US3285451A

US3285451A - Pressure closure

Info

Publication number: US3285451A
Application number: US440889A
Authority: US
Inventors: Golde Erich
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-11-12
Filing date: 1965-03-18
Publication date: 1966-11-15
Anticipated expiration: 1983-11-15
Also published as: CH453116A; NL6505277A

Description

Nov. 15, 1966 E. GOLDE PRESSURE CLOSURE Filed March 18, 1965 INVENTOR ERICH GOLDE ATTORNEY 3 United States Patent PRESSURE CLOSURE Erich Golde, Tattenkofener Strasse 4, Geretsried 8192, Upper Bavaria, Germany Filed Mar. 18, 1965, Ser. No. 440,889 Claims priority, application Germany, Nov. 12, 1964,

Claims. (Cl. 215-40) This invention relates to bottle closures and more particularly to bottle caps for use on bottles containing carbonated beverages or other liquids which give rise to substantial pressures within the bottles in which they are contained.

It is known to use closure caps made of resilient thermoplastic resins for use on bottles or jars having an outwardly projecting crown or bead at their mouth. Such closures normally comprise principally a substantially fiat main deck member to cover the mouth of a bottle and, downwardly depending from the periphery of the deck member, a skirt member which is provided with an inwardly projecting retention beadwhich is adapted to become locked under the bead of the bottle. It is difficult, however, to fabricate such closures so as to make them effective for use on bottles containing carbonated beverages. The carbon dioxide which is liberated at higher temperatures when the filled bottles are shaken while in transit results in a great increase-in internal pressure and thereby tends to pop the closure off the bottle. Caps are known which somewhat reduce the effect of this internal pressure by confining it to a smaller area of cap by means of acircular sealing extension which depends from an intermediate portion of the deck of the cap and is adapted to fit tightly against the inside wall of the bottle month. However, even in such cases it is difficult to protect the cap against the effects of increased internal pressure because the normal tolerance or variation of the external diameters of the bottle mouth places definite limits on the degree to which the wall thickness of the skirt and of the retention bead, or the stiffness of the resinous material, can be increased. This is particularly true when the closure is intended to be removable and replaceable by hand.

Furthermore, economic reasons make it desirable to avoid thick walls as these increase the quantity of material required and result in longer machine operating times during fabrication.

This is where the present invention makes its surprising contribution. According to this invention the peripheral portion of the upper surface or deck of the cap and its skirt are grooved or perforated by two or more narrow indentations or notches, preferably substantially opposite from each other, which end in the skirt approximately at the level of the retention bead, leaving the portion of the skirt below the retention bead substantially unweakened. Tests have shown that closures provided with such notches, grooves or perforations resist considerably higher internal pressures than caps of equal wall thickness which do not have such notches. An explanation of this effect will be given later in connection with the drawing.

The invention results in the further advantage in that the notches or perforations facilitate the removal of the cap from the bottle. To provide this additional advantage it is preferable to place the notches on a diameter of the cap which is perpendicular to the diameter on which the lift tab is attached to the cap. Furthermore, the described notches substantially assist in compensating for the tolerance in the external diameter of the mouth of the bottle.

The invention can likewise be used for closures which, instead of the aforementioned sealing extension, contain a separate sealing insert adapted to protrude into the mouth of the bottle. Such a two-component construction is particularly advantageous when the bottle is intended for opening by hand. In such a case it is possible to make the sealing insert from a softer resin than the cap itself and thereby facilitate placement and removal of such caps on bottles as well as compensation for any large tolerance in the inside wall of the bottle. It is particularly advantageous to equip such sealing inserts with a hollow seal ring. Furthermore, it is possible to attach such a sealing insert to the cap by fusion in the middle of the main deck of the cap and thereby facilitate the eventual removal of the closure from the bottle.

In the attached drawing:

FIGURE 1 is a section taken along lines A-B of the cap shown in FIGURE 2;

FIGURE 2 is a plan view of one embodiment of a cap embodying the present invention;

FIGURE 3 shows the cap illustrated in FIGURES 1 and 2 in place on a bottle, viewed from B and in partial section;

FIGURE 4 is a schematic drawing presented to illustrate the aforementioned retention effect;

FIGURE 5 is a section taken along lines C-D shown in FIGURE 6; and

FIGURE 6 is a plan view of another embodiment of the invention.

FIGURES 1 and 2 show the cap with its main surface or deck 1, skirt 2 and an annular sealing extension member 3 protruding downwardly from an intermediate portion of deck 1. Skirt 2 is provided with an inwardly projecting retention bead 4 which is adapted to reach under the external bead or lip 5 of the bottle as shown in FIGURE 3. Notches or grooves 6 are formed in the periphery of deck 1 and extend down into skirt 2 approximately to the level of retention bead 4 so that only relatively thin inner skin 7 remains. When such a skin is completely absent the notches become slots or perforations, but a tight seal with the bottle is nevertheless effected by means of inner seal member 3.

Referring to FIGURE 3, the arrow V is intended to indicate the direction of the internal pressure acting on the underside of the cap deck, causing the originally flat surface of the deck to become slightly arched. The retention bead 4 is pressed by the resulting pincer action more tightly into the recess or hollow 8 under bead 5 of the bottle as further shown in schematic FIGURE 4. The notches 6 divide the main deck 1 of the cap into

segments

9 and 10 which are connected hinge-like to each other by means of the bridge 11 remaining along the diameter extending between two opposite notches 6. The force acting on

segments

9 and 10 in the direction of the arrow presses the retention bead pincer-like by means of skirt 2 in the direction of the horizontal arrows H into recess 8 on the bottle neck. The increased inner pressure caused by liberated carbon dioxide thus increases the retention pressure of the retaining head in a cap formed in accordance with the present invention. In addition, the aforementioned hinge 11 has been found to facilitate the removal of the closure as Well as helping to overcome any substantial variations in bottle wall thickness.

The cap shown in FIGURES 5 and 6, instead of being provided with an integral sealing extension, contains a separate sealing insert 12 which is adapted to protrude into the bottle by means of its annular sealing member or hollow ring or plug 13. The central portion of the sealing insert embraced within the inner wall of the hollow ring abuts deck 1 of the cap from below and may be fastened to the latter by fusion. This facilitates subsequent opening of the bottle by hand. When the cap is lifted off the bottle by pressure of the thumb under the lift tab 15 the hollow sealing ring 13 at first remains wedged in the mouth of the bottle until the retention bead 4 begins to unlock and only continued lifting of tab 15 will cause the sealing ring or plug to be pulled from the bottle by means of the fused connection 16. When a tamper-proof cap is desired, lift tab 15 may be in the form of a downwardly open pocket having a sturdy front member serving as the actual lift tab and thin, frangible or tearable side walls or portions 17 through which the lift tab is connected to the skirt and which are torn when the tab is first lifted to open a fresh bottle.

While the cap shown in FIGURES 1 and 2 contains one pair of notches it will be observed that the cap shown in FIGURE 6 contains two pairs of notches or indentations 6.

It should be understood that several embodiments have been described to illustrate the invention, but that the latter is not intended to be limited thereby. For instance, it is possible to provide the separate sealing insert, in addition to the plug 13, with an outer skirt or cover which is adapted to totally or partially embrace bead on the bottle, in which event this skirt can carry its own inwardly projecting retention bead. In such a case the retention bead 4 of the cap should be adapted to extend this skirt of the sealing insert. It is likewise possible, instead of a continuous retention bead 4, to provide a plurality of small retention knobs or protuberances of appropriate thickness or rigidity permitting them to lock firmly under bead 5 of the bottle.

The invention for which protection is desired is particularly pointed out in the appended claims.

The claimed invention is:

1. A bottle cap of thermoplastic resin adapted for use with a bottle having an external bead near its mouth, which cap comprises a deck member, an outer skirt member, an internal sealing member adaptedv to abut the inside of said mouth, and a retention bead projecting radially inwardly from said skirt and adapted to become locked under said external bead of the bottle, said deck and skirt members having in their outer peripheral portending from saidvdeck member downwardly into said skirt member to about the level of said retention bead, said indentations terminating short of the skirt bottom.

2. A resilient thermoplastic cap adapted for use on a bottle'haviug an outwardly projecting bead near its mouth, which cap comprises a substantially flat circular deck member, a cylindrical skirt member attached to said deck member at the periphery thereof, a retention bead projecting from said skirt member radially inwardly, a sealing member adapted to extend into the mouth of a bottle, and a lift tab attached to the cap near the periphery thereof, said deck and skirt members having in their outer peripheral portions at least two groove portions located opposite each other along a diameter of said deck member and extending from said deck member downwardly into said skirt member to approximately the location of the retention bead thereon.

3. A cap according to claim 2 wherein said groove portions are arranged in a plurality of opposite pairs.

4. A grooved cap according to claim 2 wherein said lift tab is attached to said cap at a point which is located on a diameter perpendicular to a diameter on which two of said groove portions are located.

5. A grooved cap according to claim 2 wherein said lift tab is connected to said skirt member by a frangible connecting member which ruptures when the tab is lifted to raise the cap ofl? a bottle.

References Cited by the Examiner UNITED STATES PATENTS 2,156,258 5/1939 Atwood 215-46 X 2,987,206 6/1961 Grussen 21541 X 3,142,404 7/1964 Krieps 215-46 FOREIGN PATENTS 895,512 5/ 1962 Great Britain.

JOSEPH R. LECLAIR, Primary Examiner.

D. F. NORTON, Assistant Examiner.

Claims

2. A RESILIENT THERMOPLASTIC CAP ADAPTED FOR USE ON A BOTTLE HAVING AN OUTWARDLY PROJECTING BEAD NEAR ITS MOUTH, WHICH CAP COMPRISES A SUBSTANTIALLY FLAT CIRCULAR DECK MEMBER, A CYLINDRICAL SKIRT MEMBER ATTACHED TO SAID DECK MEMBER AT THE PERIPHERY THEREOF, A RETENTION BEAD PROJECTING FROM SAID SKIRT MEMBER RADIALLY INWARDLY, A SEALING MEMBER ADAPTED TO EXTEND INTO THE MOUTH OF A BOTTLE AND A LIFT TAB ATTACHED TO THE CAP NEAR THE PERIPHERY THEREOF, SAID DECK AND SKIRT MEMBERS HAVING IN THEIR OUTER PERIPHERL PORTIONS AT LEAST TWO GROOVE PORTIONS LOCATED OPPOSITE EACH OTHER ALONG A DIAMETER OF DECK MEMBER AND EXTENDING FROM SAID DECK MEMBER DOWNWARDLY INTO SAID SKIRT MEMBER TO APPROXIMATELY THE LOCTION OF THE RETENTION BEAD THEREON.