Numerically controlled shearing machines

84.62 - Machine-tools (including presses) for working metal by forging, hammering or die-stamping; machine-tools (including presses) for working metal by bending, folding, stra htening, flattening, sheanng, punchin or notching; presses for working met or metal carbides, not specified above 8462.10 (+f - Forging or die-stamping machines (including presses) and hammers - Bending, folding, straightening or flattening machines (including presses) : 8462.2 1 - - Numerically controlled 8462.29 - - Other - Shearing machines (including presses), other than combined punching and shearing machines : 8462.31 - - Numerically controlled 8462.39 - - Other - Punching or notching machines (including presses), including combined punching and shearing machines : 8462.4 1 - - Numerically controlled 8462.49 - - Other - Other 8462.91 - - Hydraulic presses 8462.99 - - Other The heading covers certain machine-tools, listed in the heading text, which work by changing the shape or form of metal or metal carbides. In general machine-tools are power-driven but similar machines, worked by hand or edal, are also covered by this heading. These latter types can be distinguished from the han tools of heading 82.05 and ftom the tools for working in the hand of heading 84.67, by the fact that they are usually designed to be mounted on the floor, on a bench, on a wall or on another machine, and are thus usually provided with a base plate, mounting fiame, stand, etc. ! The heading includes : (1) For 'ng and stampin machines, Broadly speaking forging includes all processes for wor ng heated meta by im act or by ressure, either to eliminate puddling sla (shinglmg) or to shape the metaf Except in J e case of shingling where the metal is worke in the form of balls, the metal to be shaped is either in the form of semi-finished roducts such as blooms, billets or sheet bars, or in the form of bars and rods, usually o circular section. Forging can be described more precisely as an operation which uses heat but no dies. ? b2 % P k Stamping or cutting out) is a process for forcing metal, by impact or pressure to fill the hollows o metal moulds called dies. This operation is carried out hot for hard metals (notably steel) or cold for soft metals. Generally a press is used. In the process of stamping or cuttin out, the dies completely enclose the workpiece. In certain cases, however, a slngle rneta die operating on only one part of the unworked piece is used. This die is then called a stamp and the operation is termed stamping. f Stamping machines can eliminate the " flash " produced during stamping or cutting out. This trimming o eration is carried out with the aid of special cutting dies. The finishing operation came out by a precision die-stamper is, in fact, described as sizing. This sizing produces the necessary precise dimensions. The following are exam les of machine-tools specially designed and built for carrying out the operations describe above : - Hammers, drop forges and drop hammers (mechanical, hydraulic or pneumatic hammers and steam hammers) whch operate by a series of short, sharp shocks. - Metal working presses, which operate by continuous ressure. However, general resses not specially designed for metar working are excluded l4.79). r (2) Bending machines. These include machines for working flat products sheets, plates and strips) which, by assing the products throu h three or four sets of ro lers, give them a cyl~ndricalcurve (?or this the rollers are par lel as with tube formin machines) or else a conical shape (in which the rollers are not parallel); machines f&r working non-flat ars, rods, angles, shapes, sections, tubes). These machines work either by means of ormin rollers, by press bending, or, for tubes and, in particular, oil pipes), by drawing their en s while the main section is held by a fixe cylinder. f % (3) Folding machines. These machines include the following : (a) machines for working flat roducts. The folding of a flat product consists of giving a sheet (or strip) in a straig t line a permanent deformation of small radius, without rupturing the metal. This operation is carried out, either on a universal folding machine, or on a folding press; R (b) machines for working non-flat products. The folding of bars, rods, tubes, angles, shapes and >ections is akin to forming (see paragraph (2) above); wire bending involves givlng ~t a curvature within a slngle plane. Wire bending machines carrying out more complex o erations (for exam ley spring manufacturing machines) do not constitute simple fol i g machines and fa 1in head~ng84.63. I' (4) Straightening machines and flattenin machines. These machines are for remedyin imperfections in non-flat products, suc% as wire, bars, rods, tubes, angles, shapes an sections, or flat products, such as sheets or strip, arising during their manipulation after manufacture. Flattening machines include the following, for example : s. (a) Flattenin machines of the roller type which consist of a series of arallel rollers (or cylindersk, either small in number (5 to 11) but of relatively large lameter and great rigidity, or lar e in number (general1 15 to 23) but of small diameter, great flexibility, and supported y an equal number o counter rollers; % P (b) Tables for flattening by drawing in which imperfections are eliminated by slight permanent stretching. (5) Shearing machines. The shearing process involves two cutting tools with faces in the same plane applied vertically to the metal to be cut. These tools penetrate the metal which is subjected to plastic deformation and the fibres of which, under progressively more and more pressure and penetration, rupture along the line of the blades. Machines of this type include : balance shears, lever shears and guillotine shears which use blades; rotary shearing machines which, instead of blades, use tools in the form of discs or frustums of cones. (6) Punching machines used for perforating, notchin or cutting metal by means of two tools ad'usted one inside the other. The unching too is called the punch while the other is ca led the die. Rupture of the meta is effected as in shearing and the shape of the hole obtained depends on the shape of the tools. P f The different machines of this type include machines for making gears by punching. (7) Notching machines are small machines used for workin various sections (L, T, I or U sections) and half-rounds, either to prepare them for assem ly (for example, grooves, slots, tenons and dovetails), or simply to cut or pierce them. % (8) Extruding presses for extruding bars, rods, wire, angles, shapes, sections, tubes, etc. These presses are designed to force a mass of metal through an extrusion die with the help of a punch. Depending on the malleability of the metal, t h ~ soperation is carried out hot or cold. (9) Presses for moulding metallic powders by sintering. (10) Presses for compressing metal scrap into bales. PARTS AND ACCESSORIES Sub'ect to the general provisions regarding the classification of arts (see the General Exp anatory Note to Section XVI),parts and accessories (other than t e tools of Chapter 82) of the machine-tools of this heading are classified in heading 84.66. f The heading also excludes : (a) Hand tools (heading 82.05). (b) Machining centres, unit construction machines (single station) and multi-station transfer machines, for working metal (heading 84.57). (c) Tools for working in the hand, pneumatic, hydraulic or with self-contained electric or non-electric motor (heading 84.67). (d) Machines for stamping address plates (heading 84.72). (e) Pig iron breakers and special stamping mills for breaking up cast iron scrap (heading 84.79). (f) Machine-tools for bending, folding and straightening semiconductor leads (heading 84.86). (g) Testing machines and apparatus (heading 90.24).