US3445023A - Container lid - Google Patents

Description

y 20, 1969 V D. A. GIESSLER ET AL 3,445,023

CONTAINER LID Original Filed June 29, 1964 ..IIIIIIII INVENTOR.

DONALD A. GIESSLER BY LAURENCE [.LAFFERT JR.

United States Patent CONTAINER LID Donald A. Giessler, Muncie, and Laurence E. Lalferty, Jr., Yorktown, Ind., assignors to Ball Brothers Company Incorporated, Muncie, Ind., a corporation of Indiana Continuation of abandoned application Ser. No. 534,600,

Feb. 8, 1966, which is a continuation of abandoned application Ser. No. 378,651, June 29, 1964. This application Apr. 12, 1967,Ser. No. 630,461

Int. Cl. B65d 23/00, 53/02, 45/32 US. Cl. 215-40 4 Claims ABSTRACT OF THE DISCLOSURE A lid for use on home canning containers. The lid consists of a central portion, a rim and a short skirt. A gasket of vinyl plastisol is disposed on the interior side of the rim and the skirt extends at an obtuse angle with respect to the rim whereby the skirt is prevented from hanging on the forming shoulder of a glass container which would prevent the lid from sealing the container.

This application is a continuation of copending US. application Ser. No. 534,600, filed Feb. 8, 1966, entitled Container Lid, by Donald A. Giessler et al., and now abandoned; which application in turn was a continuation of application Ser. No. 378,651, filed June 29, 1964, entitled Container Lid, by Donald A. Giessler et al. and now abandoned.

This invention relates to a new and improved container lid and more particularly relates to a lid of the type employed with home canning containers.

In one widely used home canning system, a lid is placed on a jar filled with food, and a threaded cap or band is tightened onto the jar to hold the lid in contact with the upper surface of the jar. The closed jar is then heated to process the food therein. During the heating step, the vapor pressure inside the jar increases causing excess vapor to vent from the jar. After the heating period, the jar containing the food is cooled reducing the pressure inside the jar to subatmospheric pressure. This partial vacuum forces the lid tightly against the jar opening and seals the food inside the jar.

One of the problems with home canning lids employed heretofore was that the lids did not properly seal onto the finish or upper surface of the jar. The sealing problem is particularly significant because the jars employed in many cases have been used for a large number of canning operations and as a result may have defects or other damage to an extent which would cause rejection if the jars were inspected by the standards employed for new jars. Another important factor is the variability in processing procedure as it is conducted by the large number of home canners throughout the country. Thus, it is evident that home canning lids are subjected to a much greater variation in operating conditions than normally would be encountered by commercial closures but still must have sealing characteristics which will permit the home canner to achieve a high degree of success under the variabilities inherent in the process.

Attempts were made to overcome the deficiencies of previous lids by modifying the lids in various ways such as by changing the gasket material. However, it was found, for example, that when a cellular vinyl plastisol gasket material was tried, the sealing performance was less successful rather than being improved.

In view of the above and other deficiencies and shortcomings of home canning lids heretofore proposed, it was completely unexpected and surprising to discover a ice new and improved lid which overcomes many of the difficulties encountered with previous lids. The lid of the invention provides excellent sealing characteristics while providing a satisfactory level of other performance characteristics. The lid of the invention is also particularly useful with vinyl plastisol gasket materials. Furthermore, the lid of the invention provides satisfactory venting and removal characteristics without adversely affecting the sealing performance of the lids. In addition, the lid design of the invention facilitates application of the lid to the container and provides easy seating of the lid on the finish of the container.

Other advantages and benefits of the invention will be apparent from the following description and drawings, in which:

FIGURE 1 is a side elevation partially in section of a lid of the invention;

FIGURE 2 is an enlarged fragmentary section of the rim portion shown in FIGURE 1; and

FIGURE 3 is a side elevation showing the lid positioned on the finish of a jar.

As shown in the drawing, a lid 11 has a dome portion 12 with a surrounding ring portion 13. The ring portion 13 has a raised rim portion 14 which is connected to the dome portion 12 by an upwardly extending annular shoulder portion 15. The periphery of rim portion 14 has a downwardly extending skirt or flange portion 16. Within the cavity formed by portions 14, 15, and 16 is disposed a gasket material 17.

The shoulder portion 15 and the skirt portion 16 extend downwardly from the rim portion 14 in a divergent relationship and at an obtuse angle to the ring portion. Advantageously, the angles of divergence of the shoulder and the skirt from the rim are substantially equal and preferably an obtuse angle less than about and particularly between about 92 and 98.

The depth of the skirt portion 16 is substantially less than the depth of the shoulder portion 15. Advantageously, the skirt portion extends a vertical distance about one-half that of the shoulder portion, that is between about onethird and two-thirds. In addition, it is advantageous for the skirt portion to have a depth less than about two times the depth of the gasket material in the ring portion 13. Preferably, the depth of the skirt portion is between about 0.04 and 0.08 inch and particularly between about 0.05 and 0.07 inch. For example, when the gasket material has a depth of 0.03 inch, the skirt portion advantageously has an overall depth of about 0.06 inch.

As shown in FIGURE 3 of the drawing, in the use of the lid of the invention, the lid 11 is positioned on the upper sealing surface or finish 19 of a jar 20. The upper surface 19 in conventional home canning jars meets the vertical sidewalls 21 of the jar in a curved portion 22. However, due to the processes employed in forming the jars, a thin shoulder portion 23 is formed at the point at which the sealing surface 19 meets the sidewalls 21. While the shoulder 23 results in efliciences in the formation of the glass, the shoulder 23 creates problems in the seating of the lid on the sealing surface. However, the design of the lid of the invention facilitates seating of the lid on the finish of the jar without adversely affecting the sealing characteristics of the lid in the canning operation.

During the canning operation, a suitable band 24 is positioned over the lid and threaded onto the thread portions 25 of the jar. The jar containing food with the lid and band secured thereto is placed into a steam or hot water chamber to process the food. During the heating step, the vapor pressure inside the jar increases which vents the excess pressure from the jar. After the heating step, the jar is removed from the heating media and permitted to cool. During the cooling, the vapor pressure in the jar drops below atmospheric pressure with the result that the pressure differential between the atmosphere above the lid and the reduced atmosphere inside the jar causes the lid to be forced against the jar finish or sealing surface 19 so that the gasket portion 17 of the lid seals against the finish of the jar. Since the lid 11 is tightly sealed to the jar, the band 24 may be removed and reused in combination with other lids.

The lid design of the invention advantageously also includes a raised central portion (not shown) in the dome portion 12 of the lid. This raised central portion provides an audible snap down of the dome portion under vacuum which indicates to the canner that a proper seal has formed.

The lids of the invention may be formed by suitable metal-forming operations. Advantageously, the lids are formed in a single operation. Since the coatings applied to the top and undersurface of the lid are highly flexible and adhere tightly to the tinplate used in the formation of the lid, the tinplate may be coated prior to the formation of the lid without fracturing of the coating during the forming operation.

Advantageously, a protective coating is applied to the undersurface of the lid which contacts the food stored in the jar. Preferably, this coating is an epoxy resin which may be combined with a pigment such as titanium dioxide and other ingredients such as driers, solvents, lubricants, and the like.

The gasket composition may be formed from a natural or synthetic rubber solution or emulsion or more advantageously from a vinyl plastisol composition. The gasket composition preferably includes suitable fillers and emulsifying agents. The gasket composition is advantageously applied to the annular ring portion of the lid by spreading a thin coating of the composition in the groove of the rim portion and thereafter heating the lid to change the gasket to its finished form.

The above description shows that the lid of the present invention provides a combination of advantages and benefits which were heretofore unobtainable. .For example, the lid design of the invention facilitates seating of the lid on the finish of a jar without adversely affecting the sealing characteristics of the lid. Furthermore, the lid provides excellent sealing characteristics during extended storage periods and provides satisfactory venting and removal performance. In addition, the lid provides excellent results with vinyl plastisol gasket materials. Such a combination of advantages was not obtainable by any of the previously employed lids.

It will be apparent from the above description and drawing that various modifications in the lid construction described above may be made within the scope of the invention. Therefore, the invention is not intended to be limited to the specific details described herein and shown in the drawing except as may be required by the following claims.

What is claimed is:

1. In a packaging unit of the type which includes a rigid container having an opening, a sealing surface in substantially the same plane as said opening, an externally extending shoulder portion substantially parallel to said sealing surface and spaced a short distance therefrom, and a portion connecting said sealing surface and said shoulder portion, the improvement in said packaging unit of a lid for use with said container, said lid having a cover portion with a rim, a relatively thick plastisol gasket material disposed over the interior side of said rim so as to engage said sealing surface when said lid is in a position to cover the opening of said container, and a skirt portion extending from the periphery of said rim at an obtuse angle measured from the interior side of said rim, said skirt portion being of a depth greater than the depth of said gasket material but not greater than about twice said depth and said obtuse angle being such that said skirt portion is contiguous to said shoulder portion but free to move therepast so that sealing of said container by said lid is unhindered by said shoulder portion of said container.

2. In a packaging unit of the type which includes a rigid container having an opening, a sealing surface in substantially the same plane as said opening, an externally extending shoulder portion substantially parallel to said sealing surface and spaced a short distance therefrom, an inwardly extending shoulder portion comparable to said externally extending shoulder portion, and portions connecting said sealing surface and each said shoulder portion, the combination with said container of a lid having a cover portion including a center portion, a rim, and an annular shoulder connecting said center portion and said rim, said annular shoulder extending from the inner edge of said rim at an obtuse angle measured from the interior side of said rim, a relatively thick plastisol gasket material disposed over the interior side of said rim so as to engage said sealing surface when said lid is in a position to cover the opening of said container, and a skirt portion extending from the periphery of said ri-m at an obtuse angle measured from the interior side of said rim, said skirt portion being of a depth greater than the depth of said gasket material but less than the depth of said annular shoulder of said cover portion, and said obtuse angle being such that said skirt portion is contiguous to said shoulder portion of said container but free to move therepast so that sealing of said container is unhindered by said shoulder portion of said container.

3. In a packaging unit of the type which includes a rigid container having an opening, a sealing surface in substantially the same plane as said opening, an externally extending shoulder portion substantially parallel to said sealing surface and spaced a short distance therefrom, an inwardly extending shoulder portion comparable to said externally extending shoulder portion, and portion connecting said sealing surface and each said shoulder portion, the improvement in said packaging unit of a lid for use with said container, said lid having a cover portion including a center portion, a rim, and an annular shoulder connecting said center portion and said rim, said annular shoulder extending from the inner edge of said rim at an obtuse angle measured from the interior side of said rim, a relatively thick cellular vinyl plastisol gasket material disposed over the interior side of said rim so as to engage said sealing surface when said lid is in a position to cover the opening of said container, and a skirt portion extending from the periphery of said rim at an obtuse angle measured from the interior side of said rim with said obtuse angle being substantially equal to that measured between said annular shoulder and said rim, and said skirt portion being of a depth greater than the depth of said gasket material but less than the depth of said annular shoulder of said cover portion and said obtuse angle being such that said skirt portion is contiguous to said shoulder portion of said container but free to move therepast so that sealing of said container is unhindered by said shoulder portion of said container.

4. In a packaging unit of the type which includes a rigid container having an opening, a sealing surface in substantially the same plane as said opening, an externally extending shoulder portion substantially parallel to said sealing surface and spaced a short distance therefrom, an inwardly extending shoulder portion comparable to said externally extending shoulder portion, and curved portions connecting said sealing surface and each said shoulder portion, the combination with said container of a lid having a cover portion including a center portion, a rim, and an annular shoulder connecting said center portion and said rim, a cellular vinyl plastisol gasket material disposed over the interior side of said rim so as to engage said sealing surface when said lid is in a position to cover the opening of said container, and a skirt portion extending from the periphery of said rim at an obtuse angle meausred from the interior side of said rim, said skirt por- 5 6 tion being of a depth not greater than twice the depth References Cited Of Saidgasket mat-Bria]. and obtuse angle being Such that said skirt portion 15 contiguous to said shoulder portion but free to move therepast so that sealing of said 2,449,014 9/1948 Shafier X container by said lid is unhindered by said shoulder por- 2,700,186 1/1955 Stove! 215-40 X tion of said container, said annular shoulder extending 5 3,018,911 1/1962 GrPmbles et a1 21540 from the inner edge of said rim at an obtuse angle 3,202,307 8/1965 Ramer et a1 21540X measured from the interior side of said rim with said obtuse angle being substantially equal to that measured DONALD NORTON Pnmary Examiner between said skirt portion and said rim, and said skirt por- 10 U S C1 X R tion extending a distance between one-third and two-thirds that of said annular shoulder of said cover portion. 215-31, 97

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