| 摘要 |
<p>The container has a cylindrical body with flanges located at the top or bottom. The base of the container is concave to add strength, and is seamed to the body by rolling the flanges and the edges of the base together. The top cover (b) is fixed to the cylinder in exactly the same way at the edges (5). The centre of the lid (6) is pierced with a circular hole. The hole is sized to take a plug (8) which is sealed to the tin by rolling the edges over (9) in the same way as at the rim of the tin. The valve (7) is inserted into the plug and operates from this point.</p> |
