Matsushita Electric Industrial Co., Ltd.

Masanori Makino

Ryuichiro Ebi

Tomomichi Ueda

Yoshio Goda

Tadahiro Tokumoto

A battery case () has a cutting groove () formed on its elongated side surface (). Between a groove bottom surface of the cutting groove () and an inner surface of the battery case () is provided a thin-walled easily-rupturable portion () designed to rupture at an instant when an internal pressure of the battery case () reaches a predetermined value. Thereby, a safety mechanism for use with a prismatic battery is realized. The manufacture of the safety mechanism is as follows. A cutting blade () rotated at a high speed by a high-speed rotary body () is brought into cutting engagement with the elongated side surface () of the battery case () of the prismatic battery in finished form until it reaches a predetermined depth and is fixed, and subsequently the high-speed rotary body () or the prismatic battery is brought into rectilinear relative movement.

Growing community of inventors

Daito, Japan

Masanori Makino