PURPOSE: To prevent incomplete opening from occurring by making a neck of a rivet wherein a front end is a first arc having a radius of curvature relatively small and a rear half is a second arc having a radius of curvature larger than that of the first arc while a center of curvature of the second arc aligns with a center of a panel.
CONSTITUTION: An approximately rear half 15a2 of a neck 15a of a rivet 15 comprises a second arc having a radius of curvature larger than that of a first arc 20. Therefore, a recess is less likely to occur on the rear half 15a2 of the neck 15a. A front end 15a1 of the neck 15a of the rivet 15 comprises a first arc 20 having a relatively small radius curvature. Therefore, since a close arc part 14b along the neck front end 15a1 of a score line 14 has a small radius of curvature, it can be easily cut initially. Since a center of curvature O of the second arc occupying a most part of the neck 15a of the rivet 15 aligns with a center of a panel 11, positioning at the time of fixing the rivet 15 and a picking tab 17 is easy.
| JP2002337867 | TAB FOR OPENING CAN AND LID FOR CAN |
| JPH07277325 | BOX WITH SEALING TAB |
KUROSAWA KAZUYUKI
TANAKA MASASHI
IWAMOTO HISAO
