Note: Descriptions are shown in the official language in which they were submitted.
CA 02363992 2001-11-23
DROP DOOR FOR PACKAGING CONTAINER
FIELD OF THE INVENTION
The invention relates to the structural design of an access feature (drop
door) intended to be used in a sleeve-type of packaging container. The
invention also pertains to a sleeve-type packaging container which includes
one or more such drop doors.
BACKGROUND
Sleeve-type packaging containers are generally composed of 2 plastic pallets
and a foldable sleeve (outer shell), of various designs. The vast majority of
these sleeve packs are designed to fit 2 wide and 2 or 3 high in a typical
truck trailer. Hence sleeve assembly dimensions are likely to be in the
45x48x45" dimensional bracket.
Very often, there is a need for a partial side access to the contents of the
pack, with the sleeve set-up and only the top pallet removed. This access is
usually provided by a "drop door", defined as a fold-out or pull-out section
of the sleeve.
The shape and size of a drop door may vary considerably, but could
generally be described as a rectangle with its horizontal dimension less than
half the length of the corresponding side panel and its height up to half the
useable height of the same panel. A common door size for one of the above
mentioned sleeve packs would be 20x20", for example.
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CA 02363992 2001-11-23
A pack may have 1 or 2 drop doors, typically centered left to right and
located at the upper edge of the (opposite) side panels.
Existing packaging designs feature drop doors defined by 2 vertical cuts and
one or two horizontal score-lines, as hinges. Problems: The sleeve material,
usually paper or plastic corrugated, retains most of its memory at the score
level (generally vertical flute orientation) and the drop door (or access
flap)
tends to either "spring" back toward its upright position when open, or flap
out from its vertical position when closed. Either way, misalignments are
likely to occur. Also, a hand-hole feature is usually needed for drop door
operation.
Last but not least, a container with drop doors) loses part of its stacking
strength and side-panel rigidity, due to obvious material discontinuity.
Other previous drop door designs feature a completely separate, removable
panel, that can slide in and out vertical channel guides. Problem: The
panels) are lost or their tethering becomes an impractical hazard.
The challenge became to develop a drop door that would have a clearly
defined upright (closed) position and a 180 degrees opposite (open)
position, while remaining permanently attached to the sleeve, minimizing
the stacking and side-rigidity strength reduction, and eliminating the need
for a hand hole.
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SUMMARY of the INVENTION
The proposed design solution features a slide & hinge combination access
panel (door), that operates in 2 positions: up (closed) and down (open).
BRIEF DESCRIPTION OP THE DRAWINGS
Fig. 1 is a perspective view of the drop door according to the invention;
Fig. 2 is a perspective view of a packaging sleeve on a pallet incorporating
a pair of drop doors which are shown as open or down;
Fig. 3 is a blank design for the length panel of the sleeve pack showing that
the removed section can be used to make the drop door panel;
Fig. 4 is a blank design for the width panel of the sleeve pack;
Fig. 5 is a top view of the sleeve comprising a pair of width panels (Fig. 4)
and a pair of length panels (Fig. 3);
Fig. 6 is a cross-sectional view of an exemplary door channel (H-channel)
extrusion;
Fig. 7 is a front view of the door panel having disposed therein the
pins/rods;
Fig. 7A is a front view of the door panel disposed within its vertical
channels
and showing the optional horizontal c-channel;
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Fig. 8 shows a closeup of the notched upper portion of the H-channel and
the drop door in its closed position;
Fig. 9 shows a closeup of the lower end of the H-channel with the drop door
in its open position; and
Figs. 10-13 illustrate the operation of the drop door in situ in the sleeve
pack.
DETAILED DESCRIPTION
The typical sleeve pack comprises a sleeve made of suitable material such
as corrugated cardboard or corrugated/fluted plastic (polypropylene for
example), and an upper and lower pallet. [Fig. 10]
Foor the drop door, a rectangular panel, with horizontal corrugation, is
fitted
with 2 pairs of pins: 2 upper pins and 2 lower pins. These pins are
horizontal, and may be designed as the protruding tips of 2 cylindrical rods
installed approximately 1" from the top and the bottom of the door panel,
inside the fluted material. [Figs. 1, 3 and 7]
These pins slide into 2 vertical channels, part of a custom extruded profile
resembling a modified "H" shape (cross section). [Fig. 6] The channel may
be made from any suitable material, such as polypropylene. The top portion
of the outside wing of the sliding channel is notched [Figs. 1 and 8],
allowing the upper pair of pins (rod) to disengage the channel toward the
outside of the pack, when the door is lifted about 1" from its closed
position.
[Fig. 11]
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This upward movement is prevented during transport by the top pallet. [Fig.
10]
The lower pair of pins (rod ends) remains inside the channel at all times. It
acts as a sliding mechanism for the up & down motion of the door, and as
a hinge for the outward, 180 degrees rotation of the door, once the upper
pins (rod) have cleared the channel profile (at the notch level).[Figs. 1, 2
and 9 to 13]
The assembly of the 4-pin door in the channel-fitted sleeve is achieved with
2 pairs of stop pins or rivets, that capture the lower door pins inside the
corresponding channels, while allowing sufficient vertical play for the lower
pins between the stop pins. The play enables the top door pins to slide out
of the notched upper portion of the channel to thereby the door panel to
rotate freely around the bottom rod (pins) axis. [Figs. 1, 7 and 7A]
The other 2 vertical channels, as part of the modified "H" section extrusion,
fit and are fastened with rivets over the 2 vertical edges of the door cut
(opening) in the side-panel. If desired, a third channel can be provided for
the horizontal span between the two H-channels. [Figs. 1, 7 and 7A]
The assembly offers clear and easy access to the inner volume of the pack.
It also provides stacking support through the added vertical channels, that
compensate for the missing door material in the wall of the sleeve.
The horizontal corrugation of the door panel and the natural reinforcing
provided by the pin-rods, contribute to alleviate side-deflection in the
access
door panels.
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The unique slide & hinge features described above offer the operators
maximum access to the inside and around the sleeve pack, minimizes the
risks of door "catching" of interference, while maintaining the pack's
collapsible features.
While the foregoing has described and illustrated a novel drop door system
for use with sleeve-type packing containers, it will be appreciated that the
principles and structures can be applied to the packaging of various other
products. It will also be appreciated that various modifications and
adaptations can be made without departing from the spirit of the invention
as described herein.
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