As a result of pursuing flying distance, destructive power, shooting more than one arrow at the same time, the bow was mechanized by utilizing the principles of levers and pulleys or incorporating gear, pulley and spindle and the increase in size accordingly.
-飛距離・破壊力・複数の矢の同時発射などを追求した結果、梃子の原理や滑車の原理を利用し、歯車や滑車・錘などを弓に組込み、機械化またはそれに伴い大型化した。