Patent Grant
10857586
This invention relates in general to sheet metal manufacturing processes, and more particularly to systems and related methods for manufacturing ring pull bottle crowns.
A beverage bottle that opens manually with relative ease, without the use of a bottle opener, has been a long-felt need for beverage providers. Bottle caps must be tightly secured to the bottle opening to prevent spillage of the contents, loss of pressure (in the case of pressurized or carbonated beverages) and to maintain the hygienic conditions of the contents. The tight seal makes it difficult to open a bottle by hand.
Caps, also referred to interchangeably as crowns, are secured to the bottle opening by crimping the crown down over the open of the container in a series of concave arcs around the circumference of the opening. The arcs create sharp convex points between each concave arc. The arcs and points are often referred to by those skilled in art as “angles” or “flutes.”
The advent of the familiar twist-off bottle cap was a significant advance for manual bottle opening, but all too frequently one has to grip the cap so hard to twist the cap free that the points of the cap angles inflict pain on the hands or fingers. To protect the hands from injury, it is a common practice to wrap the bottle cap in the tail of a shirt or in a cloth before twisting the cap.
Bottle caps adapted with pull tabs, similar to those used for beverage cans, have been known in China and other territories of Asia. See, for example, International Patent Application PCT/CN00/00040 by Liu, priority date Mar. 4, 1999, International Publication No. WO00/51906. Such ring pull crowns, however, are notoriously difficult to open because they require the exertion of an uncomfortable amount of force to break the seal and then pull the tab back (tearing the metal) to remove the cap.
Another pull tab solution for bottle caps is known as the MAXICROWN® such as is described U.S. Pat. No. 4,768,667, issued Sep. 6, 1988, to Magnusson. The MAXICROWN® provides a pull ring disposed along the side of the neck of the bottle as an extension of the crown and thus is problematic for use with standard angle-crimping bottle capping machines. Indeed, a special capping machine is recommended to cap bottles with the MAXICROWN®.
There is a need, therefore, for a bottle crown that is easy to open manually yet which may be tightly sealed around the bottle opening using standard bottle capping machines common in the art. Accordingly, there is also a need for an efficient process for manufacturing such a bottle crown.
In accordance with one aspect of the present invention, systems and related methods for manufacturing ring pull bottle crowns is provided which substantially eliminates or reduces disadvantages associated with previous systems.
In accordance with one embodiment, a method of manufacturing a ring pull crown is provided. The method includes the steps of forming crown bodies from a first source material, forming pull ring and tab assemblies from a second source material, and combining the crown bodies with the pull ring and tab assembles to form ring pull crowns. The method further includes the steps of forming a circumferential skirt around the ring pull crown and removing the ring pull crowns from the first source material. According to another embodiment, a system is provided that has one or more machines arranged and adapted to carry out the steps of the above method.
Other embodiments may be employed with containers for products other than a beverage, such as soup or stew, where a large mouth opening provides easy access to the contents. In addition, in other embodiments, ring pull crowns may be manufactured in accordance with the disclosed principles for containers such as medical vials or other small mouth containers. In short, the principles disclosed herein may be employed to manufacture ring pull crowns and lids for any size or type of containers.
One advantage of the systems and related methods for manufacturing ring pull bottle crowns, is that production equipment can manufacture the ring, tab, rivet, and cap using a single machine. Alternatively, a set of machines may be used as well. Another advantage of the invention(s) disclosed herein, is that a pull ring can be produced in a separate color from the crown body. Yet another advantage is that printed material can appear on the crown surface, rivet, and corrugation.
For a more complete understanding of the present invention and its advantages, reference is now made to the following description and the accompanying drawings, in which:
In view of the foregoing, through one or more various aspects, embodiments and/or specific features or sub-components, the present disclosure is thus intended to bring out one or more of the advantages that will be evident from the description. The present disclosure makes reference to one or more specific embodiments by way of illustration and example. It is understood, therefore, that the terminology, examples, drawings, section headings, and embodiments are illustrative and are not intended to limit the scope of the disclosure. The terms “crown” and “cap” may be used interchangeably in the description that follows.
Skirt 106 descends from top 110 along the external perimeter of crown 100 and in specific exemplary embodiments smoothly merges into a downwardly and radially outwardly extending flange. The skirt 106 is preferably adapted to be crimped onto the neck of a bottle for sealing. Specific exemplary embodiments of skirt 106 are divided into undulating, repeating portions that define the flutes 102 and lands 112. Preferably, the repeating portions are circumferentially evenly spaced apart such that each flute 102 is identical to all other flutes 102 around the circumference of the crown 100, and each land 112 is identical to all other lands 112 around the circumference of the crown 100. It should be understood that the crown 100 may include any number of flutes 102 and lands 112.
Moreover, the length of the skirt 106 extending below the top surface of the crown body may be of any length for use in bottle capping or other applications, which includes “short height” crowns, “intermediate height” crowns, or “standard height” crowns for use on bottles or other containers having openings with a variety of lips sizes configured to receive the crown. For example, industry standards typically refer to “standard height” crowns as those having a height, as measured from the top surface of the crown to the bottom edge of the skirt, of about 6.4-6.6 mm±0.15 mm, “intermediate height” crowns as those having a height of about 6.0-6.2 mm±0.15 mm, and “short height” crowns as those having a height of about 5.0-5.2 mm±0.15 mm. Moreover, as mentioned above, crowns manufactured in accordance with the disclosed techniques includes the manufacture of crowns of any size and for any container application, such as diameters between 26 mm and 29 mm, or even smaller or larger diameters. Thus, no limitation to any particular crown or skirt shape, style or size should be implied in the present disclosure. Likewise, the presence of a corrugated skirt on a crown manufactured in accordance with the disclosed principles is not required, and instead a smooth skirt, such as those used in the medical vials or similar applications, may also be formed with the disclosed manufacturing principles.
A ring pull crown 100 may be secured to a container by crimping the skirt 106 around the circular outer lip edge of the container. The crown body 110 may also include a rubber or plastic liner on the bottom side of the cap (not shown in
Score lines 104 (also referred to herein as “score lines”) generally taper inward from the skirt edge 103 toward the approximate center of crown 100 to provide a tapered tearing groove along the outline of a wedge-shaped tongue 111. For example, the depth of the tapered groove may graduate from a depth in the range of approximately 0.03 to 0.02 mm near the skirt edge of crown 100 to a depth in the range of approximately 0.10 to 0.08 mm by rivet 153 near the center of crown 100. In a preferred embodiment, one of the score lines 104 provides an S-curve or tail segment 109 that extends along the skirt 106 of crown 100. The S-curves are advantageous in that they permit the torn portion of the crown to remain attached to the remainder of the crown body. In other embodiments, however, the score lines 104 may also be formed straight, if desired.
By varying the depth of the score along cutting line 104, crown 100 provides a tearing groove which makes it more likely that only a reasonable amount of manual force is called upon to tear open crown 100. As will be discussed in more detail below, a recommended range of dimensions and material composition of crown 100 are disclosed to further provide a crown that may be manually opened with only reasonable force.
The present disclosure contemplates alternative degrees of divergence of score lines that instead converge toward rim 103. The score lines may even be substantially parallel, convergent, or divergent, and the selected degrees or angle separating the lines, is a matter of design choice, as is the number of score lines, which may be as few as one or even zero. Accordingly, the present invention contemplates all and every permutation of score lines which may be selected for the engineering design of a particular crown.
In a preferred embodiment, one of the score lines 104 provides an S-curve or tail segment 109 that extends along a portion of the skirt 106 of crown 100. S-curve 109 may facilitate the removal of crown 100 from a container opening. In operation, a person tears from the center of the cap along score lines 104. When the tear reaches S-curve 109, the tearing force follows the S-curve away from cut line 104 and impels the tear along the opposite cut line 104 to terminus 109 which breaks open crown 100. Continued tearing force along S-curve 109 pulls the portion of the skirt 106 away from the container opening (not shown) and releases crown 100 from the container (not shown). S-curve 109 consists of a scoring line having an upper radial segment extending from the opener assembly to the skirt 106 along a radial axis and a lower annular segment extending circumferentially along the skirt 106 in an annular direction and extending from a terminus of the upper radial segment, the lower annular segment defined in a second horizontal plane equidistant to the first horizontal plane associated with the lower edge of the skirt 106.
The pull ring and tab assembly 150 is connected by a rivet 153 to the tip of the tongue 111 of the crown body 110 in order to facilitate easy opening of the crown 100 along the score lines 104. The pull ring and tab assembly 150 includes a pull tab 151 that is connected to a pull ring 156 at the pull tab's fulcrum end 154. In preferred embodiments, the pull tab 151 may be embossed or printed with an instructional symbol 152 (e.g., a bent arrow) that suggests the manner of opening the crown 100. Further instructions may be provided with printed instructions, which may read, for example: “LIFT RING PULL UP TO REMOVE.” Additionally a caution warning may be printed on crown 100. The other end of the pull tab 151 has a rivet hole that permits the pull ring and tab assembly 150 to be joined with the crown body 110.
The center portion of the crown 100 may also include recessed concentric subsections that enable the pull ring and tab assembly 150 to sit within the crown body 110 substantially flush with the crown shoulder 101. One of the advantages of a ring pull crown 100, arranged as depicted in
To open the ring pull crown 100, a user may insert a fingertip or fingernail (or some other lever object) under the pull ring 156 and lift up on the pull ring 156 to separate the tip of the tongue 111 from the crown body 110. In certain preferred embodiments, such as the embodiment depicted by
When the end of the pull ring 156 opposite the fulcrum cut 154 is lifted upward and away from the crown body 110, the imaginary plane formed by the pull ring 156 acts as a first lever that rotates about the axis formed by the two points of the fulcrum cut 154. As the pull ring 156 rotates upwards, the end of the pull tab 151 nearest the fulcrum cut 154 is lifted from the surface of the crown body 110. The pull tab 151 then acts as a second lever arm that applies upward force to the rivet 153 located at the opposite end. The rivet 153 transfers the upward force to the tongue 111 of the crown body 110 sufficient to separate the tongue 111 from the crown body 110 via the score lines 104. Once the tip of the tongue 111 has been initially separated from the crown body 110, the user may insert his or her finger through the pull ring 156 and use it to easily tear the remainder of the tongue 111 from the crown body 110 along the tear lines 104. Importantly, as shown in
In particular, tinplate material which demonstrates an approximate hardness of T4 on the Rockwell 30T Hardness Scale is preferred for the exemplary cap illustrated in
A pulling force for a pull ring of the present disclosure of approximately 2.5 kg (kilograms) or less is preferred. A relatively small pull force such as this is recommended so that virtually everyone will have sufficient strength to open a bottle using a crown of the present disclosure. In contrast, a relatively large pull force has the disadvantage of requiring a great amount of initial force to tear the tinplate material, and once the tinplate is torn open the sudden release of pulling force causes the bottle to jerk away from the user, spilling the contents often in dramatic fashion.
In addition to the low hardness of the tinplate, the thinness or gauge of the crown may also contribute to achieving a small pull force. For example, a crown of the present invention is recommended to have a thickness of less than 0.28 mm. For example, typical bottle crowns have a thickness of about 0.21 mm. Embodiments in which the crown material is strengthened by corrugation, such as in seated embodiments, may be thinner than standard crowns, having, for example, a gauge as thin as approximately 0.16 mm and even as thin as 0.12 mm.
In addition to the foregoing embodiments described above, an additional embodiment provides a reduced gauge crown that delivers additional advantages. Billions of bottle caps are used worldwide and the cost of the caps is largely determined by the amount of material required for the caps. One way to reduced such costs is to reduce the amount of material used in each crown. The amount of material can be reduced by making the crown thin, or reducing the gauge of the crown. A reduced gauge could be achieved by using less material but this might compromise the integrity of the crown by making the crown weaker. Another approach would be to use less material but use a stronger material. However, stronger materials might be more expensive than standard tinplate typically used in crown manufacture, which would defeat the cost savings purpose. An approach that reduces the amount of material but uses the same material without compromising strength is to corrugate the crown.
In an alternative embodiment (not shown), one or more spoilage indicators, such as dimples depressed in crown 100, may be positioned so as not to be obscured by the pull ring apparatus of the present disclosure. For containers that are vacuum sealed, spoilage indicators pop up in the event that the pressure seal is lost.
Skirt 303 descends from shoulder 301, which is contiguous with top 310. Seat 313 is of sufficient depth that pull ring 350 is substantially flush with the top 310 of crown 300. Such an embodiment advantageously is suitable for use in conventional bottle capping machines without having to re-tool or refit the machine. A further advantage of seat 313 is that seat 313 forms a corrugated perimeter around the seat and corrugation is well known to strengthen flat sheets against bending in directions substantially perpendicular to the direction of corrugation. Seat 313, therefore, provides the additional advantage of strengthening crown 300. A further advantage of a strengthened crown 300 as provided by seat 313 is that the thickness of crown 300 may be reduced to a lower gauge (thinner) crown material than would be utilized in a standard crown, thus lowering the costs of manufacturing materials.
In alternate embodiments, seat 313 may be shallower so that pull ring assembly 350 is seated slightly or partially above the shoulder 301 of crown 300. Such an embodiment may provide the advantage of having pull ring 350 easily accessible for manual opening. Depending on the acceptable tolerances, such an embodiment may also be suitable for use with a standard bottle capping machine.
In the exemplary embodiment shown in
In some embodiments, the stiffness and compressive strength of crown body 400 may be improved through corrugation. As shown by
Corrugation strengthens materials. This is particularly true of laminar materials formed into a sheet or plane. A laminar product can use less of a material if the material is corrugated to provide lateral strength. A bottle cap is a laminar product in which the sheet material, often steel or tinplate, is shaped to be affixed to the top of a bottle or other container. A standard pry-off or twist-off cap has a thickness of material that is predominantly determined by considerations of leak prevention and the secureness of the attachment of the cap to the container. Corrugation allows caps that use less material to have the equivalent strength of a standard thick crown. A corrugated crown is thinner, that is, it has a reduced gauge, in comparison to a standard bottle cap. An advantage of such a “reduced gauge crown” (RGC) is the money savings obtained by using less material.
Another advantage of a reduced gauge corrugated cap comes into play with innovated “pull-off” caps, which have a pull tab assembly attached to the crown as described herein. The pull tab breaks the cap material and the crown is torn off the bottle using the pull ring of an opener assembly. A reduced gauge crown facilitates the tear off because the cap material is thin and the tearing action is parallel to the direction of material strengthening provided by the corrugation and therefore the tearing force does not have to overcome the material strengthening of the corrugation. Corrugation affords material strengthening perpendicular to the direction of corrugation.
In addition to the structures illustrated in the figures herein, it is understood that other structures will imbue a cap of the present disclosure with the advantages of corrugation and provide a reduced gauge crown for a bottle. For instance, concentric rings, which progress from the top of the skirt toward the center of the seat, and decorative shapes such as stars, brand logos, sports team logos, religious insignia, and the like, formed in the plane of the cap, are embraced in the present disclosure.
Corrugation forms may be provided to a bottle cap by a variety means, including without limitation, metal stamping, pressing, embossing and so forth. Non-metal crowns of the present disclosure may be formed by injection molding for plastic crowns, or by other suitable means of production. In addition, non-metal materials may also be used to form the ring and tab assembly either a part of the disclosed manufacturing process, or as a prior process that provides the formed ring and tab assemblies for mounting on the disclosed crown bodies. The use of non-metal materials in combination with the disclosed manufacturing techniques is discussed in further detail below.
In preferred embodiments, the edges of the pull ring 501 should be blunted in order to reduce the risk a person might cut his or her finger while opening a container using the pull ring. For example, as shown in
The pull ring and tab assembly 500 may be formed from a variety of suitably stiff, inexpensive materials, such as: tinplate, steel, aluminum, or plastic. If a metallic material is used, the thickness of the material may be thinner than the material used for the crown body in order to reduce per unit costs.
In certain preferred embodiments, a die press may be used to form the crown body or pull ring and tab assembly. A die is a metal block that is used for forming materials like sheet metal and plastic. For the forming of sheet metal, two parts may be used: one, called the punch, performs the stretching, bending, and/or blanking operation, while another part, called the die block, securely clamps the workpiece and may provide similar stretching, bending, and/or blanking operation. The workpiece may pass through several stages using different tools or operations to obtain the final form. After the main forming is done, additional crimping or rolling operations may be performed to ensure that all sharp edges are hidden and to add rigidity to the various pieces being manufactured.
The crown body manufacturing process 610 begins at step 611 when a crown body sheet 700 is fed into a manufacturing system configured to carry out the manufacturing process 600. As illustrated, the crown body sheet 700 may be preprinted or pre-stamped with any number of colors, logos, writing, embossing, etc. as desired for the specific application of the crowns being manufactured. In step 612, the crown body sheet 700 is separated (sometimes referred to as “guillotined”) into individual rectangular crown strips 701. During step 612, the ends of each strip 701 may be further punched out to form scalloped edges that aid in strip alignment. The individual crown strips 701 are then rearranged end-to-end and fed into equipment configured to form the crown bodies on each crown strip 701. Such pre-staging steps may be useful for providing a continuous feed of crown body source material to subsequent crown body formation steps (e.g., by conveyer line); however, such pre-staging steps may be altered or even omitted without departing from the scope of the present disclosure.
In steps 613 through 616, one or more crown bodies are formed in a series of stages using various die punches or similar manufacturing tooling. In step 613, a punch is used to form one or more score lines 104 on the crown body strip 701. In step 614, a punch is used to form a rivet or a rivet hole of a crown body. In step 615, the crown body may be embossed with features such as recessed portions, dimples, and/or seal indicators. In step 616, the crown body is trimmed. Each of these manufacturing steps will be described in further detail below, and should be understood throughout this disclosure that a greater or fewer number of steps may be included in a manufacturing process provided in accordance with the disclosed principles.
The pull ring and tab assembly process 620 begins at step 621 when a ring and tab assembly sheet is fed into equipment configured to form one or more pull ring and tab assemblies on the sheet. In one embodiment, the sheet is actually a coil or band material provided to the equipment disclosed herein, however, other types of source material for the ring and tab assemblies may also be employed. In step 622, a blanking punch may be used to cut ring and tab outlines. In step 623, the pull tab may be optionally embossed with features such as instructional symbols. In step 624, one or more punches may be used to form a rivet recess and rivet hole. In step 625, one or more punches may be used to stamp fold lines for the pull ring and to fold the stamped edges downwards. In step 626, one or more punches may be used to stamp fold lines for the pull tab and to fold the stamped edges downwards. In step 627, the ring edges and tab wings are curled and smoothed. As with the crown body formation, each of these manufacturing steps will be described in further detail below, and should be understood throughout this disclosure that a greater or fewer number of steps may be included in a manufacturing process provided in accordance with the disclosed principles.
The pull ring and tab assembly formed by process 620 is cut from the ring and tab sheet. In step 631, the formed pull ring and tab assembly is aligned with a corresponding crown body, which is still attached to a crown body strip 701. In step 632, the ring and tab assembly is attached to the crown body by using an independent rivet or by compressing the ring and tab assembly onto a rivet formed on the crown body itself. In step 633, the skirt of the assembled ring pull crown is formed and corrugated with fluted angles, or with a smooth skirt if the application calls for it. In the same or subsequent step, the completed ring pull crown is trimmed from the crown body sheet.
Arranged using such a pattern, the center points of any three adjacent crown body blanks 702 will form the vertices of an equilateral triangle, and a ray coextensive with a diagonal row of blanks 702 will form a sixty degree angle with the long edge of a crown body strip 701. Of course, other design or engineering factors may dictate that a different circle-packing patterns be used, such as: trihexagonal, square, elongated triangular, snub square, etc.
The type of material to be used for the crown body sheet depends in part on the type of ring pull crown to be manufactured. Specific embodiments of the corrugated crown caps described herein, such as embodiments for pry-off or twist-off, are formed with steel of increased hardness compared with conventional crown caps presently in commercial production. For example, conventional crown caps are often formed of single reduced, T4, tinplate having a thickness of from 0.21 mm to 0.23 mm. Such tinplate has an average hardness (that is, the reported hardness value regardless of +/−variations) of approximately 61 on a 30T hardness scale, in accordance with ASTM 623. Crown caps 100 described herein may be made thinner and lighter weight compared with the prior art, for example, crown caps may be formed of a material having a thickness of about 0.19 mm to 0.28 mm, or even as thin as 0.16 mm, that have the same or roughly equal performance as conventional, thicker caps. These decreases in metal usage are more easily achieved when the structure of crown caps 100 are made with steel having increased hardness. For example, the inventor has demonstrated the effectiveness of low gauge crowns having grooves using DR8 (according to ASTM 623) or DR550 (according to EN 10203). Optionally, the inventor surmises that other materials may be used, such as single reduced tinplate or like material having enhance tempering, tin-free steel having similar properties as those described herein, and the like.
The crowns 100 preferably have an average hardness of greater than 62 on the 30T scale (conforming to ASTM 623), more preferably greater than about 65, or even greater than about 68 or about 71, if the application calls for it. Some embodiments were demonstrated to be effective using steel having a hardness of 73. The upper limit of hardness is set by the maximum stress acceptable to the glass bottle during the crimping process or the spring back (which may tend to urge the crimped flanges toward an uncrimped state) associated with harder plate. Because hardness has a relationship to strength as reflected in the yield point, the aspect of the hardness of the crown may be expressed in yield point on a corresponding scale. For example, DR8 or DR550 tinplate may has a yield point (in a tensile test) of 550 MPA.
However, it will be understood that for pull tab opener embodiments, softer materials, such as softer tinplate than T4, or even aluminum for medical vial or other cap applications requiring aluminum or other soft metals, are advantageous because they facilitate ease of opening and tearing. The strength provided by corrugation permits the use of a relatively soft crown material while preserving the strength required for secure closure of the container. The inventor believes that the most advantageous crown cap embodiment has a combination of strength for secure closure and softness for ease of opening and tearing that is a matter of design and engineering choice. A crown of the present disclosure encompasses crown caps that do not have all of the structure, materials, and/or advantages in this specification.
According to this description, commercially acceptable crown caps formed according to the present disclosure can be commercially made with up to 25 percent less material (e.g., steel or tinplate) compared with many conventional crown caps, which has corresponding advantages in carbon emissions. The savings in material weight are approximately proportionate to the reduction in metal thickness. Further, even though energy required to cool an individual crown is tiny, the energy required to cool the total number of crowns produced each year (approximately 60 billion in North America and approximately 300 billion throughout the world), and the corresponding reduction in that energy, is significant.
The reduced gauge crown (RGC) discussed above has an impact on reducing the cost of the tinplate or steel, and the PVC, PVC-free, or oxygen scavenger liner material, which is available with an additive, making both the metal crown and PVC, PVC-free, or oxygen scavenger liner, biodegradable in an “active landfill”. With the resulting lower production and weight in transportation costs in the RGC, in turn, reduce CO2 emissions. Tinplate or steel used to produce crowns for the beer or soda industry varies between 0.18 mm-0.24 mm. The present reduced gauge crown may use a thickness of between 0.12 mm-0.19 mm. A standard pry-off or twist-off crown, weighs approximately 2.38 grams, whereas the reduced gauge crown weighs approximately 2.14 grams, a 10% reduction in weight yielding a savings in material costs.
A further benefit of the reduced gauge crown is seen in the transportation costs of crowns. A reduction in weight relates to a savings in transportation fuel costs, wear and tear on the transportation vehicles, and reduced transportation carbon dioxide emissions. Standard bottle crowns are traditionally packed 10,000 per carton but with a reduced gauge crown embodiment, a carton holds 11,000 crowns, thus providing reduced energy, transportation, and carbon dioxide emissions. Thus, advantages of the reduced gauge crown embodiment include, without limitation, cost savings in production, lower price per crown, lower transportation costs, lower loading costs, as well as reduced carbon dioxide emissions.
In addition to all of the embodiments described herein, an additional feature is suitable for use with of each of the embodiments as a matter of engineering, design or marketing choice, which is the employment of temperature-sensitive color-changing ink, so-called thermochromic ink, such as described, for example, in U.S. Pat. No. 6,634,516 to Carballido, which is incorporated herein by reference in its entirety. Such thermochromic inks have the property of changing color so as to be one color at room temperature (approximately 21° C.) and a different color when refrigerated to, for example standard retail refrigeration temperature of 4° C. In an exemplary application, the ink is transparent, for example, at room temperature but becomes relatively opaque and visible at chilled temperature, such that a customer has visual confirmation of the approximate temperature without touching the container.
In preferred embodiments, the sheet metal used to form the crown bodies may include a scalloped edge on the ends of cut sheets for sheet material gap “nesting” during production. Additionally, such sheets may be cut in the same equipment as other parts of the manufacturing process disclosed herein, or may be pre-cut prior to being provided into equipment configured for the manufacturing process disclosed herein. Both ends of pre-printed or unprinted sheet of material would have scalloped edges punched out prior to feeding of the sheets for crown and tab production. Scalloped ends allows precision alignment from one cut sheet to the next as each sheet is fed into the crown body stamping portion of the manufacturing equipment. It should be noted that the scalloped shapes illustrated is only exemplary, and any advantageous shape of the ends of the sheets of material, or no scalloping at all, may be employed with the disclosed principles. Moreover, although cut sheets of material for the crown body are illustrated herein, the disclosed principles may also be implemented with rolled material or any other means for providing such material for crown stamping.
Progressive stamping is a metalworking method that can encompass punching, coining, bending, and several other ways of modifying metal raw material, combined with an automatic feeding system. The feeding system pushes a strip of metal through all of the stations of one or more progressive stamping dies. Each station performs one or more operations until a finished part is made. The final station is a cutoff operation, which separates the finished part from the carrying web. The carrying web, along with metal that is punched away in previous operations, is treated as scrap metal. Both are cut away, knocked down (or out of the dies) and then ejected from the die set, and in mass production are often transferred to scrap bins via underground scrap material conveyor belts.
One or more progressive stamping dies are placed into a reciprocating stamping press. As the press moves up, the top die moves with it, which allows the material to feed. When the press moves down, the die closes and performs the stamping operation. With each stroke of the press, a completed part is removed from the die. Since additional work is done in each “station” or “stage” of the die, it is important that the strip be advanced very precisely so that it aligns within a few thousandths of an inch as it moves from station to station. Bullet- or conical-shaped “pilots” may be used improve alignment beyond what is provided by the servo feeding mechanism.
Each die may be made of tool steel to withstand the high shock loading involved, retain the necessary sharp cutting edge, and resist the abrasive forces involved. In certain preferred embodiments, groups of die stamps may be configured to work together. For example, a first group of six stamps may stamp the sheet material while a second group of six stamps representing a subsequent die stage stamp the sheet material simultaneously. Such grouping allows one group to provide one part of the crown body stamping process, while another provides a later part of the crown body stamping process. Of course, a greater or lesser number of stamps may be so grouped, or only a single grouping of all stamps may be provided during the stamping of the crown body.
Returning to the manufacturing step depicted by
In the same step, or in a prior preliminary step, of forming the score lines 104. a blanking die may also be used to trim the outline of a crown. It should be noted, however, that the order of steps performed in the illustrated embodiment disclosed herein are merely exemplary, and therefore scoring or other steps in the disclosed process may occur in different order without deviating from the scope of the disclosed principles.
In addition to rivet formation, the same or a subsequent die may be configured to form corrugated ridges (402, 407) and recesses (404, 405), as seen in
The pull ring and tab section may be produced from a coil of appropriate material, such as metal or plastic, or may be produced from cut sheets of material similar to that used for the crown body production. Of course, no limitation to the source material, or its shape, is intended or should be implied and the disclosed production equipment and process may advantageously be employed with any type of appropriate material(s).
In alternative embodiments, a pull ring and tab assembly may be formed from a plastic material using plastic forming techniques, such as: injection molding, blow molding, or compression molding. For example, in injection molding, melted plastic, for example resin plastic, may be forced into a mold cavity. Once cooled, the mold is removed. Thus, for plastic embodiments, rather than employing traditional sheet metal dies and punches, the disclosed principles may include plastic injection equipment or other plastic formation equipment in place of the die and punch equipment illustrated herein. In such embodiments, the plastic formation equipment would substitute the die and punch equipment described below so that the non-metal assemblies may be manufactured in their place. Moreover, the disclosed principles include those embodiments where the pull ring and tab assemblies are preformed in a separate process, and such preformed assemblies are fed into the disclosed manufacturing process for attachment to the crown bodies.
In the illustrated embodiment, the pull ring and tab assembly manufacturing process 1010 progresses from north to south. Each formative stage for the pull ring and tab assembly is arranged in a diagonal row. Many of the conventional manufacturing techniques for forming pull tabs use different patterns for arranging the pieceworks within the carrying web. Compared with conventional pull tabs, the size and shape of a piecework for a pull ring and tab assembly is generally larger and more circular. Existing methods of attachment, which were design for a small pull tab, will not work for the larger pull ring and tab assemblies. Thus, a different pattern is needed for arranging pull ring and tab assemblies in such a way that minimizes carrying web scrap, is scalable depending on the number of piecework dies used for each die stage (e.g., 2, 3, 4, 6, or 8), and is oriented in such a way that a completed pull ring and tab assembly may be efficiently attached to a corresponding crown body. As shown in
Returning to the arrangement of processes illustrated by
One advantage of using a diagonal stamping process for combining the pull ring and tab assemblies and crown bodies is that a simpler reciprocating system may be used to drive the attachment die stage. An entire diagonal row of pull ring and tab assemblies may be joined with an entire diagonal row of crown bodies in a single compressive motion. This simplifies the timing and alignment of the two parallel processes in that each process advances one entire stage between successive compressions. This unique process provides not only an advantage in saving time as an entire diagonal row of pieceworks may be combined in a single operation, but also an advantage in saving space as the beneficial arrangement of crown bodies, and thus the corresponding angular alignment of pull ring and tab assemblies, disclosed herein allows the smallest die press for combining the two pieceworks for the given number of crown bodies and ring and tab assemblies being combined.
Once these two portions are combined to form single, completed crown 1202 (such as the crown illustrated in
During the corrugation, the stamps may also provide a desired curvature, as well as flutes if desired, to the skirt area of the crowns to create a skirt configured to be received around an opening, such as the top of a bottle selected to receive a completed crown constructed in accordance with the disclosed principles. In the illustrated embodiment, skirts with flutes are formed in the finished crown assemblies 1204, for example, for use in typical bottle cap applications. However, in other embodiments, the skirts may be free of any flutes and may instead be given a smooth surface.
Additionally, the same stamps may be used to form the skirt areas of the crowns 1204 may also be used to punch the completed crowns 1204 from the sheet material. In other embodiments, a separate set of stamps may instead be used to separate the completed crowns 1204 from their sheet material. Further, in some embodiments, bottom portions of the set of stamps used to remove the assembled crowns from the sheet material may also provide a liner material to an underside of the crowns during creation of the skirt. Alternatively, the liners may be added in a subsequent process with subsequent equipment.
In accordance with one embodiment,
The hydraulic guillotine 1317, which may be powered by a hydraulic power unit 1316, is fed by an automated sheet feeder 1315 connected to a driven roller platform 1312. Printed crown body sheets 700 are deposited on the driven roller platform 1312 by a machine operator or by another automated process. The automated sheet feeder 1315 buffers a crown sheet 700 before it is fed synchronously into the hydraulic guillotine 1317. The hydraulic guillotine 1317, or a similar device, may also be responsible for forming the scalloped edges on each crown body strip. Excess scrap from the cutting and scalloping process would be deposited in a scrap bin for trims 1326 conveyed by magnetic scrap removals 1320. The cut strips exit the guillotine 1317 and are moved by a magnet belt 1319 to strip stacker 1322, which stacks the strips. One the stacked strips reach a predetermined number, the stack is moved down the line to a buffering station 1323 before being eventual fed into the next subsystem via the lifting table/non-stop feeder 1324.
The subsystem 1350 receives a stack of crown body strips from strip feeder 1370 as input to the de-stacker component 1353. The de-stacker 1353 sequentially feeds the crown body strips via conveyer into the first multi-stage die system 1360, which is used to create the one or more crown bodies on the strip feed. A positive conveyer speed differential between the strip feeder 1353 and the conveyer of the crown push servo feed 1354 may be used to remove gaps between strips. In preferred embodiments where the ends of each strip have scalloped ends, the de-stacker and strip feeder 1353 will also ensure proper alignment of the edges such that the trailing edge of a first strip nests within the leading scalloped edge of a subsequent strip.
The pace of the continuous strip feed is controlled by a crown push servo feed 1354. A servomechanism, sometimes shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the performance of a mechanism and is defined by its function. It usually includes a built-in encoder. A servomechanism is sometimes called a ‘Heterostat’ since it controls a system's behavior by means of Heterostasis. The term applies to systems where the feedback or error-correction signals help control mechanical position, speed or other parameters. As the crown push servo 1354 advances a crown body strip, a first multi-stage die system 1360 forms one or more crown bodies on the crown body strip. For example, a series of die stages may create score lines, form a rivet or rivet hole, emboss the crown body with recesses or dimples, and pre-cut the crown body from the sheet.
Simultaneous with the creation of the crown body, a separate, parallel manufacturing process is used to form the pull ring and tab assembly. A ring and tab coil 1380 provides a continuous input of tinplate to this second process, which is controlled and advanced by the tab servo feed 1354. Much like the crown body creation process, a second multi-stage die system 1361 may be used to form on or more pull ring and tab assemblies on the tinplate feed. For example, a series of die stages may cut ring and tab outlines, emboss tabs, form rivet holes, fold ring edges, fold tab edges, and curl or smooth the folded edges.
In the exemplary equipment 1350 illustrated by
In alternative embodiments, the second multi-stage die system 1361 for forming metallic pull-ring and tab assemblies could instead be replaced by a plastic molding machine, such as an injection molding process. Alternatively, the pull ring and tab assemblies could be pre-manufactured and simply combined with the crown bodies using a similar riveting process.
A third multi-stage die system or press 1362 may be used to align the pull ring and tab assembly with a corresponding crown body, cut the pull ring and tab from the tab sheet, attach the assembly to the crown using a rivet (either formed on the crown body or using a separate rivet), trim the assembled ring pull crown, and form the corrugated skirt. In accordance with one embodiment illustrated by
After the completed ring pull crown is separated from the remaining carrying web, the remaining unused crown body strip proceeds south along the conveyer until it is consumed by a scrap chopper 1355. The chopped scrap is deposited onto one or more scrap conveyers 1358, which transports the scrap into a scrap bin (not shown). Likewise, the leftover tinplate feed from the ring and tab coil is processed by a second scrap chopper 1359 located at the end of the pull ring and tab assembly process line. The scrap is carried by a second scrap conveyer 1360 to a scrap bin. In certain preferred embodiments, as shown in
By positioning the off-center location of the attachment portion 1520 towards the “rear” of the crown 1500, additional leverage is created for when the user pulls the pull ring 1510 towards the front of the crown 1500. Thus, additional leverage allows the user to more easily tear the score lines 1550a and 1550b during the opening process. Accordingly, the movement of the attachment location 1520 is not arbitrary, and is instead done so towards the rear of the crown 1500 in an effort to increase leverage during score line tearing. Additionally, the distance that the attachment location 1520 is moved off-center can be selected depending on the above of increased leverage desired. For example, if a thicker crown is employed, then more tearing leverage may be provided for easier opening. Of course, thickness of the crown 1500 need not be a consideration. Similarly, the number, length and alignment of the one or more of the rear score lines 1540 may also be selected depending on thickness of the crown 1500, among other considerations.
Also in this embodiment of the crown 1700 manufactured in accordance with the disclosed principles, a membrane 1760 may be included under the top surface of the crown 1700. In this embodiment, such a membrane 1760 may be included in place of the liner typically found in bottle caps. More specifically, this embodiment of the crown 1700 may be used on a medical vial or other similar container, and thus the membrane 1760 may be a pierceable membrane to be pierced by a syringe or other similar medical device. Also important in this embodiment is the non-fluted skirt 1760. Specifically, the skirt 1750 in this embodiment may be formed by the above-described techniques so that it may be crimped around the medical vial container. Thus, this embodiment of the crown 1700 manufactured as disclosed herein is unique in that the skirt is “inverted” inward, yet the crown 1700 may still be torn and removed from the container.
The illustrations of embodiments described herein are intended to provide a general understanding of the structure of various embodiments, and they are not intended to serve as a complete description of all the elements and features of apparatus and systems that might make use of the structures described herein. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. Other embodiments may be utilized and derived therefrom, such that structural, materials, and logical substitutions and changes may be made without departing from the scope of this disclosure. Figures are merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
Such embodiments of the inventive subject matter may be referred to herein, individually and/or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.
This application is a continuation of U.S. patent application Ser. No. 14/700,865, filed Apr. 30, 2015, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 61/986,521, filed Apr. 30, 2014, both of which are hereby incorporated by reference in their entireties for all purposes. In addition, the disclosures of U.S. Pat. Nos. 8,061,544; 8,276,773; 8,365,940; 8,608,006; and 8,944,264; and U.S. patent application Ser. Nos. 14/098,208; 14/244,571; and 14/605,704, all by the same inventor, are also hereby incorporated herein by reference for all purposes.
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| 3366086 | Fraze | Jan 1968 | A |
| 4760729 | Kaminski | Aug 1988 | A |
| RE33061 | Brown | Sep 1989 | E |
| 6105806 | Stasiuk | Aug 2000 | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20170368593 A1 | Dec 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61986521 | Apr 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14700865 | Apr 2015 | US |
| Child | 15698122 | US |
