CA1166190A

CA1166190A - Container, engagement ring and cover assembly

Info

Publication number: CA1166190A
Application number: CA000395699A
Authority: CA
Inventors: Charles R. Roper
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-04-20
Filing date: 1982-02-05
Publication date: 1984-04-24
Also published as: CA1166191A; JPS57194956A; JPS57194957A; US4356930A; JPH0139943B2

Abstract

CONTAINER, ENGAGEMENT RING AND COVER ASSEMBLY
Abstract of the Disclosure:
An upwardly open end portion of a plastic container straight sidewall is telescoped by an inverted U-shaped portion of a plastic engagement ring with a generally transverse, outward flange on the container sidewall snap interengaging with a similar engagement ring flange. An engagement ring U-shaped portion extends transversely inwardly having, in certain embodiments, either a simple or complex outer wall common with the inverted U-shaped portion and in all cases an interior wall spaced inwardly therefrom. An edge portion of a plastic cover overlies the engagement ring U-shaped portion and has a downward extension fitting therein divided into an exterior wall outwardly abutting the ring U-shaped portion outer or common wall and a transverse inward flange snap interengaging with a similar flange on the ring interior wall. The cover edge portion terminates inwardly at an interior wall which outwardly abuts the ring U-shaped portion interior wall and a cover transverse connecting part joins the edge portion interior wall vertically intermediate both the cover edge portion interior wall and the ring U-shaped portion interior wall. In the assembly, the engagement ring and cover are constructed to exert transverse pres-sure outwardly to outwardly abuttingly pressure seal between the cover edge portion and the engagement ring, and between the engagement ring and the container side-wall inner side. The cover edge portion terminates outwardly in a transverse flange spaced above the engagement ring and engageable by a tool for removing the cover from the engagement ring.

Description

~ 1~619~

Background of the Invention:
This invention relates to a ~ontainer, engagement ring and cover assembly which i~ constructed incorporating either one or both of two basic novel concepts,.either of which particularly adapt the assembly for preferably being molded totally of plastic. According to the one novel concept, an inverted U-shaped portion of the engagement ring telescopes over an open upper end of the container sidewall wi,th transverse inter-engagement between flanges thereof, and an edge portion of the cover overlies and extends downwardly into a U-shaped inward extension of the engagement ring with transverse interengagement between flanges thereof. In the other novel concept, an inve~ted U-shaped portion of the engagement ring telescopes an upper open end of the container sidewall positioning an engagement ring generally vertical wall outwardly abutting an inner side of the.container sidewalI and a generally ver~ical ~ 3 6 ~

wall on the cover edge portion is positioned outwardly abutting the engagement ring wall, with the engagement ring and cover being constructed and arranged to exert an outward transver~e pressure for pressure sealing 5. between the cover and engagement ring walls and between the engagement ring wall and the container sidewall inner side.
Various forms of prior container constructions have been hereinbefore provided involving a container, 10. engagement ring and cover assembly. Most of these particular prior constructions have been formed totally of metal, such as the u~ual tinplate. For instance, one of the prime examples is the common metal paint can in which paint and similar materials are commonly marketed 15. and used.
With the usual paint can, the container thereof is usually formed with a cylindrical sidewall having a bottom wall secured thereto by means of the usual multiple-folded ~eam commonly used in metal 20. containers and cans. An engagement ring is similarly multiple-fold seam secured to the upper open end of the container sidewall, the engagement ring extending transversely inwardly from the sidewall and being formed with a somewhat V-shaped annular recess spaced inwardly 25. from the container sidewall and extending around the same.

i 1 ~6 ~ ~3~

The cover has the edge portion thereof formèd with a reduced size, somewhat matching V-shaped recess proportioned such that the cover edge portion recess may be press-fit forced downwardly into the engagement 5- ring recess for thereby pressure sealing the contents of the container. Furthermore, a transversely projecting flange is formed at the periphery of the cover exposed for engagement by a tool to selectively remove the cover from its press-fit retention by the 10. engagement ring so that container contents may be used with the cover being capable of being returned to its assembled positioning and press-fit retainment due to the metal rigidity.
Beyond the foregoing purely functional 15. pressure sealing and containment feature~ of the prior paint cans and similar containers. such containers are required to have certain other particulars of construc-tion necessary for proper factory conveying and ultimate marketing. One of these is that the container 20. sidewall must be vertically straight throughout between the upper and lower end portion~ thereof. One of the principal reasons for this requirement is so that labeling may be conveniently applied thereto, whether by direct printing thereon or by adhesively applied 25. labels. If the container sidewall is other than straight, i~

1 1 66 ~ 90 obvious difficulties are presented.
Another requirement for convenience in convey-ing of the containers in the manufacturing facilities during filling, closing, packing and storage, and also 5- a~sociated with the straight container sidewall require-ment, is that the upper and lower end portions at the sidewall of the container must project transversely equal distances. In other words, once the engagement ring has been assembled with the container and both 10. before and after the assembly of the cover, the center axis of the container must be parallel to the surface upon which it rests when the container is laying on its side. This i8 necessary so that the container may be conveyed by rolling the same on its side during which 15. it must roll in a straight line.
As hereinbefore stated, most of the prior paint cans and similar containers incorporating container, engagement ring and cover assembly have been formed of metal and it has now been determined that if 20. this type of container could be constructed 80 that it is adaptable to being totally molded from plastic, quite extensive cost savings and other benefits could be appreciated in the manufacturing industries making use of this type of container. However, in order to 25. satisfactorily accomplish such conversion from total ~ ~ 66 ~ 9Q

metal to total plastic, the semi-as~embled and finally assembled plastic container would have to meet the exact same requirements as met by the prior metal container. To meet all of these re~uirements with a 5. molded plastic container pre~ents a multiplicity of problems which require solutions. Also, still other problems are presented purely from the standpoint of plastic molding procedure~ which are not present in the entirely different metal forming procedures.
lO. Comparing the structure of the metal container of the type herein involved and the resultant molded plastic container if such conversion is made, the metal container has the bottom wall thereof multiple-fold ~eam connected to the lower end of the 15. container sidewall and the engagement ring ~imilarly seam connected to the upper end of the container sidewall. Obviously, the common multiple-fold seam used with metal containers cannot be used in a plastic container. Although with a plastic container the 20. connection of the bottom wall with the container sidewall is not a problem since it can merely be integrally molde~ therewith, it does become a problem as to just how to provide a connection between the upper end of the container sidewall 25. and the engagement ring, particularly keeping in mind that it must be a pressure sealed connection.
Furthermore, with the metal container, the engagement ring and cover are merely formed with mating V-shaped annular recesses or grooves and the cover is 5. friction retained with the engagement ring merely by a friction fit between the mating V-shaped portions. It is again apparent that with plastic, friction retention will not suffice. Physical interengagement between the plastic cover and engagement ring must be somehow 10. incorporated. In addition with the plastic, a second pressure sealing zone must be provided to complete the pressure sealing requirements.
Still further, one of the requirements of the metal container i8 that it have a vertically straight 15. sidewall for the various reasons enumerated and this requirement presents a major difficulty in normal plastic molding processes. Most prior molded plastic containers, regardless of the other particular structure thereof, have had tapered sidewalls. The principal 20. reason that the sidewall~ are tapered i8 so that the container after molding can be easily re~oved from the mold. Here, however, we must have a straight sidewall between the sidewall end portion connections to the container bottom wall and to the upper engagement ring 25. assembled therewith.

I 16fi~0 Furthermore, the end portion connections of -the container sidewall to the container bottom wall and to the as~embled engagement ring must protrude transversely equal distances so that the a~sembled S. container, whether assembled merely with the engage-ment ring or with both the engagement ring and cover, will roll in a straight line for the reasons herein-before discussed. Thi~, therefore, again also involves the pressure sealing connection between the upper end 10. portion of the container sidewall and the engagement ring assembled therewith so that the transverse protru-sion of the assembly properly satisfies the equal distance requirement.

Objects and Summary of the Invention:
15. It is, therefore, an object of this invention to provide a container, engagement ring and coYer assembly which is uniquely constructed so as to be readily adaptable for the formation of the same totally from molded plastic, if desired, while still incorpoxa-20. ting therein one or more of various unique concepts partially or completely satisfying the manufacturing .
and marketing requirements of the similar, prior, totally metal assemblies.such as paint cans and the like. In a preferred embodiment thereof, the container 25. bottom wall is molded integral with the container ~ 16~s90 sidewall, the engagement ring i8 transverse flange interengaged with the container sidewall upper end, cmd the cover is transverse flange interengaged with the engagement ring, thereby eliminating necessity 5. of folded seam connections and metal-to-metal friction connections as required by the similar purely metal containers. In the same preferred embodiments, by prop.er preplanned dimensioning and known molding procedures, a chine or flange at the container sidewall 10. bottom end and the engagement ring assembled with the container sidewall at the container ~idewall upper end project equal distance~ transversely at ends of a straight sidewall 80 that the container assembly when positioned on its side will be supported and roll in a 15. straight line, one of the important requirements of the similar metal container assemblies required for being properly conveyed in the manufacturing process.
It is a further object of this invention to provide a container, engagement ring and cover assembly 20. of the foregoing general character and capable of providing the foregoing advantages wherein, in one form thereof, a unique combination of pressure sealing zones may be incorporated therein, when required, for pressure sealing the contents of a fully assembled 25. and filled container in an equally or superior manner _g_ ~ 3 fi6 ~ 9 ~) than with the prior metal container assemblies. Where this advantageous multiple pressure sealing concep~ is desired, the engagement ring is particularly configured so that an inverted U-shaped portion thereof telescopes 5- the upper end of the container sidewall providing a wall of the engagement ring inwardly of and outwardly abutting the container sidewall. Furthermore, an outer edge portion of the oover is provided with a similar wall positioned inwardly of the engagement ring wall 10. and outwardly abutting the same. Thus,by properly cal-culated formation of the cover and engagement ring, outward transverse pressure is exerted by the cover through its wall into the engagement ring wall and by the engagement ring wall into the container sidewall so 15. as to form multiple, interacting sealing zones which pressure seal the engagement ring and cover with the container so as to pressure seal the contents of the container assembly within the container during trans-portation and storage.
20. It is still another object of this invention to provide a container, engagement ring and cover assembly wherein, in a preferred embodiment thereof, not only is the engagement ring transverse flange interengaged with the upper end of the container 25. sidewall and the cover tran~verse flange interengaged I J66:~9(~

with the engagement xing as hereinbefore discussed, but the interengagement between the cover and the engagement ring may be of an interfitting unique nature so as to provide positive secure retainment of the 5- cover with the engagement ring when de~ired, yet permit ready removal of the cover when access to the container contents i8 desired. As hereinbefore pointed out, it is preferred to interengage the engagement ring with the upper end of the container sidewall by use of mating 10. transverse flanges and these may be of relatively permanent interengaged nature, since once assembled they will remain assembled. However, the tran~verse flange interengagement between the engagement ring and cover which must permit selective removal of the cover is 15. formed by constructing the engagement ring with a U-shaped portion inwardly of the container sidewall, and the cover with an edge portion which overlies the engagement ring U-~haped portion and projects downwardly therein. Still in the preferred form, the downward 20. projection of the cover edge portion include~ a part of the downward projection outwardly pres~ure abutting the engagement ring U-shaped portion and a part of the downward projection inwardly pressure engaging the previously described tranQver3e interengaged flanges.
25. ~he overall result is that in fully assembled po~ition, ~ ~ 66~90 the cover is securely retained with the engagement ring and will withstand relatively strong impact while retaining such engagement, yet by use of a tool engaged beneath a transverse flange at the periphery of the 5. cover, the cover may be selectively removed from such engagement for complete removal of the cover from the engagement ring.
Other objects and advantages of the invention will be apparent from the following specification and 10. the accompanying drawings which are for the purpose of illustration only.

Brief Description of the Drawings:
FIG. 1 is a side elevational view of a first preferred embodiment of container, engagement ring and 15. cover assembly incorporating certain of the principles - of the present invention;
FIG. 2 is a top plan view of the container, engagement ring and cover assembly of FIG. l;
FIG. 3 is an enlarged, vertical sectional 20. view looking in the direction of the arrows 3-3 in FIG. 2 and showing a second container, engagement ring and cover assembly in fragmentary, phantom view stacked thereon;
FIG. 4 is an enlarged, fragmentary, vertical 25. sectional view taken from FIG. 3 as indicated in FIG.

~ ~ 6~ 90 3, but showing the second container, engagement ring and CIDver assembly stacked thereon in full, sectional lines:
FIG. 5 is an exploded view of the assemblies of FIG. 4;
5- FIG. 6 is a fragmentary, vertical ~ectional view similar to FIG. 4, but showing a second preferred embodiment of container, engagement ring and cover assem-bly incorporating certain of the principles of the present invention;
10. FIG. 7 is a reduced, fragmentary, horizontal sectional view looking in the direction of the arrows 7-7 in FIG. 6;
FIG. 8 i8 a fragmentary, vertical sectional view similar to FIG. 4, but showing a third preferred embodiment 15. of container, engagement ring and cover assembly incorpora-ting certain of the principles of the pxesent invention:
FIG. 9 is a fragmentary, vertical sectional view similar to FIG. 4, but showing a third preferred embodiment of container, engagement ring and cover assembly incorpora-20. ting certain of the principle~ of the present invention; and FIG. 10 is a fragmentary, vertical sectional view taken from FIG. 9 and showing the bottom corner section of the container of FIG. 9 alone.

Description of the Best Embodiments Contemplated:
25. Referring to FIGS. 1 through 5 of the drawings, a first preferred embodiment of container, engagement ring and cover assembly incorporating certain of the principles ~ 166~9~

of the present invention in~ludes three basic elements, a container generally indicated at 10, an engagement ring generally indicated at 12 and a cover generally indicated at 14. As will be hereinafter discussed more in detail, 5- the container 10, engagement ring 12 and cover 14, as is also true for similar element8 of other embodiments of the present invention to be hereinafter described, are all particularly adapted for being formed by inje~tion molding the same from plastic. Furthermore, the particular plastic 10. used for such injection molding may be any one of a series of plastics used for molding containers and the like and the molding procedures used for forming the same may be generally of usual type, all well known to tho~e skilled in the art.
lS. More specifically, the first embodiment container 10 includes a generally horizontally extending bottom wall 16 transversely outwardly integrally molded at the peri-phery thereof with an upwardly open, straight vertical sidewall 18. At the joinder thereof, a transversely out-20. wardly and downwardly extending chine or flange 20 is inte-gxally molded of somewhat usual form. Thus, the bottom flange 20 supports the container 10 on a normal supporting surface retaining the bottom wall 16 slightly spaced upwardly therefrom. Also, the bottom wall 16 may include an upwardly 25. projecting, center recess 22 merely for molding purposes, and an upwardly projecting, peripheral clearance rece~s 24 for purposes to be hereinafter pointed out.

I ~ ~6:~90 The container sidewall 18 terminate~ spaced clownwardly from its upper end 26 in a downwardly facing, partially transversely recessed, generally transversely outwardly extending retainment flange 28 5- at an outer side 30 thereof. In specific preferred form, the retainment flange 28 extends transversely at or closely to right angles to the container sidewall 18 and preferably totally around the container sidewall.
An inner side 32 of the container sidewall 18 is 10. preferably straight merely forming a continuation of the remainder of the container sidewall.
The engagement ring 12 includes an outer, inverted U-shaped portion 34 integrally joined with an inner U-shaped portion 36, the two portions being annu-15. lar portions and forming a common, generally vertical wall 38 therebetween, in essence, the common wall being an inner or interior leg or wall of the inverted U-shaped portion and an outer or exterior leg or wall of the U-shaped portion. An outer or exterior leg 40 of the 20. inverted u-shaped portion 34 spaced outwardly from the common wall 38 is formed with an inwardly projecting, generally transverse retainment flange 42 spaced upward-ly from the lower termination of the exterior leg. In the preferred form shown, a~ be~t ~een in FIGS. 4 and 5, 25. the retainment flange 42 of the inverted U-~haped portion I 1 66 1` 90 34 is angled a few degrees sli~htly ~ownwardly from straight transversely in its inward extension.
E'urthermore, within the confined contour of the inverted U-shaped portion 34 above the exterior leg 5. retainment flange 42, the inner surface of the inverted U-shaped portion extends upwardly and then inwardly to the common wall 38 and then downwardly along the common wall relatively closely matching the exterior surfaces of the container sidewall 18, 10. as shown, including a straight common wall surface against a straight sidewall surface.
Inwardly of the common wall 38, the engage-ment ring U-shaped portion 36 extends tran~versely inwardly in a bottom part 44 and ultimately into a 15. generally vertical interior wall or leg 46 spaced inwardly from the common wall 38 and completing the U-shaped opening of the U-shaped portion 36. The U-shaped portion interior leg 46 is preferably arcuate over its upper end 48 which is of increased transverse 20. thickness toward the common wall 38 curving downwardly and then radiused inwardly into a downwardly facing, generally transversely extending retainment flange 50.
The engagement ring 12 is completed by a preferably annular, upwardly projecting stacking flange 52 at the 25. outer upper edge thereof generally upwardly aligned with ~ lfi~t~O

the exterior leg 40 of the inverted U-shaped portion 34, and three or more circumferentially spaced, down-wardly projecting positioning lugs 54 extending down-wardly from the bottom part 44 of the U-shaped portion 5- 36, the purposes of which will be hereinafter discussed more in detail.
The cover 14 is circular in configuration and includes a preferably generally transversely extending center portion 56 peripherally outwardly integrally 10. joined with a particularly configured, annular edge portion 58 by a connecting part 60. The cover center portion 56 may include a downwardly extending center recess 62 similar to the center recess 22 of the container bottom wall 16 and for similar molding pur-15. poses. More important, the cover center portion 56 is spaced slightly below the upward exten~ion of the edge portion 58 throughout its extent.
The cover edge portion S8, as clearly shown in FIGS. 4 and 5, includes a generally vertical, 20. interior wall 64 which joins the transverse cover connecting part 60 intermediate the interior wall vertical height, preferably approximately vertically - midway. Spaced upwardly from the connecting part 60, the cover edge portion S8 extends transversely outwardly 25. and is formed with a downward extension 66 preferably ~ ~ 66 ~ 90 transversely separated into two parts, a generally vertical exterior wall 68 and a gene~ally transversely inwardly angled flange portion 70. The downward extension flange portion 70 due to its inwardly angled 5. projection forms a partially upwardly faci~g retainment flange 72 with the edge portion 58 curving arcuately upwardly therefrom and then inwardly to the interior wall 64 as shown. Finally, the cover edge portion 58 is completed by a transversely outwardly projecting, 10. tool engagement flange 74 peripherally around the edge portion at upper termination of the downward extension exterior wall 68, also as shown.
In assembly of the container 10 and engage-ment ring 12, from the position shown in FIG. S to the 15. position shown in FIG. 4, the inverted U-5haped portion 34 of the engagement ring i8 telescoped fully downward-ly over the container upper end 26 during which the exterior leg 40 of the ring inverted U-shaped portion flexes outwardly and then back inwardly to transverQely 20. interengage the retainment flange 42 on the exterior leg of the ring inverted U-shaped portion securely beneath the retainment flange 28 on the container upper end 26. As shown in assembled position in FIG. 4, the container upper end 26 substantially fills the inverted 25. U-shaped portion 34 of the engagement ring 12 at least . -18-I :~ 6fi`~t) above the in~erengaged flanges between the container upper end and the ring inverted U-shaped portion, and t:he interengagement between the retainment flanges is quite ~ecure due to the fact that the retainment flange 5- 28 on the container upper end 26 extends substantially straight transverse and the retainment flange 42 on the ring inverted U-shaped portion 34 ex~ends only very slightly angled from straight transverse. Equally important, with the full telescoping of the ring 10. inverted U-shaped portion 34 with the container upper end 26 and the described retainment flange interengage-ment, the ring common wall 38 between the ring inverted U-shaped and U-shaped portions 34 and 36 is positioned lying flatwise against and outwardly transversely 15. flatwise abutting the inner side 32 of the container upper end 26 from spaced well beneath the interengaged flanges upwardly to very near the upper extremity of the container sidewall 18.
With this assembly of the containex 10 and 20. engagement ring 12 completed, the assembly is ready for filling with its intended contents, and following such filling, it is ready for the final assembly of the cover 14 therewith. Furthermore, with the preferred embodiment of the container, engagement 25. ring and cover assembly according to the present I J 66 3 9~

invention, this final as~embly step will involve two unique inventive concepts. One is the particular form of interengagement between the cover edge portion 58 and the U-shaped portion 36 of the engagement ring 5- 12 to complete the enclosure of the container assembly contents, and the other is the novel pressure sealing of the container assembly contents within and merely from such assembly.
The cover 14 in this final assembly step i8 10. positioned aligned over and brought downwardly against the engagement ring 12, from the position shown in FIG. 5 to the position shown in FIG. 4. The cover edge portion 58 assumes an overlyinq relationship with the U-shaped portion 36 of the engagement ring 12, the 15. interior wall 64 of the cover edge portion outwardly at least partially transversely abutting the interior leg 46 of the ring U-shaped portion and the downward extension 66 of the cover edge portion moving fully downwardly into the ring U-shaped portion. As the 20. downward extension 66 of the cover edge portion 58 completes its downward movement relative to the ring U-shaped portion 36, the downward extension exterior wall 68 of the cover edge portion 58 comes into transverse outward flatwise abutment with the engage-25. ment ring common wall 38 over all but a small portion ~ ~ ~6 ~ 90 of the exposed vertical extent of such common wall, while at the same time, the downward extension flange portion 70 of the cover edge portion 58 partially transversely interengages inwardly beneath the 5. interior leg retainment flange 50 of the ring U-shaped portion 36 placing the retainment flange 72 tr~nsverse-ly interengaged beneath the retainment flange 50.
Important to both the interengagement between the engagement ring U-shaped portion 36 and the cover 10. edge portion 58 and the pressure sealing of the entire container assembly, the cover center portion 56 is dimensioned constructed and arranged ~uch that the cover connecting part 60 exerts direct transverse outward pressure in this final assembly against the 15. cover edge portion 58. This results in tran~verse sealing pressure from the cover center portion 56 into the interior wall 64 of the cover edge portion 58 and thereby into the interior leg 46 of the ring U-shaped portion 36. Not only i8 the pressure sealing of the 20. overall container assembly augmented, but transverse outward abutment pressure at this point also assists the secure interengagement between the cover edge portion and the ring U-shaped portion. The interen-gagement at this point is, therefore, a secure 25. interengagement capable of withstanding impact abuse ~ 1 6~i I 9 o :in the overall assembly while still permitting selective disengagement of the cover edge portion 58 from the engagement ring 12 due to the particular arcuate contouring and interfitting of the various 5. parts and surfaces inv~lved.
The exertion of the transverse outward pressure by the cover center portion 56 also results in such transverse pressure being transmitted through the cover edge portion 58 into the downward extension 10. exterior wall 68. This causes the cover downward extension exterior wall 68 to transverse outward pressure abut and pressure seal against the engage-ment ring common wall 38 and the engagement ring common wall to transverse outward pressure abut and 15. pressure seal against the inner side 36 of the container sidewall upper end 26. This pressure sealing between the container 10 and engagement ring 12 may be even further augmented, if desired, by forming the engagement ring in free standing condition 20. a slight pressure fit with the container sideWall 18 which will additionally more securely stabilize the previously described interengagement of the retainment flanges therebetween.
Thus, in the final assembly of the first 25. preferred embodiment of container 10, engagement ring I ~66~.90 12 and cover 14 according to the present invention, the engagement ring is assembled with and securely -t:ransversely interengaged with the container sidewall upper end 26, and the cover edge portion 58 i8 5- assembled with and securely, but selectively removably, transversely interengaged with the engagement ring, preferably the engagement ring U-shaped portion 36 spaced inwardly from the container sidewall 18. At the same time, all three of these assembled elements 10. are pre.ssure sealed one with another, the cover edge portion 58 through its exterior wall 68 is pressure sealed with the engagement ring common wall 38 and the engagement ring common wall is pressure sealed with the container sidewall inner side 32 to overall 15. pressure seal the contents of the container assem~ly therein. Still further, by including the pressure sealing concept in com~ination with the interengage-ment concept in the same assembly, one augments the other so that each assists the other. Such assistance 20. is even further amplified by the possible inclusion, if desired, of the interior wall 64 of the cover edge portion 58 transversely outwardly pressure sealing against the interior leg 46 of the cover U-shaped portion 36.

1 :1 66 :~ 90 As best seen in FIG. 4 in the final assembly of this first preferred embodiment of container 10, e!ngagement ring 12 and cover 14, the tool engagement flange 74 of the cover edge portion 58 remains ~paced 5. ~bove the upper extremities of the cover inverted U-shaped portion 34. Therefore, any time that it is desired to gain access to the content~ of the container assembly, the blade of a usual tool (not shown) can be positioned beneath the tool engagement flange 74-with 10. sufficient upward urging of the cover edge portion 58 resulting in disengagement of its transverse interengage-ment with the engagement ring 12. Furthermore, during this upward urging of the cover edge portion 58 by the tool, the tool outward of its engagement with the tool 15. engagement flange 74 will bear downwardly against the engagement ring 12 80 as to insure the maintaining of the engagement ring interengagement with the container upper end 26. This, of course, will result in the cover 14 moving free of the engagement ring 12 so that access 20. to the contents is obtained, reassembly being accom-plished as in the original assembly hereinbefore described.
In addition to the foregoing, the preferred embodiment of the container, engagement ring and cover 25. . assembly of the present invention is particularly ~ 1 fifi ~ ~0 adapted for meeting others of the factory and marketing reguirements in manufacturing and use of the assemblie~
as a complete replacement for the prior totally metal constructions such as paint cans and the like. One 5. such important requirement is that of having a vertical-ly straight sidewall 18 on the container 10. The container 10 may be molded with a straight sidewall 18 by use of a longitudinally split mold and known molding procedures. Alt~ough mold costs are increased over those 10. for molding the prior tapered sidewall plastic containers, such cost increases are not prohibitive and the increased benefits obtained by the present invention far outweigh the increased cost disadvantages.
Additionally, the transverse projections of 15. the container bottom flange 20 and the engagement rinq 12 assembled with the container sidewall 18 are con-structed substantially identical. Thus, with the contain-er sidewall 18 being straight vertical, the container bottom flange 20 and the engagement ring l~ will support 20. either the container and engagement ring partial assembly or the total a~sembly with the cover for rolling in a straight line when positioned on its side. As previously discussed, this is an important requirement for conveying the assemblies and using the same conveying equipment 25. as with the prior metal constructions.

~ ~ fi 6 1 3 ~) A further feature for molding is shown in FIGS. 1 and 2. Where bail attachments, such as the bail attachments 76 are required, the container 10 is molded with a short portion of the bottom flange 20 5. removed in vertical alignment with the bail attachments as indicated at 78. This permits mold inserts to be used in a known manner. For similar production pur-poses, the po~itioning lugs 54 on the U-shaped portion 36 of the engagement ring 12 are provided for position-10. ing the engagement rings both in storage before and during assembly procedure.
In order to be compatible with usual manufac-turing procedures, and after assembly during ~torage and shipment, the container assemblies must be capable 15. of stacking and this provision is clearly shown in phantom lines in FIG. 3 and in full lines in FIG. 4.
As previou61y described, the container bottom wall 16 is formed with the peripheral clearance recess 24, and the bottom flange 20 at the periphery of the bottom 20. wall 16 and the sidewall 18 projects downwardly and outwardly. Also, the engagement ring 12 i8 provided with the upwardly projecting stacking flange 52. Thus, one assembled container may be positioned over another and the container bottom flange 20 of the upper will 25. rest on the engagement ring stacking flange 52 of the II~fi~9() lower. At the same time, the peripheral clearance recess 24 of the upper container bottom wall 16 will provide clearance space for the upward projection of the cover edge portion of the lower assembly as shown, 5. thereby permitting such nested stacking as well as radially stabilizing such stacking.
A second preferred embodiment of container, engagement ring and cover assembly incorporating cer-tain of the principles of the present invention is 10. shown in FIGS. 6 and 7. Specifically, the container 10 remains the same, the engagement ring is slightly altered and is generally indicated at 80, and the cover 14 remains the same except for a slight reduction in the peripheral size or horizontal 15. extension thereof. The changes to provide the slightly altered engagement ring 80 involve changes in the inverted U-shaped and U-shaped portions 34 and 36 thereof and particularly the wall structure there-between, as well as the location of the stacking 20. flange thereof which is now the stacking flange 82.
As shown in FIGS. 6 and 7, the single, vertical, common wall between the inverted U-shaped and U-shaped portion~ 34 and 36 is replaced by an assembled common wall formed by two radially spaced, 25. but joined, vertical walls, the interior vertical wall 84 of the inverted U-shaped portion 34 and a second 1 1 ~6~9~

wall which becomes the exterior vertical wall 86 of the U-shaped portion 36 when the U-~haped portion is pro-vided. These two vertical walls 84 and 86 are joined spaced radially apart by an upper extremity horizontal 5. connecting flange 88 which extends in such horizontal connection around the entire circumference of the engagement ring 80. Additionally, and equally important, the interior and exterior vertical walls 84 and 86 are radially supported and radially joined at circumferen-10. tially spaced locations completely circumferentially around the engagement ring 80 by a multiplicity of radially extending supporting ribs 90, each of which fills the major portion of the void between the interior and exterior vertical walls terminating spaced slightly 15. above the lower extremities of such vertical walls as clearly shown.
In essence, therefore, the interior and exterior vertical wall~ 84 and 86 of the engagement ring 80 with their horizontal connecting flange 88 and their 20. multiplicity of supporting ribs 90 again form what may be considered en masse the same as the previous radial pressure tran~ferring common wall as in the first embodi-ment, the common wall here merely being a more complex or multiple layer common wall. The interior vertical wall 25. 84 of the engagement ring 80 lies vertically flatwise against the inner side 32 of the container upper end ~ 1 ~fi~90 26 in as~embly and the exterior wall 68 of the cover edge portion downward extension 66 lies vertically -ilatwise against the exterior vertical wall 86 of the engagement ring U-shaped portion 36. Radial pressure 5. is, therefore, again transferred radially outwardly from the cover edge portion downward extension 66 into the exterior vertical wall 86 of ths engagement ring U-shaped portion 36. through the horizontal connecting flange 88 and the supporting ribs 90 into 10. the interior vertical wall 84 of the engagement ring inverted U-shaped portion 34, and finally into the container upper end 26 so as to provide the same pressure sealing effect as in the first embodiment.
Otherwise, the assembly of the container 10, the 15. engagement ring 80 and the cover 14 is precisely the same and with the cover being permitted to be of ~lightly less peripheral size.
The stacking flange 82 of this second embodiment assembly is relocated slightly radially 20. inwardly as shown in FIG. 6. This permits the bottom flange 2~ of a container 10 stacked thereabove to telescope thereover thereby ~lightly nesting therewith and being retained against radial dislocation during such stacking. As shown, the peripheral clearance 25. recess 24 of the upper container bottom wall 16 ~ :1 6fi~90 provides sufficient clearance to receive the cover slightly raised edge portion 58 therein for additional -nesting. Also, if desired for additional vertical support between the stacked assemblies, the lower cover 5. edge portion 58 may upwardly vertically abut the upper container bottom wall 16 within the peripheral clearance recess 24.
In a third embodiment of container, engagement ring and cover assembly as shown in FIG. 8, the construc-10. tion is virtually the same as the second embodiment with the exception of the removal of the second embodiment supporting ribs 90 and the addition of vertically spaced, peripheral serrations 92 on the interior vertical wall 84 of the engagement ring inverted U-shaped portion 34. With 15. the removal of the supporting ribs 90, some flexing between the interior vertical wall 84 of the engagement ring inverted U-shaped portion 34 and the the second vertical wall, in this case, the exterior vertical wall 86 of the engagement ring U-shaped portion 36 may take 20. place in the final assembly of the container 10, engage-ment ring 80 and cover 14, this depending on the strength and stiffness of the horizontal connecting flange 88 between these interior and exterior vertical walls. However, any reduction in pressure transference 25. so as to slightly reduce the pressure sealing between 13~fi~90 the engagement ring 80 and the container upper end 26 can be counteracted by the peripheral serrations 92 on the engagement ring interior vertical wall 84 act-ing against the vertical surface of the container 5. upper end 26. The engagement ring 80 will slightly flex at the locations of these peripheral serrations 92 to create a more positive sealing under any lesser pressure conditions.
Although in this third embodiment assembly 10. of FIG. 8, required sealing conditions may be presented wherein serration~, such as the serrations 92, can be advantageously added, use of serrations between variou~
surfaces for increasing pressure sealing need not be confined to the location shown either in this third 15. embodiment or the other embodiments of the present invention. For instance, serrations could be added for increasing sealing in the first embodiment of FIG. 4 between the cover exterior wall 68 and the engagement ring common wall 38 or between the engagement ring 20. common wall 38 and the container upper end 26. They could also be added in the second embodiment of FIG. 6 at these same general locations and similarly in the third embodiment of FIG. 8. All of this, of course, will be dependent on the particular conditions presented 25. and what sealing assists might be required, if any.

~ 166~90 Finally, a still further modification of the c:ontainer~ engagement ring and cover assembly of the E~resent invention is shown as a fourth embodiment in FIGS. 9 and 10. This modification primarily involves a slight alteration in the bottom flange 20 of the container 10 which also requires a slight modification in the inverted U-shaped portion 34 of the engagement ring 12 of the first embodiment shown in FIGS. 1 through 5 or the engagement ring 80 of the second and third 10. embodiments shown in FIGS. 6 and 7 or FIG. 8, respectively.
As illustrated in FIGS. 9 and 10, this fourth embodiment `
modification is shown in the third embodiment container, engagement ring and cover assembly, but as stated, could equally well be used with either of the first or second 15. embodiments.
Referring particularly to FIGS. 9 and 10, the single bottom flange 20 of the container sidewall 18 as shown for the first three embodiments is replaced by a substantially straight radially outwardly extending 20. supporting flange 94 preferably radially aligned with the bottom wall 16 and a substantially straight vertically downwardly extending suppor~ing leg 96 displaced slightly inwardly from the vertical extension of the container sidewall 18. Either of the supporting flange 25. 94 or supporting leg 96 may extend continuously ~ :1 fi~ :~ 90 circumferentially or may be formed in circumferentially spaced segments with spaces therebetween as long as they are relati~ely continuous circumferentially around the container 10 to serve their supporting functions to 5. be hereinafter described more in detail. Furthermore, due to this modification in the container 10 at the bottom wall 16 and sidewall 18 joinder, the inverted U-shaped portion 34 of the engagement ring 80 is required to be modified by moving the ~tacking flange thereon 10. radially outwardly as a stacking flange 98 aligned with the periphery of the engagement ring and projecting vertically upwardly substantially equal to the downward projection of the container supporting leg 96.
In normal freestanding condition of the con-lS. tainer lO as shown in ~IG. 10, the container when in upright position as shown will be supported on a generally horizontal surface by the supporting leg 96.
Also, when the container 10 is positioned on its side while assembled with the engagement ring 80, the ~0. radial outward projection of the supporting flange 94 is constructed substantially equal to the similar pro~ection of the engagement ring 80 from the container. Thus, the container 10 will be properly supported in upright position, and equally important, will be properly

2~. supported on its side with ~he sidewall 18 thereof ~ 1 6619~

parallel to a supporting surface so as to roll in a straight line just as with the other embodiments.
In the stacked condition as shown in FIG. 9, the supporting leg 96 of the upper container 10 nests 5. radially within the stacking flange 98 of the engagement ring 80 on the lower container 10, the supporting flange 94 of the upper downwardly supported on the stac~ing flange 98 of the lower and the supporting leg 96 of the upper downwardly supported on 10. the engagement ring 80 of thè lower. The upwardly projecting edge portion S8 of the cover 14 iQ received partially upwardly within the peripheral clearance recess 24 of the container bottom wall 16 as before so as to permit this nested stacking. Thus, in the stacked 15. condition, one assembly is properly supported stacked over another with the stac~ing flange 98 of the lower assembly aiding in preventing radial displacement therebetween due to the partially nested positioning presented.
20. Overall with all of the embodiments of the present invention, therefore, novel container, engage-ment ring and cover assemblies have been provided which are all adaptable to being molded totally of plastic, yet each is a marked improvement over the prior totally 25. metal constructions which they may be u~ed as an I 1 fi6~9~

improved substitute therefor. Furthermore, the preferred embodiments thereof are each further adapted for making use of all of the prior production equipment used with the similar totally metal constructions.
5. Although particular embodiments of the new and novel container, engagement ring and cover assembly of the present invention have been illustrated and described herein, it is pointed out that it is not in-tended to limit the principles of the present invention 10. to the exact constructions shown and described herein.
Rather, it is intended that the principles of the present invention be broadly construed within the specific limitations set forth in the appended claim~ including the patent equivalents thereof.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an assembly of a container, engagement ring and cover, the improvements including: the engagement ring having a generally inverted U-shaped portion telescoped downwardly over an open upper end of the container, said ring inverted U-shaped portion having interior wall means generally vertically and transversely abutting an inner side of said container upper end; the cover terminating transversely outwardly at said engagement ring in an edge portion at said ring inverted U-shaped portion with said edge portion having an exterior wall generally vertically and transversely abutting an inner side of said ring inverted U-shaped portion interior wall means; said engagement ring and cover being constructed and arranged exerting transverse pressure outwardly to abuttingly pressure seal between said cover edge portion exterior wall and ring inverted U-shaped portion interior wall means and between said ring inverted U-shaped portion interior wall means and container upper end inner side; at least partially transversely extending interengagement means between said container upper end and ring and between said ring and cover edge portion for retaining said ring against generally vertical separation from said container and said cover against generally vertical separation from said ring.

2. In an assembly as defined in claim 1 in which said interior wall means of said engagement ring inverted U-shaped portion includes a single thickness wall generally vertically and transversely abutting said inner side of said container upper end and generally vertically and transversely abutted by said edge portion exterior wall of said cover.

3. In an assembly as defined in claim 1 in which said interior wall means of said engagement ring inverted U-shaped portion includes a first generally vertical wall generally vertically and transversely abutting said inner side of said container upper end and a second vertical wall spaced transversely inwardly from said first vertical wall, said second vertical wall being transversely connected to said first vertical wall by a generally transversely extending flange, said second vertical wall being generally vertically and transversely abutted by said edge portion exterior wall of said cover.

4. In an assembly as defined in claim 1 in which said interior wall means of said engagement ring inverted U-shaped portion includes a first generally vertical wall generally vertically and transversely abutting said inner side of said container upper end and a second generally vertical wall transversely spaced inwardly from said first vertical wall, said second vertical wall being connected to said first vertical wall by a transversely extending flange and a multiplicity of generally transversely extending and circumferentially spaced ribs, said second vertical wall being generally vertically and transversely abutted by said edge portion exterior wall of said cover.

5. In an assembly as defined in claim 1 in which said engagement ring has an inner portion extending transversely inwardly and transversely inwardly spaced from said inverted U-shaped portion interior wall means, said interengagement means between said ring and cover edge portion being formed between said ring inner portion and said cover edge portion spaced transversely from said ring inverted U-shaped portion interior wall means.

6. In an assembly as defined in claim 1 in which said engagement ring has an inner portion extending transversely inwardly from said inverted U-shaped portion interior wall means, said inner portion having a generally vertically extending interior wall spaced transversely inwardly from said inverted U-shaped portion interior wall means; and in which said cover edge portion has a generally vertically extending interior wall spaced transversely inwardly from said cover edge portion exterior wall and transversely outwardly abutting said ring inner portion interior wall, said cover having a transverse connecting part integrally joined to said edge portion interior wall intermediate vertical extension of said edge portion interior wall and intermediate vertical height of said ring inner portion interior wall.

7. In an assembly as defined in claim 1 in which said engagement ring has an inner portion extending transversely inwardly from said ring inverted U-shaped portion interior wall means; in which said cover edge portion overlies said engagement ring inner portion; and in which said interengagement means between said ring and cover edge portion includes a flange on said ring inner portion interengaged with a flange on said cover edge portion.

8. In an assembly as defined in claim 1 in which said engagement ring has a U-shaped portion extending transversely inwardly from said inverted U-shaped portion, said U-shaped portion having an exterior wall common to and forming at least a part of said interior wall means of said inverted U-shaped portion, said U-shaped portion having a generally vertical interior wall spaced transversely inwardly from said common wall with said cover edge portion exterior wall abutting said common wall; in which said cover edge portion overlies said ring U-shaped portion with said cover edge portion exterior wall projecting downwardly into said abutment with said ring common wall; and in which said interengagement means between said ring and cover edge portion is between said ring U-shaped portion interior wall and said cover edge portion.

9. In an assembly as defined in claim 8 in which said exterior wall of said engagement ring U-shaped portion forms substantially the entire of said interior wall means of said inverted u-shaped portion so as to constitute a single thickness common wall common to both said inverted U-shaped and U-shaped portions, said common wall generally vertically and transversely abutting said inner side of said container upper end and being generally vertically and transversely abutted by said edge portion exterior wall of said cover.

10. In an assembly as defined in claim 8 in which said interior wall means of said engagement ring inverted U-shaped portion includes a first generally vertical wall generally vertically and transversely abutting said inner side of said container upper end and said exterior wall of said U-shaped portion forming a second vertical wall spaced transversely inwardly from said first vertical wall, said second vertical wall being transversely connected to said first vertical wall by a generally transversely extending flange so that said first and second vertical walls are functionally a common wall, said second vertical wall being generally vertically and transversely abutted by said edge portion exterior wall of said cover.

11. In an assembly as defined in claim 8 in which said interior wall means of said engagement ring inverted U-shaped portion includes a first generally vertical wall generally vertically and transversely abutting said inner side of said container upper end and said exterior wall of said u-shaped portion forming a second generally vertical wall transversely spaced inwardly from said first vertical wall, said second vertical wall being connected to said first vertical wall by a transversely extending flange and a multiplicity of generally transversely extending and circumferentially spaced ribs so that said first and second vertical walls functionally form a common wall, said second vertical wall being generally vertically and transversely abutted by said edge portion exterior wall of said cover.

12. In an assembly as defined in claim 1 in which said engagement ring has a U-shaped portion extending transversely inwardly from said inverted U-shaped portion, said U-shaped portion having an exterior wall common to said interior wall means of said inverted U-shaped portion, said U-shaped portion having a generally vertical interior wall spaced transversely inwardly from said common wall and said cover edge portion exterior wall abutting said common wall; in which said cover edge portion overlies said ring U-shaped portion with said cover edge portion exterior wall projecting downwardly into said abutment with said ring common wall; and in which said interengagement means between said ring and cover edge portion includes a transversely outwardly projecting flange on said interior wall of said ring U-shaped portion interengaged with a downwardly and transversely inwardly projecting flange on said cover edge portion.

13. In an assembly as defined in claim 1 in which said engagement ring has a U-shaped portion extending transversely inwardly from said inverted V-shaped portion, said U-shaped portion having an exterior wall common to said interior wall means of said inverted U-shaped portion, said U-shaped portion having a generally vertical interior wall spaced transversely inwardly from said common wall with said cover edge portion exterior wall abutting said common wall; in which said cover edge portion overlies said ring U-shaped portion with said cover edge portion exterior wall projecting downwardly into said abutment with said ring common wall; in which said interengagement means between said ring and cover edge portion is between said ring U-shaped portion interior wall and said cover edge portion; and in which said cover edge portion includes an interior wall extending generally vertically downwardly inwardly adjacent and transversely outwardly abutting said interior wall of said ring U-shaped portion, said cover having a generally transversely extending connecting portion terminating transversely outwardly joining said cover edge portion interior wall spaced downwardly from upper termination of said interior wall of said cover U-shaped portion.

14. In an assembly as defined in claim 1 in which said engagement ring has a U-shaped portion extending transversely inwardly from said inverted U-shaped portion, said U-shaped portion having an exterior wall common to said interior wall means of said inverted U-shaped portion, said U-shaped portion having a generally vertical interior wall spaced transversely inwardly from said common wall with said cover edge portion exterior wall abutting said common wall; in which said cover edge portion overlies said ring U-shaped portion with said cover edge portion exterior wall projecting downwardly into said abutment with said ring common wall; in which said interengagement means between said ring and cover edge portion includes a transversely outwardly projecting flange on said interior wall of said ring U-shaped portion interengaged with a downwardly and transversely inwardly projecting flange on said cover edge portion inwardly of said cover edge portion exterior wall; and in which said cover edge portion includes an interior wall extending generally vertically downwardly inwardly adjacent and transversely outwardly abutting said interior wall of said ring U-shaped portion, said cover having a generally transversely extending connecting portion terminating transversely outwardly joining said cover edge portion interior wall spaced downwardly from upper termination of said interior wall of said cover U-shaped portion.

15. In an assembly as defined in claim 14 in which said interior wall of said cover edge portion extends downwardly along said interior wall of said ring U-shaped portion to spaced downwardly of said cover connecting portion.

16. In an assembly as defined in claim 14 in which said cover edge portion terminates transversely outwardly in transversely projecting flange means spaced above and partially overlying said engagement ring exposed for engagement by a tool for selective removal of said cover from interengagement with said ring.

17. In an assembly as defined in claim 1 in which said cover edge portion terminates transversely outwardly spaced above said inverted U-shaped portion of said engagement ring in outwardly projecting flange means exposed for selective engagement by a tool to move said cover edge portion upwardly relative to said engagement ring and from said interengagement means retainment with said ring.

18. In an assembly as defined in claim 1 in which said container, engagement ring and cover are formed of plastic.

19. In a method of assembling a container and cover, the steps of: telescoping an engagement ring downwardly over an upper edge portion of an upwardly open container sidewall; during said engagement ring telescoping, positioning a wall of said ring outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said engagement ring telescoping, interengaging said engagement ring with said container sidewall to resist generally vertical separation of said engagement ring from said container sidewall; inserting a cover downwardly with an edge portion thereof moved into contact with said engagement ring; during said cover insertion, positioning a wall of said cover edge portion outwardly generally vertically and transversely abutting an inner side of an engagement ring wall; during said cover insertion, interengaging said cover edge portion with said engagement ring to resist generally vertical separation of said cover edge portion from said engagement ring; during and after said engagement ring telescoping and said cover insertion and due to the inherent structures thereof, exerting continuous generally transverse outward sealing pressure by said cover edge portion wall against said abutted engagement ring wall and by said abutting engagement ring wall against said container sidewall.

20. In a method as defined in claim 19 in which said method includes the further steps of:
during said engagement ring telescoping, positioning said ring wall as a single thickness wall of said ring outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said cover insertion, positioning said wall of said cover edge portion outwardly generally vertically and transversely abutting an inner side of said single thickness wall of said engagement ring; during and after said engagement ring telescoping and said cover insertion and due to the inherent structures thereof, exerting continuous generally transverse outward sealing pressure by said cover edge portion wall against said engagement ring single thickness wall and by said engagement ring single thickness wall against said container sidewall.

21. In a method as defined in claim 19 in which said method includes the further steps of: during said engagement ring telescoping, positioning said ring wall as a first wall of said ring outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said cover insertion, positioning said wall of said cover edge portion out-wardly generally vertically and transversely abutting an inner side of an engagement ring second wall transversely spaced from said first wall and connected thereto by flange means; during and after said engagement ring telescoping and said cover insertion and due to the inherent structures thereof, exerting continuous generally transverse outwardly sealing pressure by said cover edge portion wall against said engagement ring second wall and by said engagement ring first wall against said container sidewall.

22, In a method as defined in claim 19 in which said method includes the further steps of: during said engagement ring telescoping, positioning said ring wall as a first wall of said ring outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said cover insertion, positioning said wall of said cover edge portion out-wardly generally vertically and transversely abutting an inner side of a second wall of said engagement ring spaced transversely from said first wall and transversely connected thereto by flange means and circumferentially spaced transverse rib means; during and after said engagement ring telescoping and said cover insertion and due to the inherent structures thereof, exerting continuous generally transverse outward sealing pressure by said cover edge portion wall against said engagement ring second wall and by said engagement ring first wall against said container sidewall.

23. In a method as defined in claim 19 in which said method includes the further step of: during and after said engagement ring telescoping and said cover insertion, positioning a cover central wall portion exerting a continuous generally transverse outward pressure against said cover edge portion to exert a generally transverse outward sealing pressure by said cover edge portion wall against said abutted engagement ring wall and by said abutting engagement ring wall against said container sidewall.

24. In a method as defined in claim 19 in which said step of telescoping an engagement ring includes telescoping an inverted U-shaped portion of said engagement ring downwardly over said upper edge portion of said upwardly open container sidewall and positioning a V-shaped portion extending generally transversely inwardly from said inverted U-shaped portion; in which said step of inserting a cover includes positioning said cover edge portion overlying said engagement ring u-shaped portion and inserting a part of said cover edge portion downwardly into said engagement ring U-shaped portion; and in which said method includes the further steps of: during said engagement ring inverted U-shaped portion telescoping, positioning a wall of said ring inverted U-shaped portion outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said cover edge portion part insertion, positioning a wall of said cover edge portion part outwardly generally vertically and transversely abutting an inner side of a wall of said engagement ring U-shaped portion; during and after said engagement ring inverted U-shaped portion telescoping and said cover edge portion part insertion and due to the inherent structures thereof, exerting continuous generally transverse outward sealing pressure by said cover edge portion part wall against said abutted engagement ring U-shaped portion wall and by said abutting engagement ring inverted U-shaped portion wall against said inner side of said container sidewall.

25. In a method as defined in claim 19 in which said step of telescoping an engagement ring includes telescoping an inverted U-shaped portion of said engagement ring downwardly over said upper edge portion of said upwardly open container sidewall and positioning a U-shaped portion extending generally transversely inwardly from said inverted U-shaped portion; in which said step of inserting a cover includes positioning said cover edge portion overlying said engagement ring U-shaped portion and inserting a part of said cover edge portion downwardly into said engagement ring U-shaped portion; and in which said method includes the further steps of: during said engagement ring inverted U-shaped portion telescoping, positioning a wall of said ring inverted U-shaped portion outwardly generally vertically and transversely abutting an inner side of said container sidewall; during said cover edge portion part insertion, positioning a wall of said cover edge portion part outwardly generally vertically and transversely abutting an inner side of a wall of said engagement ring U-shaped portion; during and after said engagement ring inverted U-shaped portion telescoping and said cover edge portion part insertion, positioning a cover central wall portion exerting a continuous generally transverse outward pressure against said cover edge portion part wall to exert a generally transverse outward sealing pressure by said cover edge portion part wall against said abutted engagement ring U-shaped portion wall and by said abutting engagement ring inverted U-shaped portion wall against said inner side of said container sidewall.

26. In a method as defined in claim 19 in which said step of telescoping an engagement ring includes telescoping an inverted U-shaped portion of said engagement ring downwardly over said upper edge portion of said upwardly open container sidewall and positioning a U-shaped portion extending generally transversely inwardly from said inverted U-shaped portion; in which said step of inserting a cover includes positioning said cover edge portion overlying said engagement ring U-shaped portion; and in which said step of during said cover insertion, transversely interengaging said flange of said cover edge portion beneath said flange of said engagement ring includes transversely interengaging said flange of said cover edge portion beneath said flange on an inner leg of said engagement ring U-shaped portion.

27. In a method as defined in claim 19 in which said method includes the further step of: during said cover insertion, positioning a cover release flange located at an outer termination of said cover edge portion spaced above said engagement ring accessible by a tool to selectively release said cover edge portion from said flange interengagement with said engagement ring.

28. In a method as defined in claim 19 in which said method includes the further step of: forming each of said container, engagement ring and cover of plastic.