| 摘要 |
<p>A cylindrical electric battery comprises a metal vessel formed by a bottom and a side wall, closed by a plastic cover integral with a plastic sheath enclosing the metal wall of the cell. The sheath has an annular zone close to the cover, thicker than the rest of the sheath and separated from it by an inner shoulder. This zone is in tight contact with the side wall of the vessel whilst the remainder fits with a certain amount of play, andis in cntact where the vessel has a smaller diameter than the body of the vessel. The thicker annular zone is produced during the moulding in one piece of the cover and the sheath, or it may be applied by overmoulding a tubular blank for the sheath with the plastic mass forming the cover. Alternatively the thicker zone may be formed by welding a piece forming the cover on to the blank for the sheath. An efficient seal between the bottom of the cell and its wall is long standing, but a better seal for the top, preventing leakage of the electrolyte between vessel and sheath and elsewhere outside, would make batteries cheaper to manufacture. A known seal is obtd. by shrinking on an "L"-section ring; the present proposals achieve the seal more easily and without using a separate piece.</p> |
