CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent

Application Serial No. 61/371,080 filed August 5, 2010, which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] 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

[0003] 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

[0004] 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.

[0005] 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.

[0006] 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.

[0007] These and other aspects of the present invention will be more apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a cutaway isometric view illustrating a container base, cap and seal arrangement in accordance with an embodiment of the present invention.

[0009] Fig. 2 is an exploded cutaway isometric view of the container assembly of Fig. 1.

[0010] 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.

[0011] 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.

[0012] Fig. 5 is an isometric view of a container base in accordance with an embodiment of the present invention.

[0013] Fig. 6 is a side view of the container base of Fig. 5.

[0014] Fig. 7 is another side view of the container base of Fig. 5.

[0015] Fig. 8 is a cross sectional view taken through line 8-8 of Fig. 7.

[0016] Fig. 9 is a longitudinal sectional view taken through line 9-9 of Fig. 7.

[0017] Fig. 10 is an isometric view of a container cap in accordance with an embodiment of the present invention.

[0018] Fig. 11 is a sectional view of the container cap of Fig. 10.

[0019] Fig. 12 is an enlarged view of a portion of the container cap of Fig. 11 [0020] Fig. 13 is a sectional view of a container seal in accordance with an embodiment of the present invention.

[0021] Fig. 14 is an enlarged view of a portion of the container seal of Fig. 13.

DETAILED DESCRIPTION

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.