Abstract:
A two piece clamping ring and lever system for retaining removable lids to containers comprises a split circular ring. The ring first end includes outwardly extending receiving hooks. The second end of the ring includes pivot bosses comprising a pivot shaft and enlarged button. A lever with pivot shafts engages with the ring first end. When the lever is closed contact surfaces on an inwardly projecting transverse beam on the underside of the lever and outwardly projecting beams on the ring first end engage to relieve stresses on the lever pivot shafts and ring first end pivot receiving hooks. A second stress transfer relationship is engaged as an inwardly facing transverse beam extending between the sidewalls of the ring second end is slideably engaged into corresponding receiving channels outwardly facing from the ring first end thereby relieving stresses on the pivot bosses and corresponding longitudinally extending lever bearing surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and is a continuation of U.S. patent application Ser. No. 12/455,114, filed May 28, 2009, which claims priority to U.S. provisional patent application No. 61/056,969, filed May 29, 2008, the disclosures of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to lidded container sealing systems and, more particularly, to a two piece polymeric clamping ring assembly for securing a lid to a container. 
       BACKGROUND 
       [0003]    A wide variety of materials are stored and or transported in lidded containers, where the lid is secured to the container with a clamping ring. A number of different container, lid, and damping ring configurations have been employed. 
         [0004]    Originally lids were secured on containers with clamping rings made of metal construction, having a generally U-shaped cross-section. However, these metal clamping rings are prone to corrode, or when painted the paint is prone to flake off, leaving particles of contamination within the container contents. 
         [0005]    Thereafter, clamping rings of a thermoplastic construction were designed for the clamping of lids on containers without the concern for particulate contamination to the container contents. U.S. Pat. No. 4,678,216 to Gregory (1987) discloses a three piece thermoplastic clamping ring having a U-shaped cross-section, a clamping link, and a pivotable clamping lever; however, these clamping rings were not cost competitive with metal clamping rings meeting similar container performance criteria. U.S. Pat. No. 5,129,537 to Bordner (1992) discloses a two piece polymer clamping ring designed for use in securing a lid to a fiber container; however, when this design was employed to secure plastic lids on plastic containers, excessive stress was imposed upon the pivot shaft or pin integrally formed upon the pivot arm of the clamping system which caused the system to fail. U.S. Pat. No. 5,713,482 to Bordner (1998) discloses a lower profile two piece polymer clamping ring designed to provide a more secure union between the container and the lid than the previous Bordner design when used on fiber or plastic containers; however, this clamping system having a similar design in the pivot shaft or pin integrally formed upon the pivot arm of the clamping system is prone to fail in a similar fashion as the previous design. 
         [0006]    Conventional designs include transverse molded pivot shafts on both the clamping ring and the pivot arm or lever. During the injection molding process these transverse molded pivot shafts are typically the last point where the polymer fills the mold. Because of the symmetrical nature of the clamping ring and lever, the polymer will fill the pivot shaft from both sides leaving a knit-line in the center of the pivot shaft. This knit-line is typically weaker than the surrounding polymer and may fracture under stresses induced as the lever is closed drawing the two ends of the clamping ring tight around the container and lid assembly, or fail as a result of stresses induced when the container is tipped or dropped. 
         [0007]    Another common feature of these designs includes a receiving notch integrally molded to the clamping ring that receives the transverse molded pivot shaft. The receiving notch is generally C shaped and is prone to opening up under stress thereby allowing the pivot arm to disengage and the system will fail to clamp the lid to the container with sufficient force. U.S. Pat. No. 5,713,482 to Bordner (1998) discloses a stress transfer relationship between the two ends of the ring designed to relieve excess stress from the pivot arm and receiving notch interface; however, these features do not sufficiently engage each other to provide the required stress transfer to eliminate the breakage of the pivot arm or bending of the receiving notch in similar stress environments to those described above. 
         [0008]    In one form of the conventional two piece polymer clamping ring assemblies, the pivot arm or lever has a cover portion extending over the receiving portion of the ring pivot shaft that is thermally or ultrasonically welded shut after assembly of the lever to the clamping ring. This feature is designed to secure the pivot shaft to the lever while allowing the two components to maintain a slideable relationship as the lever is opened and closed. The secondary plastic welding operation required to secure the two components together adds manufacturing cost to the assembly. 
         [0009]    The present invention is directed at solving one or more of the problems discussed above in a novel and simple manner. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention discloses a two piece polymer clamping ring and lever system for retaining removable lids to containers. While providing the advantages of polymer ring attributes to mitigate contamination seen in metal counterparts, the system is easy to assemble without the addition of secondary equipment such as welding required to securely retain the ring pivot shaft in the lever. 
         [0011]    In a preferred embodiment the polymeric clamping ring assembly is able to withstand greater stresses than conventional designs without breaking or yielding due to a combination of the nesting feature of the ring second end over the lever, the nesting of the lever over the first end of the ring, and the ability of the pivot bosses joining the second end of the ring to the lever to move independent of one another as the container is tipped over or dropped on the ring. The independent nature of the pivot bosses allows them to move with the container impact and return to their original shape without fracturing in a similar mode to the conventional transverse molded pivot shafts. 
         [0012]    Another feature of the invention is to provide a two piece polymer clamping ring and lever system for retaining removable lids to containers. The clamping ring comprises a split circular ring, having an inwardly opening generally U-shaped channel formed of polymeric material, having first and second ends, an outer circumferential wall and oppositely disposed inwardly facing sidewalls. The ring first end including a plurality of outwardly extending receiving hooks, a plurality of outwardly facing receiving channels, and a plurality of outwardly extending stress transfer beams. The ring has an oppositely disposed second end including a flared region with mutually inwardly facing internal surfaces slideably moveable in adjacency over the outwardly facing side surfaces of the lever. The inwardly facing sidewalls of the second end of the ring include an inwardly facing transverse beam extending between the sidewalls and inwardly extending pivot bosses comprising of a pivot shaft and enlarged button. A lever having an inwardly opening generally U-shaped channel form having mutually inwardly facing internal surfaces slideably moveable in adjacency over the side surfaces of the ring first end. The lever having a pivot end,formed with a plurality of pivot shafts inwardly extending from the spaced apart sides of the lever to a pivot beam longitudinally disposed about the center of the lever underside, and a plurality of ring pivot boss receiving windows projecting through oppositely disposed lever sidewalls having pivot boss access openings extending to pivot shaft bearing surfaces spaced from the lever pivot shafts a distance selected for drawing together the ring first and second ends. The lever having an inwardly extending transverse beam between the spaced apart sides rearward of the pivot boss access opening. The lever pivot shafts are configured for pivotable engagement with the ring first end receiving hooks and the lever receiving windows are configured for slideably receiving the ring second end pivot bosses. Movement of the lever from a generally radial position to a generally tangential position during closing of the lever constricts the ring trapping the lid and container flanges in the U-shaped split ring channel. 
         [0013]    It is another feature of the invention that the movement of the lever from a generally radial position to a generally tangential position during closing of the lever engages a first stress transfer feature between a transverse beam extending between spaced apart sidewalls of the lever underside and a plurality of outwardly facing beams on the first end of the ring. This feature transfers stresses from the lever pivot shafts and the corresponding ring first end receiving hooks. 
         [0014]    It is another feature of the invention that the movement of the lever from a generally radial position to a generally tangential position during closing of the lever engages a second stress transfer feature between a transverse beam extending between spaced apart sidewalls of the second end of the ring underside and a plurality of outwardly facing receiving channels on the first end of the ring. This feature transfers stresses from the ring second end pivot bosses and the corresponding lever receiving windows. 
         [0015]    Other objects of the present invention will in part be obvious and will in part appear hereinafter. 
         [0016]    The invention accordingly comprises the apparatus possessing the construction, combination of elements, and interrelationships that are exemplified in the following disclosure and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    A fuller understanding of the nature and objects of the present invention will become apparent upon consideration of the following detailed description, taken in connection with the accompanying drawings, wherein: 
         Drawings—Figures 
         [0018]      FIG. 1  is a perspective view of a container including a container, lid and clamping ring according to the invention; 
           [0019]      FIG. 2  is a top view of the container assembly of  FIG. 1 ; 
           [0020]      FIG. 3  is a partial sectional view taken through the plane  3 - 3  in  FIG. 2 ; 
           [0021]      FIG. 4  is a top view of the pivot end of the clamping ring component of the invention; 
           [0022]      FIG. 5  is a side view of the pivot end of the clamping ring component of  FIG. 4 ; 
           [0023]      FIG. 6  is an end view of the pivot end of the clamping ring component of  FIG. 4 ; 
           [0024]      FIG. 7  is a top view of the flared end of the clamping ring component of the invention; 
           [0025]      FIG. 8  is a sectional view taken through the plane  8 - 8  of  FIG. 7 ; 
           [0026]      FIG. 9  is an end view of the flared end of the clamping ring of  FIG. 7 ; 
           [0027]      FIG. 10  is a top view of the lever component of the invention; 
           [0028]      FIG. 11  is a side view of the lever of  FIG. 10 ; 
           [0029]      FIG. 12  is a bottom view of the lever of  FIG. 10 ; 
           [0030]      FIG. 13  is a partial side view of the two piece clamping ring and lever assembly of the invention showing an open orientation thereof; 
           [0031]      FIG. 14  is a partial side view of the clamping ring assembly of  FIG. 13  showing its orientation while being closed; 
           [0032]      FIG. 15  is a partial side view of the clamping ring assembly of  FIG. 13  showing its orientation while closed; 
           [0033]      FIG. 16  is a partial side view of the two piece clamping ring and lever assembly of e invention showing the lever thereof; 
           [0034]      FIG. 16A  is a partial side view of a second embodiment of e two piece clamping ring and lever assembly of e invention showing the lever thereof; 
           [0035]      FIG. 17  is a sectional view taken through the plane  17 - 17  in  FIG. 16 ; 
           [0036]      FIG. 17A  is a sectional view taken through the plane  17 A- 17 A in  FIG. 16A ; 
           [0037]      FIG. 18  is a sectional view taken through the plane  18 - 18  in  FIG. 16 ; 
           [0038]      FIG. 18A  is a sectional view taken through the plane  18 A- 18 A in  FIG. 16A ; and 
           [0039]      FIG. 19  is a sectional view taken through the plane  19 - 19  in  FIG. 16 . 
       
    
    
     DRAWINGS—REFERENCE NUMERALS  
       [0000]    
       
           20  two piece clamping ring assembly 
           22  U-shaped channel 
           24  ring first end pivot receiving hook—first 
           25  ring first end pivot receiving hook—second 
           26  ring second end (flared end) 
           28  ring lockpin lug—first 
           29  ring lockpin lug—second 
           30  lever pivot boss access opening—first 
           31  lever pivot boss access opening—second 
           32  pivot button—first 
           34  pivot boss shaft—first 
           36  lever pivot boss bearing surface—first 
           37  lever pivot boss bearing surface—second 
           38  first end of ring 
           40  lever pivot shaft—first 
           42  lever pivot shaft—second 
           43  pivot boss shaft—second 
           44  pivot button—second 
           46  container 
           48  lid 
           50  flexible gasket 
           52  annular lid rim 
           54  container upper contact surface 
           56  lid outer circumferential sidewall 
           58  container rim edge 
           60  container sidewall 
           62  Lever pivot boss—first 
           63  Lever pivot boss button—first 
           64  Lever pivot boss—second 
           65  Lever pivot boss button—second 
           66  ring second end sidewall—second 
           68  ring second end sidewall—first 
           70  ring lockpin lug aperture—first 
           72  ring lockpin lug aperture—second 
           76  ring pivot receiver opening—first 
           77  ring pivot receiver opening—second 
           78  lever sidewall—second 
           80  lever sidewall—first 
           82  ring object 
           84  lever object 
           86  lever pivot boss receiving window—first 
           88  lever pivot boss receiving window—second 
           90  lever lockpin aperture 
           92  container groove 
           94  ring inner circumferential wall 
           96  ring upper sidewall 
           98  ring lower sidewall 
           100  container rim side surface 
           102  container assembly 
           104  container assembly rim structure 
           106  lever pivot boss alignment—first 
           108  lever pivot boss alignment—second 
           110  lever longitudinal pivot beam 
           112  lever detent ribs—first 
           114  lever detent ribs—second 
           116  ring detent ribs—first 
           118  ring detent ribs—second 
           120  lever transverse stress transfer rib 
           122  ring stress transfer beam—first 
           124  ring stress transfer beam—second 
           126  ring transverse stress transfer beam 
           128  ring stress transfer receiving channel—first 
           130  ring stress transfer receiving channel—second 
           132  ring first end cutaway 
           134  ring second end cutaway 
       
     
       DETAILED DESCRIPTION 
       [0105]    In the illustrated embodiment of the invention, as shown in  FIGS. 1-3 , an assembly comprised of a polymer container, a lid and a polymer two piece clamping ring is revealed generally at  102 . The container  46  is of one piece blow molded construction configured such that the sidewalls slightly taper inwardly at the bottom and having an annular end portion defining a top opening. The upper portion of the container is configured having an integrally formed, outwardly disposed upper sidewall  60  which transitions to an inwardly extending engaging region or groove  92  having an upper contact surface  54  seen in the cross sectional view of the container assembly rim or chime structure shown in  FIG. 3 . Container  46  is depicted as being closed by a lid  48 , typically formed of a polyolefin material; and secured to the rim structure  54  of the container  46  by a two piece polymer clamping ring assembly represented generally at  20 .  FIG. 2  shows the top view of the container assembly represented generally at  102 . 
         [0106]    The rim structure of the container assembly  102  is shown in general at  104  in  FIG. 3 . Container  46  having an integrally formed, outwardly disposed upper sidewall  60  which transitions to an inwardly extending engaging region or groove  92  having an upper contact surface  54 . The container rim structure is further configured to define an upwardly extending side surface  100  which extends upwardly in a circumferential fashion to form an upwardly disposed rim edge  58 . The underside of the annular lid rim  52  captures a flexible gasket  50  and is seen to be nested over the container rim edge  58 . Flexible gasket  50  is made from a suitable rubber, polymer, or urethane material such that it compresses and seals the container assembly when sandwiched between the underside of the annular lid rim  52  and the upper edge of container rim edge  58 . 
         [0107]      FIGS. 1-3  depict certain elements of the two piece clamping ring assembly  20  which are discussed in detail later herein. The two piece clamping ring represented generally at  20  in the closed position, is comprised of a split circular ring  82 , having an inwardly opening generally U-shaped channel formed of polymeric material having first and second ends and including an outer circumferential wall  94 , two oppositely disposed inwardly facing sidewalls, the upper wall  96  and the lower wall  98 . Lever  84  is pivotably engaged to the ring  82  first end  38  and slideably engaged to the ring  82  second end  26 . Movement of the lever from a generally radial position to a generally tangential position during closing of the lever constricts the ring sidewall  94  against the lid skirt sidewall  56  while the ring lower sidewall  98  and upper sidewall  96  draw the container upper contact surface  54  and the lid rim  52  together to provide compression on flexible gasket  50 , 
         [0108]      FIGS. 4-6  illustrates the top, side and end views of ring  82  first end  38 . Ring first end  38  having a first outwardly extending pivot receiving hook  24  with a first receiving channel  128  and an outwardly extending stress transfer beam  122  rearwardly spaced from hook  24  leaving pivot receiver opening  76 . Ring first end  38  also having a second outwardly extending pivot receiving hook  25  with a second receiving channel  130  and an outwardly extending stress transfer beam  124  rearwardly spaced from hook  25  leaving pivot receiver opening  77 . A first outwardly extending lockpin lug  28  having lockpin lug aperture  70  and a second outwardly extending lockpin lug  29  having lockpin lug aperture  72  are shown in  FIG. 4 . A first pair of detent ribs  116  projecting outwardly from ring  82  sidewall  96  is shown in  FIG. 5 . A second pair of detent ribs  118  projects outwardly in similar fashion from ring  82  sidewall  98  as shown in  FIG. 4 . 
         [0109]      FIGS. 7-9  illustrates the top, side partial cross section, and end views of ring  82  second end  26 . Ring second end  26  includes a flared region with inwardly facing sidewalls, a first sidewall  68  having an inwardly extending boss comprising pivot boss shaft  43  and pivot button  44 . A similar boss comprising pivot shaft  34  and pivot button  32  extends inwardly from the ring second end  26  opposite sidewall  66  as shown in  FIG. 7 . As shown in partial cross section in  FIG. 8 , an inwardly facing transverse beam  126  extends between sidewall  66  and sidewall  68 . 
         [0110]      FIGS. 10-12  illustrate the top, side, and bottom views of lever  84  having an inward opening generally U-shaped channel form having opposing sidewalk, a first sidewall  80  and a second sidewall  78  slightly flared outward toward the lever bottom such that the inwardly facing internal surfaces are slideably moveable over the outer surfaces of ring  82  first end  38 . Sidewall  80  having an inwardly extending pivot shaft  40 , and sidewall  78  having an inwardly extending pivot shaft  42  which meet at an inwardly facing longitudinal pivot beam  110 . 
         [0111]      FIG. 11  depicts a keyhole shaped pivot boss receiving window  86  having pivot boss access opening  30  and a longitudinally extending pivot shaft bearing surface  36  projecting through sidewall  80 . Opening  30  is sized to pass the boss button  44  depicted in  FIG. 7  while the narrow slot portion  36  will pass boss shaft  43  but not the larger diameter of button  44 . An analogous keyhole shaped pivot boss receiving window  88  having pivot boss access opening  31  and a longitudinally extending pivot shaft bearing surface  37  projecting through sidewall  78  is shown in  FIG. 12 . 
         [0112]      FIG. 12  reveals an inwardly extending transverse beam  120  extending between the internal surfaces of sidewall  80  and sidewall  78 . The lever having a first inwardly extending pivot boss alignment rib  106  and a second inwardly extending pivot boss alignment rib  108 . The lever having a first inwardly extending pair of detent ribs  112  from sidewall  80  and a second inwardly extending pair of detent ribs  114  from sidewall  78 . 
         [0113]      FIGS. 13-15  illustrate the orientations of the two piece polymer clamping ring assembly depicted generally at  20  when manipulated from an open to a closed orientation.  FIG. 13  illustrates the orientation of the clamping ring assembly  20  as shown in the generally open orientation assumed during the procedure of installing it upon the container rim and lid interface of the container assembly  102 . Ring  82  having ends  132  and  134  extend and join with one another such that ring  82  depicted in  FIG. 13  is a single piece except for the break between ends  38  and  26 .  FIG. 13  shows lever pivot shaft  40  has been inserted through the ring first end  38  pivot receiver opening  76  and into the corresponding receiving hook  24 . It is noted that a second lever pivot shaft  42  is simultaneously inserted through pivot receiver opening  77  and into the corresponding receiving hook  25 . The diameter of receiving hooks  24  and  25  having a slightly smaller diameter than pivot shafts  40  and  42  will exhibit a resilient give as pivot shafts  40  and  42  are inserted, thus capturing lever pivot shafts  40  and  42  in pivotable engagement with the respective receiving hooks  24  and  25  on the ring first end  38 . 
         [0114]    Sidewall  68  of ring second end  26  has an inwardly extending boss comprising pivot boss shaft  43  and pivot button  44 . A similar boss comprising pivot shaft  34  and pivot button  32  extends inwardly from the ring second end  26  opposite sidewall  66  as shown in  FIG. 7 . Lever  84  is joined with ring  82  second end  26  by flexing the sidewalls  66  and  68  away from one another sufficiently to slide the pivot bosses along the lever sidewalls  78  and  80  until the buttons  32  and  44  can enter their respective access openings  31  and  30 . When the first and second pivot boss buttons are engaged in the corresponding access openings on the lever the ring  82  second end  26  sidewalls  66  and  68  will straighten thereby allowing the pivot boss shaft  34  and pivot boss shaft  43  to slideably engage the corresponding lever pivot boss bearing surfaces  37  and  36  respectively. 
         [0115]    Comparing  FIGS. 14 and 15 ,  FIG. 14  shows the lever extending from the ring in a generally radial direction. Movement of the lever from that position to a generally tangential direction as depicted in  FIG. 15  draws the ring ends  38  and  26  into an overlapping position with the flared end of the ring  26  spanning lever  84  and lever sidewall  78  and  80  spanning the ring first end  38 .  FIG. 15  shows the two piece polymer clamping ring  20  in a closed position and lever detent ribs  112  and  114  are now engaged frictionally with the respective ring detent ribs  116  and  118 , and lockpin lug  28  aperture  70  is shown in alignment with the corresponding lever lockpin aperture  90  such that a seal or lockpin device can be inserted into the closed lever to provide means of security for the container assembly. 
         [0116]      FIG. 16  depicts a partial top view of closed ring assembly  20  revealing the position of the ring second end  26  pivot bosses as assembled to the lever. A partial cross section illustrated in  FIG.17  details the internal geometry of ring assembly  20  in the closed position. The lever  84  transverse rib  120  is shown abutted to ring first end  38  stress transfer beam  124  which transfers stresses away from lever pivot pin  42  and ring first end receiving hook  25 . In similar fashion the inwardly extending stress transfer beam of ring second end  26  is engaged in the corresponding receiving channel  130  of the ring first end  38 , thereby relieving stress from the ring second end pivot bosses  34  and  43 . 
         [0117]      FIG. 18  depicts a cross-sectional view through the axis of the lever  84  pivot shafts  40  and  42 , looking generally in the tangential direction. Here the lever longitudinal pivot beam  110  can be seen centrally connecting pivot shafts  40  and  42 . Longitudinal pivot beam  110  provides significant strength characteristics to pivot shafts  40  and  42  by transferring the stresses imparted on the pivot shafts through the center of the lever. An additional benefit of longitudinal pivot beam  110  is to provide a flow channel to resin during the component molding process thereby ensuring that the pivot shafts do not contain a resin knit line as can happen with a transverse pivot shaft. 
         [0118]      FIG. 19  is a cross-sectional view through the axis of the ring second end  26  pivot bosses  34  and  43  again looking in a generally tangential direction. In this view lever  84  pivot boss alignment ribs  106  and  108  can be seen adjacent to their respective pivot boss button  44  and  32 . These alignment ribs  106  and  108  create a secondary capture region for each pivot button acting in slideable engagement with the flat surface of pivot buttons  44  and  32  thus preventing the pivot buttons from twisting outward under stress and pulling through the longitudinal pivot boss bearing surface when the ring is in tension. The independent slideable engagements between the ring pivot bosses and the lever are an important feature which allows the assembly to withstand stresses imparted during container tip over and drops. 
         [0119]      FIGS. 16A-18A  illustrate a portion of a two piece clamping ring in accordance with a second embodiment of the invention. For simplicity, elements that are the same as those in the embodiment of  FIGS. 1-19  are illustrated with the same reference numerals. Likewise for simplicity only the portion of the lever pivot mechanism is illustrated as the remainder of the two piece polymer clamping ring is identical in this embodiment. 
         [0120]      FIG. 18A  illustrates a cross-sectional view looking in a generally tangential direction through the axis of the pivot end lever  84  showing inwardly projecting pivot bosses  62  and  64  and their respective pivot buttons  63  and  65 . Pivot bosses  62  and  64  are configured for pivotal engagement with the ring first end  38  receiving hooks  24  and  25 .  FIG. 17A  depicts a cross-sectional view longitudinally through lever  84  and ring first end  38  and second end  26 , revealing the larger diameter of lever pivot boss button  65 . 
         [0121]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.