This invention relates in general to new and useful improvements in closures, and more particularly to a closure which is preferably formed of a plastic material and which has a snap-in interlock with a container neck finish and wherein the closure has a sealing plug portion which is initially integrally formed with an outer annular retaining ring portion, but wherein the connection between the two portions includes a line of rupture with the exception of a hinge wherein opening of an associated container is effected by pressing in the sealing plug portion.
The closure is particularly adapted for use in conjunction with a container having a liquid packaged therein under internal pressure, with the sealing plug portion being provided with a vent passage which is normally closed by a plug valve which may be axially inwardly depressed to open the vent and relieve internal pressure within the container before the sealing plug portion is pressed inwardly to its open position.
Another feature of the invention is the relative diameters of the sealing plug portion and a locking shoulder which is innermost of the neck finish and defines a pour opening normally closed by the sealing plug portion wherein, when the sealing plug portion is pressed inwardly to a generally out-of-the-way position, it will be frictionally retained in such open position.
Yet another feature of the invention is the formation of a hinge as a strap having elongation properties which permits the axial inward movement of the sealing plug portion. The elongation properties may be enhanced by the provision of transverse weakening lines in the strap or by other mechanically induced elongation means.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims, and the several views illustrated in the accompanying drawings.
In the Drawings
FIG. 1 is a fragmentary top plan view of a container closed by a closure in accordance with this invention.
FIG. 2 is an enlarged top plan view showing further the details of the closure of FIG. 1.
FIG. 3 is a fragmentary vertical sectional view taken generally along the line 3--3 of FIG. 2, and shows a specific cross section of the closure and the mounting thereof on a neck of an associated container.
FIG. 4 is another fragmentary sectional view similar to FIG. 3, but showing the vent valve in an open or venting position.
FIG. 5 is a further fragmentary vertical sectional view similar to FIG. 3, and shows the sealing plug portion of the closure pressed inwardly to an open or dispensing position.
FIG. 6 is a top plan view of the opened container of FIG. 5.
Referring now to the drawings in detail, it will be seen that there is illustrated a container 10 which is provided with a neck finish, generally identified by the numeral 12, having permanently associated therewith a closure generally identified by the numeral 14.
The container 10 has an upper wall portion 16 from which the neck finish 12 extends. The neck finish 12 includes a generally conical portion 18 which terminates in a radially inwardly and axially inwardly extending flange 20 which generally defines a locking shoulder, the function of which will be described hereinafter. The flange 20 has joined thereto an upwardly and radially outwardly sloping frustoconical mouth portion 22 by means of an intermediate reversely turned part 24. The mouth defining portion 22 terminates in a radially outwardly and downwardly turned curl 26.
In the preferred embodiment, the closure 14 is formed of a suitable injection moldable plastic and includes an outer retaining ring 28 which is formed on the underside thereof with an annular socket 30 having a snap interlock with the curl 26 permanently to retain the closure 14 on the neck finish 12.
The closure 14 also has an inner sealing plug portion generally identified by the numeral 32. The sealing plug portion 32 has a slightly concave end panel 34 and a depending skirt portion 36 which flares slightly downwardly and includes a lower enlargement 38 which defines a locking flange 40. The locking flange 40 is positioned to engage behind the shoulder 20 as well as behind the reversely turned part 24 both to lock the sealing plug portion 32 within the neck finish and to form a seal therewith.
The sealing plug portion 32 is releasably integrally connected to the retaining ring portion 28 along a generally circular weakening line 38 with the exception of a hinge 40 which is in the form of a strap.
The end panel 34 is provided with a vent passage 42 in alignment with the hinge strap 40 and remote therefrom. The vent passage 42 is in part defined by an opening 44 in the end panel and in part by a depending housing 46 having a lower retaining flange 48.
The vent passage 42 is normally closed by means of a vent valve 50 which includes a plug portion 52 having an enlarged intermediate portion 54 of a size tightly to fit within the opening 44. The vent valve 50 further includes a piston-like innermost part 56 which is of a diameter to seat on the underside of the end panel 34 surrounding the vent opening 44 to form a seal therewith.
The vent valve 50 is preferably hollow, having a recess 58 formed therein. Then the underside of the vent valve 50 is subjected to pressure from within the associated container 10, not only does the vent valve assume the position illustrated in FIG. 3, but also it expands radially to form a tight seal with the end panel 34.
The hinge strap 40, depending upon the specific plastic material utilized in the formation of the closure 14, may have considerable elongation properties. On the other hand, it may be desirable to provide mechanical means to facilitate the elongation of the hinge strap 40. With particular reference to FIG. 2, it will be seen that the hinge strap 40 may be provided with series of relief lines 60 extending transversely of the hinge strap 40, but not extending entirely through the thickness of the hinge strap. These relief lines 60, when the hinge strap 40 is tensioned, serve to permit an opening up of the hinge strap and an elongation thereof such as occurs when a sheet of metal is slit and then tensioned in a direction transversely of the slits in the formation of expanded metal.
In the operation of the closure 14, opening is effected by pushing down on the vent valve 50, moving it radially inwardly into the interior of the container to the extent permitted by the housing 46, as shown in FIG. 4. This results in the venting of pressures from within the container 10. Continued pressure on the vent valve 50 will apply pressure to the end panel 34 and effect rupture thereof along the weakining area 38. Once this rupture occurs, the sealing plug portion 32 may be snapped out of engagement with the locking shoulder 20 and the reversely turned portion 24 with the part of the depending skirt portion 36 underlying the hinge strap 40 pivoting on the revesely turned portion 24 and the sealing plug portion 32 pivoting to an open position within the container as shown in FIGS. 5 and 6. It will be seen that the sealing plug portion 32 remains attached to the retaining ring 28 by way of the hinge strap 40 with the hinge strap 40 being placed in tension by the pivoting action and becoming elongated.
It is to be particularly noted that the diameterof the end of panel 34, particularly that part which extends radially outwardly of the skirt 36, is of a greater diameter than the diameter of the pour opening defined by the revesely turned portion 24, and thus there is a wedging of the sealing plug portion 32 within the pour opening so as to retain the sealing plug portion 32 in the position to which it is depressed.
Once the sealing plug portion 32 has been ruptured relative to the remainder of the closure 14 and pressed inwardly into the container 10 to the position shown in FIGS. 5 and 6, the product packaged within the container 10 may then be readily poured therefrom.
Although the closure 14 is primarily intended to be utilized in conjunction with products which are packaged under pressurized conditions, it is to be understood that the closure could be utilized in conjunction with the packaging of liquids at atmospheric pressures. In such event, consideration may be given to the elimination of the vent opening 42 and the vent valve 50.
Although only a preferred embodiment of the closure has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the closure without departing from the spirit and scope of the invention as defined by the appended claims.