Note: Descriptions are shown in the official language in which they were submitted.
CA 02787547 2012-08-22
DOUBLE WALL STORAGE CONTAINER FOR LIQUIDS
BACKGROUND OF THE INVENTION
Various types of storage containers are well-known for containing liquids,
including agricultural chemicals. Some storage containers include double walls
which
precludes spillage or leakage of the liquid if the outer wall is damaged, such
as a puncture,
without damage to the interior wall of the container. If there is a leak in
the inner tank, the
liquid is captured by the outer tank. Some double walled containers are
fabricated as a
single unit in which the inner and outer walls cannot be separated. Other
double wail
containers include separate inner and outer tanks which nest together.
However, the
structure and manufacture of all these double wall containers is relatively
complex, and
thus costly.
Accordingly, a primary objective of the present invention is the provision of
an
improved storage container for liquids having separate inner and outer tanks.
Another objective of the present invention is the provision of an improved
storage
container for liquids which has a double walled construction.
A further objective of the present invention is the provision of an improved
storage
container for liquids having an inner tank which can be removably nested
within an outer
tank.
Still another objective of the present invention is the provision of an
improved
storage container for liquids having an inner tank which fits into an outer
tank, with the
outer tank having a centering bead to facilitate installation of the inner
tank into the outer
tank.
Yet another objective of the present invention is the provision of an improved
storage container for liquids wherein an inner tank has a top rim which
overhangs an upper
shelf or shoulder on the lower tank.
Another objective of the present invention is the provision of an improved
storage
container having separable nesting inner and outer tanks with means to
preclude rotation of
the tanks relative to one another when assembled together.
A further objective of the present invention is the provision of an improved
storage
container for liquids having dual inner and outer tanks which are molded
plastic.
I
CA 02787547 2012-08-22
Another objective of the present invention is the provision of an improved
storage
container for liquids wherein an inner tank has a bottom, a side wall and a
top molded as
one piece and an outer molded tank having a bottom, a side wall, and an upper
open mouth
for receiving the inner tank.
A further objective of the present invention is the provision of an improved
storage
container for liquids which is economical to manufacture and durable and safe
in use.
These and other objectives will become apparent from the following description
of
the invention.
SUMMARY OF THE INVENTION
The improved storage container of the present invention includes a molded
outer
tank having a bottom, a side wall and an upper open mouth, in a molded inner
tank having
a bottom, a side wall, and a top. The inner tank is separate from the outer
tank and can be
removably inserted through the open mouth of the outer tank. The outer tank
includes a
centering bead on the bottom to facilitate alignment of the inner tank within
the outer tank.
The top of the inner tank has a horizontal, downwardly facing rim which
overlies an upper
horizontal shelf or shoulder surrounding the mouth of the outer tank. A seal
may be
provided between the rim and the shelf. A capillary drip edge is provided on
the outer
perimeter of the rim of the inner tank to inhibit rain and other liquids from
migrating
between the rim and the shelf into the space between the outer tank and the
inner tank. An
indexing tab is provided on the inner tank and registers with a corresponding
notch on the
outer tank to preclude rotation of the inner tank relative to the outer tank.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of one embodiment of the improved storage
container for liquids according to the present invention.
Figure 2 is an exploded view of the container of Figure 1 showing the inner
tank
separated from the outer tank.
Figure 3 is a sectional view of the tank shown in Figure 1.
Figure 4 is a partially exploded perspective view of a second embodiment of
the
liquid storage container according to the present invention.
2
CA 02787547 2012-08-22
Figure 5 is a partial sectional view showing the inner and outer tanks of the
container shown in Figure 4 in an assembled state.
Figure 6 is a partially exploded perspective view of the container of Figure 4
showing one of the indexing tabs on the inner tank rim.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In Figures 1-3, a first embodiment of the improved storage container according
to
the present invention is designated by the reference numeral 10. The container
10 includes
and outer tank 12 and an inner tank 14, each of which is molded as a one-piece
unit. The
outer tank 12 includes a bottom wall 16 and a side wall 18. The upper end of
the side wall
18 terminates in a reduced-diameter neck 20 with an upper open mouth 22. A
horizontal
shelf or shoulder 24 extends around the perimeter of the mouth 22. A lip 26
extends
downwardly from the shelf 24 to provide additional strength and integrity for
the shelf 24.
The inner tank 14 includes a bottom wall 28, a side wall 30, and a mushroom-
type
top 32. The top 32 includes a downwardly facing horizontal rim 34. One or more
openings 35 may be provided in the top 32 for introducing and removing liquid
to and from
the interior of the tank 14. The opening 35 in the top 32 may be covered or
closed in any
convenient means, such as by a threaded cap. Lifting flanges 36 are formed in
the top 32
of the inner tank 14 and are adapted to receive hooks on chains or straps for
lifting the
inner tank 14 during installation or removal from the outer tank 12.
The bottom wall 16 of the outer tank 12 includes a centering bead 38 which
facilitates alignment of the inner tank 14 within the outer tank 12.
Preferably, the bead 38
extends 360 . In Figure 3, the bead 38 is shown to be continuous, though it is
understood
that the bead may be formed from multiple, disconnected segments extending
around the
inner tank 14.
In Figures 4-6, a second embodiment of the improved liquid storage container
according to the present invention is designated by the reference numeral 1
OA. The
container I OA is substantially similar to the container 10, except that the
outer tank 12A
does not include the reduced diameter neck 20, as shown in Figures 1-3. An
optional seal
40 may be provided for the containers 10, 1 OA between the shelf 24 of the
outer tank 12,
12A and the rim 34 of the inner tank 14. The seal 40 may be formed of the
appropriate
3
CA 02787547 2012-08-22
material, such as an adhesive hacked foam, to seal the joint between the shelf
24 and the
rim 34. In Figure 5, the seal 40 is shown in a non-compressed state, though it
is understood
that the weight of the tank 14 and the liquid therein will normally compress
the seal 40. As
an alternative to the foam ring 40, the seal may be formed by a caulk bead
applied to the
juncture of the shelf 24 and rim 34.
The inner tank 14 also includes a drip edge 42 on the outer perimeter of the
top 32
to inhibit migration of rain or other moisture between the shelf 24 and the
rim 34.
Anti-rotation means may also be provided on the tanks 12, 12A and 14 to
preclude
rotation of the tanks when nested together. For example, as seen in Figure 6,
one or more
tabs 44 on the rim 34 align or register with corresponding notches 46 on the
shelf 24.
When the tabs 44 are received in the notches 46, the inner tank 14 is locked
against rotation
relative to the outer tank 12, 12A. This anti-rotation lock is useful when a
drain fitting is
provided between the tank sidewalls 18, 30. It is understood that the tab 44
and notch 46
can be reversed on the shelf 35 and rim 34, respectively.
With the containers 10, 1OA of the present invention, the inner tank 12 may be
filled before or after the inner tank 14 is positioned within the outer tank
12, 12A. Thus,
the outer tanks 12, 12A may be used with different inner tanks 14. The outer
and inner
tanks form a double wall construction for the containers 10, 10A so as to
protect the
contents of the inner tank even if the outer tank is damaged. Also, if the
inner tank 14 has
a leak, any liquid draining from the inner tank will be captured in the space
between the
inner tank 14 and the outer tanks 12, 12A, and thereby prevent contamination
of the ground
or area outside the container 10, 1 OA.
The invention has been shown and described above with the preferred
embodiments, and it is understood that many modifications, substitutions, and
additions
may be made which are within the intended spirit and scope of the invention.
From the
foregoing, it can be seen that the present invention accomplishes at least all
of its stated
objectives.
4
