US3720347A

US3720347A - Packaging container

Info

Publication number: US3720347A
Application number: US00207316A
Authority: US
Inventors: K Stoffregen
Original assignee: Schmalback Lubeca AG
Current assignee: Ardagh Metal Beverage Germany GmbH
Priority date: 1970-12-18
Filing date: 1971-12-13
Publication date: 1973-03-13
Anticipated expiration: 1990-03-13
Also published as: GB1380076A; DE2062412B2; DE2062412A1; CA957323A

Abstract

A container of the type wherein a removable sealing ring is positioned between a container body and a closure member and forms a seal therebetween. The container has been improved to prevent leaking during cooling following heating to sterilize at which time a vacuum exists within the container by providing a second seal which is effective only when there is axial telescoping displacement of the closure member relative to the container body as may occur when a vacuum exists.

Description

lln'ited StiltES Patent 1 1 Stoffregen [s41 PACKAGING CONTAINER [75 lnventor: Karl Heinz Stoftregen, Braunschweig, Germany [731' Assignee: Schmalback-Lubeca-W erke Aktieng'esellschait, Braunschweig, Germany 22 Filed: Dec. 13, 1971 21 Appl. No.: 207,3l 6 Foreign Application Priority Data Dec. 18. 1970 Germany ..P 20-62 412.8

[52] US. Cl. .i....220/46 R, 220/47, 215/46 R [51] Int. Cl. ..B65d 53/00 58] Field of Search ..220/46, 47; 2l5/40, 46

[56] References Cited UNITED STATES PATENTS 3,460,709 8/1969 Biederetal "220747 1March 13, 1973 3,378,163 4/1968 Griffith ..220/47 Primary Examiner--George T. Hall AttorneyCharles E. Brown et al.

[ ABSTRACT A containerof the type wherein a removable sealing ring is positioned between a container body and a closure member and forms a seal therebetween. The con- 9 Claims, 2 Drawing Figures for the purpose of opening the container.

BACKGROUND OF THE INVENTION First of all, it is to be understood that broadly speaking such containers are well known.

Two essential functional premises for the successful use of the packaging containers of the aforementioned type are the hermetic sealing and the availability of easy opening by pulling out the sealing ring from betw een the lid and the body of the container. Both characteristics are closely interrelated, since for the achievement of an optimum seal a solid closing engagement as between the body, the sealing ring and the lateral surface of the lid is necessary, which solidengagement in tern makes the pulling out of the sealing ring and thus the opening of the container difficult whenever it is too firm. Therefore, both factors must be balanced out one against the other.

Special care rnust be given to the problem ofthe seal whenever it is a matter of. using the packaging container of the initially described type as containers for preserved goods. As is well known, a container during the sterilization process and subsequent cooling is subjected to variable stresses. For example, during boiling, as a part of the sterilization process, there develops within the container an excess pressure which must'be countered. There is also a high external pressure phase experienced in the customary autoclave. Further, there is a breaking limit resistance on the part of the container, This breaking limit resistance is determined by the previously mentioned closing shape.

During cooling, after the boiling for sterilization, a vacuum develops in the container which likewise must be resisted by the container on the basis of its constructlon.

In thecase of known embodiments of this type of packaging containers, the flanged edge of the lateral surface of the lid has been rolled in the form of a hook, sincethe flanged edge serves the purpose of holding the sealing ring through clamping, and for which purpose the free edge of the flanged edge is driven into the sealmg ring.

In the past this driving in of the hook shaped flanged edge into the annularbody of the sealing ring and the connectionof the body with the lid brought about as a result thereof, has taken place prior to placing the lid onto the can. 'Apart from the fact that for such an attachment of the sealing ring to the lid requires a special work step which, because it is so complicated, can hardly be accomplished mechanically or by machine, it has been found that during-the subsequent closing of the container in the caseof bending the lateral surface of the lid toward the body of the-container, necessarily a compression and buckling of the sealing ring takes place. This leads to difficulties in the area of the rolled in this area because, otherwise, it will not be possible to pull out the ring. The sealing ring therefore in this area is not guided and held with the necessary assurance. These known embodiments cannot be used successfully as containers for preserved goods, since they will not sufficiently withstand the previously mentioned breaking pressure and also since they will not remain hermetically sealed after sterilization. The hook shape or open development of the edge flange has proven to be unfavorable in this respect, particularly in that the precise area of the edge of the lid is a critical one with respect to the bursting pressure, and that, therefore, the danger of a bending up of the lid and thus of a loss in tightness of the container seems to be impossible unless there is a sufficient reinforcement of this area, for which an open edge flange is not sufficient. With this arrangement, it has also been found that these containers cannot be opened easily, since the edge flange of the lid, having been driven into the sealing ring, will strongly resist being pulled upQMoreover, these known embodiments of this type of' container lack the possibility for stacking and unstacking of the lids, which is important for an automatic closing process, since the sealing rings clamped into the edge flange will impede stacking.

Previously, a proposal has been made, in order to avoid the above mentioned disadvantages, to develop the edge flange of the lateral surface of the lid bent toward the body of the container so as to be practically closed within itself so that the lid will fit against the sealing ring only through the surface facing the body of the container and that it will deform said sealing ring. With this development, it was intended to achieve a particularly good stability of shape which will withstand even substantially high bursting pressures developing during sterilization. Undoubtedly, an additional advantage of this arrangement resides in that the container can be opened easily by means of the gripping tongue in order to remove its contents since the sealing ring can slip down without any essential resistance from the surface of the edge flange facing the body of the container and particularly because there is no sharp edge directed against the surface of the sealing ring in an impeding manner.

Exhaustive experiments, particularly in connection with the use of packaging containers of the aforegoing type, as containers for preserved goods that do not need refrigeration resulted in the fact that a reliable use in this field does not result despite satisfactory results with regard to resistance to breaking pressure and the possibility of opening by means of pulling out the sealing ring. Indeed, it turned outthat the vacuum seal which is extremely important for the durability of the canned goods, within the framework of cooling after boiling for sterilization, is not reliable in the case of containers developed in that way. It was found that during cooling and formation of the vacuum inside the container, contamination occurred through the water in the autoclave, which took place as a result of the fact that this water was sucked in, in the manner of a capillary, into the border area between sealing ring and body and the wall of the lid. The closing shape of the wall of the body, the sealing ring and the lateral surface of the lid could not prevent this contamination by water of the autoclave. In this case the area of the fit of the sealing ring against the longitudinal seam of the body is particularly sensitive.

SUMMARY OF THE INVENTION It is the object of the invention to find some way to prevent the aforementioned deficiencies. Consequently the present invention proposes to create a packaging container of the initially described type which, besides having optimum resistance against breaking pressure, with a simultaneous ease pulling out the sealing ring in order to open the container, will still have the necessa ry vacuum seal and consequently the changing pressure conditions in the packaging container are fully taken into account during pressure changes encountered in the sterilization process'passing from boiling to cooling, and thus makes possible a reliable use of the container for refrigerated and non-refrigerated canned goods.

According to the invention, the object will be achieved through the fact that the lateral surface of the lid in the area of the edge flange of the container has a groove provided with elastic sealing means, whose dimension corresponds approximately to the size of the edge flange of the container. Through this characteristic one will achieve during cooling after boiling as part of the sterilization process and while forming a vacuum inside the container, that the lid is pulled hard against the body of the container in the direction of the longitudinal axis, whereby the flange of the edge of the container moves in the groove, forcing itself into a positive and shaping sealing engagement with an elastic sealing means of the groove. As a result of that, one will achieve a very greatly improved seal in this area, which will make it impossible for water from the autoclave to be pulled inside the container. The packaging container of the initially described type developed in this way thus can be reliably used for containers for refrigerated and non-refrigerated preserved goods.

According to a further characteristic of the invention, the end panel of the lid is provided with a conventional grooved or cooking profile. This development, which is customary in the case of standard containers for preserved goods closed by way of a solid folding border, is of advantage within the scope of the present invention in that it provides for the resiliency of the lid during sterilization.

In order to obtain an improved penetrating depth and simultaneously a particularly smooth fit of the flange of the edge of the container within the sealing means of the groove, in the case of formation of a vacuum and during cooling, the sealing means is provided with additives causing a swelling.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawing:

In the drawing:

FIG. 1 is an enlarged fragmentary vertical sectional view through the upper part of the closed packaging container according to the invention either before or during boiling for sterilization purposes.

FIG. 2 is a view similar to FIG. 1 showing a slightly modified form of the container during cooling while a vacuum develops inside the container.

Referring now to the figures of the drawing, there is illustrated a body I of the container, preferably formed of sheetmetal, whose upper edge terminates in a flange 2 reversely turned toward the exterior of the body 1. Immediately below the flange 2 of body 1 of the con tainer the string-like elastic sealing ring 3, which is continuous, is put under pre-tension onto the body I of the container, which sealing ring can be pulled out by means of an integral gripping tongue 4 provided on it in a position to project from between a lid and the body of the container. In order to prevent a slipping of sealing ring 3 during the closing of the container, the ring has been fixed on the body of the container. With this invention, this is accomplished by means of a bead 5 protruding toward the outside of the body 1 of container, against which the sealing ring 3 seats from above. This type of fixation of the ring is preferred in the case of so-called three piece containers where the bottoms of said containers are formed and secured to the body separately. It is also possible to arrange, instead of the circular bead 5, several point-like cams, etc., which lie at the same level and are distributed over the periphery of the body 1 of the container. The cross section of sealing ring 3 can be selected as desired. However, sealing rings with a round or oval cross section are preferred.

A lid 6 serves as a closing element and has a chuck wall 7 which fits against the inside of body 1 of the container in the upper area thereof, and an end panel 8 which has a conventional grooved or cooking" profile known. The chuck wall of lid 6 terminates in a lateral surface 10 via a channel 9 constituting the essential characteristic of the invention. As can be seen from the figures of the drawing, channel 9 is formed in the preferred embodiment as an arch extending from the chuck wall 7 and terminating at a step 1 l which slightly interrupts the continuous course of the lateral surface 10 from the chuck wall 7. Channel 9 of lid 6 has a traverse extent of a magnitude which corresponds approximately to the size of the flange 2 of the container and is filled with a resilient sealing means 12.

As can be seen furthermore from the figures of the drawing, the lateral surface 10 of lid 6 is bent in a direction toward body 1 of the container in a conventional manner and fits against the sealing ring 3 in a manner generally deforming the sealing ring. The end of lateral surface 10 of lid 6 preferably will have an approximately eliptical shaped edge flange 13, as has been shown in FIGS. 1 and 2. This edge flange has the advantage that it will facilitate the pulling out of the sealing ring 3 in order to open the container, since the sealing ring 3 will thus not be hold back by any sharp edge. If desired, the edge flange 13 may be omitted and the end of lateral surface 10 of lid 6 can have approximately the shape shown in FIG. 1. It will be apparent that the lateral surface 10 of lid 6 embraces the sealing ring 3 and holds it firmly in the necessary manner with a slight deformation.

As is apparent from FIG. 1, channel 9 filled with the sealing agent 12 lies in the closed state of the container, as well as prior to the sterilization process and also during boiling for sterilization, at a distance above the flange 2 of body 1. The sealing in this phase is accomplished exclusively by the closing shape of body 1 with the sealing ring 3 and of the lateral surface 10 of lid 6.

nection with it, the more or less ease of pulling out the sealing ring 3 in order to open the packaging container to withdraw the goods from it is determined in this case by the fit or contour of lateral surface of lid 6.

As already mentioned, the cooling after boiling for sterilization brings about the formation of a vacuum inside the container. As a result, lid 6 is drawn downwardly from the position of FIG. 1 into the position of FIG. 2. At the same time, the flange 2 of body 1 moves into channel 9 of lid 6 and embeds itself firmly in sealingagent 12 and there forms a hermetic vacuum seal. in connection with this, the grooved or cooking profile of the end panel 8 of the lid acts in a known manner. It thus is impossible for water from the autoclave, for example, to penetrate in the manner of capillaries between the body engaging surface of sealing ring 3 on the one hand and the outside wall of body 1 or between the inside wall of lid 6 and the sealing ring into the inside of the container.

The embedding of flange 2 of body 1 into the sealing agent 12 ofchannel 9 still can be improved by providing the sealing agent 12 with conventional additives causing a swelling.

The present invention is not limited to use and utilization of a.compact sealing ring 3 of the shape shown in the drawing. Rather, the invention can be applied even in those cases where, for example, a sealing ring is used with essentially the same shape of the packaging container, which sealing ringis injected in a liquid state into the area between the body and the lid and where it subsequently hardens.

Although only a preferred embodiment of the invention is specifically illustrated and described herein, minor variations may be made in the container closure construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A container comprising a container body open at one end, and a closure assembly closing said one end, said closure assembly including an outwardly directed peripheral projection on said body at said one end, a closure member, said closure member having an inner portion seatedwithin said body one end and an outer peripheral flange spaced from and surrounding an end portion of said container body, and an elastic sealing ring tightly surrounding said container body below said peripheral projection, said sealing ring being compressively deformed between said container body and said peripheral flange and being interlocked with said peripheral flange to both seal and prevent axial removal of said closure member, said closure assembly further including a peripheral channel integrally connected between said closure member inner portion and an outer peripheral flange, said peripheral channel being axially aligned with said peripheral projection and having therein an elastic sealing agent for sealing engagement with said peripheral projection.

2. A container in accordance with claim 1 wherein said sealing agent includes additive means for effecting a swelling of said sealing agent.

3. The container of claim 1 wherein said sealing agent is normally axially spaced from said peripheral projection and becomes ogerative only when said closure member 15 depresse relatlve to said container body such as when a vacuum exists within said container.

4. The container of claim 3 wherein the spacing of said sealing agent relative to said peripheral projection is normally maintained by said sealing ring.

5. The container of claim ,3 wherein the spacing of said sealing agent relative to said peripheral projection is normally maintained by said sealing ring, said container body having a second outwardly directed peripheral projection spaced below the first mentioned peripheral projection, said sealing ring being seated between said peripheral projections and axially positioned thereby, and said closure member outer peripheral flange being interlocked with said sealing ring.

6. The container of claim 5 wherein said container body is formed of metal and said first mentioned peripheral projection is in the form of a curl and said second peripheral projection is in the form of a bead.

7. The container of claim 1 wherein said container body is formed of metal and said peripheral projection is in the form of a curl.

8. The container of claim 1 wherein said sealing ring is of the pull-out type for facilitating the opening of said container and has a pull tab.

9. The container of claim 1 wherein said closure member includes a chuck wall tightly nested within said container body, and an end panel extending across said chuck wall and connected thereto, and said endpanel has a cooking profile.

It! l i l

Claims

1. A container comprising a container body open at one end, and a closure assembly closing said one end, said closure assembly including an outwardly directed peripheral projection on said body at said one end, a closure member, said closure member having an inner portion seated within said body one end and an outer peripheral flange spaced from and surrounding an end portion of said container body, and an elastic sealing ring tightly surrounding said container body below said peripheral projection, said sealing ring being compressively deformed between said container body and said peripheral flange and being interlocked with said peripheral flange to both seal and prevent axial removal of said closure member, said closure assembly further including a peripheral channel integrally connected between said closure member inner portion and an outer peripheral flange, said peripheral channel being axially aligned with said peripheral projection and having therein an elastic sealing agent for sealing engagement with said peripheral projection.

3. The container of claim 1 wherein said sealing agent is normally axially spaced from said peripheral projection and becomes operative only when said closure member is depressed relative to said container body such as when a vacuum exists within said container.

5. The container of claim 3 wherein the spacing of said sealing agent relative to said peripheral projection is normally maintained by said sealing ring, said container body having a second outwardly directed peripheral projection spaced below the first mentioned peripheral projection, said sealing ring being seated between said peripheral projections and axially positioned thereby, and said closure member outer peripheral flange being interlocked with said sealing ring.