US2529644A - Expansible closure for containers - Google Patents

Description

Nov. 14, 1950 R. .c. WEBBER EXPANSIBLE CLOSURE FOR CONTAINERS Filed April 11, 1945 INVENTOR. 1905527 6. l f/e,

Patented Nov. 14, 1950 UNITED STATES PATENT OFFICE EXPANSIBLE' CLOSURE FOR CONTAINERS Robert C. Webber, Indianapolis, Ind.

Application April 11, 1945, Serial No. 587,659

1 Claim.

The present invention relates to container closures, and its primary object is to provide a novel form of closure for receptacles primarily intended to contain food in frozen storage. It is well known that food to be so preserved should be enclosed in some sort of moisture proof containers before being deposited in the freezer, and that it is highly desirable to prevent movement of air in contact with the food. Some types of food can be reasonably well preserved by wrapping in paper, parchment or the like, but other types of food, it is found, must be enclosed in glass or metal containers for best results. Most known forms of closures for such receptacles, which are capable of producing a really tight closure of the container, are of such character that the closure, or the container, or both, will usually be seriously damaged, if not destroyed, by the operation or" removing the closure. The sealing effect of the closure must be quite strong, because the reducs tion of temperature of. the contents of the receptacle will, of course, cause a contraction of the gases within the container so that the internal pressure falls materially below the atmospheric pressure surrounding the receptacle in the freezer, whereby a pressure diiferential tending to cause leakage of air into the receptacle is produced.

I have conceived a closure element of such character that the very reduction of temperature, incident upon placing the receptacle and closure in a freezer chamber, causes an auto matic action of the closure member which will produce a tight seal between the closure and the receptacle.

To the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope of the appended claim is not violated.

Fig. l is a more or less diagrammatic elevation of a receptacle designed for cooperation with my closure member, part of the receptacle being broken away for clarity of illustration of the closure member shown, in solid lines, in sealing relation with the receptacle, and. in dotted lines in non-sealing relation therewith;

Fig. 2 is an enlarged fragmental sectional view of a portion of the closure element in nonsealing relation with a corresponding portion of the receptacle;

Fig. 3 is a view similar to Fig. 2 but showing the parts in sealing relationship;

Fig. 4 is an enlarged fragmental illustration of a modified form of closure member in non-sealing relation with a modified form of receptacle; and

Fig. 5 is a view similar to Fig. 4 but showing the parts in sealing relation.

Referring particularly to Figs. 1 to 3 inclusive, my novel closure member is indicated generally by the reference numeral l0. body substantially in the form of a double con, vex disc, the oppositely associated portions Ii and 12 thereof being joined at their perimeters to produce a relatively sharp edge l3. This body is filled with a material having a high coefiicient of expansion in response to temperature changes within the range between zero degrees F' and '10 degrees F., for example. Numerous such materials are known, the critical characteristic being that a change of temperature of such material from room temperature, for instance, to atemperature below 25 degrees F., for instance, shall make a very substantial reduction in the volume occupied by such material at atmospheric pressure. One such material is ammonia, and another is dichlorodifluoromethane.

The body I!) must be fluid tight and must be made of material which is stifily flexible. Sheet steel of a thickness from .015" to .10", for instance, will operate satisfactorily; and many of the more flexible plastics will react in the manner required to carry out my invention. It is to be understood that the above suggestions are illustrative, rather than limitative. The material used must be of such character that, as the volatile substance within the body NJ expands and contracts, the central regions of the portions H- and i2 of the body I!) will be separated by internal pressure, or moved toward each other by atmospheric pressure. Obviously, such movement of the central regions of the two portions of the. body H] will result in reduction and expansion, respectively, of the perimetral dimensions of the body H3 at the edge l3.

Preferably, but not necessarily, the volatile substance enclosed within the body It will be of such character that. it will undergo a phase change from gas to liquid as its temperature varies between room temperature and, for instance, zero degrees F. Materials having such characteristics include dichloromonofluormethane, ethyl chloride, and butane. Such a phase change will, of course, materially exaggerate the variations in the volume occupied by the entrapped material, at atmospheric pressure, during, temperature changes.

I have stated that the body ID will preferably take the form of a double convex disc, It will be obvious that said body need not be circular in perimetral contour, but that it may take any It comprises a regular polygonal form. If, for instance, the perimetral contour of the body I is rectangular, the portions II and I2 will be substantially pyramidal, rather than conical or part-spherical. The manner of operation, however, will remain the same no matter what is the perimetral contour of the body I0.

Such a closure body will operate to produce a reasonably satisfactory seal with any receptacle whose internal perimetral contour corresponds to the perimetral contour of the closure body, and Whose internal diametrical dimension is within the range of dimension variations of the body I0. I prefer, however, to associate the body ID with a specially designed receptacle.

Such a receptacle is illustrated at I4 in Figs. 1, 2 and 3, and a portion of such a receptacle is indicated at I4 in Figs. 4 and 5.

The receptacle I4 is preferably formed with an outwardly projecting bead near its open mouth, such bead being formed by an out-turned flange I5 with which is integrally joined an inturned flange I6 of less radial depth. The flanges I5 and I6, of course, cooperate to provide a perimetral, inwardly opening groove I I in the receptacle near the open mouth I8 thereof; but because of the difference in radial extent between the flanges I5 and IS, the flange I5 forms an inwardly projecting shoulder within the mouth I8 of the receptacle. Therefore, the body ID, in its condition illustrated in Fig. 2 and in dotted lines in Fig. 1, can be dropped into the receptacle and will pass through the neck portion I8 and come to rest upon the shoulder provided by the flange I5.

If, now, the receptacle and closure are placed in a freezer locker, or otherwis subjected to a reduction of temperature thereof, the gas within the body III will contract (passing through a phase change if a proper substance is selected) thereby reducing the pressure within the body It! and creating a pressure differential between the inside and the outside of said body. Since the atmospheric pressure exceeds the pressure within the body, as the temperature of the gas within the body is reduced, such atmospheric pressure will cause the central regions of the portions II and I2 of the body to approach each other, thereby forcing the edges of said portions II and I2 outwardly to increase the perimetral dimension of the edge I3 of the body I0. As the temperature drops lower and lower the edge I3 of the body It] will creep outwardly across the flange I5 until it tightly engages itself within the groove I7, as shown in Fig. 3.

In this relationship, the parts are inseparable, and a substantially hermetic seal is produced between the closure element Ill and the receptacle.

When the closed and sealed receptacle is removed from the refrigerating chamber and is allowed to stand for a short time in an atmospheric temperature of '70 degrees F. or thereabouts, the temperature of the volatile substance within the body II] will rise, whereby such substance will be caused to expand to overcome the tendency of the atmospheric pressure, and to separate the central regions of the body portions I I and I2, thereby reducing the perimetral dimension of th body II! to a point such that, eventually, the edge I3 will clear the neck I8 of the receptacle, and the body can be readily removed from the receptacle, without damage to the closure body or to the receptacle, and without the use of any tools or the application of any force to the assembled parts.

A modified shape of closure element and receptacle will be seen in Figs. 4 and 5. According to that embodiment of my invention, the body I0 comprises oppositely arranged portions II and I2 each of which has an inturned edge, as at and 2|, respectively. The two portions I I and I2 join at 22 at the base of the groove defined by the inturned portions 20 and 2f. The receptacle I4 is formed with an inwardly projecting bead 23 located in the neck 24 of the receptacle. It will be noted that the edge 25 of the portion I I of the body I0 extends radially somewhat beyond the corresponding edge 25 of the body portion I2. When the closure body I0 is at room temperature, the edge 26 thereof will clear the bead 23, while the edge 25 thereof will engage and rest upon said bead. When, however, the assembled elements are placed in a freezing cabinet, an action precisely like that above-described will take place, whereby the perimetral dimension of the body IE] will be increased, the edge 25 will creep outwardly over the upper surface of the bead 23, and the parts will attain the relationship illustrated in Fig. 5, wherein the receptacle is tightly sealed and the closure member ID is held against removal from the receptacle. To free the closure from the receptacle and permit its removal therefrom, all that is necessary is merely to allow the temperature of the assembled elements to rise sufiiciently to caus the volatile material enclosed within the body III to force the central regions of the portions II' and I2 apart, thereby reducing the perimetral dimension of the body IIl sufficiently to permit the edge 26 to pass the bead 23.

I claim as my invention:

The combination with a receptacle having an open mouth, of a closure for coaction with said receptacle mouth, one of said coacting elements being formed to provide a perimetral tongue and the other of said coacting elements being formed to provide a perimetrally extending groove in facing relation to said tongue and adapted to receive the same, said closure comprising a hollow, gas-tight body substantially in the form of a double convex disc and containing a fluid having a high coeflicient of expansion in response to tem perature changes in the range between 0 F. and F., said body being freely movable into and out of said receptacle mouth at room temperatures but being perimetrally expansible, upon substantial reduction in temperature, to engage said tongue in said groove, whereby said closure is held against removal from said receptacle mouth so long as such reduced temperature is maintained.

ROBERT C. WEBBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 20,388 Hoard May 25, 1858 547,224 McLaughlin Oct. 1, 1895 2,388,300 Wackman Nov. 6, 1945 2,389,534 OBrien Nov. 20, 1945 2,449,186 Wales Sept. 13, 1948 FOREIGN PATENTS Number Country Date 12,129 Great Britain 1915 281,312 Germany Dec. 30, 1914 507,616 Great Britain June 19, 1939 600,453 France Nov. 9, 1925

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