Abstract:
An annular closure ring and bolt assembly for securing a lid or cover in sealed relation with an open-head drum is provided in which an annular split closure ring is closed by tightening a bolt between a pair of laterally spaced lugs attached to opposite ends of the closure ring. Each lug includes a hole to receive the bolt wherein at least one lug hole is unthreaded, and the bolt includes a shoulder or sleeve such that when the bolt is inserted into the unthreaded hole, the shoulder fits substantially flush with that unthreaded hole. The bolt engages either a threaded hole in one of the lugs or a jam nut to draw the lugs together and tighten the closure ring around the drum. The tight engagement between the unthreaded hole of the lug and the shoulder of the bolt thereby reduces movement of the bolt within the unthreaded hole to secure the connection of the ring around the open-head drum.

Description:
RELATED MATERIALS 
     The present application is a continuation-in-part application of pending U.S. patent application Ser. No. 09/356,915, filed Jul. 19, 1999, abandoned, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of storage containers and closure assemblies for securing storage container lids or covers to the open ends of storage containers, and, more specifically, the present invention relates to an improved closure ring assembly used to secure a drum lid to an open-head drum. 
     BACKGROUND OF THE INVENTION 
     Open-head drums are commonly used as containers for storage and transportation of bulk materials. These drums have a cylindrical opening to receive materials, and they conventionally include an annular closure ring assembly to secure a lid or similar covering around the cylindrical opening of the drum. To meet governmental regulations and industry standards, the closure ring assemblies of these drums must be able to withstand being tested by being dropped onto a rigid, non-resilient, smooth, flat and horizontal surface, where the point of impact is the most vulnerable part of the base of the intermediate bulk container being tested. Following the drop, the intermediate bulk container is examined to verify that the seal is maintained and that the contents are protected. Therefore, to meet these test requirements, a reliable closure ring assembly must be provided. 
     Failures with open-head drums frequently occur in the steel drum industry. Conventional open-head drums face hydrostatic leaks that occur when the drums are either improperly sealed or placed in heated areas where a build up of pressure can occur. Furthermore, conventional open-head drums also face drop failure due to improper sealing methods or by being accidentally dropped from a truck or rail shipment. To prevent hydrostatic and drop failure, several standards organizations developed hydrostatic and drop height limits. 
     A conventional closure ring assembly  10  is shown in FIGS. 1 and 2, which is similar to the closure ring assembly described in U.S. Pat. No. 5,584,410 issued to Siblik (“the Siblik patent”). This closure ring assembly  10  includes the following elements: a split closure ring  12  having two adjacent ends  22 ,  24 ; a first lug  16  having a unthreaded hole  17 ; a second lug  14  having an threaded hole  13 ; a conventional bolt  18  having a threaded cylindrical member  15  and a head  19  (shown in FIG.  3 ); and a jam nut  20 . A first lug  16  is attached to the first end  22  of the closure ring  12 , and a second lug  14  is attached to the second end  24  of the closure ring  12 . 
     To secure the lid to the opening of the drum, the closure ring  12  is placed around the lid and drum, and the threaded cylindrical member  15  of bolt  18  is inserted through the unthreaded hole  17  to engage the threaded hole  13 . As the threaded cylindrical member  15  engages the threaded hole  13 , the two ends  22 ,  24  of the closure ring  12  are drawn together to tighten the closure ring  12  around the lid and drum. 
     A common problem with the closure ring assembly  10  described above is the space  21  found between the bolt  18  and the unthreaded hole  17  (see FIG.  2 ). This space  21  allows undesired movement of the bolt  18  within the closure ring  12  when a force is applied to the drum, which allows movement of the closure ring  12 . For example, if the drum is dropped or rolled, the space  21  between the bolt  18  and the unthreaded lug  16  allows movement of the bolt  18  such that the lugs  14 ,  16  become unaligned and the connection between the bolt  18  and the threaded lug  14  is affected, which can disrupt the sealed relationship between the lid and the drum and cause the lid to become displaced from the drum. 
     To compensate for this problem, a jam nut  20  (shown in FIGS. 1 and 2) is used to secure the assembly  10 . The bolt  18  in this design is inserted through the unthreaded hole  17  and engages the threaded hole  13  to draw the two ends  22 ,  24  of the split closure ring  12  together around the open-head drum. The jam nut  20  is included in the assembly  10  to engage the threaded cylindrical member  15  and secure the lug  16  between the head  19  and the jam nut  20 , which aids the closure ring assembly  10  to withstand impact forces without moving the bolt  18  within the space  21 . However, a problem that arises with the use of the jam nut  20  is that the distance between the lugs  14 ,  16  is increased due to the location of the jam nut  20 , thereby loosening the connection of the closure ring  12  around the lid and drum. 
     Additionally, other designs have been provided to achieve a seal for an open-head drum that prevents against the leakage of the contents therein. For example, U.S. Pat. No. 3,907,349 to Kane (“the Kane patent”) describes an end closure ring assembly having an overlapping, light gauge ring that is used in an attempt to completely seal the drum. Light gauge rings as described in Kane conventionally have a width of approximately 0.052 inches. As a result, such rings are not able to securely attach lids as required by industry standards. Consequently, Kane further requires the ring to partially overlap to secure a lid to provide the most secure connection. Moreover, such a design requires epoxy or similar adhesive to keep from leaking. 
     What is needed, then, and not found in the prior art, is a closure ring assembly for open-head drums that will reduce the movement in the closure ring once the closure ring has been assembled on the drum and consequently provide a secure connection between the closure ring and the drum. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved closure ring assembly for use with open-head drums having a heavy gauge ring as required by industry standards that is able to secure a lid to the drum. 
     It is an object of the present invention to provide an improved closure ring assembly for use with open-head drums that overcomes the problem of undesired radial and axial movement of the closure ring. 
     It is another object of the present invention to provide an improved closure ring assembly for use with storage drums that eliminates the number of required elements between the lugs so that the closure ring may provide a tighter connection with the open-head drum. 
     These and other objects of the present invention are accomplished through an improved annular closure ring and bolt assembly used to secure a lid or cover to a conventional open-head drum. The annular closure ring is split to provide two adjacent ends that are capable of surrounding an open-head drum. Attached to the two ends are two lugs that have holes passing transversely through the lugs. A bolt is provided to intersect and engage the holes of the lugs to draw the lugs and the ends of the closure ring together around the lid and the drum. 
     More particularly, in the first embodiment of the invention, the first lug includes a purposely-large unthreaded hole that is necessary to eliminate cross threading and the second lug includes a threaded hole. The bolt is designed to pass through the large unthreaded hole to engage the threaded hole. To reduce unwanted movement between the large unthreaded lug and the bolt when the annular split ring is tightened around the lid and the drum, a shoulder is used with the bolt. The shoulder may be integrally formed onto the bolt, or it may be a slip sleeve or threaded sleeve that may be positioned by the head of the bolt. The diameter of the shoulder is designed to be slightly less than the diameter of the large unthreaded hole so that when the bolt engages the lugs, the shoulder is substantially flush with the periphery of the large unthreaded hole. The shoulder thereby reduces the movement that is allowable within the large unthreaded hole to secure the connection of the bolt to the lugs and reinforce the connection of the annular closure ring to the open-head drum. 
     Additionally, although not required, a jam nut may be included in this assembly to further secure the bolt to the lugs. The jam nut can engage the bolt between the lugs, as with conventional closure ring assemblies, to further secure the connection of the bolt. 
     In a second embodiment, both lugs include unthreaded holes. The bolt thereby passes through the unthreaded holes in the lugs to engage a jam nut which secures the bolt to the lugs. The shoulder of the bolt in this embodiment is extended so that it will be substantially flush with the periphery of the both holes when the closure ring is attached to the drum, which reduces the amount of movement allowable within the holes to secure the connection of the bolt to the lugs and to reinforce the connection of the annular closure ring to the open-head drum. 
     These and other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An annular closure ring and fastening assembly embodying the features of the present invention is depicted in the accompanying drawings which form a portion of this disclosure and wherein: 
     FIG. 1 is a top view of a split closure ring assembly of the prior art; 
     FIG. 2 is a partial sectional view of the closure ring assembly of FIG. 1; 
     FIG. 3 is a perspective view of the bolt of the closure ring assembly of FIG. 1; 
     FIG. 4 is an exploded perspective view of an open-head drum, lid, and closure ring assembly of the present invention; 
     FIG. 5A is a perspective view of a bolt used in one embodiment of the fastening assembly of the closure ring assembly of the present invention, with the bolt having a cylindrical shoulder rigidly affixed; 
     FIG. 5B is a perspective view of the bolt used in another embodiment of the fastening assembly of the closure ring assembly of the present invention, with a slip sleeve being affixed around a threaded cylindrical member of the bolt; 
     FIG. 5C is a perspective view of the bolt used in another embodiment of the fastening assembly of the closure ring assembly of the present invention, with a threaded sleeve being affixed around a threaded cylindrical member of the bolt; 
     FIG. 6 is a partial sectional view of a first embodiment of the closure ring assembly of the present invention having a lug with a threaded hole to receive the bolt and shoulder of the bolt; 
     FIG. 7 is a partial sectional view of the embodiment shown in FIG. 6 having an additional jam nut positioned between the lugs; and 
     FIG. 8 is a partial sectional view of a second embodiment of the closure ring assembly of the present invention having a pair of lugs with unthreaded holes to receive a bolt having an extended shoulder. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 4 and 6, an exploded view of the closure ring assembly  30  of the present invention is shown in conjunction with a lid  6  and open-head drum  8 . The preferred embodiment of the closure ring assembly  30  includes: a closure ring  32  that is split to provide adjacent ends  31 ,  33 ; a pair of lugs  34 ,  36  attached to the ends  31 ,  33  of the split closure ring  32 ; and a fastening assembly  37  for connecting the ends  31 ,  33  of the closure ring  32 . The fastening assembly  37  of the closure ring assembly  30  is included to limit undesired radial and axial movement. 
     Several embodiments of the fastening assembly  37  of closure ring assembly  30  are provided in the present invention, as illustrated in FIGS. 5A-5C. Looking to FIG. 5A, a first embodiment includes a bolt  38  having a head  42 , a threaded cylinder  44 , and an unthreaded cylindrical shoulder  40 , with the cylindrical shoulder  40  being connected to both the head  42  and the threaded cylinder  44 . In a second embodiment illustrated in FIG. 5B, the fastening assembly  37  includes a bolt  38  having a head  42  and a threaded cylinder  44 , that is used in conjunction with a slip sleeve  43  or similar disc through which the threaded cylinder  44  may pass. Furthermore, looking to FIG. 5C, an additional embodiment of the fastening assembly  37  is illustrated wherein a threaded sleeve  45  is able to be screwed onto the threaded cylinder  44  to provide the desired shoulder necessary for limiting axial and radial movement of the closure ring  32 . 
     Looking at FIG. 6, a sectional view of the first embodiment of the closure ring assembly  30  is shown. Accordingly, this closure ring assembly  30  serves to lock the lid  6  to the open-head drum  8 , and is able to withstand forces applied to the open-head drum  8  without displacement of the lid  6 . Each lug  34 ,  36  has a central cylindrical hole passing transversely therethrough, as indicated by  46 ,  48 . In the preferred embodiment, the first lug  36  of the closure ring assembly  30  has an unthreaded hole  46 , and the second lug  34  has a threaded hole  48 . The unthreaded hole  46  accommodates the passage of the threaded cylinder  44  of bolt  38  to engage the mating threads of the threaded hole  48  in the lug  34 . The two lugs  34 ,  36  are thereby drawn in proper alignment toward one another by the advancing rotation of the bolt  38  within the threaded hole  48 . This movement draws together the adjacent ends  31 ,  33  of the closure ring  32  to tighten the closure ring  32  about the drum cover. 
     As stated above, the diameter of the unthreaded hole  46  is chosen such that the threaded cylinder  44  of the bolt  38  can easily pass through the unthreaded hole  46 . Typically, the diameter of the threaded cylinder  44  is approximately 0.625 inches and the diameter of the unthreaded hole  46  is approximately 0.734 inches so that the threaded cylinder  44  has ample space to pass through the unthreaded hole  46 . Additionally, the unthreaded hole  46  is designed so that the fastening assembly  37  will be substantially flush with the unthreaded hole  46 . More specifically, the periphery of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  will be substantially flush with the unthreaded hole  46  when the bolt  38  is inserted into the lugs  34 ,  36 . Preferably, the difference between the diameters of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  and the unthreaded hole  46  will be no more than 0.01 inches. For example, the diameter of the cylindrical shoulder  40  of the preferred embodiment is approximately 0.724 inches. Consequently, the diameter of the unthreaded hole  46  is greater than 0.724 inches but ideally less than or equal to 0.734 inches. Due to the close interaction between the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  and the unthreaded hole  46 , there is little space for movement of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  within the unthreaded hole  46 . Consequently, the use of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  will reduce the displacement of the bolt  38  within the unthreaded lug  36  and reduce the opportunity of the closure ring  32  to loosen from the drum  8 . 
     This design provides advantages over prior designs in that the adjacent lugs  34 ,  36  are able to be welded closer to the ends  31 ,  33  of the closure ring  32  due to the absence of the jam nut  20  (see FIGS. 1 and 2) between the two lugs  34 ,  36 , and are therefore able to be drawn closer together. As a comparative example, in the conventional closure ring assemblies shown in FIGS. 1 and 2, the lugs  14 ,  16  are welded approximately 0.187 inches from the ends  22 ,  24  of the closure ring  12  because the jam nut  20 , having a width of approximately 0.375 inches, must have the space to fit between them. Further, when the conventional closure ring  12  is closed on a drum, the normal space between the ends  22 ,  24  of the closure ring  12  is approximately 0.250 inches. This means that conventional closure ring assemblies  10  require a distance of no less than 0.625 inches between the lugs  14 ,  16 . The lugs  34 ,  36  of the present invention, however, can be mounted on the closure ring  32  a distance of approximately 0.063 inches from the ends  31 ,  33  since there is no jam nut  20  between the lugs  34 ,  36 . Therefore, the distance between lugs  34 ,  36  is approximately 0.125 inches when the closure ring  32  is tightened around a drum  8 . Consequently, the present invention reduces this distance between the lugs  34 ,  36  of the closure ring  32  by approximately 0.500 inches from the conventional assembly  10 , resulting in a tighter connection between the closure ring  32  and the drum  8 . 
     Additionally, it should further be noted that the closure ring  32  of the present invention is a heavy gauge closure ring (preferably twelve gauge) that is conventionally used with open-head drums. Closure rings  32  that are heavy gauge have a thickness of approximately 0.095 inches, whereas light gauge closure rings (such as sixteen gauge) have a thickness of approximately 0.052 inches. Consequently, light gauge closure rings are more easily bent and maneuvered, but they are not capable of providing the strength that is necessary to secure lids onto open-head drums and to withstand the forces that are applied to open-head drums, especially during hydrostatic and drop testing of the drums. 
     The embodiment discussed above provides several advantages. First, the two lugs  34 ,  36  of the present invention are able to be drawn closer together due to the absence of the jam nut  20 , which betters the alignment between the lugs  34 ,  36  for improved performance compared to conventional assemblies. Second, the lugs  34 ,  36  may be welded close to the ends  31 ,  33  of the closure ring  32  to provide a tighter and improved seal around the drum  8 . In addition, the embodiment of FIG. 6 does not require additional parts (such as the jam nut  20  of FIG. 1) to form a secure connection for the ends of the annular split ring  32 , so it is more economical to build and maintain than conventional designs. 
     Looking at FIG. 7, the closure ring assembly  30  of the first embodiment is shown having an additional jam nut  50 . Although not necessary to maintain a secure connection in the closure ring assembly  30 , this jam nut  50  can be used to reinforce the connection of the bolt  38  with the closure ring  32 . Therefore, the jam nut  50  is placed between the lugs  34 ,  36  to provide contact with the second lug  34  between the jam nut  50  and the head  42  of the bolt  38 . 
     In a second embodiment shown in FIG. 8, the holes  46 ,  48  in both lugs  34 ,  36  are unthreaded. In this embodiment, the length of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  is extended so that the periphery of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  will be substantially flush with the holes  46 ,  48  of both lugs  34 ,  36  when the lugs  34 ,  36  are drawn together. In operation, the bolt  38  will initially engage the hole  46  in the first lug  36 , and then the hole  48  in the second lug  34 . A jam nut  50  is used to engage the bolt  38  after it passes through the hole  48  in the second lug  34 , and the interaction between the jam nut  50  and the bolt  38  will draw the ends  31 ,  33  of the closure ring  32  together. 
     As stated above, the periphery of the cylindrical shoulder  40 , the slip sleeve  43 , or the threaded sleeve  45  will be substantially flush with the hole  46  in the first lug  36 , and at least a portion of the periphery of the shoulder  40  will be substantially flush with the hole  48  in the second lug  34  once the lugs  34 ,  36  are drawn closer together. Consequently, the bolt  38  will thereby secure the closure ring assembly  30  to the open-head drum, and the extended cylindrical shoulder  40  (FIG.  5 A), slip sleeve  43  (FIG.  5 B), or threaded sleeve  45  (FIG. 5C) will help to prevent the undesired movement of the bolt  38  within the holes  46 ,  48  of both lugs  34 ,  36 . As a result, undesired movement of the closure ring assembly  30  will also be reduced. An additional benefit of this embodiment is that the closure seal ring  32  is easier to manufacture with two unthreaded holes  46 ,  48  as compared to other closure seal ring assemblies having lugs with threaded holes. 
     Thus, although there have been described particular embodiments of the present invention of a new and useful CLOSURE RING ASSEMBLY FOR AN OPEN-HEAD DRUM, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.