Cooking system and accessories

A rack invention includes a rack having a rack surface and a plurality of legs attached to the rack surface. Each of the legs is made of wire and has two straight segments extending downwardly from the rack surface and a connecting segment which connects together the straight segments. The connecting segment is shaped so as to allow the rack surface to be placed at one of a plurality of predetermined distances above the surface in the oven. The cooking rack invention also includes a plurality of such racks which may be used together in an oven. In such an instance, the length of the straight segments of one rack are different that those of another rack, so that the racks provide different ranges of height adjustability.

SUMMARY AND BACKGROUND OF THE INVENTION 
The present invention relates to a system and methods for cooking of food 
products. 
The present handle invention includes a handle adapted to replace a heater 
and blower system removably located in a central opening defined in a top 
enclosure of a countertop oven. The handle has a mounting system for 
removably attaching the handle to the top enclosure in order to replace 
the heater and blower system when the heater and blower system is removed. 
The handle enables a user to remove the top enclosure from the bottom 
enclosure by lifting up on the handle when the handle is installed in the 
top enclosure. In this manner, the countertop oven may be converted to a 
food server comprising the handle, the top enclosure, and the bottom 
enclosure. 
The present cooking pan invention includes a pan having a generally flat, 
round bottom member, the bottom member defining a central opening. The pan 
further has an outer peripheral wall extending upwardly and being located 
at the outer diameter of the bottom member, the outer peripheral wall 
having a height of approximately one-half inch. In addition, the pan has 
an inner peripheral wall extending upwardly and being located at the 
periphery of the central opening, the inner peripheral wall having a 
height of approximately one-eight inch. 
The present cooking pan system invention is a system for cooking food in an 
air oven. The system includes a plurality of spaced cup units having side 
walls defining a generally cylindrical configuration which smoothly 
transition into a bottom member with a substantially rounded connection 
between the side walls and the bottom member. The system also includes a 
thin, relatively flat wire frame for holding the cup units in position. 
The wire frame has outer and inner annulus members, wherein the 
circumference of the outer and inner annulus members are determined by a 
diametrical dimension defined by the generally cylindrical configuration 
of each cup unit. The annulus members engage the cup side walls in order 
to secure the cup units in a system configuration permitting the flow of 
heated air between the cup units. 
The present cooking rack invention includes a rack having a rack surface 
and a plurality of legs attached to the rack surface. Each of the legs is 
made of wire and has two straight segments extending downwardly from the 
rack surface and a connecting segment which connects together the straight 
segments. The connecting segment is shaped so as to allow the rack surface 
to be placed at one of a plurality of predetermined distances above the 
surface in the oven. The cooking rack invention also includes a plurality 
of such racks which may be used together in an oven. In such an instance, 
the length of the straight segments of one rack are different that those 
of another rack, so that the racks provide different ranges of height 
adjustability. 
A method invention of cooking foods in an air oven includes using a cooking 
pan having a hole in its center, wherein the air oven cooks food by 
circulating heated air throughout the air oven cook chamber. The 
circulating air is drawn back up into the center of the cooking chamber 
and reheated and directed back down to be circulated around food 
positioned on the cooking pan disposed in the air oven. The hole in the 
cooking pan creates a passage for the circulation of the heated air. 
An alternative method invention of cooking food in an air oven having a 
cooking chamber includes positioning on a rack in the cooking chamber a 
food cooking system. The food cooking system placed on the rack has a 
frame and cup units positioned in the frame. In the method, the air oven 
cooks the food by circulating blower-driven heated air throughout the air 
oven cooking chamber. The circulating air is drawn back up into the center 
of the cooking chamber and reheated and directed back down to be 
circulated around the cup units. The frame cup units are spaced apart in 
order to allow the heated air to flow throughout the cooking chamber and 
between the cups back up into the top of the cooking chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The inventions described in the present application are particularly 
suitable for use with the countertop oven disclosed in U.S. Pat. Nos. 
4,817,509 and 5,165,328, which are assigned to the same assignee as is the 
present application. U.S. Pat. Nos. 4,817,509 and 5,165,328 are 
incorporated by reference as if fully set forth herein. 
A cooking device 10 as illustrated in FIGS. 5, 12, 16, 19 and 20, includes 
a base member 11, a top 12 and a powered heater unit 13. The heater unit 
13 is in locked engagement with top 12 as hereinafter described. The 
cooking device 10 further includes a lower frame bracket 14 and an upper 
frame bracket 15 which are hingedly engaged such as by removable pin 17. 
The brackets 14 and 15 may be integrally secured to the base 11 and top 12 
respectively, or alternatively, they may be removably secured such as by 
snap mechanism 18. 
The base 11 may be suitably formed of a polymeric material that may be 
transparent and includes a circumferential wall 21, an integral lower wall 
22 and a plurality of feet 23. The feet 23 serve to elevate the lower wall 
22 upwardly from a support surface such as a countertop. The lower unit 11 
may include a thickened upper rim 24 defining a slot 26 into which the top 
12 may by lodged. The base 11 may further include a handle 27. The 
circumferential wall 21 further includes an annular rim which serves to 
support the rack 29 on which the food pieces may be disposed. The rack 29 
may be of a wire construction. 
The top 12 of the cooking unit 10 likewise includes a circumferential wall 
31 and an upper wall 32. The wall 32 may be integral with wall 31; for 
example, produced by injection molding, or alternatively, vacuum molding. 
The upper wall 32 has an opening 32' defined therein for receipt of the 
powered heating unit 13. 
The power heater unit 13 is illustrated in FIGS. 5, 12, 16, and 19. The 
power unit 13 includes an outer housing 46, which contains a heater (not 
shown) and a blower blade 43. The outer housing 46 is preferably made of 
injection molded plastic. A motor is preferably located in the area above 
the hinge. A belt extends between the motor and a shaft on which blower 
blade 43 is mounted. 
The heater may be an open coil, resistance wire type, and may be 
thermostatically regulated to maintain cooking temperatures ranging from 
150 to 450+ degrees F. 
The open heater coil is used in order to achieve the lowest possible 
surface watt density. With adequate air flow, such an element is capable 
of transferring maximum heat to the air stream via conduction, while 
operating in the "black" heat range. In order for other types of heating 
elements, such as tubular types, to give off the same wattage given the 
same space and airflow, the heater would glow. Such a high surface watt 
density would result in overheating of the motor blower, the food being 
cooked, and plastic parts through an excessive radiation of heat. In 
addition, such an element would retain too much heat when the unit is shut 
off, causing additional overtemperature problems. 
The heater assembly also incorporates an overtemperature device capable of 
shutting off power to the heater should the thermostat fail. 
The blade 43 creates two air circulations. The first air circulation is 
throughout the heated chamber. The second air circulation passes a small 
portion of air over the heated coils in the heater. In other words, the 
small air current exits radially outwardly from the blade 43, reverses 
direction 180 degrees to be drawn in over the coil, then radially inwardly 
to the center of the heater, then downwardly into the center zone of the 
blade 43. 
Electrical current is fed into the device 10 by way of electric cord 67. 
The cord 67 may include a conventional plug for insertion into a wall 
socket. The electrical current passes through switch mechanism 68 mounted 
in the upper portion 15. The switch 68 includes a sensing mechanism to 
provide shutdown of the unit in the case of overheating in the heating 
chamber and/or motor housing 41. A sensing mechanism may also be included 
which shuts down the unit if the top portion 12 is pivoted upwardly with 
the throw portion of the switch 68 in the "on" position. 
The air fryer disclosed may be placed in operation by pivoting the top 
portion 12 upwardly. Food pieces such as potatoes, bakery goods, pizzas 
and the like may be placed on the rack 29. The top portion 12 is then 
pivoted downwardly to the position illustrated in FIGS. 5, 12, 16, and 19. 
The switch 68 is then activated turning the heating element and the motor 
on. With the blade 43 rotating, air is moved within the chamber formed by 
the lower unit portion 11 and the upper portion 12, as shown in FIG. 19. 
Air is circulated over the resistance coil thereby providing heat to the 
chamber. The temperature will typically be in the range of 150-400 degrees 
F. If desired, a central wall may be mounted in the heated chamber to 
provide a disturbance and thus greater turbulence within the heated 
chamber. 
Unlike conventional devices, the blower of the disclosed fryer is placed in 
the top center of the cooking chamber. The blower wheel is mounted in such 
a way as to project into the cooking chamber, its upper surface being at 
the same level or lower than the upper wall of the chamber. In this 
position, the air thrown off the wheel travels parallel horizontally to 
the upper wall of the chamber until it is directed downward by the radius 
joining the upper wall and the vertical round side wall. The air then 
travels downward until it is again deflected at the base of the outside 
wall by the radius joining the side wall with the lower wall of the 
enclosure. The air is then simultaneously pushed and drawn by the blower 
across the top of and beneath the cooking rack. As the air approaches the 
center of the enclosure, it is drawn up into the open underside of the 
blower wheel, where it is then recirculated through the same pattern 
described above. 
The velocity of the air is not constant within the chamber, since the 
heated air converges as it moves to the center of the unit and is drawn 
into the blower. In the air fryer, the air cools as it contacts the food, 
but simultaneously accelerates as it converges on the center of the 
chamber. This change in velocity compensates for the dropping temperature 
by more effectively exchanging the heat remaining in the air. The result 
is very uniform cooking from the outer edge to the center of the cooking 
rack. The velocity of the air in the oven is preferably very high, in the 
range of 1000-4000 linear feet per minute in the vicinity of the food, 
with a range of 1200-2500 being particularly preferred. 
When cooking items that cover most of the cooking rack, such as pizza, or 
that require a pan, such as cookies, airflow to the underside of the rack 
is hindered from being drawn back into the blower wheel. The trapped air 
swirls rapidly, but cools off significantly, due to inadequate air 
exchange with the heated air mass above the rack. To compensate for the 
above, one or more "mixing vanes" may be located diagonally under the 
cooking rack. This causes the air to form two or more counter-rotating air 
masses that dramatically improve the air exchange under the rack. 
Another method of solving the above mentioned problem associated with items 
that cover most of the rack is to use a cooking pan 250 having a hole in 
the center of the pan, as shown in FIG. 17. FIG. 17 shows a cooking pan 
250 having a large flat-bottom surface 252 and a peripheral side wall 254. 
Peripheral side wall 254 is created by gradually inclining the bottom of 
the flat surface 252 until the side wall 254 is formed. The flat bottom 
252 and peripheral side wall 254 are a continuous surface and the 
peripheral side walls slope upwardly and outwardly from the center 256 of 
the flat-bottom surface 252. The flat-bottom surface 252 of the cooking 
pan 250 has a circular opening 258 at its center 256. The circular opening 
258 has an inner peripheral wall 260 sloping upwardly and inwardly. 
The outer peripheral side wall 254 serves the function of a normal cooking 
pan. The circular opening 258 in the center 256 of the cooking pan 250 
serves a purpose of allowing the cyclonic air to flow through the center 
of the cooking pan 250, thereby reducing the amount of air trapped beneath 
the cooking pan 250. This allows air to circulate more freely through the 
cooking chamber. The hole 258 in the center 256 of the cooking pan 250 in 
a preferred embodiment is approximately two (2) inches in diameter. 
However, other diameters may be more appropriate given the level of 
cyclonic air flow desired. The outside peripheral side walls 254 
preferably slope upwardly and outwardly for approximately 1/2 of an inch. 
The inner peripheral walls 260 preferably slope upwardly and inwardly for 
approximately 1/8 of an inch. In addition, the cooking pan is preferably 
made of a conductive material having a layer of non-stick surface attached 
thereon. 
The hole 258 in the center of the cooking pan allows for increased flow of 
cyclonic air, by allowing air to be drawn back up into the blower wheel 
43. 
The cooking pan is preferably placed directly on top of the rack of the 
cooking oven as shown in FIG. 16. This allows the cooking pan to keep some 
distance between its bottom surface and the bottom of the cooking chamber 
base. This distance allows for a more complete circulation of air flow. 
In addition to the cooking pan 250, another way to solve the problems 
associated with cooking items which cover most of the rack, such as muffin 
pans, is to use the muffin baking system of the present invention. A 
preferred embodiment of the muffin baking system 270 is shown in FIGS. 
9-15. 
The muffin baking system 270 involves a plurality of spaced cup units 272 
positioned in a frame. Preferred cup units 272 have a flat bottom surface 
274, peripheral walls 276 and peripheral rims 278. The peripheral walls 
276 preferably are created by sloping the bottom surface 274 upwardly and 
outwardly. The bottom surface 274 and the peripheral wall 276 typically 
are one continuous surface. The peripheral rim 278 may be created by 
tightly rolling the edge of the peripheral wall 276. 
There are a number of methods for attaching the cup units 272 to a frame 
for holding the cup units in position. The embodiment 270 shown in FIG. 13 
involves the use of six cup units 272 and a frame system 288. In addition, 
there are a number of frame configurations, holding more or less than six 
cup units. An embodiment having a frame holding twelve cup units is shown 
in FIGS. 5-8. 
FIG. 13 shows a frame having six cup units 272. The cup units 272 may be 
attached to the frame, such as by clamping or by other means including 
welding. Clamping may be done by a number of different methods; the method 
proposed in the embodiment shown is by rolling a tab connected to the rim 
of the cup unit 272. The tab is rolled over the frame segments in at least 
two positions. In other embodiments, positions of tab rolling and frame 
connection may vary depending on the number of cups used and the number of 
annulus shafts used in the frame. 
FIG. 14 shows that the frame system 288 is preferably made up of an outer 
annulus shaft 280, an inner annulus shaft 282, and a plurality of frame 
connectors 286. The frame connectors typically extend radially between the 
inner and outer annulus shafts. Another embodiment allows the frame 
connectors 286 to continue until they meet at the center. The frame 
connectors may be welded together to created a spoked system. The cup 
units 272 may be connected to the outer annulus shaft 280 and the frame 
connectors 286. 
FIGS. 5-8 illustrate an embodiment of the muffin baking system 300 having a 
twelve cup unit. The cup units 302 may be attached in at least two 
positions by welding the cup unit 302 peripheral rim to the frame system 
214. In this embodiment there are 3 annulus shafts, outer 304, middle 306, 
and inner 308. The remainder of the frame system is shown comprised of 
four shafts 310, which may be welded to the annular members. 
In either of the above-mentioned embodiments of the muffin baking system, 
the cup units typically are positioned on the rack 29 inside of the air 
oven 10. The muffin baking system structure allows for cyclonic air to 
more freely circulate throughout the cooking chamber. Air can be drawn up 
through the muffin baking system as required to keep the air heated and 
circulating in its cyclonic pattern. This frame structure eliminates the 
problems associated with muffin pans lacking holes within its structure. 
As with any device that cooks a variety of foods, cleanability is a major 
concern. In most convection ovens, food particles, oil and grease are 
distributed over most interior surfaces of the oven. When these particles 
contact the heater in a convection oven, they burn, causing smoke, odor 
and cleaning problems. With the disclosed air fryer, such problems are 
largely eliminated due to the easy cleanability of the cooking enclosure 
and the design of the heater and its positioning. 
The open coil heater in the disclosed air fryer is positioned directly 
above the blower wheel 43. The blower is fully open at the bottom, but 
also partially open on its top. As a result, the blower draws most of its 
make-up air into its bottom side, but also draws air into its top. This 
causes a portion of the air thrown out from the circumference of the 
blower to reverse direction and be drawn back through the heater 
perimeter, down through the open lower plate of the heater assembly and 
into the semi-open top of the blower wheel. This highly heated air is then 
mixed with the air being drawn in from the bottom of the blower. This 
mixture is then thrown out horizontally into the cooking chamber. This 
configuration provides the following advantage: most particles are unable 
to make the abrupt 180 degree change in direction that the air drawn 
through the heater does. Therefore, the air traveling through the heater 
assembly is virtually free of contamination, while most particles are 
thrown off to the sides and bottom of the cooking chamber, where they can 
easily be cleaned away. As a result of the above, the heater does not 
accumulate food, oil or grease, thereby eliminating the need to clean the 
heater, extending heater element life and preventing smoke or fire hazard. 
Positioning the heater immediately above the blower saves substantial 
space, and allows for the compact design of an easily-removed blower 
assembly. When the assembly is removed, the entire cooking enclosure can 
then be washed in a conventional household dishwasher. The compactness 
allowed by the described heater position leaves more visibility through 
the top wall of the transparent cooking enclosure, providing the user with 
a maximum view of the cooking operation. Due to the blower wheel being 
located directly below the heater assembly, the blower wheel provides 
additional mechanical protection to the heater while further reducing the 
risk of electrical shock to the user. 
The disclosed air fryer is designed to be easily disassembled, allowing the 
entire two piece cooking enclosure to be emersed in water for soaking or 
washing household dishwasher. The enclosure typically is molded of 
low-stick plastic capable of withstanding at least the maximum internal 
operating temperature of 400 degrees F. The blower assembly contains all 
electrical components and easily mounts in the top half of the cooking 
enclosure. The blower assembly is preferably connected to the cooking 
enclosure by way of a bayonet mount, but may also be connected by snapping 
in place by way of metal clips or screwing into place, much like the lid 
on a jar. The blower assembly is dimensioned to fit easily inside the 
cooking enclosure for storage, thereby saving on scarce kitchen storage 
space and reducing shipping and packaging expense. 
Due to the extensive use of plastics and the need to keep assembly 
temperatures comfortable to the touch, internal cooling of the assembly is 
critical. The motor must also be kept within safe operating temperature 
limits. 
To achieve the above objectives, the power unit 13 has been designed to 
draw cool, room temperature air in from directly above the hinge area. 
Drawing air from this point avoids taking in hot air rising off of the 
cooking enclosure. A cooling blade (not shown) located on the same shaft 
as the blower blade 43 serves to draw in this cool air. The cool air is 
pulled through the rectangular segment connecting the motor enclosure to 
the hinge. This "duct" may also house electronic components that are heat 
sensitive or require cooling, such as triacs. From here, the air is drawn 
over the motor, and is then exhausted downwardly through a gap 74 
separating the cooking enclosure and the bottom edge of the blower 
assembly. Here the air serves a valuable function of cooling the cooking 
enclosure plastic at its most vulnerable point, close to the heater 
assembly. 
Any deformation of the blower mount area due to overtemperature trouble 
would render the cooking enclosure useless. Gussets may be molded into the 
blower mount area to act as stiffeners and cooling fins for the plastic. 
When the blower is removed from the cooking enclosure, the user may then 
install optional attachments to convert the air fryer into a steamer, a 
corn popper or other application that would fit the configuration and 
features of the cooking enclosure. 
An important feature fitting the configuration that may be installed when 
the blower is removed is a steam and heat controlling handle. FIG. 1 
illustrates an embodiment of the use of a steam and heat control handle 
100, shown in conjunction with the frying oven. 
The steam control handle interacts in the opening in the upper member 12 of 
the cooking chamber. The steam control handle 100 includes a handle 
portion 112 and a base portion 114. The base portion 114 is designed to 
mount on the upper wall 32 of the cooking chamber. The base portion 
preferably attaches to the upper wall in the same manner as does the 
blower assembly, such as by a bayonet mounting system. The handle portion 
112 has a first riser portion 108 and a second movable riser portion 109. 
The handle portion 112 further includes a transverse portion 110 that 
forms a grippable handle. The sliding portion 109 may be opened so that 
steam entrapped in the cooking chamber may be released through an aperture 
105. 
The sliding portion 109 is movable from a first position, where the sliding 
portion covers the aperture 105, to a second position as shown in FIG. 4, 
wherein a space 106 is formed between the base portion 114 and the sliding 
portion 109. When the handle is so opened, steam is allowed to escape from 
the cooking chamber out through space 106 into the atmosphere. The opening 
is preferably approximately 1-1.2 square inches. When the sliding portion 
is moved so that the aperture 105 is covered, steam rises in the sliding 
portion 109 of the handle. A separation member 118 engages an upper 
portion 104 of the sliding handle 109 to prevent steam from entering the 
hollow chamber of the transverse portion 110 of the handle 100. In this 
manner, even with the sliding portion 109 in a closed position, steam will 
not enter the transverse portion 110 of the handle 100 so that the handle 
still may be held comfortably. 
A ribbed portion 116 of the transverse portion 110 engages a raised end 
portion 117 of the sliding portion 109 to retain the handle in the closed 
or open position. FIG. 4 illustrates that there are three levels at which 
the handle may be retained. In addition, other embodiments may maintain 
more or less than three raised portions for retention of the handle. 
The handle is preferably used to convert the oven from a cooking device to 
a food server. In particular, food may be placed within the oven of FIG. 
19, and cooked as described above. When the food is done, the user simply 
removes the heater unit 13 from the top 12, such as by releasing the 
prefered bayonett mount. Lower frame bracket 14 and upper frame bracket 15 
are preferably removed from the cooking enclosure as well. Handle 118 is 
then attached to top 12, for example by using the preferred bayonet mount. 
The oven is thereby converted to a serving container, which can be carried 
out to the dining table and used to serve the food. 
FIG. 20 shows a preferred embodiment of an oven employing preferred cooking 
racks. In FIG. 20, the oven 10 is shown as including two extension rings 
411 and two extension segments 413. The extension rings 411 are placed 
between the base member 11 and top 12 so as to enlarge the size of the 
cooking chamber. The extension rings are preferably formed as two pieces 
connected together by clips 415. The extension segments 413 are placed 
between the lower frame bracket 14 and upper frame bracket 15 so as the 
accommodate the increased size of the cooking chamber. 
Within the oven 10 of FIG. 20, two racks 420 and 420' can be seen. The rack 
420 is shown in greater detail in FIGS. 22-23. As seen therein, the rack 
420 includes a rack surface 422 and three legs 424. The rack surface is 
preferably made of approximately 13 gauge wire. The rack surface may be 
made up of a plurality of concentric wire rings 423 connected together by 
generally V-shaped wire connectors 425, such as by welding. This 
arrangement provides for a rigid surface upon which food can be placed. 
The legs are also made of wire, preferably a single piece of wire of 
approximately the same thickness as the rack surface. Each of the legs is 
made up two attachment segments 426, two straight segments 428 and a 
connecting segment 430. The attachment segments 426 are fixedly attached 
to the rack surface, preferably by welding. The straight segments 428 
extend downwardly, preferably perpendicularly, from the rack surface. 
The connecting segments 430 connect the two straight segments 428 together 
and preferably include a plurality of U-shaped portions 432. The U-shaped 
portions 432 are located at varying distances away from the rack surface 
so as to provide adjustability to the racks. As shown in FIGS. 20 and 21, 
the U-shaped portions may rest on the wire of cooking rack 29. The height 
to the rack 420 above cooking rack 29 can be adjusted by varying which set 
of U-shaped portions are placed on the cooking rack 29. 
The rack 420' shown in FIG. 23A is identical to that shown in FIG. 23, 
except that the straight segments 428' are longer than those of FIG. 23. 
Likewise, the rack 420' shown in FIG. 23B is indentical to the other 
disclosed racks, except that the straight segments 428' are even longer. 
For the rack 420, the range of adjustability may preferably be from about 
3/4" to 2". The rack 420' is repreably adjustable from about 33/4" to 5". 
The rack 420" is preferably adjustable from about 61/4" to 71/2". 
Together, these three racks provide for a great range of adjustability in 
the placement of food within the oven. 
As shown in FIG. 20, the racks can be stacked so that more than one rack 
can be used at a time. In FIG. 20, the lower rack 420' is placed on the 
base rack 29, while the upper rack 420 is placed on the rack 420'. 
Alternatively, according to the present rack invention, it is also 
possible, for example, to place both racks 420 and 420' directly on the 
base rack 29. 
In addition to providing a surface on which food can be placed, the racks 
420, 420' and 420" also can serve as hold down racks to hold down food 
placed underneath the racks. The oven shown in FIG. 20 may develop very 
high speed air movement within the oven. This high air speed can result on 
the food being blown off the rack. By placing a rack 420 over the food 
which has been placed on a lower rack, the problem of blowing food off the 
rack is greatly reduced. 
The foregoing constitutes a description of various preferred embodiments. 
Numerous changes to the preferred embodiments are possible without 
departing from the spirit and scope of the invention. Hence, the scope of 
the invention should be determined with reference not to the preferred 
embodiments, but to the following claims.