Cabinet-style apparatus for transferring heat to food and cooling food

The present invention is directed to a vertical cabinet having the dual function of heating or cooling food articles within the cabinet. The cabinet comprises a plurality of removable, vertically spaced-apart support shelves of a conductive material for supporting food articles. One aspect of the invention provides for heating and cooking of food articles by circulating a thermal liquid fluid through a heating channel having a serpentine configuration in each shelf. Each shelf has quick-disconnect couplings. Another aspect of the invention provides for cooling and refrigeration of food articles by circulating a chilled fluid transfer media from a cooling unit connected to the vertical cabinet to the shelves of the cabinet.

TECHNICAL FIELD 
The present invention relates generally to an apparatus having the dual 
function of heating or cooling food. One aspect of the invention relates 
generally to ovens for cooking and heating foods, and also for maintaining 
food cooked by such ovens at constant temperatures. More particularly, 
this aspect of the invention relates to an oven for providing a 
combination of convection and conduction cooking and heating through an 
individually thermalized shelf. The combined convection/conduction heating 
is provided by passing thermal energy through a heating channel having a 
serpentine configuration. 
Another aspect of the invention relates to an apparatus having the function 
of conduction refrigeration which converts a temperature transfer fluid to 
a cooling media cycle. In order for the cabinet-style apparatus of the 
present invention to be suitable for heating or cooling of food, a 
refrigeration/cooling assembly means is used with the apparatus. The 
cooling assembly means comprises a heating/cooling selector attachment 
unit attached directly to the back manifold of the apparatus and a 
refrigeration/cooling unit connected to the attachment unit. Thus, 
conduction cooling rather than conventional convection cooling is 
achieved. 
BACKGROUND OF THE INVENTION 
Ovens for cooking and heating foods are well known in the art. Some of 
these ovens facilitate convective cooking in which heat is indirectly 
transferred to the food through the air between the heat source and that 
food. Other ovens facilitate conductive cooking where the food is heated 
by direct contact with a surface at an elevated temperature. 
A few ovens provide combinations of convective and conductive cooking. U.S. 
Pat. No. 4,224,862 discloses a shelf and serpentine, widely spaced-apart 
hollow tubing within that shelf for the transport of heating fluids. 
Trays or shelves for a hot food cabinet are disclosed in FIGS. 4 and 5 of 
U.S. Pat. No. 3,030,486. This patent further discloses electric heating 
elements and steam as a heating medium. 
A prior experimental apparatus developed by the inventor of the present 
invention features a vertical cabinet having a plurality of individually 
thermalized, vertically spaced-apart rectangular support shelves. These 
shelves are made from a heat conductive material. Specifically, the 
shelves are made from two aluminum sheets of differing thickness. The 
thicker sheet, having a thickness of about 40/1000th inch, defines a top 
surface of the shelf. The thinner sheet, having a thickness of about 
30/1000th inch, defines a bottom surface. The two shelves are roll-bonded 
together in a manner that forms by expansion a serpentine fluid channel in 
the bottom surface. A heated fluid may be passed through the channel by a 
fluid inlet and outlet positioned along one width side of the shelf. As a 
result of such inlet positioning, the serpentine channel undulates in a 
manner parallel to the shelf width. 
While the foregoing prior art device was an improvement over prior art 
heating and holding cabinets, it was determined that the top surface sheet 
was insufficiently thick. This caused the top surface to become uneven and 
indented during the roll-bonding process. As a result, the top surface had 
high and low spots which prevented even and uniform conductive 
thermalization of a food product placed thereon. In addition, the 
undulation of the serpentine channel in a manner generally parallel to the 
width of the shelf did not efficiently and uniformly thermalize the 
complete surface area of the top surface of the shelf. Unthermalized zones 
on the top surface thereby resulted. 
In addition, refrigeration technology is known in the art. A prior art 
device that provides for both heating and refrigeration features is 
disclosed in U.S. Pat. No. 4,235,282 to de Filippis et al. This patent 
discloses a tray cabinet comprising a refrigerating device to pump 
refrigerated air into a set of shelves for receiving removable trays and a 
means for individually heating restricted sections in the trays. However, 
the tray cabinet of this patent is cooled by convection refrigeration 
rather than the more efficient conduction refrigeration of the present 
invention. 
Another prior art device that provides for both heating and refrigeration 
features is disclosed in U.S. Pat. No. 4,346,756 to Dodd et al. This 
patent discloses an apparatus for selectively heating an individual food 
item in a refrigerated environment. Again, however, the apparatus of this 
patent is cooled by convection refrigeration rather than the conduction 
refrigeration of the present invention. 
Other prior art devices that include heating and cooling features are 
disclosed in U.S. Pat. Nos. 3,205,033 to Stentz; 3,965,969 to Williamson; 
3,982,584 to Spanoudis; and 4,103,736 to Colato et al. These prior art 
devices suffer some of the same deficiencies as de Filippis et al. and 
Dodd et al. 
The above problems of prior art heating and holding cabinets and heating 
and cooling cabinets are addressed by the development of the present 
invention. The present invention is an improvement over the prior art and 
overcomes the problems associated with the prior art. The apparatus of the 
present invention provides consistent and superior heating and cooling 
transfer efficiencies because the apparatus utilizes principles of 
conduction heat/coolant transfer as opposed to using only the conventional 
convection heating/cooling technologies in common practice today. 
SUMMARY OF THE INVENTION 
Generally, the present invention comprises a vertical cabinet for 
transferring heat to food articles within that cabinet, or in the 
alternative, cooling food articles within that cabinet. The cabinet 
includes a plurality of vertically spaced-apart, individually support 
shelves which can be thermalized or cooled, which are made from a heat or 
cold conductive material, and which support food articles. Integrally 
constructed within each shelf is a channel having a serpentine 
configuration for heating and cooling. 
In the cabinet is activated for heating, an energy circulation media 
element or fluid transfer media is carried at an upper portion of the 
cabinet for passing thermal energy through the serpentine channel. Inlet 
and outlet connectors on each shelf facilitate passage of thermal energy 
into and out of the serpentine channel. Supply conduits are provided 
within the cabinet for transferring the thermal energy from the energy 
circulation element to the thermalizing channel. Return conduits within 
the cabinet facilitate return of the thermal energy to the energy 
circulation element. Thus, it is among the primary aspects of the present 
invention to provide an apparatus that uses conduction heating by passing 
thermal energy through a heating channel having a serpentine 
configuration. 
It is another aspect of the present invention to provide an apparatus that 
uses conduction cooling which is achieved by using a refrigeration/cooling 
assembly means with the cabinet-style apparatus of the present invention. 
The cooling assembly means comprises a heating/cooling selector attachment 
unit attached to the back manifold of the cabinet-style apparatus and a 
refrigeration/cooling unit connected directly to the attachment unit via 
an input pipe and an output pipe. The embodiment comprising a separate 
external attachment unit connected to the back of the cabinet and the 
separate remote cooling unit are used so that the functioning of the 
components and connections at the top of the cabinet-style apparatus are 
not substantially disrupted. The attachment unit comprises a plurality of 
valves and pipes that divert the stream of flow of a fluid transfer media 
either from its cooled state from the cooling unit into the apparatus or 
from its heated state from the heating unit/reservoir into the apparatus. 
The cooling unit output pipe transfers the fluid transfer media from the 
remote cooling unit, passes the fluid through the attachment unit, and 
introduces the fluid into the plates or shelves of the cabinet apparatus 
in order to bring about a preferred temperature equilibration. The cooling 
unit input pipe transfers the fluid transfer media back into the cooling 
unit after it has circulated through the shelves and apparatus so that it 
can be re-cooled in the cooling unit. The refrigeration/cooling unit 
itself comprises a heat exchanger, compressor, condenser, circulating pump 
and motor, inline filter, and a pressure sensing unit. A heating/cooling 
selector switch is located on the back of the cabinet so that a user can 
manually activate either the heating or cooling mechanisms. When the 
cooling mechanism is activated, a control box housed in the cooling unit 
is also activated to start the components of the cooling unit into 
operation. Thus, the attachment unit and cooling unit are operated both 
manually and electronically. 
The conduction cooling mechanism of the present invention achieves targeted 
internal temperature equilibration of food articles within 3 to 5 times 
shorter duration than those required under conventional refrigeration 
techniques. The conduction cooling mechanism also readily permits precise 
targeting of equilibrated temperatures, i.e. solid or liquid articles may 
be placed in the apparatus for "cooling" (with an equilibration goal of 40 
degrees F. ), "chilling" (33 degrees F. equilibration), or 
"super-chilling" (29 degrees F. equilibration) operations. 
With each of the selected temperature ranges, the fluid transfer media, 
which is circulated through the unit's shelves in order to bring about the 
preferred temperature equilibration, retains its fluid viscosity at a 
level suitable for continuous recirculation through the closed-loop or 
serpentine configuration system. 
Additional aspects and features of the present invention will appear from 
the following description in which the preferred embodiments are set forth 
in detail in conjunction with the accompanying drawings.

DETAILED 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 
preferred embodiments of the invention with the understanding that the 
present disclosure is to be considered as an exemplification of the 
principles of the invention and is not intended to limit the broad aspects 
of the invention to the illustrated embodiments. 
Referring now to the drawings, FIGS. 1-5 disclose one embodiment of the 
present invention comprising a vertical cabinet 10 for transferring heat 
to food, such as poultry or meat products, and to farinaceous or starch 
containing products. Typically, these cabinets are made of stainless steel 
or another lasting, noncorroding and attractive metal. To reduce energy 
consumption and lower the danger of burns to those who may inadvertently 
contact its exterior, heat loss through the walls of each cabinet 10 is 
reduced by insulating those walls. 
A plurality of vertically spaced-apart, rectangularly-shaped support 
shelves having substantially flat top and bottom surfaces are located in 
the vertical cabinet 10. Cabinet 10 may typically include ten or more of 
these support shelves. In FIGS. 1 and 2, the topmost three support shelves 
within the cabinet 10 are exemplified by reference numerals 12, 14 and 16. 
Each of the support shelves shown in FIG. 1 is removably secured to the 
walls of the cabinet 10 and is sufficiently sturdy to support as much as 
50 pounds of food articles, such as poultry, fish or meat, within the 
cabinet 10. The support shelves 12, 14 and 16 are each made of a heat 
conductive material, preferably aluminum. 
A pair of doors 18 and 20 provide access to the shelves 12, 14 and 16. 
These doors are hinged and are retained in place with magnetic catches 22 
and 24, respectively. A control panel 26 at the top of the cabinet 10 
enables the operator to control the temperatures of each of the individual 
shelves in that cabinet 10. 
A centrifugal pump 28 is provided at the upper end of the cabinet 10 for 
circulating a heated fluid through the shelves. The pump used in this 
embodiment is manufactured by March Manufacturing of Glenview, Ill., Model 
BC-4K-MD. Adjacent pump 28 is a reservoir 30 which also includes a heating 
element for initially heating the fluid and for reheating the fluid after 
its return from the shelves. This reservoir/heating element 30 is 
available from Watlow. Preferably, as may be seen in FIG. 2, reservoir 30 
is coupled to a pressure relief cap 33 (Hydro Craft, Detroit, Mich.). A 
ventilation fan 31 maintains pump 28 and reservoir 30 at acceptable 
operating temperatures. The pressure relief cap 33 is necessary to vent 
any excess pressure from the system. Such excess pressure can occur from 
the vapor pressure of heated water circulating through the shelves. 
FIGS. 3 and 4 disclose the structure of the shelves 12 utilized in the 
heated fluid embodiment of the present invention. Shelf 12 is manufactured 
from aluminum and is formed by bonding two sheets together by use of a 
roll-bonding technique. One sheet defines a top surface 32 of shelf 12 and 
the bottom sheet defines a bottom surface 34 of shelf 12. The sheet used 
to form top surface 32 is thicker than the sheet used to form bottom 
surface 34. Preferably, the ratio of top surface sheet thickness to bottom 
surface sheet thickness should be at least 1.75:1 and, preferably, about 
2.25:1. A top/bottom sheet thickness ratio of 2.25:1 dictates a top 
surface sheet thickness of 90/1000ths inch and a bottom surface sheet 
thickness of 40/1000ths inch. Such highly disparate thicknesses between 
top surface sheet thickness relative to bottom surface sheet thickness has 
been found necessary in order to assure that top surface 32 has an even 
surface from edge to edge with no high or low spots caused by the 
roll-bonding process. 
As disclosed in FIGS. 3 and 4, shelf 12 becomes thermalized by passage of a 
heating fluid through a serpentine heating means 36 comprising a 
serpentine channel which undulates along bottom surface 34. Unlike the 
aforementioned prior art device, such undulations are generally parallel 
to the length of rectangular shelf 12. Serpentine channel 36 generally has 
inner dimensions approximating 1 inch. Heating fluid is passed through 
serpentine channel 36 through an inlet connector 38 and an outlet 
connector 40 along a rear side of shelf 12. 
Referring again to FIGS. 3 and 4, the shelf 12 has a width and a length. 
The length of the shelf is the longer of the two dimensions, and is that 
dimension along which inlet connector 38 and outlet connector 40 are 
secured. The width of the shelf is the shorter of the two dimensions and 
is that dimension in FIGS. 3 and 4 to which lead line 12 is directed. As 
may be appreciated from FIG. 4, the great majority of the serpentine 
channel 36 is parallel to the length of the shelf 12. In fact, accounting 
for only straight portions and excluding the 90-degree or 180-degree 
bends, approximately 90 percent of the serpentine channel 36 is parallel 
to the length of the shelf 12. As compared to shelves which have much of 
their channels parallel to their widths, forming a shelf where the great 
majority of the serpentine channel is parallel to the length of the shelf 
12 increases its rigidity. It is believed that significant increases in 
the rigidity of shelves occurs where 65 percent or more of the straight 
portions of the channels are parallel to the length of the shelf. 
Unlike prior art devices in which inlet and outlet connectors are 
positioned along a width edge of a rectangular shelf, inlet and outlet 
connectors 38 and 40 are positioned along the rear length side of shelf 
12. This may be seen in FIG. 4. This enables the majority of the 
serpentine channel to run parallel to the length of the shelf, and 
increases heating efficiency by causing a higher percentage of top surface 
32 to be heated. This also minimizes unheated zones along top surface 32 
and assures uniform heating Of all food product placed on top surface 32. 
Shelf 12 and serpentine channel 36 are formed by a roll-bonding process. 
This process is generally known in the aluminum forming art, and includes 
photographically etching a serpentine pattern on one surface of the bottom 
sheet. This pattern will define serpentine channel 36. Next, the top and 
bottom sheets are rolled together under exceedingly high pressure which 
bonds the top and bottom sheets together, but does not bond portions of 
the surface of the bottom sheet on which the serpentine pattern is 
photographically etched. As a result, a serpentine channel is partially 
formed which can be completed by introduction of high air pressure into 
channel 36 which causes serpentine channel 36 to inflate into a full 
three-dimensional shape. 
As also disclosed in FIGS. 3 and 4, shelf 12 includes downwardly turned 
flanged edges along both width sides of shelf 12 and along the length side 
of shelf 12 opposite from inlet connector 38 and outlet connector 40. As 
disclosed in FIG. 1, flange edges 42 engage support rails 44 to support 
the shelves within vertical cabinet 10. 
Also disclosed in FIGS. 3 and 4 are a pair of upwardly directed retainers 
46 formed along a rear edge of shelf 12. Retainers 46 permit trays of food 
product to be properly positioned on top surface 32. 
Heated fluid is moved from the pump 28 and heating reservoir 30 through a 
series of conduits along the frame of the cabinet. As best disclosed in 
FIGS. 2 and 5, a supply conduit 48 within the cabinet 10 feeds the heated 
fluid to the inlet connector 38 on each shelf. Parallel to supply conduit 
48 is a fluid return conduit 50. A bottom portion of conduit 48 is 
connected to a bottom portion of return conduit 50 by means of linking 
conduit 52. Linking conduit 52 returns to fluid pump 28 and heating 
reservoir 30 whatever portion of the heated fluid did not pass through 
channel 36 of the shelves. 
There are substantial advantages in placing the heating reservoir 30 at the 
top of the cabinet 10. The shelves in cabinet 10 are filled with water 
during operation. When the operation is ended, the pump 28 is shut down. 
It was found that water in the shelves from a cabinet with a 
bottom-mounted reservoir would tend to drain into that reservoir. 
Consequently, there was an increased tendency for air to enter and become 
entrapped in those shelves. Placing the reservoir 30 at the top of the 
cabinet 10 has been the solution to this problem. With the reservoir 30 at 
the top of cabinet 10, it is impossible upon system shutdown for water 
from the shelves to drain into the reservoir. Rather, placement of this 
reservoir 30 at the top of cabinet 10 results in full shelves at all times 
absent of any air entrapment. 
Inlet tubing 54 removably couples the inlet connector 38 to supply conduit 
48. Outlet tubing 56 removably couples the outlet connector 40 to return 
conduit 50. As a result of such coupling, each shelf is independently 
thermalized. 
The preferred heating fluid or fluid transfer media includes a solution of 
50 percent water and 50 percent propylene glycol (DOWFROST.RTM. HD, Dow 
Chemical, USA). It is understood that if the heater 30 portion of the unit 
is not being used, and if instead the cooling unit and attachment unit are 
used, the fluid transfer media may function as a cooling fluid, thereby 
converting cabinet 10 into a conduction refrigeration unit. 
FIGS. 6-8 disclose another embodiment of the present invention which 
utilizes electrical heating rather than fluid heating shelf thermalizing 
means. As shown in FIG. 6, this embodiment also includes a vertical 
cabinet 58 and a plurality of vertically spaced-apart, individually heated 
support shelves, such as shelves 60, 62 and 64, carried within the 
vertical cabinet for supporting foods. Like the embodiment of FIGS. 1-5, 
the support shelves of this embodiment are made of a heat conductive 
material. The heat conductive material in this embodiment is stainless 
steel. 
Thermal energy for shelves 60, 62 and 64 is provided by an electrical power 
source 66 at the upper end of the cabinet 58. Power source 66 is a 
conventional alternating current device which can circulate electrical 
current through conducting elements in the shelves. 
As may be seen in FIGS. 7 and 8, a serpentine electrical power conduit 68 
is enclosed entirely within shelf 60, and comparable serpentine channels 
are enclosed in each of the other shelves. As may be seen in FIG. 7, the 
area of this serpentine power conduit 68 is in excess of one-half of the 
area of the shelf 60. In addition, because it is entirely enclosed by the 
shelf construction, serpentine conduit 68 provides for both uniform 
conductive heating for the top of the shelf and some convective heating 
for food products carried on below-positioned shelves. The enclosed 
serpentine conduit 68 also assures uniform heating of at least the upper 
surface of each shelf, and thereby eliminates unintended temperature 
gradients along the surface of the shelf. 
Preferably, serpentine conduit 68 is a metallic heating conductor. The 
conductor material may be a resistance heating alloy, such as copper, 
brass or aluminum. Typically, the material is very thin, on the order of 
10 to 100 micrometers. 
As disclosed in FIG. 8, an insulating material 70, such as polycarbonate, 
overlays the serpentine heating conduit 68 to form a heating foil 72. 
Insulating material 70 peeled away should be quite thin, on the order of 
3/32 to 1/8 inch. The insulating material 70 may also be selected from any 
suitable group of insulators, including polyvinyl chloride, polyester, 
silicone rubber and micanite. 
Heating foil 72 includes at least one current inlet connector 74 and one 
current outlet connector 76 through which alternating current enters and 
leaves the conduit 68 of shelf 60. The location of inlet connector 74 and 
outlet connector 76 can vary and is a matter of design choice largely 
dependent on the particular configuration of the serpentine heating 
element. Electrical supply wiring 78 within the cabinet transfers the 
electrical current from the electrical power source 66, while electrical 
ground wiring (not shown) within the cabinet returns the electrical 
current from the serpentine heating conduit 68. 
Finally, cabinet 58 includes first electrical junction means for securing 
the inlet connector 74 to the electrical supply wiring and second 
electrical junction means for securing the outlet connector 76 to the 
electrical ground wiring. In this way, conduit 68 can be removably plugged 
into the electrical supply wiring 78 and the ground wiring. 
FIGS. 9-13 show a liquid heated embodiment that provides for quick-connect 
and quick-disconnect of shelves to the frame of the vertical 
heat-transferring cabinets. Particularly, FIG. 9 depicts, in a partial 
section side elevational view, a cabinet-style heat transferring apparatus 
80 like that shown an FIG. 2. This FIG. 9, however, shows in greater 
detail an example of a particular type of quick-release connector, 
hereinafter occasionally referred to as "quick-release fittings" or 
"quick-connectors." 
The cabinet 80 of FIG. 9, like that of FIG. 2, includes a 
vertically-disposed fluid supply conduit 82 and a parallel fluid return 
conduit 84. As with the conduits of the cabinet of FIG. 2, these fluid 
supply conduits 82 and return conduits 84 supply fluid to the shelves 86. 
Shown on fluid supply conduit 82 and fluid return conduit 84 are the male 
portions 88 of quick-connect fittings 90. Fluid from the fluid supply 82 
and return 84 conduits are fed to and removed from the cabinet shelves 86, 
respectively, through the male portions 88 of these quick-connect fittings 
90. The fluid supply conduit 82 is connected to the discharge side of pump 
92, while the fluid return conduit 84 is connected to the suction side of 
pump 92. 
The male portion 88 of quick-connect fitting 90, and the quick-connect 
fitting 90 itself, may be seen and best understood by reference to FIGS. 
11-13. In these Figures, a male portion 88 of fitting 90 is shown in its 
position secured to fluid return conduit 84. The male portion is 
physically secured to a wall 94 of fluid return conduit 84 with a pliable, 
rubber-like grommet 96. This grommet 96 also provides a fluid-tight seal 
of the hole drilled into the fluid return conduit 84 which permits entry 
of the male portion 88 of fitting 90. 
Fitting 90 also includes an inner fluid passage 98 disposed along the 
central axis of the male portion 88. In the embodiment of FIGS. 11-13, 
this inner fluid passage 98 has three portions. When viewed from left to 
right in FIGS. 11-13, these three portions have increasing diameters. 
The male portion 88 of fitting 90 also includes a rigid, hollow polymeric 
tip 100. Each tip 100 is axially disposed in a tip guide 102 segment at 
the distal end of the male portion 88. Circumscribing this tip guide 102, 
and housed in a groove along the exterior, is an O-ring 104. 
The tip 100 is indirectly secured at one of its ends to a spring 106. As 
may be seen from FIG. 11, the other end 108 of tip 100 extends outwardly 
from the male portion 88 of fitting 90, and is visible when the male 
portion 88 is separated from the female portion 110. In the position of 
the components shown in FIG. 11, the spring 106 biases a gasket 112 to 
create a fluid-tight seal between inner fluid passage 98 and the hollow 
portion of tip 100. 
FIG. 12 depicts the female portion 110 of fitting 90 being placed into 
initial engagement with the male portion 88 of that fitting 90. Female 
portion 110 of fitting 90 includes a spring-biased, hard polymeric disc 
114. Disc 114 is not solid, but rather has openings permitting fluid flow 
through that disc 114. One end of the spring 116, which biases this disc 
114, abuts against the far end of a first fluid chamber 118. 
The disc 114 is secured to one end of a pin 120. An O-ring 122 is secured 
to the other end of this pin 120. In the positions of FIGS. 11 and 12, 
this O-ring 122 separates first fluid chamber 118 from second fluid 
chamber 124. As may be seen in FIG. 13, however, upon abutment of disc 114 
against the end of tip guide 102, disc 114 is pushed to the right, 
compressing spring 116 and moving the pin 120 and O-ring 122 to the right. 
This effectively opens first fluid chamber 118 to second fluid chamber 
124, permitting fluid flow through the entire fitting 90. In this way, 
fluid can pass to or from the fluid return conduit 84, the fitting 90, and 
the inlet 38 or outlet connectors 125 of the shelves, such as shelf 86. 
As may best be seen in FIG. 11, a threaded end cap 126 is secured to one 
end of the female portion 110 of fitting 90. A compression ring 128 is 
captured within this threaded end cap 126. When the present invention is 
fully assembled and in its normal operational mode, and as stated above, 
the male portion 88 of fitting 90 is secured to the fluid return conduit 
84. In addition, the female portion 110 of fitting 90 is normally secured 
to an inlet 38 (not shown) or outlet connector 125 of shelf 86. This 
securement is effected, for example, by inserting outlet connector 125 
through threaded end cap 126 and compression fitting 128, and then 
threading that end cap 126 onto the appropriate end of the female portion 
110 of fitting 90. In FIG. 12, both portions of fitting 90 are shown in 
their normal operational mode. In particular, male portion 88 of fitting 
90 is secured to fluid return conduit 84. Female portion 110 of fitting 90 
is secured to the outlet connector 125 with threaded end cap 126 and its 
compression fitting 128. 
Female portion 110 of fitting 90 includes a flared end 130. As may be seen 
in FIG. 12, this flared end 130 permits the female portion 110 to be mated 
with the male portion 88 at an angle from the horizontal. This attribute 
is important for ease of installation. As will be explained below, the 
ability to install shelf 86 at an angle from the horizontal also 
facilitates the operation of means provided for tightly securing together 
male 88 and female 110 portions of fitting 90. 
With the above description of the components shown in FIGS. 9-13 as 
background, the operation of the quick-connectors can be readily 
understood. As discussed above, flared end 130 permits an angled 
engagement of shelf 86, and female portion 110 to which shelf 86 is 
secured, with male portion 88. This may best be seen in FIG. 12. Spring 
106 in male portion 88 is less stiff than spring 116 in female portion 
110. As a result, upon the contact of tip 100 with disc 114 as shown in 
FIG. 12, only spring 106 compresses. As a result, tip 100 withdraws into 
tip guide 102 and gasket 112 is moved away from its seat. Moreover, 
orifice 132 in the side wall of tip 100 is moved into the inner fluid 
passage 98. Fluid within that passage 98 may then pass through orifice 132 
into the interior of the hollow tip 100. 
As the female portion 110 is pushed into closer engagement with the male 
portion 88, tip 100 disappears entirely from view within the tip guide 
102, and the end of tip guide 102 engages disc 114. Tip guide 102 pushes 
the disc 114, spring 116 and pin 120 to the right, releasing O-ring 122 
from its seat. As a result and as may be seen in FIG. 13, fluid can pass 
between the first fluid chamber 118 and the second fluid chamber 124. 
As discussed above, the present device includes means to ensure that the 
shelf 86 and fitting 90 remain in the essentially locked position of FIG. 
13. These means are shown in FIG. 9, and comprise a plurality of generally 
horizontal bar-like or dowel-like devices 134. To install shelf 86 into 
cabinet 80, the shelf 86 is held at an angle to the horizontal. The shelf 
86 and its female portion 110 are pushed towards male portion 88 of 
fitting 90 until a butt end 136 of the female portion 110 engages a butt 
end 138 of the male portion 88. The shelf 86 is then lowered into the 
horizontal position shown in FIG. 9. In this horizontal position, the 
dowel 134 is lodged between or snaps into a slot 136 formed or fabricated 
along the underside of the shelf. In this way, the shelf 86 is held in the 
position shown in FIG. 9, notwithstanding the pressure of springs 106 and 
116. 
When shelf 86 is in the position shown in FIG. 9, the male 88 and female 
portions 110 of fitting 90 are in the positions shown in FIG. 13. This 
FIG. 13 depicts the present device in a state where there is an open fluid 
path from the fluid supply 82 or return conduit 84 through fitting 90 and 
then through the inlet or outlet 125 connectors of the shelf 86. 
Significantly, these quick-connectors 90 also prevent air from entering the 
system when the shelves 86 are removed from cabinet 80. When the shelves 
86 are removed from cabinet 80, the female portion 110 of connector 90 is 
separated from the male portion 88 of connector 90. This is depicted in 
FIG. 11. As may be seen from the positions of the components of connector 
90 in FIG. 11, the fluid in both return conduit 84 and inner fluid passage 
98 is trapped by gasket 112, and cannot move into rigid, hollow polymeric 
tip 100. In addition, the fluid in shelf 86, outlet connector 125, and 
second fluid chamber 124 is trapped by O-ring 122, and cannot move into 
first fluid chamber 118. Thus, a shelf 86 may be removed from the cabinet 
80 without loss of fluid from either the shelf 86, or from the conduit 84 
and male portion 88, even when the pump 92 is operating or when the shelf 
and conduits 82 and 84 are filled with water. In this way, the 
quick-connector 90 also ensures that air will not be drawn into the system 
when a shelf 86 is removed from cabinet 80. 
FIG. 14 shows a perspective view of the conduction refrigeration/cooling 
assembly means 140 that can be used with the cabinet 10 of FIGS. 1-5. This 
cooling assembly means 140 provides for the conversion of the 
cabinet-style apparatus from a heating system and oven unit to a cooling 
system and refrigeration unit. A heating/cooling selector attachment unit 
150 is connected to the back manifold of the vertical cabinet 10 of FIG. 
5. A refrigeration/cooling unit 180 is positioned adjacent cabinet 10 and 
connected to the attachment unit 150 via an output pipe unit 156 and an 
input pipe unit 158. In order that the functioning of the components and 
connections at the top of the cabinet-style apparatus are not 
substantially disrupted, the embodiment encompassing a separate external 
attachment unit connected to the back of the cabinet and a separate remote 
cooling unit is used. However, the use of a cooling assembly with the 
cabinet 10 of the present invention is not limited to the disclosed 
embodiment. While the embodiment shown uses a separate cooling assembly 
140 with the cabinet 10, it is appreciated that the cooling assembly 140 
and cabinet 10 can also be incorporated into a single mechanism or 
machine. 
The conduction cooling assembly 140 used in conjunction with the cabinet 10 
achieves targeted internal temperature equilibration of food articles, 
within 3 to 5 times shorter duration than those required under 
conventional refrigeration techniques using convection cooling which blows 
cold air directly on the food articles. FIG. 20 illustrates a graph which 
compares the relation of the cooling time and temperature between items 
cooled in the apparatus of the present invention using conduction 
refrigeration and items cooled using conventional convection 
refrigeration. As can be seen from the results illustrated on the graph, 
items that are cooled in the apparatus of the present invention are cooled 
to a certain temperature at a much faster rate using conduction 
refrigeration than items cooled by conventional convection refrigeration. 
The conduction cooling assembly 140 also provides for precise targeting of 
the equilibrated temperatures. The fluid transfer media, which is 
circulated through shelves 12 of cabinet 10 in order to bring about the 
preferred temperature equilibration, retains its fluid viscosity at a 
level suitable for continuous recirculation through the closed loop system 
as discussed above in conjunction with the heating system. The cooling 
assembly 140 utilizes conduction refrigeration technology rather than 
conventional convection refrigeration. 
FIG. 15 shows the heating/cooling selector attachment unit 150 connected to 
an upper back portion of cabinet 10. The attachment unit 150 comprises a 
plurality of valves and pipes that divert the stream of flow of the fluid 
transfer media either from its cooled state from the cooling unit 180 into 
the cabinet 10 or from its heated state from the heating element/reservoir 
30 (FIG. 2) into the cabinet 10. A first temperature valve 152 is 
connected to connector pipe sections 154 which are adjacent each side of 
the first temperature valve 152. One of the connector pipe sections 154 is 
connected at its end portion to an output pipe unit 156. The other 
connector pipe section 154 is connected at its end portion to an input 
pipe unit 158. The first temperature valve 152 is an electrically 
activated solenoid valve controlled by a control box 244 (see FIG. 16) 
located in the refrigeration/cooling unit 180. When the cooling mode is 
activated, the first temperature valve 152 closes, and the chilled fluid 
transfer media which is transported from the cooling unit 180, is diverted 
to the inlet connectors of the shelves 12 and into the serpentine channels 
of shelves 12 of the cabinet 10. When the heating mode is activated, the 
first temperature valve 152 opens so that the heated fluid transfer media 
flows from a heating element/reservoir 162 through the connector pipe 
sections 154, through a series of conduits and inlet connectors along the 
frame of the cabinet 10, and into the serpentine channels of shelves 12 
for heating. 
The output pipe unit 156 introduces and transfers chilled fluid transfer 
media from the remote cooling unit 180 into the attachment unit 150. A 
cabinet circulating pump 160, like the centrifugal pump shown in FIG. 2, 
is provided on the top surface of the cabinet 10 and is only used to 
circulate the fluid transfer media when the apparatus is in the heating 
mode. The pump 160 used is manufactured by March Manufacturing of 
Glenview, Ill., Model BC-4K-MD. Adjacent pump 160 is a reservoir/heating 
element 162 which is also only used when the apparatus is in the heating 
mode. The heating element 162 heats the fluid transfer media before it 
flows into the serpentine channels of the shelves 12 and reheats the fluid 
transfer media after its return from the shelves 12. The reservoir/heating 
element 162 is like the heating element shown in FIG. 2 and is available 
from Watlow. The cabinet circulating pump 160 and heating element 162 are 
not used when the apparatus 10 is in the cooling mode. 
Upon activation of the cooling function, the first temperature valve 152 
closes and the chilled fluid transfer media that flows from the cooling 
unit 180 bypasses the connector pipe sections 154 and the first 
temperature valve 152 and flows into the shelves 12 of cabinet 10 to begin 
the conduction cooling of the shelves 12. The cooling unit input pipe 158 
transfers the fluid transfer media back into the cooling unit 180 after it 
has circulated through the shelves 12 and apparatus 10 so that it can be 
re-cooled in the cooling unit 180. 
A second temperature valve 164 is located below and at an angle from the 
first temperature valve 152. The second temperature valve 164 is connected 
to the output pipe unit 156. A third temperature valve 166 is located 
directly across from the second temperature valve 164 and below and at an 
angle from the first temperature valve 152. The third temperature valve 
166 is connected to the input pipe unit 158. When the cooling mode is 
activated, the second temperature valve 164 and the third temperature 
valve 166 open to divert the flow or circulation of the chilled fluid 
transfer media from the cooling unit 180 into the shelves 12. When the 
heating mode is activated, the second temperature valve 164 and the third 
temperature valve 166 close, as the flow of the heated fluid transfer 
media is diverted by the first temperature valve 152. Both the second 
temperature valve 164 and the third temperature valve 166 are electrically 
activated solenoid valves controlled by the electric components in the 
control box 244 of the cooling unit 180. 
Also included in the attachment unit 150 is a first gate valve 168 and a 
second gate valve 170 positioned below the second temperature valve 164 
and the third temperature valve 166, respectively. The first gate valve 
168 is also connected to the output pipe unit 156, and the second gate 
valve 170 is also connected to the input pipe unit 158. Both gate valves 
168, 170 are open when the cooling unit 180 is connected to the cabinet 10 
and are closed when the cooling unit 180 is disconnected from the cabinet 
10. Thus, the cooling unit 180 can be easily disconnected from the cabinet 
10 without disrupting the attachment unit 150 and cabinet 10 components 
and the heating capability of the cabinet 10. 
A temperature selector switch 172 is located on the-back panel of cabinet 
10. When the switch 172 is in the down position, the cooling mode is 
activated. When the switch 172 is in the up position, the heating mode is 
activated. 
FIGS. 16-18 disclose an embodiment of the cooling unit 180 of FIG. 14. The 
high-speed conduction chilling apparatus or cooling unit 180 can easily be 
used with the cabinet-style apparatus 10 shown in FIG. 1 to convert the 
cabinet 10 from a heating system into a refrigeration system. An 
embodiment of the cooling unit 180 that can be used comprises a separate 
remote unit containing the main components of an insulated heat 
exchanger/evaporator 200, a compressor 210, a fan cooled condenser 212, an 
inline filter 220, and a cooling unit circulating pump 224 and pump motor 
228. These main components, along with other conventional refrigeration 
technology components, are enclosed in a box-like housing 182. The cooling 
unit 180 has four swivel wheels and can be moved from one location to 
another either with or without the cabinet apparatus 10 attached. The 
preferable cooling capacity used in the cooling unit 180 is sufficient to 
chill the cabinet 10 to a temperature range of between about 33 degrees F. 
to about 40 degrees F. with a temperature stability of .+-.2.0 degrees F. 
In order to achieve the preferred temperature range, the cooling unit 180 
is preferably equipped with a 1 horsepower compressor 210 having 1600 
watts of cooling capacity and is equipped with a circulating pump 224 
having a circulation rate of 4 gpm (gallons per minute) at 60 PSI 
(pressure). It is appreciated however, that the dimensions and cooling 
capacities of the cooling unit 180 may vary depending on such factors as 
insulation, rate of heat loss, etc., and are not limited to those 
described in the disclosed embodiment. The cooling unit 180 is highly 
adaptable to several desired configurations and can accommodate 
differences in operating components, without compromising the performance 
of the cooling unit 180 or deviating from the conduction cooling 
technology. 
Specifically, the input pipe unit 158 and output pipe unit 156 are 
connected to openings in a first side wall 184 of the cooling unit 180 so 
that they can transport and recirculate the fluid transfer media into and 
out of the cooling unit 180 and cabinet 10 through the attachment unit 
140. As shown in FIG. 18, the input pipe unit 158 is connected to an upper 
bypass valve 186 located in the interior of housing 182. The output pipe 
unit 156 is connected to a lower bypass valve 188 also located in the 
interior of housing 182. The lower bypass valve 188 is adjustable so that 
the rate of flow of the fluid transfer media can be controlled. A first 
recirculating connective tube 190 is attached at one end to an upper 
bypass valve first connector portion 192. The first recirculating 
connective tube 190 curves downwardly and back around to connect at its 
other end to a lower bypass valve first connector portion 194. One end of 
a second recirculating connective tube 196 is attached to an upper bypass 
valve second connector portion 198 and the other end is attached to an 
insulated heat exchanger/evaporator 200. 
As can be seen in FIG. 16, the insulated heat exchanger 200 has a 
cylindrical filling structure 202 attached to the top of the heat 
exchanger 200 and located at the first end 202 of the heat exchanger 200 
near the second recirculating connective tube 196. The filling structure 
204 has a filler cap 206 which can be removed so that chilling fluid 
transfer media can be poured into the heat exchanger 200. The preferred 
chilling fluid includes a solution of 50 percent water and 50 percent 
propylene glycol (DOWFROST.RTM. HD, Dow Chemical, USA). The heat 
exchanger/evaporator 200 converts the low pressure fluid transfer media 
into a low pressure vapor. As the fluid evaporates, latent heat is drawn 
from within the surroundings of the evaporator, and the temperature in the 
evaporator 200 decreases. This latent heat must be supplied in order to 
provide the necessary energy for the conversion of the liquid transfer 
media to a vapor or gas. 
As can be seen in FIG. 17, the heat exchanger/evaporator 200 has an 
insulated evaporator tube 208 attached to the first end 202 of the 
evaporator 200 for transporting and circulating the cooled vapor transfer 
media into a compressor 210. The compressor 210 draws away the vapor, 
compresses it, and raises the pressure and temperature of the vapor 
transfer media. A low pressure side of the compressor 210 is connected to 
the evaporator 200 via the insulated evaporator tube 208, and a high 
pressure side of the compressor is connected to a condenser 212. The high 
pressure vapor transfer media from the compressor 210 is relatively hot, 
and is transferred to the condenser 212 where it is condensed by 
maintaining the high pressure and reducing the temperature. The 
temperature reduction is achieved by cooling the condenser 212 with a 
motorized fan 214 that forces air through the condenser 212. Temperature 
reduction can also be achieved by a water-cooled condenser. In smaller 
refrigeration units, the heat may simply be dissipated to the atmosphere 
by cooling fin means. As a result of the combination of increased pressure 
and loss of heat, the vapor transfer media condenses back into a liquid 
and releases the latent heat absorbed in the evaporator 200. The liquid 
transfer media circulates through other components Of the cooling unit 180 
and when it is sufficiently cooled, it is transported from the cooling 
unit 180 to the cabinet 10 through the attachment unit 150. 
As can be seen in FIGS. 17 and 18, at the second end 216 of the heat 
exchanger/evaporator 200 is attached a third recirculating connective tube 
218 which recirculates the transfer media and connects to an upper end of 
an inline filter 220. The other upper end of the inline filter 220 is 
connected to a first attachment portion 222 of a cooling unit circulating 
pump 224. The inline filter 220 acts to filter out any sediments from the 
fluid transfer media after it returns from the shelves 12 of cabinet 10 
for recycling in the cooling unit 180. A second attachment portion 226 of 
the cooling unit circulating pump 224 connects directly to a cooling unit 
circulating pump motor 228. The motor 228 provides the energy or work 
input to the compressor 210. Finally, a third attachment portion 230 of 
the cooling unit circulating pump 224 connects to one end of a fourth 
recirculating connective tube 232. The opposite end of the fourth 
recirculating connective tube 220 is connected to a lower bypass valve 
second connector portion 234. After the transfer media has circulated 
through the components of the cooling unit 180 and been transformed from a 
liquid to a vapor and back to a liquid, the sufficiently chilled fluid 
transfer media is transported through the lower bypass valve 188 and into 
the output pipe unit 156 for flow into the shelves 12 of the cabinet 10 
through attachment unit 150. 
As shown in FIGS. 17 and 18, attached to a second side wall 236 of cooling 
unit 180 and positioned above the second end 216 of the evaporator 200 is 
a pressure sensing unit 238 having a pressure gauge 240. The pressure 
sensing unit 238 is connected to a copper wire 242 which forms a loop at 
its mid-section and then straightens to connect to the top of the cooling 
unit circulating pump 224. The pressure generated by the circulating pump 
224 is registered on the pressure gauge 240 via the copper wire 242. 
Located to the side of the pressure sensing unit 238 and also attached 
directly to the second side wall 236 is a control box 244 which houses 
various electronic components for operating the cooling unit 180 of the 
cooling assembly 140. 
FIG. 19 is an alternate embodiment of the refrigeration/cooling unit 180 
used with an alternate embodiment of the cabinet 10 of the present 
invention. In this embodiment a refrigeration/cooling unit 300 similar to 
the cooling unit shown in FIG. 16, but having no wheels, is positioned on 
the roof of a conventional walk-in refrigerator 302. For example, when 
food items that need to be refrigerated are delivered by truck to a store 
or restaurant, it is desirable to wheel a multi-shelf cart directly to the 
truck, stack the food items on the cart, and wheel the cart into a walk-in 
refrigerator. Generally, the food items on the cart are cooled by 
convection refrigeration in a conventional walk-in refrigerator. However, 
when the cooling unit 300 of the present invention is used in conjunction 
with the walk-in refrigerator 302 and a cart apparatus 304, the 
refrigerator 302 is activated by the cooling unit 300 and conduction 
cooling is achieved. Thus, the food items are cooled at a faster rate with 
the use of the attached cooling unit 300. The output pipe unit 156 and the 
input pipe unit 158 of the cooling unit 300 are extended through the roof 
of the refrigerator 302, and the output pipe unit 156 is connected to a 
first quick-connector 306 and the input pipe unit 158 is connected to a 
second quick-connector 308. The quick-connectors 306, 308 are directly 
connected to the back manifold of the cart apparatus 304, and they are 
similar to the quick-connectors shown in FIGS. 11-13. In an alternative 
embodiment, the quick-connectors may be connected to a single large 
manifold (not shown) having multiple outlets for connection to many carts. 
The quick-connectors 306, 308 act to generate the flow of chilling fluid 
to shelves 310. Unlike the cabinet apparatus 10 of FIG. 1, the cart 
apparatus 304 used in conjunction with the cooling unit 300 disclosed in 
this embodiment has no side panels, no back panel and no front doors. The 
cart 304 is equipped with heating/cooling exchange shelves 310, but the 
shelves 310 are supported only by four corner posts 312 and have no 
housing around them. The cooling unit 300 is typically used with a large 
walk-in refrigerator 302 that is capable of holding ten or more carts 304 
at a given time. Each cart 304 may be equipped with quick-connectors 306, 
308 for connection to the cooling unit 300. In an alternative embodiment, 
a single large manifold (not shown) having multiple quick-connector 
outlets may be positioned on the roof of the refrigerator or within the 
refrigerator for connection to the carts inside the refrigerator. A large 
heating unit 314 may also be positioned on the roof of the walk-in 
refrigerator 302 and may be connected to cart 304. Thus, the cart 304 has 
the capability of heating or cooling food articles depending on whether 
the heating unit 314 or the cooling unit 300 is connected to the cart. 
However, the heating unit 314 and cooling unit 300 cannot be connected to 
the cart or carts simultaneously. Typically, the heating unit 314 of this 
embodiment is larger in size and capacity than the heating element 30 of 
FIG. 2. For example, if each cart 304 requires 3 gallons of water to heat 
it and 20-30 carts are housed within the refrigerator, the heating unit 
314 requires a reservoir large enough to hold 60-90 gallons of water. 
While the specific embodiments have been illustrated and described, 
numerous modifications come to mind without markedly departing from the 
spirit of the invention. The scope of protection is, thus, only intended 
to be limited by the scope of the accompanying claims, rather than by the 
description of the preferred embodiment.