Patent Publication Number: US-7594588-B2

Title: Removable locking container cover with slotted outer skirt

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation in part of U.S. patent application Ser. No. 11/542,547, filed on Oct. 3, 2006, 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 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 their 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 exemplary embodiments, the container cover comprises a lid with 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, 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. Two types of locks can be used, one type having a hinge that allows the wedge to pivot away from and disengage the bead ring, and the other type without a hinge. The lock without a hinge can be of two types, one type being non-flexing, and the other type provided with a slot extending through the skirt that allows the lock to flex to disengage the bead ring. The lid can optionally have a spout hole (or pour spout), and a spout door hingeably connected to the top of the lid. 
     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 hinged lock disposed at the rear of the lid. In an embodiment, the cover has two non-flexing locks disposed on opposite sides of the cover at the front of the lid. In another embodiment, the cover has two slotted flexing locks disposed on opposite sides of the cover at the front of the lid. 
     In an embodiment comprising a lid with a spout hole, a spout plug seal can be located on the bottom of the spout door and 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 can be 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 hinged lock, thereby holding the door in an open position and also preventing the hinged 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 an 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 hinged 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 hinged 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 hinged lock, respectively. 
         FIG. 7  is a cross-sectional view of the cover of  FIG. 1 . 
         FIGS. 8A and 8B  illustrate the top and cross-sectional side view of an alternate embodiment of the present invention. 
         FIGS. 9A and 9B  illustrate the top and cross-sectional side view of an alternate embodiment of the present invention.  FIG. 9C  is an enlarged section from  FIG. 9B   
         FIG. 10  is a partial cutaway perspective view of a container cover according to an embodiment of the present invention provided with slotted flexing locks, shown with the spout door closed, installed on a container. 
         FIG. 11  is a bottom view of the cover of  FIG. 10 . 
         FIGS. 12A and 12B  are an enlarged top view and an enlarged bottom view, respectively, of the cover of  FIG. 10 , showing a slotted flexing lock. 
         FIGS. 13A and 13B  are top and bottom perspective views, respectively, of the cover of  FIG. 10 , shown with the spout door open, without the container. 
         FIG. 14  is a cross-sectional view of the cover of  FIG. 10 . 
         FIGS. 15A ,  15 B and  15 C are top perspective, side, and bottom views, respectively, of an alternate embodiment of the present invention. 
     
    
    
     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 hinged 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 hinged 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 hinged lock panel  315  from moving into an unlatched position. There is at least one and more preferably at least two non-hinged locks  320  located on or near the front of the lid. In the illustrated embodiment, each non-hinged 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 hinged lock located on the rear of the lid. The hinged 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 hinged lock panel  315 , holding the door in its open position, and preventing the hinged 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 hinged and non-hinged 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-hinged locks  320  are visible from the bottom in the figure, with the feathered part of the wedges pointing toward the hinged lock. The wedge  350  of the hinged 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 hinged lock  250 . The hinged lock comprises a hinged 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 hinged lock panel to the skirt. More particularly, a deformable pivot bar  400  is formed on each of the left and right sides of the hinged 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 hinged lock remaining comparatively cooler during heating since the hinged 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 hinged 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 hinged lock. The locking wedge  350  extends inward from an inside surface of the hinged 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 hinged 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 hinged lock is latched. This provides additional support for the hinged 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 hinged 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 hinged 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 hinged lock  250 . The nub  310  is shown extending inward from the top of the inside surface of the hinged lock panel  315 . The textured area  410  is shown on the top of the outside surface of the hinged lock panel  315 . The locking wedge  350  extends inward from the bottom of the inside surface of the hinged lock panel  315 . 
       FIG. 3C  is an enlarged partial top view of the cover, showing a non-hinged lock  320 . As described above, the non-hinged 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 opening  710  is preferably formed between the circumference of the lid and the top circumference of the skirt, substantially adjacent to the non-hinged lock wedge  340 . 
       FIG. 7  is a cross-sectional front view of cover  110 . As hereinbefore described, openings  710  are substantially adjacent to the non-hinged 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 opening  710 , it should be readily apparent that the openings 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 can have 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 can press inward on the textured portion of the hinged lock panel of the hinged lock. Alternatively, the user can press upward and outward on the bottom of the hinged lock panel of the hinged 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-hinged locks. 
     In an exemplary implementation, 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 hinged 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 hinged lock located at the rear of the cover and two non hinged locks, one on each side of the front of the cover. The two non-hinged lock wedges are formed as part of the inner wall of the skirt, and the hinged lock wedge is part of the inner wall of the hinged lock panel. This lock approach leaves the plug seal completely free from all connecting obstructions that create unwanted shrinkage and can lead to leakage problems. The stop ribs preferably do not touch the plug seal or cause seal distortions. Because the plug seal is uninterrupted, it is completely round and preferably seals 360 degrees against the inside of the neck of the container. Locating the hinged 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 hinged 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-hinged 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 hinged lock and lifting the cover need to be done simultaneously to remove the cover. The feathered end of the teardrop points toward the hinged lock, so that the cover can be peeled off of the container bead. Directing the feathered end of the truncated teardrop toward the hinged 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 hinged lock from being inadvertently unlatched. When the door is placed in its open position, the lifting tab engages a nub on the inner top surface of the hinged lock panel. This prevents a user from inadvertently unlatching the hinged 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 fully open position. 
     Although the above embodiment includes a spout for drinking or pouring the contents of the container, the present invention is not limited to such a configuration. Referring to FIGS.  8 A and  8 B, an alternate embodiment of the invention  500  is shown that includes the hinged lock  502  and non-hinged 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  can be 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 . 
     In alternate embodiments, the skirt and non-hinged locks can be modified to permit flexure. Specifically, one or more non-hinged locks can be formed with a slot extending through the skirt and the non-hinged lock wedge. The slots are preferably about 0.06 inch wide and extend about 0.075 inch over the top of the lock wedge, and are preferably located substantially through the center of both non-hinged front locks, although other slot sizes and placements can also be used. The slotted wedges may be symmetrical in shape, rising gradually from the inside surface of the skirt to a thickest portion adjacent to the slot, although other shapes can be used. While  FIGS. 11 ,  12 A and  12 B show symmetrically shaped non-hinged lock wedges, it should be readily apparent that the non-hinged lock wedges could be teardrop shaped as shown in  FIG. 3C . 
       FIG. 10  shows a cover substantially similar to the cover of  FIG. 1 , but with a slot  600  added through the center of each non-hinged front lock.  FIG. 11  shows a bottom view of the cover of  FIG. 10 , showing symmetrical non-hinged lock wedges  340  provided with a central slot, and  FIGS. 12A and 12B  show enlarged top and bottom views, respectively, of a slotted non-hinged lock.  FIGS. 13A ,  13 B and  14  show perspective top, perspective bottom, and cutaway views, respectively, of the cover of  FIG. 10  showing slotted non-hinged front locks provided with slot  600  extending through skirt  150 , and through the center of symmetrical wedges  340 .  FIGS. 15A ,  15 B and  15 C show top perspective, side, and bottom views, respectively, of an alternative exemplary embodiment of the invention, substantially similar to the cover shown in  FIG. 8A , with the exception that the cover is provided with slots  600  extending through the center of symmetrical wedges  340  and skirt  150 , as described. 
     Providing the slots through the skirt and non-hinged lock wedges adds flexibility to the skirt and non-hinged locks. Splitting a single non-hinged lock wedge by the slot effectively forms two non-hinged lock wedges separated by the slot, promoting a tight, secure fit of the cover over the container. The slots allow the skirt and the non-hinged lock wedges to flex outward away from the container rim as the wedges pass over the container bead ring when the cover is applied or removed. When removing the cover, the slots in the skirt enable the lid to flex when the hinged lock is lifted, promoting easy removal of the cover. One portion of the wedge split by the slot can be pulled over the container bead ring slightly before the other portion. This provides the user with greater control of the cover when removing it from a container, reducing the possibility of accidentally spilling the container contents when removing the cover. 
     It has also been determined that, as an alternate to the user pivoting the hinged lock to disengage the locking wedge from the container rim bead, the user could, instead, simply lift the bottom edge of the hinged lock which results in reality easy disengagement of the locking wedge from the container rim bead. The user can then lift or peal the lid off of the container with minimal effort. 
     It will be apparent to those skilled in the art that various modifications and variations 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.