Thread Forming Apparatus and Associated Method

This application is a non-provisional application of, and claims priority to, U.S. Provisional Patent Application Ser. No. 63/644,064, filed May 8, 2024, titled “Thread Forming Apparatus And Associated Method.”

The disclosed concept relates generally to thread forming apparatus and, more particularly, to thread forming apparatus for forming threads for resealable beverage cans. The disclosed concept further relates to methods of forming threads in can bodies for resealable 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. As a first aspect, a thread forming apparatus structured to form one or more threads on a can body having a base and a can sidewall extending from the base is provided. The thread forming apparatus comprises: a punch assembly comprising: a punch cam; and a punch comprising: a punch body having a first end and an opposite second end, the first end engaged with the punch cam; and a punch projection disposed at the second end of the punch body, the punch being structured to move radially in response to engagement with the punch cam; and a die assembly disposed adjacent to the punch assembly, the die assembly and the punch assembly defining a clearance therebetween structured to receive a portion of the sidewall of the can body, the die assembly comprising: a die cam structured to move axially parallel to the central axis; and a die including: a top portion having a die recess; and a bottom portion engaged with the die cam, the die being structured to move radially in response to axial movement of the die cam, wherein the punch projection is structured to deform the portion of the sidewall of the can body into the die recess in a manner which forms the thread.

The apparatus may further comprise a number of actuators coupled to the punch cam and the die cam. The number of actuators may be structured to axially move the punch cam and the die cam. The die may further comprise a die guide structured to provide a linear guide to the die. The punch may further comprise a punch guide engaged with the punch body and structured to constrain movement of the punch body to linear motion. The punch may comprise a punch cam follower disposed at the first end of the punch body and engaged with the punch cam. The punch cam may be structured to slide axially parallel to a central axis of the can body. In order to position the punch assembly and the die assembly for forming an internal thread on the can body, the punch cam may be axially moved such that the punch projection is adjacent the sidewall of the can and the die cam is axially moved such that the recess is adjacent sidewall of the can opposite the punch projection. In order to form an internal thread, the punch cam may be moved axially toward the base of the can body such that the punch projection is pressed radially toward the can sidewall and into the recess, thus forming the internal thread. In order to release the can body, both the punch cam and the die cam may be moved axially away from the base of the can body such that the punch projection and the recess move away from the can sidewall and the newly formed internal thread.

As another aspect, a method of forming one or more threads on a can body having a base and a sidewall extending from the base is provided. The method comprises: disposing a portion of the sidewall of the can body in a clearance between a punch projection and a die recess of a die; moving the punch projection and the die recess toward the portion of the sidewall of the can body so as to form a thread in the portion of the can body in the die recess about the punch projection; and moving the punch projection and the die recess away from the portion of the sidewall of the can body so as to release the thread from the die recess and the punch projection.

The method may further comprise removing the portion of the sidewall from the clearance. The method may further comprise: rotating the can body about a central longitudinal axis thereof so as to dispose a second portion of the sidewall of the can body in the clearance between the punch projection and the die recess of the die; moving the punch projection and the die recess toward the second portion of the sidewall of the can body so as to form a thread in the second portion of the can body in the die recess about the punch projection; and moving the punch projection and the die recess away from the second portion of the sidewall of the can body so as to release the thread from the die recess and the punch projection. The method may further comprise: disposing a second portion of the sidewall of the can body in a clearance between a second punch projection and a die recess of a second die; moving the second punch projection and the die recess of the second die toward the second portion of the sidewall of the can body so as to form a second thread in the second portion of the can body in the die recess of the second die about the second punch projection; and moving the second punch projection and the die recess of the second die away from the second portion of the sidewall of the can body so as to release the second thread from the die recess of the second die and the second punch projection.

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 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 a thread forming apparatus in accordance with the disclosed concept achieve radial motion of a punch and a die to place threads (e.g., recesses, indentations, or other thread forms) at a plurality of points along the circumference of cans (or other suitable container) at a very high speed, resulting in a high-throughput manufacturing of the threaded, reusable metallic beverage containers that is substantially higher than the throughput of existing thread forming devices for metallic beverage containers. As such, exemplary thread forming apparatus in accordance with the disclosed concept resolve the manufacturing inefficiencies and high costs associated with the existing thread forming devices for metallic beverage containers. Further, due to such capability to produce a high-throughput at a high-speed, the exemplary thread forming apparatus can be easily included in a can manufacturing assembly line, thereby providing a one-stop shop for manufacturing cans that satisfy customer needs and demands for resealable, reusable and environmentally friendly cans.

illustrates an exemplary thread forming systemhaving an example thread forming apparatusin accordance with a non-limiting, example embodiment of the disclosed concept. The example thread forming apparatusis shown throughout.illustrate another example thread forming apparatus′ having similar features as the example thread forming apparatusexcept a few differences discussed further in detail with reference tobelow. As shown in, an example thread forming systemin accordance with the disclosed concept includes an example thread forming apparatusfor forming threads on a can body. The can bodyhas a base, a sidewallextending axially from the base(about a central longitudinal axis) and defining an interior. The sidewallhas a rimopposite the basethat defines an opening (not numbered) in the can bodyto the interior.

The thread forming apparatusis structured to form threads at multiple points around a circumference of the sidewallof the can bodygenerally adjacent the rimand includes a punch assembly, a die assemblyand one or more cam actuators. The punch assemblyincludes: a punch cam, which in the example shown inis structured to slide axially parallel to the central longitudinal axisof the can body, and a punch. The punchincludes a punch bodyhaving a first endand an opposite second end. The punchfurther includes a punch cam followerdisposed at the first endof the punch bodyand a punch projectiondisposed at the second endof the punch body. The punch cam followeris engaged with the punch camand, in the example shown in, is structured to move the punch body, and thus the punch projection, radially (with respect to central longitudinal axis) in response to axial sliding of the punch cam; between an initial punch position (as shown in) to a thread forming punch position (as shown in) thereof. The punchfurther includes a punch guidethat is engaged with the punch bodyand structured to constrain movement of the punch bodyto linear motion perpendicular to the central longitudinal axis.

In some example embodiments, the punch camis a wedge cam and the punch cam followeris a roller. In such example embodiments, as the punch cammoves axially in parallel to the center longitudinal axisof the can body, the punch cam followerrolls along an angled cam faceof the punch cam. As the punch cammoves axially toward the baseof the can body, the angled cam faceof the punch camcauses the punch cam followerto move in a radial direction toward the can body. As the punch cammoves axially away from the baseof the can body, the angled cam faceof the punch camallows the punch cam followerto move in a radial direction away from the can body. A biasing member(e.g., a spring or other suitable member) may bias the punch body, and thus the punch projectionand the punch cam followerin a radial direction away from the can body. In some example embodiments, the linear guidemay be lubricated to assist with smooth movement of the punch body. In some example embodiments, the linear guidemay be a portion of a cam guide.

The die assemblyis disposed adjacent to, but spaced a predetermined distance from, the punch assemblyand thus defines a clearance() therebetween that is structured to receive a portion of the sidewallof the can bodysuch that the portion of the can bodyis disposed between the punch assemblyand the die assembly. The die assemblyincludes a die camcoupled to a die cam rolling contact(e.g., without limitation, a sphere) structured to move axially parallel to the central longitudinal axisof the can body. The die assemblyalso includes a diehaving a top portionhaving a die recess, a bottom portion, and a shaftconnecting the top portionand the bottom portion. The bottom portionincludes an angled face. The dieis structured to move radially in response to axial movement of the die cam. For example, axial movement of the die camtoward the baseof the can bodycauses the die cam rolling contactto press against the angled faceof the bottom portionof the dieand move the dieradially toward the punch assembly. Axial movement of the die camaway from the baseof the can bodyallows the dieto move radially away from the punch assembly. A die guidemay be disposed around the shaftof the dieto act as a linear guide for the radial movement of the die.

One or more actuatorsare coupled to the punch assemblyand the die assemblyand are structured to axially move the punch camand the die cam. Whileshows one actuator, this is for illustrative purposes only, and it will be understood that one or more actuators(of any suitable arrangement(s)) may be employed without departing from the scope of the disclosed concept. For example, the punch camand the die cammay be moved axially by a common actuatoror individual actuatorsmay be associated with the punch camand the die cam. The one or more actuatorsmay be any suitable actuating mechanism or arrangements (e.g., without limitation, a motor, a servo motor, a solenoid, etc.) that provide actuation generally independently and or via interaction with other elements (e.g., an arrangement using one or more followers that follow a moving and/or fixed cam profile). The one or more actuatorsare omitted fromfor economy of disclosure, but it is to be understood that one or more actuatorsmay be employed in any of the disclosed embodiments. In some example embodiments, the one or more actuatorsmay be actuated manually or automatically remotely via a user, workstation, or any other suitable arrangement communicatively coupled to the apparatus.

The punch projectionof the punchhas a male thread form geometry (e.g., a protrusion, a protuberance, a ledge or other thread form geometry), and the recessof the diehas a female thread form geometry that is a negative of the male thread form geometry of the punch projection. With the sidewallof the can bodydisposed in the clearancebetween the punch projectionand the recess, pressing the punch projectioninto the recesscauses the can material therebetween to flow into the recessand form an internal thread(see) in the sidewallof the can body. As its name suggests, the internal threadprojects inward from the sidewalland has a shape corresponding to the punch projectionand the recess.

Formation of the internal threadis generally shown in. In, the punch camis disposed such that the punch projectionis next to the sidewallof the can bodyand the die camis disposed such that the recessis next to the sidewallopposite the punch projection. In this positioning, the internal threadis ready to be formed. In some examples, the top portionof the dieincludes a sliding edgeso as to assist with positioning the sidewallof the can bodyin the clearancebetween the punch projectionand the recess.shows the internal threadbeing formed. To form the internal thread, the punch camis moved axially toward the baseof the can bodysuch that the punch projectionis pressed radially toward the sidewallof the can bodyand into the recessof the die, thus forming the internal thread.shows the thread forming apparatusreleasing the can body. To release the can body, both the punch camand the die camare moved axially away from the baseof the can bodysuch that the punch projectionand the recessmove away from the sidewalland the newly formed internal thread. In the position shown in, 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. Additionally, the can bodymay be rotated on its central axisif the same punch projectionand recesswill be used to form another internal threadalong the circumference of the sidewallof the can body.

As noted above, in some example embodiments, the same punch projectionand recessis used to form multiple internal threads. In some such embodiments, the thread forming apparatusmay include a single punch assemblyand a single die assembly. However, it will be appreciated that in some example embodiments, the thread forming apparatusmay include multiple punch assembliesand multiple die assembliesstructured to be disposed around the circumference of the sidewallof the can body. In such embodiments, a single thread forming operation may form multiple internal threadsaround the circumference of the sidewallof the can body.

In some example embodiments, the die guidefurther includes a legextending axially inwardly into the interiorof the can bodyand is structured to hold the top portionof the dieupon radially retracting the diefrom the sidewallof the can bodyas shown in.

In some example embodiments, the dieincludes a biasing member(e.g., a spring) structured to bias the dieradially toward the central axisof the can body. The biasing members(previously discussed) andcause the punchand dieto move away from each other and the sidewallof the can bodywhen not being pressed toward the sidewall. In some example embodiments, the one or both of the biasing membersandmay be omitted and additional cams may be employed to move the punchand dieaway from the sidewall. For example, a first cam may be employed to move the punchtoward the sidewalland a second cam may be employed to move the punchaway from the sidewall, and a similar arrangement may be employed with the diewithout departing from the scope of the disclosed concept.

In some example embodiments, the punch cam guidemay have a contour that corresponds to the exterior contour of the sidewallof the can body, as shown for example in. Similarly, the die guidemay have a contour that corresponds to an interior contour of the sidewallof the can body, as shown for example in.

It will be appreciated that in some example embodiments, the axially moving punch camand/or die cammay be replaced by radial cams that rotate rather than move linearly. In some example embodiments, one or more lobed shafts may be employed in place of the punch camand/or die cam. For example, in an embodiment with multiple die assemblies, a lobed shaft may be placed along the central axisof the can body. Rotation of the lobed shaft causes the lobe of the lobed shaft to sequentially actuate each dieindividually. A cylindrical structure with a lobe can similarly be employed to actuate the punches. Coordinated rotation or coupling of the lobed shaft and cylindrical structure would result in synchronized actuation of corresponding diesand punches.

illustrate an exemplary thread forming apparatus′ in accordance with a non-limiting, example embodiment of the disclosed concept. The thread forming apparatus′ is similar to the thread forming apparatusof, except that the top portion′ of the die′ does not include a sliding edgeof the thread forming apparatus, the recess′ of the die′ is wider than the projectionof the punchsuch that an internal thread formed therebetween may not have the same thread form geometry of the punch projection, and that the leg′ of the die′ has bigger dimensions than those of the legof the dieof the apparatus. These different features are provided to, e.g., without limitations, further reduce the pressure applied to the sidewallfor thread forming so as to reduce any possible damage to the can structure even more than the thread forming apparatusdoes.

It is to be appreciated that while the example embodiments described in detail herein are structured to create internal thread elements on can bodies (i.e., thread elements extending radially inward from the sidewall of the can body), such arrangements may be readily employed to create external thread elements on can bodies (i.e., thread elements extending radially outward from the sidewall of the can body) generally by switching the punch and die components described herein.

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.