LIQUID/LIQUID, LIQUID/GAS OR GAS/GAS SEPARATION Method General operations by centrifugal force, using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force, using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/LIQUID OR SOLID/GAS SEPARATION Method General operations by centrifugal force using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/SOLID SEPARATION Method Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods Apparatus Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus , Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods This class covers: operations not provided for in any other class; combinations of operations covered by different subclasses of classes , which combinations are covered by subclass , with the exception of subsidiary operations performed in conjunction with main operations covered by a single subclass; features, specific to machine tools, which relate to a requirement or problem of a nature which is not peculiar to a particular kind of machine tool, e.g. feeding work, which are covered by subclass , although the realisation of these features may differ according to the kind of machine tool concerned. The said subclass covers such features, in general, even if the feature or a specific function, in any particular case, is to some extent peculiar to, or is claimed only for, machine tools designed for one particular operation; only in exceptional cases are such features classified in the subclass for the machine tool concerned. Certain features of this general nature are, however, referred to subclasses relating to particular metal-working operations, especially , in which case the subclasses in question are not restricted, in respect of those features, to the kind of machine tool with which they are primarily concerned. In this class, the following terms or expressions are used with the meanings indicated: "metal-working" covers the working of other materials unless the context requires otherwise; "kind of operations" and similar expressions relate to such metal-working operations as boring, drilling, milling and grinding; "kind of machine" means a machine designed for a particular kind of metal-working operation (e.g. a lathe); "form of machine" means a machine of a particular kind adapted or arranged for a particular way of working or for particular work, e.g. face-plate lathe, tailstock lathe, turret lathe; "different machines" covers different forms of machines for performing the same type of metal-working operation, e.g. vertical and horizontal boring machines. If details, components, or accessories have no essential feature specific to machine tools, the more general class, e.g. , takes precedence. TURNING Methods Lathes general-purpose lathes semi-automatic or automatic lathes , , for particular work handling, adjusting , component parts headstocks, tailstocks, chucks , , tools, or holders therefor , other parts , , accessories BORING, DRILLING Methods , Machines general-purpose machines for particular work hand-held machines component parts , , DEVICES FOR ATTACHMENT TO ANY MACHINE TOOL MILLING MACHINES IN GENERAL MILLING PARTICULAR WORK COMPONENT PARTS, ACCESSORIES , DEVICES FOR ATTACHMENT TO ANY MACHINE This subclass covers machines for shearing sheet metal or other stock material except metal foils workable in a manner analogous to paper, which is covered by class . PLANING; SLOTTING Working method of the machine , , Machines characterised by constructional features of a part Hand-operated devices; portable apparatus Devices for attachment to any machine tool Tools, tool holders SHEARING Working method of machines or apparatus , , , , Hand-held devices , , Tools, holders, chucks Accessories Machines for particular work , , Control arrangements BROACHING; REAMING Working method of machines or apparatus Machines or devices characterised by constructional features of a part Tools , Accessories Machines or devices for reaming bored holes SAWING Working method of machines or apparatus using saw discs , using straight saw blades , using endless saw blades , other working methods Machines or devices characterised by constructional features of a part , , Tools and attachment thereof; dressing thereof; making thereof , ; ; Accessories Control arrangements FILING; RASPING Working method of machines or apparatus Machines or devices characterised by constructional features of a part Tools; making thereof ; OTHER METHODS, MACHINES, OR DEVICES; COMBINATIONS ; This subclass covers: the use of methods or apparatus specially designed to produce accurately the shapes of gear teeth which are essential for proper intermeshing of toothed gearing elements to ensure the required relative motions; the use of similar methods or apparatus in the production of other articles of toothed or like form, e.g. dog clutches, splined shafts, milling cutters. This subclass does not cover the production of such other articles of toothed or like form using methods or apparatus other than those mentioned under Note (1) above. In this subclass, the following terms or expressions are used with the meanings indicated: "gear teeth" covers the teeth or lobes of other accurately-intermeshing members having relative movement of a similar kind, such as rotors of rotary pumps and blowers; "profile" may include the outline of both faces or only one face of a tooth, or the opposing faces of adjacent teeth; "straight" means that a tooth as a whole (ignoring any curvature of the tooth-face alone, e.g. crowning) is straight in the direction of its length, for example as seen in the direction of a radius of a spur wheel. It accordingly includes the teeth of helical gears and of the normal type of bevel gear; "broach-milling" means milling with a rotary cutter having a number of teeth of progressively increasing depth or width. MAKING GEAR TEETH General methods , , Making teeth with special shape , , , , Finishing Tools; accessories ; MAKING WORMS Methods Worm wheels Accessories MAKING OTHER GEARING WHEELS OF SPECIAL TYPE In this subclass, the following expression is used with the meaning indicated: "thread cutting" includes the use of tools similar both in form and in manner of use to thread-cutting tools, but without removing any material. THREAD-CUTTING METHODS, MACHINES OR DEVICES THEREFOR , , , FINISHING TOOLS , ACCESSORIES This subclass covers the working of metal described as "electroerosion". ELECTRICAL DISCHARGE MACHINING ELECTROCHEMICAL MACHINING COMBINED MACHINING COMMON PROCESSES OR APPARATUS MACHINING PARTICULAR OBJECTS OR OBTAINING SPECIAL EFFECTS OR RESULTS AUXILIARY APPARATUS OR DETAILS This subclass covers also electric circuits specially adapted for the purposes covered by the title of the subclass. In this subclass, the following term is used with the meaning indicated: "soldering" means uniting metals using solder and applying heat without melting either of the parts to be united. In groups , it is desirable to add the indexing codes of groups or . SOLDERING , WELDING Characterised by the means used to produce heat by flame by electricity , , by means of plasma by nuclear particles , by alumino-thermic means by laser beam otherwise , Characterised by the use of impact or pressure Characterised by other features, processes not restricted to one particular group of this subclass CUTTING BY APPLYING HEAT LOCALLY; SEVERING , , , , ; SCARFING, DESURFACING MATERIALS; AUXILIARY DEVICES ; SPECIAL PROCESSES , This subclass does not cover non-mechanical operations on non-metallic materials unless such operations are specially mentioned in this subclass. In this subclass, the following expressions are used with the meanings indicated: "combined operations" excludes the assembling of parts if it is an essential feature of the next metal-working operation, since it is not regarded as an operation per se; "working of metal" and equivalent expressions include non-mechanical treatment of metal so far as it is not provided for in any other class or subclass, for example, in , , , . Thus, combinations of such non-mechanical treatment with other metal-working are classified in this subclass. Attention is drawn to the Notes following the title of class . METAL-WORKING PROCESSES Setting of diamonds Reconditioning; finishing ; Connecting or disconnecting , , Other processes , , , Auxiliary treatments COMBINED PROCESSES; MULTI-PURPOSE MACHINES Reconditioning; finishing ; Other combined operations , Auxiliary treatments In this subclass, groups designating parts of machine tools cover machine tools characterised by constructional features of such parts. In this subclass, the following terms or expressions are used with the meanings indicated: "controlling" means influencing a variable in any way, e.g. changing its direction or its value (including changing it to or from zero), maintaining it constant, limiting its range of variation; "regulation" means maintaining a variable automatically at a desired value or within a desired range of values. The desired value or range may be fixed, or manually varied, or may vary with time according to a predetermined "programme" or according to variation of another variable. Regulation is a form of control; "automatic control" is often used in the art as a synonym for regulation. Attention is drawn to the Notes following the title of class . BASIC COMPONENTS OF MACHINE TOOLS , DEVICES FOR SUPPORTING, HANDLING, OR FEEDING WORK OR TOOLS , , AUXILIARY EQUIPMENT, SAFETY DEVICES , , MEASURING; INDICATING; CONTROLLING Controlling the movements of the tool or work , , Indicating COPYING , MACHINES COMPRISING UNITS OR SUB-ASSEMBLIES, TRANSFER MACHINES, ASSOCIATIONS OF MACHINES OR UNITS , ,