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 In this class, the following term is used with the meaning indicated: "vehicle" means all vehicles except those restricted to one of the following types of vehicles: rail vehicles, waterborne vessels, aircraft, space vehicles, hand carts, cycles, animal-drawn vehicles, and sledges, which are covered by the relevant subclasses of . Thus the term "vehicle" includes: vehicular characteristics which are common to more than one of the above-listed types; certain characteristics restricted to automobiles, road or cross-country trailers. The following exceptions to the above should be noted: subclass or embrace all vehicle wheels and tyres, except wheels for roller skates , wheels for model railway vehicles , and special adaptations of wheels or tyres for aircraft ; subclass embraces the connection of valves to inflatable elastic bodies in general, and in this respect it is not limited to vehicles; subclass embraces certain electric equipment of all electrically-propelled vehicles; subclass embraces certain power supply equipment for, but external to, any kind of electrically-propelled vehicle; subclass embraces safety belts or body harnesses used in all types of land vehicles; subclass relates to all kinds of vehicles, except the servicing of rail locomotives , ground equipment for aircraft , or cleaning apparatus peculiar to waterborne vessels , ; subclass includes brake control systems of general applicability, and in this respect it is not limited to vehicles. It also includes rail-vehicle power-brake systems and some other features of rail-vehicle brake systems. This subclass covers: overhead, overground, or underground power-supply lines; their crossings and points, erection and supervision; devices along rails and rail joints, for current-conduction and for insulation; safety devices along the route against earth currents and inductive interference with nearby communication lines.