Push and Peel Blister Strip Packages

Containers or packages for medicaments are desirably easily openable by adults but not by children. There have been many attempts to provide such packages in blister form, but in some cases they are difficult to open even by an adult. It is the general purpose of the present invention to provide a package which is easily openable by one having knowledge of the opening procedure but which is difficult to open by a small child unfamiliar with the procedure.

British Pat. No. 577,151, published May 7, 1946, describes blister packages having dummy pockets which can be "easily broken thereby enabling a finger nail to be inserted between the two interadhered webs" for pulling apart a covering layer from a second blister-containing layer for easy access to the blisters in the latter. However this patent does not suggest specific unsealed areas for the purposes described herein.

The blister packages contempated by the present invention are particularly useful in the packaging of medicaments such as capsules, tablets and the like. Since the packages of the invention require certain opening manipulations which would thwart opening by small children, they are particularly useful in the field of child resistant strip packaging. The packages of the invention comprise two heat-sealed sheets, one of which is shaped, for example by thermoforming, so as to provide a first cavity or row of cavities intended to contain a product to be dispensed, for example capsules, tablets, etc., the other of which serves as a covering sheet to cover the former. Spaced from each first cavity or row of cavities in the cavity bearing sheet is a second cavity or row of second cavities equal in number to, and directly opposed to, the first cavity or row of cavities. The second cavities can be pushed inwards and inverted to disrupt the covering sheet from the cavity bearing sheet thus providing a pull tab which may be grasped and pulled towards the aligned pair of second and first cavities in order to peel off the covering sheet and provide access to the product dispensing cavities along predetermined weakened lines.

The package is also provided with perforations between individual pairs of first and second cavities and extending through both sheets which permit tearing off one product dispensing unit at a time.

FIG. 1 is a view illustrating the invention;

FIG. 2 is a section on line 2--2 of FIG. 1;

FIG. 3 is a view similar to FIG. 2, illustrating the inverted second cavity and the pull tab which is produced by the inversion;

FIG. 4 is a view illustrating a modifiction of the embodiment shown in FIG. 1;

FIG. 5 is a view of a single unit of the modification of FIG. 4 as viewed from the bottom; and

FIG. 6 is a section on line 6--6 of FIG. 5.

A sheet of heat sealable material, for example plastic, is indicated at 10 which underlies a second sheet 14, which is heat sealed to the latter as indicated by the shading in FIG. 1. The underlying sheet contains a first cavity or row of cavities 12, produced for example by thermoforming and intended to contain a product for dispensing, for example tablets, capsules and the like. The underlying or cavity bearing sheet is overlayed by a covering sheet 14 which keeps the contents of the first cavities in pristine condition. It will be seen that the two sheets are heat sealed completely about each cavity. The underlying or cavity bearing sheet desirably should be relatively stiff in contrast to the covering sheet which desirably should be somewhat pliable. The desired degrees of stiffness in the two sheets can thus be achieved by use of thicker material in the cavity bearing sheet than that used in the covering sheet.

Laterally aligned with each first cavity in the cavity bearing sheet and spaced therefrom is a corresponding second cavity or row of cavities 18 which, like the first cavities, are covered by the covering sheet 14, the covered area of the second cavities being represented by the area 16 in FIG. 1. In the manipulation of this embodiment to provide access to any individual first cavity, it is merely necessary to depress a second cavity 18, which is laterally aligned with a particular first cavity to which access is desired, in the direction indicated by the arrow in FIGS. 2 and 3, thereby inverting the second cavity as shown in FIG. 3. This action will disrupt the covering sheet 14 in the area at 16 along the line represented by 20 thus forming a pull tab 22 which can be grasped between the forefinger and thumb and peeled back towards first cavity 12 thereby disrupting the heat sealed areas at 24 between the first and second cavities 12 and 18 and exposing the contents of the first cavity.

The lines 20 and 26 represent weakened lines in the covering sheet defining the three side edges of the second cavities which are non-adjacent to the first cavities, the weakened lines being formed for example by perforation, scoring, slitting etc. in order to facilitate opening the blister package. Moreover disruption of the covering sheet along the weakened lines 20 and 26 on inversion of the second cavities 18 is facilitated by leaving unsealed the small areas 28 which are bounded by the lines 20 and 26 and the edges of the second cavities 18 non-adjacent the first cavities.

If desired the strip packages of the invention can be provided with perforations indicated at 30 which extend through both sheets 10 and 14 and which permit the separation of the strip into individual units.

FIG. 4 shows a single unit of a modified blister strip generally indicated by the reference numeral 31. It will be understood however that the embodiment depicted in FIG. 4 can be formed into a multiple unit strip similar to that shown in FIG. 1. In the embodiment shown in FIG. 4, an underlying, cavity bearing sheet 10' is thermoformed to contain a first cavity 12' for containing a product and a second cavity 18' laterally aligned with each first cavity and spaced therefrom. An overlying covering sheet 14' covers the first and second cavities 12' and 18' and is heat sealed to the cavity bearing sheet in the areas surrounding the cavities as indicated by the shading.

The covering sheet 14' is provided with weakened lines 36 and 38 shown in FIGS. 4 and 5. Weakened line 36 comprises a generally arcuate portion located within the area described by second cavity 18' and connected at its two ends with weakened lines 38 which comprise side portions extending at an oblique angle from opposite sides of the arcuate portion of the side edges of the unit and directed generally towards the first cavities.

In the manipulation of the unit 31 to provide access to any given first cavity 12', a corresponding laterally aligned second cavity 18' is depressed as indicated by the arrow in FIG. 6 thus inverting the second cavity. This inversion disrupts the covering sheet 14' along the weakened arcuate line 36 thus forming a pull tab 40 which, as before, can be grasped and pulled back towards first cavity 12', the covering sheet being torn back along weakened side lines 38--38 which direct the peeling action towards the first cavity as the covering sheet is peeled off from the cavity bearing sheet 10'.

It will be appreciated from the foregoing that one not understanding the procedure required to effect rupture of the covering sheet permitting it to be peeled back to give access to the individual first cavities will not be able to open the package. Thus it will be seen that this invention also provides child resistant blister strip packages for medicaments.