| 摘要 |
<p>The cap comprises three pieces which have to be placed on the neck of the container in turn. Firstly a cylindrical piece (3) having a collar (3") and a central opening (3") is slipped over the container's neck. Then a ring piece (4), fitting between the cylindrical piece and the container, and having an internal screw thread is screwed onto the neck with a spurred key which fits into notches (7, 7) in the ring. Lastly a cowl (5) with an internal airtight joint(6) is screwed onto the cylindrical pieces that it and the cylindrical piece can now rotate freely around the container's neck. To remove the cowl, the collar must be held firmly while the cowl is turned.</p> |
