JPH0920334A - Lid of can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of thin swarf that is generated when a lock seam roller is brought in contact with the edge of a curled part of a lid of can during double lock seam process. SOLUTION: The thickness of a curled part 1a of a lid of a can is tapered off toward the edge so that the edge of the curled part 1a is easily bent when the edge of the curled part 1a comes in contact with a groove of the lock seam roller and the curved middle part of the curled part 1a comes into contact with the lock seam roller instead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can lid, and particularly to a can lid that is effective when it is double-wound around a can body to seal the inside of the can.

[0002]

2. Description of the Related Art A process of double-tightening a can lid around a can body to seal the inside of the can will be described with reference to FIGS. As shown in FIG. 6, a can body 32 having a can lid 31 placed thereon with a drink or the like placed thereon is placed on the lifter base 21, and the lifter base 21 is raised to engage the can lid 11 with the chuck 22. Further, the lifter base 21 is raised to apply a compressive load between the can lid 31 and the can body 32, and then the chuck 22 and the like are rotated to rotate the can lid 31 and the can body 32.

Next, the roll 23 is moved so that the groove portion 23a of the rotatably supported first winding roll 23 approaches the peripheral edge of the can lid 11 (FIG. 7A), and the roll 2
Curl portion 3 which is the peripheral portion of can lid 31 in groove portion 23a of
1a is inserted (FIG. 7 (b)) and the roll 23 is attached to the can lid 3
1 and the curl portion 3 by moving to the center of rotation of the can body 32.
By bending 1a (FIG. 7C) and further moving the roll 23 to wind the curl portion 31a of the can lid 31 inside the flange portion 32a of the can barrel 32 (FIG. 7D),
Tighten the first winding.

After the completion of the first winding, the first winding roll 23
6 is moved so as to be separated from the can lid 31 and the can body 32, and then the second winding roll 24 shown in FIG.
The second winding is performed by pressing the peripheral portion of the can 2 and the above-mentioned winding portion so that the curl portion 31a of the can lid 31 and the flange portion 32a of the can body 32 are brought into close contact with each other. Thus, the inside of the can is completely sealed by double-winding the curl portion 31a of the can lid 31 and the flange portion 32a of the can body 32.

[0005]

When the can lid 31 and the can body 32 are wound and fastened as described above, the first winding roll 23 is rotated at a rotational speed of the can lid 31 due to frictional resistance of the shaft supporting portion. Since the rotation speed is slightly slower, the curl portion 31a of the can lid 31 and the groove portion 2 of the first winding roll 23
Slip will be generated between 3a and 3a. If such a slip occurs, when the edge of the curl portion 31a of the can lid 31 and the groove portion 23a of the first winding roll 23 come into contact with each other, as shown in FIG. There is a possibility that a cutting action will occur in the contact portion and thin chips will be generated from the contact portion.

When the thin chips as described above are generated, there is a possibility that the thin chips may get into the can, which is a problem.

[0007]

In order to solve the above-mentioned problems, a can lid according to the present invention is characterized by having a peripheral edge portion whose wall thickness becomes thinner toward the edge.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a can lid according to the present invention will be described with reference to FIGS. 1 is a sectional view of the can lid, FIG. 2 is an enlarged view of an arrow II in FIG. 1, and FIG. 3 is a sectional view showing a structure of a mold used for manufacturing the can lid. FIG. 4 is an enlarged view of an arrow IV in FIG. 3, and FIG.
It is explanatory drawing of the state of the principal part at the time of carrying out the double winding fastening with the can body using the can lid.

As shown in FIGS. 1 and 2, the curl portion 1a, which is the peripheral portion of the can lid 1, is thinner toward the edge thereof.

To manufacture such a can lid 1, an upper mold 11 and a lower mold 12 as shown in FIG. 3 are used. As shown in FIG. 3, the lower mold 12 is formed such that the inner shape of its upper surface is the same as the desired lower surface shape of the can lid. On the other hand, the upper mold 11 has not only the inner shape of the lower surface thereof that is the same as the desired upper surface shape of the can lid, but as shown in FIG. 11a is formed. The protrusion 1 of the upper mold 11
1a is formed so that its thickness becomes thicker toward the outside in the radial direction, and the size of the maximum part of the thickness is equal to the target thickness of the can lid.

That is, the plate material 3 which is the material of the can lid is placed on the upper part of the lower mold 12, and the plate material 3 is placed on the upper mold 11 and the lower mold 1.
2 and the plate material 3 in the peripheral portion of the upper die 11 is pressed by the crease holder 13, the plate material 3 is compressed and the plate material 3 is punched out, so that the peripheral edge portion becomes thinner toward the edge side. The can lid 1 can be formed by bending the peripheral portion inward in the radial direction into a predetermined shape to form the curl portion 1a.
Is obtained.

When the can lid 1 thus obtained is wound in the same manner as the conventional one, the groove portion 23a of the first winding roll 23 comes close to the peripheral edge of the can lid 1 as shown in FIG. 5 (a)), even if the curl portion 1a of the can lid 1 enters the groove portion 23a of the roll 23 and the edge of the curl portion 1a and the groove portion 23a come into contact with each other (FIG. 5 (b)), Since the edge of the curl portion 1a is thin as described above,
The edge is curved along with the contact and faces the inside of the groove 23a, and the curved surface in the middle of the curl portion 1a contacts the groove 23a instead of the tip.

Therefore, even if a slip occurs in the contact portion, the curl portion 1a is bent without generating thin chips from the contact portion (FIG. 5 (c)), and the curl portion 1a is canned. It is wound inside the flange portion 2a of the body 2 (see FIG. 7).
(D)) can be performed.

Therefore, even if the first winding tightening similar to the conventional one is performed, thin chips are not generated, so that it is possible to prevent foreign matter from entering the can. Further, since the groove portion 23a comes into contact with the curved surface in the middle of the curl portion 1a, the groove portion 23a and the curl portion 1a are not scratched and smooth winding can be performed, and damage to the groove portion 23a is prevented. It is possible to prevent and extend the life of the roll 23.

[0015]

As described above, since the can lid according to the present invention has the peripheral edge portion whose wall thickness becomes thinner toward the edge, the edge is easily bent. For this reason,
When the winding roll and the edge end come into contact during the tightening with the can body, the edge end bends and the curved surface of the peripheral portion comes into contact with the roll instead of the edge end. Thin chips and the like are not generated from the contact portion between the peripheral edge portion and the roll, and foreign matter can be prevented from entering the can.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a can lid according to the present invention.

FIG. 2 is an enlarged enlarged view of an arrow II in FIG. 1;

FIG. 3 is a cross-sectional view showing the structure of a mold used for manufacturing the can lid.

FIG. 4 is an enlarged view of an arrow IV in FIG.

FIG. 5 is an explanatory diagram of a state of a main part when double canning is performed with a can body using the can lid.

FIG. 6 is an external view when double-tightening a can lid and a can body.

FIG. 7 is an explanatory diagram of a state of a conventional main part at that time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 can lid 1a curl part 2 can body 2a flange part 3 plate material 11 upper mold 11a protrusion 12 lower mold 13 wrinkle retainer 23 first winding roll 23a groove

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 25, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art A process of double-tightening a can lid around a can body to seal the inside of the can will be described with reference to FIGS. As shown in FIG. 6, a can body 32, in which beverages and the like are placed and a can lid 31 is placed on the upper portion, is placed on a rotating lifter base 21, and the lifter base 21 is raised to rotate a chuck. 22 can lid
31 engaged, and further raising the lifter stand 21, Ru applying a compressive load between the can lid 31 and can body 32.

[Procedure amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction contents]

Next, the roll 23 is moved so that the groove portion 23a of the first winding roll 23 rotatably supported approaches the peripheral edge of the can lid 31 (FIG. 7A), and the roll 2 concerned.
Curl portion 3 which is the peripheral portion of can lid 31 in groove portion 23a of
1a is inserted (FIG. 7 (b)) and the roll 23 is attached to the can lid 3
1 and the curl portion 3 by moving to the center of rotation of the can body 32.
By bending 1a (FIG. 7C) and further moving the roll 23 to wind the curl portion 31a of the can lid 31 inside the flange portion 32a of the can barrel 32 (FIG. 7D),
Tighten the first winding.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

When the can lid 31 and the can body 32 are wound and fastened as described above, the first winding roll 23 is rotated at a rotational speed of the can lid 31 due to frictional resistance of the shaft supporting portion. Since the peripheral speed is slightly slower, the curl portion 31a of the can lid 31 and the groove portion 23 of the first winding roll 23
Slip will be generated between a and a. If such a slip occurs, when the edge of the curl portion 31a of the can lid 31 and the groove portion 23a of the first winding roll 23 come into contact with each other, as shown in FIG. There is a possibility that a cutting action will occur in the contact portion and thin chips will be generated from the contact portion.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

If the thin chips as described above are generated, there is a possibility that the thin chips may get into the can, which is a problem .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

When the can lid 1 thus obtained is wound in the same manner as the conventional one, the groove portion 23a of the first winding roll 23 comes close to the peripheral edge of the can lid 1 as shown in FIG. 5 (a)), even if the curl portion 1a of the can lid 1 enters the groove portion 23a of the roll 23 and the edge of the curl portion 1a and the groove portion 23a come into contact with each other (FIG. 5 (b)), Since the edge of the curl portion 1a is thin as described above,
Face inward of the groove 23a the edge is curved with the above contact, a curved surface of the middle of the curled portion 1a comes into contact with the groove 23a in place of the edge.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Therefore, even if the first winding tightening similar to the conventional one is performed, thin chips are not generated, so that it is possible to prevent foreign matter from entering the can. Further, since the groove portion 23a comes into contact with the curved surface in the middle of the curl portion 1a, the groove portion 23a and the curl portion 1a are not scratched and smooth winding can be performed, and damage to the groove portion 23a is prevented. It is possible to prevent and extend the life of the roll 23. In addition, the second winding roll 24 is used to
The second winding tightening is performed, and the edge of the curl portion 1a of the can lid 1 is closed.
Even if the end comes into contact with the can body 2, the edge is still the first winding described above.
Since it bends in the same way as when tightening, the shake of the can body 2
It is possible to prevent damage such as.

Claims (1)

[Claims] 1. A can lid characterized in that it has a peripheral portion whose wall thickness decreases toward the edge.