Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FOOD TRAY
BACKGROUND
[0001] Food trays for holding and heating a food product are well known.
One type in
common use has a single compartment. When a pasta or other low value product
is heated for
consumption in the single compartment, any sauce, which may contain meat and
or vegetables, is
layered on top or beside of the low value product. Heating of the food
arranged in this manner
causes the flavours to blend and textures to deteriorate. Another food tray
has two
compartments, one beside the other. Heating does not cause blending of
flavour, but having to
spoon sauce from ne compartment to another for consumption by the customer is
inconvenient.
[0002] In another food tray available in Europe from InterFrost GmbH, a
smaller paperboard
tray is nested snugly within a larger paperboard tray. The two trays fit
tightly together. Sauce
may be placed in the smaller tray, and pasta or rice in the larger tray. Upon
heating of the
InterFrost food tray, steam may build up in the lower tray, and may be
released suddenly when
the smaller tray is removed from the larger tray. In addition, due to the
close tight fit of the
smaller tray in the larger tray, the smaller tray tends to stick in the larger
tray, and pulling on the
smaller tray can result in a sudden release of the smaller tray, causing a
risk of spilling hot food
product from the smaller tray. The steam and heat generated from the lower
tray may cause the
upper tray to deconstruct, which increases the probability of spillage. Risk
of steam release and
hot food spill makes the food tray somewhat of a hazard to use.
SUMMARY
[0003] The food tray claimed here is intended to provide the advantages of
separate heating
of low and high value food products, while reducing the risk of spillage and
steam release. In
addition, the claimed food tray is convenient to use, and provides a pleasing
aspect to the user.
[0004] Therefore, there is provided a food tray comprising a lower tray
containing a first
food product and an upper tray nested stably at least partly inside the lower
tray, with the upper
tray containing a second food product. In one embodiment, an air permeable
interface is
provided between the upper tray and lower tray to allow venting of steam from
the lower tray
during cooking. In one embodiment, a cover is provided for one or both of the
upper food tray
and lower food tray. Each of the lower tray and the upper tray may be formed
of a material that
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is suitable for use in a microwave oven. Various constructions may be used to
create the air
permeable interface, such as lugs, ledges and lips. The upper tray may sit
above the lower tray,
or may have an upper edge lower than the upper edge of the lower tray. The
trays are preferably
nested loosely for ease of removal of the upper tray from the lower tray.
Various configurations
of cover may be used such as a sleeve, carton, lid or plastic film. The upper
tray may contain the
higher value food product.
[0005] In other embodiments, the top of the upper tray may be level with or
lower than the
top of the lower tray, indents may be provided in either or both the upper
tray or lower tray for
ease of removal of the upper tray, the peripheral wall of the lower tray may
be formed in upper
and lower parts, the upper part angling outward at a greater angle with
respect to a normal to the
base than the lower part; and the upper tray may have a downward facing
shoulder that rests on
an upward facing shoulder of the lower tray.
[0006] There is also provided a method of cooking food products of
different value, the
method comprising the steps of providing a food tray comprising a first food
product in a lower
tray and a second food product in an upper tray nested loosely in the lower
tray; and subjecting
the food tray to food heating energy while permitting steam to escape from the
lower tray.
[0007] These and other embodiments of the food tray are set out in the
claims, which are
incorporated here by reference.
BRIEF DESCRIPTION OF THE FIGURES
[0008] Embodiments of the food tray will now be described with reference to
the figures, in
which like reference characters denote like elements, by way of example, and
in which:
Fig. 1 is a section through a food tray comprising an upper tray and lower
tray
according to an embodiment of the invention;
Fig. 2 is a top view of the food tray of Fig. 1;
Fig. 3 shows the food tray of Fig. 1 with a cover;
Fig. 4 shows an embodiment of a food tray with a snap-on cover;
Fig. 5 is a section through a further embodiment of a food tray;
Fig. 6 is a section through a still further embodiment of a food tray;
Fig. 7 is a top view of the upper food tray shown in Fig. 6;
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Fig. 8 is a side view of a further embodiment of a food tray comprising an
upper tray
and lower tray;
Fig. 9 is a side view of the food tray of Fig. 8 at right angles to the view
of Fig. 8 with
food product in the upper and lower trays;
Fig. 10 shows the food tray of Fig. 8 with a cover;
Fig. 11 is a top view of the food tray of Fig. 8;
Fig. 12 is atop view of the lower tray of Fig. 8;
Fig. 13 is a top view of the upper tray of Fig. 8;
Fig. 14 is a section through the upper tray of Fig 8;
Fig. 15 is another section through the upper tray of Fig. 8;
Fig. 16 is a section through the lower tray of Fig 8;
Fig. 17 is another section through the lower tray of Fig. 8;
Fig. 18 is a perspective drawing of the upper tray of Fig. 8;
Fig. 19 is a perspective drawing of the lower tray of Fig. 8; and
Fig. 20 shows a section through the food tray of Fig. 8 illustrating angles of
sidewalls
of the upper tray.
DETAILED DESCRIPTION
[0009] In the claims, the word "comprising" is used in its inclusive sense
and does not
exclude other elements being present. The indefinite article "a" before a
claim feature does not
exclude more than one of the feature being present. As shown in Figs. 1 and 2,
a food tray is
formed from a lower tray 10 and an upper tray 12 nested stably at least partly
inside the lower
tray 10. An air permeable interface 14 is provided between the upper tray 12
and lower tray 10
by outwardly extending lugs 16 at the corners of the upper tray 12. The lugs
16 rest on top of the
upper edge 18 of the lower tray 10 with a gap 19 between the upper tray 12 and
lower tray 10.
The gap 19 may extend around the perimeter of the lower tray 12. With a gap
between the lower
tray 10 and upper tray 12, when product in the lower tray 10 is heated, any
steam produced can
vent through the gap 19.
[0010] The lugs 16 and gap 19 permit the upper tray 12 to sit loosely on
the lower tray 10.
The only force retarding removal of the upper tray 12 from the lower tray 10
is the force of
gravity on the upper tray 12 and its contents. Removal of the upper tray 12
from the lower tray
is therefore frictionless. The lugs 16 are at the corners of the upper tray 12
as shown, but may
be anywhere around the periphery of the upper tray 12. Four lugs are
convenient, and there
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should be a sufficient number of lugs suitably spaced around the periphery of
the upper tray 12
so that the upper tray is stable, and is resistant against tipping. To assist
stability, the lugs 16
should be near the top of the upper tray 12 so that the main mass of the upper
tray 12 and its
contents are below the lugs 16. Both the upper tray 2 and lower tray 10
include respective lips
32 and 30. The lips 32, 30 should be at least a few millimeters wide for
example 3 mm wide for
ease of sealing.
[0011] Each of the lower tray 10 and upper tray 12 may be made by injection
moulding,
thermoforming or any other suitable manufacturing process. The sidewalls 20 of
the lower tray
and the sidewalls 22 of the upper tray 12 each may have the same nesting
angle. The nesting
angle of a tray is the angle between the sidewalls and a perpendicular to the
plane defined by the
upper edge of the tray. The upper tray 12 may be made in the same mould as the
lower tray 10,
but with an insert in the mould to reduce the volume. The upper tray 12 and
the lower tray 10
may be formed of a material that is suitable for use in a microwave oven, and
also may be
formed of a material suitable for use in a conventional oven. Exemplary
materials are
polypropylene (microwave only) and dual use CPET (crystalline polyethylene
terephthalate)
available from a number of manufacturers. CPET is particularly suitable due to
its wide
temperature tolerance. The trays 10, 12 may be transparent or opaque.
[0012] As shown in Fig. 3, the food tray may be provided with a cover 24,
such as a sleeve.
The sleeve may be a paperboard sleeve into which the combined trays 10 and 12
are inserted.
The cover 24 could also be a carton that encloses both trays 10 and 12
completely.
[0013] As shown in Fig. 4, the cover may comprise a snap-on microwavable
lid 26 for the
upper tray 12. The lid 26 may extend over the lip 20 on the lower tray 10. The
cover 24 may
also include a film that is heat sealed to the lip 32 on the upper tray 12.
The film may be on the
underside of a cardboard sleeve, or a stand alone cover heat sealed to the lip
32.
[0014] As shown in Fig. 5, the air permeable interface may be formed by a
seat created by
lugs or ledges 28 formed in the sidewalls 20 of the lower tray 10 and spaced
around the
periphery of the lower tray 10, with the upper tray 12 resting directly on the
lugs or ledges 28.
The lugs or ledges 28 may be discontinuous or provided with openings to allow
the escape of
steam during cooking. As shown in Fig. 6, the air permeable interface may be
formed by the lip
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32 resting directly on the upper edge 18 of the lower tray 10. In this case,
as shown in Fig 7, the
lip 32 is preferably provided with protrusions 34 for allowing steam release.
In each of these
cases, the air permeable interface may support the upper tray 12 in the lower
tray 10 so that the
lip 32 of the upper tray 12 sits above the lower tray 10. In the example of
Fig. 7, the outwardly
extending lip 32 of the upper tray 12 sits loosely on the upper edge 18 of the
lower tray 10 to
form the air permeable interface with a gap 29 between the side walls 22 of
the upper tray 12 and
the sidewalls 20 of the lower tray 10. The upper tray 12 and lower tray 10 may
also have fluted
sides to allow venting of steam during cooking. In another embodiment, the
upper tray 12 may
sit entirely within the lower tray 10 on lugs or ledges, with a handle
provided on the upper tray
12 to allow the upper tray 12 to be easily removed from the lower tray 10.
[0015] As shown in Figs. 8-20, a further embodiment of a food tray is
formed from a lower
tray 50 and an upper tray 52. Fig. 10 shows the food tray with a cover 56. The
cover 56 may be
any suitable cover such as a heat-sealed shrinkwrap, or a plastic snap-on lid,
suitable for
microwave use. In Figs. 8-17, the lower tray 50 is shown as having side walls
perpendicular to
the base of the tray, but this is for illustrative purposes only, and its side
walls may be angled
outward as shown in Figs. 19 and 20. Likewise, the side walls of the upper
tray 52 may be
angled outward and may extend parallel to the upper side wall 66 shown in Fig.
19. Fig. 9 shows
a first food product 92 in the lower tray 50, and a second food product in the
upper tray 52.
[0016] Various air channels 46, 48 and 54 may form an air permeable
interface between the
upper tray 52 and lower tray 50. The air channels may be formed of cooperating
indentations on
the upper tray 52 and lower tray 50. The upper tray 52 has a downward facing
shoulder 70
extending around the upper tray 52, which sits on a corresponding upward
facing shoulder 68
extending around the lower tray 50. The shoulder 70 is not continuous, but is
interrupted by
parts forming the air channels 46, 48 and 54. Air channels 46 are formed from
several indents 98
in the sidewall of the upper tray 52 that extend part of the way across the
shoulder 70, the indents
98 cooperating with indents 100 formed in the sidewall of the lower tray 50.
The indents 98
form cavities that open downward, while the indents 100 form cavities that
open upward. The
cooperating indents 98 and 100 together form air channels 46.
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[0017] Air channels 48 are formed from indents 58 and 60 in the lower tray
52 and upper
tray 50 respectively. The indents 58 are formed in slanting upper sidewalls of
the lower tray 58,
and open upward. The indents 60 are sized to receive a person's finger, and
open outward from
the wall of the upper tray 52. The indents 58 and 60 cooperate to form the air
channels 48. In
addition, the indents 58 and 60, as well as the lip 62 of the upper tray 52,
allow for easy removal
of the upper tray 52 from the lower tray 50. This ease of removal is more
specifically facilitated
by the dome shape of the indent 58 on the lower tray 50, and the shape of the
indent 60 on the
upper tray 52, which are shaped to receive a person's finger.
[0018] The lower tray 50 has a side wall formed of a lower peripheral wall
64 and upper
peripheral wall 66 connected by shoulder 68, upon which the upper shoulder 70
of the upper tray
52 stably rests. The upper shoulder 70 of the upper tray 52 is attached to the
peripheral wall 72
of the upper tray 52. The lower shoulder 68 is attached to the upper
peripheral wall 66 of the
lower tray 50. Fig, 11 shows the contact area 74 between the upper shoulder 70
and the lower
shoulder 68 of the upper tray 52 and lower tray 50 respectively.
[0019] Fig. 20 illustrates the outward slant of upper and lower parts of
the side wall of the
lower tray 50. Normals 82 and 84 are drawn perpendicular to the plane 96
created by the bottom
of the lower tray 50. A projection 86 of the upper peripheral wall 66 of the
lower tray 50
intersects line 84 at an angle 78. A projection 80 of the lower peripheral
wall 64 of the lower
tray 50 intersects line 82 at an angle 76 that is smaller than angle 78.
Various angles may be
selected for the angles 76 and 78.
[0020] Each of the lower tray 50 and the upper tray 52 have upper edges
forming a flange or
lip, that is preferably at least a few millimeters wide to accommodate sealing
of the top to a
cover. The top flange or lip 88 of the lower tray 50 and the top flange or lip
90 of the upper tray
52 may be level with each other when the product is assembled, This allows
both trays to be
simultaneously sealed. This may be done with sluinkwrap or a plastic cover.
Alternatively, the
lip 90 of the upper tray may be lower than the lip 88 of the lower tray 50.
[0021] Both tray combinations 12, 10 and 52, 50 are used in the same
manner. This
description will make reference to upper tray 12 and lower tray 10, but the
same description
applies to upper tray 52 and lower tray 50. In use, food is placed in each of
the upper tray 12 and
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lower tray 10. The food product 42 in the upper tray 12 may be a higher value
food product in
terms of cost per weight than the food product 40 in the lower tray 10. Thus
the lower tray 10
may include pasta, rice or vegetable, which is usually the higher volume
product, The upper tray
12 may include a sauce, such as cheese sauce, meat or seafood sauce, or
vegetable sauce. The
food may be pre-packaged and may be pre-cooked. The food may be stored in a
frozen state
until defrosted and cooked or re-heated by the user, Water may be added to the
lower tray 10 to
assist in cooking the food product in the lower tray 10. A gap 44 may be
provided between the
top of the food product 40 and the bottom 46 of the upper food tray 12 to
avoid the food product
40 coming into contact with the bottom 46 of the upper food tray.
[0022] In one embodiment, chili may be placed in the lower tray 10 and a
biscuit in the upper
tray 12. For food product such as a biscuit that should have a crisp exterior
texture when cooked,
a susceptor board may be placed in the tray with the food product.
[0023] When sold, the food tray, including food, may be wrapped in shrink
wrap, and the
food may be frozen. For use, the customer removes the shrink wrap and deposits
the food tray in
an oven (conventional or microwave as appropriate for the materials), where
the food tray is
subject to food heating energy. If the upper tray 12 is sealed with a film, it
may be removed or
loosened prior to cooking depending on the cooking instructions. Due to the
air permeable
interface 14, the food tray permits steam to escape from the lower tray. Upon
removal of the
food tray from the oven, the higher value food product may be added to the
lower value food
product, simply by pouring the higher value food product into the lower tray.
Due to the product
being in separate trays, quicker more even heating is obtained. With the
higher value product in
the top tray, the aromas of the higher value product are easily available to
the customer upon
heating, and the higher value product also presents a pleasing aspect to the
customer. Either or
both the cover 24 or the sidewalls 20, 22 may be provided with graphics
illustrating the food
product and providing instructions for use.
[0024] Immaterial modifications may be made to the embodiments described
here without
departing from what is claimed.
