CA2022342A1

CA2022342A1 - Piercing closure

Info

Publication number: CA2022342A1
Application number: CA 2022342
Authority: CA
Inventors: Thomas Walter Osip; Jerold Wayne Montgomery; Paul Anthony Pezzoli
Original assignee: Abbott Laboratories
Current assignee: Abbott Laboratories
Priority date: 1989-08-03
Filing date: 1990-07-31
Publication date: 1991-02-04

Abstract

Abstract of the Disclosure This invention is concerned with a closure which permits the sterile opening of a membrane sealed container in a single-action motion which also maintains a hermetic seal under retort conditions. This closure includes a generally cylindrical side wall having threads along the inner surface thereof, a top with an upper surface having a protective rim extending upwardly therefrom, with the top also having a dome assembly with the protective rim extending above such dome assembly. The dome has a top and bottom surface, with at least one plow member projecting downwardly from the bottom surface of the dome.

Description

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PIERCING CLOSURE

Technica1 Field The present invention relates generally to a closure for a container, and more partieularl~, ~o a plastic closure which permits the sterile opening of a hermetic membrane seal in a single action motion.

Backaround Ar-To ensure proper nutritional support for newborn infants, many doctors and hospitals recommend the use of liquid pediatric nutritional products.
Pediatric nutritional products are utilized when breast feeding is not possible for either medical and/or social reasons. Furthermore, even in cases where breast feeding is possible, some mothers prefer the convenience afforded by the use of pediatric nutritional products.
in response to the need for pediatric nutritional products soy and milk-based liquid foods have been developed ror bottle feeding in conjunction with a rubber or latex nipple. Since the containers for these products should provide a t~elve to eighteen month shelf life, a hermetic seal must be provided across the top of the container. A hermetic seal is one which when in place is impervious to microbiological intrusion and external in-fluence.

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~resently the industry provides a hermetic seal through the use or a glass container, to which is secured by vacuum closure a stamped steel cap having a pre cut rubber, or vinyl plasticol gasket. This vacuum closure of the container is then subjected to temperatures above the ambient air temperature, and more specifically to retort conditions, whereby the hermetic seal must survive sterilization of the nutritional product and the container. Since the glass container and the stamped steel cap expand a similar amount and since a vacuum is present within the container, the hermetic seal is maintained during the sterilization process.
Due to concerns about material cost, container weight, and breakage, suppliers of nutri~ional products have sought to manufacture the nutritlonal product container from a plastic substance, such as polypropylene, which is relatively clear, optically and cost effective as compared to glass. The problem arises in attempting .o provide a cap for a plas'ic con~ainer which maintains a hermetic seal.
Since it is difficult to maintain a vacuum in a plastic container and conventional metal caps and plastics expand by a dissimilar amount, conventional metal caps c~n not mainiain a hermetic seal for plastic containers when subjec.ed .o retort condit10ns. Furthermore, the application of heat under re~ort conditions causes polymer relaxation or shrinkage, especially in the upper neck portion of the container. Injection or extrusion molded bottles are formed by s-tretching the polymer molecules while the heat of sterili~ation causes those molecules to relax and actually shrinks the diameter of the neck. This shrinkaye causes problems in main~alning a conventional metal cap on a plastic bottle. This shr1nkage also prevents the use of a conventional plastic cap on a plastic bottle~

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One solution to these problems would be to zpply a substantial amount of torque when initially capping the bo~tle, however the amount of torque necessary to maintain a conventional cap in place is so high that a perscn would not be able to easily twist off the cap following retort. Another possible solution would be to fabricate a bottle from a plastic which does not shrink at retort -temperatures and can maintain an internal vacuum without distortion. However, the cosl of providing such a bottle is prohibitive.
Another possible approach to the providing of a hermetic seal to a plastic container would be to utilize a barrier membrane, such as aluminum foil, such that -the integrity of the seal is independent of the closure. This primary mernbrane seal would be protected rrom accidental or premature puncture by an overcap of a conventional design. One type of foil seal is the type which is peelable.
However, in dealing with nut,itional products subjec. to spoilage;
peelable seals are not optimal for maintaining confidence that the product has not been tampered with, or for ensuring against spoilage.
A heat fused foil seal, which imparts a permanent se 1, is desirable:
However, the use of a heat-fused foil membrane necessitates that the outer cap be removed, followed by the piercing of the membrane seal with of a microbial laden device, such as scissors or a fingernail, thereby contaminating the product with bacteria.
It is thus apparent that a need eYists for an improved closure for a pre filled, membrane sealed nutritional product container which provides system seal integri-ty, as well as permitting the opening of the nutri~ional products container in a single action motion.

~2~3~2 Disclosure of the Invention There is disclosed a closure for a membrane sealed product container, said closure comprising, a generally cylindrical side wall, said side wall having threads along the inner surface thereof for threadedly engaging the nec~ of said container, a top, said top having an upper surface, said upper surface having a protective rim e~tend;ng upwardly therefrom, said top also haviny a dome assemb1~, said protective rim extending above said dome assembly, said dome assembly including a dome~ said dome having top and bottom surfaces, said bottom sur-face having at least one downwardly projecting plow member.
There is also disclosed a closure for a membrane sealed container~ said closure comprising, a generally cylindrical side wall, and a top, said top having a deformable dome assembly, said dome assembl~ having top and bottom surfaces, said bottom surface hav-ing at least one downwardly projecting plow memberl said plo~ member being oriented in said closure such that upon downward deformation or said dome, said plow member ruptures said membrane seal.
There is also disclosed a closure ror a membrane sealed product container, said closure comprising, a generally cylindrical side wall, said side wall having threads along the inner surface thereof for -threadedly "
engaging the nec.~ of said container, and a top having an upper surface, the improvement characterized in that said upper surface has a protective rim extending upwardly -therefrom, said top also having a dome assembly located centrally of said protective rim, said protect1ve rim extending above said ~122~2 dome assembly, said dome assembly including a dome and first and second wall sections, said first and second wall sections located bet~een s~id dome and said cylindrical side wall, said first wall sec-tion being thic~er than said second wall section, said dome having top and bottom surfaces, said bottom surface having a downwardly projecting plow assembly having cooperating plow members, each plow member ha~ing a proximal end portion and a distal end portion, said pro~imal end portion extending downwardly a greater distance from said bottom surTace than said distal end portion, said proximal end portion having a lower most portion thereo~ which acts as a piercing tip, said dome having a center rib extending across said dome, said center rib passing between said cooperating plow members, said dome having side ribs loca-ted between said plow members and said first w211 section, said si~e ribs being perpendicular to said center rib, said dome deformable upon the application or sufficient ,orce such that said piercing tip extends downwardly through the membrane seal of said container to 'orm a vented, pourable hole opening, whereas prior to deformation said piercing tip is located above said membrane seal.
The prDs2nt invention provides a closure which permits the opening OT a memorane-sealed pediat.ic nutri-tional product, adult nutritional product or pharmaceutical produc. container in a single-action motion without contaminating the nutritional or pharmaceutical product. Yet another important aspect o~ this invention is to provide a pediatric nutri-tional product container closure which cooperates with a container to ensure a hermetic seal. Still ye-t another important aspect o~ the present invention is to provide a removable cap which can be utilized with a plastic container, 2~223~2 ~herein the closure and container are able to survive retort conditions. Other aspects and advantages of the invention will be apparent from the following description, the accom~anying ara~ings and the appended claims.

Brief Oesc i~tion of the Drawinas Fig. 1 is a perspective view of a prior art glass bottle and a prior art stamped steel metal cap of the type used for pediatric nutritional products.
Fig. 2 is a perspective view of the closure in accordance with the present invention shown secured to a plastic container.
Fig. 3 is a side elevationa1 view o-f the closure shown in Fig. 2.
Fig. 4 is a top plan view of the closure.
Fig. S is a bot~om plan view of the closure.
Fig. 5 is a vertical sectional view taken along line 6-6 of Fig. 4.
Fig. 7 is a vDrtical sectional view taken along line 7-7 of Fig. 5.
Fig. 8 is a vertical sectional view taken along line 8-8 of Fig. 4.
-ig. 9 is a Derspective view on a greatly enlarged scale showing the closure as i. aDpears prior to deformation of the dome and showing the memDrane seal of the container as it appears after derormation of the dome hzs occur ed.
,-is. 10 is a bottom plan view of the closure after deformation has occurred.
Fig. 11 is a vertical sectional view similar to Fig. 6 but taken along line 10 10 of Fig. 9.
Fig. lZ is a vertical sectional view similar to Fig. 7 bu-t taken along line 11 11 of Fig. 9.

, -7-~2~2 Fig. 13 is a perspec.ive view similar to Fig. 2 but of a modified embodiment of the closure.
Fig. 14 is a vertical sectional vie~ taken along line 14-14 of Fig. 13.
Detailed Description of the InYention ~aving reference to the dra~ings, attention is directed first .o Fig. 1 which illustrates a prior art closure for a pediatric nutritional product container shown in conjunction with such a container, with the prior art closure being designated by the nu~eral 20 and the prior art pediatric nutritional container being designated by the numeral 22. The containers of the prior art are fabricated rrom glass while the prior art closures 20 are fabricated o; metal. The closures of the prior art comprise a Tlat top 24, stamped-st~el side walls 25 and a rubber gasket (not shown) positioned between the lip OT ~he nec.k of the con-tainer and the underside of the flat top 24.
Fig. 2 illustrates a closure for a product container embodying this invention designated generally by the numeral 30, shown in conjunction with a plastic container 32. The container 32 also has secured to its upper portion a tamper evident devic2 33 which has its opposire ends attached to the closur~
30 and container 32.
As can be seen in Figs. 2 through 5~ the closure 30 includes as a basic co~ponent thereor, cylindrical side wall 34 having an outer surfac2 35, as well as an inner surrace 36. Outer surface 35 is shown as having three dis-tinct portions, lower smooth portion 37 which serves as the base of the closure, knurled portion 38, and inclined portion 39. Along the inner surTace 36 are threads 40 for threadedly engaging the closure 30 to th~ threaded nec~
portion 42 of the container 32. The inner surTace 36 also reatures an inner 2 ~ 2 ~ 3 L~ ~
nclined portion 43. inclined substantially parallel to inclined portion 39 and inclined so as to substantially overlap threads 40.
As can be better seen in Figs 2, 3 and 4, the closure also includes a top 45 having an upper surface 47. Parts of this upper surface 47 include a lip a8 and a protec'ive rim ~9 with its rim wall ~0 located centrally of said lip 48.
As can better be seen in Figs. 6, 7 and 3, the closure also includes a dome assembl~ 51 haviny a dome 52, 'irst wall section i3 and second wall section ~4. Firs~ "all section 53 is relatively thick with respect to second wall section 54. This can be abserved b~ comoaring the distance between the lower sur,ace of the second wall secLion ;~ ~nd the lower surface of the first wall sec-Lion 56 to the upper sur,aca of the secvnd ~all sec ion 57 and the upper surfzce of first wall secticn ~-3. The lower sur,ace of the first wall section 56 is located directly centrally or the rim bottom surface 59.
As can be seen in Figs. 7 througn 10, dome 52 is shown as having a dome top surTace 60 as well as a dome bottom surface 61. The arc associated with the dome varies based on the height of Lhe rim ~all ;0 and the width of the closure. Projecting downwardly from Lhe dome bottom surrace 61 is a plow assembly 63 shown in the 3rer^erred embodimen; as cooperating c.oss hatched plow members including rirst plow member 64 and second plow member 6~.
A slight indentation in the dome bottom surface 61 such indentation extending across the dome ;2 ser/es as cen-ter rib 67. Center rib 67 passes between the cooperating plow members. Side ribs 6a and 69 extend perpendicular to the center rib in the prererred embodiment and are located between each plow member 64 and 65 and the flrs-t wall sectlon 53.

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Each plow member 64 and 6~ has a blade 71 located at .he proximal end of the plow member with respect to the center rib 67. The plow members 64 and 6 also have distal ends 73 located close to first wall section 53. The proximal end portion 72 extends downwardly a greater distance from the dome bottom surface 61 than does the distal end portion 73. The lower most portion of the pro~imal end portion 72 acts as a piercing tip 7~.
Rim wall 50 extends abo~e dome assembly 51 so as to prevent the accidental deformation o-f the dome about ~he pivot point formed by second wall section 54. However, the thic'cness of the dome assembly is such that it may be deformed upon the application of sufficient force F as shown in Figs. ll and 12. ,ig. lO shows the device in the open or deformed configuration. Upon the application of sufficient Corce r, the center rib ~7 asiists in the deformation of the dome i2 such that the coopera.ing plow members engage and extend downwardly through or pierce the membrane seal 77. The pierced seal is shown in Fig. 9 as having formed a vented pourable hole therein.
When de~ressed, while the center rib assists in deforming the dome ~2 as shown in Fig. ll, the side ribs 68 and 69 assist in forming the buckled effec' on the dome as shown in Fig. lZ. Preferably, the inner wall of the container 32 is overlaid by the first wall section ~3 such that the second wall section forms a "living hinge" to assist in easier deformation OT the dome.
Figs. 13 and 14 disclose a mod1fied closure 80 with a modified rim 81 which permits an area or discontinuity 82 with respect to the modified lip 83. The modified emoodiment OT the invention is desirable in ~nstances where an indivldual may not wish to contact the dome 52 with his or her lon~
-fingernail For fear or damaging the nail, or where an individual may need to ~22~2 ,pply additional for~e against the dome which can best be exerted by placing the flat por.ion of the thumb completely across the dome assembly.
Since the closure 30 of this invention may be utilized with a heat fused membrane seal 77, ~hether the laminate is foil or plastic, the plastic cap may be screwed onto the container with as much, or possibly less, torque than currently is used with conventional metal caps, since the microbial hermetic seal is now provided by the membrane seal 77. The maintaining of the membrane seal 77 between the top of the nec~ of the container 32 and the first wall section 53 precludes any accidental tearing around the heat fused edge of the seal 77.

~est Mode In actual operation, the closure is deTormed and .hen unscrewed from the container 32. Whereas prior to derormation the piercing ~ip is located above the memorane seal 77, the de,ormation provides ror a generally hourglass or rectangularly snaped puncture in the membr~ne seal. The presence of the protective rim 4q prevents accidental opening of the container 32 during shipping by preventing deformation of the acme so as to permit the plows to contact the membrane seal 77, as well as by prevonting such contact against a partially deformed dome in the event OT hydraulic shoc.~ occurring during shipping, which shoc~ would force the membrane seal to rise ever so slightly.
As the seal is broken, the individual opening the container hears an audible sound due to the derormation of the plastic and the rush of a1r into the coniainer. Furthermore, the hole which is formed is larqe enough (approximately 15/. or the surface ~rea of the membrane seal) to permit the 2~2~3~2 ~Iquid contents of the container to be poured, as well as venting the container.
The closure of this invention may be fabricated from any suitable polymeric material and is preferably fabricated from polypropylene or a polypropylene copolymer. Additionally, the relative thic~nesses of the cylinder wall 34 and top 45 may be selected to ensure ease of deformation yet adequate audible confirmation of deformation since if the dome deforms too loudly, questions may be raised as to whether the vacuum seal had already been bro~en.
Thus, the potential for problems in preserving the hermetic seal and surviving retort conditions is precluded by the present invention. Further, the closure permit, the opening of the container in a single action motion, since once the dome is deformed, the cap may be unscrewed from the container without any subsequent opening procedures such as could involve the use of a finger or tool to open the membrane seal.

Industrial ADD1 icabili v Annually, approximately 200,000,000 units of pediatric nutritional proaucts are distributed in the U.S. alone, with many of these units currently utilizing glass containers and stamped steel metal caps. The industry has long sought ways to eliminate the glass containers and move to a less expensive cap as well. This invention solves this long felt need.
~ hile the form of apparatus herein described constitutes a preFerred embodiment of this invention, it is to be understood that the invention is not limlted to this precise form of apparatus, and -that changes may be made therein without departing from the scope o-f the invention which is defined in the appended claims.

Claims

?t is claimed is:

1. A closure for a membrane sealed container, said closure comprising, a generally cylindrical side wall, said side wall having threads along the inner surface thereof for threadedly engaging the neck of said container, and a top, said top having an upper surface, said upper surface having a protective rim extending upwardly therefrom, said top also having a dome assembly, said protective rim extending above said dome assembly, said dome assembly including a dome, said dome having top and bottom surfaces, said bottom surface having at least one downwardly projecting plow member.

2. The closure as claimed in claim 1 wherein said plow member has a proximal end portion and a distal end portion, said proximal end portion extending downwardly a greater distance from said bottom surface than said distal end portion.

3. The closure as claimed in claim 2 wherein said proximal end portion has lower most portion thereof which acts as a piercing tip.

4. The closure as claimed in claim 1 wherein said dome assembly has first and second wall sections located between said dome and said cylindrical side wall, said first and second wall sections being of different thicknesses.

5. The closure as claimed in claim 1 wherein said bottom surface having projecting therefrom a plow assembly, said plow assembly having cooperating plow members.

The closure as claimed in claim 5 wherein said dome has a center rib extending across said dome, said center rib passing between said cooperating plow members.

7. The closure as claimed in claim 6 wherein said dome assembly has first and second wall sections located between said dome and said cylindrical side wall.

8. A closure for a membrane sealed pediatric nutrition container, said closure comprising, a generally cylindrical side wall, and a top, said top having a deformable dome assembly, said dome assembly having top and bottom surfaces, said bottom surface having at least one downwardly projecting plow member, said plow member being oriented in said closure such that upon deformation of said dome said plow member ruptures said membrane seal and thus opens said container.

9. A closure for a membrane sealed pediatric nutritional product container, said closure comprising, a generally cylindrical side wall, said side wall having threads along the inner surface thereof for threadedly engaging the neck of said container, and a top having an upper surface, the improvement characterized in that said upper surface has a protective rim extending upwardly therefrom, said top also having a dome assembly located centrally of said protective rim, said protective rim extending above said dome assembly, said dome assembly including a dome and first and second wall sections, said first and second wall sections located between said dome and said cylindrical ??de wall, said first wall section being thicker than said second wall section, said dome having top and bottom surfaces, said bottom surface having a downwardly projecting plow assembly having cooperating plow members, each plow member having a proximal end portion and a distal end portion, said proximal end portion extending downwardly a greater distance from said bottom surface than said distal end portion, said proximal end portion having a lower most portion thereof which acts as a piercing tip, said dome having a center rib extending across said dome, said center rib passing between said cooperating plow members, said dome having side ribs located between said plow members and said first wall section, said ribs being perpendicular to said center rib, said dome deformable upon the application of sufficient force such that said piercing tip extends downwardly through the membrane seal of said container to form a vented, pourable hole therein, whereas prior to deformation said piercing tip is located above said membrane seal.