Distributors; ignition coils

85.11 - Electrical ignition or starting e compression-ignition internal magneto-dynamos, ignition generators (for example, conjunction with such engines. kind used for spark-ignition or (for example, ignition magnetos, and glow plugs, starter motors); and cut-outs of a kind used in - Sparking plugs 8511.20 - Ignition magnetos; magneto-dynamos;magnetic flywheels 8511.30 - Distributors; ignition coils 85 11.40 - Starter motors and dual purpose starter-generators 8511.50 - Other generators 8511.80 - Other equipment 8511.90 - Parts 8511.10 This heading covers electrical starting or ignition equipment and appliances for internal combustion en ines of any kind (piston or other types), whether for use in motor cars, aircraft, boats or the lge, or for stationary engines. It also covers generators and cut-outs for use in conjunction with such internal combustton engines. The heading includes : (A) Sparking plugs. These consist of a central insulated electrode and a point (or oints) attached to the casing. The casing is artly threaded at its base for screwing it into t e cylinder-head, and there IS a terminal at e top of the central electrode for connection to the source of current. When a high voltage is applied to the central electrode a spark jumps between that electrode and the point or points and is used for igmting the explosive mixture in the cylinder. R t& (l3) Ignition magnetos (including magneto-dynamos). These are used to provide the necessary hi h tension voltage to be applied to the sparking plugs of an internal combustion engine; fhe are used mainly for racing cars, tractors, aircraft, motor-boat or motor-cycle engines. T ey are of the following main types : E (I) Revolving armature magnetos. These incorporate a form of AC generator in which an armature, wound with a primary low tension coil, rotates between the poles of a permanent magnet. This primary coil is connected to a contact breaker and capacitor, and the sudden making and breaking of the current in this coil induces very high voltage in a secondary winding. The whole is usually built in one housing, on the top of which a distributor arm is mounted to distribute the voltage to the sparking plugs in turn. (2) Stationary armature magnetos. These are of two types. In both the armature winding, contact breaker and capacitor are stationary; but in one type the magnets revolve, whereas in the other type, the magnets are also stationary and soft iron inductors revolve between the magneto and the mature winding. r' (3) Magneto-dynamos. These comprise a ma eto and a dynamo combined into a single unit with a common drive; they are normal y used on motor-cycles. (C) Magnetic flywheels. These consist of a magnetic device fitted to a flywheel to produce a low tension current for ignition purposes. (D) Distributors. These distribute the ignition current to the sparking plugs in turn, and also incorporate an intempter to make and break the circuit in the rimary winding of the ignition coil; both functions are synchronised with the strokes o f t e pistons in the cylinders by means of a cam driven by the engine. R (B) Ignition coils. These consist of specially modified induction coils, usual1 in a c lindrical container. By connecting the primary via an intern ter to the battery, a Kigh vogage is produced in the secondary and is led to the sparking p ugs via a distributor. f r In some ignition systems a double-spark ignition coil is connected direct1 to two sparkin lugs and the coil generates an i tion spark in each plug simultaneous y, with the spari? gorn one plug producing its cyEder power stroke and the spark fiom the other plug having no effect on its cylinder because it is on the exhaust stroke. Such systems do not require a distributor as the ignition coil is connected directly to the s arkin plugs. In these systems the coils are energised by an electronic (semiconductor) coi modu e. f ? (F) Starter motors. These are small electric motors, usually of the DC series wound type. They are fitted with a small pinion capable of travelling up and down a screwed shaft, or with some other mechanical device for coupling them temporarily to the internal combustion engine to be started. (G) Generators (dynamos and alternators). r These are driven b the engine, and serve to char e the batteries and to su pl current to the li hting, signaling, heating and o w electrica equipment of motor ve c es, aircraft, etc. A ternators are used with a rectifier. S R, (HJ Booster coils. These are small induction coils used, mainly on aircraft, when the turning speed at starting is too low for the engine magnetos to function. (IJ) Glow plugs. These are similar to sparking plugs, but in lace of the electrode and points for producing a spark, they have a small resistor which, w en current is passed, becomes heated. They are used to heat the air in the cylinders of diesel engines before and during starting. R (K) Heating coils. These are intended for mounting in the air intake of diesel engines for starting purposes. (L) Dynamo cut-out apparatus. These revent the dynamo from being driven as a motor, at the expense of the battery, when tle engine is stationary or turning at low speed. Cut-outs combined, in a single housing, with a voltage regulator or a current regulator are also classified here. In addition to protecting the battery and the dynamo, these devices ensure a constant flow of charge current or limit the intensity of this current. PARTS Sub'ect to the general provisions regarding the classification of parts see the General Exp anatory Note to Section XVI), parts of the goods of this heading are also c assified here. \ ! The heading excludes : (a) Engine starters as used on airfields, bus stations, etc., for startin internal combustion engines and consisting essentially of a transformer and rectifier (heading RS.OR. (b) Electric accumulators (heading 85.07). (c) Dynamos for use on bicycles for lighting purposes only (heading 85.12).