US2765960A

US2765960A - Reusable retentive closure for containers

Info

Publication number: US2765960A
Authority: US
Inventors: Jack W Soffer; Doanld M Kitterman
Original assignee: Development Research Inc
Current assignee: Development Research Inc
Priority date: 1953-07-27
Filing date: 1953-07-27
Publication date: 1956-10-09
Anticipated expiration: 1973-10-09

Description

Oct. 9, 1956 J. w. SOFFER ET AL 2,755,960

REUSABLE RETENTIVE CLOSURE FOR CONTAINERS Filed July 27, 1953 INVENTOR JACK W. SQFFEER 8 DONALD M. MWTERMAN j Z W,

ATTORNEY REUSABLE RETENTIVE CLOSURE FOR CONTAINERS Jack W. Solfer, St. Louis, and Donald M. Kitterman, Kansas City, Mo., assiguors to Development Research, Inc., St. Louis, Mo., a corporation of Missouri Application July 27, 1953, Serial No. 370,489 Claims. (Cl. 222--182) This invention relates to reusable retentive closures for containers and specifically to molded plastic protective closures employed on steel dispensing containers to avoid inadvertent tilting of the dispensing valves and accidental discharge of the container contents.

An objective of the present invention is to provide such protective closure which is relatively difiicult to remove from the container the first time such removal is attempted, but which may be readily removed on reuse. The original retention of the closure to the container must offer such resistance to removal that the user may be confident that the container has not theretofore been opened.

After the container has once been opened, it is preferable that the closure be readily removable, and pos sess only enough retention to avoid being dropped off or dislowdeg by chance physical contact.

A further object of the invention is to provide a reusable retentive closure which may be originally removed from the container to which it is aflixed either by twisting or prying.

A further purpose is to provide retentive lugs integrally molded into the skirt of a plastic closure, which lugs are automatically shaved off on removal of the closure, the extent of shaving being sufficient to permit removal thereafter without substantial expenditure of effort.

A further purpose is to provide a steel-topped container with a downward-presented edge adapted to shave the closure lugs to reduce their retentive ability the first time the closure is removed from the container edge.

The foregoing and additional objects will be made clear from the following specification and the accompanying drawings (one sheet) in which:

Figure 1 is an elevational view of a steel container bearing a closure embodying the present invention.

Figure 2 is an enlarged sectional view taken along line 22 of Figure 1.

Figure 3 is an enlarged sectional view 3-3 of Figure 2.

Figure 4 is a fragmentary sectional view showing a portion of Figure 2 to larger scale.

In the embodiment illustrated, a low-pressure steel container 1 (the lower portion of which is not shown in the drawings) is fitted with an annular top 2 by swaging the top 2 radially outward within the neck of the container 1. The top 2 is formed by blanking sheet metal, ordinarily steel, and forming around its edge an annular rim 3 terminating in a downwardly and outwardly rounded camming surface 4, and a downwardly-presented peripheral ledge 5. These parts are shown in their respective positions in Figure 2 of the drawings, and are shown enlarged in Figure 4.

In the blanking of sheet metal, the outer edge of the object formed by blanking presents two different portions, a smooth portion formed by cutting or shearing, normally extending about half of the thickness of the sheet metal, and a rough sharp edge portion extending the taken along line States Patent 0 balance of the thickness of the metal and brought about by the breaking of the part of the partially sheared sheet. Accordingly, the edge 5 possesses two distinct portions, a shear portion 6 which is located nearest the central axis designated a, of the container enclosure, and a break portion 7 which continues outward from the shear portion 6 for the remainder of the thickness of the metal utilized in the top 2. The juncture of the break portion 7 with the camming surface 4, when examined under optical magnification, shows a relatively rough and sharp edge even after tumbling; although not more so than results from acceptable standards of shop practice. We take advantage of this roughness in that it causes the edge to grasp retentively into molded plastic materials and on movement to cut or shave them.

At the center of the annular top 2 there is provided along the axis a a tiltable discharge valve, generally designated 8, equipped with a sealing grommet 9 in which the discharge valve is rockably mounted.

When valves such as the discharge valve 8 are used on containers filled with fluid and gas, it is necessary that they be protected from inadvertent discharge by tilting. Many types of plastic closures have been suggested for this purpose. In the present invention there is employed a reusable retentive closure, generally designated 10, formed of plastic by injection molding, and having an open'ended annular skirt 11 whose inner diameter is greater than the outer diameter of the annular rim 3 of the container top 2. The closure 10 is adapted to be applied axially downward over the annular rim 3, and to be held thereon by a plurality of circumferentially spaced retention lugs 12 molded integrally with the closure skirt. The lugs 12 have inwardly-presented grasping surfaces 13 which converge from the upper portion of the skirt 11 to .its lower margin 14. The amount of convergence is such that at their lower, innermost points the radial spacing of such grasping surfaces 13 from the axis a, is less than the radial distance to the outermost portion of the annular rim 3. The portion of the retention lugs 12 which extends inward of the outer margin of the annular rim 3 is shown in Figure 4 to the left of the line bb, and is designated the shave-off portion 15 of the lugs 12. The bottom margins 16 of the lugs 12 serve a cam function hereinafter described.

After the container 1 has been filled, the annular top 2 swaged sealingly thereon, and gas inserted through the discharge valve 8, the closure 10 is placed with the bottom margins 16 of the lugs 12 on the outwardly rounded camming surface 4 of the top 2. Axial force applied to the top of the closure 10 presses the bottom margins 16 against the camming surface 4, deflecting the skirt 11 in the region of the lugs 12 to permit its lower margin 14 to pass over the annular rim 3. The grasping surfaces 13 of the lugs 12 will pass readily over the rounded camming surface 4 without damage to the lugs 12.

With the closure 10 in position on the container 1, as shown in Figure 2, there is contact between a sharp steel edge 5 of the annular rim 3 and the retention lugs 12 of the plastic material of the closure. The retention of the plastic material to such sharp edged annular lip is positive; it is readily apparent on manipulating the closure 10. A purchaser familiar with its firm resistance to movement is assured by the feel of such positive retention that the closure 10 has not theretofore been removed.

The user may remove the closure 10 either by axial prying under the lower margin 14 of the skirt 11, or by twisting and exerting an axially outward pull on the closure 10. Whether the force applied is by prying, twisting or pulling, the effect will be to bring the sharp rough edge 5 in scraping contact against the grasping surfaces 13, shaving off the shave-off portion 15 of the retention lugs 12. The closure may thereafter be replaced and removed readily, serving as a convenient reusable protective cover for the discharge valve 8, and also serving to disclose the fact that the closure 10 has been removed from the container 1 at least once previously. Thus, any unauthorized removal of the closure 10 may be readily detected.

Other embodiments of the invention principles herein disclosed will be apparent to those skilled in the art. Accordingly, the present invention is to be considered as coextensive with the inventive principles herein disclosed.

We claim:

1. For use with a steel container having an annular top mounting a discharge valve, such top having a rough downwardly-presented peripheral edge at its outer margin, a molded plastic protective closure adapted to be applied axially downward over such peripheral edge, the said closure having an open-ended annular skirt, the inner radius of said skirt being greater than the radius of the annular top of such container, further having circumferentially spaced retention lugs molded integral with the inner wall of said skirt, the said retention lugs having inwardly-presented grasping surfaces converging downwardly from the inner wall of the skirt to a radial spacing adjacent the lower margin of the skirt less than the radius of such annular container top, the said grasping surfaces being adapted to grasp the outer margin of such annular top along and beneath the rough downwardly-presented edge thereof, and to be shaved to an increased radial spacing by scraping movement over the rough edge of the container top incident to removal of the closure from the container.

2. In combination with a steel container having an annular top mounting a discharge valve, said top having a rough downwardly-presented peripheral edge at its outer margin, a molded plastic protective closure adapted to be applied axially downward over said peripheral edge, the said closure having an open-ended annular skirt, the inner radius of said skirt being greater than the radius of the annular top of said container, further having circumferentially spaced retention lugs molded integral with the inner wall of said skirt, the said retention lugs having inwardly-presented grasping surfaces converging downwardly from the inner wall of the skirt to a radial spacing adjacent the lower margin of the skirt less than the radius of said annular container top, the said grasping surfaces being adapted to grasp the outer margin of said annular top along and beneath the rough downwardly-presented edge thereof, and to be shaved to an increased radial spacing by scraping movement over the rough edge of the container top incident to removal of the closure from the container.

3. The combination defined in claim 2, the annular top of the container having a downwardly and outwardly rounded camming surface adjacent its rough downwardlypresented edge, whereby on applying said closure axially downward, the lower margins of the retention lugs engage said camming surface and are spread thereby radially outward suficient to permit the passage of the lower margin of said annular skirt over the annular top of the container.

4. The combination defined in claim 2, the annular top being formed by blanking, the shear portion of its peripheral edge being on the inner side of the annulus and the break portion of said edge being on the outer side of the annulus, whereby said break portion of the peripheral edge is presented for contact with the grasping surfaces of the retention lugs.

5. A reusable retentive closure characterized by lesser retention on reuse, comprising a molded plastic closure adapted to be applied axially downward over a sharp edged annular lip, the said closure having an openended annular skirt, and spaced retention lugs molded integrally With the inner Wall of said skirt, the said retention lugs having inwardly-presented grasping surfaces converging downwardly from the inner wall of the skirt to a radial spacing adjacent the lower margin of the skirt, which spacing is less than the radius of said lip, the said grasping surfaces being adapted to grasp the outer margin of said lip along and beneath the sharp edge thereof, and to be shaved to an increased radial spacing by scraping movement over said sharp edge and incident to the first removal of the closure from said lip.

References Cited in the file of this patent UNITED STATES PATENTS