Flange extension for externally detachable drum liner

A flange fitting for attaching to the lid of a drum includes a seal tube having a generally cylindrical main body with a relatively thin wall arid an outwardly radiating frustoconical lip extension. Also included as part of the flange fitting is a standard drum plug flange having a generally cylindrical main body and an outwardly radiating, frustoconical lip. The drum plug flange is sized and shaped so as to fit within the seal tube such that the lip extension and the lip are generally coextensive with each other. These two components are then able to be anchored into the lid of the drum through a punch press operation which simultaneously clamps and crimps both the lip and lip extension into a raised boss recess thereby precluding any preassembly, such as by welding, of the seal tube and drum flange prior to assembly to the drum lid.

BACKGROUND OF THE INVENTION 
The present invention relates in general to drum liner technology wherein a 
barrier film or bag is used to separate the contents within the liner from 
the drum material. More specifically the present invention relates to a 
flange extension for use with an externally detachable drum liner. 
In a 1992 article by Douglas Larson, published in The Chemical Packaging 
Review, Vol. 2, No. 5, January-February, 1992, pages 32-34 the concept of 
an externally detachable drum liner (EDDL) was presented. Mr. Larson 
explains in his article that "EDDL was initially conceived as a method to 
facilitate the removal of tenacious semi-liquid wastes and sediments 
characteristic of many of the hazardous waste shipments in 55-gallon steel 
drums." 
The value of EDDL is to enable the longer cycle of reuse for containers 
that might otherwise reach a point of chemical contamination due to the 
chemical residue left when the contents of the drum are emptied. If the 
residue is such that it is classified as a hazardous chemical or hazardous 
waste, then the chemical residue might result in the 55-gallon drum 
becoming 55 pounds of contaminated packaging material occupying 55 gallons 
of volume. 
The use of a protective liner which is filled with the chemical (contents 
of the drum) will trap the residue in the liner leaving the drum clean and 
uncontaminated. This allows the drum to be handled as "clean" which 
greatly facilitates and simplifies its reuse or recycling. It is of course 
important that the liner and liner material be selected with the requisite 
size, strength and chemical resistance in order to handle the normal type 
and volume of container contents, regardless of the type or volume. While 
a 55-gallon drum has been referenced, the protective liner concept is also 
applicable to plastic and fiber drums, various containers, bags and boxes. 
Another important consideration with this technology is how to secure the 
liner in position relative to the drum or container so that the liner can 
be easily attached, the liner bag filled with the desired chemical 
contents, and thereafter emptied and removed without a risk that the drum 
or container will become contaminated. 
The approach described by Mr. Larson in his article and in his issued U.S. 
Pat. No. 5,154,308 focuses on a 55-gallon metal, open head drum and the 
concept of attaching the liner to the center of the lid of the drum. The 
drum lid is formed with a raised metal boss with an inwardly opening 
clearance channel or groove into which a drum plug flange is installed. A 
seal tube welded or soldered to the drum plug flange is used to receive a 
bag flange with the liner bag attached. A bag support sleeve is disposed 
around the seal tube and an O-ring is used to retain the EDDL to the drum 
lid in a way that allows the EDDL to be sealed closed and easily detached 
from the lid prior to removing the lid from the drum. 
In the context of this EDDL system the present flange extension invention 
is directed to the design of the drum plug flange and seal tube components 
which are part of the assembly securing the liner to the lid of the drum. 
The value of the present flange extension invention, other than being 
suitable for use with the described EDDL system is its lower cost, the 
elimination of special flange inventories and the ability to withstand the 
greater heat which may be present during reconditioning of the drums. 
The use of disposable liners for containers is known in the art and a 
variety of designs have been patented over the years. In some instances 
the liners are flexible and in other designs the liners are more rigid 
requiring disassembly of the drum for removal. In these earlier patents a 
variety of flange and fitting designs are disclosed, though none are 
believed to anticipate the present flange extension invention nor are 
these earlier patents regarded as being so close as to render the present 
invention obvious. 
The following patents are representative of these earlier patented designs: 
______________________________________ 
Patent No. 
Patentee Date Issued 
______________________________________ 
3,219,230 Housz, et al. November 23, 1965 
2,987,216 Fletcher June 6, 1961 
2,989,208 Gibbs, Jr. June 20, 1961 
3,432,070 Carpenter, Jr. et al. 
March 11, 1969 
4,164,304 Roberson August 14, 1979 
4,552,166 Chadbourne, Sr., et al. 
November 12, 1985 
4,635,814 Jones January 13, 1987 
4,653,663 Holtsclaw March 31, 1987 
4,759,459 Bailey et al. July 26, 1988 
4,775,073 Webb October, 4, 1988 
4,993,579 Burchett February 19, 1991 
5,005,726 Robbins April 9, 1991 
5,046,634 McFarlin et al. September 10, 1991 
5,056,680 Sharp October 15, 1991 
5,154,308 Larson October 13, 1992 
3,443,735 Meijers May 13, 1969 
2,338,604 Silveyra January 4, 1944 
3,167,210 Carney, Jr. January 26, 1965 
3,698,595 Gortz et al. October 17, 1972 
3,918,605 Butler Novemebr 11, 1975 
______________________________________ 
SUMMARY OF THE INVENTION 
A flange fitting for attaching to the lid of a drum according to one 
embodiment of the present invention comprises a seal tube having a 
generally cylindrical main body and an outwardly radiating, frustoconical 
lip extension and a drum plug flange having a generally cylindrical main 
body and an outwardly radiating, frustoconical lip, the drum plug flange 
being sized and shaped to fit within the seal tube such that the lip 
extension and the lip are generally coextensive with each other. 
One object of the present invention is to provide an improved flange 
fitting for attaching to the lid of a drum. 
Related objects and advantages of the present invention will be apparent 
from the following description.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
For the purposes of promoting an understanding of the principles of the 
invention, reference will now be made to the embodiment illustrated in the 
drawings and specific language will be used to describe the same. It will 
nevertheless be understood that no limitation of the scope of the 
invention is thereby intended, such alterations and further modifications 
in the illustrated device, and such further applications of the principles 
of the invention as illustrated therein being contemplated as would 
normally occur to one skilled in the art to which the invention relates. 
Referring to FIG. 1 there is illustrated a drum lid 20 being lifted off of 
a 55-gallon metal drum 21 to reveal an externally detachable drum liner 
(EDDL) 22. The drum liner 22 includes a flexible plastic bag 22a which is 
attached at the center of the drum lid to a raised, generally cylindrical 
boss 23. Drum liner 22 includes a rigid rim assembly 24 and securing the 
rim assembly 24 of the drum liner 22 and the lid 20 together is a flange 
fitting 25 (see FIG. 2). Flange fitting 25 is designed such that the drum 
liner 22 can be detached from the lid prior to removing the lid from the 
drum. The drum lid 20 includes a standard 3/4" vent plug 28 located in its 
normal position near the rim 29 of the lid 20. 
The general structure of an earlier EDDL system, not incorporating the 
present invention, is disclosed in U.S. Pat. No. 5,154,308, issued Oct. 
13, 1992 to Larson. This U.S. Patent to Larson is hereby expressly 
incorporated by reference for its overall disclosure. 
Referring to FIG. 2, the assembly of the drum liner rim assembly 24 and the 
flange fitting 25 is illustrated in greater detail as a full 
cross-sectional view. Before describing the particulars of the flange 
fitting 25 and rim assembly 24, it should first be noted that a generally 
cylindrical rubber sleeve 32 is employed in the assembly of the drum liner 
to the raised boss. Sleeve 32 fits around the outer wall surface of flange 
fitting 25 and functions more as a filler or spacer in order to prevent 
any portion of the liner bag 22a from interfering with the snap fit 
assembly of the rim assembly 24 and flange fitting 25. 
Rim assembly 24 includes an annular bag flange 33 including a lower, 
outwardly radiating underside surface 35 to which bag 22a is heat sealed. 
As is illustrated in FIG. 3, bag 22a extends up and across underside 
surface 35 of bag flange 33 at which point it is heat sealed so as to 
create a liquid tight and secure assembly of the liner bag 22a and bag 
flange 33. Sleeve 32 has also been illustrated in FIG. 3 simply to show 
how the outer lip of bag 22a extends up and around the outside surface of 
sleeve 32 thereby spacing it from the remainder of the rim assembly 24 and 
flange fitting 25. 
The flange fitting 25 (see FIG. 4) includes annular drum plug flange 38 and 
generally cylindrical seal tube 39. These two members have a generally 
concentric, close fitting but free relation to each other. The seal tube 
39 includes an O-ring channel 40 and a frustoconical lip extension 41. The 
generally cylindrical main body portion of seal tube 39 is of a unitary 
construction with the frustoconical lip extension 41. The drum plug flange 
38 also includes a generally cylindrical main body portion which is 
internally threaded for the receipt of a drum plug and is of unitary 
construction with the main body portion is an upwardly and outwardly 
radiating frustoconical lip 42. It is to be understood that the flange 38 
constitutes what the inventors regard as the normal or standard flange 
which is typically used with containers and drums of the type illustrated 
and is typically anchored into the raised boss by a punch press operation 
including both vertically compression and inwardly directed radial jaws as 
illustrated in FIG. 7. 
As is illustrated in FIG. 4, the lip extension 41 is sized and arranged to 
fit closely up and around the frustoconical lip 42 of the drum plug 
flange. As illustrated, the lip of the drum plug flange and the lip 
extension of the seal tube are closely sized to one another with a free, 
though close fit such that the lip and lip extension are coextensive with 
each other. In this regard it will also be noted that the upper outer 
edges of the lip and lip extension are adjacent with really no overlap by 
either member relative to the other. 
According to the present invention, both the drum plug flange and the seal 
tube will be installed into the inwardly opening channel or recess in the 
raised boss and by means of the normal punch press operation including 
both vertical compressive forces and inwardly directed radial clamping 
forces, these two members will be locked together, simultaneously, into 
the raised boss. Once this procedure is performed, the drum plug flange 38 
and seal tube 39 become firmly locked in place and in effect become an 
integral part of the steel drum lid. 
As should be understood, the use of the mechanical punch press operation 
can be performed on both the drum plug flange 38 and seal tube 39 without 
those parts having to be fixed together in some preliminary relationship. 
These two members do not have to be initially bonded, soldered, welded or 
otherwise attached to each other. All that is required is that the drum 
plug flange be set down inside the seal tube so that the frustoconical lip 
42 of the flange and the lip extension 41 of the seal tube are oriented so 
as to be coextensive with each other. It will also be noted that the outer 
edge of the frustoconical lip is formed with a series of outwardly 
radiating projections, equally spaced with recess notches inbetween. The 
radial clamping forces which occur simultaneously with the vertical 
compressive forces as part of the punch press operation utilize these 
indentations in order to securely attach the flange and seal tube into the 
raised boss in a secure manner such that these components are not able to 
turn or rotate in the raised boss. 
With the lid of the drum initially removed from the drum, the drum plug 
flange 38 and seal tube 39 are securely installed into the raised boss by 
the one-step punch press operation as mentioned. This first assembly step 
creates the structure that is illustrated in FIG. 5. Another preliminary 
step which may be performed at any time relative to the timing of the 
punch press operation is to assemble the bag 22a to the bag flange so as 
to create rim assembly 24. It is of course important to first install the 
bag support sleeve 32 over the seal tube so that this sleeve will be in 
position when rim assembly 24 is snapped into position. Although not 
illustrated in FIG. 3, an O-ring 46 is used to control the assembly and 
the detachable nature of the rim assembly from the flange fitting. 
Consequently, O-ring 46 could be regarded as part of rim assembly 24 since 
the O-ring 46 is installed in the bag flange 33 prior to snapping the rim 
assembly 24 into the flange fitting 25. As is illustrated, O-ring 46 fits 
within annular channel 47 (see FIG. 3) which is formed in bag flange 33. 
As has been illustrated and described, the seal tube 39 includes the 
O-ring channel ring 40 and the assembly process involves pushing upwardly 
on the rim assembly, including O-ring 46 so that the outer edge of the 
O-ring 46 slides along the inside diameter surface of the seal tube until 
such time as the O-ring 46 encounters the inwardly-open which is adjacent 
to lower end 48. At this point the O-ring 46 effectively snaps into the 
O-ring channel 40 and the rim assembly is now assembled to the flange 
fitting 25. 
As illustrated, the lower, generally cylindrical end 48 of the seal tube 
extends downwardly below the O-ring 46 but is sized such that the bottom 
edge of the seal tube does not bottom out on the top surface 49a of lower 
lip 49 of bag flange 33 before the O-ring 46 snaps into position in O-ring 
channel 40. Likewise, bag support sleeve 32 has a length in the axial 
direction which does not interfere with the assembly process. 
The next step in the assembly procedure is to assembly the lid onto the 
drum. The vent plug 28 is opened (removed) and the bag 22a is inflated by 
means of a low pressure, high volume air pump, such as a shop vacuum 
blower. The bag is sized large enough that the drum contents are 
restricted only by the drum and not by any portion of the bag. This 
oversizing of the bag so as to eliminate any loading on the bag and thus 
any loading on the rim assembly/flange fitting assembly is important 
because the only assembly feature which holds the bag in position is the 
interfit of the O-ring 46 between the O-ring channel 40 in the seal tube 
and the O-ring channel 47 in the bag flange 33. After the bag is inflated, 
the vent plug is closed (installed) and the drum is ready to be filled. 
As illustrated in FIG. 2 an externally threaded drum plug 50 is received by 
the internal threads of the drum plug flange 38 in order to seal the drum 
closed after filling. Gasket 51 provides additional security for the seal. 
Plug 50 provides the means of opening and closing the drum as some or all 
of the drum contents are required. Once the drum is empty, the drum liner 
(EDDL) is sealed closed with a bag plug 52, see FIG. 6. The drum liner can 
then be detached from the flange fitting by exerting a downward force of 
approximately 45 pounds around the upper, outer edge of the bag plug 52. 
The exerted forces on the bag plug 52 press down on the upper edge of the 
O-ring channel 47 causing the bag flange 33 to come out of engagement with 
the seal tube. The result is that the rim assembly including the O-ring 46 
will be disassembled and actually detached from the flange fitting. 
Consequently, the drum liner will be detached from the drum lid and is 
effectively free within the drum 21. 
The next step is to remove the drum lid from the drum and then dispose of 
the contaminant-residue trapped in the liner bag 22a as the entire liner 
22 is discarded. The lid 20 and drum 21 are then ready to receive a new 
liner with the same snap fit O-ring assembly technique. Thus the drum can 
be used and reused and reused, without the risk of chemical or hazardous 
waste contamination. Disposing of 100 liners as compared to 100 drums 
results in a dramatic decrease in hazardous waste and a dramatic decrease 
in storage or landfill requirements. 
The design efficiency provided by flange fitting 25 is the focus of the 
present invention. The original design for the flange fitting used a roll 
formed seal tube soldered (or welded) to a standard drum flange. The 
standard drum flange was then mechanically affixed to the drum head 
(raised boss) by the normal or conventional punch press operation. The 
raised boss includes an inwardly opening recess 56 into which the flange 
lip is installed. According to the original design approach, the upper 
outwardly extending lip of the standard drum flange would be anchored in 
position within the annular recess 56 by both vertical compression during 
the punch press operation while at the same time five radially positioned 
jaws press inwardly so as to securely lock the metal of the raised boss of 
the lid in and around the various projections and recesses in the outer 
edge of the flange lip. It is acknowledged that this earlier design and 
the corresponding punch press operation are conventional and typical of 
what has been done with this type of standard drum flange for a number of 
years. 
With regard to using this concept in combination with the disclosed 
externally detachable drum liner (EDDL), it was necessary to provide and 
to assemble some type of seal tube which could be used to provide O-ring 
channel 40. While there was no need or desire to change the standard 
flange, nor was there any desire to change the flange installation 
procedure so that the existing punch press tooling and dies could be used, 
certain disadvantages were noticed with regard to the original design for 
the seal tube. First, the original design for the seal tube involved 
simply a generally cylindrical sleeve and there was no lip extension. 
Consequently, the seal tube had to be attached to the drum plug flange by 
some means and the method selected was welding or soldering in order to 
initially join these two components together so that the seal tube would 
have a secure and fixed relationship to the drum plug flange and the drum 
plug flange would then be anchored into the raised boss. This welding or 
soldering step for joining the seal tube and drum flange together had to 
be performed before a drum manufacturer would assemble the drum plug 
flange to the drum lid. Since drum manufacturers prefer not to perform 
this welding or soldering step and since many of the drum manufacturers 
are not equipped to perform this step, this original design resulted in a 
double inventory of drum flanges. Two styles needed to be stocked by the 
drum manufacturer, one inventory of the conventional drum plug flange for 
use with standard drum lids and a second inventory of specially welded or 
soldered flange and seal tube assemblies for use with drum lids intended 
for use with the EDDL system. It should be understood that the drum 
manufacturers will produce a wide range and variety of drums with 
different features and design styles. Consequently, since any one drum 
manufacturer might be producing a number of non-EDDL drums as well as a 
number of EDDL drums, it would be necessary to have the standard drum plug 
flange available both as a single component and as a welded assembly. 
Another disadvantage of the original design approach pertains to the 
material thickness needed for the seal tube and the fact that tube stock 
had to be used. The tube stock used is rolled and a bulging die is used to 
create the O-ring channel 40. This tube stock is substantially thicker 
than what is used in the present invention, having a wall thickness of 
approximately 0.060 inches or slightly thicker. This thickness of material 
is necessary because of the welding step and a concern about warpage of 
the steel tube and flange. With thicker material there is less risk of 
warpage to an unacceptable level. Warpage of the seal tube might also warp 
or distort the drum plug flange which could affect the internal threads. 
Warpage of the seal tube might also affect the degree of cylindricity of 
the seal tube and the ability of the O-ring channel 40 to properly receive 
the O-ring 46 in order to assemble the rim assembly 24 into the flange 
fitting. A third concern, though one also related to the temperature 
level, pertains to reconditioning of the drums. Reconditioning of a drum 
typically exposes the lid and the assembled seal tube and flange to 
temperatures in the range of 500.degree.-900.degree. F. If solder is used 
as the "welding" medium in order to join the seal tube and flange 
together, the solder softening temperature in the range of 
400.degree.-450.degree. F. would present a problem during drum 
reconditioning. These temperature ranges would mean that during 
reconditioning the soldered joint would loosen or break free requiring 
another process step to resolder the seal tube and flange back together. 
Obviously this problem could be avoided by going back to a welded joint, 
but here again in order to prevent the undesirable and conceivably 
unworkable warpage it is important that a relatively thick wall be used 
for the seal tube. 
The present invention provides improvement in the design of the flange 
fitting assembly by eliminating any welding or soldering step and simply 
crimping both the seal tube 39 and drum plug flange 38 into the raised 
boss 23, simultaneously by a single punch press operation. The present 
invention still uses the standard drum plug flange and thus drum 
manufacturers can stock a single flange for both EDDL drums and for 
non-EDDL drums. 
The seal tube is now able to be made of thinner sheet stock material and 
stamped out of the sheet stock prior to forming. A typical wall thickness 
for this sheet stock for the seal tube of the present invention is 0.028 
inches. The O-ring channel 40 can be formed into the sheet stock and a 
bulging die is not required. Reconditioning temperatures are not a factor 
with this new design according to the present invention as there is no 
solder to soften and warpage is not a concern since welding temperatures 
are not present. 
The key feature of the present invention which is different from the 
original design approach is to modify the seal tube from a generally 
cylindrical member to a combination of a generally cylindrical member with 
an integral, upwardly and outwardly radiating frustoconical lip extension 
41 which is sized and shaped to fit closely around and conform to the size 
and shape of flange 38 and in particular to the frustoconical lip 42 of 
flange 38. These two overlapping and aligned lips (lip extension 41 and 
lip 42) are installed together, though as loose pieces, into the annular 
recess 56 of the raised boss 23. The lip 42 and lip extension 41 are 
positioned in contact with each other and are sized and shaped so as to be 
coextensive with each other. The punch press operation of FIG. 7 is then 
performed securely clamping the flange and seal tube simultaneously into 
the raised boss of the drum lid 20. 
The punch press set up includes a movable male portion 60 and a stationary 
female portion 61. Located as part of the male portion are a total of five 
crimping arms 62 which are equally spaced around male portion 60. Each arm 
62 is spring biased and has a geometry and orientation which results in 
radially inward movement as the male portion advances. These arms must 
move inwardly to create clearance for the arms to move upwardly as the 
male portion advances. 
Central die 63 compresses the top surface of the raised boss 23 so as to 
crimp the lip 42 and lip extension 41 into the open recess 56. As this 
action occurs, the five arms push inwardly so as to create an underside 
surface of the raised boss around the lip and lip extension. This 
underside crimping action of the arms also crimps the metal of the raised 
boss 23 into and around the various projections and recesses in the flange 
lip. 
While the invention has been illustrated and described in detail in the 
drawings and foregoing description, the same is to be considered as 
illustrative and not restrictive in character, it being understood that 
only the preferred embodiment has been shown and described and that all 
changes and modifications that come within the spirit of the invention are 
desired to be protected.