U.S. patent application number 09/849509 was filed with the patent office on 2002-11-07 for apparatus and method for controlling temperature for a self-service food display.
Invention is credited to Houtman, Kenneth James, McNeal, Scott Alan, Walker, Darrel Jay.
Application Number | 20020162347 09/849509 |
Document ID | / |
Family ID | 25305901 |
Filed Date | 2002-11-07 |
United States Patent
Application |
20020162347 |
Kind Code |
A1 |
Walker, Darrel Jay ; et
al. |
November 7, 2002 |
APPARATUS AND METHOD FOR CONTROLLING TEMPERATURE FOR A SELF-SERVICE
FOOD DISPLAY
Abstract
A self-service food display in which a food tray that is
supported by a support structure is cooled by an air stream that
passes over and under the tray. The tray has opposed end sections
and one or more intermediate sections. The air stream is uniformly
distributed over the intermediate sections to substantially
maintain the same temperature in the vicinity thereof. The air
stream is distributed to the opposed end sections in higher volumes
to minimize heat transfer with ambient. The air stream also forms
an air curtain that extends above three sides of the food tray.
Additionally, the air stream is distributed at an angle to an upper
surface of the food tray in a manner that provides higher volumes
to the opposed end sections to minimize heat transfer.
Inventors: |
Walker, Darrel Jay; (Mt.
Pleasant, MI) ; Houtman, Kenneth James; (Mt.
Pleasant, MI) ; McNeal, Scott Alan; (Shepherd,
MI) |
Correspondence
Address: |
Paul D. Greeley, Esq.
Ohlandt, Greeley, Ruggiero & Perle, L.L.P.
One Landmark Square, 9th Floor
Stamford
CT
06901-2682
US
|
Family ID: |
25305901 |
Appl. No.: |
09/849509 |
Filed: |
May 4, 2001 |
Current U.S.
Class: |
62/256 ; 62/407;
62/458 |
Current CPC
Class: |
A47F 3/0447 20130101;
A47F 10/06 20130101; A47F 2010/065 20130101 |
Class at
Publication: |
62/256 ; 62/458;
62/407 |
International
Class: |
A47F 003/04; F25D
017/04; F25D 013/00 |
Claims
What is claimed is:
1. A self-service food display comprising: a support structure
having a base, a back and a top; a food tray having a front end, a
back end and opposed side ends and supported by said support
structure so as to be exposed to ambient on said front and said
opposed side ends; a ductwork extending beneath said food tray, up
said back and across said top and having air curtain ports arranged
therein for the formation of a front air curtain and at least one
side air curtain; and means for circulating a cool air stream
through said ductwork and to form said front air curtain and said
at least one side air curtains.
2. The self-service food display of claim 1, wherein at least a
first one of said air curtain ports is disposed along a front of
said top, at least a second one of said air curtain ports is
disposed along at least one side of said top, and wherein at least
a third one of said air curtain ports is disposed along said front
end and along at least one of said opposed side ends of said
tray.
3. The self-service food display of claim 1, wherein said ductwork
is in fluid communication with a passageway directly under said
tray so as to provide a first airflow path for said circulating
cool air stream to cool the underside of said tray.
4. The self service food display of claim 3, further comprising a
plurality of ports disposed in fluid communication with said
ductwork in a location to provide a second airflow path
substantially parallel to and across an upper surface of said
tray.
5. The self service food display of claim 1, further comprising a
plurality of ports disposed in fluid communication with said
ductwork in a location to provide a second airflow path
substantially parallel to and across an upper surface of said
tray.
6. The self-service food display of claim 1, further comprising an
array of ports disposed at a location in said ductwork to provide a
uniform distribution of air flow in a third path that is incident
to an upper surface of said food tray at an acute angle.
7. The self-service food display of claim 5, further comprising an
array of ports disposed at a location in said ductwork to provide a
uniform distribution of air flow in a third path that is incident
to an upper surface of said food tray at an acute angle and to
provide a uniform temperature throughout said third path in the
vicinity of said tray.
8. The self-service food display of claim 3, further comprising an
array of ports disposed at a location in said ductwork to provide a
uniform distribution of air flow in a third path that is incident
to an upper surface of said food tray at an acute angle and to
provide a uniform temperature throughout said third path in the
vicinity of said tray.
9. The self-service food display of claim 3, wherein said tray has
two opposed side sections and one or more intermediate sections,
and wherein said fluid communication establishes a first volume of
said cool air stream that is uniformly distributed under said
intermediate sections and a pair of second larger volumes of said
cool air stream that are distributed under said opposed sections to
minimize heat transfer with ambient.
10. The self-service food display of claim 5, wherein said tray has
two opposed side sections and one or more intermediate sections,
and wherein said fluid communication establishes a first volume of
said cool air stream that is uniformly distributed over said
intermediate sections and a pair of second larger volumes of said
cool air stream that are distributed over said opposed sections to
minimize heat transfer with ambient.
11. The self-service food display of claim 6, wherein said tray has
two opposed side sections and one or more intermediate sections,
and wherein said array of ports is arranged to establish a first
volume of said cool air stream that is uniformly distributed to
said intermediate sections and a pair of second larger volumes of
said cool air stream that are distributed to said opposed sections
to minimize heat transfer with ambient.
12. A self-service food display comprising: a support structure; a
food tray that is supported by said support structure and that has
a pair of opposed side sections and one or more intermediate
sections; a ductwork that is positioned with respect to said food
tray to provide a cooling air stream over and under said food tray,
wherein said ductwork includes a plurality of ports arranged to
distribute first volumes of said cooling air stream over and under
said intermediate sections to maintain a substantially uniform
temperature thereof and to distribute second volumes of said
cooling air stream over and under said opposed end sections, and
wherein each of said second volumes is larger than any of said
first volumes to minimize heat transfer to ambient; and means for
circulating said cool air stream through said ductwork.
13. The self-service food display of claim 12, wherein said first
and second volumes of the cooling air stream flow substantially
parallel to said food tray, and wherein said plurality of ports is
further positioned to distribute third volumes and fourth volumes
of said cooling air stream at an angle to an upper surface of said
intermediate and opposed end sections, respectively.
14. The self-service food display of claim 13, wherein each of said
fourth volumes is larger than any of said third volumes so as to
minimize heat transfer to ambient.
15. The self-service food display of claim 12, wherein said
plurality of ports is further positioned to distribute said cooling
air stream in the form of air curtains extending above three sides
of said food tray.
16. A method of cooling a food tray of a self-service food display,
wherein said food tray has a pair of opposed end sections and one
or more intermediate sections, said method comprising: (a)
providing a cooling air stream; (b) flowing said cooling air stream
over and under said intermediate sections in a manner to provide a
substantially uniform temperature in the vicinity of said food
tray; and (c) flowing said cooling air stream over and under said
opposed end sections in a manner to minimize heat transfer to
ambient.
17. The method of claim 16, further comprising: (d) flowing said
cooling air stream in a manner to provide an air curtain that
extends above three sides of said food tray.
18. The method of claim 16, further comprising: (e) flowing said
cooling air stream in a manner to provide an air flow at an acute
angle to an upper surface of said food tray in a manner that
provides a uniform volumes of said cooling air stream to said
intermediate sections and that provides higher volumes of said
cooling air stream to said opposed end sections to minimize heat
transfer to ambient.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a self-service food display for
the presentation of food items, for example, a salad bar.
BACKGROUND OF THE INVENTION
[0002] Self-service food displays that present food items to diners
need to maintain the food items at an appropriate serving
temperature. Thus, the self-service display needs to maintain a
cool environment for the case of salad items or other items that
need refrigeration. One type of prior art self-service food display
provides a cool environment by disposing the food items in
containers on a layer of ice. This has the disadvantages of too
much cooling, i.e., freezing, and of disposal of melted water.
[0003] Another type of refrigerated display counter is shown in
U.S. Pat. No. 4,592,209. This display counter has a tray upon which
the food is displayed. A cooling air stream is circulated over the
food in a direction generally parallel to the tray via a ductwork
that extends along the front, under and back sides of the tray. A
glass window is provided at the customer or front side of the
display case. This display counter has the disadvantage that the
diner must lift the glass window to pick up a food item. Also, the
display counter is subject to non-uniform temperatures across the
length of the salad bar due to heat transfer leakage
[0004] Refrigerated food display cases for food shopping
applications typically have a tank in which the food is disposed. A
food shopper must reach down into the tank to get a food item. A
cooled air stream is circulated over the top of the tank and
through a ductwork that extends along the front, under and back
sides of the tank. A blower mechanism and a refrigerated evaporator
are usually disposed in the ductwork. Refrigerated food display
cases of this type are disclosed in U.S. Pat. Nos. 2,967,404,
3,543,532, 4,106,305, 4,295,340 and 4,329,852.
[0005] Thus, there is a need for a self-service display that
maintains a uniform temperature for the displayed food items.
[0006] There is also a need for a method of maintaining a uniform
temperature for the displayed food items
SUMMARY OF THE INVENTION
[0007] A self-service food display according to the present
invention includes food tray that is supported by a support
structure. A ductwork is positioned with respect to the food tray
to provide a cooling air stream over and under the food tray. The
ductwork includes a plurality of ports arranged to distribute first
volumes of the cooling air stream over and under one or more
intermediate sections of the food tray to maintain a substantially
uniform temperature thereof. The arrangement of ports is also such
as to distribute second volumes of the cooling air stream over and
under opposed end sections of the food tray. Each of the second
volumes is larger than any of the first volumes so as to minimize
heat transfer to ambient.
[0008] According to another aspect of the self-service food display
of the invention, the first and second volumes of the cooling air
stream flow are substantially parallel to the food tray. The ports
are further positioned to distribute third volumes and fourth
volumes of the cooling air stream at an angle to an upper surface
of the intermediate and opposed end sections. Each of said fourth
volumes is larger than any of said third volumes so as to minimize
heat transfer to ambient.
[0009] According to another aspect of the self-service food display
of the invention, the plurality of ports is further positioned to
distribute the cooling air stream in the form of air curtains
extending above three sides of the food tray.
[0010] An alternate embodiment of the self-service food display of
the present invention includes a support structure having a base, a
back and a top. A food tray having a front end, a back end and
opposed side ends is supported by the support structure so as to be
exposed to ambient on the front end and the opposed side ends. A
ductwork extends beneath the food tray, up the back and across the
top of the support structure. A plurality of air curtain ports is
arranged in the ductwork for the formation of a front air curtain
and one or more opposed side air curtains. At least one of the air
curtain ports is disposed along a front of the top. At least a
second one of the air curtain ports is disposed along one of
opposed sides of the top. At least a third one of the air curtain
ports is disposed along the front end and the opposed side ends of
the tray.
[0011] According to another aspect of the alternate embodiment, the
ductwork is in fluid communication with a passageway directly under
the tray so as to provide a first airflow path for the cool air
stream to cool the underside of the tray. According to still
another aspect of the alternate embodiment, a plurality of ports is
disposed in fluid communication with the ductwork in a location to
provide a second airflow path substantially parallel to and across
an upper surface of the tray.
[0012] According to a further aspect of the alternate embodiment,
an array of ports is disposed at a location in the ductwork to
provide a uniform distribution of air flow in a third path that is
incident to an upper surface of the food tray at an acute angle to
provide a uniform temperature throughout the third path in the
vicinity of the tray.
[0013] According to a still further aspect of the alternate
embodiment, the food tray has two opposed side sections and one or
more intermediate sections. A first volume of the cool air stream
is uniformly distributed under the intermediate sections and larger
volumes of the cool air stream are distributed under any of the
opposed sections that are exposed to ambient to minimize heat
transfer.
[0014] The method of the present invention cools a food tray of a
self-service food display. The food tray has a pair of opposed end
sections and one or more intermediate sections. The method provides
a cooling air stream. The cooling air stream is flowed over and
under the intermediate sections in a manner to provide a
substantially uniform temperature in the vicinity of the food tray.
The cooling air stream is also flowed over and under the opposed
end sections in a manner to minimize heat transfer to ambient.
[0015] According to an aspect of the method of the invention, also
flows the cooling air stream in a manner to provide an air curtain
that extends above three sides of the food tray. According to
another aspect of the method, the cooling air stream is also flowed
at an acute angle to an upper surface of the food tray in a manner
that provides uniform volumes of the cooling air stream to the
intermediate sections. This flow also provides higher volumes of
the cooling air stream to the opposed end sections to minimize heat
transfer to ambient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other and further objects, advantages and features of the
present invention will be understood by reference to the following
specification in conjunction with the accompanying drawings, in
which like reference characters denote like elements of structure
and:
[0017] FIG. 1 is a front view of the self-service display of the
present invention;
[0018] FIG. 2 is a top view of FIG. 1;
[0019] FIG. 3 is an enlarged view taken along line 3-3 of FIG.
1;
[0020] FIG. 4 is a view taken along line 4-4 of FIG. 3;
[0021] FIG. 5 is a perspective view of the food tray assembly of
the self-service display of FIG. 1;
[0022] FIG. 5A is a view taken along line 5A-5A of FIG. 3;
[0023] FIG. 6 is a perspective view of the blower assembly of the
self-service food display of FIG. 1;
[0024] FIG. 7 is a plan view of an overhead air passageway of the
self-service food display of FIG. 1; and
[0025] FIGS. 8-10 are perspective views of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Referring to FIGS. 1 and 2, a self-service food display 20
includes a pair of display stands 22 and 24 that are integrally
connected with one another. It will be apparent to those skilled in
the art that only one stand 22 or 24 may be used or that more than
two stands may be used, depending on the needs of the food
purveying establishment. A side counter 26 extends outwardly from
stand 22. A similar side counter (not shown) may be provided for
display stand 24 or the left most display stand in self-service
display 20. Self-service display 20 also includes a top panel 28
that extends along its length. Top panel 28 may be a single panel
as shown or may comprised separate top panels for each display
stand 22 or 24.
[0027] Display stand 22 includes a base 30 and a back 32, which
extends upwardly from base 30. A mirror 34 is disposed on back 30
and a transparent shield 36 is disposed in hinged relationship to
top 28. Shield 36 may be clear glass or plastic. Display stand 24
includes a base 40 and a back 42, which extends upwardly from base
40. A mirror 44 is disposed on back 40 and a transparent shield 46
is disposed in hinged relationship to top 28.
[0028] A plurality of lights 50 is disposed just below top panel 28
to provide lighting for the self-service display 20. A plurality of
legs 52 are attached to bases 30 and 40 and side counter 26.
[0029] Referring to FIGS. 3 and 4, display stand 30 further
includes a box frame 60. Box frame 60 has a front side 62, a right
side 64, a left side 66 and a bottom 68. Right and left sides 64
and 66 and bottom 68 are attached to back 32 by any suitable means,
such as brackets (not shown). A box 70 has a bottom 72 and a front
74 formed of an integral L-shaped member, but could be separate
pieces that are joined together. Box 70 is positioned in the upper
part of base 30 and supported to box frame 60 by one or more
brackets 76 and to back 32 by any suitable means, such as brackets
(not shown).
[0030] A plurality of food items 78 are located on a food tray
assembly 80, which is disposed above box 70. Food tray assembly 80
is dimensioned and positioned to form a gap 82 with front side 62,
right side 64 and left side 66 of box frame 60. Food tray assembly
80 has a front panel 84 that rests on a top 71 of box 70. A bracket
86 also supports food tray assembly 80. Bracket 86 extends upwardly
from bottom 72 of box 70. Bracket 86 has a first end 88 attached to
bottom 72 and a second end 90 attached to a bottom surface of food
tray assembly 80.
[0031] Self-service food display 20 includes passageways 92, 94 and
96 that form ductwork for circulating an air stream to maintain
food items 78 cooled. Box 70, back 32 and the bottom of food tray
assembly 80 form passageway 92. A plurality of fans 132 and an
evaporator coil 99 are disposed in passageway 92. Evaporator coil
99 is cooled by a refrigerant that is circulated therethrough by
means not shown. Passageway 94 is formed by back 32 and the back of
mirror 34, which is held in spaced relation to back 32 by a
plurality of spacers 95. Passageway 96 is mounted to top 28 and/or
back 32. Fans 132 operate to circulate an air stream in a path that
includes passageways 92, 94 and 96 as shown by arrows 97. The
circulating air stream is cooled by evaporator coil 99.
[0032] Referring to FIGS. 3 and 5, food tray assembly 80 includes a
top 100, a bottom 114, front panel 84, a back splash 102, a side
110 and a back 138 (FIG. 6). Food tray assembly 80 is apportioned
into separate cooling plate sections 102A-102E. Cooling plate
section 102A includes a back splash 104A, a top 106A, a front 84A
and a bottom 112A. Cooling plate sections 102B-102D are
substantially the same. For example, cooling plate section 102C has
a back splash 104C, a top 106C, a front 84C and a bottom 112C. A
plurality of partitions 115, 116, 118, 120, 122 and 123 extend
upwardly from bottom 114 to form a separate under tray air duct in
each cooling plate section 102A-102E. Fronts 84A-84E each include
apertures for the passage of cooling air. For example, fronts 84A
and 84C have apertures 124A and 124C, respectively. Side 110 of
cooling plate section 102A includes an aperture 126 for the passage
of air.
[0033] Partitions 115, 116, 118, 120, 122 and 123 are attached to
the underside of tray 100 by any suitable means, such as spot
welding. As shown in FIG. 3, bottom 114 is positioned so that there
is a front separation 107 between bottom 114 and front panel 84 and
a back separation 109 between bottom 114 and back 32. Front
separator 107 allows airflow through apertures 124A-124E and 126 to
passageway 92.
[0034] Referring to FIGS. 3, 5 and 5A, end partition 115 is
positioned a short distance from side 110 to allow airflow through
aperture 126 into passageway 92.
[0035] Back splashes 104A-104E have disposed therein a plurality of
apertures 128A-128E, respectively. Apertures 128a-128E are in fluid
communication with the circulating air stream to divert a portion
thereof in an airflow across the top of food tray assembly 80 to
gap 82 where it enters passageway 92. Aperture 128A in end cooling
plate 102A is larger than the apertures in the cooling sections
intermediate the opposite end of self-service food display 20. This
assures a greater or larger volume of cool airflow at the ends of
self-service food display 20 to minimize heat transfer from
ambient. The airflow across the top of food tray assembly 80 is
shown in FIG. 8 as leaving passageway 94 via apertures 128A-128E,
flowing across cooling plates 102A-102E, entering passageway 92 via
front apertures 124A-124E to passageway 94. The higher volume
airflow across end cooling plate 102A is depicted by the more
concentrated arrows 170.
[0036] Referring to FIGS. 3 and 6, a blower assembly 130 includes
bracket 86 to which fans 132 are mounted. Bracket 86 includes a
plurality of apertures 134. Fans 132 are mounted on one side of the
bracket 86 in registry with apertures 134. A plurality of filter
covers are mounted in registry with apertures 134. Bracket 138
includes a vertical portion 138 that forms a back of food tray
assembly 80 between bottom assembly 114 and top assembly 100. A
plurality of apertures 140A-140E are disposed in vertical portion
138.
[0037] Referring to FIGS. 3, 5 and 6, a plurality of under tray
ducts are provided for cooling plates 102A-102E by bottom 114 and
vertical portion 138. For example, cooling plate 102A has an under
tray duct 142A formed by bottom 114, partitions 115 and 116 and
vertical portion 138. Under tray duct 142A is in fluid
communication with the circulating air stream via front separation
107, back separation 109 and apertures 140A. Apertures 140A are
greater in number than the apertures of the cooling plates
intermediate the two ends of self-service food display 20. For
example, cooling plate 102A has two apertures 140B vis-a-vis five
apertures 140A for cooling plate 102A. This distribution of
apertures allows extra cooling by the circulating air stream to
compensate for heat loss at the ends of self-service food display
20. The airflow through the under tray ducts is shown in FIG. 9 by
the dashed arrows in a path that includes apertures 140A-140E,
front separation 107, back separation 109 and passageway 92. The
more concentrated arrows 177 depict the higher volume airflow in
duct 142A.
[0038] Referring to FIG. 3, shield 32 is mounted to top panel 28
and/or to passageway 96. A pivot 152 is mounted to allow shield 36
to rotate upward from the position shown to allow easy access to
place food on food tray assembly 80 or to clean self-service food
display 20. Passageway 96 includes an elongated air nozzle 154 that
includes an array of tubes 156 arranged to form the circulating air
stream into a plurality of air jets that collectively form an air
curtain between nozzle 154 and apertures 124A-124E to passageways
92, 94 and 96 as shown in FIG. 9.
[0039] Referring to FIGS. 3 and 7, passageway 96 includes a bottom
158 in which an array of intermediate apertures 160 is disposed
between a pair of end apertures 161. A plurality of baffles 162
guide air to end apertures 161 and intermediate apertures 160. End
apertures 161 are larger than intermediate apertures 160 so as to
provide a larger volume of air along the ends of self-service food
display 20 so as to form a side air curtain to minimize heat
transfer from ambient. Airflow in the side air curtain is drawn
into passageway 92 via aperture 126 (FIG. 5). This side curtain
airflow is shown in FIG. 10 by the side arrows 176 that flow
downwardly from passageway 96.
[0040] Passageway 96 is in fluid communication with the circulating
air stream via apertures 159 located in a rear wall 166 thereof.
Thus, a portion of the circulating air stream is diverted into
passageway 96 and distributed via apertures 159 and 60 in an
airflow that is directed downwardly on food items 78, as shown by
dotted arrows 164 at an acute angle to tray 100. This airflow
merges with the airflow that flows from apertures 128A-128E to
apertures 124A-124E.
[0041] It will be apparent to those skilled in the art that the
side air curtains and/or larger air volumes over and under tray 100
can be omitted for any end section that is not exposed to
ambient.
[0042] The present invention having been thus described with
particular reference to the preferred forms thereof, it will be
obvious that various changes and modifications may be made therein
without departing from the spirit and scope of the present
invention as defined in the appended claims.
* * * * *