Contact for alkaline batteries with central rod electrode

Casing for an electric accumulator has a rectangular box form with shaped corners to the edges and base of the profile which stand proud of the main plane of each wall and the base. The raised borders are linked to the flat walls by a concave profile of radius at least as great as the height of the border. The ratio of the height of each border of its width lies in the range 0.05-0.3. The profile also features a rib across the underside of the base, the rib not being deeper than the border ribs around the base, and another rib or flange across the top of the casing through but not taller than integral terminal bosses. Used esp. for casings for alkaline accumulators, to provide adequate strength and stiffness for casings of constant wall thickness made by extrusion blow moulding compared with a casing of similar wall thickness without peripheral rib forms, the modified casings exhibited "much less" deformation in a top loading test, and withstand a 60 Hz vibration test at 1g acceleration 10 degree offset from the vertical axis without splitting along the edges.