Abstract:
Apparatus and related methods for a container lid include a pull structure affixed to one end of a tearstrip and positioned in an outer flange of the lid, the pull structure having a portion shaped to receive and engage a manipulator such as at least one finger of a user&#39;s hand, to assist the user to initiate tearing of the tearstrip from the lid. The shaped portion of the pull structure is configured to eliminate the need to grip the tearstrip between opposing digits of the user&#39;s hand.

Description:
[0001]    This invention relates to apparatus and methods regarding container lids having tearstrips, and more particularly to providing a pull tab on such a tear strip.  
         BACKGROUND OF THE INVENTION  
         [0002]    Tearstrips are commonly provided to enable relatively easy removal of lids from their associated containers. They can also provide some indication of tamper evidence with respect to the sealed container (e.g., has the sealed container been opened previously). Such tearstrips have been provided within injection molded lids, among others.  
           [0003]    Within injection molded lids, however, it can remain relatively difficult for a user to grasp the end of the tearstrip to initiate removal of the tearstrip. Simple tabs formed at the end of the tearstrip remain relatively unsatisfactory in that regard, at least in comparison to the present invention. Other approaches do not provide a reusable lid to cover the container opening once the tearstrip is removed, require more complicated molding, may be less susceptible to ready stacking and nesting (especially with other existing containers and lids), and have other shortcomings.  
         OBJECTS AND ADVANTAGES OF THE INVENTION  
         [0004]    Accordingly, it is an object of this invention to provide an improved lid and tearstrip combination.  
           [0005]    It is another object of this invention to provide a tearstrip assembly in combination with a lid, including a pull ring molded at one end of the tearstrip. The lid is characterized by a downwardly-depending skirt integrally molded at its periphery, with the pull ring initially positioned within the skirt.  
           [0006]    A further object of this invention is the provision of a container lid having a tamper-indicating tearstrip, the tearstrip being injection molded as an integral part of the lid prior to removal of the tearstrip from the remainder of the lid. The tearstrip includes a pull structure affixed to one end and positioned in an outer flange of the lid, and has a portion shaped to receive at least one finger of a user&#39;s hand to assist the user to initiate tearing of the tearstrip from the lid. Removal of the tearstrip permits opening of the lid from its associated container, and the shaped portion on the tearstrip is configured to eliminate the need to grip the tearstrip between opposing digits on the user&#39;s hand in order to initiate the tearing.  
           [0007]    An additional object of this invention is the provision of a tearstrip having a portion shaped to at least partially wrap around a manipulator and provide selective engagement with the manipulator to assist in tearing of the tearstrip from a lid.  
           [0008]    Yet another object of this invention is the provision of a tearstrip positioned within a lid such that removing the entire tearstrip permits the container to be opened but also leaves a remaining portion of the lid that is capable of covering the corresponding opening in the associated container.  
           [0009]    An additional object of this invention is the provision of a method of closing and opening a container, using a lid having the aforementioned characteristics.  
           [0010]    Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings, which are for the purpose of illustration only. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1A is an isometric view of a container lid assembled with a container (of which only the upper container portion is shown), illustrating various general aspects of prior art tearstrips, with the tearstrip shown partially removed (this FIG. 1A is a copy of FIG. 10 of my U.S. Pat. No. 5,617,968).  
         [0012]    [0012]FIG. 1 is an elevation view of a preferred embodiment of the tearstrip features of the invention, illustrating a circular finger or manipulator opening for the pull structure at an end of the tearstrip.  
         [0013]    [0013]FIG. 2 is similar to FIG. 1, but illustrates one of the many alternative embodiments of the invention, an oval finger or manipulator opening.  
         [0014]    [0014]FIG. 3 is similar to FIGS. 1 and 2, but illustrates another of the many alternative embodiments of the invention, a trapezoidal finger or manipulator opening.  
         [0015]    [0015]FIG. 4 is similar to FIGS.  1 - 3 , but illustrates yet another of the many alternative embodiments of the invention, a generally C-shaped finger or manipulator opening.  
         [0016]    [0016]FIG. 5 is a cross-sectional view along reference line  5 - 5  of FIG. 1. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    [0017]FIGS. 1 and 5 illustrate a preferred embodiment of the invention, and FIGS.  2 - 4  illustrate some of the many alternative embodiments. Broadly, instead of a tab such as tab  42  in FIG. 1A or similar structure that requires a user to grip the end of the tearstrip between a finger and thumb (or other digits on the user&#39;s hands), the invention provides an improved engagement structure for a user&#39;s finger.  
         [0018]    The structure of the invention facilitates easier use for any given tearstrip structure, as compared to conventional tearstrips. Among other things, the improved grippability of the invention permits lids to have thicker (and therefore more rugged and sturdy) tearlines as may be desirable for certain applications, while still permitting a user to remove the tearstrip without undue effort.  
         [0019]    Certain basic concepts regarding tearstrips and related matters are disclosed in my U.S. Pat. No. 5,617,968, and the teachings of that patent are expressly incorporated by reference herein. For example, FIG. 1A illustrates a tearstrip  40  partially removed from a container lid  10  (with lid  10  assembled with a container  12 ). This particular tearline pattern leaves a reclosable tab  70  on the lid. A user typically grasps the end  42  of the tearstrip to initiate tearing and removal of the tearstrip from the lid.  
         [0020]    Although FIG. 1A illustrate a round lid with a sinuous tearline pattern, persons of ordinary skill in the art will understand that the invention is useful on a wide variety of lids and corresponding containers, including without limitation square, rectangular, hinged, non-hinged, recessed, and others.  
         [0021]    In the preferred embodiment of FIG. 1, the end of the tearstrip  30  includes a pull ring or pull structure  32  molded at one end of said tearstrip. Preferably, the pull structure  32  is integrally molded as part of the tearstrip. Also preferably, the pull ring or structure  32  is formed in a downwardly-depending skirt  34  integrally molded at the periphery of the lid  36 , so that the pull ring is initially positioned within said skirt (prior to removal of the tearstrip from the lid).  
         [0022]    Persons of ordinary skill in the art will understand that the preferred tearstrip  30  can function to provide tamper-indicating, and that the tearstrip  30  is preferably injection molded as an integral part of the lid. Moreover, the preferred lid and tearstrip are fabricated by injection molding or similar process, to provide a suitably strong, lightweight closure for a corresponding container. Persons of ordinary skill in the art will understand that the invention may be effectively practiced with a wide variety of materials and fabrication methods.  
         [0023]    Frangible connector portions  38  are preferably provided to retain the pull ring or structure  32  in general alignment with the lid skirt  34  prior to removing the tearstrip. Among other things, this provides tamper-evidencing and helps ensure stackability and nesting (as discussed elsewhere herein) as compared to embodiments without such portions (in which the pull ring  32  might bend toward or away from the center of the lid  36  due to heat shrinkage or the like). As with other preferred features discussed herein, however, the connector portions  38  are not required for practicing and receiving many of the benefits of the invention.  
         [0024]    Reinforcing ribs  39  are preferably provided to improve the strength of the pull ring  32 . Although the ribs  39  are illustrated as being generally vertical, they can be provided horizontally, angled, cross-hatched, or a wide variety of patterns, including not providing any ribs  32  at all.  
         [0025]    Persons of ordinary skill in the art will understand that, as illustrated, the tearstrip  30  is preferably removed from the lid  36  by inserting a finger or other digit in the opening  37 , and pulling in the direction indicated by arrow A in FIG. 1. This is the opposite direction from that shown in FIG. 1A, but persons of ordinary skill in the art will understand that either direction can be effectively utilized. For many applications, the tearing direction will not be important.  
         [0026]    The opening  37  can be provided in any suitable shape. Among the many alternative embodiments are those shown in FIG. 2 (oval shape  50 ), FIG. 3 (trapezoidal shape  52 ), and FIG. 4 (generally C-shaped structure  54 ). By way of further illustration and not by way of limitation, persons of ordinary skill in the art will understand that the finger gripping section on the tearstrip can be provided similarly to the generally C-shape of FIG. 4, but inverted so that the uncompleted portion of the C-loop faces downwardly (rather than upward and to the right, as shown in FIG. 4). In all such embodiments, the tearline aspect of the tearstrip  30  and its removal from the lid  36  can be provided in any suitable manner, such as by a straight or generally horizontal tearline, a sinuous tearline (see FIG. 1A), or otherwise.  
         [0027]    By positioning the pull ring or structure  32  generally within the plane of a downwardly depending skirt  34 , the lid can be readily stacked and nested, before or after assembly on a container, and before or after removal of the tearstrip  30  from the lid  36 . For embodiments in which it is desirable to reuse the lid to cover the container opening after the tearstrip has been removed, the entire tearstrip can be located within the skirt  34  about the periphery of the lid  36 .  
         [0028]    A related preferred method of using the tearstrip of the invention involves providing a lid having the aforementioned characteristics, assembling the lid on a corresponding container, engaging at least one finger with the shaped portion of the pull structure, pulling with the at least one finger to tear the tearstrip from the lid, and removing the lid from the container. Prior to the engaging step, the sealed container can be transported, stored, or otherwise handled and processed.  
         [0029]    Persons of ordinary skill in the art will understand that the tearstrip can be torn from the lid or otherwise manipulated by things other than human fingers. Although much of the description herein focuses on a user&#39;s fingers and other digits on the user&#39;s hands, the relevant tearstrip portion can also be considered to be shaped to at least partially wrap around a manipulator (such as a finger, pencil, hook, etc.) to provide selective engagement with the manipulator to assist in tearing of the tearstrip from a lid. In other words, instead of engaging the shaped portion with your finger or fingers, you can hook it with a tool or other device.  
         [0030]    Preferably, the manipulator-engaging portion (such as illustrated in FIGS.  2 - 5 ) includes a return portion angled by more than 90 degrees with respect to a lengthwise axis of the tearstrip. By “bending back” in the direction of the tearstrip, the return portion provides an effective hook for engaging a manipulator (again, such as a hook, screwdriver, finger, etc.).  
         [0031]    Although the preferred embodiment of the invention has been described with some specificity, the description and drawings set forth herein are not intended to be delimiting, and persons of ordinary skill in the art will understand that various modifications may be made to the embodiments discussed herein without departing from the scope of the invention, and all such changes and modifications are intended to be encompassed within the appended claims.