| 摘要 |
550,334. Accumulator batteries. VARLEY DRY ACCUMULATORS, Ltd., FULLER, L., and LARK, H. D. July 4, 1941, No. 8442. [Class 53] A method of making a lead-acid accumulator of the " dry type consists of assembling the electrodes whilst still unformed and the separating material within the container and subsequently forming the electrodes by passing a current. Preferably the electrodes are pasted with the usual lead oxide and acid mixture. Owing to the active material being held on to the plates by the filling of separating material used in " dry " accumulator batteries, the acid employed for the forming charge may be of normal strength without causing disintegration of the plates, so avoiding the necessity of replacing it after the forming charge. Preferably the mixtures used for pasting the negative and positive plates are such that they become completely formed simultaneously, a suitable mixture for the negative plates being 75 parts by weight of litharge and 25 parts of red lead and for the positive plates 50 parts each of litharge and red lead, moistened in each case with sulphuric acid of 1.100 specific gravity. Before filling the cell with acid, air trapped in the pores of the electrodes and filling material is drawn off by a vacuum. Single cells may be immersed in acid during the forming charge. The cell shown comprises a cylindrical lead container 10 in an outer insulating casing 19, a layer 11 of negative active material, separating material 13, a layer 15 of positive active material, and a central conductor 14. A porous ceramic disc 17 held by a lead ring 18 burnt to the container maintains the contents under pressure. Specifications 257,019, [Class 53], 432,775, and 506,062 are referred to. |
