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IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ([N: anti-pollution means for internal-combustion engines F02B 17/00]; specially adapted for rotary-piston or oscillating-piston engines F02B 53/12; [N: ignition of gas turbine plants F02C 7/26; ignition of jet propulsion plants F02K 9/95; starting of combustion engines F02N 9/00]; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; [N: ignition coils H01F 38/12]; sparking plugs H01T 13/00)
Definition statement
This subclass/group covers:

Systems and arrangements for causing ignition in internal combustion engines.

Details of electrically actuated spark ignition systems, this includes the generation and supply of the ignition energy to the spark plugs.

Testing of and feedback about the ignition.

Control of the engine by using parameters of the ignition, e.g. the ignition timing or the ignition strength.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Ignition of gas turbine plants
Ignition of jet propulsion plants
Installations having electric ignition energy generated by magneto- or dynamo- electric generators without subsequent storage [N: (combination starter-magneto F02N 11/06; magneto- or dynamo-electric generators H02K 21/00 )]
Definition statement
This subclass/group covers:

Installations wherein spark ignition is generated by a spark plug fed by a coil responsive to the field changes of a magnet fixed on a flywheel and rotating with it. This is used in most of small engines without battery, as well as on small piston airplanes.

Layout of circuits
Definition statement
This subclass/group covers:

Circuits specially adapted to ignition circuits without batteries

Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of inductive ignition circuits
Details of capacitive ignition circuits
Control of ignition timing
[N: for generating sparks by opening or closing a coil circuit]
Definition statement
This subclass/group covers:

Circuits wherein the current which has been generated after a change of magnetic fields is transformed in (high) voltage by opening (here mechanically) the coil-plug circuit.

[N: for generating sparks by discharging a capacitor into a coil circuit]
Definition statement
This subclass/group covers:

Circuits with switching capacitors to increase the voltage created by opening the coil-plug circuit.

Other installations
Definition statement
This subclass/group covers:

Ignition installations comprising a battery, a switching circuit and an ignition transformer.

having inductive energy storage, e.g. arrangements of induction coils [N: (ignition coils structurally combined with sparking plugs F02P 13/00; constructional details of ignition coils H01F 38/12 )]
Definition statement
This subclass/group covers:

Circuits wherein a current is drawn into a coil storing magnetic energy and wherein the current is subsequently interrupted and the magnetic energy is discharged between the electrodes of a spark plug. In this group are mostly found:

  • the cabling of the coils;
  • the connection of the ignition coil to the spark plug connectors;
  • rod-type spark plugs.
Informative references
Attention is drawn to the following places, which may be of interest for search:
Ignition coils structurally combined with sparking plugs
Constructional details of ignition coils
having capacitive energy storage (piezo-electric or electrostatic ignition F02P 3/12 )
Definition statement
This subclass/group covers:

Circuits for capacitive discharge ignition (CDI) wherein a discharge current from a capacitor is used to generate the spark, usually by discharging the output to an ignition coil.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Piezo-electric or electrostatic ignition
Low-tension installation, e.g. using surface-discharge sparking plugs
Definition statement
This subclass/group covers:

Ignition installations having plugs with a high resistive, e.g. carbon, surface where a spark slowly propagates.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Sparking-plugs characterised by a discharge along a surface
Piezo-electric ignition; Electrostatic ignition
Definition statement
This subclass/group covers:

Ignition installation using a shock on a piezo-electrical crystal to trigger a spark.

Advancing or retarding ignition; Control therefor
Definition statement
This subclass/group covers:

Control of the ignition timing and arrangements therefore.

[N: combined with electronic control of other engine functions, e.g. fuel injection (in general F02D 37/02 )]
Definition statement
This subclass/group covers:

Conjoint control of ignition timing and other engine functions like control of fuel injection, e.g. control of fuel amount or air control, e.g. by throttle control.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Conjoint control of engines including ignition timing control
[N: using one central computing unit]
Definition statement
This subclass/group covers:

Ignition installations with an electronic control unit which is the main application of modern ignition control.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Control of ignition timing related to knocking
dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L 23/22 )
Definition statement
This subclass/group covers:

Ignition control of pinking/knocking i.e. undesired too early ignition which results in a shock against all the mechanical pieces (pistons, valves, rods, crankshaft) resulting in a very characteristic noise. This phenomenon arises mostly in acceleration with a warm engine. When knock is detected by a microphone or high frequency vibrations in pressure, ionic or light sensor, the ignition should be directly retarded and afterwards, slowly set back to where it belongs to be.

References relevant to classification in this group
This subclass/group does not cover:
Detection of knocking without engine control
Informative references
Attention is drawn to the following places, which may be of interest for search:
Engine control related to roughness or misfiring
Arrangements of distributors, circuit-makers or -breakers [N: e.g. of distributor and circuit-breaker combinations] or pick-up devices (advancing or retarding ignition or control therefor F02P 5/00; such devices per se, see the relevant classes of Section H, e.g. rotary switches H01H 19/00, contact-breakers, distributors H01R 39/00 , generators H02K)
Definition statement
This subclass/group covers:

Distributors, i.e. mechanical arrangements for distributing ignition signals as well as circuit makers and breakers, i.e. mechanical means for opening and closing ignition circuits. Furthermore it covers pickup-devices, i.e. means for detecting the current working phase or crank angle.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Rotary switches per se
Contact-breakers, distributors per se
of circuit-makers or -breakers, or pick-up devices adapted to sense particular points of the timing cycle
Definition statement
This subclass/group covers:

Pick-up devices which provide position information to the ignition timing control unit;Circuit-makers or -breakers.

Electromagnetic pick-up devices, [N: e.g. providing induced current in a coil]
Definition statement
This subclass/group covers:

Pick-up devices for detecting the engine position or cycle with electromagnetic means.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Means for retrieving engine position for fuel injection control
[N: Electronical verniers]
Definition statement
This subclass/group covers:

Means for generating higher frequency signals to increase the precision of crank (or cam) angle detection for ignition control.

Electric spark ignition control, not otherwise provided for
Definition statement
This subclass/group covers:

Electric control of sparks not provided for in previous groups, e.g. for controlling the intensity or length of the spark discharges.

[N: by weakening or suppression of sparks to limit the engine speed]
Definition statement
This subclass/group covers:

Systems for weakening or suppressing the spark for maximum speed control. Contains also engine speed limitation via ignition advance.

[N: by supplementary electrical discharge in the pre-ionised electrode interspace of the sparking plug, e.g. plasma jet ignition]
Definition statement
This subclass/group covers:

Plasma jet ignition plugs or similar arrangments.

Safety means for electric spark ignition, not otherwise provided for
Definition statement
This subclass/group covers:

Means for protecting the engine or associated parts using ignition elements.

Sparking plugs structurally combined with other parts of internal-combustion engines ([N: connection of ignition coil to spark plug connector F02P 3/02]; with fuel injectors F02M 57/06; [N: spark plug connectors per se H01T 13/04 to H01T 13/06; predominant aspects of sparking plug, see H01T 13/40 to H01T 13/44 ]; predominant aspects of the parts, see the relevant subclasses)
Definition statement
This subclass/group covers:

Combination of spark plugs with other elements of the engine, e.g. combination of a spark plug with a sensor.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Fuel injectors combined with spark plugs
Rod-type coils
Constructional details of ignition coils
Spark plug connectors per se
Special rules of classification within this group

Make the distinction with rod-type coils ("Stabspulen"), which are coils meant to be plugged on the plug connector and should be classified in F02P 3/02, and some very similar coils with electrodes really meant to be screwed in the cylinder head instead of the plug which should be classified in F02P 13/00

Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P 1/00 to F02P 13/00 [N: and combined with layout of ignition circuits (not combined F02B, F02C, F02G, F02K)]
Special rules of classification within this group

The type of ignition should be classified here while the way to generate and store the ignition energy should be classified in F02P 3/01 and F02P 3/05

Arrangements having two or more sparking plugs
Definition statement
This subclass/group covers:

Two or more spark plugs in one cylinder.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Multiple ignition simultaneously at different places in one cylinder or in several cylinders
Testing of ignition installations, e.g. in combination with adjusting (testing fuel injection apparatus F02M 65/00; testing ignition installations in general F23Q 23/00 ); Testing of ignition timing in compression-ignition engines
Definition statement
This subclass/group covers:

Testing and diagnosis of ignition installations in engines, e.g. for adjusting the ignition control or setup.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing of ignition installations in general
Testing of fuel injection apparatus
Testing of sparking plugs
Testing characteristics of the spark, ignition voltage or current (testing of sparking plugs H01T 13/60 )
Definition statement
This subclass/group covers:

Testing of ignition by evaluating the quality of the ignition using ionic current measurements or primary or secondary current evaluation.

Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
Definition statement
This subclass/group covers:

Ignition systems providing an incandescent heat source to induce or support ignition.

electric, e.g. layout of circuits of apparatus having glowing plugs
Definition statement
This subclass/group covers:

Circuits and control means for glow plug, e.g. supply of current to the glow plugs, control of activation and deactivation and monitoring of the glow plugs.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Glow plug per see
Direct use of flames or burners for ignition
Definition statement
This subclass/group covers:

Ignition system that directly uses flames or burners to cause ignition in internal combustion engines, e.g. flame glow plugs..

Informative references
Attention is drawn to the following places, which may be of interest for search:
Burners used to heat incandescent heat spot
Other physical ignition means, e.g. using laser rays
Definition statement
This subclass/group covers:

Ignition systems using laser ignition or high frequency electromagnetic waves causing plasmaignition or corona discharge ignition.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Plasma jet ignition
Lasers in general
[N: using electromagnetic microwaves]
Definition statement
This subclass/group covers:

Ignition systems generating high frequency waves in the microwave range for causing ignition.

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Last Modified: 10/11/2013