Patent Application
20120273492
1. Field of the Invention
The invention generally relates to closures and to closure opening arrangements, such as opening devices. More specifically, the invention relates to a closure having a frangible member about a line or point of weakness, where the member is nonremovable, and where a gripping means, such as a pull tab or other opener, is attached to or integral with the member.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Pressurized beverage containers include self-opening devices on the top end panel. A typical self-opening device consists of an opening area of the end panel largely circumscribed by a frangible line, leaving a minor, non-circumscribed portion of the opening area connected directly to the remainder of the end panel. The non-circumscribed connection is referred to as the hinge. When sharp pressure is applied to the circumscribed opening area, the frangible line fractures, leaving the opening area attached to the end panel by only the hinge. The opening area can then be bent on the hinge to open the container, creating a resultant opening large enough for drinking or pouring the contents. The opening area is sometimes known as a press tab. Variations in the size of the opening area are considerable. Some containers, usually food cans, may have the majority of the end panel circumscribed by a frangible line near the perimeter of the end panel, with no hinge, such that substantially the entire end of the container is removable by tearing or fracturing the frangible line.
A self-opening device further provides a pivot lever that is attached to the end panel by a rivet that also serves as a fulcrum. The pivot level is positioned above the top of the end panel so that when a first end is raised, the opposite end presses against the opening area and fractures the frangible line. Further raising the first end causes the second, opposite end to rock downward on the fulcrum and thereby depress the opening area on the hinge, creating a large access opening in the end panel. The pivot lever is variously known as a stay-on tab or pull tab. Variations of the pivot lever are used on food cans to start a fracture of the frangible line, after which lifting the pivot lever also pulls up the removable portion of the end panel and tears the remainder of the frangible line. Self-opening devices are desirable because the stay-on tab remains together with a larger portion of the container, whether that portion is the remaining entirety of the container or merely a large fraction of the torn-away lid. In either event, the relatively small stay-on tab tends to be properly disposed of, in combination with its attached portion of the container or end panel.
A problem in the art is that the stay-on tab can be difficult to lift. Gaining finger access under the first end of the stay-on tab is an initial challenge. The tab is riveted to the end panel, which creates a stiff, close mounting. Such a close mounting is needed and desired because the containers are designed to stack, requiring that the base of an upper container can nest in the top of a lower container. A further complicating feature is that the stay-on tab must have sufficient beam strength such that it is not easily bent, so that it can fracture the frangible line when lifted. Thus, the stay-on tab is stiff, strong, and closely positioned to the top end panel, creating a problem for many persons to access and lift the stay-on tab to open the container.
Various tab and container end designs have attempted to solve this problem, but the problem persists. As examples, U.S. Patent Application Publication 2006/0196875 to Cherian suggests a tab with lifting end bent up, with a recess in the end panel below the lifting end of the stay-on tab, and with ramped spacers for holding the lifting end of the tab at a spacing from the end panel. U.S. Pat. No. 6,138,856 to Ghim et al. shows an end panel configured to define a recess under the lifting end of the stay-on tab. These suggested solutions require expensive modifications to manufacturing tooling, and the operation of the resulting opening devices is not always clear to the consumer.
It would be desirable to provide an end closure with a stay-on tab that could be readily accessed and lifted, in a design that did not interfere with the stackability of the containers.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise the following.
Against the described background, it is therefore a general object of the invention to provide improved finger engagement with the lever end of a stay-on tab.
The invention is a can end structure having an opening tab or opening ring that is arranged for improved access by the user's fingertip. As with conventional opening tab structure, the tab is riveted to the end panel of the can, with a nose portion of a first end extending distally beyond the rivet to serve as an opening lever. A lifting lever extends proximally from the rivet. The user must lift the lifting lever at the second, lifting end of the tab to tilt the tab across the rivet as a fulcrum. As the user raises the lifting lever, the extending nose of the first end is forced down against an opening panel, separating a parting line at the margins of the panel and pushing the panel down. The lifting end of the tab is contoured in a simple or compound curve at the lifting end, creating a cavern-like fingertip entry gap at the lifting end.
The improvement is the creation of extra space between the end panel and the lifting end of the tab. Various modifications achieve this result. In one modification, the lifting end of the tab is contoured with an upward curve near the center of the lifting end, creating the cavern-like fingertip entry gap at the lifting end. In a second modification, the typical gripping portion of the tab can be reduced to a concavity so that it is configured as U-shaped. The fingertip is inserted into the open side of the U-shaped lifting portion. In a third modification, elevation walls and spacers lift and support the lifting end of the tab at a suitable separation from the end panel, creating a finger entry gap at the second end. The spacers can be upraised from the end panel or depend from the bottom of the tab.
According to the invention, a longitudinally disposed stay-on opening tab is adapted for mounting on a container having an opening panel at least partially defined by a parting line. A distal end of the tab is a container opening nose. A proximal end of the tab is a lifting lever. A fastener attachment structure is intermediate the container opening nose and lifting lever. The lifting lever defines a proximal end edge that is configured as a concavity and sized to at least partially receive a user's fingertip.
According to another aspect of the invention, a container lid is formed of a lid body with a parting line that at least partially defines an openable panel in the lid body. A fastener is positioned on the lid body in predefined proximity to the openable panel for attaching a stay-on tab at a suitable location for selective operation to separate the parting line. A stay-on opening tab is formed of a container opening nose at a distal end of the tab, a lifting lever at a proximal end of the tab; and a fastener attachment structure intermediate the container opening nose end and lifting lever. The lifting lever defines a proximal end edge configured as a concavity and sized to at least partially receive a user's fingertip.
According to still another aspect of the invention, a container is formed of a container wall with a parting line that at least partially defines an openable panel in the container wall. A fastener is positioned on the container wall in predefined proximity to the openable panel and attaches a stay-on tab in a suitable location for selective operation to separate the parting line. The stay-on tab is formed of a distal end portion that lies generally along a first plane near the container wall. A proximal end portion of the tab defines a proximal end edge that is configured as a concavity and is sized to receive at least a portion of a user's fingertip therein. A fastener attachment structure is engaged with the fastener and attaches the tab to the container wall in predefined proximity to the openable panel for selectively operation to separate the parting line.
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings:
The invention is an improved, ergonomic opening tab for a container. In a further aspect, the invention is a container lid having an improved, ergonomic, stay-on opening tab positioned to actuate an opening panel in the lid. In another aspect, the invention is a container having an improved, ergonomic, stay-on opening tab positioned to actuate an opening panel at a preselected location on the container.
The tab is configured to provide two major tab portions. Optionally, the two tab portions are generally disposed along separate planes, at different elevations, or on different levels with an offset wall interconnecting the two tab portions. The two major tab portions are, first, an opener or pressing lever at a first level and, second, a lifter or gripping portion that is optionally at least partially on a second level, offset above the first portion at the first level. The first level is approximately juxtaposed to an underlying surface of the container body or container lid, when the tab is attached to the container. The second level, where optionally employed, is offset to a greater distance from the underlying surface of the container body or container lid, when the tab is attached to the container.
The first tab portion extends from a distal end to a mounting structure such as an opening for receiving a rivet or other fastener attaching the tab to a container. The second tab portion extends from the mounting point to a proximal end for gripping engagement by a user to employ the tab for opening the container. At least a portion of the gripping means is positioned at an upward or more distant offset from the level of the opening lever and from an underlying opening panel of a container surface and is contoured with a concave reception face for receiving a user's fingertip. This invention is an improvement in openable can ends for food and beverage cans that employ stay-on tabs or pull tabs for separating the opening portion from the remainder of a container lid.
The container itself and the lid, in particular, typically are formed from sheet material such as sheet metal. Such sheet material enables an opening panel to be defined by a frangible or separable parting line at a selected location on the container, most commonly on the container lid. The parting line can be established by scoring, coining, or any other process. The parting line is configured in a desired contour at a desired location, whether on the container lid, container bottom, container sidewall, or elsewhere. The invention is applied to such containers, where most typically the parting line is established on the lid or closure. For purposes of description and not as a limitation, the invention will be described as being applied to the lid of a container, which is a typical commercial application of a stay-on opening tab.
Thus, most typically the lid or closure, or an openable portion of the lid or closure, is constructed to be ruptured, fractured, or cut away in order to gain access to the receptacle contents. The rupture, fracture, or cut is located at a predetermined line or point of weakness. The stay-on tab or pull tab includes a means for the user to grip the stay-on tab or pull tab. The gripping means is integral with or attached to the stay-on tab. The stay-on tab is connected to the container in such a way that the tab can tilt on a fulcrum to separate the parting line and thereby open the container. Depending on the design of the container, the tab can be tilted beyond the necessary degree to separate the parting line. This additional tilting of the tab may be effective to depress the opening panel into the container to improve access at the opening, or with certain styles of tabs and parting lines, the gripping portion may be pulled upwardly to rip the opening panel away from the remainder of the container.
For convenience of description, the term, “parting line” will be used throughout this description to describe the predetermined line of weakness, regardless of how the line of weakness was established. The term, “separate” will be used to describe the process of causing the parting line to open, regardless of what technique is used to achieve or enlarge the opening. The new tab will be described in two primary embodiments. One is similar to commercial tabs found on food cans, and the second is similar to commercial tabs found on beverage cans. While the two embodiments will be described as having certain differences in size and details of construction, the inventive features are applied to both. Therefore, the description of inventive features for either embodiment is equally applicable to the other unless specifically stated to be otherwise. The same numbering will be used to identify the same elements in either style of tab.
Tab 10 is formed in one piece, although it would be possible to employ multiple component pieces joined together as required for strength and functionality. The tab 10 can be formed of metal, such as aluminum or steel. Areas of the tab may be cut away as found practical to reduce the amount of metal in the tab structure. Portions of the tab may be formed of multiple layers of metal, and edges may be turned over or under to provide beam strength as required and to eliminate exposure to sharp edges.
The tab 10 is designed to be mounted on a container. For this purpose, the tab includes a fastener attachment structure 12. An efficient mounting method is by riveting the tab to the container at a preselected location such that the tab will be properly located to open a predefined opening panel. The rivet 58 is integral with the container, most commonly with the lid 50 of the container. Tab 10 may provide a fastener attachment structure that is specifically for receiving the rivet 58. A suitable structure is a hole 12. An integral rivet 58 can be formed in the container lid in a preliminary cylindrical shape that can be inserted through the hole 12. Once the rivet has been inserted, the portion extending beyond the tab can be flattened to create a rivet 58 with head that is larger than hole 12. The rivet head holds a local portion 18 of the tab in juxtaposed position against the underlying surface of the container. At least the local portion 18 of tab 10 under the rivet head remains in such a juxtaposed position.
Portions of tab 10 provide at least two functions that are distinctly identifiable, although interrelated. It is useful to refer to separate physical sub-portions of the tab 10 that chiefly perform each function. The division of the tab into such physical sub-portions is inexact because the tab is typically a unitary structure and has no sharp dividing line between sections performing each function. Therefore, the sub-portions are identified primarily for purposes of description, with the understanding that the described functions may not be entirely localized as attributed in the description.
With the above understanding in mind, the fastener attachment structure 12 is selected for purposes of description as a division point or middle area between two functionally differentiated sub-portions at opposite longitudinal positions with respect to structure 12. In the view of
The rivet or other fastener at hole 12 serves as the fulcrum. When the right longitudinal end of tab 10, as viewed in
When the right end of tab 10 is lifted, the left end of tab 10 tends to pivot down from hinge 20 of sheet material at the non-severed, left end of hinge ear 18. Hinge 20 bends more readily than the rivet, such that nose 14 drops from hinge 20, efficiently transferring the lifting force applied to the right of the hole 12 to the dropping nose located at the left of hole 12 and the rivet.
Referring again to the view of
Consumers face a difficulty in operating some stay-on tabs because it is difficult to raise the lifting lever of the known commercial tabs. This difficulty falls into two interrelated objections. One objection is that the commercial tab is inherently difficult to lift at a lifting lever simply because the opening panel of the commercial container requires considerable force to separate the parting line. The use of a longer lifting lever 22 would provide a solution, but the length of lifting lever 22 is limited by the size of the container and by the need to maintain enough space for finger access to the tail of the lifting lever. Some consumers fix the objection by using a pry bar such as a knife or screwdriver to lift the lifting lever 22.
The second objection is that the commercial tab is mounted too close to the underlying surface of the container, making it difficult and sometimes painful to initiate fingertip access under the lifting lever. Some consumers fix this objection by the same expedient of employing a pry bar that can be forced under the lifting lever to raise it.
Tab 10 resolves these problems by establishing a user-friendly, ergonomic, proximal edge 24 on lifting lever 22. According to the view of
A user typically employs his thumb or index finger to open commercial stay-on tabs. Of course, the width of a human thumb or index fingertip can vary among different individuals. Expected variation occurs between males and females, persons of different ages, and persons of different sizes and weights. As a guideline for determining a suitable width to enable concave edge 24 to achieve an ergonomic result, a typical size for an index fingertip is about five-eighths of an inch wide, while the width of a thumb is about seven-eighths of an inch wide. These estimates of typical size are confirmed by numerous sources, both ancient and modern. Ancient measurements include a unit known as Etzba, or a thumb breadth, which has been estimated to be from 2-2.4 cm, or 0.79-0.94 inches. Some modern reports suggest that the width of a human male finger is about 2 cm, or 0.79 inches. A biomechanical study suggests that a human fingertip width is 16-20 mm, or 0.63-0.79 inches. These size estimations are useful in meaningfully referring to the size of a human finger and in formulating a contour for edge 24.
Considering variations among people's digits and considering that in many or most examples, the concave recess will receive a limited portion of the index fingertip, a minimum desired concavity is thought to be in a range from about three-eighths inch to about one-half inch. This measurement can be regarded as the width 26 across the mouth of the recess created by concave edge 24. Larger or wider fingertips or thumbs are accommodated by partial receipt into the cavity defined by edge 24. The depth of the cavity can be measured at a normal line or longitudinal axis from mouth opening 26 to the center point of edge 24, shown in
As an additional aid to users who employ a combination of thumb and index finger to open some stay-on tabs, the lifting lever 22 defines a counter-engagement hole 32 for receiving a user's finger. This finger hole 32 may be similar in width to recess 24, where allowed by the size of the tab.
The second, elevated level of tab 10 includes edge 24 and will be described as being the higher or upper plane because, in application, the level including edge 24 is spaced above the underlying container wall in the typical orientations shown in
Where the tab employs a finger hole 32, a transverse bridge 36 is present between the finger hole 32 and edge 24. This transverse bridge 36 is the primary vertically arched structure of proximal end 22. A secondary transverse bridge 38 may be present between the finger hole 32 and fastener attachment hole 12. The secondary bridge may be slightly vertically arched as an initiating structure to the greater vertical arch of bridge 36. The bridges 36, 38 serve a purpose similar to elevation walls 34 by creating an upward offset over a central portion of edge 24, thereby creating a gap between the central portion of edge 24 and the underlying container surface. Elevation walls 34 are not necessary in the embodiment of
The vertical, longitudinal arch along proximal end 22 stiffens the proximal end to better transmit lifting forces to the distal end for operating the opener. The vertical aspect of the arch also establishes an enlarged gap under the center of edge 24 for improved finger access. The tab of
Hinge ear 18 is below the center of the arch, approximately at the base level. When the hinge ear is riveted to a container lid, it will be held against the container lid at the rivet location and height, which sometimes can be slightly above or below the base level of the tab, depending upon the contours of the container lid. Hinge 20 extends between hinge ear 18 and the upper, arched portion of the tab near nose 14. Therefore, hinge 20 ties the center of the arch to the container lid at the rivet. The width of hinge 20, measured in degrees centered at the rivet hole, is one the order of one hundred twenty degrees or more, in order to provide control over the position of nose 14 when the tab is lifted. A range from one hundred degrees to one hundred eighty degrees as a width of hinge 20 is desirable to offset undue recession of nose 14.
When the tab 10 of
The full length arch of
Tab 10 is best employed on a container such as a can, which may be a metal can, and typically on the lid of such can.
In this example,
In summary, an appropriately configured stay-on tab 10 can be mounted on a container in a suitable position to separate the parting line of an opening panel. In each of the described combinations of stay-on tab 10 with a container or container lid, the tab is configured to provide the user with improved finger access for lifting the gripping end of the tab in order to press the opposite, pressing nose against the opening panel 52, 62 at or near the parting line to separate the parting line.
In
In
Economic and pragmatic factors often limit the size of a stay-on tab. These might include a desire to limit material costs, a limited size of the actual container lid body, and a limited clearance available between the gripping end and the rim of the container lid body. These factors gravitate toward placing an upper limit on the size of a stay-on tab regardless of how large user's finger may be. Accordingly, expanding the width of the stay-on tab to enable the use of a concave recess to fully accommodate a large finger or thumb is unlikely to be done. A practical maximum width of the concave opening is thought to be near three-quarters of an inch, which might be used on appropriately large sized and styled container lids. As an example, it may be noted that the food can style of lid 50 allows more room for a larger stay-on tab, correspondingly allowing a larger opening to the concave recess. The beverage can style of lid 60 allows less room for the stay-on tab, favoring the use of a smaller opening to the concave recess.
In addition to offering improved ergonomics, the stay-on tab 10 offers improved efficiency in material utilization due to the U-shaped configuration for finger engagement. Metal savings, or savings of most any other material that is utilized, can be estimated by comparing the tab in either of two ways.
A remainder segment 78 represents a shape savings, which is the difference in area between tabs 10 and 74. Hence,
The nested pattern shows a clear example of good efficiency in utilizing the sheet stock. As each row is formed into a series of cut tab blanks 10, the row also generates scrap, such as at scrap areas 82 that are a part of no tab. Therefore, the efficiency of material usage can be derived by comparing the relative area of scrap 82 to the area of a produced tab blank 10. There is one scrap area 82 per tab blank 10, and this scrap area is about two percent of the area of a tab blank 10.
The middle grouping of tab blanks in
The row arrangement shown in the center of
The staggered column configuration also generates an excess column end scrap 90. This excess column end scrap 90 is due to the inability of this arrangement to equally consume the sheet stock at the edges of alternate columns. The excess end scrap 90 can be estimated to be equal to one entire tab 74 plus one entire combined scrap area 86, 88. The eventual percent of scrap according to the right hand grouping of
By comparison, the blanks for tabs 10 are cut in rows with the nose of one tab nested near the concave edge of the next. This nested configuration produces substantially less scrap than either of the illustrated schemes for forming the commercial blanks 74. The scrap is about two percent of the area of blank 10. It may be projected that variations in tab shape could alter the percent of scrap for either the commercial tab 74 or the concave ended tab 10. However, the overall savings are likely to favor blanks 10, as suggested by comparison of the scrap percentage for either the straight and the staggered row arrangements for the commercial tab 74. The new concave ended tab 10 appears capable of production savings that can be estimated as sixty-six to seventy-five percent of the scrap produced in conventional commercial production. These savings can be equated to similar cost advantages. These prospective savings amounts are subject to variation according to changes and differences in production models versus those used in the foregoing example.
The comparison shown in
A remainder segment 96 represents a shape savings, which is the difference in area between tabs 10 and 92.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be regarded as falling within the scope of the invention as defined by the claims that follow.
