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本帖最后由 foolhorse 于 2011-7-28 09:14 编辑
回复 19# ftsh18
The Alimentary Tract of a Fountain Pen comprises three organs: the ink reservoir, the nib, and the feed by which these two are connected so that ink may pass from the one to the other. The release of ink by a fountain pen has been referred to as a “controlled leak,” and it is the feed that exercises that control. To do so requires a surprising degree of sophistication; not only must the feed meter the amount of ink flowing to the nib, but it must also permit just the required amount of air to flow in the opposite direction, to replace the ink as it is used.
Cutaway view of nib, feed, section, and sac
Because the problems of airflow control were not suspected, early feeds were designed only to provide a capillary surface across which ink (but not too much of it) could pass on its way to the nib slit. A very simple approach to this problem is to make a feed that is slightly smaller in diameter than the bore of the section and wedge the feed into the bore with a piece of wire so that the feed is in contact with the surface of the nib and the bore itself. Some early pens, such as Mabie Todd Swan overfeed models, used this approach. But a simple feed of this type has no way to meter air into the reservoir; as ink is used, a partial vacuum builds up in the reservoir, holding the ink in instead of allowing it to flow out. When external air pressure is sufficient to overcome the ink’s surface tension, a bubble is forced into the reservoir. (This frequently occurs when the writer disturbs the surface tension by shaking the pen.) The sudden release of the partial vacuum releases a drop of ink, which appears on the paper as a blot.
从Richard binder的网站里摘的,你自己先看看这段话吧。有兴趣的话去那里看看完整的关于笔舌设计进化的文章。你所谓的排气管(照字面翻译应该叫呼吸管)那篇文章里也说得很清楚,我就不贴上来了,自己去看吧。 |
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