US2465842A

US2465842A - End closure for paperboard containers

Info

Publication number: US2465842A
Application number: US582385A
Authority: US
Inventors: Lewis C Brooks
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-03-12
Filing date: 1945-03-12
Publication date: 1949-03-29
Anticipated expiration: 1966-03-29

Description

March 29, 1949. c. BROOKS END CLOSURE FOR YAPERBOARD CONTAINERS 2 SheGts-Sheet 1 Filed Marh 12, 1945 L'wz's U Emzaks March 29, 1949. I.. c. BROOKS 5,

END CLOSURE FOR PAPERBOARD CONTAINERS Fil ed March 12, 1945 2 Sheets-Sheet 2 QM (VF Mar. 29, 1949 Patented i i I END CLOSURE FOR PAPERBOARD CONTAINERS Lewis 0. Brooks, Milwaukee, Wis., assignor of one-third to Ira Milton Jones, Milwaukee, Wis.

Application March 12, 1945, Serial No. ssasss This inventionrelates to closures for containers and is a continuation in part or the co-pending application of Lewis 0. Brooks, Serial No. 518,991, filed January 20, 1944, now Patent No. 2,398,405, issued April 16, 1946.

In the aforesaid application the container illustrated is made oi paper board and the shoulder construction at the mouth or the container and which supports the closure is produced through a novel manner of folding the blank from which the body of the container is made. A flat disc secured on this shoulder and having an aperture larger than the mouth of the container at said shoulder so as to leave aledge at the inner marginal portions oi the shoulder cooperates with the ledge to securely hold the closure in place sealing the open top 01 the container. The closure includes a sealing sheet disposed over the disc and wedged into the aperture of the disc and onto the ledge by a relatively stifl insert bonded to the sealing sheet and ota size to snugly fit the disc aperture.

While this construction is admirably suited for containers made 01 paper board and the like, it is possible to embody the invention in a construction wherein the stepped-down inwardly projecting ledge is formed integrally with the body of the container at the mouth-thereof. For

instance, the container body might be molded of glass, pulp, or plastic. and it-is one of the obiects oi. this invention to provide a simple but eillcient and positive unitary sealing closure for such molded containers.

More specifically it is an object of this invention to provide an inexpensive sealing closure for the open tops oi molded or glass containers having fiat upright side walls and convenient for packaging milk, dairy foods, and other 'products, and which in addition to sealing the mouth oi the container acts to protect the rim of the container at the mouth against contamination.

with the above and. other objects in view which -willappear as the description proceeds, this invention resides. in the novel construction, combination and arrangement of parts substantially as hereinaiter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope oi the claims.

The accompanying drawings illustrate several complete examples of the physical embodiment oi the invention constructed according to the best modes so far devised for the practical application oi the principles thereof, and in which:

2 Claims. (01. era-5.5)

. 2 a Figure 1 is a fragmentary perspective-view oi the top portion of a molded container particularly adapted for packaging milk, dairy or other products, and showing the sealing closure 01 this invention applied thereto;

Figure 2 is a fragmentary cross sectional view through a side wall portion or the container at the mouth thereof;

Figure 3 is a perspective-view oi the sealing closure viewing the same from the top side thereof and before its application to the mouth of the container; 7

Figure 4 is a view similar to Figure 1 but illustrating a slightly modified form of closure tor the container mouth; 1-

Figure 5 is a view similar to Figure 3 illustrating the top side of the closure shown in Figure 4, before its application to the container mouth;

Figure 6 is a view similar to Figures 3 and 5 illustrating a still further modified type of seal-' ing closure; and

Figure '7 is a fragmentary perspective view of space and permits considerable reduction in the sizes or crates and cartons employed in shipping such containers. However, where square that sided containers have been used the conventional round restricted neck designed to take the conventional bottle caps andcovers was retained. As a result, these fiat sided containers were undesirable because of the inconvenience and dimculty attending the removal of semi-solid food products through the restricted necks or such containers. This objection has inthe past dissuaded the packaging 01 other than liquid food products in the fiat sided containers.

The container of this invention, however, distinguishesirom past containers in that it is provided with flat side walls defining a uniformly square or rectangular cross section throughout the entire depth of thecontainer and terminating in a more or less-fiat rim II at the upper full open end or mouth of the container.

A stepped-down ledge i2 formed integrally with and projecting inwardly from the side walls of the container around the entire inner periphcry of the mouth thereof adjacent to the rim II provides a supporting surface I3 spaced a slight distance beneath the top of the rim Ii for the sealing closure M of this invention.

The sealing closure 14 comprises a relatively thin flexible sealing sheet [5 placed across the open mouth of the container so as to cover the rim H thereof and wedged into place covering the container mouth by a stifi insert or disc Hi to which it is bonded and of a size and shape to snugly fit the sides of the rim above the ledge l2 without projecting above the top of the rim I I. Although the insert ideas not project above the top surface of the rim II it nevertheless serves to tightly press the sealing sheet l5 down onto the supporting surface 13 of theledge and against the sides of the rim to form a secure Joint at the mouth of the container.

As clearly illustrated in Figure 3, it will be seen that the sealing sheet i5 is bonded to the insert l8 prior to application of the closure to the mouth of the container and this is preferably eflected by means of a permanent adhesive.

The underside of the flexible sealingsheet is adhered to the supporting surface 13 of the ledge, the top of the rim I I to protect the same against contamination, and the inner sides of the rim adjacent to the ledge by means of a repeatedly eflective pressure sensitive adhesive. Such an adhesive enables the marginal portions of the sealing sheet to be repeatedly lifted to uncover the container mouth and reapplied to seal the container mouth a number of times at will,

The adhesive employed for this purpose may consist in a synthetic wax with strong adhesive qualities, for example, or may be of the type commonly used on Scotch tape whose effectiveness for repeated use as a sealing medium is well known.

The act of uncovering the container mouth is facilitated by means of an extension of one side edge of the sealing sheet l5 forming a pull tab l'l normally adhered to one of the outer side walls of the container by the same repeatedly effective pressure sensitive adhesive in the closed position of the cover. The portion of the strip l5 opposite the pull tab may, obviously, serve as a hinge by its adhesion to the rim Ii during uncovering of the-mouth of the container.

If desired, the sealing sheet l5 may be provided with flanges l8 integral therewith as shown in Figures 4 and 5 to extend around the top of the rim II and to overlie the sides of the, container to afford better protection against contamination of the exterior surfaces of the container over which its contents is likely to be dispensed and to afford better protection against accidental displacement of the closure. These flanges are likewise adhered to the outer side walls of the container by a repeatedly effective pressure sensitive adhesive of the type previously described, and any one of the flanges may serve as a pull tab in opening the container.

In place of the repeatedly eifective adhesive sensitive to pressure alone, it may be advantageous in some instances (depending upon the type of goods packaged) .to employ a special adhesive sensitive to or activated by both heat and pressure for attachment of the sealing closure of this invention to the mouth of the container. Certain synthetic waxes applied to the closure, one of which is known to the trade as Flexo C-Light," have such characteristics as to enable the closure to be sealed in place with a tenacity depending upon the degree of heat employed, in combination with pressure, during application of the closure to the container mouth.

When the proper degree of heat is employed in the initial sealing operation, such an adhesive acts to securely hermetically seal the container mouth and to afford ample protection against accidental displacement of the closure during handling of the filled container, but permits the closure to be lifted in the hereinbefore described manner to uncover the container mouth for dispensing of the container contents. Also, this particular type of adhesive permits resealing of the closure after partial dispensing of the container contents merely by the application of pressure alone; the adhesive thus becoming repeatedly pressure sensitive after initial opening of the closure to allow rescaling of the container a number of times at will. a

For molded containers of the type shown and which are repeatedly refilled by the producer, the degree of heat employed with-pressure in initially sealing the closure would obviously be less than for paper board containers or others of the molded type used once and then discarded.

Some molded containers, especially those for milk, require thorough washing and cleansing and a permanent bond between the sealing closure and container mouth must be avoided. If preferred, however, one marginal edge or flange of the closure which is to act as a hinge may be sealed to the rim or outer side wall of the molded container with a greater tenacity than the remaining portions of the closure by the application of slightly more heat to said edge or flange so as to prevent accidental removal of the entire closure during opening of the container.

As will be apparent, this same type of adhesive is equally desirable for sealing the end closure of this invention to paper board containers having similarly designed mouth and of the type shown and described in the aforementioned copending application of Lewis C. Brooks, Serial No. 518,991, flied January 20, 1944. When so employed, it is possible to bond the portion of the sealing sheet which is to act as a hinge permanently to the container by the application of a suitable high degree of heat (and pressure) thereto during initial sealing. Permanent sealing of the hinged edge is, of course, also possible with such molded or glass containers as are 'used once and then discarded.

Inasmuch as the sealing sheet is preferably adhered tightly to the container mouth with this synthetic wax adhesive so as to enable hermetic sealing of the container contents, the sealing sheet must in all cases be stronger than the sealed joint to enable the joint to be broken without improper tearing of the sheet.

When a flanged closure is employed, it may also be desirable to provide the flexible sealing strip IS with perforations I9 along opposite side edges thereof at the bend line of the flanges as shown in Figures 6 and 7 and along which the cover may be conveniently torn open. One side 20 of the sealing strip is preferably left imperforate so that it may act as a hinge for the closure disposed either on the top surface of the rim or upon-the outer rear side wall adjacent thereto upon tearing of the. strip along its perforations is to uncover the container mouth as illustrated in Figure 7.

When such perforations are used, the flange opposite the side 20 may be imperforate to act as a pull tab or a special pull tab 2| may be provided thereon. This tab 2| as shown in Figure '7, is formed by a central imperforate section of the flange l8 opposite the hinge 20 having perforations 22 along its side edges leading from perforations l9 similar to the perforations l9 to the free edge of the flange.

The tab 2| facilitates opening of the cover inasmuch as it merely requires loosening of a small portion of the flange from the side wall to which it is adhered to enable tearing of the strip along its perforations in the manner hereinbefore described. Obviously, the outer edge portion of the tab 2! may be left free of the container side wall to facilitate grasping the same.

I the mouth of a multiple sided container having rigid side walls comprising: a ledge integral with the side walls of the container an'dspaeddown from the end thereof, said ledge extending entirely around the inner periphery of the mouth of the container; an insert of a size to flt snugly into the mouth of the container so as to rest on said ledge; a thin, flexible sealing sheet adhered to the underside of said insert and projecting beyond the edges of the insert; a'repeatedly effective pressure sensitive adhesive on the underside of said sheet by which the marginal portions thereof are removably adhered to the ledge and the wall surfaces defining and adjacent to the tainer; and repeatedly effective pressure sensitive adhesive on the undersides of said flanges by which they are adheredto the side walls, said thin sealing sheet being weakened at the junctures of the side flanges to the sheet proper along all but one of the sides, but with its line of weakness at the juncture of th flange opposite said one side interrupted for a distance and with the line of weakening turned outwardly to the edge of the flange to define a pull tab so that lifting of said tab and the application of force thereon tears the sealing sheet along its lines of weakness and leaves the closure hinged to the side of the container opposite the pull tab.

2. A full opening end closure construction for the mouth of a multiple sided container having rigid side walls comprising: a ledge integral with the side walls of the container and spaced down from the end thereof, said ledge Extending entirely around the inner periphery of the mouth of the container; an insert of a size to fit snugly into the mouth of the container so as to rest on said ledge; a thin, flexible sealing sheet adhered to the underside of said insert and projecting beyond the edges of the insert; a repeatedly effective pressure sensitive adhesive on the underside of side wall surfaces, and the repeatedly effective pressure sensitive characteristics of the adhesive on the underside of the sealing sheet enabling reclosing of the container mouth after initial opening; side flanges on said sealing sheet folded over the adjacent portions of the sides of the container; and repeatedly effective pressure sensitive adhesive on the undersides of said flanges by which they are adhered to the side walls, said thin sealing sheet being weakened at the junctures of the side flanges to the sheet proper along all but two opposite sides so that one of said unweakened sides provides a hinge for the closure while the flange opposite thereto provides a pull tab so that the application of force thereon tears the sealing sheet along its lines of weaknes and leaves the closure hinged to the sides of th container opposite the pull tab.

LEWIS C. BROOKS.

flle of this patent:

UNITED STATES PATENTS Number Name Date 1,497,159 Porter June 10, 1924 1,859,523 Neely May 24, 1932' 1,915,503 Schmidt June 27, 1933 1,992,152 Yeates Feb. 19, 1935 2,345,486 Leebov Mar. 28, 1944 2,369,975 O'Brien Feb. 20, 1945 2,381,508 Moore Aug. 7, 1945