【正文】 ing edge. Cutters of this type are sharpened by grinding only the face of the teeth, with the contour of the cutting edge thus remaining unchanged. Another useful method of classification is according to the method of mounting the cutter. Arbor cutters are those that have a center hole so they can be mounted on an arbor. Shank cutters have either tapered or straight integral shank. Those with tapered shanks can be mounted directly in the milling machine spindle, whereas straightshank cutters are held in a chuck. Facing cutters usually are bolted to the end of a stub arbor. The mon types of milling cutters, classified by this system are as follows: Types of Milling Cutters. Hain milling cutters are cylindrical or diskshaped, having straight or helical teeth on the periphery. They are used for milling flat surfaces. This type of operation is called plai n or slab milling. Each tooth in a helical cutter engages the work gradually, and usually more than one tooth cuts at a given time. This reduces shock and chattering tendencies and promotes a smoother surface. Consequently, this type of cutter usually is preferred over one with straight teeth. Side milling cutters are similar to plain milling cutters except that the teeth extend radially part way across one or both ends of the cylinder toward the :center. The teeth may be either straight or helical. Frequently these cutters are relatively narrow, being disklike in shape. Two or more side milling cutters often are spaced on an arbor to make simultaneous, parallel cuts, in an operation called straddle milling. Interlocking slotting cutters consist of two cutters similar to side mills, but made to operate as a unit for milling slots. The two cutters are adjusted to the desired width by inserting shims between them. Staggeredtooth milling cutters are narrow cylindrical cutters having staggered teeth, and with alternate teeth having opposite helix angles. They are ground to cut only on the periphery, but each tooth also has chip clearance ground on the protruding side. These cutters have a free cutting action that makes them partilarly effective in milling deep slots. 。crew and thus enable threads to be Construction. The essential ponents of a lathe are depicted in the block diagram. These are the bed, headstock assembly, tailstock assembly, carriage assembly, quickchange gear box, and the leaamp。 附件 2：外文原文 （復(fù)印件） LATHE AND MILLING The basic machines that are designed primarily to do turning, facing and boring are called lathes. Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathe can do boring, facing, drilling, and reaming in addition to turning, their versatility permits several operations to be performed with a single setup of the workpiece. These accounts for the fact that lathes of various types are more widely used in manufacturing than any other machine tool. Lathes in various forms have existed for more than long long age. Modem lathes date from about 1797, when Henry Maudsley developed one with a leaamp。這種銑刀的側(cè)面呈盤狀，有間隙，可以防止粘連。這種類型的銑刀可用于高速切削，在銑削深槽時(shí)可以發(fā)揮獨(dú)特的作用。 錯(cuò)齒銑刀是較薄的圓柱形銑刀，刀上有相互交錯(cuò)的刀齒，相鄰刀齒具有相反的螺旋角。 雙聯(lián)槽銑刀是由兩個(gè)側(cè)刃銑刀組成，但是在銑槽時(shí)，作為一組銑刀進(jìn)行操作。側(cè)刃銑刀的刀齒既可以是 直線的，也可以是螺旋形的，這種銑刀一般較窄小，具有盤形的形狀。因此，與直齒銑刀相比，這種類型的銑刀，通常使用得更多。它們可以用來銑削平面，這種銑削稱做平面銑削。 帶柄銑刀：端面銑刀， T 形槽銑刀，整體式銑刀，半圓鍵座銑刀，套式銑刀，高速切削刀，空心銑刀。 平面銑刀通常用螺栓固定在刀軸的末端上。心軸銑刀帶有一個(gè)中心孔以使銑刀安裝在心軸上。偏心后角的各面與切削刃平行，具有切削刃的相同形狀。 銑刀 銑刀分類有多種方法，一種方法是根據(jù)刀具后角將銑刀分為兩大類： 1．仿形銑刀每個(gè)刀齒在切削刃的背面磨了一個(gè)很小的棱面形成后角，切削刃可以是 直線或曲線的。順銑的弱點(diǎn)是銑刀齒