1. Field of the Disclosure
The present disclosure is generally directed to drum-type storage containers and more particularly to a split ring clamp or lock ring for securing a lid to such a container, the ring having an integral one-piece molded construction.
2. Description of Related Art
Cylindrical containers or drum containers are known in the art for holding and storing chemicals, industrial materials, and the like. These types of containers are typically large drum sizes and are often constructed of either a metal material such as steel or, particularly in North America, a fiber material. Fiber drums are formed having a metal chime around the top lip or top opening as well as around the closed bottom. In other regions, particularly in Europe and the Far East, such drum containers are often formed of non-metallic and non-fibrous materials, such as plastic materials. With the rapid globalization of commerce, it has become much more common that plastic material is used for fabricating these types of drums, as well as for fabricating their removable lids. In this regard, there are ecological and other advantages associated with use of plastic drums and lids, such as the material being recoverable or recyclable.
Each container of this type has a replaceable lid retained in position by a split ring clamp or lock ring in order to securely close the top opening. International standards are developing, which may supplant separate national standards to regulate the performance of these types of drums and lids. From a national standpoint, the United States Department of Transportation (DOT), Research and Special Programs Administration, has produced standards and specifications for drum performance. Standards also have been promulgated by the United Nations organization. DOT standards typically call for drop tests to make sure the drums won't leak when subjected to some abuse or trauma during use.
The drums to be tested are filled with dry, finely powdered material to a specific net weight. The drums are then closed with the lids and then clamped by the split ring or lock ring. Depending upon the standards involved, the containers are required to withstand a drop from varying heights and at various orientations onto a hard surface such as concrete. To pass such tests or meet the standards, the drums must recover from such drops without rupture or leakage. One international testing approach involves a similar drop test, except that the drums are filled with water instead of powdered materials. Such tests also include a seal test where the drums are filled with water and upended to determine the presence of a leak.
The lids that typically close these types of drums are formed from stamped metal or molded plastic. The lids are then secured onto the drums by the split ring clamps or lock rings. Such clamps or lock rings have a channel to capture a rim of the lid-to-drum interface. An over-center lever is generally used to draw the ends of the split ring clamp structure together. In the past, these lock rings or clamps were made of steel and were durable and sturdy, but heavy and expensive. However, for many packaging, transportation, and incinerator container applications, industrial users of such drum containers have sought to avoid metal components such as lids and lock rings or split ring clamping devices. The known metal devices do not burn, are prone to corrode, and can sometimes insert minute metallic contaminants with the material packaged within the containers.
Plastic lids have been successfully developed, such as is described in U.S. Pat. No. 4,718,571. For some period of time, the development of corresponding plastic clamping rings, which could remain competitive in terms of cost and clamping performance, eluded those in the art until a successful all-plastic polymeric two-piece split ring clamp was devised. Such a plastic clamp ring found success in conjunction with fiber type drums, and is described in U.S. Pat. No. 5,129,537.
The two-piece polymeric split ring clamp described in the above noted '537 patent has remained popular for use with fiber-based drums. However, its experimental application for clamping plastic lids on plastic drums demonstrated a need for a more secure union between drum and lid. Plastic drums and lids typically are less rigid or study than metal drums, fiber drums with steel chimes, and metal lids. Further, the plastic split ring clamp, while advantageously being formed of only two major parts, had exhibited a profile at its over-center pivot level that protruded outwardly a substantial amount from the side of the drum and lid to which it is secured. Such a large protruding ring portion can significantly hinder drum handling. Also, when containers employing plastic lids and plastic drums are subjected to drop tests, excessive stress was imposed, for example, upon the lever pivot shaft or pin that was integrally formed upon the pivot arm of the clamping system.
U.S. Pat. No. 5,713,482 disclosed a split ring clamp or lock ring that provided a degree of improved performance in these areas. However, the ring disclosed in the '482 patent still was made from two separate parts including the split ring and the over-center lever, as well as the parts to attach the lever to the ring. The two parts must be separately fabricated from two different molds and then assembled afterwards in a separate process. The pivot joint of the over-center lever is also still subjected to a large amount of stress when securing the lock ring or clamp onto a drum and lid assembly and after being secured.
A lock ring for securing a lid to a container is disclosed and described herein in accordance with the teachings of the present invention. The lock ring in one example has a ring shaped body with a first free end and a second free end. A clamping pin is exposed near the first free end and a lever is connected near the second free end and has a hook thereon configured to engage the clamping pin. The lever is pivotable between a closed position and an open position. The hook is configured to selectively engage the clamping pin and draw the first and second free ends closely adjacent one another with the lever moved to the closed position and capable of disengaging the clamping pin with the lever in the open position. The body, lever, and lock pin are integrally formed of a one-piece unitary structure and the lever is connected via a living hinge to the body.
In one example, the body, lever, and lock pin can be formed of the same material. The material can be any suitable plastic material, resin material, thermoplastic material, Nylon material, moldable composite material, or the like. The invention is not limited to any specific material. The material should however be flexible, resilient, relatively strong under tension, and capable of being molded into relatively complex shapes.
In one example, the body can have a generally C-shape in cross-section. The body can have an upper leg, a lower leg, a vertical leg connecting the upper and lower legs, and a radially inward facing channel defined within the upper, lower, and vertical legs configured to engage and receive portions of a container and lid assembly therein.
In one example, an upper leg of the body can have a downturned portion at an innermost edge thereof to snap over and onto a portion of a lid on a container.
In one example, a lower leg of the body can have a bead formed on an innermost edge thereof to nest under a rim of a container. The bead can have a rounded face thereon facing radially inward.
In one example, the second free end of the body can be sized to fit or nest within the first free end of the body when the lock ring is in a closed configuration and the lever is in the closed position.
In one example, the living hinge can be positioned adjacent a notch formed in the vertical leg of the body near the second free end.
In one example, the lock ring can have a lock tab protruding from a portion of the body and a tab hole formed through the tab. A lock opening can be formed in the lever and a lock hole can be formed through the lever. The lock tab can be positioned within the lock opening in the lever and the lock hole can align with the tab hole when the lever is in the closed position. A part of a lock can be received through the tab hole and lock hole to lock the lever in the closed position.
In one example, the lock ring can be formed of a molded plastic material. Again, the material can vary.
In one example, the lever can nest over the second free end of the body in the closed position and the second free end of the body can nest within the first free end of the body with the lock ring in a closed configuration.
In one example, the lock ring can include one or more bosses protruding from a part of the lock ring near the living hinge. One or more guide tracks can be formed in another part of the lock ring near the living hinge. Each of the one or more bosses can slide along a corresponding track of the one or more guide tracks when the lever is moved between the open and closed positions.
In one example, the lock ring can include two bosses, one each on a side of the body near the second free end. The lock ring can also include two guide tracks, one each on opposed sides of the lever. Each of the bosses can slide along a corresponding one of the tracks when the lever is moved between the open and closed positions.
In one example, the lock ring can include one or more bosses protruding from a part of the lock ring near the living hinge. One or more curved guide tracks can be formed in another part of the lock ring near the living hinge. Each of the one or more bosses can slide along a corresponding track of the one or more curved guide tracks when the lever is moved between the open and closed positions.
In one example, the lock ring can include one or more bosses protruding from a part of the lock ring near the living hinge. One or more guide tracks can be formed in another part of the lock ring near the living hinge. Each of the one or more bosses can slide along a corresponding track of the one or more guide tracks when the lever is moved between the open and closed positions. The one or more bosses and guide tracks can be covered and hidden by a portion of the lock ring with the lever in the closed position and the lock ring in a closed configuration.
In one example, the lock ring can include one or more bosses protruding from a part of the lock ring near the living hinge. One or more guide tracks can be formed in another part of the lock ring near the living hinge. Each of the one or more bosses can slide along a corresponding track of the one or more guide tracks when the lever is moved between the open and closed positions. Portions of the first free end of the body can move onto and cover and hide the one or more bosses and guide tracks with the lever in the closed position.
In one example, the lock ring can have one or more bosses and one or more guide slots that engage one another to de-stress or unload the living hinge when the lever is moved between the open and closed positions. In one example, the bosses can seat in a closed end of the respective guide tracks in the closed position.
In one example, the lock ring can have one or more bosses and one or more guide slots that engage one another to de-stress or unload the living hinge when the lever is moved between the open and closed positions. Portions of the first free end of the body can move onto and cover the one or more bosses and guide tracks with the lever in the closed position.
In one example according to the teachings of the present invention, a lock ring for securing a lid to a container can be reconfigurable between a locked and an unlocked configuration. The lock ring has a ring shaped body with a first end, a second end, and a split therebetween. A clamping pin is exposed near the first end and a lever is connected near the second end and has a hook thereon configured to engage the clamping pin. The lever is pivotable between a closed position and an open position. The hook is configured to selectively engage the clamping pin and draw the first and second ends closely adjacent one another with the lever moved to the closed position and capable of disengaging the clamping pin the lever in the open position. A guide track on one of the body and the lever. A boss is on the other of the body and the lever and is configured to seat in and move along the guide track as the lever is moved toward the closed position. The body, lever, clamping pin, guide track and boss are integrally formed as a one-piece unitary structure and the lever is connected via a living hinge to the body. The boss and guide track are arranged to redefine the lever pivot from the living hinge with the boss engaged with the guide track.
In one example, the lock ring can include a lock tab protruding from a portion of the body and have a tab hole formed through the tab. A lock opening can be formed in the lever and a lock hole can be formed through the lever. The lock tab can be positioned in the lock opening in the lever and the lock hole can align with the tab hole with the lever in the closed position.
In one example, portions of the first end of the body can move onto and cover and hide the one or more bosses and guide tracks with the lever in the closed position.
Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which:
The unitary lock rings disclosed and described herein solve or improve upon one or more of the above-noted and/or other problems and disadvantages with prior known lock rings, split ring clamps, and like clamping devices of this type. In one example, the disclosed unitary lock ring is molded as a one-piece, integral unit and is entirely formed of plastic. The disclosed lock rings require no sub-assembly, no separate, discrete molds, and no after-assembly. The construction of the disclosed lock rings also reduces or eliminates stress on the lever pivot joint once closed or clamped. The disclosed lock rings alter the stress points placed upon portions of the ring when it is closed or clamped during use. The disclosed lock rings also have a lower profile, which improves handling of drums having lids secured thereby. These and other objects, features, and advantages of the disclosed unitary lock ring may become apparent upon reading this disclosure.
Turning now to the drawings,
The size and shape of the container 22 can vary within the spirit and scope of the present invention. As noted above, the material from which the container 22 is made can also vary. Instead of the container being molded as a one-piece plastic structure, as in the present example, the container can instead be formed of multiple steel components that are welded together or otherwise suitably assembled, or can be made from a fiber material with a steel bottom, a steel chime around the top opening, and a steel chime around the bottom, if desired. The disclosed unitary lock rings of the present invention can be utilized on containers other than the specific container 22 disclosed and described in this example. The shape and configuration of the container rim 34 can also vary from the example described herein and yet perform as intended. The below described lock ring 30 can be altered to accommodate different sized and shaped rim features.
The lid 24 in this example has a top panel 50 that is generally disc shaped and sized to cover the top opening 26 of the container 22. The top panel 50 has a stepped surface 52 around its perimeter that is contoured upward relative to the adjacent portion of the top panel. The stepped surface 52 is connected to an annular lid rim 54 defining the outer periphery of the lid 24. As shown in
In this example, an optional gasket or seal 64 is provided against the inside surface of the lip 60 in the downward facing channel 62. The seal or gasket 64 can bear against the top edge 42 of the container rim 34 and help to create a tight seal between the lid 24 and container 22 when assembled. The optional gasket or seal 64, as well as the overall shape of the top panel 50 and the lid rim 54 can also vary in configuration and construction within the spirit and scope of the present invention and yet function as intended. Similar to the container 22, the lid 24 can be fabricated as a one-piece unitary structure from plastic or can be fabricated from metal or other suitable materials, depending on the application or use intended. The material used to fabricate the optional gasket or steel 64 can also vary, but in one example can be a compressible and resilient silicone or rubber material.
The lock ring 30 has a unitary, molded plastic, one-piece structure in accordance with the teachings of the present invention. The lock ring 30 requires no assembly after fabrication, is lightweight, and requires only a single mold cavity to form. Multiple components do not need to be separately formed and then assembled to one another. With reference to
In the disclosed example, the body 70 of the unitary lock ring 30 has a somewhat C-like shape when viewed in cross section, as in
A ring channel 84 is formed by a combination of the upper leg 78, the vertical leg 82, and the lower leg 80 and faces radially inward. The ring channel 84 is sized to forcibly or interferingly receive therein and snap onto the assembled combination of the lid and container rims 54, 34. In the disclosed example, the upper leg 78 has a downturned portion 86 near its innermost edge. The downturned portion 86 is angled downward relative to horizontal or relative to a plane of the remainder of the upper leg 78. The lower leg 80 has a bead 88 adjacent its innermost edge. The bead 88 defines a rounded face 90 at the transition from the top surface and inward facing surface of the lower leg. The lower leg 80 can also be slightly angled downward in a direction toward the bead 88. The rounded face 90 and angle of the lower leg 80 can aid in attaching the lock ring 30.
When the lock ring 30 is not attached to the assembled lid 24 and container 22, a gap is defined between the downturned portion 86 and the lower leg 80 to permit entry into the channel 84. This gap is smaller than the distance between the assembled combination of the lip 60 on the lid rim 54 and shoulder 38 on the container rim 34. To install the ring body 70, the body 70 can be forced onto the assembled lid and container rims 54, 34. The gap into the channel 84 will be forcibly expanded, forcing the upper and lower legs apart. The body 70 can be zipped onto the assembled lid and container from one end to the other until the upper leg 78 snaps completely over the lip 60. As shown in
When installed, the snap-on structure of the rims 54, 34 and legs 78, 80 will retain the lock ring 30 on the assembled lid 24 and container 22. The ring body 30 can be configured to snap over the lid lip and container shoulder in other ways while still providing a force-fit or positive engagement between the body 70 and lid and container. Thus, the configuration and construction of these components can be varied from the example herein and yet function as intended.
The lever 76 in this example has an elongate grip section 104 that can be easily grasped by a user and provide mechanical advantage to clamp the lock ring 30 closed. The grip section 104 is also U- or C-shaped and has an upper wall 106, a lower wall 108 spaced from the upper wall, and an intermediate wall 110 connecting the upper and lower walls. The lower wall 108 can have a truncated free edge 112, different from a free edge 114 of the upper wall 106. The truncated free edge 112 can be provided to accommodate or provide clearance for the bead 88 on the lower leg 80 of the body 70 when the lever 76 is clamped or closed. The proximal end of the lever 76, and specifically the intermediate wall 110, continues integrally into the living hinge 77. The living hinge 77 in turn continues into and joins with the vertical leg 82 of the body 70. A notch 116 is formed in the body 70 across the vertical leg 82 and into the upper and lower legs 78, 80 around the living hinge 77 for mold clearance and for permitting freedom of movement of the hinge material. A pin hook 120 or engagement groove is formed across the lever 76 in the intermediate wall 110 and near the living hinge 77. As shown in
In this example, curved guide tracks or slots 122, 124 are respectively formed in each of the upper and lower walls 106, 108 on the lever 76. The guide tracks 122, 124 open into the distal end of the lever 76 in their respective walls. The curvature of the guide tracks 122, 124 essentially follows the pivotal movement of the lever 76 between the open and closed positions. Thus, the guide tracks or slots 122, 124 are positioned and shaped to create a path at a relatively constant radial distance from the pivot point of the lever 76 created by the living hinge 77. A lug or boss 126, 128 respectively protrudes integrally from each of the upper and lower legs of the body 70. The lugs or bosses 126, 128 protrude from the outer surfaces of the legs 78, 80 away from the channel 84 and opposite one another. Each boss 126, 128 is sized and shaped to be received in and slide along its corresponding guide track 122, 124. In this example, the bosses 126, 128 have a width and a curved shape that closely correspond with the width and curvature of the guide tracks or slots 122, 124. As described below, the bosses and guide tracks alleviate the stresses on the living hinge when the lock ring 30 is clamped onto a container.
The diameter of the ring body 70 is sized so that it can readily fit around the circumference of the assembled lid 24 and container 22. When installed as described above and when the pin hook 120 is connected to the clamping pin 100, the user can begin to pivot the lever 76 in a direction toward the second and 74 of the body 70. This motion will begin to draw the first end 72 of the body 30 toward the second end 74, as shown in
The lever 76 will then continue pivoting downward toward the second end 74 of the body 70 has depicted in
At least one or both of the upper or lower walls, in this case the upper wall 106, of the lever 76 can have a curved contact or bearing rib 130. The rib 130 can be positioned near but spaced from the forward or proximal edge of the wall and can be located and configured to nest or seat against a surface of the one end 72 on the ring body 70. The inner surfaces of the upper and lower legs 78, 80 on the first end 72 can bear against the outer surfaces of the lever upper and lower walls 106, 108 adjacent the rib or ribs 130. The rib or ribs 130 can also be provided to add structural rigidity and integrity to the lever 76. Also, the spacing between the upper and lower legs 78, 80 at the first end 72 can be such that the second end 74 nests or seats between the legs in the first end. The other of the upper or lower walls 106, 108 on the lever 76 can also include such a rib 130, or at least a partial rib. The ribs can be configured to help position and guide the two ends 72, 74 of the body 70 together when the lock ring 30 is clamped or closed and to positionally fix the two ends relative to one another once closed or clamped. Also, the upper and lower legs 78, 80 on the first end are spaced such that they cover the bosses 126, 128 and guide tracks 122, 124 as shown in
As shown in
With reference to
As will be evident to those having ordinary skill in the art upon reading this disclosure, the specific configuration and construction of the unitary lock ring 30 disclosed and described herein can vary from the example shown. Positional relationships, sizes, shapes, surface contours, and the like can vary and yet function as intended. Features of the unitary lock ring 30 can also be added or removed, as well as altered, without departing from the spirit and scope of the present invention. In addition, the material used to form the unitary lock ring disclosed and described herein can vary considerably as well. However, the material should be suitable to allow for formation of a living hinge sufficient to permit the lever to move relative to the ring body between the open and closed configurations.
The bosses can be provided on the lever and the guide tracks can be provided on the second end of the body, if desired. Similarly, the first end of the body can be configured to nest with the second end in the closed configuration of the ring. The guide tracks may include only a single track and the bosses may include only a single boss. More than two of each could also be provided. The secondary lock tab feature can also include two or more tabs for receiving two or more locks, if desired.
The one-piece unitary structure made of plastic is highly advantageous and a significant improvement over existing metal and plastic lock rings of this type. The cost is significantly reduced. The size and weight is also less than conventional rings of this type. The amount of bulk resin material usage is also reduced. The disclosed lock ring can be exceptionally strong and yet be made having relatively thin wall thickness in much of the ring. The multiple load bearing elements of the structure can distribute forces exerted upon the lock ring to multiple points along the ring and the joint at the split. The complexity of the mold cavity requirements is also reduced because only a single cavity is required to make the entire lock ring component.
Although certain lock rings for drum lids and features for such lock rings have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the disclosure that fairly fall within the scope of permissible equivalents.
This patent is related to and claims priority benefit of U.S. provisional application 61/506,619 filed on Jul. 11, 2011 and entitled “Unitary Lock Ring.” The entire content of this prior filed application is hereby incorporated herein by reference.
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