Matsushita Electric Industrial Co., Ltd.

Fumiaki Seta

Yasuyuki Yoshihara

Kazuyoshi Yonezu

Go Kashio

Akira Iwamura

Akira Inanobe

Kunio Makino

Akitoshi Hiramatsu

Rikio Miyagi

An electrode includes an expanded grid and an active material provided on the grid, the thickness of the grid is the same as the strand and connecting sections of the strand, presenting a waveform as a whole. When this grid is used in the electrode as a current collector, the connecting sections are located near the center of the thickness direction of the electrode and strand are arranged by projecting upward and downward, respectively, from the boundary where the connecting sections are situated. Accordingly, a lead-acid storage battery having long life characteristics is made available.

Storage battery

A lead-acid storage battery uses as a current collector an expanded grid produced by processing a belt shaped material formed of lead or lead alloys. Strand of a grid for negative electrodes have a twist. The extent of the negative electrode's grid is larger than that of the positive electrode's grid. Accordingly, degradation of output characteristics in the domain deep in the depth of discharge is prevented and further high rate discharge cycle life characteristics are improved.

The apparatus comprises a reticulating machine (,) for simultaneously producing in metal sheet (,) of strip form a plurality of slits (,) disposed in a continuous and zigzag arrangement extending in the lengthwise direction thereof, and an expanding machine (,) for expanding in the lateral direction the metal sheet (,) in which slits (,) have been formed in order to produce a lozenge-shaped mesh configuration. The expanding machine (,) comprises two endless conveyor elements (,) disposed at the two lateral edges of the metal sheet (,), chuck members (,), a plurality of which are provided in an equally-spaced arrangement to the endless conveyor elements (,), and a center guide member (,) for conveying the metal sheet (,) while guiding the transverse central portion such that it is deflected to one side in the direction of thickness of the metal sheet (,). The chuck members (,) grip the lateral edges of the metal sheet (,) in which slits (,) have been formed, thereby expanding the metal sheet (,) while conveyed by the endless conveyor elements (,).

Apparatus for expanding a metal sheet

A number of strap-forming metal molds 12 corresponding to the number of steps are arranged on a circumferential track and are fed to the devices of the respective steps A.about.F together with electrode plate groups 10. Position A is an electrode plate group 10 introduction position; position B is a flux coating position in which electrode plate leads 6 are coated with flux; position C is an auxiliary heating position in which a mold 8 is heated to the temperature of the molten lead; position D is a molten lead pouring position in which molten lead is poured into a mold 8; position E is a strap-forming position in which electrode plate leads 6 are inserted into the molten lead, fused and cooled and the molten lead is solidified; position F is a discharge position in which a completed electrode plate assembly is discharged. Heating of a mold 8 is commenced by inductive heating from position F and is continued to position E.

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Aichi, Japan

Fumiaki Seta