US 3315832 A
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A ril 25, 1967 S OTT 3,315,832-
LINER FOR BOTTLE CAPS Filed Feb. 25, 1966 24 Z I v a, :0 :1 r I f :l' 4' f H I I F 30 34 1 \Jgzrll 26- -32 3b '-40 204K -38 2 2; I 1 I4\ I A8 FIG. 2 /''l6 1 g I l I I l f 1 3O 3 I N VEN TOR. DOUGLAS 0. SCOTT 3b 32 BY FALL. MW
38 40 f p I his AT 7' ORA/E Y5 United States Patent Connecticut Filed Feb. 25, 1966, Ser. No. 530,026
5 Claims. (Cl. 21556) This invention relates to improvements in containers and closures therefor, and more particularly, to containers having closures which seal the containers against leakage of the liquid content therein, but enable air to enter and gas to escape from the containers when pressure differentials exist between the inside and the outside of the containers.
Many types of liquid or semi-liquid products are currently sold in containers formed of polyethylene or polypropylene because of the attractive appearance and low cost, as well as the break-proof characteristics of these containers. Some dissatisfaction, however, arises from the use of these containers for the reason that upon changes in the temperature of the contents of the containers, they have a tendency to collapse somewhat and appear unfilled. Many liquids vaporize or expand causing the containers to bulge and become unsightly. Also, some of the compositions of the material sold in such flexible containers, as well as metal and glass containers, evolve gases and unless such gases are vented to the atmosphere to relieve the pressure, a substantial danger exists that such containers will explode.
The known disadvantages of such containers have led others to devise closures which are intended to prevent leakage of the liquid content of the container and at the same time allow gases, or increased pressures developed in the container, to escape to the atmosphere. Means for allowing the escape of the gases proposed heretofore include one way check valves of various designs, displaceable elements in a cap for uncovering venting apertures, and the like. Many of these prior devices are effective for use for such venting purposes but in the check valve closures proposed heretofore, no provision is made for allowing the entry of air into the container when a reduced pressure is developed in the container and thus, the prior devices are not effective to allow atmospheric air to enter the container to maintain substantial equilibrium conditions between the inside and the outside of the container.
In accordance with the present invention, a closure is provided for sealing a container against leakage of its contents, permit the escape of gas from and relieve the excess pressure in a container, and allow the entrance of air when the atmospheric pressure outside the container substantially exceeds the pressure within the container.
More particularly, in accordance with the present invention, the new liner is provided for closures or closure caps having a top wall and a side skirt for removable mounting on a container and a central slightly tapered plug extending downwardly from the top wall to engage in and seal the neck of the container. The new liner is a three-part structure comprising a thin, flexible, annular layer of liquid-impervious material, such as vinyl resin, polyethylene, polypropylene or the like, having a smooth upper surface adhered to the inside of the closure cap, and a fiber carrying lower surface. The plastic film or liner is thin and is normally supplied with a thin paper backing to support it and prevent it from being dam- 3,315,832 Patented Apr. 25, 1967 aged. In prior composite capliners, the paper backing is centered to a thin sheet of paperboard and the liner disks are cut from this assembly.
In accordance with the present invention, the synthetic plastic is stripped from its paper backing leaving fibers or fuzz-like particles on one surface of the film, while the other surface is smooth. A thin, annular member or ring, such as paperboard, corkboard, or the like, about two to four one-hundredths of an inch thick, is adhered to the fiber-carrying side of the plastic film by means of a suitable adhesive, such as paperboard glue. The opposite face of the paperboard ring is adhered to the fibercarrying side of an annular facing liner plastic film stripped from its paper backing, the smooth side of the facing liner being disposed outwardly to engage the rim of the container in liquid tight relation.
The openings in the annular facing liners are substantially smaller in diameter than the diameter of the opening in the paperboard such that the plastic extends inwardly beyond the inner edge of the paperboard ring. In addition, the unsupported ends of the plastic are cut at random spacings in order to facilitate installation of the composite liner. When the composite liner is placed around the central plug and against the top wall of the cap, the unsupported ends of the plastic are forced downwardly, and loosely join to abut the central plug in vertical fashion, the clearance between the plug and the paperboard approximating the combined thickness of plastic film adhered to the upper and lower surfaces of the paperboard. The overall diameter of the annular composite liner is large enough that it extends beyond the neck of the container with which it is associated.
Accordingly, when the cap is tightened onto the neck of the container, a liquid-tight relation is formed between the neck of the container and the cap member while air-gas leak paths exist in the composite liner. Air or gas will flow through the very small separation existing at the juncture of the unsupported ends of the plastic film liners and substantially all the air or gas will diffuse into or outside of the container through the porous annular paperboard. Some air or gas will diduse between the upper and lower surface of the paperboard and the fibercarrying sides of the plastic, the fibers creating air and gas leak paths through the adhesives.
For a better understanding of the present invention, reference may be had to the accompanying drawing, in which:
FIGURE 1 is a front elevational view of a typical container embodying the present invention;
FIGURE 2 is a view in cross-section taken on line 2-2 of FIGURE 1;
FIGURE 3 is a top view, partly insection of the composite liner;
FIGURE 4 is a view in cross-section taken on line 4-4 of FIGURE 3; and
FIGURE 5 is a perspective view of the liner removed from the bottle cap.
For the purposes of illustration, FIGURE 1 shows a cylindrical bottle 10 formed of glass, polyethylene, polypropylene, or the like. FIGURE 2 shows the bottle having a neck 12, with external threads 14, for receiving a closure cap 16, provided with internal threads 18. The threads '14 and 18 mesh loosely so that air or gas can flow readily between the neck 12 and the skirt 20 of the cap 16 which engages the neck 12. Cap 16 is further provided with a downwardly tapering protrusion or or plug 22 which extends from top wall 24 and is adapted to engage relatively tightly in the internally tapered neck 12 of container 10. In accordance with the present invention, the cap 16 is provided with a sealing liner 26 of three-part structure, which, as mentioned above, seals the container against leakage of the liquid content therein, but also allows the inward and outward leakage of air and gas to equalize substantially the inner pressure of the bottle with the outer atmospheric pressure. As illustrated in FIGURES 2, 3 and 4, liner 26 comprises a thin, flexible, annular layer or ring 28 of liquid impervious plastic material, such as vinyl plastic, having a smooth upper surface, a portion of which is to be disposed adjacent to the inside of the top wall 24- of cap 16 and a fiber-carrying lower surface. As mentioned above, when a sheet of plastic film is stripped from its paper backing, it carries with it fibers or fuzz-like particles from the backing which form a felt or fuzz on the surface of the plastic which had been coextensive with the backing.
The upper face 30 of thin, annular member or ring 32, is adhered to a portion of the fiber-carrying side of the plastic film 28 by means of a suitable adhesive 34, such as paperboard glue. Member 32 is formed of a suitable backing material such as paperboard, cork, or the like.
The opposite face 36 of the ring 32 is adhered to a portion of the fiber-carrying side of a ring like facing liner 38 by means on an adhesive Facing liner 3% is formed of liquid-impervious material, such as a vinyl plastic and, like the plastic ring 28 adhered to the upper surface 3th of the paperboard 32, it too has been stripped from its paper carrier. The smooth side of the liner 3? is disposed outwardly to engage the neck 12 of the container in liquid-tight relation.
As best illustrated in FIGURES 3 and 4, the central openings in the liners 2d and 3% are smaller than the opening in the ring -32 so that the plastic liners 2d and 38, extend partially across the central opening in the ring 32. The diameter of the opening in the paperboard 32, while substantially larger than the opening in the plastic, is selected such that the radial clearance between the ring 32 and the tapered central plug 22 is slightly greater than the combined thickness of plastic film liners 23 and 32, e.g., the distance between the plug 22 and the inner edge of the ring 32 approximates four to eight one-thousandths of an inch. Furthermore, in the preferred embodiment of the invention, as best shown in FIGURE 3, the downwardly extending edges of the rings 28 and 33 are cut so that each has a plurality of slits 42 in offset relation. The existence of the slits 42 facilitates the installation of the composite liner 26 since the unsupported inner edges of the rings 28 and 33 are forced downwardly when the liner 26 is pressed over the plug 22 and against the top wall 24 of the closure cap 20 as shown in FIGURES 2 and 5.
As shown in FIGURE 2, the inner edges of the rings 28 and 38 are gripped between the tapering surfaces of the plug 22 and the neck 12 of the bottle at a point below the horizontal plane of the ring 32. As mentioned above, the diameter of the opening in the ring 32 is selected such that the radial clearance between the plug 22 and the paperboard 32 is slightly greater than the combined thickness of the plastic film rings and, because of this, the plastic forms a relatively tight wedge between the ring 32, the plug 22 and the bottle neck 12 which unseats them and the remainder of the cap slightly. In this way the portion of the liner 26 between the wall 24 of the cap and the neck 12 of the bottle cannot be compressed sufficiently to render the liner 26 gas-tight. The overall diameter of the composite liner 26 is sufficiently wide that it extends beyond the neck 12 of the bottle lib.
Thus, it can readily be seen that the composite liner 26 forms a liquid leak-proof wedge between the neck 12, the plug 22 and the inner top surface of the closure cap 16 when the cap 16 is tightened onto the neck 12. Nevertheless, a finite separation exists between the inner edges of the liner rings 28 and 38 and the tapered surfaces of the plug 22 and the bottle neck which will allow air or gas to flow through the opening but is small enough to minimize the leakage of the liquid content contained in the container it). Air or gas can diffuse between the liner rings 23 and 38 into or outside the container through the air and gas porous paperboard and can also fiow through Elise felted or fuzz-covered sides of the liner rings 28 and Accordingly, when the pressure inside the container 10 is greater than the pressure outside the container 10, gas can diffuse through the spaces between the plug 22, the downwardly extending edges of the liner rings 23 and the neck 12 through paperboard 32 and through the fibers or fuzz on the rings 28 and 38 and through the gap between neck 12 and skirt 24) of cap 16.
Similarly, if the pressure outside the container 10 is greater than the pressure inside the container 10, air will enter through the gap existing between neck 12 and side skirt 20, annular ring 32, fuzz layers 34 and 40 and the opening between the neck 12 and plug 22 provided by the intervening edges of the liner rings 28 and 38.
It will be understood that the invention is susceptible to considerable modification, for example, the inner unsupported edges of the liner rings 28 and 33 need not be cut at various spacings in order to achieve the desired result. The diameter of the openings in the plastic films 28 and 35; can be unequal, or equal so long as they can be deflected beyond the plane of the lower surface of the ring 32. Similarly, modifications can be made in the shape of the container iii, in the material which the container 10 and closure cap 16 are made, and the shape of vertical plug 22. Accordingly, it will be understood that the embodiment of the invention disclosed herein as illustrative and the invention limited only by the terms of the following claims.
1. A breath-able closure for a container having a pouring opening defined by a circumferential rim, comprising a cap member having a top wall and a side skirt for removable mounting on said container, a protrusion tapering downwardly from said top wall for engagement in the neck of said container, and a liner adhered to the inside of said cap for engaging the neck of said container in liquid-tight relation, said liner comprising a first annular layer of liquid-impervious material adhered to the inside of said top wall, a second annular layer of porous material having an upper surface adhered to said first layer of material and a lower surface adhered to an annular facing liner formed of liquid-impervious material and engaging the rim of said container, said first layer of material and said facing liner comprising openings smaller in diameter than the opening in said second layer of material and the radial clearance between said protrusion and said second layer of material being slightly greater than the combined thickness of said first layer of material and said facing liner such that the inner edges of said first layer and said facing liner extend vertically into the neck of said container to form a liquid-tight air-porous wedge between said protrusion, said rim of said container and the inner surface of said cap member.
2. A breathable closure according to claim 1, wherein said first layer of material and said facing liner are formed of plastic and stripped from their respective backings before adherence to said second layer of material, said first layer of material and said facing liner each carrying fibers on one side, and said second layer of material is formed of paperboard.
3. A breathable closure according to claim 2, wherein the fiber-carrying side of said first layer of material and said facing liner are adhered to the upper and lower surfaces of said second layer of material, respectively, the fibers increasing the air and gas porosity of said liner, and
5 6 wherein said inner edges of said first 'layer of material and References Cited by the Examiner said facing liner possess a plurality of slits for facilitating UNITED STATES PATENTS the installation of said line-r.
4. A breathable closure according to claim 1 wherein 18811 the diameter of the opening in said facing liner is larger 5 FOREIGN PATENTS than the diameter of the opening in said first layer of m-a- 517,904 3/1955 Italy.
5. A breathable closure according to claim -1 wherein JOSEPH R. LECLAIR, Primary Examiner. said container is a flexible bottle. D. F. NORTON Assistant Examiner.
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