THREAD FORMING APPARATUS AND ASSOCIATED METHOD

Abstract

A thread forming apparatus includes a punch assembly having a punch cam and a punch. The punch includes a body having a first end engaged with the punch cam and a second end having a projection moved radially in response to engagement with the punch cam. The apparatus further includes a die assembly adjacent the punch assembly and defining a clearance therebetween to receive a portion of a sidewall of a can body. The die assembly includes a die cam and a die including a top portion having a die recess and a bottom portion engaged with the die cam, the die being moved radially in response to engagement with the die cam. The 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.

Claims

1. 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, the thread forming apparatus comprising: 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.

2. The apparatus of claim 1, further comprising a number of actuators coupled to the punch cam and the die cam.

3. The apparatus of claim 2, wherein the number of actuators are structured to axially move the punch cam and the die cam.

4. The apparatus of claim 1, wherein the die further comprises a die guide structured to provide a linear guide to the die.

5. The apparatus of claim 1, wherein the punch further comprises a punch guide engaged with the punch body and structured to constrain movement of the punch body to linear motion.

6. The apparatus of claim 1, wherein the punch comprises a punch cam follower disposed at the first end of the punch body and engaged with the punch cam.

7. The apparatus of claim 1, wherein the punch cam is structured to slide axially parallel to a central axis of the can body.

8. The apparatus of claim 1, wherein to position the punch assembly and the die assembly for forming an internal thread on the can body, the punch cam is 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.

9. The apparatus of claim 1, wherein to form an internal thread, the punch cam is 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.

10. The apparatus of claim 1, wherein to release the can body, both the punch cam and the die cam are 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.

11. A method of forming one or more threads on a can body having a base and a sidewall extending from the base, the method comprising: 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.

12. The method of claim 11, further comprising removing the portion of the sidewall from the clearance.

13. The method of claim 11, further comprising: 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.

14. The method of claim 11, further comprising: 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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:

[0011] FIG. 1 is a partially schematic sectional view of an exemplary thread forming system including an exemplary thread forming apparatus in accordance with a non-limiting, example embodiment of the disclosed concept shown with a can body positioned adjacent thereto;

[0012] FIG. 2 is a perspective view of the thread forming apparatus and can body of FIG. 1;

[0013] FIG. 3 is a detail perspective, partially sectional, view of the thread forming apparatus and can body of FIGS. 1 and 2;

[0014] FIG. 4 is a side elevation view of the exemplary thread forming apparatus and can positioning mechanism of FIGS. 1-3;

[0015] FIG. 5 is a perspective view of the exemplary thread forming apparatus and can positioning mechanism of FIG. 4;

[0016] FIG. 6 is another sectional view of the thread forming apparatus and can positioning mechanism of FIGS. 1-5 shown with a can body prior to undergoing thread forming;

[0017] FIG. 7 is a sectional view, similar to FIG. 6, of the thread forming apparatus and can positioning mechanism of FIGS. 1-6, illustrating a can body undergoing thread forming in accordance with a non-limiting, example embodiment of the disclosed concept;

[0018] FIG. 8 is a sectional view, similar to FIGS. 6 and 7, of the thread forming and can positioning mechanism of FIGS. 1-7, illustrating a can body ready to be released after undergoing thread forming in accordance with a non-limiting, example embodiment of the disclosed concept;

[0019] FIG. 9 is an external side view of a can body positioned for thread forming by an exemplary thread forming apparatus in accordance with another non-limiting, example embodiment of the disclosed concept;

[0020] FIG. 10 is a sectional side view of the can body being positioned for thread forming by the exemplary thread forming apparatus of FIG. 9;

[0021] FIG. 11 is a perspective view of the sectioned area 101 from FIG. 10; and

[0022] FIG. 12 is a detail view of the area 101 of FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

[0023] 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.

[0024] As used herein, the singular form of a, an, and the include plural references unless the context clearly dictates otherwise.

[0025] 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].

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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].

[0031] 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.

[0032] As used herein, an elongated element inherently includes a longitudinal axis and/or longitudinal line extending in the direction of the elongation.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] FIG. 1 illustrates an exemplary thread forming system 1 having an example thread forming apparatus 100 in accordance with a non-limiting, example embodiment of the disclosed concept. The example thread forming apparatus 100 is shown throughout FIGS. 1-8. FIGS. 9-12 illustrate another example thread forming apparatus 100 having similar features as the example thread forming apparatus 100 except a few differences discussed further in detail with reference to FIGS. 9-12 below. As shown in FIG. 1, an example thread forming system 1 in accordance with the disclosed concept includes an example thread forming apparatus 100 for forming threads on a can body 10. The can body 10 has a base 12, a sidewall 13 extending axially from the base 12 (about a central longitudinal axis 3) and defining an interior 15. The sidewall 13 has a rim 14 opposite the base 12 that defines an opening (not numbered) in the can body 10 to the interior 15.

[0038] The thread forming apparatus 100 is structured to form threads at multiple points around a circumference of the sidewall 13 of the can body 10 generally adjacent the rim 14 and includes a punch assembly 102, a die assembly 104 and one or more cam actuators 106. The punch assembly 102 includes: a punch cam 108, which in the example shown in FIGS. 1-8 is structured to slide axially parallel to the central longitudinal axis 3 of the can body 10, and a punch 110. The punch 110 includes a punch body 112 having a first end 114 and an opposite second end 116. The punch 110 further includes a punch cam follower 118 disposed at the first end 114 of the punch body 112 and a punch projection 120 disposed at the second end 116 of the punch body 112. The punch cam follower 118 is engaged with the punch cam 108 and, in the example shown in FIGS. 1-8, is structured to move the punch body 112, and thus the punch projection 120, radially (with respect to central longitudinal axis 3) in response to axial sliding of the punch cam 108; between an initial punch position (as shown in FIG. 6) to a thread forming punch position (as shown in FIG. 7) thereof. The punch 110 further includes a punch guide 122 that is engaged with the punch body 112 and structured to constrain movement of the punch body 112 to linear motion perpendicular to the central longitudinal axis 3.

[0039] In some example embodiments, the punch cam 108 is a wedge cam and the punch cam follower 118 is a roller. In such example embodiments, as the punch cam 108 moves axially in parallel to the center longitudinal axis 3 of the can body 10, the punch cam follower 118 rolls along an angled cam face 124 of the punch cam 108. As the punch cam 108 moves axially toward the base 12 of the can body 10, the angled cam face 124 of the punch cam 108 causes the punch cam follower 118 to move in a radial direction toward the can body 10. As the punch cam 108 moves axially away from the base 12 of the can body 10, the angled cam face 124 of the punch cam 108 allows the punch cam follower 118 to move in a radial direction away from the can body 10. A biasing member 126 (e.g., a spring or other suitable member) may bias the punch body 112, and thus the punch projection 120 and the punch cam follower 118 in a radial direction away from the can body 10. In some example embodiments, the linear guide 122 may be lubricated to assist with smooth movement of the punch body 112. In some example embodiments, the linear guide 122 may be a portion of a cam guide 128.

[0040] The die assembly 104 is disposed adjacent to, but spaced a predetermined distance from, the punch assembly 102 and thus defines a clearance 4 (FIG. 3) therebetween that is structured to receive a portion of the sidewall 13 of the can body 10 such that the portion of the can body 10 is disposed between the punch assembly 102 and the die assembly 104. The die assembly 104 includes a die cam 130 coupled to a die cam rolling contact 132 (e.g., without limitation, a sphere) structured to move axially parallel to the central longitudinal axis 3 of the can body 10. The die assembly 104 also includes a die 134 having a top portion 136 having a die recess 138, a bottom portion 140, and a shaft 144 connecting the top portion 136 and the bottom portion 140. The bottom portion 140 includes an angled face 146. The die 134 is structured to move radially in response to axial movement of the die cam 130. For example, axial movement of the die cam 130 toward the base 12 of the can body 10 causes the die cam rolling contact 132 to press against the angled face 146 of the bottom portion 140 of the die 134 and move the die 134 radially toward the punch assembly 102. Axial movement of the die cam 130 away from the base 12 of the can body 10 allows the die 134 to move radially away from the punch assembly 102. A die guide 148 may be disposed around the shaft 144 of the die 134 to act as a linear guide for the radial movement of the die 134.

[0041] One or more actuators 106 are coupled to the punch assembly 102 and the die assembly 104 and are structured to axially move the punch cam 108 and the die cam 130. While FIG. 1 shows one actuator 106, this is for illustrative purposes only, and it will be understood that one or more actuators 106 (of any suitable arrangement(s)) may be employed without departing from the scope of the disclosed concept. For example, the punch cam 108 and the die cam 130 may be moved axially by a common actuator 106 or individual actuators 106 may be associated with the punch cam 108 and the die cam 130. The one or more actuators 106 may 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 actuators 106 are omitted from FIGS. 2-8 and 11-12 for economy of disclosure, but it is to be understood that one or more actuators 106 may be employed in any of the disclosed embodiments. In some example embodiments, the one or more actuators 106 may be actuated manually or automatically remotely via a user, workstation, or any other suitable arrangement communicatively coupled to the apparatus 100.

[0042] The punch projection 120 of the punch 110 has a male thread form geometry (e.g., a protrusion, a protuberance, a ledge or other thread form geometry), and the recess 138 of the die 134 has a female thread form geometry that is a negative of the male thread form geometry of the punch projection 120. With the sidewall 13 of the can body 10 disposed in the clearance 4 between the punch projection 120 and the recess 138, pressing the punch projection 120 into the recess 138 causes the can material therebetween to flow into the recess 138 and form an internal thread 11 (see FIG. 7) in the sidewall 13 of the can body 10. As its name suggests, the internal thread 11 projects inward from the sidewall 13 and has a shape corresponding to the punch projection 120 and the recess 138.

[0043] Formation of the internal thread 11 is generally shown in FIGS. 6-8. In FIG. 6, the punch cam 108 is disposed such that the punch projection 120 is next to the sidewall 13 of the can body 10 and the die cam 130 is disposed such that the recess 138 is next to the sidewall 13 opposite the punch projection 120. In this positioning, the internal thread 11 is ready to be formed. In some examples, the top portion 136 of the die 134 includes a sliding edge 150 so as to assist with positioning the sidewall 13 of the can body 10 in the clearance 4 between the punch projection 120 and the recess 138. FIG. 7 shows the internal thread 11 being formed. To form the internal thread 11, the punch cam 108 is moved axially toward the base 12 of the can body 10 such that the punch projection 120 is pressed radially toward the sidewall 13 of the can body 10 and into the recess 138 of the die 134, thus forming the internal thread 11. FIG. 8 shows the thread forming apparatus 100 releasing the can body 10. To release the can body 10, both the punch cam 108 and the die cam 130 are moved axially away from the base 12 of the can body 10 such that the punch projection 120 and the recess 138 move away from the sidewall 13 and the newly formed internal thread 11. In the position shown in FIG. 8, the can body 10 can be moved away from the thread forming apparatus 100, the thread forming apparatus 100 can be moved away from the can body 10, or both can be moved away from each other. Additionally, the can body 10 may be rotated on its central axis 3 if the same punch projection 120 and recess 138 will be used to form another internal thread 11 along the circumference of the sidewall 13 of the can body 10.

[0044] As noted above, in some example embodiments, the same punch projection 120 and recess 138 is used to form multiple internal threads 11. In some such embodiments, the thread forming apparatus 100 may include a single punch assembly 102 and a single die assembly 104. However, it will be appreciated that in some example embodiments, the thread forming apparatus 100 may include multiple punch assemblies 102 and multiple die assemblies 104 structured to be disposed around the circumference of the sidewall 13 of the can body 10. In such embodiments, a single thread forming operation may form multiple internal threads 11 around the circumference of the sidewall 13 of the can body 10.

[0045] In some example embodiments, the die guide 148 further includes a leg 152 extending axially inwardly into the interior 15 of the can body 10 and is structured to hold the top portion 136 of the die 134 upon radially retracting the die 134 from the sidewall 13 of the can body 10 as shown in FIG. 8.

[0046] In some example embodiments, the die 138 includes a biasing member 154 (e.g., a spring) structured to bias the die 134 radially toward the central axis 3 of the can body 10. The biasing members 126 (previously discussed) and 154 cause the punch 110 and die 134 to move away from each other and the sidewall 13 of the can body 10 when not being pressed toward the sidewall 13. In some example embodiments, the one or both of the biasing members 126 and 154 may be omitted and additional cams may be employed to move the punch 110 and die 134 away from the sidewall 13. For example, a first cam may be employed to move the punch 110 toward the sidewall 13 and a second cam may be employed to move the punch 110 away from the sidewall 13, and a similar arrangement may be employed with the die 134 without departing from the scope of the disclosed concept.

[0047] In some example embodiments, the punch cam guide 128 may have a contour that corresponds to the exterior contour of the sidewall 13 of the can body 10, as shown for example in FIG. 2. Similarly, the die guide 148 may have a contour that corresponds to an interior contour of the sidewall 13 of the can body 10, as shown for example in FIGS. 3 and 5.

[0048] It will be appreciated that in some example embodiments, the axially moving punch cam 108 and/or die cam 130 may 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 cam 108 and/or die cam 130. For example, in an embodiment with multiple die assemblies 104, a lobed shaft may be placed along the central axis 3 of the can body 10. Rotation of the lobed shaft causes the lobe of the lobed shaft to sequentially actuate each die 134 individually. A cylindrical structure with a lobe can similarly be employed to actuate the punches 110. Coordinated rotation or coupling of the lobed shaft and cylindrical structure would result in synchronized actuation of corresponding dies 134 and punches 110.

[0049] FIGS. 9-12 illustrate an exemplary thread forming apparatus 100 in accordance with a non-limiting, example embodiment of the disclosed concept. The thread forming apparatus 100 is similar to the thread forming apparatus 100 of FIGS. 1-8, except that the top portion 136 of the die 134 does not include a sliding edge 150 of the thread forming apparatus 100, the recess 138 of the die 134 is wider than the projection 120 of the punch 110 such that an internal thread formed therebetween may not have the same thread form geometry of the punch projection 120, and that the leg 152 of the die 134 has bigger dimensions than those of the leg 152 of the die 134 of the apparatus 100. These different features are provided to, e.g., without limitations, further reduce the pressure applied to the sidewall 13 for thread forming so as to reduce any possible damage to the can structure even more than the thread forming apparatus 100 does.

[0050] 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.

[0051] 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.

[0052] 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.