TECHNICAL FIELD AND BACKGROUND ART
[0001] This invention relates to a packaging tray and is particularly concerned with such
trays as are used for the transportation and storage of load bearing packages (such
as cartons of milk, soft drink or the like) whereby several similar trays loaded with
the packages can be stacked as a vertical column with the trays in spaced relationship
so that each upper tray is mounted and supported on the packages carried by the immediately
underlying tray. Trays of the kind described are commonly employed for carrying so-called
"gable-top" containers or packages and it has hitherto been proposed, for example
in G.B. Patent Specification No. 2,079,256B, for such trays to have a base part with
a substantially flat upper surface on which the packages are to stand and an under
surface which is profiled to provide substantially parallel channels with a cross
section corresponding to the shape of the tops of the packages which are to be carried.
The profiled under surface of the tray is intended to permit the tray to be located
on and supported by the tops of packages carried by a similar underlying tray and,
in the case of gable-top containers, with the apical form of the respective package
tops being received in the respective channels. It is an object of the present invention
to provide a packaging tray of the kind discussed above and by which a vertical stack
of several similar trays loaded with packages can be formed with a stable configuration.
STATEMENT OF INVENTION AND ADVANTAGES
[0002] According to the present invention there is provided a packaging tray having a base
part with a substantially flat upper surface on which packages are to stand and an
underside surface which is profiled to form substantially parallel channels having
a cross section substantially corresponding to the shape of the tops of the packages
which are intended to be carried on the upper surface; first wall parts extending
upwardly from the periphery of the base part for retaining packages on the upper surface
thereof and second wall parts extending downwardly from the periphery of the base
part at least partially to overlie open ends of the channel adjacent thereto for restraining
packages received in those channels from sliding through the channels in a stacked
configuration.
[0003] By the tray of the present invention it is envisaged that packages such as the aforementioned
gable-top containers will be located on the upper surface of the base part with the
packages similarly orientated in substantially parallel rows and so that these packages
are restrained from sliding off the upper surface by the upwardly extending first
wall parts. With the packages loaded on a first tray, a second similar tray can be
mounted on the tops of the packages of the first tray with those tops received in
the channels which are preferably of substantially complementary shape to the tops;
in this stacking configuration the two trays will be vertically spaced so that the
upper tray is borne by the load bearing facility provided by the packages on the lower
tray. The second wall parts extend downwardly from the periphery of the upper tray
and overlie the open ends of the channels adjacent thereto, preferably to an extent
less than the full depth of those channels, so that the tops of the packages are restrained
by the second wall parts from sliding along the channels and thereby a stable vertical
stack of similarly loaded trays can be formed.
[0004] Preferably the second wall parts are formed as extensions of the first wall parts.
It is also preferred that the lower peripheral edge of the second wall parts directly
underlie at least part of the upper peripheral edge of the first wall parts so that
several similar trays when empty can be stacked vertically by the lower edges of the
second wall parts standing on the upper edges of the first wall parts. In this latter
arrangement and where the second wall parts have a height less than the depth of the
channels, the under surface of the base part at the ends of the channels adjacent
to the second wall parts can be tapered to be received smoothly and closely within
the confines of the first wall parts of the immediately underlying tray and these
tapered edges may abut the inner faces of the first wall parts of the immediately
underlying tray to stabilise the stack of empty trays. Alternatively, or in addition,
the second wall parts may have associated therewith locating flanges or webs which
are intended to co-operate with the first wall parts of a similar underlying tray
to provide stability between the empty trays in forming a vertical stack. By interconnecting
these locating flanges or webs between the second wall parts and the under surface
of the tray it is possible to improve the rigidity and load bearing characteristics
of the second wall parts.
[0005] The base part will usually be of a rectangular configuration with the channels extending
parallel to a first pair of parallel edges of the base part so that the packages are
intended to be loaded on to the upper surface in rows parallel to the first pair of
edges. Preferably the first wall parts extend upwardly from the four edges of the
base part; it is also preferred that the second wall parts extend downwardly solely
from the second pair of parallel edges of the base part to overlie the open ends of
the channels adjacent to those second wall parts - this latter arrangement facilitates
handling of the tray, particularly when several empty trays are stacked as previously
discussed, since the underside surface of the base part can be grasped beneath the
first wall parts which extend along the first pair of parallel side edges.
[0006] Preferably the tray is constructed as a one piece moulding in plastics material and
with the channels being formed by projections in the underside surface. These latter
projections will usually be hollow to provide cavities that open through apertures
in the upper surface of the base part and accordingly the projections may be provided
with ventilation and drainage holes.
DRAWINGS
[0007] One embodiment of a packaging tray constructed in accordance with the present invention
will now be described, by way of example only, with reference to the accompanying
illustrative drawings in which:
Figure 1 is a perspective view of two similar packaging trays stacked as a vertical
column and with packages in the underlying tray, the trays being shown partially cut
away to illustrate the engagement of the tops of the packages with the channels on
the upper tray, and
Figure 2 is a sectional view of parts of the two trays shown in Figure 1 and illustrates
the vertical stacking of those trays when empty.
DETAILED DESCRIPTION OF DRAWINGS
[0008] Each packaging tray is formed as a one piece injection moulding in plastics and has
a rectangular base 1 with a flat upper surface 2. Formed in the base 1 is a symmetrically
disposed array of apertures 3 which open to cavities 4 of hollow projections 5 that
extend downwardly on the underside surface of the base 1. The projections 5 form on
the underside of the tray an array of parallel channels 6 which correspond in shape
to the shape of the tops of packages 7 which are intended to be loaded on to the surface
2. In the present example the packages 7 are in the form of gable-top cartons as are
commonly used for milk, soft drink and the like, and accordingly the channels 6 have
a substantially apical cross section with each channel being formed from several pairs
of opposed projections 5. It will however be appreciated that the channels 6 can have
any desired cross sectional shape in accordance with the shape of the tops of the
particular packages which are to be carried on the tray. Of the two trays A and B
shown, the cartons 7 are loaded to stand on the surface 2 of the lower tray B so that
they are similarly orientated and disposed in parallel rows with the ridges of their
gable tops parallel to the channels 6. For the purpose of retaining the containers
on the surface 2, the rectangular base 1 is provided with a substantially continuous
peripheral upstanding side wall 8. This side wall 8 also provides a convenient guide
for locating the cartons in their rows parallel to a first pair of opposed side edges
9 and 10 of the base 1. The channels 6 extend parallel to the edges 9 and 10 and,
as shown in Figure 1, the tray A is stacked vertically above the tray B so that the
gable tops of the cartons 7 are received within the complementary channels 6 and the
tray A is supported through the cartons 7 in spaced relationship above the tray B.
[0009] Extending downwardly from the second pair of parallel side edges 11 and 12 of the
base 1 are opposed walls 13 and 14 respectively which are conveniently formed as extensions
of the upper walls 8. The walls 13 and 14 have a height less than that of the projections
5 and accordingly partly overlie the open ends of the channels 6 which are located
adjacent to those walls 13 and 14. The walls 13 and 14 thus serve as abutments to
restrain the cartons 7 from sliding longitudinally through the channels 6. By this
latter arrangement a stable vertical or column stack of similar trays loaded with
cartons 7 can be formed whereby the cartons on each tray are restrained from displacement
off that tray by the peripheral wall 8 and a tray which is supported on the tops of
cartons in an immediately underlying tray is restrained from displacement off those
cartons firstly by the abutment of the walls 13 and 14 with the cartons in the channels
at the respective ends of the rows and secondly by the retaining effect of the gabled
carton tops between the opposed pairs of projections 5.
[0010] To facilitate air circulation and drainage, the sides and bottom of the respective
projections 5 are provided with vent holes 15.
[0011] As previously mentioned, the walls 13 and 14 may be regarded as extensions of the
upper wall 8 and the lower edges 16 of the walls 13 and 14 are located to vertically
underlie the upper edges 17 of the wall part 8 with which they are respectively co-extensive.
By this arrangement several similar trays can be column stacked when empty and similarly
orientated in the manner shown in Figure 2 whereby each of the upper trays in the
column is supported by the lower edges 16 of its walls 13 and 14 standing on the upper
edges 17 of the walls 8 on the immediately underlying tray. It will be seen from Figure
2 that in this empty stack arrangement the projections 5 extend downwardly to be located
partly within the enclosure formed by the upper wall 8 of the immediately underlying
tray. Outer walls of the projections 5 which are located parallel and adjacent to
the edges 9 and 10 are received closely within the wall 8 of the underlying tray to
restrain relative displacement between the two trays in a direction normal to the
rows of channels 6. Extending between and interconnecting the lower walls 13 and 14
and the ends of the projections 5 which are adjacent thereto are webs or flanges 18
(see Figure 2) which reinforce the rigidity of the side walls 13 and 14. In addition,
the webs or flanges 18 are extended below the walls 13 and 14 and are tapered as shown
at 19 in Figure 2 so that they will be received closely within the enclosure formed
by the side wall 8 of the immediately underlying tray above the edges 11 and 12 of
that tray so that the abutment of the webs or flanges 18 of the upper tray with the
wall 8 of the lower tray restrains the two trays from relative displacement in a direction
parallel to the channels 6. The tapering 19 of the webs orflanges 18 provides a convenient
lead-in for stacking one tray on top of another empty tray.
[0012] It will be noted that the downwardly extending wall parts 13 and 14 are restricted
to the extent of the opposed edges 11 and 12. This permits the underside of the base
1 to be accessible beneath the opposed edges 9 and 10 and provides a convenient position
at which the tray can be grasped and lifted from a stack (especially from a stack
of empty trays). If required the projections 5 adjacent to and at the mid-part length
of the edges 9 and 10 can be rebated as indicated at 20 to provide enlarged and opposed
areas or regions on the underside of the base at which the tray can be grasped to
facilitate lifting and stacking.
1. A packaging tray having a base part with a substantially flat upper surface on
which packages are to stand and an underside surface which is profiled to form substantially
parallel channels having a cross section substantially corresponding to the shape
of the tops of the packages which are intended to be carried on the upper surface;
first wall parts extending upwardly from the periphery of the base part for retaining
packages on the upper surface thereof and second wall parts extending downwardly from
the periphery of the base part at least partially to overlie open ends of the channels
adjacent thereto for restraining packages received in those channels from sliding
through the channels in a stacked configuration.
2. A tray as claimed in claim 1 in which lower edge parts of the second wall parts
underlie upper edge parts of the first wall parts whereby two similar trays can be
vertically stacked when empty with the lower edge parts of the upper tray supported
on the upper edge parts of the lower tray.
3. A tray as claimed in either claim 1 or claim 2 in which the channels are formed
by downwardly extending projections on the underside of the base part.
4. A tray as claimed in any one of the preceding claims in which the second wall parts
have a height less than the depth of the channels.
5. A tray as claimed in claim 4 when appendant to claim 2 in which the projections
are arranged so that with said two stacked and empty trays the projections of the
upper tray are partly received closely between first wall parts of the lower tray
whereby abutment between said projections and said first wall parts restrains relative
displacement between the two trays.
6. A tray as claimed in any one of the preceding claims in which flanges or webs are
provided between and interconnect the second wall parts and the underside of the tray
for reinforcing those wall parts.
7. A tray as claimed in claim 6 when appendant to claim 3 in which the webs or flanges
interconnect between the second wall parts and the projections adjacent to those wall
parts.
8. A tray as claimed in either claim 6 or claim 7 when appendant to claim 2 in which
the flanges or webs are arranged so that with said two stacked and empty trays, the
flanges or webs of the upper tray are received closely between first wall parts of
the lower tray whereby abutment between said flanges or webs and first wall parts
restrains relative displacement between the two trays.
9. A tray as claimed in claim 8 in which the flanges or webs are tapered to provide
a lead-in between the first wall parts of the lower tray.
10. A tray as claimed in any one of the preceding claims in which the base part is
substantially rectangular and the channels extend as an array substantially parallel
to a first pair of parallel side edges of the base part.
11. A tray as claimed in claim 10 in which the first wall parts extend upwardly from
the four side edges of the base part.
12. A tray as claimed in either claim 10 or claim 11 in which the second wall parts
extend downwardly solely from the second pair of parallel side edges of the base part.
13. A tray as claimed in claim 12 when appendant to claim 3 in which the projections
adjacent to said first pair of parallel side edges of the base part are rebated to
provide opposed regions on the underside of the base part at which the tray can be
grasped beneath said side edges.
14. A tray as claimed in any one of the preceding claims and formed as a one piece
moulding in plastics.
15. A tray as claimed in claim 14 when appendant to claim 3 in which the projections
are hollow and form cavities which open through apertures into the upper surface of
the base part.
16. A tray as claimed in claim 15 in which the hollow projections are provided with
ventillation or drainage holes.