Resealable Can End with Stay on Tab

This Application is a continuation of co-pending U.S. application Ser. No. 17/774,581, which was filed on May 5, 2022, as a United States National Stage Application under 35 U.S.C. Section 371 of International Patent Application No. PCT/US2020/059361, which was filed on Nov. 6, 2020, and which claimed priority to and the benefit of U.S. Provisional Application No. 62/932,633, filed on Nov. 8, 2019, all of which are hereby incorporated by reference as if fully set forth herein.

N/A

The invention relates generally to stay-on tab ecology beverage containers and, more specifically, to resealable can ends for such beverage containers.

Beverage container designers have developed many proposals for producing reclosable two-piece aluminum beverage containers having stay-on tab (SOT) ecology can ends (lids) wherein a portion of the contents can be saved for a later time. In the case of beverage cans, most of these inventions have required using a variation on a combination of materials, for example a displaceable polymeric insert mounted within a pour opening which provides an initially pressure resistant seal. None of these inventions have been commercially accepted on a widespread basis.

Recently, reclosable three-piece aluminum beverage containers have become popular in the energy drink market. These containers are reclosable by utilizing a lug-type closure added to the otherwise two-piece construction of the beverage container. Similarly, the beer market utilizes a two-piece aluminum beverage container with a threaded closure.

None of the current options has the universal and lightweight appeal of the SOT can end.

The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior can ends of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

A first aspect of the present invention is directed to a reclosable beverage can end comprising:

The first aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The tab may be rotatably mounted to the center panel. The curl of the metallic material of the center panel may extend upwardly from the public side of the can end, and the tab comprises a curl extending downwardly towards the public side of the center panel and matingly engaged with the pour opening curl. The tab curl may be non-circumferential to allow rotation of the tab from a first position covering the pour opening to a second position wherein the pour opening is uncovered. An epoxy and/or a surface energy modifier may be located between the tab and the center panel to form a seal therebetween over the pour opening, preferably a hermetic seal. The seal may be broken by rotating the tab on the center panel. The epoxy may be a thermally cured epoxy. The epoxy may be cured by induction heating. The epoxy may be cured by UV light. The reclosable beverage can end may further comprise a thermoset polymer layer between the tab and the center panel forming a seal therebetween over the center panel. The tab may be staked to the public side of the center panel by a rivet. The rivet may be formed from the material of the center panel and integral therewith. The tab may be rotatable about the rivet. The tab may comprise a tail portion extending outwardly and upwardly from a surface of the tab and configured for engagement by a user's finger to rotate the tab. The tail may be located on a first end of the tab opposite a second end of the tab covering the pour opening. The tail may be located on an end of the tab wherein a portion of the tab covering the pour opening is also located on the end of the tab. The reclosable beverage can end may further comprise a second tail wherein the tail is located on a first end of the tab opposite a second end of the tab which covers the pour opening and wherein the second tail is located on the second end the tab. The tab may comprise a finger hole. The finger hole may be located on a first end of the tab opposite a second end of the tab covering the pour opening.

A second aspect of the invention is directed to a reclosable beverage can end comprising:

The second aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The seal may be broken by rotating the tab on the center panel. The layer of the sealing material may have an annular shape. The layer of the sealing material may have a disk shape. The sealing material may be an epoxy. The epoxy may be a thermally cured epoxy. The epoxy may be cured by induction heating. The epoxy may be cured by UV light. The reclosable beverage can end may further comprise a thermoset polymer layer between the tab and the center panel forming the seal therebetween. The tab may be staked to the public side of the center panel by a rivet. The rivet may be formed from the material of the center panel and integral therewith. The tab may comprise a tail portion extending outwardly and upwardly from a surface of the tab and configured for engagement by a user's finger to rotate the tab. The tail may be located on a first end of the tab opposite a second end of the tab covering the pour opening. The tail may be located on an end of the tab wherein a portion of the tab covering the pour opening is also located on the end of the tab. The reclosable beverage can end may further comprise a second tail wherein the tail is located on a first end of the tab opposite a second end of the tab covering the pour opening and wherein the second tail is located on the second end the tab. The tab may comprise a finger hole. The finger hole may be located on a first end of the tab opposite a second end of the tab covering the pour opening. The pour opening may be at least partially defined by a curl of the metallic material of the center panel. The curl of the metallic material of the center panel may extend upwardly from the public side of the can end, and the tab comprises a curl extending downwardly towards the public side of the center panel and matingly engaged with the pour opening curl. The sealing material may be located between the tab curl and the curl of the metallic material of the center panel. The tab curl may be non-circumferential to allow rotation of the tab from a first position covering the pour opening to a second position wherein the pour opening is uncovered.

A third aspect of the invention is directed to a reclosable beverage can end comprising:

The third aspect of the invention may include one or more of the following features, alone or in any reasonable combination. The tab may be rotational along the public side of the center panel to selectively reclose the pour opening. The seal may be broken by peelably removing the peelable closure member from the center panel. The reclosable beverage can end may further comprise a layer of a sealing material between the peelable closure member and the center panel. The layer of sealing material may have an annular shape. The sealing material may be an epoxy. The epoxy may be a thermally cured epoxy. The epoxy may be cured by induction heating. The reclosable beverage can end may further comprise a thermoset polymer layer between the peelable closure member and the center panel forming the seal therebetween. The tab may be staked to the public side of the center panel by a rivet. The rivet may be formed from the material of the center panel and integral therewith. The tab may comprise a tail portion extending radially outwardly from a surface of the tab and configured for engagement by a user's finger to rotate the tab. The tail may be located on a first end of the tab opposite a second end of the tab covering the pour opening. The tail may be located on an end of the tab wherein a portion of the tab covering the pour opening is also located on the end of the tab. The reclosable beverage can end may further comprise a second tail wherein the tail is located on a first end of the tab opposite a second end of the tab covering the pour opening and wherein the second tail is located on the second end the tab. The flexible laminate may be a metal foil.

The reclosable beverage can of any of the above embodiments may be entirely produced from aluminum

Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

Referring to, a reclosable beverage can endfor containers (not shown) has a center panelseparated from a seaming curlby a circumferential wallextending downwardly from the seaming curlto a strengthening segmentwhich is joined to the center panel. The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum or steel. Beverage can ends for such containers are also typically constructed from a cutedge of thin plate of aluminum or steel, formed into blank end, and manufactured into a finished end by a process often referred to as end conversion.

The can endcan be joined to a container body by the seaming curlwhich is joined to a mating curl of the container body. The seaming curlof the can endis integral with the center panelby the circumferential walland the strengthening segment, typically either a generally U-shaped countersink or a fold, which is joined to a peripheral edge of the center panel, defining an outer perimeter of the center panel, often through an additional strengthening feature such as a circumferential step or other circumferential wall. This type of means for joining the center panelto a container body is presently the typical means for joining used in the industry, and the curl structure described above is formed in the process of forming the blank end from a cutedge of metal plate, prior to the end conversion process. However, other means for joining the beverage can end to a container body may be employed with the present invention.

The circumferential seaming curldefines an outer perimeter of the beverage can end. It is generally centered about a longitudinal or vertical axis, typically located at a center of a rivet.

The center panelhas a pour openingformed by an aperture in the center panel. The pour opening is at least partially defined by a curlof the center panelmetallic material. The curlmay be circumferential about the aperture. The curlis formed by a bend of the metal causing a convex lipand a concave receiver. The term “curl” is intended to encompass any bend-like structure directing the metal of the center panel out of a plane of adjacent portions of the center panel and, preferably, capable of mating with a similarly shaped structure on the tabto retain the tab in position over the aperture. The center panel may be shaped, inscribed, or contain other indicia defining a direction for tab rotation (see).

The center panelhas a public sideand an opposing product side, and a tabis attached thereto, preferably attached to allow for rotation of the tabalong the surface of the center panel. The tabhas a generally elongated body along a diametric first axis extending through a first end of the tab, a central webbing and an opposing second endof the tab. The tabis staked to the center panelby a rivetgenerally through a rivet aperture through a central portion of the tab.

An unsealing of a sealed pour openingis operated by the tab. A user rotates the tababout the rivet. This breaks a seal between the taband the public sideof the center panel. To facilitate this rotation, the lift endof the tabmay be configured with a finger hole() and/or one or more tail portions() extending outwardly from a surface of the taband the upwardly relative to the public sideof the center paneland configured for engagement by a user's finger to rotate the tab.

Rotation of the tabcan be facilitated by altering the geometry or size of the rivetand/or altering the rivet hole in the tabto provide a loose stake to the tab to the can end. This may or may not require a change in final stake tooling in a conversion press or the like, where the tabis staked or attached to the can end.

The seal is formed between the public sideof the center panel and a lower surface of the tab. The tabincludes a curlextending downwardly towards the public sideof the center paneland matingly engages with the pour opening curl. As best shown in, the tab curlwraps along the convex lipof the pour opening curl, which convex lipis formed from the product sideof the can end. A terminal end of the tab curlis received within the concave receiverof the pour opening curlto retain the tabover the pour opening. The tab curlmay be circumferential or, as shown in, non-circumferential to allow rotation of the tabfrom a first position covering the pour openingto a second position wherein the pour openingis uncovered (see, e.g.). The tab curlmay also be formed such as to help prevent over-rotation of the tab from the second position back to the first position (closed).

The seal may be further formed by layers of a sealing materialand/or scaling materialsdesigned to modify the surface energy of the sealing surfaces (see). The sealing material(s),is/are located between the taband a surface of the center panelthe sealing materialdesigned to modify the surface energy of the sealing surfaces may be located along the convex lipof the pour opening curlsuch that it engages a bottom surface of the tab, generally including the tab curl. Thus, multiple layers of scaling material(s),may be located between a surface of the taband the center panelwherein a combination of the sealing material(s),, the center paneland the tabforms a seal of the pour opening. The sealing material(s)may have an annular shape as shown inor be a disk shape as shown in. However, it should be understood that the sealing material(s),can take any shape or form which achieves the function of providing the necessary sealing of the pour opening. The sealing material(s),can be on the tabor the can endor both. Placing the sealing materials,on both surfaces permits a better seal when heat sealing or ultrasonic welding techniques are employed. The scaling material(s),preferably form(s) a hermetic seal.

Suitable surface energy modification techniques or layers include plasma activation, a layer of a wet chemical treatment, including grafting, and a layer of thin-film coating.

Optionally, the sealing materialmay be an epoxy, such as a thermally cured epoxy. The epoxy can be cured, for example, by induction heating or UV light. Alternatively, the sealing materialcan be a thermoset polymer layer between the taband the center panelforming the seal therebetween.

Alternatively, the sealing materialcan a thermoplastic polymer resin of the polyester family, such as polyethylene terephthalate (PET) or a polyolefin, such as polypropylene.

The rivetis surrounded by a circular coined region of the center panel. The coined region is a compressed portion of the center panelhaving a localized reduced thickness relative to adjacent portions of the center panel. Rivetssuch as this are formed from the metallic material of the center panelby forming the metal upwardly parallel to the longitudinal axis. Thus, the rivetis integral with the center panel. Rivetsare well known in the art of can end manufacture and design.

In operation, in a pour opening closed or initially sealed position shown in, the second endof the tabis positioned over the pour opening. The tab curlis mated with the pour opening curlto grip the tabthereto. To open or unseal the pour opening, the tabis rotated about the rivetto place the tabin an open or unsealed condition as shown in. This breaks the seal if the can endhas not been previously opened. In this position, the can endand the pour openingis in the open condition, and any contents of the beverage container can be poured from the pour opening. To place the can endin the closed or sealed condition, the tabis rotated back to the first position such that the second endof the tabis again located over the pour opening.

Alternative embodiments are illustrated in. In these embodiments, a bottom surface of the tabmay be sealed over the pour openingdirectly. Alternatively, the tabsof these embodiments can be configured with a curl, and the pour opening can also feature a curl.

In summary, referring generally to the figures, the present invention is directed to reclosable and/or resealable beverage can endsfor pressurized and unpressurized containers. The can endsare reclosable, e.g. through rotatable stay-on-tabs. The tabis fixed to the center panelof the can endby an integral rivet. As-manufactured, the seal is made, for example, by heat setting thermoplastics. The seal may be modified to case opening through oxide layers, chemical additives, or other processes.

The structures described herein further lend themselves to resealing beverage containers. As used herein, “reclosable” is intended to encompass a mild seal that may or may not leak liquid when the beverage container is turned upside down or falls on the floor. The term “seal” generally refers to a liquid tight enclosure or seal that may or may not also be gas tight. The term “resealable” indicates a gas tight seal that will not open under normal circumstance. For example, a user can toss the resealed beverage container into a backpack, or the beverage container can roll around on the floor of a car and stay closed. The seal is gas tight so carbonation loss is minimal.

The seal is broken by rotating the stay-on-tab. The tabmay be formed with hooks, such as curls of metal that are rotated from under the similar hooks or curls on the center panel. The hooks case manufacturing and reclosability. Thus, the invention provides metal, resealable can ends which are sealed by thermosetting plastics.

Prior practice has produced can ends which are all metal but not resealable. Container lids commonly used in the food industry utilize a thermosetting polymer to seal two metal surfaces, but there are no provisions to reseal the package.

The can ends of the present invention are novel relative to previous such can ends in the field because they combine the sealing mechanisms of peel-off closures with the resealability of rotating tabs. The present invention builds on the conventional can ends beverage containers where the can ends are sealed to the can bodies by double seaming.

It is believed that the novel components of this invention are stay-on-tabs affixed to the center panels by integral rivets; tabs are formed such that they hooks in place under curls of the center panels to ease manufacturing and reclosability. One or more tails or finger holes are provided to case rotation. Thermoset polymer layers between the tabs and center panelscan be heated to create heat seals. The heat seals would be broken by rotating the tabsfrom the sealed positions.

Referring to, an additional structure may be provided on one or more of the pour opening curland the tab curlto achieve a better, tighter reclosing, prevent accidental over-rotation of the tabalong the center panelfrom the second position back to the first position over the pour opening, and/or more securely lock the tabover the pour opening. For example, the pour opening and tab curls,may include an angle to draw the pour opening curland tab curltogether and compress the layer(s) of scaling material(s),therebetween. One or more detentsmay be formed in the pour opening and/or tab curls,. As shown in, the detentscooperate to lock the tabto the center paneland about the pour opening. More specifically, as the tabis rotated along the public sideof the center panel, a detenton the tab curlreceives a corresponding convex portionon the pour opening curl. Further, detentson the pour opening curl, which are located on opposite sides of the convex portionreceive corresponding convex portionsformed from the tab curland located on opposite sides of the tab curldetent.

An alternative embodiment is illustrated in. Here, the pour openingis initially sealed by a separate removable pour opening closure member. This pour opening closure member, such as a flexible metal foil closure, has a sealing portionextending over the pour openingand peelably bonded by, for example, one or more layers of a sealing materiallocated between the closure memberand the center panel, for example any of the options discussed above forming a seal with a portion of the center panelsurrounding the pour opening. The closure memberfurther includes a lift endwhich may be grasped by a user to lift and remove the closure memberfrom the center panel.

The closure membermay be produced from a laminate, for example a sheet material comprising metal foil, such as aluminum foil, preferably a suitably lacquered aluminum foil sheet or an aluminum foil-polymer laminate sheet. Stated more broadly, materials that may be used for the closure memberinclude, without limitation, lacquer coated foil (where the lacquer is a suitable heat seal formulation); extrusion coated foil (where the polymer is applied by a standard or other extrusion coating process); the aforementioned foil-polymer laminate, wherein the foil is laminated to a polymer film using an adhesive tie layer; and foil-paper-lacquer combinations such as have been used for some low-cost packaging applications.

The closure member stock may be a suitable deformable material such as an aluminum foil (e.g. made of alloy AA3104 or of a conventional foil alloy such as AA3003, 8011, 8111, 1100, 1200) with a thickness of 0.002 ins. to 0.004 ins. (50.8 μm to 101.6 μm) which is either lacquered on one side with a suitable heat sealable lacquer, or laminated on one side with a suitable heat sealable polymer film (e.g., polyethylene, polypropylene, etc.), 0.001 ins. to 0.002 ins. (25.4 μm to 50.8 μm) thick. The public sideshould have a suitable protective lacquer coating. It may be desirable to print onto the foil using known printing methods. It may also be desirable to emboss the laminate to make the closure easier to grip.

The closure memberand heat seal must be designed to withstand the force provided by the pressurized contents of a container. Therefore, the closure membermust be bonded to withstand tear/shear force resistance that range from 25 lb/in (0.45 kg/mm) to 75 lb/in. (1.34 kg/mm), or any range or combination of ranges therein.

When applied to the can end, the portion of the closure memberthat extends across the pour openingmay be substantially planar. When the can endis mounted on a container that is filled with a carbonated beverage, the pressure given off by the carbonation causes closure memberto bulge upwardly.

This embodiment includes a rotational tabwhich can be used to reseal the pour openingwhen desired.

The embodiment ofallows the manufacturer to make a can endwith cither a pour opening curlor no pour opening curl at all. Subsequently, outside the conversion press, the closure membercan be oriented and attached to the public sideof the center paneland about the pour openingto form a peelable seal which can be removed entirely, if desired, to unseal the pour opening. The rotational tabcan then be provided to reseal the contents of the container within the container vessel.

The tabcan be rotated or positioned over the closure memberafter the closure memberis applied to the pour opening. This would help prevent tampering and be helpful in preventing transport damage. A container opening sequence for user would be as follows: 1) rotate tab to expose the closure member; 2) peel the closure memberfrom the can end; and 3) rotate the tabto reseal the pour openingas desired.

In another embodiment, the closure membercan be attached to the tabor can endcenter panelsuch that the closure membercannot be removed easily. This would prevent litter from the closure memberand prevent possible hazards.

As illustrated in, the closure membercan be applied to a pour opening curl. This arrangement can be used in combination with the previously described embodiments featuring one or more sealing materials,. To provide enhance a sufficient seal between the closure memberand the pour opening curl, a feature can be formed on the pour opening curl, such as a flattened portionof the pour opening curl. This flattened portionis generally circumferential, and its position on the pour opening curlcan further enhance the seal. For example, the flattened portioncan be positioned on a top of the pour opening curl, such that the flattened portionis within about ±5 degrees of horizontal (see), the flattened portioncan be positioned radially outwardly in relation to the pour openingsuch a linedrawn parallel to the flattened portionforms an obtuse angle θ with a central vertical axisof the pour openingwhen viewed from the public sideof the can end(see), or the flattened portioncan be positioned radially inwardly in relation to the pour openingsuch a linedrawn parallel to the flattened potionforms an acute angle γ with a central vertical axisof the pour openingwhen viewed from the public sideof the can end(see).

Referring to, the tabcan be retained to the center panelby a rivetthat is offset from the longitudinal axis. The arrow onshows the tab is rotatable about an axis passing through the rivet. This configuration allows for a wider pour opening. In this embodiment, the can endis opened by pulling the tabupwardly from the public sideof the can endto break a seal and by rotating the tababout the rivet.

As shown in,B andA,B, tab curlsmay or may not engage pour opening curlsto aid in retaining the tabin the pour opening reclosed position. The tabcan have a concave portionthat extends into the pour opening. In,B, the tabfeatures a plug portionthat can be positioned within the pour openingto thwart fluid leakage. When viewed from the public sideof the can end, the plug portionis a concave recess. In,B, the tabhas a substantially planar portionconfigured to be placed over the pour opening. The inventors contemplate that the tabsof this embodiment can be provided with any of the embodiments described above, including but not limited to the closure members, curl geometries, and sealing materials,set forth above. The sealing material,may be applied to a circumferential wall of the plugthat fits within the pour opening as illustrated and may have a frustoconical shape/orientation (see). Additionally, the center panelof this embodiment may include the retaineras described below and illustrated in.