US3362565A

US3362565A - Container lid

Info

Publication number: US3362565A
Application number: US496550A
Authority: US
Inventors: Robert J Mccormick
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1965-10-15
Filing date: 1965-10-15
Publication date: 1968-01-09
Anticipated expiration: 1985-01-09

Description

Jan. 9,.1968 R. .1. MCCORMICK CONTAINER LID Filed Oct. 15. 1965 INVENTOR. I R0 6 er/ J MC Corm/lck QTTO/QNE Y5 United States Patent 3,362,565 CONTAINER LID Robert J. McCormick, Findlay, Ohio, assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware Filed Oct. 15, 1M5, Ser. No. 496,550 7 Claims. (Cl. 220-44) ABSTRACT OF THE DISCLOSURE A container and snap-on lid combination providing improved hermetic sealing and self venting features. The lid includes a vertical portion mating with a stacking shoulder of the container so that the lid is secured within the container. An inclined ring and other portions of the lid provide an easy escape path for the vented gases. Specifically, a sealing head of the lid includes notches extending into the bead a distance less than the entire depth thereof and into the vertical portion and inclined ring substantially the entire depth thereof which features accomplish the desired hermetic sealing and venting effects.

This invention relates generally to removable snap-on lids or closures for containers such as tubs for packaging cottage cheese, salads, ice cream and other products, and cups for coffee and soft drinks. More particularly, when the closure of the present invention is employed with such containers, a positive hermetic sanitary seal between the closure and the container is maintained at all times While the closure and container are in assembled relation and which, as occasion requires, simultaneously permits selfporting of gas from the container with the closure still maintained in a held relationship thereupon.

It has been customary of late for containers and lids of the type presently contemplated to be formed from plastic materials such as polystyrene of polyethylene, for example, wherein the container is of a one-piece seamless construction. Such a construction gives rise to the problem of making special provisions for the escape of any of the gas which may be generated by the particular food stuff packaged within the container. Without the provision in such a container of a venting or porting system, there would be a great likelihood of the lid being prematurely separated from the container by the force of the gas, of a crack occurring in the container, or an unsightly deformation thereof.

It is thus an object of the present invention to provide a novel lid for incorporation in a hermetically sealed fashion with a container, which lid permits the unidirectional escape of gas generated by the contents of the container while maintaining the lid in an assembled relation with respect to the container.

The present invention further contemplates a novel combination of elements permitting such a lid to have such highly desirable venting features along with advantageous stacking and removal qualities.

Briefly, the present invention comprises a lid which has a circumferential sealing head for engagement with a cooperating circumferential shoulder of a container, which bead contains spaced notches extending partly the width thereof whereby a fulcruming action of the center of the lid provides a passageway through the notches of the bead. Cooperating therewith is a secondary venting lug means for maintaining a channel-like spacing between the sidewall of the container and lid. Additional features of the lid are stacking bosses providing for an improved venting action at each of the venting passageways, and an extended lip forming said passageway and making possible exceptionally easy removal of the lid from its con tainer.

Yet additional objects and advantages of the present invention, and its numerous cognate benefits and features are even more apparent andmanifest in and by the ensuing description taken in conjunction with the accompanying drawing in which, wheresoever possible, like characters of reference designate corresponding material and parts throughout the several views thereof, in which:

FIGURE 1 is a top view of a container lid illustrating the principles of the present invention;

FIGURE 2 is an elevational View thereof;

FIGURE 3 is a bottom View thereof;

FIGURE 4 is an enlarged cross-sectional View thereof taken along the line 4-4 of FIGURE 1, with another container lid, shown in phantom, stacked therewith;

FIGURE 5 is an enlarged cross-sectional view thereof taken along the line 5-5 of FIGURE 1;

FIGURE 6 is an enlarged cross-sectional view thereof taken along line 6-6 of FIGURE 1, with a cooperating container rim, shown in phantom, sealed therewith; and

FIGURE 7 is a view like FIGURE 6 only with the container lid in a venting composure.

Referring now more particularly to the drawing, container lid or closure 10 is shown as comprising a center body portion 12, a fiat circular generally horizontal circumferential bead 14 connected therewith by a hinge ridge 15, a peripheral vertical portion 16 extending directly upwardly from the sealing bead, an inwardly inclined circumferential ring 18, a generally vertical sidewall 20, an outwardly projecting shoulder 22, and a generally inverted U-shaped rim 24 including an especially long skirt 26 forming .the outermost extent thereof, all successively joined to one another. Intermittently about sidewall 20 are angularly inwardly disposed embossments 28. Along inside wall 30 of rim 24 are located a plurality of outwardly projecting lugs 32 extending the full height thereof, and preferably located thereabout in spaced pairs.

The stacking feature of a plurality of lids 10, when located in a vertical arrangement one within the other, is illustrated in FIGURE 4 wherein the sealing head 14 of the uppermost lid rests upon

shoulders

22 and 22, shoulders 22' being an extension of the shoulder 22 occasioned by inwardly projecting embossments 28, the embossments 28 for this purpose presenting a greater horizontal surface area via shoulders 22 to provide for a more positive stacking, thus substantially eliminating any possibility of jamming.

In the engagement of a lid 10 with a container, such as container 34- (shown partially in phantom in FIGURE 6) sealing head 14 rests firmly and circumferentially upon shoulder 36 of the container so that it is impossible for air to penetrate into the tub through the engaged areas thereof. Located intermittently about sealing head 14, portion 16 and ring 18 are notches 38 extending from the outer circumference thereof inwardly to an extent les than the full width of sealing head 14. Thus, at least a hand area of bead 14 is circumferentially continuous about the lid. In the particular embodiment illustrated, notches 38 extend inwardly substantially the entire width of portion 16 and ring 18, thereby rendering portion 16 and ring 18 circumferentially discontinuous.

The function of the notches 38 is to provide a venting passageway 39 through which gases generated by the food contents packaged within the container can escape. An upward pressure, indicated by the arrows in FIGURE 7, is exerted by such gases upon the center body portion 12 of the lid 10. Such pressure gradually flexes the lid upwardly starting at its center causing a fulcruming action which progresses gradually outwardly toward sealing bead 14, lifting the bead upwardly from its inside extremity until the seal formed between the bead 14 and shoulder 24 is broken by notches 38. Such notches 38 when reached, by the lifting action of bead 14, provide the necessary passageways 39 for gases to escape. By employing such notches, sealing bead 14 can have a substantial width for over-all lateral contact with the shoulder 36, while permitting a relatively minor amount of gaseous pressure to break the seal formed thereby. The fulcruming action of the lid prompted by gas pressure build-up is aided by the natural hinge effect of ridge 15, which itself is in an inverted U- shaped circumferential configuration closely adjacent bead 14. Ridge 15 additionally facilitates mounting of lid 10 upon container 34.

Since sidewall 20 is spaced from container 36, each passageway 39 is naturally unrestricted from its extent from notches 38 through shoulder 22 to rim 24. The lugs 32 provide a continuation for passageways 39, substantially through the channel between pairs of lugs 32. Because the top of rim 24 and lip 26 are designed to be spaced from upper rim 40 of container 34, passageway 39 is completed to the outside of the container, the gas fiow being as indicated by the arrows.

Preferably, stacking embossments 28 and lugs 32 are located generally in line with the notches 38 to provide the easiest passageway 39 possible for the gaseous pressures generated within the container to escape. By employing embossrnents 28 and lugs 32 in such a cooperative arrangement, an especially Wide channel for the escaping gas is provided. Of course, once the gaseous pressure has been relieved, the fulcruming action provided by the gaseous pressure against the container center portion 12 will have dissipated and the sealing bead 14 will again press against shoulder 36 to provide a hermetically sealed package.

The long skirt 26 of lid 10 can easily be gripped with the fingers for pulling the snap-on lid 10 from the container when it is desired to have access to its contents.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

Accordingly, what is claimed as new is:

1. A container and a snap-in lid in hermetically sealed engagement therewith while permitting unidirectional porting of excess gaseous pressures generated by contents of said container, said container having a peripheral sidewall and an open end, an upper portion of the sidewall circumferentially offset radially outwardly relative to the lower portion of said sidewall to define a container shoulder, a vertically extending circumferential projection extending upwardly from said container shoulder, and an outwardly veering circumferential portion extending upwardly from said projection and ending in a peripheral rim at the open end of said container, said lid comprising an annular center body portion, a circumferential flat sealing bead located about the peripheral extent of said center body portion and received by said container shoulder, a vertical portion extending upwardly from said bead substantially parallel with the vertical projection of said container, a circumferential inwardly inclined ring, a circumferential upwardly extending portion generally opposite and spaced from the outwardly veering portion of said container, an outwardly projecting shoulder and a generally inverted U-shaped rim, all successively joined to one another, said bead being interrupted at its outermost extent by a plurality of spaced notches, said notches extending into said bead a distance less than the entire depth thereof and into said vertical portion and inclined ring substantially the entire depth thereof, said notches permitting said bead to have a band area which is circumferentially continuous and rendering both said vertical portion and inclined ring circumferentially discontinuous.

2. The lid of claim 1 wherein said upwardly extending portion comprises stacking embossments which are inwardly inclined from said side wall the entire height thereof adjacent each of said notches to increase the effective size of the passageway through which gases are to escape.

3. The lid of claim 2 wherein the remaining circumferential part of said upwardly extending portion is substantially vertically disposed.

4. The lid of claim 2 wherein lugs are located on the outside surface of the inside leg of said rim immediately above said notches to space said surface from said container providing an extension of said passageway.

5. The lid of claim 4 where said lugs are in pairs above each of said notches, the pair providing a channel therebetween.

6. The lid of claim 5 wherein a circumferential hinge joins said center body portion to said sealing bead.

7. The lid of claim 4 wherein the material comprising said lid is a thermoplastic resin.

References Cited UNITED STATES PATENTS 3,061,139 10/1962 Edwards 220--44 3,112,841 12/1963 Martinelli 220-44 3,173,571 3/1965 Cserny 220-44 THERON E. CONDON, Primary Examiner.

GEORGE E. LOWRANCE, Examiner.