JP2002234535A - Cap of can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap of a can capable of preventing the can from being opened when a shock is given to the can. SOLUTION: A plurality of concave portions 30 (easily protrudable portions) sinking not less than 0.3 mm in depth toward the reverse side is formed on an area of a surface of a cap 14 of a can having an openable portion 20 formed by a weakened line 18, the area being in the vicinity of an outer circumferential margin opposite to an openable portion 20 with respect to the center P of the cap 14 of the can within the central angle of 90 degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a can lid used for a can used as a container for soft drinks and the like.

[0002]

2. Description of the Related Art Conventionally, as a can lid of this type, for example, FIG.
The following are known. In the can lid 2, a substantially fan-shaped openable portion 8 extending from the center to the peripheral portion is defined by a weakened line 6 in a substantially dish-shaped can lid main body 4, and an end of the openable portion 8 and a pull-off tab 10 Are connected by a rivet portion 12.

The can lid 2 is attached so as to cover an upper part of a cylindrical can body having a bottom and is used for sealing a liquid such as a soft drink inside.

[0004]

By the way, a can sealed with a liquid inside as described above is dropped on the floor,
Further, during transportation, a strong impact may be applied to the can. In such a case, the inside of the can becomes extremely high instantaneously, and after repeating this several times, the can lid rises to the outside by this pressure, whereby the openable portion 8 is opened and removed from the can. There is a risk that the contents of the can may be lost or may fall out.

The present invention has been made under the above background, and has as its object to provide a can lid capable of preventing the can from being opened when an impact is applied to the can.

[0006]

According to the present invention, there is provided a can lid having an openable portion formed by a weakening line, the surface of the can lid being opposite to the center of the can lid and opposite to the openable portion. A plurality of easy protruding portions that protrude when the pressure in the can rises are formed in the vicinity of the outer peripheral edge and within a range where the central angle is within 90 degrees. Further, it is desirable that the easily protruding portion is constituted by a concave portion which is depressed to a depth of 0.3 mm or more toward the back side of the can lid. The present invention is particularly suitable for a can lid provided with a stay tab.

[0007] In the can lid according to the above configuration, when pressure is applied from the back side, before the vicinity of the openable portion rises, the vicinity of the easily protruding portion such as a recess having a low pressure resistance is outside (front side). And the pressure rise in the can is suppressed.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view showing a can lid according to one embodiment of the present invention. The can lid 14 shown in the same figure also has a substantially sectorial shape from the center to the peripheral edge by a weakening line 18 on a substantially dish-shaped can lid body 16 similarly to the conventional can lid 2 shown in FIG. An openable portion 20 is defined, and an end of the openable portion 20 and a pull-off tab 22 are connected by a rivet portion 24. Reference numeral 26 denotes a projection provided to prevent bending of the can lid 14 when the can is opened.

In this embodiment, the can lid 14 is a
6, a plurality of hemispherical recesses (easy protruding portions) 30 formed by being depressed toward the back surface side.
The depth d of the concave portion 30 is formed to be 0.3 mm or more. As shown in FIG. 1, the concave portion 30 is located on the opposite side of the openable portion 20 with respect to the center P of the can lid body 16 and has a central angle within 90 degrees (hereinafter, this range is referred to as “safety”). And is formed along the outer peripheral edge of the can lid body 16 and in the vicinity thereof.

The can lid 14 is attached so as to cover the upper part of a cylindrical can body having a bottom as in the case of the conventional can lid 2 shown in FIG. Used to seal

In the can lid 14 configured as described above, if the can is dropped on the floor or a strong impact is applied to the can at the time of transportation, the can lid 14 is viewed from the back side of the can lid 14. Strong pressure acts on the surface side. At this time, the recess 30
Since the pressure-resistant strength is low, the recess 30 before the entire can lid body 16 rises (so-called buckling).
The vicinity protrudes to the surface side. As a result, it is possible to suppress a rise in the pressure inside the can and to know that the pressure inside the can is rising. Therefore, by detecting the protrusion in the vicinity of the concave portion 30, it is possible to prevent the openable portion 20 from being detached from the can or the contents of the can from leaking.

The reason why the depth d of the concave portion 30 is set to 0.3 mm or more is that if the depth d is less than this, the effect of suppressing the pressure increase in the can becomes insufficient. If the depth d is increased, the in-can pressure when the recess 30 projects (hereinafter, referred to as “projection pressure”) decreases, and if the depth d is reduced, the projection pressure can be increased. Therefore, it is desirable to appropriately adjust the depth d according to the pressure resistance of the openable portion 20 within a range where the protruding pressure does not exceed the pressure that the openable portion 20 can withstand.

The reason why the concave portion 30 is formed in the safe range is that if the concave portion is formed in a portion outside the safe range of the can lid body 16 when the inside of the can reaches the protruding pressure and the concave portion protrudes. In this case, the periphery of the concave portion rises, and at this time, the vicinity of the openable portion 20 also rises, and a shearing force is applied to the weakened line portion. This is because there is a danger that they will be lost.

In the above embodiment, the concave portion 30 is formed near the outer peripheral edge of the can lid body 16. However, the concave portion is formed near the outer peripheral edge having high rigidity, so that the concave portion can be easily projected. To do that.

The shape of the recess formed on the surface of the can lid body 16 is not limited to the shape of the above embodiment.

In the above-described example, an example is shown in which the present invention is applied to a can lid provided with a pull-off tab which is opened at the surface side of the can lid when the can is opened and is separated from the can lid.
The present invention is not limited to a can lid fitted with a pull-off tab. FIG. 2 shows an example in which the present invention is applied to a can lid to which a stay-on tab is attached, in which the tab does not separate from the can body when the can is opened. In the can lid 32 shown in this figure, an openable portion 38 is defined in a can lid body 34 by a weakening line 36, and an end of the openable portion 38 and a stay tab 40.
Are connected by a rivet section 42. On the surface of the can lid body 34, two oval concave portions (easy protruding portions) 44 having a depth of 0.3 mm or more are formed in a safe range.

When the recess 44 is formed in the can lid 32 on which the stay tab 40 is mounted as described above, when the pressure in the can rises, it is necessary to prevent the openable portion 38 from being turned up to the front side and opening. In addition to being able to prevent the opening, the periphery of the openable portion 38 can be prevented from being turned outward, so that a person raises the finger hooking end 40a of the stay-on tab 40 to open the can and moves the openable portion 38 inward. Does not occur when the opening portion 38 does not enter the inside.

[0018]

As described above, according to the present invention, on the surface of the can lid, a plurality of easy protruding portions such as recesses formed by depressing a depth of 0.3 mm or more toward the back side are formed. Therefore, when an impact is applied to a can using this can lid, the area near the easy protruding part expands outward, and the entire can lid does not rise outward, so the openable part is opened and removed from the can. There is no danger that the contents of the can will fall out.
In addition, since the easily protruding portion is formed on the opposite side of the openable portion with respect to the center of the can lid and in a range where the central angle is within 90 degrees, even if the vicinity of the easily protruding portion rises outward, the easily protruding portion can be opened. The neighborhood does not swell. In addition, since this easily protruding portion is formed near the outer peripheral edge of the highly rigid can lid,
The easily protruding portion can be easily protruded.

[Brief description of the drawings]

FIG. 1 is a plan view of a can lid according to one embodiment of the present invention.

FIG. 2 is a plan view of a can lid according to another embodiment of the present invention.

FIG. 3 is a plan view showing a conventional can lid.

[Explanation of symbols]

 14, 32 can lid 18, 36 weakening line 20, 38 openable part 30, 44 recess (easy protruding part)

Claims (3)

[Claims] 1. A can lid having an openable portion formed by a line of weakness, wherein the surface of the can lid is near an outer peripheral edge of the surface of the can lid opposite to the openable portion, and A can lid characterized by forming a plurality of easy protruding portions that protrude when the pressure inside the can rises within a range of a central angle of 90 degrees or less. 2. The can lid according to claim 1, wherein said easy protruding portion comprises a concave portion which is depressed by a depth of 0.3 mm or more toward the back side of said can lid. 3. The can lid according to claim 1, further comprising a stay tab.