Abstract:
Methods of forming a thermoformed recloseable flat package for a pill-like product are provided. A first enclosure portion having a closing member is first operably engaged with a second enclosure portion so as to form an enclosure for containing the product therein. One or more components of a locking mechanism are then formed, following formation of the enclosure, wherein the locking mechanism generally comprises a first component operably engaging the closing member and a cooperable second component operably engaging the second enclosure portion. The components of the locking mechanism are further configured to be separable so as to allow separation thereabout of the closing member from the second enclosure portion to thereby define the recloseable package capable of selectively allowing the product to be extracted from the enclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 60/214,506, filed Jun. 28, 2000 and U.S. Provisional Patent Application No. ______ entitled “Product Package With Thermoformed Locking Feature,” filed May 25, 2001, both of which are incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to product packages and, more particularly, to methods of forming a rigid package having a recloseable locking mechanism so as to allow the removal of consumable products, such as candy items, from the package.  
         BACKGROUND OF THE INVENTION  
         [0003]    In the packaging of various consumable products, such as candy items and the like, various package constructions have been proposed. For example, in the case of mints, which can be shaped as pills or tablets, various rigid and soft packages have been created that allow the opening and reclosing of the package so that the consumer can open and reclose the package to consume mints only when desired. Such packages include paper or foil rolls, tin cans having openable and closable lids and rigid plastic containers having hinged flaps that are molded to allow the flap to lock or snap shut when the package is closed.  
           [0004]    One type of package that has proven to be popular is a “credit card” type package for packaging small pill-shaped mints. These packages are formed of two injection molded halves of polystyrene or polypropylene snapped together to define a cavity for the mints. The two halves have plan dimensions that are approximately the same as conventional credit cards although when snapped together with mints therebetween, the package is somewhat thicker than a conventional credit card. Thus, the two halves are generally flat and when combined define a seam extending around the peripheral edge of the package. At one corner of one of the halves a hinge is provided so that a corner portion can be bent back and mints can be released from the package through the opening formed by the corner portion. The corner portion is provided with a recess on an inner surface that mates with a corresponding projection on the other half of the package. Accordingly, when closed, the recess of the corner portion interlocks with the projection of the opposing half to prevent inadvertent opening of the package, such as may occur with other package types when placed in a purse or pocket of the consumer. The credit card-type packages can hold, for example, 50 mints and can be opened and closed a corresponding number of times to allow dispensing of individual mints.  
           [0005]    When packaged by the manufacturer, the credit card-type packages are overwrapped with a plastic film wrapper, such as a polyester, polypropylene or cellophane film. The film wrapper serves two purposes. First, the film wrapper provides a moisture barrier to prevent moisture from contaminating the mints packaged therein. Although fitting together closely, the two molded halves of the package do not by themselves form a hermetic seal. Accordingly, the film wrapper provides a moisture barrier which prevents moisture, such as humidity in tropical climates, from permeating to the mints during shipping and while stored or displayed at the point of purchase. The consumer first peels away the film wrapper, which may be provided with a tear strip, and then bends back the corner portion of one of the molded halves of the package.  
           [0006]    A second purpose of the plastic wrapper is to provide tamper-evident protection. To prevent tampering with the mints during the shipping, storage and display stages of the retail process, the film wrapper provides visible evidence in the event an attempt is made to tamper with the product. The consumer can easily determine whether the package has been previously opened, or an attempt has been made to open the package, by visually inspecting the integrity of the film wrapper. Conventional credit card-type packages have several disadvantages. First, the injection molding process for forming the halves of the package is relatively expensive and involves the tooling costs and cycle times associated with injection molding processes. In addition, the halves are often assembled by hand which entails the attendant labor costs and assembly times normally associated with manual labor.  
           [0007]    Another manufacturing technique that has been used in connection with other packages, such as blister packages for pharmaceuticals, involves thermoforming a thermoplastic web of material into a desired shape. A generally flat web of material is advanced through a thermoforming station which is provided with opposed dies having corresponding projections and depressions. The dies are closed and heat and pressure are applied to the web of material to plastically deform the material into the desired shape. Upon cooling, at least part of a package is formed, such as the blister portion of a conventional blister package. A foil lidstock is often then heat sealed to the blister portion to seal the package closed. The thermoforming process is relatively inexpensive and can provide high throughput.  
           [0008]    However, one disadvantage of thermoformed packages is that the packages generally cannot be opened and reclosed such that the package is locked when reclosed. For example, once the foil lidstock has been peeled back, it typically cannot be securely reclosed. Accordingly, there is a need in the industry for a package which achieves the benefits of thermoforming processes, namely lower cost and higher processing speeds, while at the same time providing the recloseable features of conventional injection molded packages wherein certain edges and surfaces of the molded pieces can be shaped to interlock when the package is closed.  
           [0009]    A further disadvantage of conventional credit card-type packages is the need to overwrap the package with a plastic wrapper. The wrapping of these packages involves an extra processing step during manufacture and also requires a corresponding unwrapping step on behalf of the consumer. Accordingly, it would be advantageous to provide a credit card type-package that retains both the moisture barrier and tamper-evident properties of conventional credit card-type packages but yet which does not require a separate plastic wrapper around the package. All of these desirable attributes are advantageously provided by the present invention as discussed further below.  
         SUMMARY OF THE INVENTION  
         [0010]    The above and other needs are met by the present invention which, in one embodiment, provides a method of forming a thermoformed recloseable flat package for a pill-like product. A first enclosure portion having a closing member is first operably engaged with a second enclosure portion so as to form an enclosure for containing the product therein. Each enclosure portion has a major surface such that the major surfaces of the respective enclosure portions are generally parallel when the first and second enclosure portions are operably engaged. A component of a locking mechanism is then formed, following formation of the enclosure. The locking mechanism generally comprises a first component operably engaging the closing member and a second component operably engaging the second enclosure portion. The first component corresponds to, and is configured to operably engage, the second component to secure the closing member to the second enclosure portion. The components of the locking mechanism are further configured to be separable so as to allow separation thereabout of the closing member from the second enclosure portion. A recloseable package capable of selectively allowing the product to be extracted from the enclosure is thereby defined.  
           [0011]    Another advantageous aspect of the present invention comprises a method of forming a thermoformed recloseable flat package for a pill-like product, wherein a first enclosure portion having a closing member is first operably engaged with a second enclosure portion defining at least one aperture component of a locking mechanism so as to form an enclosure for containing the product therein. Each enclosure portion has a major surface such that the major surfaces of the respective enclosure portions are generally parallel when the first and second enclosure portions are operably engaged. A projection component of the locking mechanism is then formed from the closing member, following formation of the enclosure. The projection component corresponds to, and is configured to operably engage, the at least one aperture component to secure the closing member to the second enclosure portion. The components of the locking mechanism are further configured to be separable so as to allow separation thereabout of the closing member from the second enclosure portion.  
           [0012]    Still another advantageous aspect of the present invention comprises a method of forming a thermoformed recloseable flat package for a pill-like product, wherein a first enclosure portion having a pivotable closing member is first operably engaged with a second enclosure portion defining at least one lip component of a locking mechanism so as to form an enclosure for containing the product therein. Each enclosure portion has a major surface such that the major surfaces of the respective enclosure portions are generally parallel when the first and second enclosure portions are operably engaged. A projection component of the locking mechanism is then formed from the closing member, following formation of the enclosure. The projection component corresponds to, and is configured to operably engage, the at least one lip component in an interference fit, with respect to pivoting of the closing member, to secure the closing member to the second enclosure portion. The projection component is further configured to be separable from the at least one lip component so as to allow separation thereabout of the closing member from the second package portion.  
           [0013]    Yet another advantageous aspect of the present invention comprises a method of forming a thermoformed recloseable flat package for a pill-like product, wherein a first package portion having a pivotable closing member is first operably engaged with a peripheral flange of a second package portion so as to form an enclosure for containing the product therein. Each enclosure portion has a major surface such that the major surfaces of the respective enclosure portions are generally parallel when the first and second enclosure portions are operably engaged. A portion of the peripheral flange corresponding to the closing member is then undercut so as to form opposing first and second components of a locking mechanism. The components of the locking mechanism are operably engageable and configured in an interference fit, with respect to pivoting of the closing member, to secure the closing member to the second enclosure portion. The first and second components are further configured to be separable to as to allow separation thereabout of the closing member from the second enclosure portion.  
           [0014]    Thus, embodiments of the present invention provide methods of forming a recloseable package for a product which achieve the benefits of thermoforming processes, namely lower cost and higher processing speeds, while at the same time provide the recloseable features of conventional injection molded packages wherein certain edges and surfaces of the molded pieces can be shaped to interlock when the package is closed. By forming the locking mechanism after assembly of the package, a high correspondence between the components of the locking mechanism may also be achieved. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds when taken in conjunction with the accompanying drawings, which are not necessarily drawn to scale, wherein;  
         [0016]    [0016]FIG. 1 is a perspective view of a package according to the present invention showing a corner portion thereof in an open position;  
         [0017]    [0017]FIG. 2 is a portion of FIG. 1 illustrating the corner portion in a closed position;  
         [0018]    [0018]FIG. 3 is a cross sectional view of a lower tray of the package;  
         [0019]    [0019]FIG. 4 is a cross sectional view like FIG. 3 illustrating the placement of consumable items therein;  
         [0020]    [0020]FIG. 5 is a cross sectional view like FIG. 4 illustrating the position of a foil layer over the consumable items;  
         [0021]    [0021]FIG. 6 is a cross sectional view like FIG. 5 illustrating the position of an opening formed through the foil layer and lower tray;  
         [0022]    [0022]FIG. 7 is an enlarged view of the encircled portion of FIG. 6;  
         [0023]    [0023]FIG. 8 is a view like FIG. 7 illustrating the position of a cover member;  
         [0024]    [0024]FIG. 9 is a view like FIG. 8 illustrating the thermoforming of a locking projection extending through the foil layer and a flange of the lower tray; and  
         [0025]    [0025]FIG. 10 is a view like FIG. 9 illustrating the locking projection after formation thereof.  
         [0026]    [0026]FIGS. 11A and 11B are perspective views of a package according to an alternate embodiment of the present invention showing a corner portion thereof in an open position and a closed position, respectively.  
         [0027]    [0027]FIG. 11C is a partial cross sectional view along line  11 C- 11 C of FIG. 11B illustrating the locking projection thereof.  
         [0028]    [0028]FIG. 11D is an enlarged partial side view of the encircled portion of FIG. 1I B.  
         [0029]    [0029]FIGS. 12A and 12B are perspective views of a package according to another alternate embodiment of the present invention showing a corner portion thereof in an open position and a closed position, respectively.  
         [0030]    [0030]FIG. 12C is a plan view of the package of FIG. 12A illustrating the corner portion thereof in a closed position.  
         [0031]    [0031]FIG. 12D is an enlarged partial side view of the encircled portion of FIG. 12B  
         [0032]    [0032]FIGS. 13A and 13B are perspective views of a package according to another alternate embodiment of the present invention showing a corner portion thereof in an open position and a closed position, respectively.  
         [0033]    [0033]FIG. 13C is a plan view of the package of FIG. 13A illustrating the corner portion thereof in a closed position.  
         [0034]    [0034]FIG. 13D is an enlarged partial side view of the encircled portion of FIG. 13B. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]    The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.  
         [0036]    [0036]FIG. 1 illustrates a package  10  according to the invention for packaging consumable items  11 . The term “consumable items” is intended to be broad and cover all types of items which may be packaged including mints and other candies, pharmaceutical products such as pills, tablets and the like and any other products of use to a consumer which can be packaged in packaging of the type discussed herein. When viewed in plan, the package  10  can have the approximate size of a conventional credit card although the thickness of the package can be somewhat larger than the thickness of a credit card. The package  10  is thus of a convenient size and shape for carrying items which may be intermittently consumed, such as mints.  
         [0037]    A corner portion  12  of the package  10  is shown in FIG. 1 in an open position, which allows removal of consumable items  11  from the package. Although not illustrated, the package  10  may be provided with one or more internal gates, passageways or channels that permit the dispensing of only one consumable item  11  at a time from the package  10 . The corner portion  12  includes a pair of locking projections  13  which, as discussed in more detail below, lock the corner portion  12  in a closed position. The locking projections  13  are received and engaged by corresponding openings  14  in the lower tray  15  of the package  10 . The corner portion  12  is shown in a closed position in FIG. 2 such that only the upper sides of the locking projections  13  are visible.  
         [0038]    The formation of the package  10  according to the present invention is illustrated in FIGS.  3 - 10 . FIG. 3 illustrates the configuration of the lower tray  15 . The lower tray  15  is formed by thermoforming a sheet or web of thermoformable material such as polyvinylchloride (PVC). The sheet can have a thickness of 20-25 mils, which results in a relatively rigid lower tray  15 . The sheet of thermoformable material is advanced continuously or indexed into a thermoformer that has corresponding projections and depressions in a matching pair of forming dies, as would be understood by one of ordinary skill in the art. For example, for the lower tray  15  illustrated in FIG. 3, the upper forming die may include a projection having a shape corresponding to the upper surface of the lower tray  15  and the lower forming die may have a corresponding depression corresponding to the lower surface of the lower tray  15 . As would be further understood by one of ordinary skill in the art, the sheet of thermoformable material may include multiple rows and columns of blanks each corresponding to an individual lower tray  15 . At some subsequent point in the manufacturing process, such as after the packages have been filled and sealed, a cutting die or other sharp member can be used to cut the sheet between the blanks to form individual packages. The lower tray  15  includes a peripheral flange  16  which extends around the periphery of the lower tray  15 . The peripheral flange  16  can be wider at portions underlying the corner portion  12  to more readily accommodate the openings  14 .  
         [0039]    After the formation of the lower tray  15 , the tray  15  is filled with consumable items  11 , as shown in FIG. 4. As one example, the tray  15  may be filled with fifty (50) small mints.  
         [0040]    After the consumable items  11  have been placed in the lower tray  15 , an aluminum foil layer  17  is applied over the lower tray, as shown in FIG. 5. Specifically, the foil layer  17  is heat-sealed at its peripheral edges to the peripheral flange  16  of the lower tray  15 . In this fashion, the consumable items  11  are hermetically sealed within the space defined by the lower tray  15  and the foil layer  17 . This hermetic seal is broken when the consumer first opens the package  10 , as discussed in more detail below. The use of the foil layer  17  provides a convenient moisture barrier and tamper-evident function which eliminates the need for a plastic wrapper covering the entire package of the type used in prior credit card-type packages. Although referred to as a foil layer  17 , it will be understood that any suitable material could be used having appropriate barrier properties and/or tamper-evident indication capabilities. One example of an alternative material is polyester film.  
         [0041]    One or more openings  14  are then formed through the foil layer  17  and the peripheral flange  16  of the lower tray  15 , as shown in FIG. 6. Only one opening  14  is illustrated in more detail in FIG. 7, although it is to be understood that one or more openings can be used. For example, as shown in FIG. 1, two openings  14  are used for locking the corner portion  12  to the peripheral flange  16  of the lower tray  15 . The openings  14  can be formed in any conventional way including die punching and the like, provided that the resulting opening has relatively well-defined edges for securely retaining the locking projections  13 . In addition, the shape of the openings is not necessarily circular as illustrated. Circular openings may have a diameter of approximately 2 mm. A cover member  20  is then placed over the foil layer  17 . The cover member  20 , which may be formed of the same material as the lower tray  15 , is sealed to the upper surface of the foil layer  17 . A lacquer applied to the lower surface of the cover member  20  or an adhesive separately applied is heated during the sealing operation to seal the cover member  20  to the foil layer  17 . The distal edge of the cover member  20  may extend beyond the distal edge of the peripheral flange  16  by a small distance. The purpose for the slight overhang of the cover member  20  is to assist in opening of the corner portion  12 , as discussed in more detail below.  
         [0042]    The structure illustrated in FIG. 8 is then advanced into a thermoforming station comprising an upper die  21  and a lower die  22 . The upper die  21  is heated and defines an opening above the opening  14  in the foil layer  17  and lower tray  15 . The lower die  22  defines a cavity which is sized at its top edge slightly larger than the opening  14  extending through the lower tray  15 . In one embodiment, the cavity can be tapered as shown at a 60° angle and define an upper opening that has a diameter approximately 0.015 inches larger than the diameter of the opening  14 . The cavity can be approximately 2 mm deep. Air is pressurized through the opening in the upper die  21  in the direction of the arrow. The heat from the upper die  21  heats the thermoplastic material of the cover member  20  and the air forces the material through the opening  14  and into the cavity of the lower die  22 . If necessary, a die member, which may be heated, can be pushed into the opening to create a “plug assist” for helping to move the molten material into the opening  14 . The lower die  22  is cooled and the molten polymer of the cover member material is cooled and solidified in the shape of the cavity, as shown in FIG. 9. If desired, the step of sealing the cover member  20  to the foil layer  17  can also be performed contemporaneously by the upper and lower dies  21 ,  22 . The upper and lower dies  21 ,  22  are then withdrawn and the resultant finished structure is illustrated in FIG. 10.  
         [0043]    The package  10  is then shipped to the consumer and the consumable items  11  are hermetically sealed within the cavity defined by the foil layer  17  and the lower tray  15 .  
         [0044]    When the consumer purchases the package  10  and endeavors to open the package  10 , the consumer first engages the distal edge of the foil layer  17  and/or cover member  20  at the corner portion  12 . The overhanging portion of the cover member  20  is a signal to the consumer not to attempt to delaminate the cover member  20  from the lower tray  15  by inserting a fingernail or other sharp member between the cover member  20  and the lower tray  15 .  
         [0045]    A pair of cuts  23  are formed through the cover member  20 , foil layer  17  and peripheral flange  16  between the corner portion  12  and the remainder of the package  10 . Also, a score line  24  is formed between the cuts  23  as can be seen in FIG. 2. When the package  10  is opened and the corner portion  12  is lifted the corner portion  12  is folded along the cuts  23  and score line  24  to define a hinge as well as a generally triangular shaped corner portion. After a consumable item  11  is removed, the corner portion  12  is folded back along the cuts  23  and score line  24  to close the package  10 . Specifically, the locking projections  13  of the cover member  20  are inserted back into the openings  14  in the peripheral flange  16  of the lower tray  15 . Because of the shape of the locking projections  13  formed during the thermoforming process, the locking projections  13  engage the openings  14  in a snap fit and lock the corner portion  12  in the closed position. Thus, the thermoformed locking projections  13  form a secure interlocking fit without the need for expensive injection molded profiles of interlocking projections. In addition, manufacturing speeds of up to 400 packages per minute can be achieved.  
         [0046]    Another advantageous feature of the present invention is that the foil layer  17  provides a tamper-evident function. When the corner portion  12  is opened, the foil layer  17  may remain adhered to the peripheral flange  16 . An intact foil layer  17  signals to the consumer that the package  10  has not been tampered with and the foil layer  17  can then be punctured to gain access to the consumable items  11 .  
         [0047]    In addition, the condition of the hinge indicates to the consumer whether the package  10  has been previously opened. The hinge appearance will change when opened and may, for example, appear slightly cracked. Thus, if the foil layer  17  remains adhered to the cover member  20  when the corner portion  12  is opened, the absence of any tampering is indicated by the hinge. The heat sealing head that seals the cover member  20  to the foil layer  17  may be knurled to encourage the foil layer  17  to remain adhered to the cover member  20  when the package  10  is opened. If an extra level of tamper-evident protection is desired, the package  10  can also be wrapped with a film wrapper or a frangible band around the corner portion  12 .  
         [0048]    [0048]FIGS. 11A and 11B illustrate an alternate embodiment of a package  10  according to the present invention. This alternate embodiment eliminates the foil layer  17 , as previously discussed herein, such that the cover member  20  is directly sealed to the lower tray  15 , such as by thermal bonding. However, even though the foil layer  17  is not present, the package  10  according to this embodiment is configured to provide tamper-evident features as discussed in more detail below. As shown in FIG. 11A, the lower tray  15  may include a pair of flange projections  16   a  extending inwardly from the peripheral flange  16  so as to form a passageway  25  therebetween. The passageway  25  allows removal of the consumable items  11  from the package  10 . The corner portion  12  includes a pair of locking projections  13  for locking the corner portion  12  in a closed position. The locking projections  13  are received and engaged by corresponding openings  14  in the respective flange projections  16   a  of the lower tray  15 . An advantage of this alternate embodiment is that the width of the peripheral flange  16  may be reduced since the flange projections  16   a  accommodate the openings  14 . Accordingly, less material may be required to form the lower tray  15  and/or the capacity of the package  10  may be increased without increasing the outer dimensions thereof.  
         [0049]    The corner portion  12  is shown in a closed position in FIG. 11B such that only the upper sides of the locking projections  13  are visible. To define the corner portion  12 , a pair of cuts  23  are formed that extend through the peripheral flange  16  and, in some instances, may partially extend into the cover member  20 . Thus, one corner of the package  10  defines one point of the triangular corner portion  12 , while the cuts  23  define the remaining two points of the corner portion  12 . In some instances, the cuts  23  are angled toward each other so as to define a straight line  27 . The cuts  23  are shown from a plan view in FIG. 11B and from a side view in FIG. 11D corresponding to the circled area labeled  11 D in FIG. 11B. The cuts  23  may be formed with, for example, a knife or a steel rule and die. In some instances, the cuts  23  may be angled with respect to the vertical plane.  
         [0050]    As such, when the package  10  is opened by lifting the corner portion  12 , the cuts  23  cause the corner portion  12  to folded along a line  27  between the cuts  23  so as to form a hinge and define a generally triangular shaped corner portion. The locking projections  13  of the cover member  20  are also withdrawn from the openings  14  in the projections  16   a . In some instances, an adhesive seal between the corner portion  12  and the corresponding portion of the peripheral flange  16  may also be broken when the package  10  is opened. Folding the corner portion  12  along the line  27  causes deformation of the material comprising the package  10  along the line  27  comprising the hinge. The deformation of the material is preferably visible to the consumer, such as, for example, where the material changes color when deformed. Accordingly, visible deformation of the corner portion  12  about the line  27  would comprise, for instance, a tamper-evident indicator for the consumer. In some instances, the folding of the corner portion  12  may be facilitated by appropriately scoring along the hinge area on the side of the cover member  20  facing the lower tray  15  such that the scored area is not readily apparent until the corner portion  12  is opened. After a consumable item  11  is removed, the corner portion  12  is folded back along the line  27  to close the package  10  by inserting the locking projections  13  of the cover member  20  into the openings  14  in the projections  16   a  of the lower tray  15  in a snap fit, as shown in FIG. 11C.  
         [0051]    [0051]FIGS. 12A and 12B illustrate another alternate embodiment of a package  10 , according to the present invention, having the foil layer  17  eliminated such that the cover member  20  is directly sealed to the lower tray  15 . However, even though the foil layer  17  is not present, the package  10  according to this embodiment is configured to provide tamper-evident features as discussed in more detail below. As shown in FIG. 12A, the lower tray  15  also includes a pair of flange projections  16   a  extending inwardly from the peripheral flange  16  so as to form a passageway  25  for allowing removal of the consumable items  11  from the package  10 . The corner portion  12  includes a locking projection  13  for locking the corner portion  12  in a closed position, wherein the locking projection  13  is received and engaged by the passageway  25  defined by the flange projections  16   a  of the lower tray  15 . An advantage of this alternate embodiment is that the width of the peripheral flange  16  or, in some instances, the flange projections  16   a , may be further reduced since the passageway  25  engages the locking projection  13  and no additional corresponding opening is required therefor. Accordingly, less material may be required to form the lower tray  15  and/or the capacity of the package  10  may be additionally increased without increasing the outer dimensions thereof. Note that, in some instances not including the flange extensions  16   a , the inner edge of the peripheral flange  16  may be sufficient for interacting with the locking projection  13 , in an interference fit, to lock the corner portion  12  in a closed position.  
         [0052]    The corner portion  12  is shown in a closed position in FIG. 12B such that only the upper side of the locking projection  13  is visible. In a commercial embodiment, the upper side of the locking projection  13  may be covered by an adhesive label or the like to improve the aesthetic appearance of the package. Further, in order to define the corner portion  12 , a pair of cuts  23  are formed that extend through the peripheral flange  16  and, in some instances, may partially extend into the cover member  20 . Thus, one corner of the package  10  defines one point of the triangular corner portion  12 , while the cuts  23  define the remaining two points of the corner portion  12 . In some instances, the cuts  23  are angled toward each other so as to define a straight line  27 . The cuts  23  are shown from a plan view in FIG. 12B and from a side view in FIG. 12D corresponding to the circled area labeled  12 D in FIG. 12B. The cuts  23  may be formed with, for example, a knife or a steel rule and die. In some instances, the cuts  23  may be angled with respect to the vertical plane.  
         [0053]    As such, when the package  10  is opened by lifting the corner portion  12 , the cuts  23  cause the corner portion  12  to folded along a line  27  between the cuts  23  so as to form a hinge and define a generally triangular shaped corner portion. The locking projection  13  of the cover member  20  is also withdrawn from the passageway  25 . In some instances, an adhesive seal between the corner portion  12  and the corresponding portion of the peripheral flange  16  may also be broken when the package  10  is opened. Folding the corner portion  12  along the line  27  causes deformation of the material comprising the package  10  along the line  27  comprising the hinge. The deformation of the material is preferably visible to the consumer, such as, for example, where the material changes color when deformed. Accordingly, visible deformation of the corner portion  12  about the line  27  would comprise, for instance, a tamper-evident indicator for the consumer. In some instances, the folding of the corner portion  12  may be facilitated by appropriately scoring along the hinge area on the side of the cover member  20  facing the lower tray  15  such that the scored area is not readily apparent until the corner portion  12  is opened. After a consumable item  11  is removed, the corner portion  12  is folded back along the line  27  to close the package  10  by inserting the locking projection  13  of the cover member  20  into the passageway  25  of the lower tray  15 . The close proximity of the locking projection  13  to the flange projections  16   a  defining the passageway  25  causes the locking projection  13  to engage the passageway  25  in a snap or interference fit, as shown in FIG. 12C, to lock the corner portion  12  in a closed position. Note that, for example, the cover member  20  could be formed separately from the lower tray  15  and the locking projection  13  could be provided with an undercut profile so as to enhance the locking effect with flange projections  16   a  having complementary shapes.  
         [0054]    [0054]FIGS. 13A and 13B illustrate yet another alternate embodiment of a package  10  according to the present invention. This embodiment also eliminates the foil layer  17 , as previously discussed herein, such that cover member  20  is directly sealed to the lower tray  15 . Even so, the package  10  is configured to provide tamper-evident features as described in more detail below. As shown in FIG. 13A, the corner portion  12  includes lip  26  for locking the corner portion  12  in a closed position, wherein the lip  26  is engaged by a portion of the peripheral flange  16  of the lower tray  15 . An advantage of this alternate embodiment is that the width of the peripheral flange  16  may be configured to be minimal since interlocking locking projections  13  and corresponding openings  14  are not required. Accordingly, less material may be required to form the lower tray  15  and/or the capacity of the package  10  may be additionally increased without increasing the outer dimensions thereof. Such a configuration may also provide a less restricted opening through which the consumable items  11  are extracted from the package  10 .  
         [0055]    The corner portion  12  is shown in a closed position in FIG. 13B. As shown, the lip  26  extends along the periphery of the corner portion  12  about the corner of the package  10 . The lip  26  is terminated at each end thereof by a cut  23  extending through the peripheral flange  16  to the cover member  20 . Preferably, the cut  23  is angled with respect to the vertical plane so as to extend into the peripheral flange  16  at an angle directed away from the folding line  27  along which the corner portion  12  is folded when the package  10  is opened, as shown in FIG. 13D and corresponding to the encircled area of FIG. 13B labeled  13 D. The cuts  23  thereby form a locking mechanism between the lip  26  and the peripheral flange  16  that will be described below in further detail. In some instances, the lip  26  comprises a portion of the peripheral flange  16 . More particularly, the cover member  20  is first sealed to the lower tray  15  according to a process as previously described. Subsequently, the package  10  is subjected to a perforation process whereby the cuts  23  are formed through the peripheral flange  16 . In addition, further to or concurrently with the formation of the cuts  23 , the inner ends of the cuts  23  are joined by a joining cut  29  through the peripheral flange  16  and spaced apart from and corresponding to the periphery of the edges of the corner portion  12 . The joining cut  29  may extend through the peripheral flange  16  in the vertical plane or, in some instances, may be angled away from the folding line  27  as the joining cut  29  proceeds through the peripheral flange  16  toward the cover member  20 , as shown in FIG. 13C. The cuts  23  and joining cut  29  may be formed with, for example, a knife or a steel rule and die.  
         [0056]    In some instances, the folding of the corner portion  12  may be facilitated by appropriately scoring along the hinge area on the side of the cover member  20  facing the lower tray  15 , before the cover member  20  is sealed to the lower tray  15 , such that the scored area is not readily apparent until the corner portion  12  is opened. Further, as shown in FIGS. 13A and 13B, the cuts  23  defining the termination of the lip  26  may be spaced apart from the folding line  27  though, according to various embodiments of the invention, the cuts  23  may be disposed at any point along the corresponding edges of the corner portion  12  so as to define a lip  26  with varying dimensions.  
         [0057]    As shown in FIGS. 13C and 13D, the angled cuts  23  and/or joining cut  29  results in an underlying edge  28   a  on the lip  26  generally opposing an overhanging edge  28   b  on the corresponding portion of the peripheral flange  16  in an interference fit. As the corner portion  12  is opened by lifting the lip  26 , in the direction of the dashed arrow  30  as shown in FIG. 13D, the underlying edge  28   a  must be forced past the overhanging edge  28   b . As such, the interaction of the underlying edge  28   a  and the overhanging edge  28   b  comprises a locking mechanism as the corner portion  12  of the package  10  is opened and closed. Note that, in other instances, the angled cuts  23  may be formed in a variety of orientations with respect to the direction of each angled cut  23  and will provide a similar function as long as the peripheral flange  16  includes the overhanging edge  28   b.    
         [0058]    Further, in some instances, an adhesive seal between the corner portion  12  and the corresponding portion of the peripheral flange  16  may also be broken when the package  10  is opened. Also, folding the corner portion  12  along the line  27  may cause deformation of the material comprising the package  10  along the line  27  comprising the hinge. The deformation of the material is preferably visible to the consumer, such as, for example, where the material changes color when deformed. Accordingly, visible deformation of the corner portion  12  about the line  27  would comprise, for instance, a tamper-evident indicator for the consumer.  
         [0059]    After a consumable item  11  is removed, the corner portion  12  is folded back along folding line  27  to close the package  10  by urging the underlying edge  28   a  of the lip  26  over the overhanging edge  28   b  of the peripheral flange  16 . The close proximity of the underlying edge  28   a  to the overhanging edge  28   b  causes a snap or interference fit engagement, as shown in FIGS. 13C and 13D, when locking the corner portion  12  in a closed position.  
         [0060]    Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. For example, conventional blister packages could be improved by fastening a cover member over the lid stock by way of multiple locking projections extending into flange portions of the blister web material. Thus, the cover member must be first removed before pharmaceuticals can be punched through the lidstock, thereby providing additional resistance to opening by children. Another example would be eliminating any lacquer or adhesive used to adhere the cover member to the foil layer and providing one or more locking projections across the width of the package that are engaged in blisters formed upwardly from the lower tray and having openings formed therein, thereby mechanically interlocking the lower tray and the cover member. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.