Abstract:
A method of packing a package in an overpack salvage drum that includes a drum body for holding the package to be overpacked, a lid adapted to be rotatably threaded onto the drum body to seal the package held in the drum body therein, and a clip adapted to be operatively associated with the lid before the lid is rotatably threaded onto the drum body. The method includes placing the package into a drum body, operatively associating a clip to a lid that is adapted to be rotatably threaded onto the drum body, and rotatably threading the lid with the clip operatively associated therewith onto the drum body to seal the package therein, wherein the clip is adapted to break in preference to the lid and the drum body when the seal between the lid and the drum body is first compromised.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a division of U.S. application Ser. No. 12/464,616, filed May 12, 2009, now U.S. Pat. No. ______. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates to a method of overpacking a package using an overpack salvage drum that includes a drum body for containing the package and a lid for sealing the package within the drum body. More particularly, the present invention relates to a method of overpacking a package using an overpack salvage drum that includes a clip for indicating whether the seal between the drum body and the lid has been compromised. 
         [0004]    2. Description of Related Art 
         [0005]    The U.S. Department of Transportation (“USDOT”) has established regulations for removable head salvage drums (see, e.g., 49 C.F.R. §1.173(c)), which are also known in the art and hereinafter referred to herein as overpack salvage drums. Overpack salvage drums are used in a variety of applications, including for the containment of packages that have been damaged, have otherwise become defective or have been found to be leaking and/or for the containment of potentially hazardous solid materials while they are being transported. Shaw et al., U.S. Pat. No. 4,708,258, discloses a rotationally molded polyethylene overpack salvage drum that meets such USDOT standards. 
         [0006]    The overpack salvage drum according to Shaw et al. includes a single-walled drum body having an open end and a double-walled lid that is adapted to threadingly engage the open end of the drum body and thereby seal and contain a steel drum therein. A closed-cell foam gasket in the lid seals the closure between the lid and the drum body. One of the features of the overpack salvage drum according to Shaw et al. is that the lid can be selectively threaded onto and removed from the drum body. However, there are some applications in which it would be highly desirable to be able to readily determine whether the seal between the lid and the drum body has been compromised. This is not possible with the overpack drum according to Shaw et al. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    In view of the foregoing, the present invention is directed toward a method of packing a package within an overpack salvage drum that includes a frangible clip that is operatively associated with the lid and engages with one or more structures protruding from the drum body when the lid is sealingly engaged with the drum body. Subsequent removal of the lid from the drum body causes the clip to fracture thereby making it evident that the integrity of the original seal has been compromised. 
         [0008]    In a preferred embodiment of the invention, the lid is adapted to threadingly engage the open end of the drum body and thereby seal and contain a package therein. In such embodiment, the frangible clip is adapted to be connected to the lid before the lid is threaded onto the open end of the drum body. The frangible clip includes a tail portion that extends below an annular skirt portion of the lid when the clip is connected to the lid. An outer portion of an intermediate side wall portion of the drum body is provided with a plurality of projections. At least one of the plurality of projections includes a camming surface for contacting and lifting the tail portion of the clip over the projection when the lid is threaded onto the drum body. The projection also includes a non-camming blocking surface that is adapted to contact the tail portion of the clip and thereby prohibit the lid from being unthreaded from the drum body. Preferably, when the lid and clip assembly is threaded onto the drum body, the tail portion of the clip cams sequentially over and past a plurality of projections until the lid reaches a predetermined point wherein the lid is optimally aligned on the drum body, thereby substantially permanently overpacking the package placed therein. Once the lid is secured to the drum body with the tail portion of the clip retained against the non-camming blocking surface of the projection, the lid cannot be removed from the drum body without producing evident damage to the clip, the lid and/or the drum body. The clip is preferably made of a frangible plastic material, which will fracture when force is applied to it. 
         [0009]    The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the present invention may be employed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a preferred embodiment of an overpack salvage drum according to the invention. 
           [0011]      FIG. 2  is an exploded perspective view of the overpack salvage drum shown in  FIG. 1 . 
           [0012]      FIG. 3  is a top plan view of the overpack salvage drum shown in  FIG. 1 . 
           [0013]      FIG. 4  is a side section view of the overpack salvage drum taken along the line IV-IV in  FIG. 3 . 
           [0014]      FIG. 5  is an enlarged portion of the section view shown in  FIG. 4 . 
           [0015]      FIG. 6  is perspective view of the lid of the overpack salvage drum shown in  FIG. 1  with the clip retained in a pre-use condition. 
           [0016]      FIG. 7  is an exploded perspective view of a portion of a bottom side of the lid of the overpack salvage drum shown in  FIG. 6 . 
           [0017]      FIG. 8  is a perspective view of the overpack salvage drum shown in  FIG. 1  showing the bottom side thereof. 
           [0018]      FIGS. 9A ,  9 B and  9 C show a partial perspective view, a section view and an enlarged section view, respectively, of an alternative gasket arrangement for an overpack salvage drum according to the invention. 
           [0019]      FIG. 10  is a partial perspective view of an optional tamper-evident feature of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    A preferred embodiment of an overpack salvage drum  10  for use in accordance with the method of the invention is shown in  FIGS. 1-8 . The overpack salvage drum  10  comprises a drum body  20 , a lid  30  and at least one clip  40 . The drum body  20  is adapted to receive and contain a package. The lid  30  is adapted to be secured to the drum body  20  to seal that package within the volume defined by the drum body  20  and the lid  30 . And, the clip  40  is adapted to inhibit removal of the lid  30  from the drum body  20 . Throughout the instant specification and in the appended claims, the term “package” thus refers to any solid material that may be contained within the overpack salvage drum  10  including, but not limited to, containers (e.g., metal drums or plastic drums etc.) that may contain liquids or solids or a combination of liquids and solids, solid manufactured parts (e.g., piping and fittings etc.) and other solid materials (e.g., contaminated soils etc.). 
         [0021]    The drum body  20  and lid  30  are preferably formed of a durable, chemical resistant polymer such as, for example, linear low density polyethylene (LLDPE). However, it will be appreciated that other suitable polymers can be used, if desired. The drum body  20  and the lid  30  can be formed by rotational molding or other polymer molding process. 
         [0022]    The clip  40  is preferably made of a frangible material. As used herein, the term “frangible” means that the material is more likely to fracture upon being exposed to force rather than it is to deform plastically and then regain its original appearance after the force is removed. Preferably, the frangible material is a polymer, but one that is more brittle than the polymer used to form the drum body  20  and the lid  30 . High density polyethylene (HDPE) can be used, for example. The clip  40  is preferably formed by injection molding or other plastic molding process. 
         [0023]    With particular reference to  FIG. 2 , the drum body  20  is preferably a single-walled structure that comprises a solid, side wall  50  that tapers outwardly from a bottom wall  60  and an open end  70 . The bottom wall  60 , which is discussed in greater detail below, and the side wall  50  are preferably substantially circular. The side wall  50  preferably comprises an upper side wall portion  80 , an intermediate side wall portion  90  and a lower side wall portion  100 . The intermediate side wall portion  90  is disposed between the upper side wall portion  80  and the lower side wall portion  100  and has a diameter that is greater than the diameter of both the upper side wall portion  80  and the lower side wall portion  100 . 
         [0024]    A plurality of substantially vertical intermediate side wall recesses  110  are preferably formed in the intermediate side wall portion  90 . The intermediate side wall recesses  110  strengthen the intermediate side wall portion  90  of the drum body  20 . The intermediate side wall recesses  110  preferably do not extend the full height of the intermediate side wall portion  90 , which allows the drum body  20  to flex during impact. 
         [0025]    A plurality of substantially vertical lower side wall recesses  120  are also preferably formed in the lower side wall portion  100 . The lower side wall recesses  120  strengthen the lower side wall portion  100  of the drum body  20 . Like the intermediate side wall recesses  110 , the lower side wall recesses  120  also preferably do not extend the full height of the lower side wall portion  100  in which they are disposed, which allows the drum body  20  to flex during impact. 
         [0026]    At least one thread  130  is provided on an exterior circumferential surface of the upper side wall portion  80 . Two or more threads  130  can be used, if desired. It will be appreciated that the depth, pitch and width of the threads will be determined in view of the size of the overpack salvage drum  10 . Preferably, the threads  130  allow the lid  30  to rotate 720° from a starting position to a fully seated position. 
         [0027]    The inside diameter of the upper side wall portion  80  of drum body  20  is preferably greater than the outer diameter of the lower side wall portion  100  of the drum body  20 . Thus, the lower side wall portion  100  of a first drum body  20  may be received within the upper side wall portion  80  of a second drum body  20 . This allows several empty drum bodies  20  to be nested together, one inside the other, in a stacked arrangement, which minimizes shipping space and storage space prior to use. 
         [0028]    A lower annular shoulder  140  is formed on drum body  20  between the intermediate side wall portion  90  and the lower side wall portion  100 . The lower annular shoulder  140  preferably defines a hemispherical or conical surface that serves as a self-centering annular groove for the upper edge  150  of a drum body  20  when two or more drum bodies  20  are nested together in a stack prior to use. The lower annular shoulder  140  can be used to lift the drum body  20  or a filled overpack salvage drum  10  (e.g., via the use of the forks of a lift truck). 
         [0029]    The vertical recesses  110 ,  120  prevent the formation of a vacuum and thus make it easier to separate the top-most drum body  20  from a stack of drum bodies  20 . An upper annular shoulder  160  is also formed on the drum body  20  between the intermediate side wall portion  90  and the upper side wall portion  80 . 
         [0030]    With reference to the accompanying figures, the lid  30  is preferably a double-walled structure. An annular skirt  170  (see  FIG. 9B ) extends downwardly from the perimeter of a substantially horizontal, circular double-walled body  180  of the lid  30 . At least one recessed thread  190  (i.e, a groove) is formed on an inside circumferential surface of the annular skirt portion  170 . The recessed thread  190  is adapted to threadingly engage (i.e., receive) the at least one raised thread  130  formed on the exterior circumferential surface of the upper side wall portion  80  of the drum body  20 . The use of at least one raised thread  130  on the drum body  20  and at least one recessed thread  190  on the lid  30  is preferred because in the event that pressure were to build up within the drum body  20 , such a thread configuration would tend to tighten the connection between the lid  30  and the drum body  20 . But the opposite arrangement could be used, if desired. It will be appreciated that the number, pitch, depth and width of recessed threads  190  will correspond to the number, pitch, depth and width of the raised thread  130 . 
         [0031]    Preferably, the double-walled body  180  of the lid  30  is provided with a plurality of “kiss off” portions  200 , which can be formed in any desirable shape or pattern. The “kiss off” portions  200  are preferably arranged across the lid to improve the strength of the lid  30 . The “kiss off” portions  200  are formed where the two spaced-apart walls of the double-walled body  180  are brought together to form a single wall at discrete locations on the lid  30 . “Kiss off” portions  200  provide additional rigidity for the double-walled body  180  of lid  30 . It will be appreciated that the number and location of “kiss off” portions  200  will be dependent upon the dimensions of the overpack salvage drum  10 , which is dependent upon the dimensions of the package to be overpacked. 
         [0032]    The lid  30  is preferably provided with a plurality of castellations  210 , which project upwardly from the perimeter of the double-walled body  180  of the lid  30 . The castellations  210  are preferably arranged in a spaced relation around the perimeter of the lid  30 . Gaps  220  between the castellations  210  are preferably sized to accommodate a beam, such as a wood 2″×4″. Thus, an end portion of the beam can be received within a pair of gaps  220  aligned across a central axis of the lid  30 , leaving the remainder of the beam available for use as a lever to assist with threading the lid  30  onto the drum body  20 . It will be appreciated that the gaps  220  between the castellations  210  could be the same width (as illustrated) or could be of two or more two different widths such that at least a first pair of gaps  220  aligned across the central axis of the lid  30  will accommodate the wide dimension of a wood “2×4” (this dimension is typically about 3.5″) and at least a second pair of gaps  220  aligned across the central axis of the lid  30  will accommodate the narrow dimension of a standard “2×4” (this dimension is typically about 1.5″). 
         [0033]    To facilitate stacking of two or more sealed overpack salvage drums  10 , the castellations  210  and double-walled body  180  preferably define a recessed circular cavity for receiving the bottom end  230  of the drum body  20 . By reason of the double walled body  180  and “kiss-off” portions  200 , the lid  30  is sufficiently strong enough to accommodate a plurality of sealed, filled overpack salvage drums  10  stacked one on top of the other. 
         [0034]    If desired, a plurality of kiss-off portions  240 , which are shallower in depth than the kiss-off portions  200  provided in the double-walled body  180  of lid  30 , can be formed proximal to or within the gaps  220  between castellations  210  in order to provide additional strength in the area of the gaps  220  and castellations  210 . 
         [0035]    In some instances, particularly when the package to be overpacked is not entirely full and/or when the package to be overpacked contains a lightweight material, the drum body  20  will have a tendency to rotate or spin on the floor or pavement as the lid  30  is being threaded thereon. To prevent the drum body  20  from rotating while the lid  30  is being threaded thereon, the circular bottom wall  60  of the drum body  20  can be provided with one or more channels  250 , which cross the central axis of the circular bottom wall  60  of the drum body  20 . The channels  250  are preferably sized such that they can receive a beam such as a wooden “2×4”. A single channel  250 , or more preferably a plurality of channels  250 , are provided in the bottom wall  60 . An installer can stand on a beam received within a channel  250  to prevent the drum body  20  from rotating when the lid  30  is being threaded onto the drum body. Alternatively, the beam can be fixed to the floor. The drum body  20  can be placed onto the beam such that the beam is received in one of the channels  250 . The package to be overpacked can be placed into the drum body  20 , either before or after the drum body has been placed onto the beam. Once the lid  30  has been secured to the drum body  20 , the beam can be pulled from beneath the overpack salvage drum  10 , or the overpack salvage drum  10  can be pushed off the beam. 
         [0036]    The top side of the lid  30  is preferably provided with a plurality of blocks  260 , which are adapted to be received within the channels  250  formed in the bottom wall  60  of the drum body  20  when two or more overpack salvage drums  10  are stacked one atop another. The blocks  260  help maintain the alignment of the stacked overpack salvage drums  10  when stacked. 
         [0037]    With reference to  FIG. 5 , an annular groove  270  is formed on the underside of the double-walled body  180  of the lid  30 . The annular groove  270  extends completely around the lid  30  adjacent to the perimeter thereof. The annular groove  270  is adapted to receive a gasket  280 , which may be received within the annular groove  270  before the lid  30  is engaged with the drum body  20 . The gasket  280  is adapted to be sealingly compressed between the upper edge  150  of upper side wall portion  80  of the drum body when the raised thread  130  of the drum body  20  is mated with recessed thread  190  of lid  30 . 
         [0038]      FIGS. 9A-9C  show an alternative sealing arrangement. Instead of a gasket  280  being placed into an annular groove  270  in the lid  30  before the lid  30  is secured to the drum body  20 , a U-shaped gasket  290  can be secured to the upper edge  150  of the drum body  20  before the lid  30  is secured to the drum body  20  (Note: for ease of illustration only a portion of the U-shaped gasket  290  is shown in  FIG. 9A ; the U-shaped gasket  290  actually surrounds the entire upper edge  150  of the drum body  20 ). The upper edge  150  of the drum body  20  can be provided with a lateral edge  300 , which helps retain the U-shaped gasket  290  to the upper edge  150  of the drum body  20 . It will be appreciated that other sealing means, such as O-rings, for example, can be used in place of gaskets. It will also be appreciated that the gasket need no be U-shaped. Gaskets having a circular sectional profile, for example, can also be used. 
         [0039]    The annular skirt  170  terminates in a circumferential bottom edge  310 . When the lid  30  is completely threaded onto the drum body  20 , the circumferential bottom edge  310  is disposed near the upper shoulder  160  of the drum body  20 , but a gap or space remains therebetween. The annular skirt  170  has an outer diameter that is approximately equal to the outer diameter of intermediate side wall portion  90 . If desired, the gap or space between the circumferential bottom edge  310  and the upper shoulder  160  can be filled with optional curved filler strips (not shown) to prevent a handler of the overpack salvage drum  10  from attempting to lift the overpack salvage drum  10  by the lid  30  or from inserting the fork of a fork-lift or other tool between lid  30  and drum body  20 . As noted above, the overpack salvage drum  10  is adapted to be lifted from the lower annular shoulder  140  or the bottom wall  60 . 
         [0040]    As noted above, the overpack salvage drum  10  according to the invention further comprises at least one clip  40 , which is adapted to be operatively associated with the lid  30  before the lid  30  is threaded onto the drum body  20 . One clip  40  is typically sufficient, but two or more clips  40  can be used, if desired. The clip  40  is preferably made of a frangible material, so that it will break when sufficient force is applied to it. 
         [0041]    With reference to FIGS.  2  and  5 - 7 , the clip  40  preferably includes a head portion  320 , a tail portion  330 , a hook portion  340  and a body portion  350  that spans between the head portion  320  and the hook portion  340  and defines a channel for receiving a portion of the annular skirt  170  of the lid  30 . The head portion  320  includes an upper tip end  360  that is adapted to reside in a top recess  370  (see  FIG. 2 ) formed in the top side  380  of the lid  30 . The hook portion  340  includes a lower tip end  390  that is adapted to reside in a bottom recess  400  (see  FIG. 7 ) formed in an interior side of the annular skirt  170  of the lid adjacent to the bottom edge  310 . Before the lid  30  is threaded onto the drum body  20 , the annular skirt  170  of the lid  30  can be deformed slightly, allowing one to insert the lower tip end  390  of the hook portion  340  of the clip  40  into the bottom recess  400  and the upper tip end  360  of the clip  40  into the top recess  370  formed in the top side  380  of the lid  30 . Attaching the clip  40  to the bottom recess  400  first makes it more difficult to remove the clip  40  after the lid  30  has been secured to the drum body  20 . Once the clip  40  has been operatively associated with the lid  30  in this manner to form a lid  30  and clip  40  assembly, the annular skirt  170  springs back into shape and holds the clip  40  securely in place. Preferably, the portion of the annular skirt  170  of the lid  30  received in the channel defined by the body portion  350  between the head portion  320  and the hook portion  340  is recessed slightly such that the sides  410  of the recessed area can provide lateral support for the clip  40  as the lid  30  is threaded onto the drum body  20 . 
         [0042]    A threaded fastener  420  such as, for example, a security hex socket pin-head screw or a TORX® brand-type security pin-head screw, is also preferably employed to ensure that the clip  40  remains securely associated with the annular skirt  170  of the lid  30  during use. A first threaded insert  430  can be provided in the recessed area within the lid  30  for receiving the threaded portion of the fastener  420 . The first threaded insert  430  can be a molded-in insert, a self-tapping insert, an ultrasonically or thermally welded-in insert or the like. The fastener  420  is preferably used to secure the clip  40  to the lid  30  after the lid  30  has been threaded onto the drum body  20 . 
         [0043]    With reference to  FIG. 6 , the clip  40  is preferably secured to one of the blocks  260  in the lid  30  before the overpack salvage drum  10  is prepared for use. The clip  40  can be secured to the lid  30  using the same fastener  420  that is later threaded into the first insert  430  to secure the clip  40  to the annular skirt  170  of the lid  30 . A second threaded insert  440  can be mounted in the block  260  for receiving the threads of the fastener  420 . Furthermore, a fastener driver  450 , such as an Allen-wrench or other driver, can be operatively associated with the clip  40  (e.g., friction-fitted into holes in the clip) for removing and driving the fastener  420 . Thus, the clip  40  can be secured to the lid  30  during shipping and storage prior to use, but can easily be removed from the lid  30  using the fastener driver  450  and reattached to the annular skirt portion  170  of the lid  30  to ready the lid  30  for use. It will be appreciated that the fastener driver  450  need not be retained with the clip  40  during shipping and storage (e.g., it could be a separate item included in a package containing printed operating instructions). 
         [0044]    An outer portion of the intermediate side wall portion  90  of the drum body  20  is provided with a plurality of projections  460  proximal to the upper shoulder  160 . The plurality of projections  460  are preferably formed only on a portion of the circumference of the drum body  20 , as illustrated. At least one, and preferably all, of the plurality of projections  460  includes a camming surface  470 , which is adapted to contact and gently lift the tail portion  330  of the clip  40  over the projection  460  as the lid  30  is threaded onto the drum body  20  without fracturing the clip  40 . The camming surface  470  preferably has a smooth, arcuate surface profile. At least one, and preferably all, of the plurality of projections  460  also include a blocking surface  480  for contacting the tail portion  330  of the clip  40  and thereby prohibiting the lid  30  from being unthreaded from the drum body  20  after it has first been secured to the drum body  20 . 
         [0045]    Preferably, as the lid  30  and clip  40  assembly is threaded onto the drum body  20 , the tail portion  330  of the clip  40  passes (vertically) above the plurality of projections  460  during the first revolution of the lid  30  and then contacts the projections  460  as the lid  30  approaches the optimal point at which the gasket  280  is properly compressed between the upper edge  150  of the drum body  20  in the annular groove  270  in the lid  30 . At that time, the tail portion  330  of the clip  40  sequentially contacts the camming surface  470  of a first of a plurality of projections  460 , which lifts the tail portion  330  over the first of the plurality of projection  460 . This lifting and camming-over process is repeated until the lid  30  reaches the point at which the gasket  280  is optimally compressed to create a seal between the lid  30  and the drum body  20 . Indicia can be provided on the drum body  20  indicating the particular space or spaces between the plurality of projections  460  where the lid  30  is deemed to have been adequately secured to the drum body  20 . 
         [0046]    Once the lid  30  has been securely threaded onto the drum body  20 , the package contained within the drum body  20  is substantially permanently overpacked in the overpack salvage drum  10 . Throughout the instant specification and in the appended claims, the phrase “substantially permanent” means that the lid  30  cannot be removed from the drum body  20  without creating some evident damage to either the clip  40 , the lid  30  and/or the drum body  20 . In some instances, it may be desirable to establish a “substantially permanent” seal between the lid  30  and the drum body  20  for only a short period of time, such as when an overpacked package is being transported from one location to another. 
         [0047]    Once the lid  30  has been secured onto the drum body  20  in the manner thus described, the tail portion  330  of the clip  40  is retained in close proximity to the outer surface of the intermediate side wall portion  90  of the drum body  20 . The lid  30  cannot be unthreaded from the drum body  20  because the tail portion  330  of the clip  40  contacts against the blocking surface  480  of the last projection  460  the tail portion  330  cammed over when the lid  30  was initially threaded onto the drum body  20 . The blocking surface  480  does not lift the tail portion  330  of the clip  40  over the projection  460 , but rather it blocks the tail portion  330  of the lid  30  from rotating back past the projection  460 . It is not possible to remove the clip  40  from the lid  30  when the lid  30  is secured to the drum body  20 , because one would have to cant the tail portion  330  of the clip  40  inwardly and flex the annular skirt  170  in order to disengage the upper tip end  360  of the clip  40  from the top recess  370  formed in the lid  30 . This cannot be done because the intermediate side wall portion  90  of the drum body  20  prohibits inward movement of the tail portion  330  and the threaded engagement between the lid  30  and the drum body  20  prevents flexing of the annular skirt portion  170 . Thus, one must damage the lid  30 , the clip  40  and/or the drum body  20  in order to remove the lid  30  from the drum body  20  once the lid has first been secured thereto, which makes it evident that the integrity of the overpack salvage drum  10  has been compromised. 
         [0048]    As noted above, the clip  40  is preferably frangible, which means that it will preferentially fracture before damage occurs to the drum body  20  and/or the lid  30 . The frangibility of the clip  40  also makes it less likely that the clip  40  will penetrate the overpack salvage drum  10  in the event the overpack salvage drum  10  falls over or an external impact force is directed at the clip  40 . 
         [0049]    As noted, the present invention provides a method of overpacking a package using an overpack salvage drum  10 . First, a package to be overpacked is placed into the drum body  20 . This can be accomplished by lowering the package into an upright drum body  20 , by placing the package onto the bottom side  490  of the lid  30  and then placing the drum body  20  upside down onto the lid  30 , or more typically, by laying the drum body  20  onto its side and sliding the package therein and then standing the package-filled drum body  20  upright. 
         [0050]    A clip  40  is operatively associated with the lid  30  as described above to form a lid  30  and clip  40  assembly before the lid  30  is engaged with the drum body  20 . The lid  30  and clip  40  assembly is placed onto the drum body  20 , thereby forming a container that contains the package to be overpacked. The lid  30  is rotated until the raised threads  130  and the recessed threads  190  are properly indexed and engage with each other causing the lid  30  to thread onto the drum body  20 . As noted above, a beam can be placed into the gaps  220  between castellations  210  on the lid  30  and used as a lever to facilitate the threading of the lid  30  onto the drum body  20 , if necessary. And, a beam can be disposed in the channel  250  in the drum body  20  to prevent the drum body  20  from rotating as the lid  30  is being threaded thereon, if necessary. 
         [0051]    Before the lid  30  reaches the point at which it is optimally threaded onto the drum body  20 , the tail portion  330  of the clip  40  contacts the camming surface  470  of a projection  460 . The camming surface  470  of the projection  460  lifts the tail portion  330  of the clip  40  over the projection  460  without causing damage to the clip  40 . The lid  30  is tightened onto drum body  20  until the upper edge  150  of the drum body  20  compresses the gasket  280  in the annular groove  270 , thereby sealing the package within the overpack salvage drum  10 . At this point, the tail portion  330  of the clip is preferably retained in a gap between projections  460 , with the tail portion  330  abutting against the blocking surface  480  of the projection  460 . This prohibits the lid  30  from inadvertently unthreading from the drum body  20 . In order to remove the lid  30  from the drum body  20 , it is necessary to visibly damage the clip  40 , the lid  30  and/or the drum body  20 . The damage to the clip  40 , lid  30  and/or drum body  20  makes it readily evident that the initial integrity of the overpack salvage drum  10  has been compromised. 
         [0052]    As noted above, one of the features of the invention is that it allows for the establishment of a substantially permanent, tamper-evident seal between a lid and a drum body of an overpack salvage drum. This can be further enhanced by providing unique identification numbers or codes on the lid, clip and/or drum body. Thus, even if a damaged clip is replaced with a new clip, it will be possible to determine that the initial integrity of the overpack salvage drum has compromised. 
         [0053]    The lid and clip can also be shipped with an identification tag or label, which includes unique identifying indicia (e.g., serial numbers, bar codes etc.). The tag or label can be tucked beneath the clip when the clip is in the shipping position. The label or tag can be secured partially beneath the clip when the clip is operatively associated with the lid. The label or tag can include date fields that can be punched to indicate the date the package was sealed into the overpack salvage drum. Furthermore, the label or tag can identify the particular contents of the package. 
         [0054]    It will be appreciated that the clip could be formed integrally with the lid. However, the inventors believe that this is a less desirable arrangement. When it becomes necessary to remove a lid from an overpack salvage drum according to the invention, it is preferable for the clip to be damaged, but not the lid and/or the drum body. A new clip with a new identification number or code can be installed when the lid is placed back onto the drum body. If an integral lid and clip is used, the entire lid and clip assembly must be replaced. 
         [0055]    It will be appreciated that additional structures can be provided to further enhance the substantially permanent, tamper-evident seal between the lid and the drum body. For example, as shown in  FIG. 10 , a cable  500  can be drawn through the clip  40  and one or more eyelets  510  permanently associated with either the lid  30  and/or the drum body  20 . The eyelet(s)  510  can be permanently associated with the lid  30  and/or the drum body  20  using molded-in inserts, self-tapping inserts and/or by spin-welding techniques. A lock  520 , such as are commonly used to ensure that the initial integrity of the seal on utility meters, can be secured to the cable  500 . Furthermore, the fastener  420  can be provided with an opening through which the cable  500  can pass. Once the cable  500  is threaded through the opening in the fastener  420 , it is impossible to remove the fastener  420  without cutting the cable  500 . 
         [0056]    Preferably, the clip is provided in a color that is highly visible, yet contrasts with the color of the lid and drum body. For example, the lid and drum body could be formed of bright yellow polymer, with the clip being red. This allows for quick visual inspection to confirm that the clip has been properly installed onto and remains properly installed onto the overpack salvage drum. In one embodiment, a different color-coded clip is used to readily indicate the type of material contained within the overpack salvage drum. 
         [0057]    In another preferred embodiment of the invention, the overpack salvage drum  10  according to the invention further comprises an identification tag, which can be secured to the overpack salvage drum  10  using the fastener  420  that secures the clip  40  to the lid  30  after the lid  30  has been threaded onto the drum body  20 . The fastener  420  passes through an opening formed in the identification tag to keep the identification tag secured to the overpack salvage drum  10  until the fastener  420  is removed. The identification tag, fastener  420 , clip  40 , fastener driver  450  and any other material (e.g., instructions, warranty etc.) can be stored within a bag or pouch prior to use. 
         [0058]    The identification tag can include pre-printed information, which can be punched by an end-user as appropriate to provide information such as, for example, the composition of the package contained within the overpack salvage drum  10 , the date the package was contained within the overpack salvage drum  10  and/or the origin or location of the package contained within the overpack salvage drum  10 . Alternatively, indicia can be added to the identification tag to provide such information. The indicia can be handwritten, machine written (e.g. bar codes) or can be electronic in nature (e.g., an RF tag). Preferably, the identification tag is made of a durable, chemical resistant material such as a plastic film or a plastic-fiber textile material (e.g., DuPont&#39;s TYVEK® non-woven). 
         [0059]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.