One-Piece Safety Closure for Rigid Containers Having a Bead Finish

The prior art contains many examples of closures designed to be difficult for children to open, but readily operable by adults capable of reading and following opening instructions. The great majority of such closures, however, have been designed for dispensing of liquids or granulated materials from narrow neck containers and, in many instances, involve the lifting of a locking flap from sealing engagement with one or more dispensing openings formed in the panel of the closure. In the case of wide mouthed containers, the products that are generally sold in such containers normally require the entire closure to be removed from the end of the container to permit proper dispensing of the contents of the container. A prime example is a paint container where the entire lid must obviously be removed from the wide mouthed container opening in order to permit the insertion of a paint brush. Many paints, varnishes and stains contain ingredients that would be harmful to small children if they gained access to them. Accordingly, there is a distinct need for a safety closure for a wide mouthed container which, when the closure is opened, results in the removal of the entire closure from the mouth of the container.

A safety closure constructed in accordance with this invention is specifically designed for use with a container having a wide mouth neck opening which is surrounded by what is known in the trade as a bead finish. Such bead is normally defined by an external rib on the neck above a radial shoulder, thus defining an annular groove in the outer surface of the neck, and the closure is formed of resilient plastic and provided with a generally vertically extending peripheral flange having an internally projecting rib which snaps into locking engagement with such groove. The safety package embodying this invention provides a vertically flexible bead finish of generally S-shaped configuration in cross section, with the lower loop of the S defining the annular closure retaining groove. The peripheral flange of the closure is then constructed so that the internally projecting rib snugly engages in the groove, but concurrently, the bottom rim portion of the closure flange is maintained in flush relationship with the adjacent side wall of the neck of the container. It is therefore impossible to insert a fingernail under the rim of the closure to effect the removal thereof.

To effect the closure removal, a segment of the internally projecting locking rib on the closure is provided with a vertically inclined bottom surface, instead of the normal horizontal surface. The application of a vertical force to the rim portion of the closure overlying such specially shaped segment will effect a downward depression of the relatively flexible bead finish at that location and the vertically inclined surface segment of the locking rib will be cammed outwardly by engagement with the adjacent edge of the closure retaining groove. This outward displacement of a segment of the closure rim permits a fingernail to be inserted under such segment and the closure to be thereafter stripped from sealing engagement with the container neck.

In a modification of this invention the vertically resilient neck portion of the container is defined by an internally projecting flange which is connected at its inner end with a radially outwardly and upwardly directed flange. The vertex end of such configuration provides an internal locking bead for the closure while the space between such flanges provides the external groove within which the bottom rim portion of the vertical flange of the closure is received.

In accordance with a modification of the invention, the principles of the invention may also be applied to a container having a relatively rigid finish portion. In such modification, sufficient space is provided between the top of the finish and the panel portion of the closure to permit a localized segment of the closure rim to be depressed downwardly through the application of a downward force and the vertically inclined surface provided on the bottom surface of such segment will be cammed outwardly by the adjacent edge of the closure retaining groove.

Further objects and advantages of this invention will be apparent to those skilled in the art from the following description taken in conjunction with the annexed sheets of drawings showing several embodiments of the invention.

FIG. 1 is a perspective view of a safety package embodying this invention, shown with the closure in assembled relationship to a wide mouth container having an external bead finish.

FIG. 2 is a partial sectional view taken on the plane 2--2 of FIG. 1.

FIG. 3 is a partial sectional view taken on the plane 3--3 of FIG. 2.

FIG. 4 is a view similar to FIG. 3 but showing the utilization of a fingernail inserted beneath the outwardly displaced segment of the closure rim to effect the stripping of the closure from the container.

FIG. 5 is a partial vertical sectional view showing a modified safety package embodying this invention wherein the neck portion of the container has an internal bead finish.

FIG. 6 is a view similar to FIG. 5 but showing the configuration of a selected portion of the container rim to which an opening force is applied.

FIG. 7 is a view similar to FIG. 6 but illustrating the outward camming of the rim segment of the closure through the application of a downward force to the top rim of the closure.

FIG. 8 is a partial vertical sectional view of a safety package embodying this invention wherein the container finish is relatively rigid.

FIG. 9 is a view similar to FIG. 8 but illustrating the outward camming of a segment of the rim of the closure through the application of a downward force to the top rim of the closure.

FIGS. 1 through 4 of the drawings disclose one embodiment of this invention as applied to a wide mouth container 1 formed of plastic material having some degree of resilience. The neck portion 2 of the container is formed with a corrugated or S-shaped configuration in vertical cross section and includes an inwardly extending flange portion 2a defining a generally horizontal top surface 2b, an outwardly and upwardly extending flange portion 2c, which is joined at its outer end with another inwardly and upwardly extending flange portion 2d. The vertex 2e of portions 2c and 2d defines an external closure retaining bead. The formation of the top end of the container neck in the described corrugated or S-shaped configuration obviously provides some degree of vertical flexibility to this portion of the container neck.

The closure 10 constructed in accordance with this invention is formed as an integral member molded from a resilient plastic material and comprises a generally circular panel portion 11 connected at its periphery to a flange portion 12 which is generally vertically disposed and is of inverted U-shape in cross section so as to snugly surround and engage the vertically flexible S-shaped neck portion. The inner wall 13 of the U-shaped vertical flange 12 abuts the end of neck flange 2d and the vertex 2f formed by the juncture of flanges 2a and 2c. The outer wall 14 of the vertical U-shaped flange 12 has an internally projecting rib 15 adjacent its lower rim portion which is contoured to fit in locking engagement beneath the vertex or bead 2e formed by the juncture of container neck flanges 2c and 2d. Additionally, the outer wall 14 is provided with a generally horizontal bottom surface 14a which snugly engages the upwardly facing surface 2b of the inwardly directed neck flange 2a. In this position, the surface of outer flange 14 is flush with the adjacent surface of the container neck 2. It is therefore impossible for a fingernail to be inserted underneath the lower rim of flange portion 14 to attempt to cam such rim to an unlocking position. For additional security, the radially outer portions of neck surface 2b may be slightly upwardly inclined. This presents inadvertent opening under top loading conditions.

In accordance with this invention, and as best illustrated in FIGS. 3 and 4, a limited accurate segment portion of the bottom surface 14a is provided with an upwardly inclined surface 14b. Because of the provision of such inclined segment surface, the application of a downward force to the flange 12 at a position overlying the inclined surface segment 14b will first effect a vertical compression or vertical folding of the neck flanges 2c and 2d. This will bring the inclined bottom surface segment 14b into engagement with the angular edge defined between the horizontal neck flange 2a and the vertical neck wall. As illustrated in FIGS. 1 and 4, this will result in a limited arcuate segment 14c of the bottom rim portion of the outer vertical flange wall 14 being displaced from its flush relationship with the side walls of the container neck 2, permitting a fingernail to be inserted under such outwardly displaced segment and sufficient force applied to the closure 10 to strip it from its sealing engagement with the container neck 2.

It will be recognized that the possibility of the closure being inadvertently removed from its closed position on the container is practically negligible. While the banging of the closure against a solid object may produce a momentary outward deflection of the wall segment 14c, if this is not concurrently followed by the insertion of the fingernail under the displaced wall segment, such wall segment promptly returns to its original flush position with respect to the container wall by its inherent resilience and the security of the closure remains undisturbed. Only the conscious application of a downward force to the particular rim area of the closure overlying the segment having the inclined bottom wall surface 14b, concurrent with the insertion of the fingernail under the slightly projecting rim portion 14c of that segment of the closure will effect the stripping of the closure from the container. Obviously, the required sequence of operations is beyond the capability of a child.

Referring now to the modification of this invention illustrated in FIGS. 5 through 7, the vertically flexible container neck 4 is shown as having only an inwardly directed horizontal flange 4a connected at its inner end with an outwardly and upwardly directed flange 4b, the vertices of the flanges 4a and 4b defining an internal locking bead 4c. The closure 15 includes a horizontal circular panel portion 16, to the perimeter of which is secured a generally inverted U-shaped flange 17 having a short vertical inner wall defining a groove 17a to snugly receive the internally projecting bead 4c, and an outer vertical wall 18 which has a generally horizontal bottom rim surface 18a engaging the top of the horizontal flange 4a so that the external surface of the outer flange 18 is essentially flush with the external neck wall 4d.

A relatively small peripheral segment of the outer flange wall 18 has its bottom surface formed as an upwardly inclined surface 18b as shown in FIG. 6. It follows then that the application of a vertical force to the top surface 18c of the outer flange 18 at a point located directly above the location of the inclined bottom surface segment 18b, produces an outward deflection of that segment 18d of the rim of the outer wall flange 18 by the camming action of surface 18b on the shoulder between flange 4a and side wall 4.

Again, it takes the application of a downward force to a very specific area of the rim of the closure 4 to effect an outward deflection of only a segmental portion of such rim sufficient to permit a fingernail to be engaged under the outwardly deflected portion 18d to effect the upward stripping of the closure from the container.

The principles of this invention may also be applied to metal, glass or plastic containers having relatively rigid neck portions. Referring now to the modification shown in FIGS. 8 and 9, the container neck 6 is shown as comprising a horizontal inturned flange portion 6a, connected to a vertical flange portion 6b which has an enlarged outer rim portion 6c on its top end, thereby defining a groove 6d for reception of a correspondingly shaped internal rib 22a formed on the bottom of a vertical flange portion 22 of a closure 20. Flange portion 22 is integrally connected to a panel portion 21 and is radially spaced from a depending flange portion 23 which snugly engages the inner vertical wall of the container vertical flange 6b.

The total height of the vertical flange portion 22 is selected to be in excess of the height of the vertical container flange 6b so that a space 6e is defined between the bottom wall 21a of the panel portion 21 and the top wall of the bead defining portion 6c of the container finish. Since the neck 6 has been assumed to be relatively rigid, it is readily apparent that no downward displacement of the closure 20 relative to the neck 6 can occur if all of the bottom surface 22b of the vertical flange 22 is horizontally shaped as shown in FIG. 8. However, as illustrated in FIG. 9, a limited angular segment 22d of the outer vertical flange 22 is provided with an upwardly inclined bottom surface 22c. When a downward force is applied to the rim of closure 20, immediately above the inclined surface segment 22c, the result will be an outward displacement of the rim segment 22d containing the inclined surface 22c, as illustrated in FIG. 9, permitting the fingernail of the person opening the container to be inserted under the projecting rim portion of the closure 20 to effect the stripping of the closure from the container 6.

From the foregoing description, those skilled in the art will recognize that modifications of this invention may be readily made without departing from the fundamental principles involved in the invention, and it is intended that the scope of the invention be determined solely by the appended claims.