1. Field of the Disclosure
The present disclosure is generally directed to drum-type storage containers and more particularly to a plastic split ring clamp or lock ring for securing a lid to such a container, the ring having a low profile yet strong 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 very strong and sturdy, but also quite 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 stacking and handling. Also, when containers employing plastic lids and plastic drums are subjected to drop tests, excessive stress was detected, for example, upon the lever pivot shaft or pin 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 has a relatively large cross section profile and a relatively large protruding lever.
In one aspect according to the teachings of the disclosure, a lock ring is disclosed for securing a lid to a drum-type container. The lock ring has a body with a discontinuous circular ring shape. The body has a first free end and a second free end, an annular wall, and two spaced apart flanges together defining a clamping channel facing radially inward. A lever has a grip section at one end and a pivot section at an opposite end. The pivot section is pivotally attached to the body near the first free end. The lever is pivotable between a closed position and an open position and has two walls spaced from one another and connected by a third wall. A lever end is adjacent the first free end of the body. The lever end is formed by the annular wall and by one flange of the two flanges continuing to the first free end and the other flange of the two flanges terminating short of the first free end. When the lever is in the closed position, the third wall of the lever lies adjacent the annular wall, the annular wall of the lever end is positioned between the two walls of the lever, the body is captured between the two walls of the lever along the grip section, and a portion of one wall of the two walls of the lever lies generally in the same plane as the other flange along the lever end of the body.
In one aspect of the disclosure, the portion of the one wall can be formed by a stepped down segment in a central section of the lever from the grip section to the central section.
In one aspect of the disclosure, the one wall of the lever can be aligned with and generally parallel to the other flange when the lever is in the closed position.
In one aspect of the disclosure, a clamping end can be provided on the second free end of the body. The clamping end can have a clamping bar that can be coupled to part of the lever.
In one aspect of the disclosure, the lock ring can include a clamping end on the second free end of the body. The clamping end can have two walls. One of the two walls of the clamping end can lie against the outside of the one wall on the stepped down segment when the clamping end is connected to the lever.
In one aspect of the disclosure, the lock ring can include a clamping end on the second free end of the body and the clamping end can have two spaced apart walls. One of the two walls on the clamping end can lie generally in the same plane as the one wall on the grip section of the lever.
In one aspect of the disclosure, the lock ring can include a pocket formed in the third wall of the lever and a clamping end on the second free end of the body. The clamping end can engage the pocket to indirectly connect the first and second free ends of the body.
In one aspect of the disclosure, the lock ring can include a clamping end on the second free end of the body. The clamping end can have a clamping bar between two walls of the clamping end. The clamping bar can engage a pocket on the lever.
In one aspect of the disclosure, the lock ring can include a clamping end on the second free end of the body. The clamping end can have a clamping bar and the clamping end and clamping bar can be integrally formed as a part of the body and from the same material as the body.
In one aspect of the disclosure, the lever can include a pocket on the third wall. The pocket can include two slots, one formed in each of the two walls of the lever and adjacent the third wall. A clamping bar of the second free end can seat in the two slots.
In one aspect of the disclosure, the lever can have a cover over a pocket in the third wall. The cover can be a flexible part of the third wall and can have an attached end and a detached end. The detached end can provide access for a clamping bar on the second free end to the pocket and to slots of the pocket.
In one aspect of the disclosure, the lever can include a pocket and the pocket can include two slots, one formed in each of the two walls of the lever and adjacent the third wall.
In one aspect of the disclosure, the lever can have a cover over a pocket in the third wall. The cover can be a flexible part of the third wall and can have an attached end and a detached end. The detached end can provide access to the pocket.
In one aspect of the disclosure, the lock ring can include a hook on the annular wall of the body and spaced from the first free end. The hook can have a catch. A pivot pin can be provided on the pivot end of the lever. The pivot pin can be detachably connectable to the catch of the hook.
In one aspect of the disclosure, the lock ring can have a hook that is integrally formed as a part of the annular wall and from the same material as the body and can have a pivot pin that is integrally formed as a part of the lever and from the same material as the lever. The pivot pin can be attached to the hook.
In one aspect of the disclosure, the lock ring can include an aperture in the lever end near the first free end of the body and a protrusion on an inside surface of the annular wall within a portion of the clamping channel near the second free end of the body. The protrusion can seat in the aperture when the second free end of the body is connected to the lever and the lever is in the closed position.
In one aspect of the disclosure, the annular wall and the two flanges of the body can form a generally C- or G-shaped structure in cross-section.
In one aspect of the disclosure, a lower flange of the two flanges of the body can have a lip formed on an innermost edge thereof. The lip can depend below the lower flange.
In one aspect of the disclosure, the lock ring can include a lock tab that protrudes from a portion of the annular wall and can have a lock hole formed through the lock tab. A pass-through opening can be formed in the two walls of the lever. When the lever is in the closed position, the lock tab can be positioned between the two walls of the lever and the lock hole can be aligned with the pass-through opening in the lever.
In one aspect of the disclosure, the body and the lever can be formed of molded plastic materials.
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 lock ring disclosed and described herein solves or improves 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. The disclosed lock ring has a relatively low profile band or ring body and clamping or lever portion when engaged and closed. However, the ring body and lever are still robust and sturdy for use with plastic drums and lids so as to help retain the shape of the drum and hold the seal between drum and lid during a drop test. The disclosed lock ring is configured so that the lever, when closed, nests within the vertical footprint of one end of the ring body to produce a lower profile lock ring compared to existing metal and plastic lock ring products. The lever, when closed, also lies very close to flush in a radial outward direction with an outward facing surface of one end of the ring body, thus reducing the degree that the lever portion of the lock ring protrudes radially outward. The disclosed lock ring and lever thus have a lower vertical and lesser radial profile, which improves handling and stacking capability of drums with secured lids. These and other objects, features, and advantages of the disclosed low profile lock ring may become apparent upon reading this disclosure.
Turning now to the drawings,
As shown in
With reference to
The lock ring 30 is for fixing or securing the lid 26 to a drum-type container, such as the plastic drum 22. Generally, the majority of the ring body 32 in this example has a C- or G-shape in cross section, as can be seen in
If desired, the upper and/or lower flanges and the rim and/or shoulder can be contoured so that the ring body 32 snaps onto the assembled drum and lid. However, in this example, the rim and top opening are merely captured in the clamping channel of the lock ring 30 when installed. The size of the clamping channel 66 can be sized so as to create a snug or interference fit with the spacing of the shoulder 38 and the bead 40 and rim 46 when installed.
As shown in
The second free end 72 of the body 32 at the split is configured to form a clamping end 79 of the lock ring 30. The clamping end 79 has an integrally molded clamping bar 80 that extends vertically or widthwise across the ring body 32 between upper and lower walls 82, 84. The clamping bar 80 can have a relatively robust or larger diameter element for sufficient strength to accommodate use with all-plastic drums. The walls 82, 84 are continuations of the upper and lower flanges 60, 62 at the second free end 72. The clamping bar 80 is exposed at the second free end 72 through an opening 86 in the ring body 32 adjacent the second free end 72. The annular wall 64 terminates at a distance from the free end 72 to form the opening 86, as shown in
As shown in
A lock tab 92 protrudes from the radially outward facing surface of the annular wall 64. The lock tab 92 is spaced circumferentially further from the first free end 70 than the hook 74. In this example, both the lock tab 92 and the hook 74 are on the lever end 88 portion of the annular wall 64 as shown in
As shown in
The lock ring body 32 can vary in configuration and construction from the example described herein. The size and dimensions of the lever end components and the clamping end components can be altered. Though the ring body and the aforementioned components are all formed as one integral piece of the same material, the ring body can be formed of one piece and one material and one or more of the lock tab, hook, protrusion, and clamping bar can be formed as separate pieces and be attached to the ring body. In another example, the entire lever end 88 and/or clamping end 79 can also be constructed as separate pieces that are attached to the ring body. However, the one-piece unitary construction of the ring body as disclosed herein can provide a lock ring that is easy to manufacture, ship, store, and stock, that requires little to no assembly, and that is relatively robust, strong, and sturdy.
With reference again to
The pivot section 102 of the lever 36 can have a pivot pin 110 that is integrally formed as a part of the lever. The pivot pin 110 extends between the upper and lower walls 106, 108 across the end of the pivot section 102. A clearance hole 112 is provided through the vertical wall 104 at the end of the pivot section 102 and exposes the pivot pin 110. The hook 74 is configured to fit through the clearance hole 112 as shown in
In this example, a central section 114 of the lever 36 has a flexible finger or cover 116 formed by part of the vertical wall 104. One end 115 of the cover 116 is detached from the lever 36 while the other end remains attached via a flexible connection or joint, such as a living hinge or the like. A slot 118 is formed along each of the upper and lower walls 106, 108 adjacent the cover 116. The detached end 115 and the slots 118 separate three sides of the cover 116 from the lever 36. The cover 116 can thus flex about the other attached end. A pocket 120 is defined beneath the cover in the lever 36 between the slots 118. The cover 116 generally lies over the pocket. Blind ends 122 of the slots 118 are adjacent the proximal or attached end of the cover 116. The blind ends 122 and the attached end of the cover 116 form a closed end of the pocket 120 closer to the pivot pin 110. The detached end 115 of the cover 116 defines an opening onto the pocket 120, accessible when the cover is flexed radially outward away from the lever 36. As shown in
To install the lock ring 30, the clamping channel 66 is mounted over the container bead 40 to secure the lid 26 in place as described above and shown in
As shown in
The pocket 120 creates a pass-through opening defined through the central section 114 of the lever 36 and across the slots 118, as shown in
In the closed and clamped configuration of
As shown in
The design of the lock ring 30 in this example lowers the overall profile height of the lock ring and provides a very low profile on the top side of the ring. This can make stacking of drums one on top of the other easier and can reduce inadvertent contact with the lever 36 while handling the drums. The lever 36 is also relatively low profile in a radial direction. The furthest radial outward point on the lock ring 30 in this example can be the cover 116. The height and radial depth of the lock ring in this example can be reduced by reconfiguring the lever and ring body.
In the closed and clamped position, the upper and lower walls 82, 84 of the clamping end 79 lie against the outside surfaces of the stepped down segment 140 and the lower wall 108 on the lever 36. Thus, the clamping end walls 82, 84 define the tallest profile height portions of the lock ring 30. These can be formed relatively thin and still provide sufficient strength under tension during use, particularly with the multiple connection points provided between the split ends of the lock ring 30 when closed and clamped. As shown in
As shown in
Both the ring body 32, within the clamping channel 66, and the lever 36, within the walls 104, 106, and 108 (see
As will be evident to those having ordinary skill in the art upon reading this disclosure, the specific configuration and construction of the lock ring 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 lock ring 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 the various disclosed features of the lock ring. The material can be a moldable plastic type material and the materials of the lever 36 and ring body 32 need not be the same.
The low profile lock ring disclosed herein is particularly useful for all-plastic type drums that have no steel chimes to help maintain the round shape of the base 24 and top opening at the upper end 28. Thus, the ring body can be constructed having a sturdy, substantially rigid form. When attached to the drum, the lock ring can add strength and rigidity to the drum structure, particularly around the top opening. The ring body can have a robust form based on wall thickness and material characteristics. By having the lower flange 62 of the ring body extend through the lever end 88 to the second free end 72 of the ring, the strength characteristics of the ring body can be substantial, even while lowering the profile by eliminating the upper flange 60 in the lever end. Thus, the lock ring can provide a mechanism to help retain the round shape of the drum top opening when closed and clamped onto the drum, particularly in the event of a sudden drop or other impact on the container assembly. The lock ring also can provide hoop strength, i.e., strength under tension, created by the robust construction of the lever and clamping components and the several connection points. The disclosed low profile lock ring can be designed with different ring flange, wall, and lever wall thicknesses, shapes, contours, and the like to produce the desired ring sturdiness. Thus, the lock ring can not only provide hoop strength, but can also be configured to increase the strength of the drum opening when the lid is attached to aid in holding the shape of the drum and lid during use.
The size and shape of the container assembly can vary as well. Thus, the size and shape of the lid and the lock ring can also vary to accommodate. The disclosed lock ring can be utilized on containers other than all-plastic type drums, if deemed to be suitable for a particular application.
When installed, a snap-on structure of the lock ring, lid, and drum, if provided, may help retain the lock ring on the assembled lid and container. The ring body can be configured to snap over a lid lip and container shoulder in other ways while still providing a force-fit or positive engagement between the ring body and the lid and drum. Thus, the configuration and construction of the ring body, drum top opening, and lid rim components can be varied from the example herein and yet function as intended.
The diameter of the ring body is sized so that it can readily fit around the circumference of the assembled lid and drum in the open configuration. When installed, and when the pivot pin is received in the hook, the user can begin to pivot the lever toward the closed position in the direction toward the ring body. This motion will draw the two ring body free ends together, reducing the circumference of the lock ring and securing the ring around the lid and container. Various parts, such as the pivot pin and hook, the clamping bar, slots, and pocket, and the lock tab and pass-through opening across the pocket, can be reversed on the parts, if desired and feasible, while the basic function of the lock ring is maintained.
The upper wall of the lever within the stepped down segment 140 nests into position where the upper flange 62 of the ring body 32 has been eliminated at the lever end 88. The wider grip section 100 of the lever 36 straddles over and captures the entire ring body 32 structure between the upper and lower walls 106, 108. Also, the upper and lower walls 82, 84 on the clamping end 79 fit over and cover the walls of the lever on the stepped down segment 140. As shown in
Although certain lock ring features, functionality, and components 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 Ser. No. 61/672,868 of the same title and filed on Jul. 18, 2012. The entire content of this prior filed provisional application is hereby incorporated herein by reference.
Number | Date | Country | |
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61672868 | Jul 2012 | US |