam and
air is controlled by valves 152 and 150 which can be opened by
actuation of a momentary contact push button 164 and which are
subsequently closed by a time delay relay or by one or more
timers in the circuit, such as timer 166.
Valves 150 and 152 are interlocked with the previously
described limit switch 134 to prevent their being opened, or if
open, to close them when the container 26 is not properly seal-
ingly engaged with the cover assembly 28. This prevents discharge
of steam and ai.r when the container is not in place for cooking.
A light, such as light or lamp 168, may be provided in
the control system to indicate, upon its bein~ energized, that
the cooking cycle is completed. It may be desirable to provide
a time delay, say for example a 10-second time delay, after the
termination of the steam injection before the light 168 is ener-
gized to insure that all steam and any resulting cooking gases
have been vented to the condenser.
As has previously been described, various components of
the apparatus of the present invention, such as the injection
tube 110, the baffle plate 130, and the container 26 may be coated
with a synthetic resin polymer material, such as the product sold
under the trademark Teflon, to prevent the scrambled eggs from
sticking to the surfaces of the component. The use of such coat-
ings should be carefully considered to insure that they do not
chemically react or break down to produce undesirable or even
poisonous by-products at the temperatures encountered during
cooking of the scrambled eggs in accordance with the method of
the present invention.
In the preferred embodiment of the method of cooking
- 25 -
scrambled eggs accordiny to the present invention, the above
described apparatus is used to inject steam from 6 to 14 pounds
per square inch gauge, preferably between 11 and 12 pounds per
square inch gauge, at a saturation temperature corresponding to
the pressure. The steam is injected for a period of between 6
to 12 seconds, preferably for about 8 seconds. The steam is
injected at a substantially constant rate of flow corresponding
to a rate of about two ounces of water by weight over the dura-
tion of the 8 second steam injection period.
The air is preferably injected for a period of between
3 and 7 seconds, preferably about 5 seconds, with the air in-
jection period commencing with the commencement of the steam
injection period. The air is supplied to the air injection tube
110 at a pressure of between 5 and 15 pounds per square inch
gauge, preferably at about 10 pounds per s~uare inch gauge.
The rate of flow of air into the container is preferably sub-
stantially constant over the injection period and corresponds
to a flow rate of between 1 and 5 gallons of air, measured
at standard temperature and pressure, over the duration of the
air injection period. Preferably, the rate is e~uivalent to
about 2-1/2 or 3 gallons oE air, measured at standard tempera-
ture and pressure, over the duration of the air injection period.
The cycle cooking time,that is the preferred steam
injection time of 8 seconds and the air injection time of 5
seconds, is substantially independent of the number of eggs for
a relatively small number of eggs being cooked. Specifically,
when executing the method of the present invention within the
above-discussed preferred parameters, the cooking times for
batches of eggs comprising anywhere from 1 to 8 eggs are essen-
tially the same. However, as the number of eggs increases, it
-26-
,
may be desirable to increase the dimensions of the cup and/or
steam injection to accommodate the increased mass.
It has been found that when the steam and air is
injected for the time period described above, the interior
temperature of the scrambled egg mass raised to between about
190~and 200F. at the termination of the cooking cycle.
Though the preferred embodiment of the method and
apparatus of the present invention has been described with
reference to the use of steam and air, scrambled eggs can be
effectively made in accordance with the present invention by
the use of steam alone or by the use of steam with other gases.
Such other gases may be inert gases, preferably carbon dioxide
or nitrogen. In any case, such other gases should be purified
or filtered by suitable means.
It is also possible that the steam and/or air may be
injected intermittently. That is, the jets of steam and/or
air may be injected for an interval of a predetermined length
of time and then terminated for another interval of a predeter-
mined length of time and then again injected for an interval
of a predetermined length of time and so on until the desired
degree of agitation and cooking has been achieved.
Though the preferred embodiment is described as using
an injection tube 110 having orifices 114 through which a mixture
of steam and air pass, it may be desirable, in some instances,
to provide an injection tube having separate orifices connected
to a steam supply and another set of separate orifices connected
to another gas supply (such as air). Alternatively, a plurality
of separate tubes may be inserted into the egg mixture. In that
case, one of the tubes may inject steam and another of the tubes
may inject another gas such as air. Alternativelyr all of the
-27-
tubes may inject a mixture of the steam ancl other gas. Prefer-
ably, the orifices 114 are circular. With a circular orifice,
the jet of steam or air will issue therefrom in a generally
conical flow stream for better dispersion throughout the egg
mixture. However, orifices having other shapes may be used.
It is possible with the method and apparatus of the
present invention to add other food items or ingredients to
the scrambled egg mixture. This can be done either before the
egg mixture is cooked or during the cooking. For example, it
is preferred to cook two scrambled eggs as follows:
1) Two medium size eggs are first broken and placed
without their shells into the bottom of the container (the
eggs need not be mixed before cooking);
2) One half tablespoon of milk or cream is added to
the container;
3) One pinch of salt is added to the container;
4) One half teaspoon of margarine or butter is
added to the container;
5) The container is positioned under the cover assembly
and sealingly engaged in place;
6) The apparatus is actuated to cook the mixture.
Instead of adding the additional ingredients to the
egg batch before cooking, the ingredients may be added during
cooking through the injection tube. For example, flavor or
coloring additives in either gaseous or finely dispersed par-
ticulate form could be injected along with the pressurized air
into the egg mixture. Alternatively, liquids, such as milk and
liquid butter could be injected along with the air and/or steam
or through separate orifices in the injection tube or via a
second injection tube.
-28-
It has been found that the scrambled eggs are best
produced when the cup is preheated. To this end, it is pre-
ferred that the empty container 26 first be positioned under
the cover assembly 28 and sealingly engaged in place and that the
machine 10 be actuated to execute a cook c~cle wherein the steam
and air is injected into the container 26 as if scrambled eggs
were being cooked. The hot steam preheats or warms the container
26. The use of the warmed or preheated cup, when used ne~t to
receive a batch of cool, shelled eggs to be cooked, provides a
good scrambled egg product. Since the whole cooking cycle takes
only 8 seconds, the preheating step is not objectionable. How-
ever, if it were desired to be able to cook a batch of eggs
without having to execute the 8 second preheating step, it would
be possible to have one or more containers 26 continuously ex-
posed to a separate preheating device and ready for use. Such
a device might use infrared heat lamps or electric heating ele-
ments inserted into the interior of the containers.
If a number of batches of eggs are cooked in relatively
rapid succession in one container 26, the container may be hot
enough after each batch that it need not be preheated.
It is seen that thoroughly and uniformly cooked
scrambled eggs can be produced very rapidly and without operator
attention during the cooking process with the method and appara-
tus of the present invention. The scrambled eggs are cooked
more rapidly and in less time than can be achieved with the
current frying pan or grill methods and even faster than can
be done by microwave. It has been found that if a batch of
eggs is cooked for 8 seconds in accordance with the method-of
the present invention as described above, the scrambled eggs
can be "recooked" under the same 8 second cycle with no
noticeable burning.
-29-
The method of the present invention allows a certain
"gourmet" treatment inthe cooking of scrambled eggs because
it is possible to add addltional ingredients to the scrambled
egg mixture before or during cooking and, owing to the thorough
agitation of the steam and/or air injection, achieve a highly
mixed product which has good ingredient dispersion throughout.
Further, since the scrambled eggs can be cooked without being
in contact with a hot frying pan or other griddle-type sur~ace,
the scrambled eggs are cooked without any surface burning and
are cooked substantially uni~ormly throughout their entixe mass.
From the foregoing, it will be observed that numerous
variations and modifications may be effected without departing
from the true spirit and scope of the novel concept of the in-
vention. It is to be understood that no limitation with respect
to the specific apparatus illustrated herein is intended or
should be inferred. lt is, ot course, intended to cover by
the appended claims all such modifications as fall within the
scope of the claims.
: 20
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, . . . .
