Can End With Retained Tear Strip

Abstract

An easy opening container wall comprising a container wall of sheet material which is weakened in a preselected zone to define a wall segment bendable inwardly of the container wall about a bend line and a tab attached to the container wall for bending the wall segment inwardly. The tab can be pivoted through approximately 180.degree. to thereby bend the wall segment inwardly approximately the same amount to form an opening in the container wall.

Description

BACKGROUND OF THE INVENTION

The typical easy opening container wall has a tear portion which is removed by a tab to form an opening in the container wall. Unfortunately, severed tear portions and tabs are often carelessly discarded, and this has created a litter problem.

To solve this problem, it has been proposed to use an easy opening container wall in which the tear portion is not completely removable from the container wall. This retained tab concept is generally regarded as a good approach to the solution of the litter problem and much work has been done in an attempt to perfect it.

One of the most significant problems with the retained tab concept is that the edges of the partially severed tear portion are exposed and relatively sharp and jagged. These exposed edges are a potential source of injury to the consumer.

SUMMARY OF THE INVENTION

The present invention provides an easy opening container wall of the retained tab type in which the danger heretofore present from the sharp edges of the partially removed tear portion is completely eliminated. This is accomplished by constructing the easy opening container wall so that the tear portion or wall segment is forced inwardly of the container wall during the opening operation. The wall segment remains within the container so that the sharp edges thereof are inside of the container and cannot injure the user.

In the opening operation, the tab and the wall segment are pivoted through approximately 180.degree. to an inverted position to thereby form an opening in the container wall. In the inverted position the wall segment underlies and abuts the inner face of the container wall, and the tab extends from a location underlying the container wall across the opening to a location on the public side of the container wall. In this position, the tab is flat against the container wall and cannot interfere with removal of the contents of the container.

The typical container wall has a peripheral attaching flange which projects axially of the container wall on the public side thereof. Preferably, the tab and the wall segment are oriented so that the tab can be substantially inverted without interference from the attaching flange. In the inverted position, the tab preferably lies completely within the area surrounded by the attaching flange.

The tab and the wall section must be sized and oriented so that inversion of the tab does not completely close off the opening in the container wall or otherwise interfere with pouring of the contents of the container from the opening. In addition, the opening should be adjacent the attaching flange. In a preferred form of the present invention, the wall segment is adjacent the attaching flange and the tab and the wall segment are pivoted about a bend line which forms an acute angle with the longitudinal axis of the portion of the tab outside the wall segment. This provides a pouring opening close to the periphery of the container wall and assures that the inverted tab will not contact the attaching flange.

Another feature of the present invention is that the tab protrudes only a minimum amount from the container wall in the inverted position. This is accomplished, in part, by providing a depressed panel or depressed section in the container wall. At least a portion of the wall segment is located in the depressed panel, and the depressed panel is of sufficient area to receive the portion of the tab which overlies the public side of the container wall in the inverted position of the tab. Another structural feature contributing to this overall purpose is a bend region formed in the tab. The bend region lies closely adjacent a section of the rim of the opening when the tab is inverted. The bend section and the adjacent section of the rim are sized and oriented so as to allow maximum pivotal movement of the tab before the tab engages the rim of the opening.

The container wall preferably has a second depressed panel or depressed section for receiving the offset end portion of the tab prior to opening the container. This prevents the tab from projecting unduly on the public side of the container wall prior to formation of the opening in the container wall. For some embodiments of the invention, the offset of the end portion of the tab can be at a maximum at one end of the bend portion and at a minimum at the other end of the bend portion. Preferably, the second depressed section is correspondingly shaped so as to minimize the volume reduction of the container as a result of the depressed sections.

The tab can advantageously be constructed of sheet material and reinforced longitudinally against bending by beads or curls formed along the periphery of the tab. To provide a smooth surface on the tab when the container is open, the curls are preferably formed by turning of the sheet material upwardly and inwardly. Accordingly, in the inverted position of the tab, the curls project downwardly thereby leaving a smooth surface on the public side of the container wall.

To facilitate opening of the container wall, the tab is preferably attached to the wall segment at a region thereof which is not depressed inwardly. This provides some free lift, i.e., it permits the outer end of the tab to be raised slightly before it forcibly engages the sheet material along the weakened zone. In addition, a bend score line or similar nonrupturable weakening means may be provided along the bend line about which the tab and the wall segment are to bend.

The invention can best be understood by reference to the following description taken in connection with the accompanying illustrative drawings in which:

FIG. 1 is a top plan view of one form of a tab of this invention.

FIG. 2 is a side elevational view taken generally along line 2--2 of FIG. 1.

FIG. 3 is an enlarged fragmentary view taken generally along line 3--3 of FIG. 2.

FIG. 4 is a top plan view of one form of a container wall of this invention.

FIGS. 5-9 are enlarged fragmentary sectional views taken generally along lines 5--5, 6--6, 7--7, 8--8 and 9--9 of FIG. 4, respectively, and showing the variations in depth of one of the depressed panels.

FIG. 10 is an enlarged sectional view taken generally along line 10--10 of FIG. 4.

FIG. 11 is a top plan view of an easy opening container wall constructed in accordance with the teachings of this invention.

FIG. 12 is a top plan view similar to FIG. 11 with the tab pivoted to form an angle of about 90.degree. with the container wall and with an opening formed in the container wall.

FIG. 13 is a top plan view of the easy opening container wall in the fully open position, i.e., with the tab and wall segment substantially inverted.

FIG. 14 is an enlarged fragmentary sectional view taken generally along line 14--14 of FIG. 11 and showing the easy opening container wall mounted on a can body.

FIG. 15 is an enlarged fragmentary sectional view taken generally along line 15--15 of FIG. 12.

FIG. 16 is a sectional view taken generally along line 16--16 of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 11 shows an easy opening container wall 11 constructed in accordance with the teachings of this invention. The easy opening container wall 11 generally includes a container wall 13 and a tab 15.

The container wall 13, which can best be understood from reference to FIGS. 4-10, is constructed of sheet material such as aluminum or an aluminum alloy. In the embodiment illustrated, the container wall 13 is in the form of a can end and has a peripheral attaching flange 17 for attaching the container wall to a can body 19 (FIG. 14).

The container wall 13 has depressed panels or depressed sections 21 and 23. The depressed panel 21 has a peripheral wall 25 and a bottom wall 27 (FIG. 10). A nondepressed region 29 in the form of a finger or projection extends into the depressed panel 21 as shown in FIG. 4. A rupturable score line 31 which includes a straight leg 33 and a curved leg 35 are provided in the bottom wall 27. As shown in FIG. 4, the legs 33 and 35 intersect to form a corner 37. A nonrupturable score line 39 is formed across the nondepressed region 29 and is oriented so that, if it were longer, it would substantially intersect the remote ends of the legs 33 and 35. The score line 39 is scored to a lesser depth than the score line 31 and accordingly in ordinary use the sheet material along the score line 39 will not rupture. The score lines 31 and 39 cooperate to define a tear portion or wall segment 41 which is pivotable inwardly about a bend line which is partially defined and which extends along the nonrupturable score line 39.

The wall segment 41 is comprised of a section within the depressed panel 21 and of the nondepressed region 29. The depressed panel 21 has a relatively large region 43 which lies outside of the wall segment 41. A hollow rivet 45 is formed integrally with the sheet material of the nondepressed region 29 for attaching the tab 15 to the container wall 13.

The depressed panel 23 has a bottom wall 47 and a peripheral wall 49 of varying height. FIGS. 5-9 show generally how the height of the peripheral wall 49 varies. In the embodiment illustrated, the peripheral wall is progressively reduced in height from the line 5--5 (FIG. 4) counterclockwise to the line 9-9 (FIG. 4). As shown in FIG. 5, the peripheral wall 49 at that position is substantially full height and as shown in FIG. 9 the peripheral wall 49 is almost eliminated at that position. Similarly, a section 50 of the peripheral wall is progressively increased in height from the line 9--9 (FIG. 4) to a corner 51 of the depressed panel 23.

The tab 15 (FIGS. 1-3) in the embodiment illustrated is a lever tab and is integrally constructed from a single piece of sheet material. A peripheral region of the sheet material of the tab is curled upwardly and inwardly to form a peripheral reinforcing bead or curl 53 which extends substantially completely around the tab and which is interrupted to form a rupturing nose 55. The tab 15 may be strengthened adjacent the rupturing nose 55 by one or more ribs 57 (two being illustrated) which in the embodiment illustrated are formed upwardly in the sheet material of the tab. The sheet material from which the tab 15 is constructed may be, for example, an aluminum alloy or steel. The tab 15 has a handle or lifting end 59 and a rivet receiving aperture 61 intermediate the ends of the tab for receiving the rivet 45 (FIG. 10).

The tab 15 has a bend portion 63 which forms an acute angle with the longitudinal axis of the tab 15 and which divides the tab into sections 65 and 67. The bend portion 63 offsets the section 65 downwardly relative to the section 67. The amount of the offset is maximum at a location 69 at one end of the bend portion 63 and progressively decreases to a minimum at a location 71 at the opposite end of the bend portion 63.

FIGS. 11 and 14 show the tab 15 mounted on the container wall 13 by the rivet 45 which projects through the aperture 61 of the tab. The tab 15 is oriented relative to the container wall 13 so that the rupturing nose 55 overlies the corner 37 and so that the section 65 of the tab is received within the depressed panel 23. The bend portion 63 of the tab extends generally along the wall section 50 of the depressed panel 23. The degree of offset provided by the bend portion 63 between the locations 69 and 71 (FIG. 1) corresponds to the change in height of the wall section 50 so that the tab 15 projects a minimum amount above the container wall 13. By tailoring the depth of the panel 23 to the shape of the section 65 and of the bend portion 63 of the tab 15, the volume reduction of the container 19 is minimized. The purpose of the offset provided by the bend portion 63 is described hereinbelow.

The longitudinal axis of the tab forms an acute angle with the score line 39 and with the bend line which is formed along the score line 39 during the opening operation. The tab 15 extends at an angle across the wall segment 41 so as to effectively asymmetrically divide the wall segment.

To open the container wall 13, the lifting end 59 of the tab is raised above the container wall 13 to thereby tend to pivot the tab generally about the score line 39. This causes the rupturing nose 55 to apply a downward force to the wall segment 41 at the cOrner 37 to thereby rupture the sheet material along the legs 33 and 35 of the rupturable score line 31. This forms an opening 73 in the container wall (FIGS. 12 and 15). The wall segment 41 and the tab 15 both pivot about the nonrupturable score line 39 which assists in the formation of a bend line.

To complete the opening process, the tab 15 and the wall segment 41 are pivoted together about the score line 39 approximately an additional 90.degree. to the position shown in FIGS. 13 and 16. In this position, the tab 15 and the wall segment 41 are substantially inverted relative to the positions which they occupied prior to initiation of the opening process. A portion of the tab 15 underlies the container wall 13, a second portion of the tab projects at an angle across the opening 73 to divide the opening into a relatively large pouring opening 75 and a relatively small vent opening 77, and a third portion of the tab which includes substantially all of the section 65 is received within the depressed panel 21.

The wall segment 41 has severed edges as a result of rupture of the sheet material along the score line 31; however, these edges are entirely within the container 19 so they do not represent a potential source of injury. The tab 15 can be pivoted through substantially 180.degree. from the position shown in FIG. 11 to the position shown in FIG. 13 without interference from the attaching flange 17. The pouring opening 75 is located relatively close to the periphery of the container wall 13 and the tab 15 does not interfere with pouring out of the opening 75. Because the section 65 of the tab is received in the depressed panel 21, protrusion of the tab axially of the container 13 is minimized.

The purpose of the bend portion 63 is to prevent contact of the tab 15 on the rim 79 of the opening. Such contact would limit the degree of pivotal movement of the tab 15 and cause some axial protrusion of the tab. However, by appropriately offsetting the section 65, the tab will not contact the rim 79. The nature and type of the offset of the tab 15 will vary depending upon various factors including the size, shape and orientation of the tab and the wall segment 41. Accordingly, the bend portion 63 is shown merely by way of example as a bend portion which is satisfactory for the illustrated embodiment of the invention.

Although an exemplary embodiment of the invention has been shown and described, many changes, modifications and substitutionS may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

Claims

We claim:

1. An easy opening container wall comprising:

a container wall of sheet material, the sheet material of said container wall being weakened in a preselected zone to define one wall segment bendable inwardly of the container wall about a bend line;

a tab;

means for attaching the tab to the wall segment with at least a portion of the tab overlying at least a portion of the wall segment, said tab being pivotable through a sufficient number of degrees to at least substantially invert said tab, such pivotal movement of the tab severing said sheet material along said preselected zone and bending the wall segment inwardly generally about said bend line to at least substantially invert the wall segment whereby an opening is formed in said container wall;

said tab and said wall segment being sized and oriented so that a portion of said opening of sufficient size to constitute a pouring opening is uncovered by said tab after said tab and said wall segment are inverted; and

said tab when inverted lying entirely within the peripheral outline of said container wall.

2. An easy opening container wall as defined in claim 1 wherein said tab is constructed of sheet material, a peripheral region of the sheet material of said tab being turned upwardly and inwardly to define a peripheral reinforcing bead whereby when said tab is inverted said peripheral region of the tab is turned downwardly.

3. An easy opening container wall as defined in claim 1 wherein said container wall includes a peripheral axially protruding attaching flange which at least substantially circumscribes a region of the container wall, said tab having a second portion lying outside of the wall segment and having an axis which forms an acute angle with said bend line, said tab being completely within the area circumscribed by said attaching flange when said tab is inverted.

4. An easy opening container wall as defined in claim 1 wherein said tab when inverted projects completely across the opening and a section of said tab overlies the container wall, said tab having a bend portion adjacent the rim of the opening when the tab is inverted which allows said section of the tab to be closer to the container wall than if said bend portion were not provided.

5. An easy opening container wall as defined in claim 4 wherein said container wall includes a depressed region for receiving said section of said tab prior to pivoting of the tab to form said opening.

6. An easy opening container wall as defined in claim 1 wherein said container wall includes a depressed section formed downwardly in said container wall, at least a major portion of said wall segment being formed in said depressed section, said tab when inverted having first, second and third sections, said first section being on the inner side of the container wall, said second section overlying the opening and said third section being on the outer side of the container wall, said third section of said tab lying entirely within the area of said depressed section.

7. An easy opening container wall comprising:

a container wall of sheet material, the sheet material of said container wall being weakened in a preselected zone to define a wall segment bendable inwardly of the container wall about a bend line;

said container wall having a depressed section therein, at least a major portion of said wall segment being located in said depressed section;

a tab;

means for attaching the tab to the container wall with at least a portion of the tab overlying at least a portion of the wall segment, said tab being pivotable through a sufficient number of degrees to at least substantially invert said tab, such pivotal movement of the tab severing said sheet material along said preselected zone and bending the wall segment inwardly generally about said bend line to at least substantially invert said wall segment whereby an opening is formed in said container wall;

said tab when inverted projecting completely across said opening and having a section which overlies said container wall, said section of said tab lying entirely within the area of said depressed section; and

said tab and said wall segment being sized and oriented so that a portion of said opening of sufficient size to constitute a pouring opening is uncovered by said tab after said tab and said wall segment are inverted.

8. An easy opening container wall as defined in claim 7 wherein said tab has a bend portion adjacent the rim of the opening when the tab is inverted which causes said section of the tab to be closer to the container wall than if said bend portion were not provided.

9. An easy opening container wall as defined in claim 8 wherein said container wall includes a depressed region for receiving said section of said tab prior to pivoting of the tab to form said opening.

10. An easy opening container wall as defined in claim 7 wherein said bend line forms an acute angle with the longitudinal axis of said tab, said preselected zone includes first and section portions extending in different directions and defining a corner of the wall segment, said tab having a rupturing nose adapted to contact said container wall substantially at said corner.

11. An easy opening container wall as defined in claim 10 wherein said wall segment includes a section outside of said depressed section, said tab being attached to the wall segment at said section which is outside of said depressed section.

12. An easy opening container wall comprising:

a container wall of sheet material, the sheet material of said container wall being weakened in a preselected zone to define a wall segment bendable inwardly of the container wall about a bend line;

a tab;

means for attaching the tab to the container wall, at least a portion of the tab overlying at least a portion of the wall segment, said tab being pivotable through a sufficient number of degrees to at least substantially invert said tab, such pivotal movement of the tab severing said sheet material along said preselected zone and bending the wall segment inwardly generally about said bend line to at least substantially invert the wall segment whereby an opening is formed in said container wall;

said tab when inverted projecting completely across said opening and having a section which overlies said container wall, said tab having a bend portion adjacent the rim of the opening when the tab is inverted which causes said section of said tab to be closer to the container wall than if said bend portion were not provided; and

said tab and said wall segment being sized and oriented so that a portion of said opening of sufficient size to constitute a pouring opening is uncovered by the tab when said tab and said wall segment are inverted.

13. An easy opening container wall as defined in claim 12 wherein said bend portion extends generally across said tab and provides a greater offset at one end of said bend portion than at the other end of said bend portion.

14. A method of providing an opening in a container wall comprising:

providing a container wall of sheet material having a weakened zone defining a wall segment bendable inwardly about a bend line and a tab attached to the container wall with at least a portion of a tab overlying at least a portion of the wall segment, the tab being pivotable generally about said bend line through about 180.degree.;

pivoting said tab generally about said bend line to rupture the sheet material of said container wall along said weakened zone to form an opening in said container wall;

continuing said step of pivoting to pivot said tab and said wall segment through approximately 180.degree. to thereby at least substantially invert said tab and said wall segment; and

the tab and the wall segment being sized and oriented so that a portion of said opening of sufficient size to constitute a pouring opening is uncovered after the tab and the wall segment are substantially inverted.