Patent Publication Number: US-7594587-B2

Title: Removable locking container cover

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/732,811, filed on Nov. 2, 2005, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to removable covers for containers, and more particularly, to removable and reusable covers with a pour spout for use with microwavable containers. 
     BACKGROUND OF THE INVENTION 
     It is known to provide a removable cover for a container, such as a container of food or drink. Many such containers can be placed in a microwave oven to heat its contents. The cover or closure functions to prevent the contents of the container from spilling when the container is moved, or splattering when being heated in the microwave. However, many prior art container covers have suffered from deficiencies. Depending on their construction, they may be difficult to put on or to remove, or may be too easily removed, thereby resulting in inadvertent removal of the cover. 
     It is also known to have a cover with a hole in it, such as a spout, for pouring out the container contents, or for drinking the contents directly from the container. However, a number of prior art container covers provide a poor seal between the cover and the container, such that when the container contents are poured out some of the contents leak from between the container and the cover. 
     It is desirable to provide a cover which is easier to put onto and take off of a container, inhibits inadvertent removal, and that seals more dependably. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a container cover for use with a container having a neck with an outer bead ring or lip. In one aspect, the container cover comprises a lid with a spout hole (or pour spout), a skirt extending downward from the circumference of the lid, a concentric plug seal extending downward from the bottom of the lid disposed inside the skirt, a spout door hingeably connected to the top of the lid, and a plurality of locks each having an inwardly projecting wedge, which hold the cover in place on the container by engaging the container neck bead ring. 
     When the cover is installed on the container, the wedges on the inside of the skirt engage the outside of the container neck, and the plug seal sealingly engages the inside of the container neck. In an embodiment, the lid is circular and fits on a container neck with a circular cross section. The cover has a flexing lock disposed at the rear of the lid, and two non-flexing locks disposed on the opposite side of the cover from the flexing lock. 
     A spout plug seal is located on the bottom of the spout door and is designed to snap into place in the spout hole, thereby sealing the spout hole. A lifting tab on the front edge of the spout door is used to unsnap or release the door and open the spout hole. When open, the lifting tab on the spout door preferably snaps into place under a nub projecting from the inside of the flexing lock, thereby holding the door in an open position and also preventing the flexing lock from being inadvertently unlatched. 
     Other objects, aspects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description, when considered in conjunction with the appended claims and the accompanying drawings briefly described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustrating the invention, there is shown in the drawings embodiments that are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and constructions particularly shown. In the drawings: 
         FIG. 1  is a partial cutaway perspective view of a container cover according to a preferred embodiment of the present invention, shown with the spout door closed, installed on a container. 
         FIGS. 2A and 2B  are top and bottom perspective views, respectively, of the cover of  FIG. 1 , shown with the spout door open, without the container. 
         FIGS. 3A ,  3 B and  3 C are a top view of the cover of  FIG. 1 , an enlarged view showing the flexing lock, and an enlarged view showing a non-flexing lock, respectively. 
         FIGS. 4A ,  4 B and  4 C are a side cross-sectional view of the cover of  FIG. 1 , an enlarged view of the front of the spout door showing the lifting tab and the spout door plug seal snap, and an enlarged view showing the flexing lock, respectively. 
         FIG. 5  is a bottom view of the cover of  FIG. 1 . 
         FIGS. 6A and 6B  are a rear view of the cover of  FIG. 1 , and an enlarged view showing the flexing lock, respectively. 
         FIG. 7  is a cross-sectional view of the cover. 
         FIGS. 8A and 8B  illustrate the top and cross-sectional view of an alternate embodiment of the present invention. 
         FIGS. 9A and 9B  illustrate the top and bottom view of an alternate embodiment of the present invention.  FIG. 9   c  is an enlarged section from  FIG. 9B   
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein like reference numerals identify like elements,  FIG. 1  shows a container  100  in combination with a removable locking container cover  110  according to the present invention. The container  100  has an upper end  120  having an open mouth. A removable top or shipping seal  122 , such as a peel-off top with a ring-like opening tab, may be sealed to a rim or outer edge of the container  100  to prevent the contents of the container from spilling. The user removes the top prior to use to expose the contents (not shown) of the container  100 . With the top removed, the container cover  110  may be attached or reattached to the container upper end  120  before moving or heating the container to reduce the risk of the contents spilling while the container is carried or splattering when the container is heated. 
     The container  100  may be of any size or shape and may be fabricated from any of a variety of materials. Preferably, the container  100  contains food products which are heated in a microwave oven prior to consumption. Therefore, container  110  is preferably fabricated from a material suitable for use with food products and for heating in a microwave, for example a thermoplastic material such as polypropylene formed by injection molding. The container  100  preferably includes a neck or rim with a protruding lip having an outer bead ring  130 , or similar structure proximate to its upper end  120 . The outer bead ring  130  may be disposed directly adjacent to the upper end  120  of the container  100  or in close proximity thereto. While the container  100  and cover  110  are illustrated as each having a substantially circular shape, it will be appreciated that the teachings of the invention are applicable to a variety of other shapes. The following description and embodiments of the invention are not intended to describe all cover/container combinations, but are merely illustrative of how the teachings of the present invention may be employed in the context of a preferred container configuration. 
     Referring to  FIG. 1 , the container cover  110  includes a lid  140 , having a top, a bottom, a circumferential edge  145 , and a spout hole. When installed on the container, the top of the lid faces away from the container, and the bottom of the lid faces into the container. The cover also includes a skirt  150  extending downward from or near the circumferential edge of the lid  140 . The skirt  150  has an inner surface (or wall) and an outer surface (or wall). When installed on the container, the outer wall faces away from the container, and the inner wall faces toward the container, and is preferably shaped to fit snugly around the outside of the container neck and/or outer bead ring. 
     Container cover  110  also includes a spout door  160 . The spout door is attached to the top of the lid preferably via at least one hinge  165 . The spout door has an edge  170 , and a point on the edge furthest from the hinge defines a front edge of the door. The door is shown in  FIG. 1  in its closed position. When the door is in its closed position, the top of the door faces the same direction as the top of the lid, and the bottom of the door faces the same direction as the bottom of the lid. The hinge is disposed on the lid so that the spout hole is completely covered by the door when the door is in its closed position. A point on the circumference of the lid nearest the front edge of the door when the door is in its closed position defines the front of the lid, and a point on the circumference of the lid opposite the front of the lid defines the rear of the lid. 
       FIG. 2A  is a top perspective view of the cover of  FIG. 1 , shown with the door in its open position, uncovering spout hole  200  with edge  205 , and showing the bottom of the spout door. The bottom of the spout door comprises a spout plug seal  210  shaped to fit snugly and sealingly in the spout hole when the door is in its closed position. The hinge  165  is preferably a split level living hinge (e.g., molded integrally to the lid.) Recessed area  225  in the top of the lid is shaped so that when the door is in a closed position, the bottom surface of the door  220  fits into a homologously shaped recess on the lid  225 . The portion of the top of the lid adjacent to the spout hole preferably has a concave or sloped surface  230  to help control any spillage of the contents of the container. The container cover has a lip  240  extending upward from the circumferential edge of the lid, which also helps control any spillage of the contents of the container. The lip  240  has a reduced height or notch  245  at the part of the circumference closest to the spout hole, to help control the flow of the contents when being poured out through the spout hole  200  or when the user drinks directly from the spout hole. 
     The container cover is held onto the container by a plurality of locks, one of which is a flexing lock  250  at the rear of the lid. The locks engage the outer bead ring on the neck of the container, as will be described hereinafter. 
       FIG. 2B  is a bottom perspective view of the cover of  FIG. 1 . The bottom of the lid  140  has a protruding area  260  with a profile similar to the profile of the spout door in its closed position. Plug seal  270  is preferably formed concentrically to the skirt  150  and has a smaller diameter than the skirt. The plug seal  270  extends from the bottom of the lid and preferably connects along its entire length to the bottom of the lid. The plug seal has an outer wall shaped to preferably fit snugly and sealingly against the inside of the neck or rim of the container. A plurality of stop ribs  280  preferably extend from the inside of the skirt and/or the bottom of the lid. The stop ribs are located so that, when the cover is installed on a container, the stop ribs touch the top of the container neck limiting the downward movement of the cover onto the container. 
       FIG. 3A  is a top view of the cover  110  of  FIG. 1  with the door  160  in a mostly open position. A lifting tab  300  is located on the front edge  305  of the door. When the door is in its fully open position, the end of the lifting tab  300  engages a nub  310  that protrudes from the inside of a flex lock panel  315 , so that the door  160  is held in its open position by the nub  310  and the lifting tab  300  prevents the flex lock panel  315  from moving into an unlatched position. There is at least one and more preferably at least two non-flexing locks  320  located on or near the front of the lid. In the illustrated embodiment, each non-flexing lock  320  is a wedge formed in the shape of a truncated tear drop. It should be readily apparent that other shapes could be used, such as a bulbous protrusion. The radially inmost point of each wedge is preferably located at an angle θ from a longitudinal axis  325 , which is preferably in a range of approximately 135 degrees to approximately 155 degrees, and is most preferably 144 degrees. The wedges  320  are preferably equally spaced from and on opposite sides of the longitudinal axis  325 . As will be discussed in more detail below, there is also at least one flexing lock located on the rear of the lid. The flexing lock also includes a wedge  350 . The wedge  350  preferably is located on the longitudinal axis  325 . 
       FIG. 4A  is a side cross-sectional view of the cover of  FIG. 1  taken along lines  4 A- 4 A in  FIG. 3A . This figure more clearly illustrates the door in a mostly open position. As the door swings into its fully open position, the lifting tab  300  will engage the nub  310  on the inside of the flex lock panel  315 , holding the door in its open position, and preventing the flexing lock from inadvertently being unlatched. Spout plug seal  210  is shown on the bottom of the door (facing upward in  FIG. 4A ). As the door swings into its fully closed position, the spout plug seal  210  will snugly and sealingly fit against the edge  205  of the spout hole  200 , and spout plug seal snap  325  will engage the edge  205  of the spout hole. 
     The level of the top of the wedges of the flexing and non-flexing locks (i.e., the vertical location of the tops of the wedges on the skirt) is indicated by dashed line  330 . The bottom of a stop rib  280  is also visible. The distance d between the bottom of the stop ribs  280  and the top of the lock wedges  330  is sized so that when the cover is installed on a container having a bead ring  130  on its neck, the bottom of the stop ribs  280  touches the top of the neck or the bead ring  130 , and the lock wedge engages the bottom of the container bead ring  130 , thereby locking the container cover in place. 
       FIG. 5  is a bottom view of the cover of  FIG. 1 . The truncated tear drop-shaped wedges  340  of the two non-flexing locks  320  are visible from the bottom in the figure, with the feathered part of the wedges pointing toward the flexing lock. The wedge  350  of the flexing lock is also visible, as are the stop ribs  280  extending from the inside of the skirt. 
       FIG. 6A  is a rear view of the cover according to one embodiment of the invention, and  FIG. 6B  is an enlarged rear view of the cover, showing the flexing lock  250 . The flexing lock comprises a flex lock panel  315  preferably of substantially the same thickness as the skirt  150 , disposed so that it does not interfere with the plug seal when the cover is installed. The lock panel has an inside, an outside, a top edge, a left edge and a right edge. In the illustrated embodiment, an elastically deformable hinge attaches the flex lock panel to the skirt. More particularly, a deformable pivot bar  400  is formed on each of the left and right sides of the flex lock panel  315  at an intermediate point along the height of the panel. The pivot bars are connected to the skirt. Forming the pivot bars as part of the skirt and not attached directly to the plug seal  270  results in the flex lock remaining comparatively cooler during heating since the flex lock is not in direct contact with the interior of the container. 
     The panel, pivot bars and the skirt are all preferably formed as an integral injection molded unit. The outside surface of the flex lock panel  315  preferably has a textured area  410  substantially adjacent to the top edge of the panel. The textured area helps keep the fingers of a user from slipping, such as when removing the cover from the container. 
       FIG. 3B  is an enlarged top view of the cover, showing the flexing lock. The locking wedge  350  extends inward from an inside surface of the flex lock panel  315 . In a latched position, the locking wedge engages the lower edge of outer bead ring of the container. In an unlatched position, the wedge  350  is released from the outer bead ring. The nub  310  extends from the top of the inside surface of the flex lock panel. Pawls  420  may be formed on the back of the pivot bars  400  at a location which allows them to contact the top surface of the container neck when the flexing lock is latched. This provides additional support for the flex lock panel when it is actuated from the latched to the unlatched position since the pawls push on the top surface of the container neck, thereby assisting in the pivoting of the flex lock panel. 
       FIG. 4B  is an enlarged cross-sectional view of the tip end portion of the spout door  160 . The lifting tab  300  extends from the front edge of the door, and is designed to engage with the nub  310  ( FIG. 4C ) on the inside of the flex lock panel when the door is in its open position, thereby holding the door open, as hereinbefore described. The spout plug seal snap  325  protrudes from the spout plug seal  210 , and engages an edge of the spout when the door is in its closed position, thereby holding the door closed and sealing the spout hole shut, as hereinbefore described. 
       FIG. 4C  is an enlarged cross-sectional view of the flexing lock  250 . The nub  310  is shown extending inward from the top of the inside surface of the flex lock panel  315 . The textured area  410  is shown on the top of the outside surface of the flex lock panel  315 . The locking wedge  350  extends inward from the bottom of the inside surface of the flex lock panel  315 . 
       FIG. 3C  is an enlarged partial top view of the cover, showing a non-flexing lock  320 . As described above, the non-flexing lock  320  includes the locking wedge  340  which extends from the inner wall of the skirt  150 . The wedge  340  can more clearly be seen in this figure in the shape of a truncated tear drop, with the feathered edge  700  extending circumferentially away from the bulbous end (and from the spout.) An open slot  710  is preferably formed between the circumference of the lid and the top circumference of the skirt, substantially adjacent to the non-flexing lock wedge  340 . 
       FIG. 7  is a cross-sectional front view of cover  110 . As hereinbefore described, the open slots  710  are substantially adjacent to the non-flexing lock wedges  340 . The plug seal  270  extends from the bottom of the lid  140 , concentric with the skirt  150  which extends downward from the circumference of the lid. The stop ribs  280  extend from the skirt and the lid, and do not interfere with the plug seal  270  when the cover is installed on a container. Distance d between the bottom of the stop ribs  280  and the top of wedges  340  is sized so that when the cover is installed on a container having a bead ring  130  on its neck, the bottom of the stop ribs  280  touches the top of the neck or bead ring  130 , and the wedges engage the bottom of the bead ring  130 , thereby locking the container cover  110  in place on the container  100 . Although the illustrated embodiment includes open slops  710 , it should be readily apparent that the slots are not necessary in the cover. 
     The container cover of the present invention is preferably formed from thermoplastic material such as polypropylene in a one piece construction using an injection molding process. The container cover preferably has a hinged drink door and three integral locks. The cover is preferably microwavable and easily removed and reapplied to the container by the user. It is contemplated that the cover can be locked onto the top lip of the container during an assembly process at the factory, keeping the top surface of the container completely sealed, clean and dry during shipping and storage. To remove the cover cap, the user presses inward on the textured portion of the flex lock panel of the flexing lock. This mechanical action moves the locking wedge lock away from the container bead ring, while the pawls on the pivot bars push down on the top of the container neck, making it possible to lift the back section of the cover. Simultaneously as the user lifts up on the back section of the cover, the cover is moved forward in an arc, disengaging the two front non-flexing locks. 
     After the user has removed the cover, the user opens the container, such as by pulling upward on the now exposed metal ring tab of a sealed container top, completely separating the top from the container and discarding it. Next the user replaces the cover cap with the door in the open position and places the container with cover into a microwave. When the user places the door into its open position it makes a distinctive snapping sound as the lifting tab engages the nub on the flex lock panel, securing the door in its open position. The door is left open during the microwaving process to vent steam generated in the container by the heating process. 
     In a preferred container/cover configuration, the container has a circular neck, and the cover has one flexible lock located at the rear of the cover and two non flexing locks, one on each side of the spout. The two non-flexing locks are formed as part of the inner wall of the skirt, and the flexing lock is part of the inner wall of the flex lock panel. This lock approach leaves the plug seal completely free from all connecting obstructions that create unwanted shrinkage and lead to leakage problems. The stop ribs preferably do not touch the plug seal or cause seal distortions. Because of the uninterrupted plug seal, it is completely round and seals 360 degrees against the inside of the neck of the container. Locating the flexible lock on the skirt allows for simple assembly by simply placing the cover over the container and pressing the cover directly down onto the container. When the flexible lock is engaged it makes a distinct snap sound as it slides over the container bead. The locking action can also be felt by the user through the finger tips as it locks over the container bead. 
     The two non-flexing front locks are shaped as truncated teardrops so that they will slip over the container bead as the cover is removed. The two actions of unlatching the flexing lock and lifting the cover need to be done simultaneously to remove the cover. The feathered end of the teardrop points toward the flexing lock, so that the cover can be peeled off of the container bead. Directing the feathered end of the truncated teardrop toward the flexing lock also creates a smooth entry for the container bead to start and slide over the lock as the cover cap is taken off. 
     A safety feature of the preferred embodiment is that when the door is placed in its open position, it prevents the flexible lock from being inadvertently unlocked. When the door is placed in its open position, the lifting tab engages a nub on the inner top surface of the flexing lock. This prevents a user from inadvertently depressing the flexing lock and accidentally removing the cover. This reduces the risk of the contents of the container spilling onto the user. The cover can only be unlocked and removed from the container when the door is not in its open position. 
     Although the above embodiment included a spout for drinking or pouring the contents of the container, the present invention is not limited to such a configuration. Referring to  FIGS. 8A and 8B , an alternate embodiment of the invention  500  is shown that includes the flexible lock  502  and non-flexible locks  504 , but does not include a spout. In this embodiment, the cover  500  is simply removed in order to gain access to the contents. As shown, one or more vents  506  are formed in the cover. In the illustrated embodiment, the vents  506  are formed on the sloping transition section  508  between the lower annular surface  510  and the upper surface  512 . This configuration is designed to create a chimney effect whereupon the heat generated during cooking is channeled toward the center of the cover escapes through the vents. This keeps the locks and plug seal cooler. Thus, it results in less harm to the user and maintains a better seal. 
       FIGS. 9A-9C  illustrate an alternate embodiment of the invention with the drinking spout. In this embodiment  550 , in order to facilitate the opening and closing of the spout door  552 , the door plug seal  554  is modified to permit additional flexure. Specifically, the door plug seal wall  554  is formed with a different wall thickness in the front  558  and back  556 . Preferably the wall in the back  556  is thicker than the wall in the front  558 . 
     It will be apparent to those skilled in the art that various modifications and variation can be made in the configuration of the present invention without departing from the spirit or scope of the invention. It is intended that the present invention cover such modifications and variations provided they come within the scope of the appended claims or their equivalents.