Patent Publication Number: US-7717267-B2

Title: Snap-lock twist-open card and blister package

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to card and blister type packages, and more particularly to a three piece package having fastening features that can be snapped into locking engagement and disengaged by rotation of the features. 
   2. Description of the Prior Art 
   Card and blister packages are widely used for packaging small articles of commerce. Typically such a package will have a clear plastic blister piece; i.e. open topped enclosure that has a flange. The card has one side coated with a layer of dry adhesive. At a typical packaging station the product is placed in the blister cavity of a supported blister piece, then the card is placed over the blister with its adhesive-coated side engaged with the blister flange. The subsequent application and removal of heat and pressure along the flange causes the adhesive to liquefy, and a bond is formed between card and flange. The liquid adhesive on the remainder of the card will return to its dry state and remain on the card. 
   Today it is an ecologically responsible practice to recycle packaging materials, and for card and blister packages this requires in the first instance to separate the plastic component from the paper-based card component. With conventional packages the separation of source materials is often not complete since portions of the card will remain adhesively attached to the flange of the plastic blister portion, and printed paper torn from the face of the card, and as mentioned above, a significant amount of dried adhesive will remain on the discarded card. 
   Another drawback with other conventional clamshell style packages is that, in the interest of providing a package that is secure against tampering and pilferage, they are becoming quite difficult for the ordinary purchaser to open, and this has even resulted in serious injury to the hand and fingers. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing it is a general object of the invention to provide an improved card and blister package and an alternative to conventional clamshell packages. 
   A more specific object is to provide a card and blister package that offers the highest level of security desired by the retailer, yet is relatively easy for the purchaser to open. 
   Another object is to provide a card and blister package that is ecologically sound by lending itself to easy and effective source separation of its plastic and paper-based components for recycling of the used package materials. 
   A further object is to provide a package that has a recyclable card free of adhesive residue, and a plastic blister portion that is free of paper residue transferred from the card. 
   Yet a further specific object is to provide a card and blister package-having components that can be easily snapped into a locking configuration, requiring little to no adhesive sealing to be effective, and which can be opened by rotation of novel integral locking caps. 
   These and other objects and advantages are provided by the present invention of a card and blister package that includes a clear plastic blister piece, a card, and a retainer piece. The blister piece includes an article-receiving cavity and a flange portion, and a plurality of first connector elements is spaced apart along the flange. The retainer ring includes a frame with a plurality of second connector elements spaced therealong, these second connector elements adapted for being snapped into locking engagement with the first elements. 
   The card has a plurality of openings, and the package has a closed configuration in which the card covers the blister cavity and the respective first and second connector elements are locked with each other by way of the card openings to secure the card between retainer frame and blister flange. The invention further features means on the respective connectors that allow them to be unlocked when the retainer connectors are rotated through about 90 degrees. There is a region/line of lessened structural integrity about each of the blister connector elements which is adapted to be severed so as to provide a disconnected segment that, inclusive of the connector element, can then be free to be rotated relative the remainder of the frame. 
   In one preferred embodiment the first connector elements comprise upwardly extending locking posts, and the second connectors are integral downwardly-opening locking caps More specifically, each of the blister locking posts has at least one side portion containing a generally concave locking cavity and the cap interior has resiliently deformable, inwardly projecting convex locking means that will resiliently deform when engaged by a locking post and then spring inwardly into locking engagement with the post locking cavity when the post is fully inserted in the locking cap. 
   In a preferred embodiment each of the integral locking caps is encircled by a line of lessened structural integrity in the body of the retainer ring whereby manual rotation of the cap relative to the retainer ring will cause separation along the line. Rotation of the cap of a locked package through about 90 degrees will move the locking means out of engagement with the locking cavities so as to free the cap for vertical separation from the post. 
   In one variant of the invention the second connector element includes a downwardly projecting member having at least one locking lug projecting outwardly from the lower end of the member and the first connector element has walls that define an opening for receiving the lower end of the member, and including at least one inwardly projecting resiliently deformable flap adjoining the opening and which flap is adapted to be engaged by the lug, whereby said second connector is locked into engagement with the first connector when said lug is moved downwardly against said flap to cause it to deform and then snap into engagement with the upper edge of the lug upon further downward movement of the lug. Rotation of the member through about 90 degrees will move the lug out of engagement with the flap and into the opening to allow the member to be vertically withdrawn. In this variant the retainer frame has a lower surface for engaging the card, and the severable segment is thinner than the remainder of the frame and spaced above the level of the frame lower surface to create an opening of insertion of cutting blades, and the line of lessened structural integrity comprises at least one transversely extending groove. 
   In yet another variant, on each side of a retainer connector there is an integral detachable strip in the retainer frame that is defined by transversely extending perforations, and a pull tab or ring at one end of the strip can be pulled in a manner to detach the strip from the retainer frame. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded perspective view of a snap-lock twist-open card-and-blister package according to the present invention; 
       FIG. 2  is a top perspective view of an assembled package according to the present invention; 
       FIG. 3  is a side elevational view of the package of  FIG. 2 ; 
       FIG. 4  is an enlarged perspective partial view of a package according to the present invention; 
       FIG. 5  is a sectional view taken along the line  5 - 5  of  FIG. 4 ; 
       FIG. 6  is an enlarged partial, perspective view of a corner portion of an assembled package according to the present invention; 
       FIG. 7  is a view similar to  FIG. 6 , but showing the locking cap rotated through 90° to its unlock position; 
       FIG. 8  is a sectional view taken along the line  8 - 8  of  FIG. 6 ; 
       FIG. 9  is a sectional view taken along the line  9 - 9  of  FIG. 7 ; 
       FIG. 10  is a sectional view illustrating vertical withdrawal of a rotated and detached locking cap from a locking post; 
       FIG. 11  is a partial perspective view of a corner portion of a variant of the present invention; 
       FIG. 12  is a partial perspective view of a portion of another variant of the present invention; 
       FIG. 13  is an exploded perspective view of yet another variant of a snap-lock twist-open card-and-blister package according to the present invention; 
       FIG. 14  is a top perspective view of the assembled package of  FIG. 13 ; 
       FIG. 15  is a side elevational view of the package of  FIG. 14 ; 
       FIG. 16  is an enlarged exploded perspective partial view of a package according to the present invention; 
       FIG. 17  is a partial enlarged perspective view of a corner region of the package of  FIG. 14 , showing a retainer segment in locked position; 
       FIG. 18  is a view similar to  FIG. 17 , but showing a retainer segment rotated through 90° to its open position; 
       FIG. 19  is a partial bottom view of connector elements in locked configuration; and 
       FIG. 20  is a view similar to  FIG. 19  showing connector elements in open configuration. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings,  FIG. 1  shows that in a preferred embodiment of a snap-lock twist-open card and blister package  13  according to the present invention the main components comprise a retainer ring  17 , a card  19  and a blister piece  21 . Ring  17  and blister  21  are each formed using techniques known in the plastics molding industry. Blister piece  21  has article-receiving cavity  23 , and has locking posts  27  that extend from flange  25 . 
   As shown in  FIG. 4 , and best in  FIG. 5 , locking post  27  have a pair of opposing beveled or slanted upper edges  29 , and a pair of opposing, transversely extending concave locking cavities  31  aligned below the respective slanted edges  29 . As shown in  FIG. 4  and  FIG. 9  rotationally at 90 degrees from the cavities  31 , are opposed generally vertical faces  35 . 
     FIG. 1  illustrates how the card  19  is provided with openings  20  for receiving posts  27 . 
     FIG. 5  shows that the downwardly opening cap  33  has convex transverse locking protuberances  39 . Conventional plastics forming techniques are used to provide, in a predetermined manner, the protuberance and cap wall structure with the desired strength, flexibility and resiliency to allow the protuberances  39  to be resiliently urged apart when they are pushed into slidable engagement with the post chamfered edges  29  when a package is closed, in a manner to be described. 
     FIG. 4  shows how each cap  33  is encircled by a line  43  of perforations in the body of retainer ring  17 . This provides a corresponding number of bridging segments that are designed to shear under torque generated when a cap is unlocked, in a manner to be described. Within circle  43  there is a skirt-like portion  45  upon which an arrow  49  for indicating the twist-open direction, is imprinted. 
   Closing and locking a package  13  occurs as follows. After articles are placed in the blister cavity  23 , the locking posts  27  are inserted through the openings  20  of the card  19 . Then the locking caps  33  of the retainer ring are aligned with the posts  27  as  FIG. 4  illustrates, and then moved downwardly towards engagement with the posts as suggested in  FIG. 5 . It can be appreciated, by reference to  FIG. 5  how the cap protuberances  39  will slideably engage the chamfered edges  29  of a post, so as to resiliently spread apart the protuberances, and how further insertion will allow the flexed protuberances  39  to “spring” or snap into engagement with the twin cavities  31 , to provide a locked configuration as  FIG. 8  shows. 
     FIGS. 2 and 3  are views of a completed package  13 . 
   Package  13  can be unlocked and opened as follows. A locking cap  33 , as shown in  FIGS. 6 and 7 , can be grasped by hand and then rotated for a quarter turn, i.e. 90 degrees, in the anti-clockwise direction indicated by the imprinted arrow  49 . A moderate amount of torque will suffice to cause separation along line  43 , as  FIG. 7  shows. This provides the cap  33  with a skirt or flange  45  of material. This quarter turn to the position shown in  FIG. 7  also moves the locking protuberances  39  out of the cavities  31  to a position adjoining the generally vertical faces  35 . Upward movement of the protuberances  39  is thereby unrestrained, and the cap  33  including skirt  45  can then be disengaged from the pin  33  as  FIG. 10  shows. 
     FIG. 11  shows the corner region of a retainer of a variant of the present invention, which is similarly constructed to the afore-described package  13 , and includes a retainer ring  117  and locking cap  133 . This variant differs by having no encircling perforations about the cap  133 . Instead there are raised transverse portions  140  that are designed to be conveniently engaged by a suitable cutting tool, such as scissors. It should be appreciated that when both portions  140  are severed, the cap  133  and the adjoining segment of ring material can be rotated to unlock the cap. 
     FIG. 12  shows the corner region of an additional variant  153 , also similar to the package  13 , having retainer ring  157  and locking cap  159 . This variant employs pull-tab elements  160 , each having an integral strip  165  bounded by the twin perforation lines  167 , and a pull ring  163 . To open the package, it should be appreciated how the pull rings can be manipulated to cause breakage along the lines  167  which will free up the cap  159  and adjoining material for rotation. 
     FIG. 13  shows another variant  213  of the invention that has a retainer ring  217  including frame  218  and connector elements  223 . There is a card  219  that has holes  220  that are alignable with the connector elements  223 . The blister piece  221  completes the package, and has article-receiving cavity  224 , a flange portion  225  and connector elements  227 , which are designed to engage card openings  220 . 
   The enlarged view of  FIG. 16  best shows that a typical package corner has a connector element  223  having shaft  234  and locking lugs  236  on opposing sides of its lower end. ( FIG. 19  shows both lugs  236 ). Note that shaft  234  extends downwardly from a retainer frame web portion  237  that is thinner than frame  218  and spaced above the level of bottom surface  238  retainer frame  218 .  FIG. 15  best shows how, in the assembled package  213  this feature will provide a space  240  between the top of the card  219  and the retainer web portion  237 . This is sufficient to allow insertion of the blades of a cutting tool, such as a pair of scissors, when the package is opened in a manner to be described. In this regard,  FIG. 16  further shows how web  237  is provided with transverse cutting guides on both sides of the connector element  223 , in the form of notches or grooves  239 , the notches providing transverse paths of reduced thickness to facilitate cutting. The transverse lines E help indicate the direction of the notches  239 . An arrow  250  is imprinted in the ring frame to show the direction of rotation for unlocking of a package when a rotatable segment is created, in a manner to be described hereinafter. 
     FIG. 16  also shows that the blister connector element  227  had a cylindrical wall  228  which can be received by the card opening  220  to register and laterally stabilize card  219 . Note that the top of blister connector  227  has resiliently deformable opposing flaps  240  that are engagable by the two opposing lugs  236  on shaft  234 . 
   It is further noted that the opening in the top of connector  227  has opposing recesses  242  that are configured to allow free passage of the connector lugs  236  when connector  223  is rotated 90 degrees to align lugs  236  with recesses  242  when the package is unlocked, in a manner to be described. 
   Package  213  is used as follows. After articles of commerce are placed in cavity  224 , the card  219  is positioned over the cavity with the circular card openings  220  embracing the cylindrical walls  228  of the connectors  227 . Next the retainer connector elements  223  are aligned with blister elements  227  and then pressed downwardly to cause the lugs  236  to resiliently deform the flaps  240  which then snap into locking engagement with the top edges of the lugs  236  upon full insertion of shaft  234 .  FIGS. 14 and 15  show package  213  in locked configuration. The bottom view of  FIG. 19  shows lugs  236  in locked engagement with the flaps  240 . 
   The package  213  can be unlocked and opened in an easy and safe manner as follows. 
   Referring to  FIGS. 15 and 16 , when cutting tool blades are inserted in space  240  of package  213 , cuts in the frame  218  along the notches  239  can be made to create free segments  218 ( a ). See  FIG. 17 . 
   Next, the segment  218 ( a ) is rotated through 90 degrees to the position shown in  FIG. 18 .  FIG. 20  shows how the lugs  236  are then aligned with the open portion  242  which allows segment  218 ( a ) to be moved upwardly, as indicated in  FIG. 18 . The remaining connectors are manipulated in a similar fashion to unlock and open the package. 
   While particular embodiments of the invention have been shown, it is not intended that the invention be limited thereto. Various modifications and variations of the invention will be evident to persons of ordinary skill in the art, given the benefit of this disclosure, and it is intended that the invention be given its full scope and breath as defined in the claims that follow.