AU487724B2 - Improvements in or relating to containers - Google Patents

Description

8122 6n75

This invention is concerned with improvements in or relating to containers, more especially to containers of the so-called easy-open type and closure members therefor.

In recent years there has been a great change in the method of opening containers, e.g. cans for beer or soft drinks, in that such containers have been provided

with tear strips, usually in an end wall thereof, and finger tabs have been connected with these tear strips

thus to facilitate the tearing of the strip, and thus the

opening of the container. A major problem of such tear strips and finger tabs is, however, that unless the user

is litter-conscious, the strips and tabs are thrown away in public places, which not only detracts from the appearance

of such places, but may also be of a hazard to both

persons and property. A further disadvantage of such containers may also arise in that, if the lines defining

the tear strips are too deep, it is possible that the container leaks.

It is one of the various objects of the present invention to provide an improved container of the easy-

open type comprising a section by which an opening into

the container is provided, but which section cannot be

ripped off and thrown away. It is a further one of the various objects of the invention to provide an improved

container closure member having such a section, and a still

further one of the various objects of the present invention

to provide a method of making such a container closure, member.

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The invention provides a container of the easy-

open type comprising a chamber defined by side and end

walls, -one of which walls comprises a section which, by

the application of manual pressure thereto, can be pushed

inwardly into the container, thus to provide an opening

into said chamber, wherein there is formed in said one

wall a channel having two wall portions meeting at the

base of the channel, one of which wall portions is inclined

at an angle less than 900 away from the plane of the area

of the wall surrounding the channel and has, extending

therealong, a line of weakness which at least partly defines

said section, and the other of which wall portions, also

inclined away from said plane, forms part of said section,

and further wherein the line of weakness is provided by

an indentation formed in an inner surface of said one wall

portion, said indentation providing a thin web, integral

with the remainder of said wall portion and, extending

from said web, a first face which extends normally, or

substantially normally, to the aforementioned plane, and

a second face inclined to said first face, and the web

being rupturable by the application of manual pressure

to the section as aforesaid.

The wall of the container, which wall comprises

said section, is preferably an end wall, although it is

envisaged that the invention in its broadest aspects is

also applicable to containers where the push-in section

is located in a wall other than an end wall.

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The invention further provides a container

closure member by which one end of a container can be closed

to form a container of the easy-open type and which comprises

a section which, by the application of manual pressure

thereto, can be at least partially separated from the

remainder of the wall and, when the member forms part of

a closed container, be pushed inwardly into such container,

thus to provide an opening into such container, wherein

said member comprises a wall in which is formed a channel

having two wall portions meeting at the base of the channel,

one of which wall portions is inclined at an angle less than 900 away from the plane of the area of the wall

surrounding the channel and has, extending therealong,

a line of weakness at least partly defining said section,

and the other of which wall portions, also inclined away

from said plane, forms part of said section, and further

wherein the line of weakness is provided by an indentation

extending along a surface of said one wall portion (which

surface constitutes an inner surface of the member, when

the member forms part of a closed container), said

indentation providing a thin web integral with the

remainder of said wall portion and, extending from said

web, a first face which extends normally, or substantially

normally, to the aforementioned plane, and a second face

inclined to said first face, and the web being rupturable

by the application of manual pressure to the section as

aforesaid.

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The channel formed in the member is preferably

continuous, thus defining a closed figure. Alternatively,

however; the channel may extend e.g. from an edge of the

member so that the edge of the member itself defines part

of the section. Again, alternatively, the channel may

follow merely along a line which is not continuous, the

channel gradually tapering in depth.

In addition to the first and second faces

aforementioned, the indentation preferably further comprises

a further face intermediate the first and second faces and

extending at substantially a right angle from the first

face. The width of this intermediate face is preferably

between .001 and .002 inch.

The line of weakness formed in said one wall

portion preferably extends only partially along said

wall portion, so that a "bridge" is formed between the

section and the remainder of the wall, which "bridge"

provides a hinge for the section. Furthermore, the indentation preferably increases in depth away from

the "bridge" and has a maximum depth in a position

opposite to the "bridge". In this manner a separation-

initiating portion of the section is provided opposite

the "bridge".

The invention also provides a method of making

container closure member by which one end of a container

,an be closed thus to form a container of the easy-open

;ype and which comprises a section which, by the application

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of manual pressure thereto, can be at least partially separated from the remainder of the wall and, when the member forms part of a closed container, be pushed inwardly into such container, thus to provide an opening into such

container, the method comprising the steps of forming in a

wall of a closure member blank a channel having two wall

portions meeting at the base of the channel, one of which

wall portions is inclined at an angle less than 900 away from the plane of the area of the wall surrounding the channel, and providing a line of weakness in said one wall portion by forming an indentation in one surface thereof (which one surface will constitute an inner surface of the

member, when the member forms part of a closed container),

the indentation extending along said one wall portion

and providing a thin web integral with the remainder

of said wall portion and, extending from said web, a

first face which extends normally, or substantially

normally, to the aforementioned plane, and a second

face inclined to said first face, the line of weakness at least partly defining said section, and the other of

said wall portions forming the channel also being inclined away from said plane and forming part of said section.

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In carrying out the above method, the line of

weakness is preferably formed by an indenting die and

a counte-die having a portion complementary to said

doepsee4einin the blank, the indenting die comprising a vertical edge, a flat indenting face, and a further edge

inclined to said face, the die engaging the blank so

that a correspondingly shaped indentation is formed therein in such a manner that one face formed by the

indentation extends normally, or substantially normally, to the aforementioned plane as aforesaid. Preferably

the indenting face has a width between .001 and .002 inches. To illustrate the invention, there now follows

a detailed description, to be read with reference to the drawingsa ompanying tho previoional opecificatin, of

a container, a container closure member and a method of

making such a container closure member, hereinafter

referred to respectively as the "illustrative container", the "illustrative member" and the "illustrative method".

It will of course be appreciated that this illustrative

container, this illustrative member and this illustrative

method have been selected for description merely by way

of exemplification of the invention and not by way of

limitation thereof.

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In the drawings

Figure 1 is a perspective view of the illustrative

container, with a push-in section of the closure member

thereof in a closed condition;

Figure 2 is a perspective view similar to Figure 1, but showing the push-in section pushed inwardly to provide an opening into the container; and

Figures 3, 4 and 5 illustrate three stages in an

indenting operation forming part of the illustrative method.

.The illustrative container has a cylindrical body

(Figures 1 and 2) and is closed at one end by a wall in

the form of a lid 14 having a rim 12, said 14d and rim

being constituted by the illustrative container closure

member. Formed in the'lid, adjacent.the rim, is a continuous

channel 18 which comprises an inner wall portion 20 and'an

outer wall portion 22 which meet at a base 24. The outer

wall portion of the channel is inclined at an angle less

than 900 away from the plane of thu area of the lid

surrounding the channel. In the illustrative member

the channel is generally U-shaped in cross-section.

The outer wall portion 22 is provided with a

line of weakness which comprises an indentation made in

the inner surface of the outer wall portion 22 and which

thus defines a section 16 (Figures 1 and 2) which can

be pushed inwardly into the illustrative container, by

the application of manual pressure thereto, thus to

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provide an opening in the container, as seen in Figure 2.

The indentation does not extend along the whole of the length

of the outer wall portion, so that a "bridge" is provided

between the said section 16 and the remainder of the lid

14, thus to provide a hinge H for the section, serving to

prevent the section from falling into the container when

the section is partially separated from the lid by the

application of manual pressure thereto as aforesaid.

The indentation provides a thin web 38 integral

with the outer wall portion 22 and rupturable by the

application of manual pressure to the section as aforesaid.

In addition the indentation comprises a first face 46

which extends normally, or substantially normally, to the

aforementioned plane of the area of the lid surrounding the

channel, a second face 48, which is inclined to the face 46,

and a further face 47, intermediate the faces 46, 48 and

extending substantially at a right angle from the first face

46. The width of said intermediate is .001 to .002 inch.

The depth of the indentation varies along its

length from a minimum, to provide the hinge h, to a

maximum, diagonally opposite the hinge portion H. In

this manner, a separation-initiating portion is provided

at the position diagonally opposite the hinge H. To

assist in indicating the separation-initiating portion,

suitable indicia,.e.g. an.arrow (not shown), are used to

indicate the locality of maximum depth, at which manual

pressure is most readily effective to initiate rupture of

the web 38. Once the rupture of the web has been initiated

487,7 24

81. 22 6

continued tearing of the metal along the remainder of the indentation requires substantially less pressure. Referring to Figures 3 to 5 of the drawings, in. carrying out the illustrative method, a_forming die

(not shown) and a counter-die 26 are used in a first stage to form the channel shaped 4iz~ees4:on 18 in a lid blank. The counter-die 26 has an annular rib which is shaped generally to the shape to be imparted to the blank in forming the depree.I 418, and the forming die has a complementary shaped recessed portion for cooperating therewith, With the blank-thus formed'with aj4-epeeele~ and with the blank supported on the counter-die 26, the indenting operation is carried out using an indenting die 28. The indenting die 28 (Figures 3,to 5) has a vertically disposed cutting edge 30, an indenting -face '32 sad a longer inclined indenting edge 34 extending outwardly from the face 32. The indenting face has a

uniform width of the order of .001 to .002 inches.

The indenting die has a yieldingly compressible rubber pad 36 of uniform thickness located within the operating locality, that is within the cutting edge 30. The pad 36

engages with the blank and holds it on the annular rib of

the counter-die during approach movement between the dies. As shown in Figure 3, the amount by which the indenting face 32 projects above the base of the die 28 varies progressively from a maximum projection, as seen on the righthand side of the die periphery in Figures 3

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81. 22 6

to 5, to a minimum on the lefthand side. In this manner,

the depth of the indentation formed in the outer wall

portion 22 is varied along its length, and indeed from a

minimum, to provide the hinge H, to a maximum, diagonally

opposite the hinge H. In this manner, as above stated,

a separation-initiating portion is provided at the position

diagonally opposite the hinge H.

The first face 46 thus produced by the indenting

operation extends vertically, that is parallel or

substantially parallel to the direction of relative

movement of approach between the two dies, and also normally,

or substantially normally, to the plane of the area of the

lid surrounding the channel, while the intermediate face

47 extends at right angles to the face 46, being formed

by the indenting face 32, and the second face 48 is

angularly inclined, to the first face 46, being created

by the indenting edge 34.

When the indenting operation is complete, the

dies 26, 28 are separated one from the other, the pad 36

ensuring that the lid remains supported by the counter-die

26. As the separation takes place, it will be appreciated,

the right angle disposition of the two faces is partly

reduced, as indicated in Figure 5, as residual tension in

the material of the wall is dispelled by the separation.

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The claims defining the invention are as

follows

1. A container of the easy-open type comprising

a chamber defined by side and end walls, one of which walls

comprises a section which, by the application of manual

pressure thereto, can be pushed inwardly into the container,

thus to provide an opening into said chamber, wherein there

is formed in said one wall a channel having two wall portions

meeting at the base of the channel, one of which wall

portions is inclined at an angle lass than 900 away from

the plane of the area of the wall surrounding the channel

and has, extending'therealong, a line of weakness which

at least partly defines said section, and the other of

which wall portions, also inclined away from said plane,

forms part of said section, and further wherein the line

of weakness is provided by an indentation formed in an

inner surface of said one wall portion, said indentation

providing a thin web, integral with the remainder of said

wall portion and, extending from said web, a first face

which extends normally, or substantially normally, to the aforementioned plane, and a second face inclined to said

first face, and the web being rupturable by the application

of manual pressure to the section as aforesaid.

2. A container according to claim 1 wherein

the wall which comprises the section is an end wall.

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81. 22 6ns

3. A container closure member by which one

end of-a container can be closed to form a container of

the easy-open type and which comprises a section which,

by the application of manual pressure thereto, can be at least partially separated from the remainder of the.

wall and, when the member forms part of a closed container,

be pushed inwardly into such container, thus to provide

an opening into such container, wherein said member

comprises a wall in which is formed a channel having

two wall portions meeting at the base of the channel,

one of which wall portions is inclined at an angle less

than 900 away from the plane of the area of the wall

surrounding the channel and has, extending therealong,

a line of weakness at least partly defining said section,

and the other of which wall portions, also inclined away

from said plane, forms part of said section, and further wherein the line of weakness is provided by an indentation extending along a surface of said one wall portion (which

surface constitutes an inner surface of the member, when the member forms part of a closed container), said indentation providing a thin web integral with the

remainder of said wall portion and, extending from said

web, a first face which extends normally, or substantially

normally, to the aforementioned plane, and a second face

inclined to said first face, and the web being rupturable

by the application of manual pressure to the section as

aforesaid.

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4- A member according to claim 3 wherein the

channel is continuous and thus defines a closed figure.

A member according to either one of

claims 3 and 4 wherein the indentation further provides

a further face intermediate the first and second faces

and extending at substantially a right angle from the

first face.

6. A member according to claim 5 wherein

the width of the intermediate face is between .001 and .002 inch.

7. A member according to any one of Claims 3

to 6 wherein the line of weakness extends only partially

along said one wall portion so that a "bridge" is formed

between the section and the remainder of the wall.

8. A member according to Claim 7 wherein

the depth of the indentation increases away from said

"bridge" and has a maximum depth in a position opposite

to said "bridge".

9. A method of making a container closure

member by which one end of a container can be closed thus

to form a container of the easy-open type and which comprises a section which, by the application of manual pressure

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thereto, can be at least partially separated from the

remainder of the wall and, when the member forms part

of a closed container, be pushed inwardly into such

container, thus to provide an opening into such container,

the method comprising the steps of forming in a wall of

a closure member blank a channel having two wall portions

meeting at the base of the channel, one of which wall

portions is inclined at an angle less than 900 away from

the plane of the area of the wall surrounding the channel,

and providing a line of weakness in said one wall portion

by forming an indentation in one surface thereof (which

one surface will constitute an inner surface of the member,

when the member forms part of a closed container), the

indentation extending along said one wall portion

and providing a thin web integral with the remainder

of said wall portion and, extending from said web, a

first face which extends normally, or, substantially

normally, to the aforementioned plane, and a second

face inclined to said first face, the line of weakness

at least partly defining said section, and the other of

said wall portions forming the channel also being inclined

away from said plane and forming part of said section.

487.7 24

Claims (1)

1. 81. 22 6

   A method according to Claim 9 wherein the

   line of weakness is formed by an indenting die and a

   counter-die having a portion complementary to said depression

   in the blank, the indenting die comprising a vertical edge,

   a flat indenting face, and a further edge inclined to said

   face, the die engaging the blank so that a correspondingly shap(

   indentation is formed therein in such a manner that one face

   formed by the indentation extends normally, or substantially

   normally, to the aforementioned plane.

   11. A method according to Claim 10 wherein the

   indenting face has a width between .001 and .002 inches.

   12. A method of making a container closure member

   carried out substantially as hereinbefore described with reference to the accompanying drawings.

   13. A container closure member made by a method

   according to any one of Claims 9 to 12.

   14. A container having a closure member according

   to any one of Claims 3 to 6 and 13.

   DATED THIS 14th day of MAY, 1975

   EDWD. WATERS SONS Patent Attorneys Queen Street, MELBOURNE.

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