| 摘要 |
<p>The screw-on top for closing bottles is made from plastic. It consists of the screw sleeve (1) inside which the internal thread (2) is located. A collar (7) is attached to the leading end of the screw sleeve (18) by a location flange (12). A shear -off ring (8) is linked to the collar (7) by thin radial webs (9). When the bottle is opened for the first time, the twisting action on the screw top (1) breaks the thin webs (9). Thus the screw top can be removed whilst the shear ring (8) is retained by an external flange on the bottle screw. A loose shear ring therefore proves that the bottle has been opened.</p> |
