Thread Forming Apparatus And Associated Method

This application is a non-provisional application of and claims priority to U.S. Patent Application Ser. No. 63/644,089, filed May 8, 2024, titled, “Thread Forming Apparatus And Associated Method.”

The disclosed concept relates generally to thread forming apparatus for forming thread members and, more particularly to thread forming apparatus for forming thread members in beverage cans. The disclosed concept further relates to methods of forming thread members in beverage cans.

Metallic beverage containers are sealed by closures disposed on/over openings in order to protect the contents contained therein from being exposed to air, moisture or other environmental elements and prolong the shelf-life of the contents. Most metallic beverage containers are not resealable meaning once they are opened, they cannot be closed or resealed. Metallic beverage containers usually include “pull tabs” structured to be grabbed by the consumers via a ring and pulled to remove the top of the beverage container or “stay on tabs” to break open a perforated opening of the beverage container. These types of closures are common in metallic beverage containers, but once opened cannot be closed or resealed. Such lack of resealability results in inconvenience to the consumers who must intake the contents quickly upon opening before the contents lose carbonation, spoil, or oxidize. Few metallic beverage containers contain threaded closures that can be reclosed or resealed. However, creating such threaded closures is challenging. One challenge is that it is difficult to create threads in a can body due to the thinness of aluminum used in the can body. Such threads risk compromising the strength of the can body. Further it is challenging to create threads in a can body in a manner that is cost effective and conducive to high speed manufacture. Current resealable metallic beverage containers have not sufficiently met these challenges.

Hence, there is room for improvement in thread forming devices for metallic beverage containers. There is also a need for thread forming devices with high throughput for resealable beverage containers.

These needs, and others, are met by embodiments of the disclosed concept. In a first example embodiment, a thread forming apparatus structured to form a plurality of threads around a circumference of a can body having a base and a sidewall extending from the base is provided. The thread forming apparatus comprises: an outer ring including a plurality of projections disposed around an inner periphery of the outer ring, the outer ring being structured to remain stationary; an inner ring including a plurality of recesses disposed around an outer periphery of the inner ring; and an actuator coupled to the outer ring and the inner ring, wherein when the sidewall of a can body is positioned between the inner ring and the outer ring the inner ring is structured to be moved radially toward the sidewall of the can body and rotated against the sidewall and the projections, the rotation against the can sidewall and the projections causing can material to flow into the recesses and form the plurality of threads around the inner circumference of the can body, and wherein the actuator is structured to hold the outer ring stationary and move radially and rotate the inner ring against the can sidewall.

When the sidewall of a can body is positioned between the inner ring and the outer ring, upon actuation the inner ring may be moved outward and start to be rotated against the inner periphery of the outer ring, the rotation causing the inner ring to press against the can sidewall and projection against the can sidewall and a projection, and wherein the pressing causes the can material to flow into a recess and form an internal thread on the can sidewall. Upon completion of the forming of the internal thread, the inner ring may roll away from the internal thread and continues to be rotated to form remaining internal threads one by one. Upon completion of forming the remaining internal threads, the can body may be released from the apparatus. The inner ring and the outer ring may be structured to keep the can body stationary until the release.

In another example embodiment, a thread forming apparatus structured to form a plurality of threads around a circumference of a can body having a base and a sidewall extending from the base is provided. The thread forming apparatus comprises: an outer ring including a plurality of recesses disposed around an inner periphery of the outer ring, the outer ring being structured to be moved radially toward the can body such that one end of each recess contacts the outer circumference of the can body; an inner ring including a plurality of projections disposed around an outer periphery of the inner ring, the inner ring being structured to be moved among the recesses in a pattern and press the projections into the can sidewall and respective recesses, pressing the projections into the respective recesses causing can material to flow into the respective recesses and form the threads around the outer circumference of the can body; and an actuator coupled to the outer ring and the inner ring and structured to move radially the outer ring and the inner ring to form the plurality of threads in the pattern.

The pattern may be of a star shape. The plurality of recesses may be disposed equidistant around the inner periphery of the outer ring. The plurality of projections may be disposed equidistant around the outer periphery of the inner ring.

These and other objects, features, and characteristics of the disclosed concept, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are provided for the purpose of illustration and description only and are not intended as a definition of the limits of the disclosed concept.

Directional phrases used herein, such as, for example, clockwise, counterclockwise, left, right, top, bottom, upwards, downwards and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.

As used herein, the singular form of “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

As used herein, “structured to [verb]” means that the identified element or assembly has a structure that is shaped, sized, disposed, coupled and/or configured to perform the identified verb. For example, a member that is “structured to move” is movably coupled to another element and includes elements that cause the member to move or the member is otherwise configured to move in response to other elements or assemblies. As such, as used herein, “structured to [verb]” recites structure and not function. Further, as used herein, “structured to [verb]” means that the identified element or assembly is intended to, and is designed to, perform the identified verb. Thus, an element that is merely capable of performing the identified verb but which is not intended to, and is not designed to, perform the identified verb is not “structured to [verb].”

As used herein, “associated” means that the elements are part of the same assembly and/or operate together or act upon/with each other in some manner. For example, an automobile has four tires and four hub caps. While all the elements are coupled as part of the automobile, it is understood that each hubcap is “associated” with a specific tire.

As used herein, the statement that two or more parts or components are “coupled” shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, “directly coupled” means that two elements are directly in contact with each other. As used herein, “fixedly coupled” or “fixed” means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other. As used herein, “adjustably fixed” means that two components are coupled so as to move as one while maintaining a constant general orientation or position relative to each other while being able to move in a limited range or about a single axis. For example, a doorknob is “adjustably fixed” to a door in that the doorknob is rotatable, but generally the doorknob remains in a single position relative to the door. Further, a cartridge (nib and ink reservoir) in a retractable pen is “adjustably fixed” relative to the housing in that the cartridge moves between a retracted and extended position, but generally maintains its orientation relative to the housing. Accordingly, when two elements are coupled, all portions of those elements are coupled. A description, however, of a specific portion of a first element being coupled to a second element, e.g., an axle first end being coupled to a first wheel, means that the specific portion of the first element is disposed closer to the second element than the other portions thereof. Further, an object resting on another object held in place only by gravity is not “coupled” to the lower object unless the upper object is otherwise maintained substantially in place. That is, for example, a book on a table is not coupled thereto, but a book glued to a table is coupled thereto.

As used herein, the statement that two or more parts or components “engage” one another means that the elements exert a force or bias against one another either directly or through one or more intermediate elements or components. Further, as used herein with regard to moving parts, a moving part may “engage” another element during the motion from one position to another and/or may “engage” another element once in the described position. Thus, it is understood that the statements, “when element A moves to element A first position, element A engages element B,” and “when element A is in element A first position, element A engages element B” are equivalent statements and mean that element A either engages element B while moving to element A first position and/or element A either engages element B while in element A first position.

As used herein, “correspond” indicates that two structural components are sized and shaped to be similar to each other and may be coupled with a minimum amount of friction. Thus, an opening which “corresponds” to a member is sized slightly larger than the member so that the member may pass through the opening with a minimum amount of friction. This definition is modified if the two components are to fit “snugly” together. In that situation, the difference between the size of the components is even smaller whereby the amount of friction increases. If the element defining the opening and/or the component inserted into the opening are made from a deformable or compressible material, the opening may even be slightly smaller than the component being inserted into the opening. With regard to surfaces, shapes, and lines, two, or more, “corresponding” surfaces, shapes, or lines have generally the same size, shape, and contours.

As used herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality). That is, for example, the phrase “a number of elements” means one element or a plurality of elements. It is specifically noted that the term “a ‘number’ of [X]” includes a single [X].

As used herein, “about” in a phrase such as “disposed about [an element, point or axis]” or “extend about [an element, point or axis]” or “[X] degrees about an [an element, point or axis],” means encircle, extend around, or measured around. When used in reference to a measurement or in a similar manner, “about” means “approximately,” i.e., in an approximate range relevant to the measurement as would be understood by one of ordinary skill in the art.

As used herein, an “elongated” element inherently includes a longitudinal axis and/or longitudinal line extending in the direction of the elongation.

As used herein, “generally” means “in a general manner” relevant to the term being modified as would be understood by one of ordinary skill in the art.

As used herein, “substantially” means “for the most part” relevant to the term being modified as would be understood by one of ordinary skill in the art.

As used herein, “at” means on and/or near relevant to the term being modified as would be understood by one of ordinary skill in the art.

As the need for resealable cans increases, metallic beverage containers (e.g., without limitation, cans) with threaded closures that can be used to reseal the containers have been developed. However, the thread forming devices for the containers with the external threads are expensive and not conducive to high-speed manufacture. Example embodiments of thread forming apparatus in accordance with the disclosed concept achieve radial and rotating motion of an inner die to place threads (e.g., recesses, projections, or other thread forms) at a plurality of points along the circumference of the sidewalls of can bodies at a very high speed, resulting in a high-throughput manufacturing of the threaded, reusable metallic beverage containers, the high-throughput being substantially higher than the throughput by the existing thread forming devices for metallic beverage containers. As such, the example thread forming apparatus resolve the manufacturing inefficiencies and high costs associated with the existing thread forming devices for metallic beverage containers. Further, by pressing intermittent threads in top portions of metallic beverage containers, the example thread forming apparatus in accordance with the disclosed concept provide the containers a similar appearance to the appearance of the existing resealable beverage containers that require threads at the top of the containers as well as threaded inserts.

illustrate an exemplary thread forming apparatusin accordance with a non-limiting, example embodiment of the disclosed concept. The example thread forming apparatusis structured to form a plurality of threadsaround a circumference of a can body. The can bodyhas a baseand a can sidewallextending from the basein parallel to a central axisof the can bodyand defining an interior(see) of the can bodythat is structured to store a content therein. The can sidewallhas a rimforming an opening to the interior. The example thread forming apparatus is structured to form the plurality of threadsaround the circumference of the sidewall, of the can body, typically near the rim.

The thread forming apparatusis structured to form threadsat multiple points around the circumference of the sidewallof the can bodyand includes an outer ring, an inner ringand one or more actuators. The outer ringhas a plurality of projectionsdisposed around, and projecting radially inward from, an inner peripherythereof. The inner ringhas a plurality of recessesdisposed around, and extending radially inward to, an outer peripherythereof. Whileshow that the outer ringand the inner ringinclude six equidistant projectionsand six equidistant recesses, respectively, so as to form six equidistant internal threadsaround the inner circumference of the can bodyas shown in, it is to be appreciated that this is for illustrative purposes only, and thus the rings,may have more or less projections and recesses to form more or less threadsas appropriate for particular applications without departing from the scope of the disclosed concept. The one or more actuatorsare coupled to the outer ringand the inner ringand are structured to hold the outer ringstationary and radially move and rotate the inner ringagainst the interior of the sidewallof the can body. In some example embodiments, the one or more actuatorsmay move the outer ringradially for aligning the thread forming apparatusand the can bodyfor forming threads around the circumference of the sidewallof the can body. Whileshows one actuator, this is for illustrative purposes only, and it will be understood that multiple actuatorsmay be employed without departing from the scope of the disclosed concept. For example, the outer ringand the inner ringmay be held stationary or moved radially by a common actuator or individual actuators may be associated with the outer ringand the inner ring. The one or more actuatorsmay be any suitable actuating mechanism (e.g., without limitation, cams and cam followers). The one or more actuatorsare omitted fromfor economy of disclosure, but it will be understood that one or more actuatorsmay be employed in any of the disclosed embodiments.

Formation of the internal threadswill now be described with reference to. Whiledepict chronological movements of the outer and inner rings,without the can bodybeing positioned between the outer and inner rings,, the movements are described as if the can bodyis positioned therebetween for clarity and completeness of disclosure. As shown in, initially, the outer ringand the inner ringare coaxial and radially separate from each other. The rimand adjoining sidewallof can bodymay then be moved to be inserted between the outer ringand the inner ring, e.g., via a pusher pad (not shown) such as commonly known in the art. Alternatively, the can bodymay rest on, e.g., without limitation, a pusher pad (not shown), and the outer ringand the inner ringmay be moved axially in parallel to the central axisof the can bodyso as to receive the can bodytherebetween. That is, the outer ringmay be moved axially to encompass the outer circumference of the sidewallof the can bodyand the inner ringmay be inserted within the interiorof the can body. Upon positioning the can bodybetween the outer ringand the inner ring(see), the thread forming apparatusis actuated.

Upon actuation, the inner ringis moved radially toward the can sidewalland starts to be rotated clockwise against the inner peripheryof the outer ring(and thus, the interior of the sidewallof the can body) and a projection(see) of the outer ring. The inner ringcontinues to be rotated such that the projectionand the recessare aligned as shown in. In such example embodiment, each projectionof the outer ringhas a male thread form geometry (e.g., a protrusion, a protuberance, a ledge or other thread form geometry), and each recessof the inner ringhas a female thread form geometry that is a negative of the male thread form geometry of the projection, however, it is to be appreciated that such geometries may be generally reversed to form external threads without varying from the scope of the disclosed concept. With the sidewalldisposed between the projectionand the recess, pressing against the sidewalland the projectioncauses the can material to flow into the recessand form an internal thread(see) in the sidewall. The internal threadprojects inward from the sidewalland has a shape corresponding to the projectionand the recess. Upon completion of forming the internal thread, the inner ringrolls away from the newly formed internal threadand continues to be rotated to form the next internal threadadjacent to the newly formed threadin the sidewallof the can body. The inner ringcontinues to be rotated and presses against the sidewalland the remaining projectionsuntil the last internal threadof the plurality of internal threadshas been formed. Both the outer ringand the can bodyremain stationary during the formation of the internal threads. Whileshow the inner ringbeing rotated clockwise, this is for illustrative purposes only, and thus the inner ringmay be rotated counterclockwise as appropriate without departing from the scope of the disclosed concept. Upon forming all of the internal threadsin the sidewallof the can body, the thread forming apparatusreleases the can body.

shows the thread forming apparatusreleasing the can bodyupon forming all of the internal threadsaround the inner circumference of the sidewallof the can body. To release the can body, the inner ringis moved radially away from the can body, allowing the newly formed internal threadsof the can bodyto be separated from the projectionsand the recesses. In the position shown in, upon such separation, the can bodycan be moved away from the thread forming apparatus, the thread forming apparatuscan be moved away from the can body, or both can be moved away from each other.

illustrate another example thread forming apparatusin accordance with another non-limiting, example embodiment of the disclosed concept. The example thread forming apparatusis similar to the thread forming apparatusofexcept that the outer ringhas a plurality of equidistant recesses-(of the same geometry) around the inner peripherythereof, the inner ringhas a plurality of equidistant projections-(of the same geometry) around the outer peripherythereof, the inner ringis moved to cross the interiorof a can bodydiagonally or substantially diagonally in a star pattern, and the outer and inner ringsandtogether form a plurality of equidistant external threads (not shown) around the outer circumference of the sidewallof a can body. Thus, overlapping description for similar components has been omitted herein for brevity. Each external thread projects outward from the sidewallof the can bodyand has a shape corresponding to one of the projections-and one of the recesses-.shows the outer ringand the inner ringin the initial position when the apparatusis not actuated to form the external threads on a can body.

Formation of the external threads in a sidewallof a can bodyis described with reference to.illustrates chronological movements of the inner ringgenerally in a star patternfor forming equidistant external threads around the outer circumference of the sidewallof a can body(not shown in) that would be present between the outer ringand inner ringsimilar to as shown in. Upon positioning the can sidewallbetween the outer and inner ringsand, the inner ringis moved radially toward the can sidewalland a first recess, pressing a first projectioninto the can sidewall. Simultaneously, the outer ringis moved radially toward the can sidewallsuch that one endof the first recesscontacts the outer circumference of the sidewallof the can body. The inner ringthen rolls against the can sidewalland the inner peripheryof the outer ring, pressing the first projectioninto the first recess. With the can sidewalldisposed between the first projectionand the first recess, pressing the first projectioninto the first recesscauses the can material to flow into the first recessand form a first external thread at pointof the can sidewall. Upon forming the first external thread, the inner ringrolls out of the first recess, allowing the first external thread to separate from the first recess. As such, a projection rolls through a recess similarly to a heel-to-toe rolling of a human foot.

Upon such separation, the inner ringis moved away from the first external thread at pointand the first recessand continues to be moved diagonally or substantially diagonally in the star patternin order to form remaining external threads around the outer circumference of the can body. That is, the inner ringis moved diagonally away from the first external thread at pointto form a second external thread at an opposite pointon the sidewallof the can bodyusing second projectionand second recess. Upon forming the second external thread, the inner ringis moved substantially diagonally away from the second external thread at pointand the second recessto form a third external thread at a substantially opposite pointon the sidewallof the can bodyusing third projectionand third recess. Upon forming the third external thread, the inner ringis moved diagonally away from the third external thread at pointand the third recessto form a fourth external thread at an opposite pointon the sidewallof the can bodyusing fourth projectionand fourth recess. Upon forming the fourth external thread, the inner ringis moved substantially diagonally away from the fourth external thread at pointand the fourth recessto form a fifth external thread at a substantially opposite pointon the sidewallof the can bodyusing fifth projectionand fifth recess. Upon forming the fifth external thread, the inner ringis moved diagonally away from the fifth external thread at pointand the recessto form the last external thread at an opposite pointon the sidewallof the can bodyusing last projectionand last recess. Upon forming the last external thread, the inner ringis radially moved away from the last external thread toward the central axisand releases the can bodyfrom the thread forming apparatus.

In some example embodiments, the outer ring may include a plurality of equidistant projections and the inner ring may include a plurality of equidistant recesses. In those example embodiments, the inner ring is still moved substantially diagonally within the interiorof the can bodyin the star pattern, and the outer and inner rings together form a plurality of equidistant internal threads extending inward from the sidewallof the can body.

While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” or “including” does not exclude the presence of elements or steps other than those listed in a claim. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.