| 摘要 |
471,214. Batteries. NATIONAL CARBON CO., Inc. April 1, 1936, No. 9614. Convention date, March 18. [Class 53] A dry cell having a metal cover and a container forming one electrode is provided with a protective layer which covers the joint between the cover and one or both of the electrodes. The protective layer consists of a thermoplastic or polymerizable material and may be applied to the joint after the cover has been secured in position. Fig. 1 shows the upper part of a cell having a metal cover A secured to the container Z and resting on an insulating washer W carried by the metal cap B on the carbon electrode C. The latter is treated to render it non-porous to liquids but permeable to gases which can escape through a perforation B<11> in the cap B. The cell cover is provided with a protective layer of material P which may be applied by placing a disc of the material on a partition K and then securing the cover in position, inverting the cell to cause the disc of material to drop on to the cover and then heating the cover to melt the disc. A smaller disc of material may be used so that when melted it covers only the joint between the cover and the carbon electrode as shown in Fig. 4, or it may be made to cover only the joint between the cover and the container Z. The material P may consist of various mixtures comprising asphalt, montan wax, talc, paraffin, tung oil, bituminous substances, chlorinated paraffin, rosin, rubber, stearic acid, tallow, &c., and it may be heated electrically, and instead of being introduced into the cell in the form of a disc it may be in the form of pellets placed on the partition K. Alternatively, the material may be poured in molten condition on to the partition K and the cover then placed in position and the cell inverted before the material has solidified. In a further method, the material is at first liquid but polymerizes into the solid form. For this purpose a mixture of tung oil, ferric chloride and acetone may be used. One of the constituents may be applied to the cover, the others being placed on the partition K so that the reaction is delayed till the cell has been inverted. Specification 356,271 is referred to. |
