AU2002307289A1 - Pull tab on tear strip on plastic cover - Google Patents

Description

PULL TAB ON TEAR STRIP ON PLASTIC COVER

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:

Tearstrips are commonly provided to enable relatively easy removal of lids from their associated containers. They can also provide some indication of tamper evi¬

dence with respect to the sealed container (e.g., has the sealed container been opened pre¬

viously). Such tearstrips have been provided within injection molded lids, among others.

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:

Accordingly, it is an object of this invention to provide an improved lid

and tearstrip combination. 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.

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'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's hand in

order to initiate the tearing.

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.

Yet another object of this invention is the provision of a tearstrip posi¬

tioned 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 corre-

sponding opening in the associated container. 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.

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:

FIG. 1 A 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).

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.

FIG. 2 is similar to FIG. 1 , but illustrates one of the many alternative

embodiments of the invention, an oval finger or manipulator opening.

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.

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. FIG. 5 is a cross-sectional view along reference line 5-5 of FIG. 1.

Description of Preferred Embodiment:

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's hands), the invention

provides an improved engagement structure for a user's finger.

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.

Certain basic concepts regarding tearstrips and related matters are dis-

closed in my U.S. Pat. No. 5,617,968, and the teachings of that patent are expressly

incorporated by reference herein. For example, FIG. 1 A 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.

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, rectan¬

gular, hinged, non-hinged, recessed, and others.

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).

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 prefera¬

bly 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.

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.

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.

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.

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. 1 A), or otherwise.

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.

A related preferred method of using the tearstrip of the invention involves

providing a lid having the aforementioned characteristics, assembling the lid on a corre¬

sponding 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 remov¬

ing the lid from the container. Prior to the engaging step, the sealed container can be

transported, stored, or otherwise handled and processed.

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's fingers and other digits on the user's

hands, the relevant tearstrip portion can also be considered to be shaped to at least par¬

tially 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.

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 length-

wise 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.).

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 modifica¬

tions 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.

Claims (11)

CLAIMSWhat is claimed is:

1. A tearstrip assembly in combination with a lid, including a pull

ring molded at one end of said tearstrip, said lid having a downwardly-depending skirt

integrally molded at its periphery, said pull ring initially positioned within said skirt.

2. A container lid having a tearstrip, said tearstrip being injection

molded as an integral part of said lid prior to removal of said tearstrip from the remainder

of said lid, said tearstrip including a pull structure affixed to one end and positioned in an

outer flange of said lid, said pull structure having a portion shaped to receive at least one

finger of a user' s hand to assist the user to initiate tearing of said tearstrip from said lid,

said removal of said tearstrip permitting opening of said lid from its associated container,

said shaped portion configured to eliminate the need to grip said tearstrip between

opposing digits on the user's hand in order to initiate said tearing.

3. The lid of Claim 2 or Claim 9, in which said shaped portion of said pull structure is not oval.

4. The lid of Claim 2 or Claim 9, in which said shaped portion of said pull structure is generally C-shaped.

5. The lid of Claim 4, in which said generally C-shaped pull structure

portion constitutes an uncompleted loop, in which said uncompleted portion of said loop is directed generally downwardly.

6. The lid of Claim 2 or Claim 9, including frangible connections

between said pull structure and adjacent portions of said lid, said frangible connections

providing tamper-evidencing and helping to hold said pull structure in general alignment

with said adjacent portions of said lid prior to tearing said tearstrip.

7. The lid of Claim 2 or Claim 9, in which said tearstrip is positioned

within said lid such that removal of said entire tearstrip leaves a remaining portion of said

lid that is capable of covering the corresponding opening in the associated container.

8. A method of closing and opening a container, including the steps

of:

providing a container lid having a tearstrip, said tearstrip being injection

molded as part of said lid prior to removal of said tearstrip from the remainder of said lid,

said tearstrip including a pull structure affixed to one end and positioned in an outer

flange of said lid, said pull structure having a portion shaped to receive at least one finger

of a user's hand to assist the user to initiate tearing of said tearstrip from said lid, said

removal of said tearstrip permitting opening of said lid from its associated container, said

shaped portion configured to eliminate the need to grip said tearstrip between opposing

digits on the user's hand;

assembling said lid on said container;

engaging at least one finger with said shaped portion of said pull structure;

pulling with said at least one finger to tear said tearstrip from said lid; and

removing said lid from said container.

9. A container lid having a tearstrip, said tearstrip being injection

molded as an integral part of said lid prior to removal of said tearstrip from the remainder

of said lid, said tearstrip including a pull structure affixed to one end and positioned in an

outer flange of said lid, said pull structure having a manipulator-engaging portion to

assist in tearing of said tearstrip from said lid, said removal of said tearstrip permitting

opening of said lid from its associated container, said manipulator-engaging portion

including a return portion angled by more than 90 degrees with respect to a lengthwise

axis of said tearstrip so that said return portion provides an effective hook for engaging a

manipulator.

10. A method of closing and opening a container, including the steps

of:

providing a container lid having a tearstrip, said tearstrip being injection

molded as part of said lid prior to removal of said tearstrip from the remainder of said lid,

said tearstrip including a pull structure affixed to one end and positioned in an outer

flange of said lid, said pull structure having a portion shaped to at least partially wrap

around a manipulator and provide selective engagement with said manipulator to assist in

tearing of said tearstrip from said lid, said removal of said tearstrip permitting opening of

said lid from its associated container;

assembling said lid on said container;

engaging at manipulator with said shaped portion of said pull structure;

pulling with said manipulator to tear said tearstrip from said lid; and removing said lid from said container.

11. The method of Claim 10, in which said manipulator-engaging por¬

tion includes a return portion angled by more than 90 degrees with respect to a lengthwise

axis of said tearstrip so that said return portion provides an effective hook for engaging a

manipulator.