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This invention relates to food display counters of the type which are
commonly used in bakery shops and food emporia to display food
for purchase by customers. More specifically, this invention relates
to food counters of the "serve-over" type, where a shop assistant
serves a customer from behind the said counter, the rear of the
counter, being open, allowing said assistant to retrieve food
products displayed, usually on shelving or the like, within said
counter, the food being displayed to the customer on the alternate
side of the counter behind a glass, Perspex or other translucent
material shield preventing access thereto from the side of said
counter. Such counters are typically used for the storage and display
of pies, pasties, sandwiches, cream cakes and other perishable
produce which require some form of refrigeration to delay the
deterioration of the produce.
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Although the following description relates exclusively to open-backed,
serve-over counters with glass or Perspex side and front
panels used by bakers and confectioners for the display of the types
of perishable produce abovementioned, it will be immediately
apparent from an understanding of the invention that its application
need not be limited by such constraints. In particular, it is
considered by the applicant that counters according to the invention
may have application in other fields, for example for warming foods
other than those commonly sold by bakeries and other like
establishments.
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In interests of brevity, however, the following description will relate
only to serve-over counters in which refrigeration is important in
prolonging the shelf life of the displayed products.
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It is common for serve-over counters to be provided with a plurality
of shelves on which may be displayed different food products.
Refrigeration means may be provided within the counter such that
cooled air is allowed to pass over the products displayed on the
lowermost shelf within the counter. In the light of the continual
tightening of food safety regulations both within the European
Union (with which UK produce vendors must comply), and globally,
there has been an increase in the number of counters sold with
refrigeration units.
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Refrigerated serve-over counters are typically provided with a base
portion, which rests on a supporting floor of the premises in which
the counter is located, and which optionally houses the refrigerant
pump and associated electrics, glass side panels and glass front
panel above the base and at human torso height. A plurality of
shelves is provided behind the glass front panel and between the
side panels, such shelving being supported by structural members
attached to the base portion, or alternatively being supported by the
said glass side panels and front panel. In addition, a further shelf is
provided integrally with the base portion of the counter, said
further shelf being inset within the base of the counter. The relative
heights and orientations of the shelves allows a customer to view all
the displayed produce and henceforth the shelves are generally
inclined towards the front of the counter for display purposes.
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The rearward upper portion of the counter is either simply open to
allow a shop assistant to reach into the counter, or may optionally
be provided with slidably or rotatably openable door means which
when closed serve to further protect the produce displayed within
the counter from airborne contaminants and the like, and also act to
contain the refrigerated air thus enhancing the refrigerating effect
of the counter.
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There are currently two known types of refrigerated counter
available, the first of which gravitationally feeds the refrigerated air
over the produce to be chilled, and the second of which allows for
fan-assisted circulation of the refrigerated air over the said produce.
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The fan-assisted counters were devised to provide a more uniform
air temperature over the produce displayed on the lowermost shelf,
as refrigerated air falling under gravity onto produce on the
lowermost shelf of the counter was prone to uneven air movement
as it travelled over said produce. This results in less efficient
refrigeration of the produce displayed towards the front of the said
shelf, and thus the said counter.
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In both cases, only produce displayed and positioned on the
lowermost shelf within the counter is subjected to any refrigeration,
as both this shelf and the refrigeration unit are incorporated in the
base unit of the counter. The fundamental thermodynamic principle
that cool air falls, and the fact that it is impossible to mount the
refrigeration unit anywhere other than in the base portion of such
counters has hitherto prevented the refrigeration of produce stored
on any of the other shelves within the counter, unless the first
upper shelf is positioned at a low level and the solid rear of the
counter built higher to accept a particularly high baffle panel. This
particular arrangement renders it impossible to reach below the first
upper shelf into the base of the counter from the rear.
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Also, air baffling means is required to restrict the flow of air to and
over the lowermost shelf in the counters which employ fan-assisted
refrigeration techniques. Such baffles are used to reduce the flow
velocity of air over the produce displayed on the lowermost shelf, as
rapid airflow may cause drying of the produce and reduce its quality.
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In the fan-assisted refrigeration counters, the lowermost shelf is
typically provided with an air intake grill towards its front edge, a
plurality of fans being attached to the base portion of the counter
underneath the shelf approximately at its mid-way point. These fans
draw air through the air intake and blow said air at a positive
pressure underneath said shelf to an air cavity towards the rear of
the base portion of the counter in which a heat exchanger is located.
The air baffle means is provided in front of the heat exchanger
towards the rear of the lowermost shelf to restrict the flow of air,
which has passed through said heat exchanger, from the cavity onto
the lowermost shelf. The positive pressure maintained in the air
cavity by the fans and the baffle means is such that there is a
substantially uniform flow of air at a predetermined velocity
emerging from the said baffle. Air subsequently flows over the shelf
and produce displayed thereon and is drawn towards the air intake
grill at the front of the shelf. Henceforth air is circulated over the
lowermost shelf.
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It is to be noted that upright cabinet fridges and so-called "serve-into"
and "self-serve" counters of the type commonly found in
newsagents, petrol stations, supermarkets and the like do employ an
air circulation technique to refrigerate all the products on all the
shelves, but this is only possible because there is no requirement for
access to the rear of the cabinet which can thus be provided with air
baffle means over the entire height of the cabinet. Refrigerated air
can be thus urged upwardly at the rear of the cabinet through said
baffle means and allowed to pass over all the shelves provided
within said cabinet. This system is not applicable to serve-over,
open-backed counters to which the invention applies.
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It will be appreciated that there has long been a requirement in the
field of multiple-shelf display counters for refrigeration of produce
stored on shelves other than the lowermost shelf. This improvement
would automatically increase the versatility of the counter, as
perishable produce could then be stored on any shelf of the counter,
henceforth improving the display of the produce.
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It is an object of this invention to provide a counter provided with
refrigeration (or heating as indicated previously) means for the
display and refrigeration of produce on multiple shelves within said
counter, and to provide a counter refrigeration system adapted to
such purpose.
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According to the invention there is provided an open-backed, serve-over
produce display counter with a base portion with an air cavity
in which is provided heat exchange means, said counter having at
least one shelf vertically separated from the base portion supported
either by side panels or support means attached to said base
portion, said base portion also providing support for a lowermost
shelf of the counter, said base portion having air intake means
optionally provided in said lowermost shelf for intake of air, said air
from said air intake being drawn into said air cavity and contacting
with said heat exchange means which raises or lowers the
temperature of said intake air, characterised in that said counter is
further provided with air conduit means between the base portion
and said vertically separated shelf communicating with said air
cavity and having an opening above the said vertically separated
shelf, said conduit means being disposed upwardly of the base
portion and substantially or entirely behind the said vertically
separated shelf and receiving the pressurised air already subjected to
heat exchange such that said air passes over said at least one shelf.
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It is preferable that the air is drawn into said cavity by fan means,
and that the heat exchange means cools the said air, the fan means
creating an increased pressure in said air cavity to urge the air over
the heat exchange means and upwardly within said conduit means.
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It is further preferable that the air cavity also opens via a baffle
means above and toward the rear of the lowermost shelf of the
counter allowing cold air to fall onto and over said shelf for cooling
of produce thereon.
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In a most preferred aspect of the invention, the lowermost shelf is
provided with air intake means into which air is drawn by fan means
provided underneath said shelf and subsequently cooled by heat
exchange means, the orientation of the conduit means and the said
at least one shelf being such that cool air passing over said shelf
falls ultimately towards the air intake means such that air is
circulated within the counter.
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It is yet further preferable that air is caused to circulate over both
the said at least one shelf and the lowermost shelf.
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Preferably, air baffle means is employed to restrict the flow of air
over said the shelves. The baffle means also serves to increase the
pressure within the air cavity and by varying the baffle sizes, and
the fan speed it will be appreciated that any desired air flow velocity
over the said produce can be achieved.
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Preferably the air conduit means has at least one substantially
vertical portion connected to the base portion and a horizontal
portion which is disposed above and substantially or entirely behind
the said vertically separated shelf.
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Preferably the air conduit means is provided with a single or a pair
of vertical portions connected to the base portion towards
respective edges thereof.
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Thus an extremely flexible produce display counter results which is
capable of cooling (or heating) produce on more than the single
shelf which is commonly found in most existing counters.
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A specific embodiment of the invention will now be described by
way of example with reference to the accompanying diagrams,
wherein:
- Figure 1 shows schematic side elevation of a conventional fan-assisted
refrigerated display counter;
- Figure 2 shows a perspective view of the display counter of Figure
1;
- Figure 3 shows a fan-assisted refrigerated display counter adapted
according to the present invention, and
- Figure 4 shows an elevation from the rear of the counter of Figure
3.
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Referring firstly to Figure 1, there is shown a conventional produce
display counter 2 with a base portion 4 which supports a glass front
panel 6 and additional support member 8 which is rigidly attached
to said base portion 4.
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The counter 2 is provided with a first and lowermost shelf 10
capable of displaying produce, said lowermost shelf being inclined
upwardly from the front of the counter 2 for display of the produce.
In this manner a customer approaching the counter 2 from the front
can easily view all the produce displayed within the counter through
the glass front panel 6.
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There is provided a further second shelf 14 and further third shelf
16 vertically spaced from said lowermost shelf 10 which are shown
at a similar angle of inclination to said lowermost shelf.
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It is common for counters of the type shown in Figure 1 to provide
refrigeration for produce displayed on the lowermost shelf, and in
this regard said lowermost shelf 10 is provided integrally with an
air-intake grill 18 through which air may be drawn under the
assistance of a row of fans 20 provided with electrical power
through mains cables. Said row of fans 20 expel air into an air
cavity 24 underneath and behind said lowermost shelf 10. The
passage of air underneath the said lowermost shelf is bounded at the
bottom by a base portion support member 26 and at its edges by the
side walls (not shown in Figure 1 but indicated at reference numeral
28 in Figure 2). The above mentioned air passage is further
bounded on its upper side by said lowermost shelf 10, and therefore
there is practically very little air which escapes from underneath said
lowermost shelf.
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The row of fans 20 urge air into the air cavity 24.
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Within said air cavity 24, there is provided a multi-fin heat
exchanger 34 through which refrigerant is pumped via pipes 36 by a
compressor unit 38 provided with electrical power. Air flows under
fan pressure towards the rear of the cavity 24 through the heat
exchanger 34.
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After passing through said heat exchanger 34, air is urged through a
baffle 46 and subsequently flows over the produce and forward
towards the grill 18 of the lowermost shelf.
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It will be seen from the air circulation arrows included in Figure 1,
but which have not been referenced in the interests of clarity, that
an air circulation path is provided over the produce and underneath
the said lowermost shelf. The row of fans 20 expel air into the
cavity 24 at a predetermined volumetric air flow rate such that there
is a pressure differential across the baffle 46. Experimentation
with different pressure differentials, and aperture sizes within the
baffle 46, allows for a predetermined air flow velocity to be
achieved over the produce which can thus be refrigerated as desired
without any substantial drying of said produce as described above.
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The reader is also referred to Figure 2 of the specification from
which a better understanding of the air circulation underneath the
lowermost shelf 10 may be gleaned. Like reference numerals
identify like parts in both Figures 1 and 2.
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Figure 3 shows a produce display counter 50 of a similar
configuration to the counter shown in Figures 1 and 2, but which
has been adapted according to the invention. The reference
numerals used in Figures 1 and 2 have been used in Figures 3 and 4
to identify the components of the counter 50 which are identical to
those of the counter 2 for clarity.
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In particular the counter 50 is provided with an upwardly directed
conduit 52 through which air is allowed to pass in the direction
shown by arrow 54. The pressure of the air within said cavity 24 is
still above atmospheric pressure and it can escape either through the
baffle 46 and over produce displayed on the lowermost shelf or
alternatively upwardly into said conduit 52.
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The provision of the conduit 52 and the fact that the row of fans 20
pressurise the air in the cavity 24 above ambient atmospheric
pressure, allows air to be urged upwardly within the conduit 52 and
out through a baffle (not shown in Figure 3 but indicated at 56 in
figure 4) over the produce displayed on the second vertically
separated shelf 14 within the counter 50.
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It will be immediately apparent to a person skilled in the art that the
modified counter 50 provides a simple means of refrigerating
produce stored on the second shelf which has hitherto not been
possible.
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It will also be seen that two separate air circulation paths are now
set up, both of which terminate at the air intake grill 18 of the
lowermost shelf 10 due to the simple thermodynamic principle that
the cold refrigerated air will fall under gravity past the ambient air
which is of a higher temperature within the counter 50. The
selection of the sizes of both baffles 46 and 56 results in a desired
air flow velocity over both produce shelves 14, 16 while
nevertheless maintaining produce on said shelves at the desired
temperature.
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It is an advantage of the invention that existing produce display
counters could be modified and adapted according to the invention
to allow for refrigeration of produce stored on one or possibly two
or more shelves which are vertically separated from the lowermost
shelf 10, such advantage resulting from the fact that the row of fans
20 provided in conventional produce display counters generate a
pressure differential thereacross and henceforth in the cavity 24
which is sufficient to urge air upwardly within the conduit 52 and
out of one or more baffles onto the produce shelves.
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Although not specifically shown in Figure 4, it will be appreciated
instantaneously therefrom that the secondary support members 8
could additionally incorporate the said conduits 52 thus precluding
the requirement for additional structural components of the counter
50. In such circumstances, it is foreseeable that more than one
vertically separated shelf 14, the underside of which is shown in
Figure 4 at 14', may be provided, with additional connectors (not
shown) being provided in the secondary support 8 for connection
thereto of an horizontal air vent of the type shown in Figures 3 and
4 connected to the conduits 52 and indicated therein by reference
numeral 53 to allow the expulsion of air over the said second and
optionally further vertically separated shelves 14, 16.
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It is also possible that only a single conduit 52 may be provided to
support and feed air to the horizontal air vent 53. Such a
configuration would allow a cash register to be positioned at the
opposite side to that at which the single conduit 52 is provided.
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It is also to be appreciated that it is not an essential feature of the
invention that refrigerated air passes over the lowermost tray, and it
is foreseeable that the produce displayed on any shelf, to the
exclusion of or in combination with any other shelves within the
counter, may be subjected to refrigeration.
