Abstract:
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.

Description:
RELATED APPLICATION  
       [0001]     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 INVENTION  
       [0002]     The 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 ART  
       [0003]     There 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.  
         [0004]     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.  
         [0005]     Threaded lids generally include gaskets, but are not handy to use, especially for large mouth containers.  
         [0006]     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&#39;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.  
         [0007]     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.  
         [0008]     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.  
         [0009]     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 INVENTION  
       [0010]     The 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.  
         [0011]     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.  
         [0012]     In a preferred embodiment the cap body and lid member are molded as a single piece connected together by a living hinge.  
         [0013]     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.  
         [0014]     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.  
         [0015]     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  
       [0016]      FIG. 1  is a perspective view of a container cap assembly as mounted on a large mouth container;  
         [0017]      FIGS. 2 and 3  are top plan views of the disassembled cap body an lid member, respectively;  
         [0018]      FIG. 4  is a bottom view of the lid member.  
         [0019]      FIGS. 5 and 6  are side elevational views of the cap body and lid member, respectively;  
         [0020]      FIG. 7  is a side elevational view of the assembled cap body and lid member showing the lid being rotated toward a closed position;  
         [0021]      FIG. 8  is a side elevational view of the cap body and lid member with the lid in a closed position;  
         [0022]      FIGS. 9 and 10  are side and front elevational views of an alternative embodiment of the invention in which the cap body is provided with a rotatable handle;  
         [0023]      FIG. 11  is an enlarged cross-sectional view of the front of the assembled lid and cap outlined in the circle of  FIG. 8  showing the sealing surface of the lid and cap flanges providing an interference fit along a ring circumscribing a portion fo such surface;  
         [0024]      FIG. 12  is an enlarged cross-sectional view of the cap body flange of  FIG. 11  illustrating the angular orientation of the sealing surface thereon;  
         [0025]      FIG. 13  is an enlarged cross-sectional view of the lid flange of  FIG. 11  illustrating the angular orientation of the sealing surface thereon;  
         [0026]      FIG. 14  is an enlarged cross-sectional view of the portion of the cap body circled in  FIG. 5  showing the lid Axle receiving slot with a lid axle disposed therein;  
         [0027]      FIG. 15  is a broken away perspective view of one of the lid axles and adjacent support;  
         [0028]      FIG. 16  is a perspective view of another preferred embodiment of the present invention mounted on a container in which the assembly is molded as a single piece with a living hinge connecting the lid to the cap body;  
         [0029]      FIGS. 17 and 18  are top and bottom plan views, respectively, of the cap assembly of  FIG. 16 ;  
         [0030]      FIGS. 19 and 20  are side elevational views of the cap/lid assembly of  FIG. 15  with the lid in a closed position ( FIG. 19 ) and in a partially open position ( FIG. 20 );  
         [0031]      FIG. 21  is a perspective view of another embodiment of a single piece cap assembly in which the central portion of the lid top surface is planar to allow containers equipped with such cap assemblies to be stacked one on top of another; and  
         [0032]      FIG. 22  is a perspective view of yet another embodiment in which the cap body is formed with a top wall having a plurality of openings therein for dispersing condiments and the like.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]     Referring more particularly to  FIG. 1 , there is shown a pictorial view of a container  10  having a neck portion  11  on which is commonly formed an external thread (not shown). It should be readily understood that container  10  is illustrative of various types and sizes of containers, such as bottles, jars, and the like, that hold liquids as well as dry food products.  
         [0034]     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.  
         [0035]     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  16   b  on the interior surface  16   a  thereof. See  FIG. 12 . The outer surface  16   c  of the lower section surrounds the neck of the container, as is illustrated in  FIG. 1 . The lower section or wall  16  is formed with a hinge housing in the form of two spaced hubs  16   d  which define upwardly extending slots  16   e  terminating in semicylindrical bores  16   f  for receiving a pair of stub axles formed on a lid member to be described. See  FIG. 14 .  
         [0036]     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  ( FIG. 12 ). The rib section includes a generally inwardly extending horizontal shelf  19   a  and a vertically extending stub wall  19   b . The flange  18  has an interior surface  18   a  providing substantially unobstructed access to the interior of the container when the lid is in the open position. The flange  18  terminates at its upper end in a substantially flat peripheral rim  18   b.    
         [0037]     The flange  18  defines an inner sealing surface  18   c  which extends downwardly from the exterior corner  18   d  of the rim at an angle of θ degrees with respect to the vertical. A rounded corner  18   e  is formed between the lower end of the sealing surface and the web section as is shown more particularly in  FIG. 12 . The bottom surface  18   f  of the flange forms a downwardly projecting lip  18   g  for sealingly engaging the top rim of the container  10 . The rim corner  18   d  preferably is relieved by a small radius e.g, about 0.040″.  
         [0038]     The lid member  20  has a slightly convex shaped top surface  20   a , a bottom surface  20   b  of matching curvature and a peripheral rim  20   c , ( FIGS. 3, 4 , and  8 ). A flange  22 , extending downwardly from the rim  20   c , is arranged to engage the exterior surface of the cap body flange and provide a substantially leak proof seal between the lid and cap body and also to releasably lock the assembly together, as will be more fully explained in connection with  FIGS. 11-13 . The flange  22  is provided with an interior sealing surface  22   a  which is joined to a lower rounded surface  22   b , terminating at a free end  22   c . The exterior surface  22   d  of the flange  22  is spaced from the interior surface  20   d  of the depending portion of the peripheral rim  20   c  as is illustrated in  FIG. 13 .  
         [0039]     The sealing surface  22   a  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  FIG. 13 .  
         [0040]     A downwardly extending hinge plate  20   e  is formed integrally with the lid peripheral rim and carries at it&#39;s lower end a pair of outwardly projecting axle stubs  20   f . During assembly of the lid and cap body, the axle stubs are forced into the semicylindrical bores  16   f  at the end of the slots  16   e  in the cap body. See  FIG. 14 . The slots are formed with a width slightly less than the diameter of the axle stubs to retain the lid on the cap body. The hinge plate includes protrusions  20   g  adjacent the fixed end of the axle stubs which engage the exterior surface of the cap body lower section when the lid is rotated to an angle of about 90° from its closed position. The protrusions tend to force the axles outwardly as the lid is rotated past the 90° angle until the lid is positioned about parallel to the plane of the cap body, i.e., when the lid has rotated through about 180°. The lid is held in this open position until a small force is applied to the lid to rotate it toward its closed position.  
         [0041]     A downwardly extending tongue  20   h  is positioned diametrically opposite the hinge and is formed integrally with the lid peripheral rim. The tongue  20   h  includes, at its lower end, an outwardly extending finger engaging member  20   i.    
         [0042]     During the closing mode, the lid member is pushed downwardly against the cap body and container causing the rounded end  22   b  of the sealing flange to engage the corner  18   d  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  FIG. 11 . This action eliminates the need for a separate latching mechanism as required, for example, in the &#39;314 patent. At the same time the sealing surfaces of the two flanges form substantially a line or narrow annular band contact  24  on or adjacent the rounded corner  24  at the upper end of the cap body flange. See  FIG. 11 . It is to be noted that a rib having s small radius adjacent the top of the cap body sealing surface, instead of the rounded corner, would also serve to provide an effective line seal.  
         [0043]     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.  
         [0044]     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.  
         [0045]     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°.  
         [0046]     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 t 1  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  18   d  of the cap lid flange and snap into its locked position as shown in  FIG. 11  when the lid is pressed downwardly in a closing mode. The thickness t 2  of the lid flange  22  at the intersection of the sealing surface  22   a  and the rounded terminal end  22   b  is preferably about 0.060″ to be compatible with the foregoing dimensions. The periphery of this intersection is obviously greater than the periphery of the adjacent section of the flange  18   h  (in the closed position) to releasably secure the lid to the cap body in the closed position. See  FIG. 11 .  
         [0047]      FIGS. 9 and 10  illustrate a container cap assembly in which the cap body is provided with integrally molded handle receiving housings  24  located on opposite sides of the outer wall  16   c . The housings form an inner slot  24   a , terminating in a semicircular recess  24   b  and outer slot  24   c , a handle  26 , also preferably made of polypropylene, includes a circular disk  26   a  mounted to each end of the handle via a reduced diameter axle  26   b . Each end of the handle can be snapped into a respective inner slot to allow a user to conveniently carry the container.  
         [0048]      FIGS. 16-20  illustrate a preferred embodiment of the invention in which a container cap assembly  12 ′ is molded in one piece with a living hinge  26  connecting a lid member  20 ′ to a cap body or nut  14 ′. Other than the living hinge and a modified tongue design  20   h ′ the cap assembly  12 ′ is the same as the cap assembly  12  described previously. The corresponding sections of the cap body and lid member are designated with prime numerals, e.g., the lower cap body section is designated at  16   c′.    
         [0049]     The living hinge comprises a central section  26   a  and end sections  26   b  with the central section functioning like an over center spring, i.e., when the lid is rotated through a set angle from it&#39;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  FIG. 16 . The reverse action takes place during the closing mode except that the central section does have sufficient spring action to close the lid.  
         [0050]     A container cap assembly  12 ″ is illustrated in  FIG. 21 , which assembly is identical to that shown in  FIGS. 16-20  except that the lid member  20 ″ is formed with a depressed flat top central section  20   a ″ to receive the bottom of a container for nesting purposes.  
         [0051]     A modified container cap assembly  30  is shown in  FIG. 22  in which the upper section  32  of the cap body  30  is formed with a flange  32   a  like the flange  18  of  FIG. 5 , a top wall  32   b  circumscribed by the flange  32   a  and having a plurality of openings  32   c  therein for dispersing condiments and the like. The lid member  34 , shown in the partially open position, includes downwardly projecting bosses  34   a  which are in registry with and close the respective opening  32   c  in the top wall  32   b  of the cap body when the lid member is in the closed position. The sealing flanges and surfaces of the lid and cap body are the same as those shown in  FIGS. 11-13 .  
         [0052]     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.