JP2609258B2 - Non-vent type full easy open can lid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a non-vent type full-easy open can lid which has improved tear opening by reducing the tearing force after initial can opening.

[Conventional technology]

The easy-open can lid can be opened by the pulling force of the fingertip without the need for a tool such as a can opener. Because of this convenience, it is currently frequently used for carbonated beverage cans, beer cans and the like. This easy-open can lid is classified into a partially open can (hereinafter, referred to as a partial easy-open can lid) that opens a part of the can lid and a full easy-open can lid that opens the can lid entirely. .

By pulling the pull knob fixed to the opening piece, the top of the pull piece on the pull knob side is pulled up and lifted, the opening is started, and the partial easy open can lid is further pulled by continuing to pull the pull knob. Complete the opening. On the other hand, in the full easy open can lid, the tip of the opening piece to which the pull knob is fixed is once bent inside the can body to start opening. Then, by pulling up the opening piece, the opening operation is continued, and the can is opened over the entire can body.

As described above, the format of the initial can is different between the partial easy open can lid and the full easy open can lid. Further, in the full easy open can lid, since the radius of curvature of the apex portion at the opening start side is larger than that of the partial easy open can lid, stress is less likely to concentrate at the start of can opening, and the initial can opening property is poor. Furthermore, since the opening piece of the full easy open can lid is larger than that of the partial easy open can lid, the tearing force after the initial can opening becomes extremely large.

For this reason, the full easy-open can lid has a poorer openability than the partial easy-open can lid.

Various studies have been made to improve the openability of the full easy open can lid. For example, by forming a destruction score on the line of the opening score carved in the periphery of the can lid, the remaining thickness of this portion is made smaller than the remaining thickness of the opening score, and This has been proposed in Japanese Utility Model Laid-Open No. 57-43239. In this way, by reducing a part of the opening score on the line, the initial openability is improved. In addition, JP
In -94291, the initial openability is improved by defining the distance between the nose and the closest opening score. On the other hand, without a vent score,
In the case of a non-vent type full-easy open can lid in which the opening score starts opening from the portion closest to the fixing portion of the pull knob, for example, Japanese Patent Laid-Open No. 54786/1979.
As proposed in the publication, it is proposed that an auxiliary score and a bead are provided along the inside of the opening score, and a discontinuous portion of the auxiliary score near the fixing portion is made longer than a discontinuous portion of the bead. ing. By providing such a bead, a large constriction is generated in the score for opening in the vicinity of the fixing portion, although it is useful to improve the openability, but the score for opening in the case of transport of the can body is broken. It is easy to occur. Further, when the can body falls for some reason, breakage is likely to occur.

By these means, it is easy to start the opening of the can lid when pulling the pull knob. But,
To reduce the tear force after the initial opening, no effective means has been proposed so far.

[Problems to be solved by the invention]

By the way, the ease and difficulty of opening when opening the easy-open can lid is determined by the initial opening ability at the start of opening, as well as the force required to tear the opening of the can lid from the can body. Is greatly affected by the size of For example,
Even if the initial opening property is excellent, if the tearing force is large, the shock or vibration when tearing the can lid is transmitted to the can body, and the contents may spill out. . Particularly, in the case of the full easy open can lid, since the opening piece separated from the can body is large, the tearing force is increased.

Therefore, an object of the present invention is to improve the openability of a full easy open can lid by reducing the tearing force.

[Means and actions for solving the problems]

Therefore, the present inventors divided the bending stiffness in the tearing direction of the opening piece into a strong portion and a weak portion in a non-vent type full easy open can lid, and further specified the position of this boundary portion to open the can. It has been found that the property is improved than before. Thereby, can openability can be improved without lowering the mechanical strength of the score for opening.

The full easy-open can lid of the present invention is formed by contrasting a pair of beads having a component along the tearing direction across the fixing portion of the pull knob, in order to locally add the strength of the rigidity. The angle [theta] formed by the tearing direction of the straight line l connecting the start end portion of the fixed portion and the tip end of the fixing portion is set to 45 degrees to 85 degrees. Here, the straight line 1 means a boundary line at a portion where the rigidity is strong and weak, and is a straight line connecting the front end 10 of the fixed portion and the start end 5a of the bead. At this time, the starting end of the bead may be provided anywhere on this straight line as long as it is inside the score for opening. As the length of the bead becomes longer, the opening piece opens deeper in the tearing direction at the initial opening, and at the time of tearing the opening piece subsequent to the initial opening, the length of the arm of the bending moment acting on the opening piece becomes larger, Although the tearing force after the initial opening decreases, the pushing depth of the opening piece at the initial opening also increases at the same time, which may damage the contents of the can. Therefore, in the present invention, while reducing the tearing force after the initial opening, it is a non-vent type full easy open can lid with good openability in consideration of not damaging the contents of the can. I do.

FIG. 1 shows an example of a full easy open can lid according to the present invention. An opening score 2 is engraved on the periphery of the can lid 1. In the vicinity of a part of the score 2 for opening, a fixing portion 4 in which a pull knob 3 is attached to the can lid 1 is formed. A pair of beads 5 are formed symmetrically on both sides of the fixing portion 4 with respect to an axis YY parallel to the tearing direction X. A straight line 1 connecting the starting end 5a of the bead 5 and the tip 10 of the fixing portion 4 is inclined at an angle θ with respect to the axis Y-Y.

Next, the operation until the can lid 1 is opened will be described. First, the opening is started at the initial opening start point 2a by putting a finger on the inside of the pull knob 3 to cause the opening, and the opening is gradually formed along the opening score 2 to near the intersection 2b of the straight line l and the opening score 2. Done. Further, when the pulling knob 3 is raised, the intersection 2b is moved to the intersection 2c.
The initial opening is completed by opening to the vicinity. Here, the intersection 2c is the intersection of the straight line m passing through the end 5b of the bead and the score 2 for opening, and is almost the end point of the initial opening. The can lid 1 in the initial opening is always pushed inside the can body and opened as shown in FIG. Therefore, the straight line m is a bent line of the opening piece 6 after the initial opening of the can. Subsequently, after the finger is re-hung on the outside of the pulling tab 3, the opening 6 is pulled up above the can lid 1, and when the opening 6 is torn, the length of the arm of the bending moment acting on the opening 6. , The tearing force after the initial opening can be significantly reduced.

In the present invention, it is important to specify the angle θ. Angle θ
However, as the size increases, the pull knob 3 is caused to cause a reduction in the force required during initial opening, particularly the force required for opening from the intersections 2b to 2c, but when the angle exceeds 85 degrees, the bead 5 is easily bent above the bead 5. The opening piece 6 at the initial opening.
The opening cannot be opened deeply in the tearing direction. Therefore, the length of the arm for giving a moment at the time of tearing cannot be secured, and the tearing force after the initial opening cannot be reduced. On the other hand, when the angle θ is less than 45 degrees, not only the force during the initial opening becomes large, but also the opening starting force at the point 2a becomes large. For this reason, the angle θ is specified to be 45 degrees to 85 degrees,
In order to reduce the opening start force, the force during the initial opening, and the tearing force after the initial opening in a well-balanced manner, it is preferable to set θ to 60 to 80 degrees.

In addition, if the pushing depth h of the opening piece 6 in the initial opening is large, the contents 9 of the can may be damaged depending on the contents at the time of the initial opening as shown in FIG. For example, if the contents of a can are fish or fruit,
In order not to damage this, the distance a in the tearing direction of the opening piece 6 between the end portion 5b of the bead and the center of the fixing portion 4 is set to 25 mm or less,
It is preferable to reduce the indentation depth h. On the other hand, the indentation depth h is like powder or liquid such as laver or powdered milk.
If the contents are not damaged even if the size is large, the tearing force after the initial opening decreases as the arm length of the bending moment increases, so the distance a is scored from more than 25 mm. It can be up to the vicinity of the final opening. As for the lower limit of the distance a, it is preferable that the lower limit be one or more times the diameter of the fixing portion or 4 mm or more whichever is longer in order to secure the length of the arm for generating a bending moment at the time of tearing.

Therefore, a non-vented full easy-open can lid having good openability in consideration of the contents of the can as well as lowering the tearing force of the initial opening.

In addition, this bead 5 is, as shown in FIG.
It can be inclined at an angle α with respect to Y. Bead 5
Is maximum when the direction of the bead 5 is the same as the tearing direction X, but if the angle α is within ± 30 degrees, the opening piece 6 is unlikely to be bent in the middle of the bead 5. However, when the angle α is more negative than −10 degrees, the bead 5 approaches the fixing portion 4, for example, the rivet, which hinders rivet processing. Therefore, it is preferable that the angle α of the bead 5 is -10 degrees to 30 degrees. However, the fact that the angle α is minus means that the interval between the beads 5 is in the tearing direction X.
Indicates a state of being stuck along the angle, and conversely, the angle α
Is positive indicates that the bead 5 is flared.

Further, an auxiliary score 8 may be provided on the can lid 1 along the score 2 for opening.

Further, the full easy-open can lid of the present invention can be applied to a safety-type can lid in which the cut end of the can and the opened piece are not injured.

The material to which the full easy open can lid of the present invention is applied need not be specified. For example, the following materials are used in addition to commonly used tin materials and aluminum plates.

(1) Non-ferrous metal materials represented by iron and iron alloys or aluminum and aluminum alloys.

(2) A metal material obtained by subjecting the metal material of (1) to a surface treatment such as plating or painting.

(3) A composite metal material in which an organic material such as a resin is joined to the metal material of (1) and (2) in a layered manner.

(4) A composite metal material in which the dissimilar metal materials of (1) and (2) are connected in layers.

〔Example〕

As the can lid 1, a T-4 tin plate having a thickness of 0.23 mm was used, and the remaining score of the opening score 2 was 50 μm.
Manufacture of type 1 (3 1/16 inch) full easy open can lids, tearing force and indentation depth h after initial can opening
Table 1 shows the measurement results. In the same table, a conventional full easy open can lid having no bead is shown as a comparative example. On the other hand, Examples 1 to 4 are full easy-open can lids having the shape shown in FIG.

As is clear from Table 1, in Examples 1, 2, 3 and 4 in which beads were provided, the tearing force after the initial opening was lower than in the comparative example. This indicates that the can can be easily opened without applying great force to the can lid. Examples
The pushing depths h of 1, 2 and 4 are almost the same as those of the prior art and do not damage the contents.

〔The invention's effect〕

As described above, the non-vented full easy open can lid of the present invention reduces the can opening force after the initial opening by increasing the rigidity of the opening piece by providing a bead defining the position of the starting end. Further, by defining the end position of the bead, it is possible to obtain a can lid having excellent can opening properties in consideration of not damaging the contents of the can.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a full easy-open can lid according to the present invention, FIG. 2 shows how contents are damaged at the time of opening, and FIG. 3 explains the angle α.

Continuation of the front page (72) Inventor Shinji Tanimoto 1-1-1, Edamitsu, Yawatahigashi-ku, Kitakyushu-shi, Fukuoka Prefecture Inside Nippon Steel Corporation Yawata Works (56) References JP-A-49-8382 (JP, A) JP-A-50-27681 (JP, A)

Claims (2)

(57) [Claims] 1. An opening score is engraved around the can lid.
A pair of beads having a component along the tearing direction are formed symmetrically on both sides of the fixing portion of the pull knob provided near the opening score, and a straight line connecting the starting end of the bead and the tip of the fixing portion. Angle to the tearing direction between 45 and 85 degrees
By inclining between degrees, and by making the opening piece tearing direction distance between the bead end portion and the center of the fixing portion 25 mm or less, a can lid for contents that is damaged when the pushing depth of the opening piece is large is obtained. A non-vent type full easy open can lid with excellent openability. 2. An opening score is engraved around the can lid.
A pair of beads having a component along the tearing direction are formed symmetrically on both sides of the fixing portion of the pull knob provided near the opening score, and a straight line connecting the starting end of the bead and the tip of the fixing portion. Angle to the tearing direction between 45 and 85 degrees
By inclining between degrees and setting the distance between the end of the bead and the center of the fixed part to tear in the direction of the opening piece from more than 25 mm to the vicinity of the score final opening, even if the pushing depth of the opening piece is large, it is damaged. A non-vent type full easy-open can lid with excellent openability, characterized by being used as a can lid for contents.