Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF THE INVENTION
The present invention relates to lining arrangements for
receptacles such as cylindrical steel drums or barrels or
other containers for liquids or particulate materials.
BACKGROUND TO THE INVENTION
Cylindrical steel drums conventionally have end walls
sealingly fixed to a cylindrical side wall with flanges
provided in one of the end walls receiving screw plugs s
that the contents may be filled and discharged through the
flanged opening. For many products a lining such as a
plastic-type lining is required to protect the structure of
the drum from contacting the contents. One known method of
applying a suitable inert coating to the interior of such a
drum is to melt a plastic coating onto the interior surfaces
of the drum while rotating the drum at elevated temperature,
a particulate supply of material for forming the plastic
coating being first inserted into the drum.
Another approach has been to manufacture blow-moulded
free-standing plastics liners which are placed inside the
drum during its assembly and before the drum is shipped to
the customer. Such liners, however, are expensive and a
problem has existed with respect to the replacement of the
liner when the drum is reconditioned. Since the liners are
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blow-moulded free-standing liners, the wall thickness is
relatively large and rigid and thus transportation and
storage of these liners is very expensive.
With this problem in mind, it has also been proposed
to manufacture a liner which, although being relatively
heavy and having a substantial wall thickness, is designed
to be foldable to reduce storage and transportation
volume, However, such liners have creases at the folds
and these creases are difficult to remove and may initiate
premature failure of the liner.
The limitations of the previous proposals are such
that new and useful alternatives would be desirable.
SUMMERY OF THE INVENTION
According to the present invention there is provided
an improved lined receptacle comprising, in combination:
a rigid, enclosed container having a cylindrical side
wall, an attached bottom wall, and a top wall, said top
wall having an interior side and an exterior side, said
top wall defining two opposed pairs of spaced openings,
each of said two opposed pairs including a first gland
opening and a second gland opening, said top wall further
having first and second skirts extending outwardly from
said exterior side and enclosing said first and second
gland openings, respectively;
a flexible liner adapted to substantially fill said
rigid, enclosed container, said liner comprising first and
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second opposed, overlying, flexible, rectangularly shaped
panels of a film material, said panels sealed at the edges
thereof and also sealed across the corners to define a bag
enclosure;
first and second gland members sealingly attached to
field flexible liner, one of said glans members briny
attached to the first panel and the other gland member
being attached to the second panel, said gland members
being separated by a seal along an edge of the panels and
0 in an opposed relationship;
said gland members adapted to engage said two opposed
pairs of spaced openings by projecting through the first
and second gland openings, respectively, whereby said
flexible liner is draped between said two opposed pairs of
openings along said interior side of said top wall so as
to facilitate filling and draining of said improved
receptacle;
each of said first and second gland members including
a base sealed to said flexible liner, a spigot extending
from said base opposite said flexible liner, and a spout
extending from said base opposite said flexible liner;
said spigot of each gland member having a spigot head
and a spigot neck so as to snap fit into said first gland
opening from said interior side of said top wall and
outwardly directed, said first skirt engaging said spigot
neck and abutting said spigot head;
said spout of each gland member having a spout head
and a spout neck so as to snap fit into said second gland
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opening from said interior side of said top wall and
outwardly directed, said second skirt engaging said spout
neck and abutting said spout head. each of said spigots
defining means of maintaining a gland member and attached
liner in a torque resisting position with the sealed edge
of the liner maintained intermediate the gland members and
supported between the gland members:
food spout and said base providing a fluid passage
between the interior of said flexible liner and said
exterior side of said top wall;
seal means for selectively closing said fluid
passage; and
release vent means in said top wall for selectively
relieving pressure between said rigid, enclosed container
and said flexible liner, said vent means being centrally
located between the pairs of gland openings.
Most preferably each of said glands is a plastic
mounding having a reduced external diameter neck portion
extending away from the flexible liner to an enlarged head
and the wall portion has its aperture provided by an
outwardly projecting substantially cylindrical skirt-like
structure of axial length corresponding to that of the
neck of the gland, the neck of the gland being fitted by
snap action by being pressed through the aperture whereby
and peripheral tip of the squirt engages under the head of
the gland.
The gland may have an internal screw-thread in the
neck for receiving a closure plug or other fitting.
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Very advantageously, two such glands are provided and
interconnected with the wall porn on opposite sides
-thereof, one gland being adapted to be opened to empty
ingress of air within the liner whilst the contents are
discharged through the other gland.
It will be appreciated that the material forming the
flexible liner can be chosen to suit the intended contents
and the material could be simply a film of plastics
material, a single or multi-ply structure and indeed could
be a laminate. One important application of the invention
is to the case where the liner is of a laminate about 125
microns thick with an interior layer of highly flexible
relatively inert plastics material (such as polyethylene)
and a exterior layer of a relatively tough and durable
material (such as nylon). For example, a polyethylene
interior layer of about 100 microns may be used with
advantage together with an exterior nylon layer of about
25 microns thickness.
However, many other structures may be advantageous
for particular applications.
One highly effective form for the air discharge means
is a screw-threaded aperture provided in the wall portion
and adapted to be closed by a screw-plug having sealing
engagement.
The invention can be most advantageously and
economically implemented by the use of a thin walled liner
and, furthermore, for a given receptacle design, a range
of liners suitable or different products can readily be
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provided. Furthermore, the nature of the liner permits a
compact liner to be provided for storage and transportation
purposes, yet a highly effective and reliable product can be
achieved. By virtue of the combination of features
according to the invention an effective and economic result
can be achieved, the walls of the receptacle providing
structural characteristics with the liner acting as a
reliable barrier. By virtue of the liner being held in
substantially intimate contact over the interior walls of
the receptacle, the risk of liner damage due to relative
movement between it and the interior walls is minimized.
Furthermore, when it is desirable to recondition a drum
it can be a relatively simple process to fit a replacement
liner after the receptacle has been opened by removal of the
wall portion from the body portion.
GRIEF DESCRIPTION OF THE DRAWINGS
For illustrative purposes only, examples of the
invention will now be described with reference to the
accompanying drawings of which:
Figure 1 is a perspective view of a receptacle with
liner in accordance with a first embodiment of the invention;
Figure 2 is an elevation Al view of the liner used in
Figure 1 but shown on a reduced scale;
Figure 3 is a plan view of a gland for the liner of
Figure 2 but to an enlarged scale;
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Figure 4 is a cross-sectional view on the line I of
Figure 3; and
Figure 5 is a perspective view of a second embodiment of
a receptacle with a liner therein.
DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 shows a receptacle in the form of a cylindrical
steel drum (10) having installed wherein a flexible plastic
liner shown in more detail in Figure 2 and secured to a top
en wall tl3) of the drum by two plastic glands I shown
in more details in Figures 3 and 4. The drum (10) is of
conventional form and has a sheet metal side wall (12)
having at each end an outwardly directed bead with which the
top and bottom end walls (13 and 14) are interconnected by a
sealed seam effected by rolling.
On diametrically opposite sides of the top end wall.
these are a pair of large openings (15) and small openings
(`16) respectively provided by axially outwardly directed
skirts having a sharp shoulder with which the glands (44)
are fitted as described in more detail below. Centrally
located in the top end wall (13) is a venting opening (17)
pitted with a screw-threaded flange for accommodating a
screw-threaded sealing plug which is not shown in the
drawing. The flange has a polygonal shoulder accommodated
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in a corresponding shaped interior recess in the end wall
for providing torque resistance.
The liner (11) shown in detail in Figure 2 is of
bag-like form and is illustrated when laid out flat and
viewed in elevation, the respective sides being similar and
comprising front and back panels (40,41) having respective
apertures around which a respective gland (~) is attached
as described below, the panels being heat sealed together
along their respective edges (45). Furthermore, to
facilitate discharge of liquids from the liner when
installed in a drum, liquids are preventing from reaching
the corners of the bag-like structure by provision of
subsidiary heat seals (46) directed across the corners of
the bag.
The panels (40,41) can be of any suitable material which
may be plastic film (slither single ply or multi-ply
structure) or if desired may be of or include laminated
materials. For example, good results have bee obtained
from the use of a single ply laminated sheet of about 125
microns thickness with the inner layer of the panel being
polyethylene about 100 microns thick and the outer layer
being about 25 microns thick and of nylon. Another useful
structure is obtained by a laminate having an interior layer
of polyethylene film of about 50 microns thick and the outer
layer itself being a laminate about 75 microns thick. This
outer layer can be a laminate structure having the layer
directed towards the inner layer of the easel being of
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polyethylene and about 50 microns thick whereas the outer
layer of this laminate facing the exterior of the liner
being about 25 microns thick and of the nylon.
Referring now to Figures 3 and 4, each gland (44) is an
injection mounded component of thermoplastic material such
as polyethylene and has a pear-shaped base (51) from which a
pear-shaped outwardly directed flange (50) projects so that
a portion ox the panel (40 or 41) surrounding its opening
may be welded to the underside of the flange (50).
An upstanding internally screw-threaded cylindrical
projection (52) extends from the base (51) and has a reduced
diameter the neck (53) terminating in a shoulder (55) and
leaving a larger diameter head (54). This cylindrical
projection can be fitted with a screw plug to close the bag
and particulate or liquid material can be introduced into
the bag or discharged therefrom readily.
A relatively small diameter upstanding spigot (57) also
extends from the base (51) and is hollow but is integrally
formed with a top cap I which provides an outwardly
directed enlarged head for the spigot. The spigot (57)
and the cylindrical projection (52) carry respective 0-ring
seals (60 and 59) and each gland ~44) is fitted and secured
to the top end wall (33) by snap-fitting respectively the
projection (52) and spigot (57) through the openings (15
and 16?. The upstanding skirt defining these openings snap-
fits over the head (54) of the projection (52) and over the
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top cap (58) of the spigot (57) to engage tightly and
establish a seal. The spigot (57) has a torque resisting
function when a screw plug is inserted or removed from the
cylindrical projection (52).
Figure 5 shows a second embodiment in which like parts
have been given like reference numerals. the distinction of
the embodiment of Figure 5 being that an alternative
configuration is provided for attachment of the top end wall
(66) to the side wall (65). Whereas the drum of Figure 1 is
known as a "closed head drum", the drum of Figure 5 is known
as an "open head drum" since the top end wall (66) is simply
clamped into position, the periphery of the top end wall
having a rolled over skirt which engages over a
corresponding outwardly directed bead at the top end of the
side wall (65): a clamping ring (67) is fitted over the
assembly and tightened by means of a nut (68) and bolt
(69). It is best to locate some sealing material between
the faces of the end wall (66) and side wall (65) which are
to contact one another.
Assembly of the combination of the receptacle with the
liner in both the described embodiments is similar in that
the liner (11) is secured by snap-fitting the glands (44)
through the respective openings in the top end wall for the
drum, the lands being located so as to be within the drum
US when assembly is completed and then the top end wall with
the attached liner is secured to the side wall of the drum.
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A screw-threaded plug is sealingly engaged in one of the
glands and compressed air introduced through the other gland
to expand the liner as generally indicated in Figures 1 and
5 by the arrows and the reference "kiwi" referring to
compressed air. Figures 1 and 5 show the line just before
complete expansion has occurred. Air from between the liner
and the interior ox the drum wall escapes through the
opening (17) as the liner is expanded and when the liner has
been pressed into intimate contact with the interior walls
of the drum, a closure plug is screw-threadably engaged in
the opening (17) to prevent return of air.
The liner may now be filled with contents and upon
subsequent discharge of the contents a partial vacuum is
maintained 80 that the liner is retained in substantially
intimate contact with the interior surfaces of the drum.
The invention can be applied to embodiments in which the
liner it adapted to hold contents within a large range, for
example 10 liters to 300 liters. The material chosen for
the glands and the liner is selected to suit the material to
be packaged, polyethylene being readily available, useful
and relatively cheap material for many purposes but may be
substituted where required to suit specific products.
