JPH01308744A - Easily opening can lid with inseparable tab - Google Patents

Abstract

PURPOSE:To intend a smooth can opening and reduction of a tamper resistance, by providing one or more recess or protrusion scores, having a specified inclination against a line which is connected by a curvature center of a weakened line and a neck center of a hinge near an attached tab, in a breaking part. CONSTITUTION:A lenear line I-I, is lined from a curvature center O of a weakened line 3 near point C to a center O' of the neck of hinge, the narrowest part MN. One or more recessed or protrusive score 10 having an inclination theta, of 80-100 deg. against said line I-I are provided in a breaking part 4. The chief purpose is to easily break the weaked line near the C point by the effective prevention from folding of the breaking part 4 into the can, making the line I-I as a ridge in the can opening process to break the weakened line 3 by push ing down the breaking part 4 with the tab edge 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a tab non-separable type easy-open can that has a structure in which the torn part is pushed into the can and the torn part and tab do not separate from the panel surface of the can lid. The present invention relates to lids, and particularly to improving the planar shape within the tear portion.

[Conventional technology]

In recent years, a non-separable tab method has been widely adopted as an easy-to-open lid for cans of beverages such as beer, juice, and coffee, in which the can can be opened without separating the tab (including the torn portion) from the can lid. This type of tab non-separation method can be said to be a superior can opening method compared to the conventional tab separation method in that it prevents environmental contamination or unexpected injury due to scattering of removed tabs.

However, this tab non-separable type can lid requires a force to open the can and is not easy to open, so it is necessary to increase the depth of the line of weakness to define the tearing part, which may cause accidental damage. If the can body is dropped, the torn part is likely to break, and furthermore, manufacturing control such as the depth of the line of weakness is complicated, making it difficult to mass-produce. There are also constraints in terms of material selection, as it is difficult to use inexpensive steel, and expensive aluminum must be used.

Here, Fig. 4 is a plan view illustrating an easy-open can lid of the tab non-separation type that is currently on the market, and Fig. 5 is a plan view illustrating the vicinity of the torn part in Fig. 4, excluding the tab. This is what I did.

In these figures, 1 is a can lid, 2 is a panel, and 3 is a line of weakness provided on the panel surface with a cross-sectional shape like an inverted trapezoid by press working. The weakened line 3 forms a substantially elliptical tear portion 4 having ends at points A and D near the center of the panel 2.

Further, near the center of the panel 2, a fixing portion 8 for the tab 5 is provided. Note that 9 is a tongue-shaped cut line provided on the tab 5, and 10 is a reinforcing bead for imparting rigidity to the tear portion 4.

To open such a can lid, first the rear end handle 6 of the tab 5 is opened.
Insert your finger under the tab and push it up, and use a lever with the fixed part 8 as a fulcrum to strongly press the torn part 4 through the tab tip 7 to point B on the line of weakness 3 near the tab fixed part 8. By breaking the vicinity and further pushing up the rear end handle part 6, the torn part 4 is removed.
is pressed down and the weakened line 3 is torn in both directions from point A, which is the starting end, to point C, which is the peripheral edge of the can lid, and the torn part 4 is folded down into the can. In this process, the crank introduced into the line of weakness 3 must change direction and rotate around point C, which is the longest distance from the tip of the tab, and therefore requires a large rank propagation force. Therefore, before the crank rotates around the vicinity of point C, the torn part 4 in contact with the tab tip 7 is locally folded into the can, making it impossible to open the can afterwards, or the tab 5
Various troubles may occur, such as the tab 5 being bent near the fixed portion 8, or the tab 5 coming off from the fixed portion 8.

Conventional techniques for improving these drawbacks include proposals such as U.S. Pat.

In the former case, as shown in FIGS. 6 to 8, the tab tip part has a two-stage structure consisting of an inner tip part 13 and a tip part 14 defined by the tab weakening line 11 and the tab cutting line 12, and the tab 5
In the can opening operation of pushing up the rear end handle 6, the line of weakness 3 is broken at the inner tip 13 of the tab, which has a similar shape to the line of weakness 3 near the tab fixing part 8, and then the line of weakness 3 is broken at the tearing part 4.
The line of weakness 3 is gradually torn by the upwardly thick (protruding tip 14). A notch 15 is provided in order to keep the can in a substantially perpendicular state to the panel portion 2 so that the can does not return together with the inner tip portion 13, that is, does not get in the way when eating or drinking the contents of the can. The tab weakening line 11 portion, which defines the two-stage structure of the tab tip, bends and deforms when the can is initially opened, pushing only the inner tip 13 into the can and breaking the weakening line near the tab fixing part 8. , in the middle stage of opening the can when the lines of weakness 3 are successively broken, the protruding end 14 effectively applies a pressing force to tear the line of weakness 3 near point C on the tearing part 4, and the tab 5 is returned to its original position. When the tab is returned to its original position, it must take on the critical role of causing bending deformation and retaining the tip end 14 of the tab within the can.Therefore, by overhanging the tip end 14 over the tear portion 4, the problem of the prior art is overcome. Although the purpose of the proposal to solve the problem is clear, the range of optimal conditions such as the depth of the tab weakening line 11 is extremely small.
Not only is mass production difficult, but a large amount of force is required to bend and deform the tab weakening line 11 when initially opening the can, making it impossible to open the can, or conversely causing the can to break at this location and the protruding end 14 to be damaged. There is also a risk of it getting mixed into the can.

The gist of the latter proposal in Japanese Patent Application Laid-Open No. 58-64945 is to provide a tab fixing portion 8 within the tearing portion 4, as shown in FIGS. 9 and 10. In other words, by pulling up the tab 5, the tearing part 4 is pulled up instead of being pushed down, and the weakened line 3 is sequentially torn to open the can.
After the can is opened, the torn part 4 and the tab 5 are placed in an inverted state on the panel surface.

In other words, the above-mentioned proposal is a completely new expansion force type that aims to change the idea of providing the tab fixing part 8 inside the tearing part, and it is a completely new expansion force type that aims to change the idea of providing the tab fixing part 8 inside the tearing part, and it is a completely new expansion force type that aims to change the idea of providing the tab fixing part 8 inside the tearing part. Problems such as the inability to continue operating the can or the bending of the tab 5 due to local bending are solved, but on the other hand, a large tear with a sharp edge appears on the panel surface where the drinking spout is located. It also has shortcomings.

[Problem to be solved by the invention]

As mentioned above, there is still no rational improvement measure for tab non-separable type easy-open can lids that is safe to handle, easy to open, not subject to restrictions on material selection, and easy to implement. Not proposed.

The present invention is intended to solve these problems, and in particular, it is an object of the present invention to present a solution to the problem regarding the openability of a tab non-separable type easy-open can lid.

[Means to solve the problem]

As a measure to solve these problems, the present inventor has studied in detail the bending deformation state of the tearing part 4 during can opening, and has developed a method for effectively concentrating the can opening force on the line of weakness 3 during the intermediate can opening process. found an effective means of imparting rigidity to the ruptured portion 4,
The present invention has now been constructed.

That is, the present invention has an approximately elliptical shape extending from near the center to the periphery of the can lid panel portion, and a discontinuous portion for forming a hinge portion near the center of the can lid. A tear defined by a line of weakness arranged so that the long axis of the can lid is in the radial direction of the can lid, and a tear defined by a line of weakness located outside the tear and near a discontinuous part of the line of weakness. In a tab non-separable type easy-open can lid to which a push-down tab is fixed, the center point of the curvature of the line of weakness near the periphery of the can lid panel on the long axis and the center of the neck of the hinge part near the tab fixed part To provide a tab non-separable type easy-open can lid, characterized in that one or more grooves or protrusions having an inclination angle of 80° to 100' with respect to the straight line connecting the points are provided in the tearing part. It is something to do.

In order to develop such a can lid, the present inventor prototyped this type of can lid using steel, which has never been used for can lids that are the object of the present invention. Various studies were conducted on the relationship between the bending deformation state of the part and the fracture form of the line of weakness.

As a result, in the conventional can lid illustrated in FIG. 4, in the can opening operation that causes the rear end handle 6 of the tab 5, the crank introduced into the line of weakness 3 rotates around the 0 point (FIG. 5). Since the torn part on the torn side folds into the can, the tab 5 moves to the can opening end position, that is, the position almost perpendicular to the panel surface 2, and subsequent can opening operations become impossible. I understand. That is, FIG. 11 is an external perspective view for explaining a state in which a steel can M1 (see FIG. 4) of a conventional design attached to a can body 16 is being opened. In the figure, it can be seen that although the tab 5 has been pulled up close to the can opening end position, the line of weakness 3 has been torn only to a point just short of the 0 point. As mentioned above, the reason for this is that the line of weakness 3 is torn and the torn part 4 in the area is locally folded into the can, and furthermore, the torn part 4 in contact with the tab tip 7, which is the point of action of the can-opening force. Due to buckling in the vicinity of point P of 4, the tab tip 7, which moves circumferentially before the crack goes around the 0 point, ends up losing its effective point of action on the rupture part 4. It is in.

In this way, the phenomenon in which it becomes difficult for the tab tip 7 to create an effective point of action can be solved by providing the tab fixing part 8 on the external panel surface 2 of the tearing part 4, that is, by providing the tearing part 4 as shown in FIG. This is a problem peculiar to can lids that are opened by folding them into the can, and a tab fixing part 8 as shown in FIG. It can be said that this is fundamentally different from the can lid which is opened by tearing up the lid.

Therefore, the inventor of the present invention has made it possible to continuously secure an effective point of action of the tab tip 7 on the tearing part 4, and to
We conducted various studies on effective means of imparting rigidity to the tearing part 4 to make it easier to concentrate the can opening force on the can opening, and developed a new can lid design that improves can opening performance as described above. It is something. The problem that the present invention aims at cannot be solved with the conventional technology is that it is based on the use of highly rigid aluminum ram as the can lid material. was the main focus. Therefore, if insufficient consideration is given to the bending deformation of the fractured part and steel is used as the material, inappropriate U
Convex or concave lines in the shape of letters have been frequently used as a preferred design.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a plan view showing an embodiment of the can lid according to the present invention;
2 is a plan view of the vicinity of the rupture portion in FIG. 1, and FIG. 3 is an enlarged cross-sectional view taken along the line II in FIG. 2.

In these figures, ■ is the can lid, 2 is the panel part, 3 is the weakened line, 4 is the torn part, 5 is the tab, 6 is the rear end handle of the tab,
7 is a tip of the tab, 8 is a fixed portion of the tab, 9 is a tongue-shaped cut, and 10 is a concave or convex line. Tab 5 is weak line 3
It is fixed to the outer panel part of the tearing part 4 near the discontinuous part by a method such as riveting or gluing.

In the can lid constructed in this manner, the present invention is characterized by the center point of the curvature of the line of weakness 3 near point C (hereinafter referred to as 0 point) and the center point of the neck of the hinge, that is, the most constricted part (hereinafter referred to as 0').
80° to 10 to the line Ii, which connects the points
One or more grooves or protrusions 10 having an inclination angle θ of 0° are provided in the tearing portion 4.

It is a feature of the present invention that such grooved or convex stripes are provided at an inclination angle, θ, of 80° to 100° with respect to the straight line connecting the 0' point and the 0 point, line I-1. This is an important component and its main purpose is to push down the tearing part 4 with the tip 7 of the tab and tearing the line of weakness 3 in the can opening process.
The purpose is to make it easier to tear the line of weakness near point C by effectively suppressing the tearing part 4 from folding into the can using the 1-■ line part as a ridge. If the inclination angle θ of these grooves or protrusions measured counterclockwise from the 1-1 line is less than 80° or more than 100", that is, if it deviates significantly from the right angle, the effect of suppressing the bending deformation of the torn part will be reduced. Otherwise, the effect of stress concentration on the line of weakness 3 near both ends of the groove etc. becomes smaller, making it difficult to obtain a satisfactory can-openability improvement effect.For these reasons, in the present invention, the inclination angle θ 80”～
100”.

These four stripes or convex stripes are provided for the purpose of suppressing the bending deformation of the tear portion 4 as described above and making it easier to concentrate stress on the line of weakness. It may be provided in either a convex shape 1 on the inner surface side, that is, a concave shape from the outer surface side, and the cross-sectional shape is not limited to the approximately arc shape shown in FIG. , an inverted trapezoid, or any other shape is acceptable.

In addition, the length, number, and spacing of these grooves can be changed as appropriate, but the length should be at least 273 or more than the distance between the weakened lines 3 located at both ends of the grooved lines, etc., and the length should be at least 273 or more than the distance between the weakened lines 3 located at both ends of the groove It is desirable to have the can opening force close to the line of weakness in order to concentrate it on the line of weakness.

〔Effect of the invention〕

As described above, according to the present invention, in the can opening process of pushing down the tearing part 4 with the tip 7 of the tab and tearing the line of weakness 3, the tearing part 4
is not locally folded into the can, making subsequent can opening operations impossible, and is weakened, making it easier to concentrate the can opening force on vI3, making the can opening operation smoother and reducing the can opening force.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a can lid illustrating an embodiment of the present invention, Fig. 2 is a plan view of the vicinity of the tearing part in Fig. 1, and Fig. 3 is an enlarged cross section taken along line I-1 in Fig. 2. 4 is a plan view illustrating a conventional can lid, FIG. 5 is a plan view near the tearing part in FIG. 4, and FIG. Fig. 7 is an enlarged plan view of the weakened line in Fig. 6, Fig. 8 is an enlarged side view of the tab tip of the can lid of Fig. 6 after opening, and Fig. 9 is an enlarged side view of the can lid of another prior art. The illustrated plan view, FIG. 10 is a plan view of the vicinity of the tearing part in FIG. 9, and FIG. 11 is an external perspective view for explaining the state of the can lid in FIG. 4 during opening. 1...can lid, 2...panel, 3...
・Weak line, 4...Tear part, 5...Tab,
6... Rear end handle portion of the tab, 7... Tip portion of the tab, 8... Fixed portion of the tab, 9... Tongue-shaped cut, 10... Concave or convex line, 11...・Tab weakening line, 12...cutting part, 13
... Inner tip of the tab, 14... Pronged end of the tab, 15... Notch, 16
...Can body.

Claims (1)

[Claims] The can lid panel has a substantially elliptical shape extending from near the center to the periphery, and a discontinuous portion for forming a hinge portion is provided near the center of the can lid, and the elliptical shape is A tear defined by a line of weakness with its long axis oriented in the radial direction of the can lid, and a tab for pushing down the tear on a panel portion outside the tear and near a discontinuous portion of the line of weakness. In the tab non-separable easy-open can lid to which the tab is fixed, connect the center point of the curvature of the line of weakness near the periphery of the can lid panel on the long axis and the center point of the neck of the hinge part close to the tab fixed part. A tab non-separable type easy-open can lid characterized in that one or more grooves or protrusions having an inclination angle of 80° to 100° with respect to a straight line are provided in the tear portion.