用普通万能銑床来銑切帶柄銑刀的螺旋槽,在操作上是比较麻煩的。这里介紹一种专用分度头,用它来加工螺旋槽,可以簡化操作。它的构造如附图所示,在分度头的座体1中鑲着一只襯套2,襯套里面穿进空心軸3。軸3的左端靠鍵連接着一只配换齿輪7,当銑切螺旋槽吋,它是傳递分度头的旋轉运动的。空 It is troublesome to operate the helical groove with a milling cutter with an ordinary universal milling machine. Here to introduce a special indexing head, use it to process spiral groove, can simplify the operation. Its structure is shown in the attached drawings, a bushing 2 is inserted into the base 1 of the index head, and a hollow shaft 3 is inserted into the bushing. The left end of the shaft 3 is connected with a key gear 7 by a key, which is the rotational movement of the indexing head when milling the spiral groove. air