1. 渐开线：依据历史的发展,先有学者确立了齿形的条件,之后才逐渐依序找出合乎此条件的齿形,即摆线(Cycloid)齿形与渐开线(Involute)齿形. Olaf Roemer在1674年曾发表齿形应采用外摆线(Epicycloid)曲线,不过,详细的记录被祝融毁之一炬,
2. involute
2. 渐伸线：渐伸线(involute)和渐屈线(evolute)是曲线的[def=%E5%BE%AE%E5%88%86%E5%B9%BE%E4%BD%95]微分几何[/def]上互为表里的概念. 若曲线A是曲线B的渐伸线,曲线B是曲线A的渐屈线.
3. 复杂,难解的：intervolve 互卷,卷合 | involute 复杂,难解的 | involve 牵涉,卷入,包括,意味著,需要
4. 渐开线,渐伸线：invisible spectrum 不可见辐射谱 | involute 渐开线,渐伸线 | involute curfe 渐开线齿轮
adj
1. (of some shells) closely coiled so that the axis is obscured
2. especially of petals or leaves in bud
having margins rolled inward
Synonym: rolled