Cylindrical casing closure for electrolytic capacitors - has annular support surface of dia. larger than outer dia. of terminal rivet plate, and with pressure relief arrangement

摘要

The cylindrical metal casing of the electrolytic capacitor has a cover disc hermetically inserted as a closure element, having an inserted terminal for connection to an external lead, the terminal being connected to the capacitor on the disc inside. The disc is of durable, elastic material with a plate rivet as the terminal. The outside of the disc abuts an annular support surface whose width corresponds to the spacing of the rivet plate from the casing. The inner diameter of the annular support surface (14) is somewhat larger than the outer diameter of the rivet plate (8). The thickness of the disc (4) is so rated that the rivet plate exerts a shearing force on the disc, when an overpressure is generated in the casing (1), exceeding a preset limit. The shearing force is rated to break the disc, which permits the rivet plate to be pushed out of the disc mounting.