| 摘要 |
<p>ADJUSTABLE FILTER CIGARETTE A variable dilution cigarette, of the type having a filter with two relatively rotatable segments having slits in the plug wrapping and the tipping paper which rotate in and out of rotational registry to vary the dilution level, is provided which is insensitive to slight longitudinal misalignment of the slits. An array of longitudinal depressions is formed in one segment of the filter plug centered on the slit in the plug wrapping and ending short of both ends of the filter segment containing the slit. The depressions act as a plenum allowing the longitudinal flow of air between the slit in the tipping paper and the slit in the plug wrapping in case of longitudinal misalignment arising during use, but do not allow circumferential air flow when the slits are intentionally deregistered by relative rotation of the filter segments. Because the depressions do not reach the ends of the filter segment containing the slit, they do not allow any unwanted air into the filter.</p> |
