Patent Publication Number: US-2012031905-A1

Title: Container cap and seal assemblies

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/371,080 filed Aug. 5, 2010, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to container closures, and more particularly relates to container cap and seal assemblies for pastes, liquids and other materials. 
     BACKGROUND INFORMATION 
     Various types of container closures are known. For example, conventional solder paste jars have a base, a cap and a separate seal for minimizing air contact with the paste contained in the jar. Such seals are in the form of either a slidable piston that is pressed down in the base of the jar against the upper surface of the solder paste, or top seal installed in the region between the cap and the upper rim of the base. Although such standard seals may effectively prevent air from contacting the solder paste, they require additional steps during the manufacturing process in order to separately install the seal in the jar after the jar is filled but before the cap is secured to the base of the jar. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is to provide a container cap and seal assembly comprising a container base having an internal volume, a cap movable from an open position to a closed position on the container base, and a seal member having a sealing surface engagable with a surface of the container base to thereby provide a seal for the internal volume of the container base, wherein the seal member is temporarily held on the cap when the cap is initially moved from the open position to the closed position. 
     Another aspect of the present invention is to provide a cap and seal assembly for a container comprising a cap comprising at least one thread engagable with a base of the container, and a seal member held on the cap, wherein the cap and seal member are structured and arranged to temporarily hold the seal member on the cap until the cap is secured on the base of the container. 
     A further aspect of the present invention is to provide a method of sealing a container comprising at least partially filling a container base with a flowable material, and installing a cap and seal member together onto the container base, wherein the cap and seal member are structured and arranged to disengage from each other when the cap is subsequently removed from the container base. 
     These and other aspects of the present invention will be more apparent from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cutaway isometric view illustrating a container base, cap and seal arrangement in accordance with an embodiment of the present invention. 
         FIG. 2  is an exploded cutaway isometric view of the container assembly of  FIG. 1 . 
         FIG. 3  is a cutaway isometric view of the cap and seal arrangement of the solder paste container assembly of  FIG. 1 , illustrating how the cap and seal are attached together as a single unit when they are initially installed on the base of the container. 
         FIG. 4  is a cutaway isometric view of the seal secured on the base of the container with the cap removed, illustrating how the seal is disengaged from the cap when the cap is removed from the base of the container. 
         FIG. 5  is an isometric view of a container base in accordance with an embodiment of the present invention. 
         FIG. 6  is a side view of the container base of  FIG. 5 . 
         FIG. 7  is another side view of the container base of  FIG. 5 . 
         FIG. 8  is a cross sectional view taken through line  8 - 8  of  FIG. 7 . 
         FIG. 9  is a longitudinal sectional view taken through line  9 - 9  of  FIG. 7 . 
         FIG. 10  is an isometric view of a container cap in accordance with an embodiment of the present invention. 
         FIG. 11  is a sectional view of the container cap of  FIG. 10 . 
         FIG. 12  is an enlarged view of a portion of the container cap of  FIG. 11 . 
         FIG. 13  is a sectional view of a container seal in accordance with an embodiment of the present invention. 
         FIG. 14  is an enlarged view of a portion of the container seal of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIGS. 1-4 , a container assembly  10  in accordance with an embodiment of the present invention includes a container base  20 , a cap  30  and a seal member  40 . An additional piston seal  50  is shown installed in the base  20  of the container  10 . However, it is to be understood that the piston seal  50  may be optional when the seal member  40  is used. In certain embodiments of the invention, the container assembly  10  may be used to contain solder paste. However, it is to be understood that other types of pastes, liquids and flowable materials may be contained in the container assembly  10 . 
     As shown in  FIGS. 1-9 , the base  20  is generally cylindrical, with a rounded interior bottom portion  21  which facilitates removal of solder paste or other materials from the bottom of the container base  20 . A threaded closure  22  is provided at the upper edge  24  of the base  20 . An annular rim  25  surrounds the base  20 . Ridged stop members  26  are spaced 180 degrees around the outer circumference of the base  20  and extend radially outward from the base  20  adjacent to the annular rim  25 . In the embodiment shown, the threaded closure  22  is in the form of a quarter-turn closure which requires the cap to be turned only 90 degrees to close the container. However, any other suitable closure arrangement may be used, such as other threaded closures, snap-fit caps, etc. 
     As shown in  FIGS. 1-4  and  10 - 12 , the cap  30  includes quarter-turn threads  32  that engage the respective quarter-turn threads  22  of the base  20 . It is noted that the quarter-turn threads  32  may be replaced with any other threaded arrangement, as well as any other suitable closure arrangement such as a snap-fit cap as described above. The cap  30  includes a downwardly extending annular ring  34  with a beveled edge  35 . As more fully described below, the seal member  40  is temporarily held on the cap  30  through engagement with the ring  34 . Ridged stop members  36  are spaced 90 degrees around the inner circumference of the lid  30  and extend radially inward from the lid to engage the ridged stop members  26  of the base  20 . When the cap  30  is secured on the base  20 , two of the ridged stop members  36  engage the opposing ridged stop members  26  of the base  20  to provide tactile feedback when the cap  30  is hand-tightened. Although two ridged stop members  26  are shown on the base  20 , and four ridged stop members  36  are shown on the cap  30 , any other suitable number and shapes of tactile stop members may be used. 
     As shown in  FIGS. 1-4 ,  13  and  14 , the seal member  40  has a generally cylindrical sidewall  42  and an annular rim  43  that extends radially outward from the sidewall  42 . A lower surface of the annular rim  43  contacts the upper edge  24  of the base  20 . The generally cylindrical sidewall  42  is connected to a radially inwardly extending rim  44  with a circular flange  45 . In the embodiment shown, the inwardly extending rim  44  has a generally conical shape, however, any other suitable shape may be used. 
     At least a portion of the outer surface of the cylindrical sidewall  42  contacts the inner surface of the upper portion of the base  20  to form a seal therebetween, e.g., by means of an interference fit. At least one raised ring  46  extending a short radial distance outward from the outer surface of the cylindrical sidewall  42  may be used to provide the desired fit and sealing properties between the seal member  40  and the base  20 . In the embodiment shown, two such rings  46  are used, however, any other suitable number of rings may be provided. Thus, when the seal member  40  is installed on the base  20 , air is prevented from entering the interior of the base  20  due to contact between the outer surface of the sidewall  42  and the inner surface of the base  20 . Additional sealing may be provided by contact between the lower surface of the annular rim  43  and the upper edge  24  of the base  20 . 
     As shown in  FIGS. 1 ,  3  and  11 - 14 , the circular flange  45  of the seal member  40  has an inner surface that contacts an outer surface of the downwardly extending ring  34  of the cap  30 . In certain embodiments, at least one raised ring  48  extending radially inward from the inner surface of the flange  45  may be used to provide a desired fit between the seal member  40  and the annular ring  34  of the cap  30 . Contact between the inner edge of the circular flange  45  or the raised ring  48  and the outer diameter of the downwardly extending ring  34  retains the seal member  40  on the cap  30  when the cap  30  is initially installed on the base  20  during production. Thus, after the container base  20  has been filled with solder paste, a single operation is required to mount the seal member  40  and cap  30  together as a unit on the base  20 . In the embodiment shown, the downwardly extending ring  34  of the cap  30  is beveled  35  in order to facilitate initial mounting of the seal member  40  on the cap  30 . 
     The base  20 , cap  30  and seal member  40  may be made of any suitable materials such as polyethylene, polypropylene or the like. For example, the components may be made of polyethylene. In one embodiment, the base  20  and cap  30  are made of high density polyethylene, while the seal member  40  is made of low density polyethylene. If a piston seal  50  is used, it may be made of polyethylene, e.g., low density polyethylene. 
     In one embodiment, the dimensions of the rim  44 , flange  45  and raised ring  48 , as well as the dimensions of the downwardly extending ring  34 , are selected such that a slight interference fit or press fit is provided, e.g., a slight amount of outward radial deformation of the flange  45  and/or inward radial deformation of the ring  34  may occur when the seal member  40  is installed on the cap  30 . Such a fit or contact holds the seal member  40  in place on the cap  30  until the cap  30  is initially installed on the base  20 . Similarly, the dimensions of the outer diameter of the seal sidewall  42  or raised ring(s)  46  and the inner diameter of the base  20  are selected such that sufficient contact or interference fit is provided between the contact surfaces of the base  20  and seal member  40  in order to prevent air from entering the interior of the base  20 , while allowing the seal member  40  to be removed from the base  20  by hand without undue force. The degree of contact or interference fit between the respective parts may be selected by routine experimentation by those skilled in the art. 
     In accordance with an embodiment of the invention, the force necessary to remove the seal member  40  from the cap  30  due to the contact between the flange  45  and ring  34  is less than the force necessary to remove the seal member  40  from the base  20  due to contact between the outer surface of the seal sidewall  42  or raised ring(s)  46  and the inner surface of the base  20 . In this manner, during initial filling and production of the container assembly  10 , the cap  30  and seal member  40  may be installed on the base  20  as a single unit without the necessity of extra production steps conventionally required for separately installing seals and caps on standard containers. However, when the container assembly  10  is first opened by a user by removing the cap  30  from the base  20 , the seal member  40  disengages from the cap  30  and remains secured to the base  20  due to the contact between the sidewall  42  or raised ring(s)  46  of the cap and the inside of the base  20 . When the seal member  40  is subsequently removed from the base  20  by the user, it can optionally be pressed on to the cap  30  for convenience or safekeeping, in which case the seal member  40  will be automatically reinstalled on the base  20  when the cap  30  is secured to the base  20 . 
     In addition to allowing the cap  30  and seal member  40  to be installed on the base  20  together as a single unit during production, the radially inwardly extending rim  44  of the seal member  40  provides a finger grip for removal of the seal member  40  from the base  20 . Since the outer surface of the seal sidewall  42  or raised ring(s)  46  press against the inner surface of the base  20 , a certain amount of force is required to remove the seal member  40  from the base  20 , and the radially inwardly extending rim  44  provides a gripping surface to facilitate removal of the seal member  40  against such force. 
     For purposes of this detailed description, it is to be understood that the invention may assume various alternative variations except where expressly specified to the contrary. It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Such modifications are to be considered as included within the following claims unless the claims, by their language, expressly state otherwise. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.