Easy Opening Device In A Container Wall

Abstract

An easy opening device is provided in a container wall including a score line in the container wall defining a panel which is at least partially severable from the wall and a tab with a nose end overlying the container wall and affixed to the removable panel near its starting end and a handle end toward the opposite edge of the container wall, and which further includes a tear strip defined by a U-shaped score with its open end toward the starting end of the removable panel and the handle end of the tab attached to the starting end of the tear strip.

Description

BACKGROUND OF THE INVENTION

It is known to provide easy opening devices with pull tabs thereon which remain attached to a container wall after opening in order to reduce litter problems which may be caused by small tabs which are carelessly discarded. For example. U.S. Pat. No. 3,618,815 illustrates and describes an easy opening device comprising a V-shaped opening flap in a container wall and a tab attached to the opening flap for plunging the flap into a container on which the container wall is attached. The tab on the easy opening device disclosed in the patent has a nose end and a handle end with a weakening line therebetween so that, after opening, the handle end of the tab can be depressed to a nonobstructing position on the container wall without closing the pouring orifice which has been formed. Such easy opening device also includes a tear strip in the container wall adjacent the opening flap and attached to the handle end of the tab for providing a vent opening in the container wall. This tear strip is completely severed from the container. The patent discloses no connection of the handle end of the tab to the container wall for controlling bending of the opening flap during opening.

SUMMARY OF THE INVENTION

This invention provides an improvement for an easy opening device such as that which is illustrated and described in U.S. Pat. No. 3,618,815, which improvement comprises means attached to the handle end of a tab and to a container wall for controlling bending of the tear panel in the container wall during opening. In a preferred embodiment of the invention, such bend control means comprises a U-shaped tear strip in a container wall having its open end toward an opening flap and its closed end attached to the handle end of a tab.

Accordingly, an object of the invention is to provide an easy opening device which includes means for controlling bending of a removable panel portion during opening.

Another object of the invention is to provide an improved easy opening device which remains attached to the can end after opening.

A further object of the invention is to provide a non-removable easy opening device which forms a relatively large pouring orifice and a small vent opening in a can end.

Another object of the invention is to provide means in an easy opening device with a tab thereon which can be lifted to open a container wall with a minimum of force while plunging a relatively large portion of the container wall downward into a container.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the invention will be more fully understood and appreciated with reference to the following description and the drawings appended hereto wherein:

FIG. 1 is a top plan view of a container wall of the invention prior to attachment of a tab to the end;

FIG. 2 is a bottom plan view of a tab for attachment to the container wall of FIG. 1;

FIG. 3 is a top plan view of the container wall of FIG. 1 after attachment of the pull tab of FIG. 2 to the end;

FIG. 4 is a cross-sectional view of a container wall of the invention affixed to a container;

FIG. 5 is a cross-sectional view similar to FIG. 4 and further illustrating initiation of opening;

FIG. 6 is a cross-sectional view similar to FIG. 4 and further illustrating initiation of rupture of an opening flap in the container wall;

FIG. 7 is a cross-sectional view similar to FIGS. 4-6 and further illustrating completion of the lifting portion of the opening sequence; and

FIG. 8 is a cross-sectional view similar to FIGS. 4-7 and further illustrating the handle end of the tab depressed to a non-obstructing position on the container wall.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, a sheet metal container end wall 10 for a can or other container is illustrated before a tab is attached to the end. Preferably, can end 10 is made of aluminum or an alloy thereof, although it can also be made of other metals or plastic materials. Wall 10 may have peripheral seam 14 therearound for joining it to a container body by conventional methods, and may have a peripheral groove 16 adjacent seam 14 to strengthen the end against reversal or outward doming. To provide a pouring orifice in the can end, a V-shaped score line 18 may be formed in the wall 10 to define a flap 20 which can be depressed into a can to which the end wall is affixed. A rounded apex 22 of flap 20 is located adjacent the periphery of wall 10 to provide a starting end on the flap, and the ends of score 18 extend outwardly from the apex at an angle of approximately 60.degree. to locations approximately one-third of the distance across the end wall so that a relatively large pouring orifice can be formed. An anti-fracture score 24 may also be provided in opening flap 20 adjacent and parallel to score 18 as is well known in the art.

It is a feature of this invention that container wall 10 includes a U-shaped score 26 defining a tear strip 28 which is only partially severable from the container end. Previously known container walls, as exemplified by the container wall described in U.S. Pat. No. 3,618,815, have included a second score line defining vent opening which was completely removed from a container wall rather than only partially severable as in the present invention. By providing a tear strip which is only partially severable, the present invention provides a permanent connection between container wall 10 and handle end 44 of tab 40 which controls bending of opening flap 20 along a predetermined line. The location of such a predetermined bend line is generally dependent on the location of the connection of tear strip 28 to container wall 10. By locating the furtherest outward extent of score 26 on or near a line drawn through the ends of score 18, the predetermined bend line will occur near the base of opening flap 20 defined by score 18. So locating the bend line means that a relatively large pouring orifice will be formed in container wall 10 as will be described. As illustrated, the ends of score 26 may have an outwardly curved tail of approximately 180.degree. to resist accidental severance of tear strip 28 from end wall 10.

Container wall 10 further includes two integral upstanding hollow rivets 30 and 32, one in the starting end of opening flap 20 and one in the starting end of tear strip 28 for attachment of a tab to the opening flap and the tear strip. Rivet 30 in opening flap 20 is preferably located near the apex 22 of the flap in order to facilitate initiation of rupture of score 18 around such apex. U-shaped score 26 may be formed closely adjacent the base of rivet 32 and preferably in the area around the base of the rivet which was worked during forming of the rivet. This is intended to reduce the force which is required to rupture such score as is well known in the art.

It is another feature of the invention that container end wall 10 includes two downwardly embossed ribs 34 in opening flap 20 which help to control bending of the opening flap along a line drawn through the outermost extent of score 26 in the end wall. Ribs 34 are preferably substantially parallel to score line 18 along opposite sides of flap 20 and extend from approximately the desired line of bending of the flap toward the apex of the flap. The ends of ribs 34 toward the center of container wall 10 are preferably located approximately equal distance between the ends of score 18 and score 26 so that flap 20 is reinforced centrally between the end of such scores. The function of ribs 34 will be further explained in the description of the opening of a container end of the invention.

Container end 10 may further include an upwardly projecting embossed hook formed therein for restraining handle end 44 of tab 40 against the container wall after the tab has been manipulated to open flap 20. An embossed hook of this type and a method of forming the same are illustrated and described in application Ser. No. 212,562, filed concurrently herewith on Dec. 27, 1971. Embossed hook 36 may be formed in a variety of locations but is preferably located on end wall 10 so that it can be hooked over a bead around an aperture in the handle end of a tab to restrain such handle end against the end wall of the container end. This will be more fully understood and appreciated with reference to FIGS. 3 and 7, and the description of such figures. Container wall 10 may further include an embossed depression or finger well 38 in the container wall under handle end 44 of tab 40 (FIGS. 2 and 3) which is hereinafter described to facilitate gripping such a tab.

Turning to FIG. 2, a tab 40 is illustrated for attachment to a container wall 10. Tab 40 may be formed from sheet metal, preferably aluminum or an alloy thereof, and has a triangular shaped nose end 42 and a handle end 44 with a large aperture therein to facilitate gripping by a user. Referring further to FIGS. 3 et.seq., tab 40 has a substantially planar upper wall with two downwardly embossed wells 46 and 48 therein and with apertures in the bottom of the wells for receiving integral rivets 30 and 32 for attachment of the tab to container wall 10. To strengthen tab 40 and avoid sharp edges, the sheet metal of the tab may be curled downwardly and inwardly around the large finger aperture in the handle end of the tab and along the outer edges of the tab to form beads 50 and 52 respectively. Nose end 42 of tab 40 may also be reinforced by means of the downwardly directed flange 54 which may have a point 56 on the end of the tab nose to facilitate rupture of the score line at the starting end of opening flap 20 in the can end.

Re-entrant flanges 58 are preferably provided on the bottom of tab 40 intermediate bead 50 and flange 54 along both sides of the tab to provide hinge elements on the tab as will be described. Re-entrant flanges 58 may be substantially parallel to the upper wall of the tab and are directed inwardly toward the longitudinal axis of the tab. Except for these flanges 58, tab 40 is weakened along line 60 between nose end 42 and handle end 44 so that the handle end of the tab can be depressed to a non-obstructing position on a can end after opening. This weakening may be in the form of a cut through the sheet metal of the tab along line 60. Uncut flanges 58 provide ligaments of metal for maintaining tab 40 substantially rigid during lifting, and thereafter form bendable hinge elements for depressing handle end 44 of tab 40 to a non-obstructing position on a can end after opening. The sheet metal in flanges 58 preferably lies substantially parallel to the plane of tab 40 and to a container end upon attachment of the tab thereto to permit relatively easy bending of the flanges and the tab in a downward direction, but provide adequate strength to resist bending of the tab in an upward direction.

FIG. 3 illustrates a tab 40 attached to a container end 10 by means of two integral rivets 30 and 32. As attached, nose end 42 of tab 40 overlies opening flap 20, and handle end 44 of the tab overlies tear strip 28 toward the opposite side of the container end. The outer end of handle end 44 is disposed over finger well or depression 38 in container end 10 so that a user can more easily grip the handle end of the tab. Lock-down hook 36, which is upwardly embossed in wall 10, is disposed within the large finger aperture in handle end 44 of the tab closely adjacent the bead around the inside of the finger aperture. As will be explained, the purpose of lock-down hook 36 is to engage handle end 44 of the tab 40 subsequent to opening of the opening flap so that the handle end of the tab will be held in non-obstructing position on the can end during emptying. Lock-down hook 36 preferably does not engage the bead around the finger aperture in the tab prior to opening of opening flap 20 so as to avoid restraint against initially lifting the tab to open flap 20.

FIGS. 4-8 illustrate plunging of opening flap 20 into container 62 and depression of handle end 44 of tab 40 downward to a non-obstructing position on container wall 10. It is seen in FIG. 4 that initial lifting of handle end 44 of tab 40 exerts an upward force on rivet 32 to rupture score line 26 around tear strip 28 to partially sever the tear strip from the end. This forms a vent in container wall 10 to permit pressurized gases to escape from the can upon opening, and also permits air to enter the can during emptying. Since the vent is located under tab 40, the vent opening is shielded by the tab and accidental spraying of the contents of the can on the user during opening is substantially prevented.

Since tab 40 is connected to flap 20 near the apex or starting end of the flap, rupture of score line 18 around tear strip 28 permits a substantial length of the tab to be raised slightly above the surface of end wall 10 as illustrated in FIG. 5. This facilitates griping of tab 40 for application of force against the starting end of flap 20 by the nose of the tab to initiate rupture of score line 18. This initial lifting of tab 40 may be, in part, further facilitated by upward doming or flexing of end wall 10. Unless tab 40 can be lifted off the surface of end wall 10 to facilitate gripping its handle end, initiation of rupture of score 18 may be difficult. With the prior end wall structures such as that illustrated and described in U.S. Pat. No. 3,618,815, the rivet connection was located a substantial distance from the starting end of the opening flap (closer to the bend line) and prevented lifting of the handle end of the tab prior to initiation of rupture of the score line around the starting end of the tab. Prior end wall structures of this type were therefore substantially more difficult to open than are easy opening devices of the present invention.

As illustrated in FIG. 6, end wall 10 of this invention is unique in that tear strip 28 remains attached to can end 10 as opening flap 20 is plunged into a can. Tear strip 28 thereby provides a connection between handle end 44 of the tab 40 and container end 10 and, as discussed above, forces bending of the opening flap to occur along a predetermined line. The outermost extent of score 26 establishes the predetermined line of bending of flap 20. This line may or may not be located approximately on a line through the ends of score line 18. FIGS. 5 and 6 show a three bar linkage which it is believed is formed by tear strip 28, tab 40 between rivet attachments 30 and 32, and opening flap 20 between rivet attachment 30 and tear strip 28. Since tab 40 remains substantially rigid during lifting and since tear strip 28 and flap 20 are attached to end wall 10 on substantially a common line after score line 18 is initially ruptured, bending is effected substantially along the line of attachment. Continued lifting of tab 40 therefore plunges the entire opening flap 20 into container 62 as illustrated in FIG. 7. Since bending has been controlled to occur along the desired predetermined line, a relatively large pouring orifice is formed in container wall 12. Although FIG. 7 does not so illustrate, tab 40 is preferably rotated until it contacts seam 14 to insure that flap 20 will not obstruct the pouring orifice after opening, and to insure that handle end 44 of the tab can be locked down after opening as will be explained.

Embossed ribs 34 in flap 20 provide reinforcing means in the flap to resist bending of the flap at an angle with respect to a line through the ends of score 18. In the absence of such ribs 34, flap 20 could bend on an oblique angle to the axis of tab 40 if a lifting force is applied to one side of the longitudinal centerline of the tab. Such a force application tends to twist tab 40 and flap 20 attached thereto to effect rupture of one leg of score line 18 along its entire length and rupture of the other leg along only a portion of its length. With embossed ribs 34 in flap 20, the flap is substantially rigid along the length of the ribs so that twisting of the flap which can cause bending of the flap on an oblique angle is resited. Accordingly, ribs 34 insure opening the full extent of flap 20 to provide a relatively large opening in container wall 10.

After a pouring orifice and vent opening have been formed, it is next desired to move handle end 44 of tab 40 to a position in which it will not interfere with pouring or drinking from a can. This is done by pushing handle end 44 downward against end wall 10 as shown in FIG. 8. For this purpose, end wall 10 is designed so that flap 20 is stronger or more unyielding against bending than is tab 40. As described above, tab 40 is easily bendable about cut line 60 when handle end 44 of the tab is depressed. Flanges 58 on the undersurface of the tab provide relatively thin sections of metal which are easily bent to depress the tab to a nonobstructing position. Tab 40 bends or folds along cut line 60 between its handle end and its nose end, and flap 20 remains depressed in the end rather than hinge upwardly to again fill the pouring orifice in the end.

As more fully illustrated and described in application Ser. No. 212,562, filed concurrently herewith, a lock-down hook 36 on end wall 10 engages bead 52 around the inside of the finger aperture in the handle end 44 of tab 40 to hold such handle end on the container end when the handle end is depressed to a non-obstructing position. In the absence of such a lock-down hook, spring back of handle end 44 of tab 40 could result in the handle end of the tab becoming raised above the surface of container wall 10. If this were to happen, the handle end of the tab could interfere with drinking through the pouring orifice in the container end. As mentioned above, it is recommended that tab 40 be rotated against seam 14 during opening in order to assure that handle end 44 of the tab can be locked down by hook 36. This rotation of tab 40 plunges nose end 42 of the tab as far as possible into a can to move handle end 44 forward on end wall 10 so that lock-down hook 36 will engage an edge of the handle end of the tab when it is depressed against the end wall.

It is therefore seen that in accordance with the invention an integral easy opening device is provided on a can end whereby, after opening has been effected by lifting the tab, the tab can be depressed to a non-obstructing position and remains on the can end. Although a particular embodiment of the invention has been illustrated and described, it will be apparent to those skilled in the art that numerous variations can be made in the details of the invention without departing from the invention.

Claims

What is claimed is:

1. In an easy opening device in a container wall comprising a score line in the container wall defining a panel which is at least partially severable from the container wall and having a starting end adjacent the periphery of the container wall and a tab attached to the starting end of the panel, the improvement comprising a second score line in the container wall defining a tear strip having a starting end toward the center of the container wall and a terminal unscored end toward the starting end of said removable panel, said tab being attached to said tear strip near its starting end, said second score line being adapted to be ruptured upon lifting of the tab, and said tear strip remains attached to the container wall to control bending of said removable panel during opening.

2. An easy opening device as set forth in claim 1 in which the score line defining said panel is substantially V-shaped toward one edge of the container wall and said second score defining a tear strip is substantially U-shaped and the ends of both score lines are located closely adjacent a common line.

3. An easy opening device as set forth in claim 2 which includes embossed ribs in said panel aligned substantially parallel to opposite edges of the panel.

4. An easy opening device as set forth in claim 3 in which said tab includes a nose end overlying the panel and a handle end overlying said tear strip and a weakening line in the upper portions of the tab between said nose end and said handle end.

5. An easy opening device as set forth in claim 4 in which said tab has downwardly formed wells therein and apertures in the bottoms of the wells through which the tab is attached to the panel and tear strip.

6. An easy opening device as set forth in claim 1 in which said tab is made of sheet metal and has reinforced portions along at least its longitudinal edges.

7. In an easy opening device in a container wall including a score line therein defining a panel which is at least partially severable from the wall with a starting end thereof adjacent one edge of container wall, said device further including a tab having a nose end overlying the starting end of the severable panel and affixed thereto, and a handle end toward an opposite edge of the container wall, the improvement comprising:

connecting means attached to the handle end of the tab and extending therefrom toward the starting end of the severable panel to a permanent attachment of the connecting means to the container wall at a location short of the attachment of the nose end of the tab to the starting end of the panel, said connecting means being adapted to control bending of said panel during opening.

8. An easy opening device as set forth in claim 7 in which said connecting means comprises a U-shaped tear strip in the container with its open end toward said starting end of said panel and its closed end attached to the handle end of the tab.

9. An easy opening device as set forth in claim 7 in which said panel is defined by a substantially V-shaped score having its apex adjacent one edge of the container wall.

10. An easy opening device as set forth in claim 9 which includes embossed ribs in the opening flap aligned substantially parallel to opposite edges of the opening flap.

11. An easy opening device as set forth in claim 7 which includes an embossed depression in the end wall under the outer end of the handle end of the tab.