Patent Application
20250083864
Not Applicable.
The present invention relates to pull tabs for beverage containers, and more particularly to a method of manufacturing pull tabs with elevated lift ends and associated tooling.
Pull tabs are critical components of containers like beverage cans, providing consumers with a means to open the container efficiently. Traditional pull tabs are generally flat and may require significant effort to actuate, potentially leading to a suboptimal user experience. Elevated lift-end pull tabs have been developed to address this issue by raising the lift portion of the tab for easier access. However, existing designs suffer from key limitations, particularly in their compatibility with commercial packaging systems and their inability to balance user ergonomics with manufacturability.
One significant drawback of current elevated lift-end pull tabs is their inability to achieve universal stacking compatibility. These designs often fail to align with industry-standard shadow bead geometries, resulting in stacking inefficiencies, increased shipping costs, and coating abrasion issues during transit. Current elevated pull tabs frequently have upward bends isolated within the lift portion, which can interfere with stacking in commercial packaging systems. These designs may prevent effective stacking on beverage container lids, particularly when additional structural features such as “shadow beads” (protrusions on the lid) are present. Moreover, isolated bends may not provide the optimal finger access desired for user convenience. The isolated placement of bends not only limits the lift portion's elevation but also reduces the available finger access area, compromising user convenience and increasing the perceived force required for actuation.
The manufacturing of conventional container lids, also known as ends or converted ends, involves combining two key aluminum components: the shell and the tab. Together, these components form a completed converted end, which is used to seal and open beverage containers or similar packages. The shell is the circular lid that covers the container, while the tab is the small lever that consumers lift to open the container. These two parts are assembled in a final process where the tab is securely riveted to the shell using an integrated rivet. The rivet, which is formed as part of the shell, provides a robust attachment point for the tab. This process has been refined over the years into what is now considered a modern conversion press. The conversion press is a specialized piece of equipment named for its ability to convert a plain shell into a fully functional converted end while simultaneously forming the pull tab in the same machine.
The shell starts as a coil of aluminum that is fed into a shell press. This shell press is the first step in the process, cutting out the blank shape of the shell and forming it into its precise dimensions in a single stroke. The completed shell is then passed to a separate machine where a sealant is applied inside the curled edge of the shell. This sealant ensures a tight and leak-proof seal when the shell is later seamed onto a filled can. Once the sealant is applied, the shells are transferred to the conversion press for final assembly.
The conversion press is the last step in creating converted ends before they are prepared for shipping. At its core, the conversion press uses hydraulically centered guide pistons and crankshaft-driven mechanism to precisely guide its moving components. This includes the slide, the upper part of the press that moves during operation, and the press bed, the stationary lower portion. These components provide the force and precision necessary for the various forming operations. The materials fed into the conversion press are shaped using dies, which are tools that form the shells and tabs. The conversion press is unique because it uses two separate dies for this purpose: the lane die and the tab die.
The lane die shapes the shell into its final functional form by adding key features, including the integrated rivet, which serves as the connection point for the tab, the score or frangible region, which is a thin, breakable section of the shell that opens when the tab is lifted, and the deboss panel, which counteracts compression forces commonly called oil canning that are created during scoring. The lane die also forms a shadow bead, a small protrusion designed to minimize compression forces around the score and ensure proper opening characteristics.
The tab die is a progressive die that forms the tab from a precisely cut aluminum strip. In the first step, unnecessary material is punched out and all necessary holes are added. Next, the tab blank is cut from the aluminum sheet while leaving carry strips intact. These carry strips secure the tab to the aluminum strip as it progresses through the tab die. Subsequent operations in the tab die, including wiping, bending, and coining, shape the tab into its final form. These operations are known in the art and would remain largely unchanged in this embodiment. The reform station, which is the final stage of the tab die and sets the tab's final thickness, and in some cases, adds the lift feature, creating the elevated end of the tab that consumers use to open the container. Once the tab is fully formed, it is transferred to the lane die, where it is riveted onto the shell to complete the assembly. The remaining material from the aluminum carrier sheet is chopped into smaller pieces for recycling. Afterward, the converted ends may receive promotional markings or lettering, and any sharp edges are smoothed out to ensure consumer safety. Finally, the converted ends are palletized and shipped to fillers, where they are seamed onto filled cans.
Converted ends are designed to stack vertically, with the curled edge of one end resting on the curl of the end below it. This configuration ensures stable, compact stacking and prevents contact between the product-facing side of one end and the consumer-facing side of the next. However, improper tab design or manufacturing issues can cause the tabs to interfere with stacking, creating instability and reducing shipping efficiency. This interference can lead to a spongy effect, where the stack compresses under force. For this reason, the height and position of the tab's lift end must be carefully controlled during the design process.
The manufacturing process for pull tabs, particularly those with elevated lift portions, presents several challenges. These include maintaining precise control over the formation of bends, ensuring consistent tab thickness, and achieving the desired elevation of the lift portion while preserving stacking compatibility. Prior art manufacturing methods often lack the precision required to produce tabs with dual-bend structures or tapered profiles that are critical for flexibility, stacking, and ergonomic functionality. Moreover, traditional tooling designs struggle to meet these requirements without excessive wear or costly retrofitting.
Additionally, the integration of features such as center bars for promotional material or tapered body shapes for improved stacking can further complicate the manufacturing process. Many prior designs fail to incorporate a tapering profile that optimizes material use while enabling the tab to stack seamlessly across varying lid configurations. Without such innovations, manufacturers face increased material costs and reduced production efficiency.
Furthermore, existing designs do not adequately address user-centric innovations, such as multi-finger engagement or expanded finger access windows. By elevating only portions of the lift-end, prior art tabs fail to provide the continuous surface necessary for optimal user ergonomics, contributing to consumer dissatisfaction and usability challenges.
As the beverage container industry continues to evolve, there remains a need for improved pull tab designs, manufacturing methods, and the associated tooling to enable their production, that can all address these challenges while meeting the demands of both consumers and manufacturers. The present invention introduces a novel pull tab design with dual-bend structures, a tapered profile, and a lift-end width that spans the entire tab body. These features, coupled with a specialized manufacturing process and tooling, address limitations in stacking compatibility, user ergonomics, and production efficiency, representing a significant advancement over the prior art.
A pull tab for opening a container with a frangible region on its lid is manufactured using a progressive die method. The method produces a tapered pull tab body with a nose portion and an elevated lift portion. The body's thickness at the nose portion ranges from 1 to 2 millimeters, with a preferred thickness of about 1.35 millimeters. This preferred thickness provides optimal opening properties for predominantly used container lids, balancing structural strength and material efficiency to ensure compatibility across various lid designs. The lift portion has a width between 11 and 16 millimeters, with 14 millimeters being optimal for balancing user comfort and manufacturability.
The width of the lift portion is a major innovation, spanning between both sides of the pull tab and elevating the entire lift portion above the container lid. This configuration creates a significantly larger finger access window, which improves user engagement by allowing more room for fingers to reach underneath the pull tab. The increased width also enables a multi-finger opening process, which reduces the strain on individual fingers by distributing the force across a broader surface area, significantly enhancing user comfort. Unlike prior art, where lift portions are typically rounded and provide limited space for actuation, the present design introduces a wider, more ergonomic surface for interaction.
The manufacturing process involves creating a dual-bend structure at optimally positioned locations along the body to elevate the lift portion. These bends are placed at precise distances from the nose along the longitudinal axis, ranging from 19.25 to 21.5 millimeters for the first bend and 20 to 23 millimeters for the second bend. The preferred embodiment positions the first bend at about 19.75 millimeters and the second bend at about 22 millimeters. The dual-bend structure ensures controlled and consistent elevation, creating a total height of approximately 1.5 millimeters, which is critical for maintaining stacking compatibility across all predominant lid designs
The lift portion thickness, defined as the vertical distance between the lift portion's top and bottom planes, is optimized to range from 0.5 to 1 millimeters, with 0.7 to 0.8 millimeters being preferred. This thinner profile compared to prior art increases finger access by creating more space underneath the tab for users to engage with it effectively. Additionally, the thinner lift portion improves manufacturability by minimizing material usage, enhancing the pull tab's sustainability and cost efficiency.
A key innovation is the tapering angle of the body, formed between a top and bottom planes, ranging from 0.2 to 5.6 degrees, with 2.1 degrees being the preferred embodiment. This taper allows the pull tab to align with varying shadow bead geometries on container lids, ensuring universal stackability while maintaining structural flexibility. By tapering the body from a thicker nose to a thinner lift portion, the invention enhances the pull tab's flexibility, making it easier for users to lift the tab while reducing the perceived force required for actuation. The tapering also supports material efficiency by reducing metal usage without compromising strength or performance.
The manufacturing process utilizes specialized tooling assemblies in a tab die of a conversion press, preferably within a forming station, which may include either a dedicated lift station or an existing reform station. These assemblies incorporate upper and lower tooling designed to form the tapering angles, bend locations, and dual-bend structure with high precision. These assemblies are designed to create precise bends and maintain tight tolerances, enabling consistent production of pull tabs with superior ergonomic benefits, stacking compatibility, and cost-effectiveness.
This method produces pull tabs that enhance user accessibility and opening comfort while maintaining compatibility with existing container lid designs and stacking requirements. By introducing a comprehensive solution to the limitations of prior art, the invention achieves superior ergonomics, manufacturability, and economic viability. The combination of dual bends, a tapered body, and specialized tooling represents a significant advancement in pull tab design and manufacturing.
The present invention addresses the drawbacks of the prior art by introducing a manufacturing method and the associated tooling to produce an elevated lift end pull tab. This innovative approach solves the challenges associated with elevated lift portions while maintaining stacking compatibility. By utilizing a dual-bend structure with precise positioning and angles of the bends, and a tapered body profile, the invention creates a pull tab that improves user accessibility without compromising structural integrity or manufacturability. The integration of precise tooling within a forming station ensures consistent quality and compatibility across a wide range of container lid designs. This comprehensive solution overcomes the limitations of previous manufacturing attempts at easy access pull tabs, offering the methods and tooling to produce a pull tab that is both functional and commercially advantageous. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
Illustrative embodiments of the invention are described below. The following explanation provides specific details for a thorough understanding of and enabling description for these embodiments. One skilled in the art will understand that the invention may be practiced without such details. In other instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list. When the word “each” is used to refer to an element that was previously introduced as being at least one in number, the word “each” does not necessarily imply a plurality of the elements, but can also mean a singular element.
In the context of the present invention, a forming station 300,305 refers to a station within a conversion press (not shown) specifically designed to shape the pull tab into a particular geometry. This includes producing the novel features of the pull tab such as upward bends, tapered structures, and precise angles that define the elevation and contour of the lift portion. The forming station may encompass one or more stations within a conversion press, including but not limited to the lift station 300 and the reform station 305, as well as any other station responsible for shaping the pull tab body to achieve the features described in this patent application.
Numeric references 300 and 305 collectively illustrate certain embodiments of the forming station, with reference 300 showing a lift station and reference 305 showing a reform station tooling assembly. These stations comprise upper and lower tooling assemblies configured to create the specific tapering profile, bend angles, and bend locations critical to the invention.
The process begins with a precisely formed aluminum strip being fed into a conversion press (not shown). This strip, prepared from the carrier sheet 70, serves as the base material for forming the pull tabs. The tab die uses punching and piercing tools to remove portions of the metal that are not needed for the finished tab. This step efficiently separates unusable material while preserving the attachment of the tab blank 60 to the carrier strips 75.
The outline of the tab blank 60 is formed, leaving the attachment points 65 intact through the carrier strips 75. These carrier strips ensure that the tab remains secured to the strip for precise movement through the tab die.
The tab blank undergoes further shaping through a series of progressive operations, including wiping, bending, coining, and paneling. These steps gradually form the tab into its final functional shape, ensuring both structural integrity and dimensional precision. The forming station 300,305 adds the lift feature to the pull tab, elevating the lift end and incorporating any upward bends or contours required for ergonomic functionality. This step is critical in defining the pull tab's usability and ensuring compatibility with the container lid's stacking and sealing requirements.
In some embodiments, at 300, a dedicated lift station further refines the lift-end geometry, ensuring the tab meets specific height and contour specifications. This additional refinement step optimizes the pull tab for both manufacturability and user accessibility.
Finally, the completed pull tab is transferred to the lane die (not shown), where it is riveted onto the container lid 40. This operation secures the pull tab to the lid using the integrated rivet 35. Any remaining scrap material is removed and conveyed for recycling, ensuring efficient material use.
This progressive die manufacturing method highlights the precision and efficiency of modern pull tab production, ensuring consistent quality and performance across high-speed manufacturing environments.
At a forming station 300,305, each tab blank 60 is formed into a pull tab 20 having a body 50 extending along a longitudinal axis L from a forward end 230 to a rearward end 240. Such a body 50 has a nose portion 120 at the forward end 230 configured to apply downward pressure on the frangible region 45 of the container lid 40.
A lift portion 110 is formed at the rearward end 240, disposed distally from the nose portion 120 and terminating at a distal end of the pull tab 20. A pair of opposing sides 143 extends from the nose portion 120 to the lift portion 110. The body 50 has a top surface 250 defining a top plane P1 and a bottom surface 260 defining a bottom plane P2.
Such a body 50 is tapered such that the thickness of the body 50 at the nose portion 120 between the top surface 250 and the bottom surface 260 is greater than the thickness at the lift portion 110, with a peak thickness PT located between the nose portion 120 and the first bend 170. This variable thickness profile is a key innovation that balances structural integrity, flexibility, stacking compatibility, and material efficiency.
The increased thickness at the nose portion 120 provides sufficient strength to apply force to the frangible region of the container lid during the opening process, while the peak thickness PT between the nose and the first bend 170 offers enhanced structural support at critical stress points. The taper from the peak thickness PT to the reduced thickness at the lift portion 110 improves flexibility, making it easier for users to engage with and manipulate the pull tab during container opening. The reduced thickness at the lift portion 110 further enhances the ergonomic usability of the pull tab by increasing the available space for under-tab finger access.
From a stacking perspective, the thinner lift portion 110 minimizes interference with shadow bead 48 geometries found on container lids (
The tapered profile also presents opportunities for material reduction, as the thinner lift portion 110 requires less metal compared to traditional designs. This variable thickness profile strategically redistributes material to provide additional strength where needed, while reducing material at the lift portion 110 to enhance flexibility and minimize weight. By incorporating this design, the pull tab achieves improved sustainability and cost-effectiveness without sacrificing performance. This efficient material usage makes the pull tab economically viable while maintaining the structural and functional requirements for high-speed manufacturing processes.
In some preferred embodiments, the top plane P1 and the bottom plane P2 may form a tapering angle α4 from the first bend 170 to the topmost point 290 of the tab at the peak thickness PT. This tapering angle α4, ranging between 0.20 degrees and 2.5 degrees, is a critical feature achieved at a reform station tooling assembly 305 of a progressive die conversion press. Tooling within the reform station assembly 305 is specifically configured to create this precise taper, ensuring compatibility with a wide variety of shadow bead 48 designs, including downward-protruding shadow beads 48 (
The range of 0.2 to 5.6 degrees has been identified as the minimum and maximum viable tapering angles that balance stacking requirements, manufacturability, and pull tab flexibility. Tooling within the reform station assembly 305 or lift station 300 is designed to precisely form these angles, ensuring consistent production of pull tabs with optimal performance. By maintaining this range, the manufacturing process can achieve compatibility with industry-standard lid geometries while supporting the structural requirements necessary for user actuation. Furthermore, this design minimizes wear on reform station 305 or lift station 300 tooling by avoiding overly sharp angles, which can lead to increased maintenance and costly production downtime.
A narrower range of tapering angles, between 1.5 and 2.5 degrees, has been shown to provide the best balance between stacking compatibility and manufacturability. This range is preferred by manufacturers as it enables consistent tooling performance and preventing fracturing of the tab stock, while delivering pull tabs that meet user expectations for both strength and flexibility. For lids with predominant shadow bead 48 geometries, this narrower range allows the pull tab to stack efficiently while optimizing material usage by providing a thinner, more flexible body without compromising structural reliability.
An optimal tapering angle α4 of approximately 2.1 degrees has been identified as the preferred embodiment for universal compatibility across commercial lid designs. This specific angle is achieved using reform station tooling that precisely controls the taper during the manufacturing process, ensuring a balance between stacking viability, material efficiency, and ergonomic usability. The 2.1 degree angle provides sufficient clearance for shadow bead 48 geometries, enabling pull tabs to stack seamlessly on a variety of container lids while maintaining durability and ease of use.
Additionally, a lift angle α5 (
A rivet island aperture 210 is formed in the body 50 between the opposing sides 143 proximate the nose portion 120 (
In a particular embodiment, the carrier sheet 70 and pull tabs 20 are moved to either a lift station 300 or a reform station tooling assembly 305 within a conversion press manufacturing system. At the selected station, the pull tab 20 undergoes a controlled bending process to elevate the lift portion 110 relative to the top plane P1 of the pull tab 20. This elevation is achieved by forming at least one bend 170 in the body 50 between the nose portion 120 and the lift portion 110. The tooling within the lift station 300 or the reform station 305 is specifically configured to produce these bends with high precision, ensuring that the resulting geometry enhances user interaction while maintaining compatibility with varying shadow bead 48 geometries.
The carrier sheet 70 and pull tabs 20 are then moved to a cutting station (not shown). At the cutting station (not shown), the carrier strips 75 are severed from the one or more attachment points 65, releasing each pull tab 20 from the carrier sheet 70. This sequential process maintains the dimensional tolerances required for reliable stacking and user functionality.
The step of bending the pull tab 20 at the forming station 300,305 may comprise forming a first bend 170 in the body 50 between the nose portion 120 and the lift portion 110, and forming a second bend 175 in the body 50 between the rearward end 240 and the first bend 170. For simplicity, the first bend 170 is considered one bend even if it is opposite the finger hole 150, which technically could be considered two separate bends 170. Similarly, the second bend 175 is considered one bend even if it technically forms two opposing second bends 175, each on opposing sides of the finger hole 150. This dual-bend structure is integral to the proposed invention, as it defines the elevation of the lift portion 110 above the pull tab's top plane P1. The lift portion 110 is disposed between the rearward end 240 and the second bend 175, while an intermediate portion 270 of the body 50 is defined between the first bend 170 and the second bend 175.
The tooling in both the forming station 300,305 is designed to precisely control the formation of the first and second bends, enabling consistent production in a high-speed conversion press environment. The dual-bend structure provides several key advantages. First, the controlled formation of the bends optimizes the angles and height of the lift portion 110, ensuring that the total elevation aligns with stacking requirements for container lids with varying shadow bead 48 geometries. This precision prevents interference with shadow beads 48, avoiding issues such as coating abrasion or sponginess during stacking. Second, the dual bends enhance user ergonomics by creating a broader and more accessible under-tab finger access area. The strategic positioning of these bends ensures that the elevation is distributed evenly, improving manufacturability, and reducing the likelihood of fracturing or excessive tooling wear. Finally, the dual-bend process allows for the production of pull tabs with consistent dimensions, making the proposed invention highly compatible with industry-standard container lid configurations.
The step of bending the pull tab 20 at the forming station 300,305 may further comprise positioning the first bend 170 between 19.25 millimeters and 21.5 millimeters along the longitudinal axis L from the forward end 230 and forming the first bend 170 at an angle α2 of between 10 degrees and 45 degrees with the top plane P1. This defined range ensures precise positioning and angling of the first bend to enhance stacking compatibility and manufacturability. A first bend positioned closer to the nose than 19.25 millimeters risks interference with shadow bead 48 geometries, leading to stacking misalignment or coating abrasion. Conversely, positioning the first bend beyond 21.5 millimeters reduces under-tab finger access, diminishing the ergonomic benefits of the design.
The angle α2, ranging from 10 to 45 degrees, is critical for achieving a controlled elevation of the lift portion 110. Angles below 10 degrees may fail to produce sufficient lift for ergonomic usability and stacking compatibility. Angles exceeding 45 degrees risk fracturing the tab stock during high-speed manufacturing processes, leading to production inefficiencies and increased tooling wear. The preferred embodiment positions the first bend at approximately 19.75 millimeters along the longitudinal axis L, with an angle α2 of about 19 degrees. This positioning and angle have been determined through extensive testing to provide the optimal balance of manufacturability, ergonomic usability, and structural integrity.
The second bend 175 may be positioned between 20 millimeters and 23 millimeters along the longitudinal axis L from the forward end 230, and formed at an angle α3 of between 10 degrees and 45 degrees with the lift portion top plane P4, wherein the lift portion top plane P4 is substantially parallel to the bottom plane P2. The range for the second bend ensures that the total height H1 of the pull tab 20 from the bottom plane P2 to the lift portion top plane P4 aligns with the 1.5 millimeter height required for stacking compatibility across varying shadow bead 48 geometries. The second bend 175 positioned closer than 20 millimeters risks creating excessively sharp angles relative to the first bend, leading to material stress and potential fracturing during manufacturing. Positioning the second bend further than 23 millimeters reduces the elevation of the lift portion, limiting its ergonomic effectiveness and compatibility with shadow bead 48 geometries.
The angle α3, similarly ranging from 10 to 45 degrees, complements the first bend by creating a gradual and controlled elevation of the lift portion 110. This angle range prevents tooling wear and ensures consistency in manufacturing tolerances. The preferred embodiment positions the second bend at approximately 22 millimeters along the longitudinal axis L, with an angle α3 of about 19 degrees. This configuration optimizes the alignment of the lift portion with the shadow bead 48 geometries while ensuring sufficient under-tab finger access and compatibility with high-speed conversion press systems.
The step of bending the pull tab 20 at the forming station 300,305 may further comprise a dual bend structure, with a first bend 170 about 19.75 millimeters from the forward end 230, positioning the second bend 175 about 22 millimeters from the forward end 230, and forming the first and second bends 170, 175 at angles α2, α3 of about 19 degrees each. This specific embodiment defines the preferred distances and angles for universal stacking compatibility and ergonomic usability. The parallel alignment of the lift portion top plane P4 with the bottom plane P2 ensures a compact design, preventing accidental openings during shipping or handling. Furthermore, this configuration facilitates precise tooling operations, allowing the pull tab to maintain consistent dimensions during high-speed production while optimizing manufacturability and functionality.
The step of bending the pull tab 20 at the lift station 300 or reform station tooling assembly 305 may further comprise positioning the first bend 170 between 19.25 millimeters and 22 millimeters along the longitudinal axis L from the forward end 230, and forming the first bend 170 at an angle α2 of between 10 degrees and 45 degrees with the top plane P1. The second bend 175 may be positioned between 20 millimeters and 23 millimeters along the longitudinal axis L from the forward end 230, and formed at an angle α3 of between 10 degrees and 45 degrees with the lift portion top plane P4, wherein the lift portion top plane P4 is substantially parallel to the bottom plane P2.
The step of forming each tab blank 60 into a pull tab 20 may further comprise forming the body 50 such that the top plane P1 and the bottom plane P2 form an angle α1 of between 2 degrees and 10 degrees from the nose portion 120 to a first bend 170, resulting in the tapering of the body 50. This tapering angle α1 is critical to achieving a controlled and gradual reduction in the body thickness, which serves multiple purposes. First, the taper enhances the flexibility of the pull tab 20, particularly at the lift portion 110, by creating a progressive transition in material thickness. This flexibility improves user actuation during container opening while reducing the perceived opening force.
From a manufacturing perspective, the angle α1 is carefully controlled to prevent fracturing of the tab stock material during high-speed forming operations. Angles below 2 degrees may result in an insufficient taper, reducing the ergonomic benefits of the pull tab by limiting its flexibility and under-tab finger access. Conversely, angles exceeding 10 degrees increase the likelihood of material stress during the forming process, leading to potential fracturing or deformation in the nose portion 120. By maintaining the angle α1 within this range, the tooling in the reform or lift station ensures consistent tolerances and minimizes wear, even in high-speed production environments.
The narrower range of 4 to 5 degrees, and more specifically about 4.34 degrees, represents the preferred embodiment for balancing material flexibility, stacking compatibility, and manufacturability. This specific tapering angle aligns with shadow bead geometries to prevent interference during stacking, ensuring that the pull tab nests properly within standard container lid configurations. The gradual taper also minimizes tooling wear by distributing the forming forces evenly, reducing the likelihood of localized stress concentrations that could damage the tooling or the tab stock material.
The step of forming each tab blank 60 into a pull tab 20 may further comprise forming the thickness T1 at the nose portion 120 to be between 1 millimeter and 2 millimeters. This thickness range is essential for maintaining the structural integrity of the nose portion 120, which interacts directly with the frangible region of the container lid during the opening process. A thickness T1 below 1 millimeter may compromise the strength of the nose portion, increasing the risk of fracturing during actuation or failing to generate sufficient force to rupture the frangible region. On the other hand, a thickness greater than 2 millimeters would add unnecessary material, increasing production costs and reducing the economic viability of the design.
The preferred thickness T1 of about 1.35 millimeters achieves an optimal balance between strength and material efficiency. This thickness ensures that the nose portion 120 is robust enough to handle the required opening forces without deforming, while also minimizing material usage for improved sustainability. The tooling in the reform or lift station is designed to consistently achieve this thickness within high-speed production tolerances, ensuring reliable performance across all produced pull tabs.
The lift portion 110 may have a width W1 between each opposing side 143 of between 11 millimeters and 16 millimeters. This width range is achieved through precisely configured upper and lower tooling assemblies in either a lift station 300 or a reform station 305 within a conversion press manufacturing system. The tooling assemblies are specifically designed to shape the lift portion 110 with tight tolerances, ensuring that the defined range of 11 to 16 millimeters is consistently produced across high-speed manufacturing processes. A width W1 closer to 11 millimeters is ideal for smaller-diameter lids 40, where a compact design may be necessary to integrate effectively with existing systems. Conversely, a width W1 closer to 16 millimeters is advantageous for larger-diameter lids 40, offering a broader surface for finger contact and facilitating multi-finger opening.
The upper and lower tooling assemblies of a lift station 300 are designed with complementary forming surfaces that work together to shape the lift portion 110 precisely. The upper tooling assembly 330 applies controlled pressure through a spring loaded upper pressure pad 340 against the lower bender die insert 380, while the lower tooling assembly 360 incorporates a bender die insert 380 to ensure the lift portion achieves the desired thickness and height. These assemblies are meticulously engineered to create smooth, continuous bends along the sides of the pull tab, eliminating inconsistencies that could affect functionality or stacking compatibility.
The width W1 of the lift portion 110 may be about 14 millimeters. This specific width represents the preferred embodiment, balancing user comfort, ergonomic usability, and manufacturability. The 14 millimeter width W1 is formed with precision by the upper and lower tooling assemblies in the lift station 300 or reform station 305. These assemblies are configured to maintain consistent forming pressures, ensuring that the lift portion meets the required tolerances for stacking compatibility, finger access, and ergonomic interaction.
This precise shaping of the lift portion ensures that consumers experience reduced perceived force when opening containers, as the broader surface allows for multi-finger engagement and even force distribution. Additionally, the precise forming process minimizes material waste, enhancing cost-effectiveness and sustainability in production. The coordinated action of the upper and lower tooling assemblies ensures the lift portion 110 is optimally shaped for both functional and economic performance, making the present invention a significant advancement over prior art.
The step of bending the pull tab 20 may further comprise forming the lift portion 110 to have a vertical distance from the lift portion top plane P4 to a lift portion bottom plane P3 of between 0.5 millimeters and 1 millimeter. Such a vertical distance from the lift portion top plane P4 to the lift portion bottom plane P3 may be formed to be between 0.7 millimeters and 0.8 millimeters.
Thicknesses below 0.5 millimeters pose a significant risk of fracturing during high-speed production, as the thinner material may not possess the necessary resilience to withstand repeated stamping and handling. Conversely, a lift portion thickness greater than 1 millimeter provides diminishing returns in terms of finger access and usability, as it reduces the available space for users to reach underneath the pull tab 20 while adding unnecessary material. This range ensures that the lift portion 110 is sufficiently durable for handling and consistent user interaction without compromising manufacturability or material efficiency.
The vertical distance from the lift portion top plane P4 to the lift portion bottom plane P3 may be formed to be between 0.7 millimeters and 0.8 millimeters. This preferred range balances ergonomic usability with structural reliability, providing sufficient under-tab finger access for user engagement while maintaining the necessary strength to resist deformation. At this thickness, the pull tab 20 offers a comfortable tactile feel, enhancing the user experience by reducing perceived opening force through improved finger surface area contact.
From a manufacturing perspective, the 0.7 to 0.8 millimeter range minimizes the risk of fracturing during the forming process while allowing for precise control of material deformation. Tooling assemblies within the forming station 300,305 are specifically designed to form this thickness range consistently, ensuring the lift portion 110 remains uniform across high-speed production cycles. By achieving this optimal thickness, the tooling minimizes material waste, contributing to the economic and sustainable production of pull tabs 20.
The slightly thinner profiles within this range provide increased finger access by maximizing the space between the pull tab 20 and the can lid surface. This improvement in accessibility enhances user satisfaction by making it easier to engage with the tab during container opening. Additionally, the thinner profiles improve material economy, reducing overall metal usage while maintaining sufficient structural integrity to prevent deformation during handling. The tooling system's ability to consistently produce the lift portion 110 within this range highlights the manufacturing innovation of the proposed invention, setting it apart from conventional elevated lift-in tabs currently on the market.
The step of bending the pull tab 20 may further comprise elevating the lift portion 110 above the top plane P1 of the pull tab 20 and extending the lift portion 110 between each opposing side 143, thereby providing a continuous elevated surface for user interaction. This elevation is achieved through precisely designed upper and lower tooling assemblies within a forming station 300,305 in a conversion press manufacturing system. The tooling is configured to create the upward bends 170, 175 on the sides 143 of the pull tab 20, ensuring consistent formation of the lift portion 110 with the required dimensions and tolerances to support manufacturability and usability.
This novel design redefines user interaction with pull tabs 20 by elevating the entire lift portion 110 above the top plane P1 of the pull tab 20. Unlike prior art, which isolates bends within the lift portion itself, this design creates a continuous elevated surface that extends uniformly across the width of the pull tab. Traditional easy-access pull tabs typically feature a small arc or square-back shape in the lift portion, concentrating user interaction in a limited area and restricting the under-tab finger access window. These prior designs increase pressure on the finger due to limited surface area contact, reducing ergonomic effectiveness.
By placing upward bends 170, 175 on the sides 143 of the pull tab 20 and elevating the entire lift portion 110, the present invention creates a significantly wider and more accessible finger access window. This window extends across the full width of the pull tab 20, enabling multi-finger interaction and distributing pressure across a larger area. This design reduces the strain felt by consumers during the opening process and enhances comfort and efficiency. The continuous elevation ensures that the geometry of the lift portion 110 is less rounded compared to prior art, providing a larger, more ergonomic surface for finger contact, and enabling easier container opening.
The upward bends 170, 175 located on the sides 143 of the pull tab 20 also optimize manufacturability. Tooling assemblies within the forming station 300,305 are configured to produce these bends with high precision, eliminating interference with carrier strips commonly used in the ear carry method. Unlike prior art designs, which isolate bends in the lift portion and often disrupt carrier strip placement during manufacturing, the present invention allows for seamless integration into existing conversion press systems. The dual bends 170, 175, combined with the elevated lift portion 110, enable manufacturers to retrofit existing systems with minimal cost and effort compared to retrofitting for prior art designs.
This design also achieves the maximum allowable finger access within the constraints of current lid designs while maintaining compatibility with standard shadow bead geometries. The tooling ensures consistent elevation and alignment, preventing issues such as coating abrasion or stacking misalignment that commonly affect easy-access pull tabs on the market. Traditional designs often leave portions of the lift portion flat and flush against the container lid, limiting both under-tab finger access and surface area interaction. By elevating the entire lift portion 110 uniformly across the width of the pull tab 20, the present invention resolves these limitations, creating a continuous elevated surface for user interaction and dramatically improving under-tab finger access.
The precision of the upper and lower tooling assemblies ensures the lift portion 110 achieves the required elevation and width while maintaining compatibility with high-speed manufacturing processes. This tooling innovation enables consistent production of pull tabs 20 with superior ergonomic benefits, stacking compatibility, and cost-effectiveness, making the present invention a significant advancement over prior art.
A lower tooling assembly 360 includes the bender die 405, a spring-loaded lower pressure pad 370, and a lower bender die insert 380 configured to cooperate with the upper bender punch insert 322 to form the first bend 170 and the second bend 175 in the pull tab blank 60. The lower bender pressure pad spring pin 425 applies spring pressure to the lower bender pressure pad 370. The lower bender die spacer 395 below the bender die insert 380 facilitates setting the lower bender die stack height for precise bend height control. The lower bender die 405 holds the lower assembly together and fastens the lower assembly to the rest of the lower tab die assembly (not pictured).
In a particular embodiment of the reform station tooling assembly 305, it may include an upper reform punch 410 and lower reform die 420, which collectively act as the upper and lower assemblies within a reform station to form the pull tabs novel features as described herein.
While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the invention.
The above detailed description of the embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above or to the particular field of usage mentioned in this disclosure. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. Also, the teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
All of the above patents and applications and other references, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the invention.
Changes can be made to the invention in light of the above “Detailed Description.” While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Therefore, implementation details may vary considerably while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated.
While certain aspects of the invention are presented below in certain claim forms, the inventor contemplates the various aspects of the invention in any number of claim forms. Accordingly, the inventor reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention.
The present invention is a Continuation-in-Part of US Utility Patent Application 18/951,007, filed on Nov. 18, 2024, which itself is a Continuation-in-Part of U.S. Utility patent application Ser. No. 18/733,452, filed on Jun. 4, 2024, which itself is a Continuation-in-Part of U.S. Utility patent application Ser. No. 18/236,703, filed on Aug. 22, 2023, which claims the benefit of U.S. Provisional Patent Application 63/478,185, filed on Jan. 2, 2023, as well as U.S. Provisional Patent Application 63/507,934, filed on Jun. 13, 2023, as well as U.S. Provisional Patent Application 63/507,938, filed on Jun. 13, 2023. U.S. patent application Ser. No. 18/951,007 filed on Nov. 18, 2024, is further a Continuation-in-Part of U.S. Utility patent application Ser. No. 18/829,257 filed on Sep. 9, 2024, which itself claims the benefit of U.S. Provisional Patent Application 63/537,633, filed on Sep. 11, 2023. All of these applications are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63537633 | Sep 2023 | US | |
| 63478185 | Jan 2023 | US | |
| 63507934 | Jun 2023 | US | |
| 63507938 | Jun 2023 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18951007 | Nov 2024 | US |
| Child | 18960686 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18829257 | Sep 2024 | US |
| Child | 18951007 | US | |
| Parent | 18733452 | Jun 2024 | US |
| Child | 18951007 | US | |
| Parent | 18236703 | Aug 2023 | US |
| Child | 18733452 | US |
