Container cap assembly
A container cap assembly comprises an annular cap body hinged to a lid. The cap body has a lower section with internal female threads for cooperation with matching male threads on a container and an annular upwardly extending flange. The lid has a downwardly extending flange. The flanges have interlocking sealing surfaces which extend outwardly at an acute angle to the vertical so that the lid flange will snap over the cap body flange in the closing mode and retain the lid in a closed and sealed position relative to the cap body until the lid is forced upwardly.
This application is a continuation-in-part of application Ser. No. 10/652,744 filed Aug. 29, 2003 entitled Container Cap Assembly.
FIELD OF THE INVENTIONThe present invention relates to a hinged cap assembly for capping containers and particularly to large mouth containers where a liquid tight seal is desired.
DESCRIPTION OF THE PRIOR ARTThere are many known varieties and shapes of container caps including bottle-type caps that have been and are presently in use. The known caps differ in configuration and arrangement int hat some are formed as just single cap members having cooperative sizes to conform to the sizes of the containers or bottles. Some are defined as simple snap-on caps and others are provided with internal threads arranged to match the threaded arrangements of particular designed containers.
Conventional snap-lid type of caps inherently do not provide a positive seal to establish a long shelf life for liquids or edibles stored therein. The caps are commonly formed from plastic materials and are snapped onto the container mouth. Such bottle caps as these are generally not provided with any type of sealing means such as gaskets.
Threaded lids generally include gaskets, but are not handy to use, especially for large mouth containers.
Containers and lids for storing foodstuffs and the like are generally made of a plastic material such as polypropylene or polyethylene polymers or copolymers. Such containers and lids are normally fairly rigid, but may be subject to some amount of flexure especially where the lid or cover is arranged to be peeled off of the container mouth. Most such container/lid configurations provide a sealing bead or rim along the upper wall of the container with a mating channel on the lid which engages the bead as well as the adjacent inner and outer surfaces of the container wall. Such sealing arrangements generally require considerable effort to force the lid onto the sealing bead during the closing procedure and perhaps greater effort to peal the lid away from the container during the opening process. While some lids are provided with one or more outwardly extending tabs to accommodate a user's fingers, the opening procedure may be quite difficult for a person suffering from arthritis or tendinitis. In addition, the lids of such sealable containers often become misplaced making lid replacement difficult or impossible. See U.S. Pat. No. 4,765,506.
In some designs a separate sealing member such as an o-ring or annular gasket is disposed between the container rim and the lid channel to provide a more secure seal. Such designs may rely on frictional forces to maintain the lid in place on the container or may rely on one or more latching arms carried by the lid which engage retention lips on the container or nut threaded onto the container. In either case the separate sealing member, i.e., o-ring or gasket involves not only added manufacturing costs, but is subject to being misplaced or lost during use of the container. See U.S. Pat. No. 5,582,314, issued to the assignee of this application.
In addition there are closures for small mouth containers in which a lid is connected to the cap body via a living hinge. The lid is formed with an inner circular slot which is arranged to snap over an upwardly extending annular flange on the cap body in the closed position. See the digital photograph of one such closure included in the information disclosure statement. It is not believed that the closure would provide a satisfactory seal if adapted to close large mouth containers and would not be easy to open for persons suffering from arthritis or tendinitis.
There is a need for a two-piece hingeable cap assembly for large mouth containers which is simple, relatively inexpensive to manufacture, substantially leak proof and easy to open and close.
SUMMARY OF THE INVENTIONThe present invention comprises a container cover or lid member hingeably mounted to a cap body that is internally threaded so as to be readily secured to any compatible threaded neck portion of a container. The cap body has a lower section with an inner threaded wall, an outer wall forming a generally inwardly extending shelf joined to an upwardly extending flange defining an annular exterior sealing surface which tapers outwardly at an angle θ with respect to the vertical and terminates in a free edge.
The lid member has a top surface and a bottom surface, a peripheral rim or skirt and a downwardly extending flange spaced inwardly from the skirt and defining an interior sealing surface which tapers inwardly at an angle λ with respect to the vertical. The lid flange is arranged to snap over the cap body flange to secure the lid member in a closed position when the lid member is pressed downwardly with the sealing surfaces forming an interference fit along a narrow ring circumscribing the contact between the sealing surfaces to provide a liquid tight seal between the lid and cap body. Preferably λ≠θ. The angle λ is preferably greater than X with the difference between the angles being preferably with the range of about 2° to 8° depending upon the diameter of the container mouth.
In a preferred embodiment the cap body and lid member are molded as a single piece connected together by a living hinge.
It is an object of the present invention to provide an inexpensive, reliable and substantially leak proof hingeable container cap assembly which does not rely on a separate gasket or o-ring to provide the seal or a separate latch arrangement to lock the lid to the cap body in the closed position.
It is a further object of this invention to provide a hingeable lid/cap body for large mouth containers which is easily opened by those suffering from arthritis or tendinitis problems.
The construction and operation of the container cap assembly of the present invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring more particularly to
A container cap assembly, generally designated at 12, is shown mounted on the container 10 and is formed from a suitable rigid or semirigid thermoplastic material of, for example, the polyolifin group, such as high density polyethylene, more preferably from a polypropylene that provides some flexibility and memory. Polypropylene is believed to be the least expensive of most commonly used plastics for molding many consumer products and thus advantageous from the cost standpoint. The container 10 is illustrated as a large mouth container, for example, having a standard diameter of 53 mm, 63 mm, 89 mm, 110 mm or 120 mm.
Referring now to the remaining figures, the container cap assembly 12 comprises a one piece annular cap body or nut 14 formed with a lower and upper section 16, 18, respectively, and a one piece lid member 20. The lower cap body section is formed with threads 16b on the interior surface 16a thereof. See
The upper section 18 of the cap body is in the form of an upwardly extending flange joined to the lower section via a rib section 19 (
The flange 18 defines an inner sealing surface 18c which extends downwardly from the exterior corner 18d of the rim at an angle of θ degrees with respect to the vertical. A rounded corner 18e is formed between the lower end of the sealing surface and the web section as is shown more particularly in
The lid member 20 has a slightly convex shaped top surface 20a, a bottom surface 20b of matching curvature and a peripheral rim 20c, (
The sealing surface 22a of the lid flange is oriented at an angle of λ to the vertical in the unstressed condition of the flange, i.e., when the lid is in the open position and positioned horizontally. See
A downwardly extending hinge plate 20e is formed integrally with the lid peripheral rim and carries at it's lower end a pair of outwardly projecting axle stubs 20f. During assembly of the lid and cap body, the axle stubs are forced into the semicylindrical bores 16f at the end of the slots 16e in the cap body. See
A downwardly extending tongue 20h is positioned diametrically opposite the hinge and is formed integrally with the lid peripheral rim. The tongue 20h includes, at its lower end, an outwardly extending finger engaging member 20i.
During the closing mode, the lid member is pushed downwardly against the cap body and container causing the rounded end 22b of the sealing flange to engage the corner 18d of the cap body flange and flex outwardly a slight amount allowing the lid flange to continue to move downwardly along the tapered sealing surface of the cap body flange. The resilience of the material causes the lid flange to flex against the tapered cap body sealing surface and releasably lock the lid to the cap body in the position shown in
The force exerted between the flange sealing surfaces along this line contact forms a substantially liquid tight seal preventing the contents in the container from spilling. It is to be noted that in the event that a filled container is turned upside down the pressure on the lower surface of the lid will increase the pressure between the sealing surfaces to prevent leakage.
We have found that a minimum pressure of about 1.5 pounds square inch between the sealing surfaces, with container in an upright position, will provide the required seal while allowing the seal to be broken and the lid opened with reasonable effort. The container cap assembly of this invention is user friendly even to those individuals who have limited strength in the hands as a result of arthritis or tendinitis.
The angles θ and λ are important in achieving the above results. The angles θ and λ are preferably different with θ being larger than λ by about θ or more depending upon the size of the containers for which the container cap assembly is designed and λ can vary within the ranges of about 14° to 24° and 10° to 18°, respectively. Preferably θ and λ are within the ranges of about 16° to 20° and 12° to 16°, respectively. Most preferably θ is about 18° and λ is about 14°.
The cap body and lid are preferably injection molded from polypropylene having a Rockwell R hardness of between about 60 and 100 and most preferably about 80. We have found that a nominal wall thickness of 0.070″ for the cap body and lid member provides adequate strength for the assembly. We have also found that a wall thickness t1 of about 0.045″ for the neck at the upper end of the lid flange is adequate to provide the necessary flexibility to allow the flange 22 to flex outwardly over the rounded edge 18d of the cap lid flange and snap into its locked position as shown in
The living hinge comprises a central section 26a and end sections 26b with the central section functioning like an over center spring, i.e., when the lid is rotated through a set angle from it's closed position, say about 70°-80°, the central section causes the lid to rotate beyond 90° and remain in that position as is illustrated in
A container cap assembly 12″ is illustrated in
A modified container cap assembly 30 is shown in
It may be thus seen that the objects of the present invention set forth herein, as those made apparent from the foregoing description are efficiently attained. While preferred embodiments of the invention have been set forth for purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
Claims
1. A container cap assembly for providing a closure for large mouth containers having male threads surrounding one or more openings comprising:
- an annular cap body formed having a lower and upper section, the lower section having an outer surface and an inner surface defining female threads for cooperation with matching threads on the container, the upper section forming a generally horizontally inwardly extending shelf joined to an inwardly and upwardly extending flange, the flange defining a sealing surface which tapers outwardly at an acute angle with respect to the vertical in the unstressed condition; and
- a lid member pivotally hinged to the cap body whereby the lid member is arranged to pivot to a closed position in which said one or more openings in the container is closed and an open position in which un obstructed access is provided through the opening(s) in the container, the lid member having a top and bottom surface, a downwardly extending peripheral skirt arranged to overlie the body shelf in the closed position, and a downwardly extending inner flange, the lid flange defining an interior sealing surface which tapers inwardly at an acute angle with respect to the vertical in the unstressed condition, the lid flange being arranged to snap over the cap body flange to secure the lid member in a closed position when the lid member is pressed downwardly with the sealing surfaces forming an interference fit to provide a liquid tight seal between the cap body and lid member.
2. The container cap assembly of claim 1 wherein the cap body and lid member are integrally molded including a living hinge pivotally connecting the lid member to the cap body.
3. The container cap assembly of claim 2 wherein the lid member peripheral skirt has an outer surface arranged to be aligned with the outer surface of the cap body lower section in the closed position.
4. The container cap assembly of claim 2 wherein the sealing surfaces of the cap body and lid member flanges are oriented at angles of θ and λ to the vertical, respectively.
5. The container cap assembly of claim 4 wherein θ≠λ.
6. The container cap assembly of claim 5 wherein θ and λ are within the ranges of about 8° to 24° and 10° to 18°, respectively.
7. The container cap assembly of claim 6 wherein θ and λ are within the ranges of about 15° to 21° and 12° to 16°, respectively.
8. The container cap assembly of claim 2 wherein the cap body and lid member are injection molded from a plastic having a Rockwell R hardness of between about 60 and 100.
9. The container cap assembly of claim 8 wherein the plastic has Rockwell R hardness of about 80.
10. The container cap assembly of claim 2 wherein the difference between θ and λ is greater than 20.
11. The container cap assembly of claim 10 wherein θ is about 18° and λ is about 14°
12. The container cap assembly of claim 11 wherein the cap body and lid member are made of polypropylene.
13. The container cap assembly of claim 1 wherein the cap body and lid member are molded as separate pieces.
14. The container cap assembly of claim 13 wherein the sealing surfaces of the cap body and lid member flanges are oriented at angles of θ and λ to the vertical, respectively.
15. The container cap assembly of claim 13 wherein θ≠λ.
16. The container cap assembly of claim 13 wherein θ and λ are within the ranges of about 8° to 24° and 10° to 18°, respectively.
17. The container cap assembly of claim 13 wherein θ and λ are within the ranges of about 15° to 21° and 12° to 16°, respectively.
18. The container cap assembly of claim 13 wherein the cap body and lid member are injection molded from a plastic having a Rockwell R hardness of between about 60 and 80.
19. The container cap assembly of claim 13 wherein the plastic has Rockwell R hardness of about 80.
20. The container cap assembly of claim 13 wherein the difference between θ and λ is greater than 2°.
21. The container cap assembly of claim 13 wherein θ is about 18° and λ is about 14°
22. The container cap assembly of claim 13 wherein the cap body and lid member are made of polypropylene.
23. The container cap assembly of claim 1 wherein each of the flanges terminate in a free edge, the inner surface of the lid flange curving outwardly below the sealing surface thereof to engage the free edge of the cap body flange and flex said lid flange outwardly as the lid flange is snapped over the cap body flange.
24. The container cap assembly of claim 23 wherein θ>λ
25. The container cap assembly of claim 24 and further including a downwardly extending tongue formed integrally with the peripheral rim, the tongue terminating in an outwardly extending finger engaging portion to aid a user in opening the lid member.
26. The container cap assembly of claim 13 wherein the hinge is formed by a pair of space axle stubs formed integrally with the lid member and opposite the tongue and a pair of upwardly extending cooperating spaced slots in the cap body member, the spaced slots terminating in semi-cylindrical bores for receiving the axle studs.
27. The container cap assembly of claim 26 wherein the slots have a slightly smaller width than the diameter of the axle studs to allow the axle studs to be snapped into the cooperating bores and wherein the axle studs are formed with an extension on one side thereof to provide a resistance to the rotation of the lid member through a preselected angle so that once the lid is rotated through said angle the lid will be held in an open position allowing unobstructed access to the opening in the container.
28. The container cap assembly of claim 1 further including a releasable handle connected to the cap body.
29. A container cap assembly for providing a closure for large mouth containers having male threads surrounding an open end thereof comprising:
- an annular cap body having a lower and an upper section, the lower section having an outer surface and an inner surface defining female threads thereon for cooperation with matching threads on the container, the upper section forming an annular upwardly extending flange surrounding the container opening;
- a lid member having a top surface, a bottom surface and a downwardly extending flange; and
- a hinge pivotally connecting the lid member and the cap body whereby the lid member is arranged to pivot between a closed position in which the opening in the container is closed and an open position in which unobstructed access is provided through the opening in the container, the flanges having interlocking sealing surface in the closed position with the sealing surfaces of both flanges extending outwardly at an acute angle to the vertical.
30. The container cap assembly of claim 29 wherein the sealing surfaces of the cap body an lid member flanges are oriented at angles of θ and λ to the vertical, respectively.
31. The container cap assembly of claim 30 wherein θ≠λ.
32. The container cap assembly of claim 31 wherein θ and λ are within the ranges of about 8° to 24° and 10° to 18°, respectively.
33. The container cap assembly of claim 32 wherein θ and λ are within the ranges of about 15° to 21° and 12° to 16°, respectively.
34. The container cap assembly of claim 32 wherein the cap body and lid member are injection molded from a plastic having a Rockwell R hardness between 60 and 80.