摘要 |
PCT No. PCT/GB96/03028 Sec. 371 Date Dec. 24, 1998 Sec. 102(e) Date Dec. 24, 1998 PCT Filed Dec. 9, 1996 PCT Pub. No. WO97/21602 PCT Pub. Date Jun. 19, 1997The invention provides container closure assemblies, especially for carbonated beverage containers, having substantially helical second thread segment (20) with a profiled lower thread surface (24). The profiled lower thread surface (24) includes a first, lower region (28) with a low pitch and a second region (30) with a steep pitch. The thread (20) may also include a step feature (32) to block unscrewing of the closure at an intermediate position where gas venting can take place, and a third region (34) of the said lower surface having a low pitch adjacent to the step. The closures are easy to apply and remove, and do not blow off unpredictably or uncontrollably under pressure.
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