Tamper-Resistant Bottle Cap

The gist of this invention is to provide a bottle cap of one-piece molded construction which, at the point of attachment to the bottle, engages both the inside and outside of the bottle opening in such a manner as to render the closure extremely difficult to pry off and provides a positive seal against the possibility of leaking of the bottle contents. This is accomplished by providing the closure with a double collar comprising inner and outer rings, the inner of which frictionally engages the inside of the bottle opening and the outer of which attaches to the outside of the bottle opening, the outer collar being constructed with a pull tab arranged so that when the contents of the bottle are to be used, pulling the pull tab peripherally of the bottle opening will tear away the outer collar of the cap and free the cap for "twist-off" removal from the bottle.

It is intended that the bottle be filled after the molded cap has been applied and for that purpose, the top of the cap is formed with an opening providing access to the interior of the bottle, the opening having an inwardly-extending extending collar which includes a molded circumferential locking and sealing ring on its inner wall adapted to engage a closure plug which, in turn, has a mating ring molded on it so that when the plug is snapped into the opening, it cannot be pulled out.

In one form of the invention, the closure plug is integral on and carried by an outwardly-extending tongue integral with the cap and so disposed that by bending the tongue over onto the top of the cap, the plug can be inserted in the filler opening to seal the same. In this arrangement, the closing tongue is fitted to the surface of the cap in such a manner as to make it difficult to insert a knife or any sharp object to pry the closure plug open. In another form of the invention, the closure plug is a separate element which, when inserted into the well in the bottle cap, becomes permanently locked in place with its top end fitted to the top surface of the cap in such a manner as to serve to prevent the plug being pried out. In another form of the invention, the inwardly-extending collar located on the top of the cap is closed off at the bottom of said collar by a bottom wall adapted for filling the bottle by means of a hollow needle inserted through said bottom.

Specific embodiments of this invention are shown in the accompanying drawings, in which:

FIG. 1 is a partly sectioned view showing the bottle and closure cap combination with the cap locked and sealed to the bottle;

FIG. 2 is a top view of the closure cap when applied to the bottle in closing relation;

FIG. 3 is a sectional view through the bottle cap and the upper end of the bottle as taken on line 3--3 of FIG. 2;

FIG. 4 is a top plan view of the closure cap before use;

FIG. 5 is a sectional view of the same as taken on line 5--5 of FIG. 4;

FIG. 6 is a sectional view as taken on line 6--6 of FIG. 2;

FIG. 7 is a partly sectioned view showing a modified form of the closure cap;

FIG. 8 is a top plan view of the same;

FIG. 9 is an elevational view of the closure plug used in the modified form of closure cap; and

FIG. 10 is a sectional view of a further modification of the closure cap with the closure plug removed and showing a transverse wall across the bottom of the filler opening adapted for filling the bottle by means of a hollow needle.

As shown in FIGS. 1 to 6, inclusive, the improved bottle cap 10 is a molded construction adapted to be fitted onto the open end of a conventional cylindrical bottle 11 and secured thereto by engagement with an annular bead or catch 12 integral on the said bottle at its open end. In the form shown, the improved closure cap comprises a top wall or platform 14 having a peripheral upstanding collar 16 and a pair of depending radially-spaced collars 18 and 20 which are adapted to receive between them the open end of the cylindrical bottle 11.

A particular feature of this improved bottle cap resides in the inner collar 20 being made slightly greater in its external diameter than the inside diameter of the bottle 11, for example about two thousandths of an inch, whereby the collar 20 will be in tight frictional engagement with the inner surface of the bottle 11 when the cap is applied thereto. The external or outer depending collar 18 is also proportioned to closely fit the external surface of the open end of the bottle 11 and is provided with a latch 22 adapted to engage beneath the catch 12 on the bottle 11. With this arrangement, when the cap 10 is applied to the bottle 11, it becomes securely fixed thereto, so that it cannot be pulled or pried away from the open end of the bottle and can only be removed by breaking away the depending outer collar 18 in its entirety by the use of pull tab 42.

In the form shown, the platform 14 of the improved bottle cap is provided with an annular opening 24 which is surrounded by a depending cylindrical wall 26 which, on its inner surface, is provided with a latching groove 28 adapted to be engaged by a peripheral external catch 30 formed on the outer surface of a closure plug 32.

With this arrangement of cap opening 24 and closure plug 32, the bottle 11 can be filled and sealed after the molded closure cap 10 has been applied to the open end of the bottle and once the closure plug 32 has been forced into the filler opening 24 of the bottle cap, the bottle becomes firmly sealed and its contents is secure against tampering of any kind.

In the form of the improved bottle cap shown in FIGS. 1 to 6, inclusive, the closure plug 32 for the filler opening 24 is normally part of and carried by an outwardly-projecting tongue 34 which extends from the platform 14 or cap top as an integral part thereof, the tongue 34 being foldable about its juncture 35 with the platform 14 so as to closely overlie the upper surface of the platform 14 and present the plug 32 to the opening 24 whereby the plug 32 can be forced into the opening 24 to firmly seal the same. To facilitate this very close folding of the tongue 34 against the upper surface of the platform 14, the under side of the tongue 34 at the platform connection 35 is formed with a groove 36 which has a depth of substantially half the thickness of the tongue 34. This is clearly shown in FIG. 5.

As shown in FIGS. 1 to 6 and to secure the closure plug 32 against being pried out of the opening 24, a pair of upwardly-projecting ribs 38 and 40 are provided on the platform or cap top 14, equally spaced on each side of the opening 24, for reception of the tongue 34 between them when the tongue is folded over onto the upper surface of the cap top. The height of the ribs 38 and 40 is substantially the same as the thickness of the tongue 34 and the two ribs are spaced apart a distance of about four hundreths of an inch, or less, greater than the width of the tongue 34 so as to inhibit the introduction of a knife blade under the tongue 34 adjacent the plug 32 for the purpose of prying the plug out of the filler opening 24. Also, for the same purpose, the length of the tongue 34 is made so as to extend beyond the plug 32 to substantially reach the inner surface of the upstanding collar 16 as shown in FIG. 3.

For removal of the improved cap from the bottle 11, it is necessary to tear away the latching ring 18 at the lower portion of the cap 10 and to facilitate this action, the depending peripheral collar 18 is arranged to form a substantially complete circle with one side terminating immediately adjacent to a pull tab 42 which is formed at the other end of the collar 18 whereby the collar 18 can be broken away from the platform 14 and torn away peripherally to free the cap 10 from the bead or catch 12. This frees the cap 10 for a relatively easy twist-off removal from the bottle 11 against the friction of the tight engagement of the inner depending collar 20 with the inner surface of the bottle 11. To facilitate this twist-off removal of the cap 10 from the bottle 11, the periphery of the upstanding collar 16 of the cap 10 is knurled to provide a firm gripping surface, as indicated at 44 in FIG. 2.

The modified form of the improved bottle cap shown in FIGS. 7 to 9, inclusive, is of substantially the same construction as that shown in FIGS. 1 to 6 except that the tongue and closure plug carried thereby have been entirely omitted and the filler opening 24 has been located in the center of the cap top or platform 14. In this form of the device, the closure plug 46 is a separate and independent element and is provided with a head 48 to seat on the margin of the filler opening 24. Also, the depending collar or wall 50 of the filler opening 24 is provided with a catch 52 for a latching rib 54 on the plug 46 so that once the plug has been inserted in the filler opening, it becomes securely locked in place. To prevent the plug 46 from being surreptitiously pried out of the filler opening, the margin of the opening is surrounded by an upstanding rim or bead 56 of the same height as the thickness of the head 48 of the closure plug 46, the inside diameter of the rim 56 being substantially the same as the outside diameter of the head 48. In this form of the device, the removal of the modified bottle cap from the bottle 11 is performed in substantially the same manner as originally stated. The depending peripheral collar 18 is torn away peripherally to free the cap 10 from the bead or catch 12 by the use of the pull tab 42. The periphery of the upstanding collar 16 of the cap 10 is knurled to provide a firm gripping surface as indicated in FIG. 8.

In the form of the bottle cap shown in FIGS. 1 to 8, the filler openings 24 and their respective internal collars 26 and 50 are open from end-to-end for easy filling. In some cases, however, it may be desirable to fill the bottle or receptacle with a fluid best introduced by means of a hollow needle and for that purpose, the bottom end of the inner walls 26 and 50 may be closed off by a transverse wall 58, as shown in FIG. 10, which is relatively thin, for example, about twelve thousandths of an inch thick, and in the center of this wall, a groove is formed with a depth about three-quarters of the wall thickness. It is at this point that a needle can be punctured through the wall 58 to effect filling of the receptacle in a substantially self-closing needle puncture.

From the foregoing, it will be seen that there is provided a fully tamper-resistant closure cap for a conventional form of receptacle or bottle so that once the receptacle has been filled, its contents are safe and secure against contamination or surreptitious removal. Generally, the bottles or receptacles are made of a suitable plastic material and it is intended that the improved closure caps are to be molded from a plastic material that is to be substantially rigid when formed and for that purpose, it is suggested that the improved closure caps be molded from high density polyethylene material.

Although several embodiments of this invention have been herein shown and described, it will be understood that details of the constructions shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.