GB2190508A - Petrol ignition starting and diagnostic aid - Google Patents

Abstract

A self-contained coil ignition system including a coil 1, a battery 3 and spark electrodes 5 is capable of producing a spark independently from the magneto-generated spark for which an engine (not shown) may have been designed, thereby to permit starting and/or diagnosis of the engine. In use, the primary circuit of the coil (1) is arranged to be interrupted either by breaking contact between two plugs on respective leads (4a,4b), or by operating the contact breaker in the engine, and a spark at the electrodes (5) is observed through a window 9. The connections at a junction box (Figure 2 not shown) are then changed to allow the ignition pulse to be applied to the spark plug in the engine itself. The gap between the electrodes (5) is arranged to be about ten times as large as that at the engine spark plug to ensure firing in normal conditions. <IMAGE>

Description

SPECIFICATION Petrol ignition starting and diagnostic aid Well over 90% of motorized garden equipment and outboard motors are magneto operated. When they are properly maintained and stored they work very well indeed, and in the case of garden equipment are more convenient to use than electrically run motors, with theirtrailing flex problems.

The problem lies basically in the magneto characteristic, in that it runs best when the engine is turning over fast. Many women, and some older people, find it difficult to turn the engine overfast enough to start it. The problem is acerbated by conditions prevailing with most garden equipment after the winter "lay up" due to damp coils and dirty points.

The present invention seeks to overcome these difficulties by a portable attachment which will ensure that the engine fires, no matter how slowly the engine is turned over; or how damp the magneto has become.

If the cause of failure is the contact breaker points, the diagnostic side ofthe equipment will immediately pinpointthe fault.

There is nothing new in the use of dual ignition systems. There was one such system used in the early days of automobile engineering. The novelty in this invention lies in the fact that it is an applique self-contained coil ignition kitthatcan convert a machinethatwas originallydesigned as a magneto-operated equipment into a dual ignition system, which can easily and quickly be removed when no longer required; usually once the machine has started.

As the drain on the battery is small during the start up period,there is no need to incorporate a battery charging system. Modern batteries have such a high energy content there is sufficient capacity in the battery to last under normal usage for over a year. If the correct type of battery is used, it will not deteriorate if left in a partly discharged condition for that period.

Another novelty in the invention is that as it is a complete ignition system in itself it can be used as a diagnostic aid. It, first of all, confirms that the starting equipment itself is functioning. It then checks if the contact breaker and condensor on the engine are alright. Afurther connection from the equipmentto the engine provides a spark at the plug with 100% certainty.

If the engine still does not run after this test, it is not an electric problem and thefault must lie in the fuel system, which can easily be verified by introducing a petrol or explosive mixture into the cylinder and firing such a mixture with a spark generated by the invention.

An embodiment ofthe invention will now be described by way of example only, with reference to the attached drawings.

Figure 1 depicts the self-contained coil ignition system which consists of a 6v ignition coil, 1, screwed down to the base ofthe container case, 7a.

A6v'dry' alkaline cell battery, 3, is fastened buy a clip, 18, to the base ofthe case so that the cells can be replaced when exhausted. A condensor, 17 is connected across the spark electrode gap, 5. It is importantthatthis gap, which is at atmospheric pressure, is set about 10 times wider than the gap specified in engine spark plugs which is .025 inches usually.

An ignition system which could cause a spark in a sparking plug at atmospheric pressure could fail to provide a spark across the same gap at the pressure inside an engine cylinderwhen the gas is compressed by a piston.

The spark gap, 5, is located directly underthe inspection window, 9. As the system is a completely self-contained ignition system, it can demonstrate that it is functioning correctly at a distance away from any machine. The high tension lead from the coil, 2, is inserted into the plug socket, 2a, at the base of one of the spark gap electrodes. If now the wander leads, 4a and 4b, have the plug electrodes briefly broughtinto contact and then parted, a spark will be seen to pass across the gap, 5, when viewed through the inspection window, 9. This is because the plugs on the ends, 4a and 4b, have allowed a currentto build up in the primary winding ofthe ignition coil, 1.

A high voltage is induced by the secondarywinding and appears between the electrode, 2a, in the spark gap and the other electrode connection to the earth connection ofthe coil, 1 9b.

If a spark is seen when the connection of 4a is made and broken with 4b,theequipmentis functioning with sufficient energy to fire the engine.

The equipment can now be attached temporarilyto the handle of the machine by clip, 10.

The machine will have to be modified to allowthe equipmentto firethe engine atthe correcttime inthe compression cycle ofthe engine. This is done by meansofthejunction box seen in Figure 2. It isa plastic box which has 5 plug sockets set into it, suitably colour-coded with a single pole, double-throw switch, 15. The socket, 4c, will be coloured red and the socket, 4d, will be coloured black. The socket, 2b, will be yellow and this will be cross-connected inside the box to socket, 11 a, also coloured yellow.

The socket 1 2a will be connected on the underside to a lead taken from the high tension side of the engine magneto. A high tension lead from the engine spark plug will terminate in a yellow plug which will be inserted in 1 lea if the spark plug isto be sparked bythe equipment, or 12a if it isto be fired by the engine magneto.

Thewire in the engine magneto, 14,fromthe contact breaker points to the primary of the magneto coil is cut. One end is taken to the central contact of the STDP switch, 15. The other end is taken to the contact, 13, of the switch. The remaining contact is wired inside the box to the red socket, 4c.

The black socket, 4d, is wired to the metal bodywork of the engine - and is in fact the earth return forthe equipment low tension and high tension circuits.

The correct functioning of the machine contact breaker and condensor can now be checked.

Yellow plug on 2 is left in socket 2a.

Red plug, 4a, from equipment is plugged into red socket, 4c.

Blackplug,4b, is plugged intosocket4d.

The switch should be in such a position asto connect 15to4c.

If now the engine starting rope is pulled gently (no need for a big jerk) this will cause the machine contact points to open and if they are functioning a sparkwill be seen in the window, 9. The enginewill notfire atthis stage because the iead, 11, is not in socket 11 a. Theyellow plug from the equipment is now removed from socket 2a, and placed in yellow socket 2b, in the junction box.

The spark plug lead plug is inserted in the central yellow socket, 11 a. There can be absolute certainty that a spark will pass between the electrode ofthe sparking plug when the starting rope is gently pulled; even at the high pressure of gas prevailing in the cylinder. Ifthe engine does notfire when the starting rope is pulledthere is no ignition fault buta fuel problem is indicated. This can be verified by introducing petrol into the cylinder or using aproprietary starting mixture, injected into the air inlet. The engine will almost certainly start; but if it runs only for a few seconds, this confirms the diagnosisthat it is a fuel failure.

In most cases, the engine will fire when the starting rope is given even a gentle pull. When the engine is running evenly, the switch, 15, should be moved to the opposite contact, that is connecting 14 to 13, which restores the interrupted connection in the magneto. Atthe sametime, with the minimum delay, the plug in 1 1a should be inserted inthesocket 12a.

The machine is now working on its own magneto system. If the engine continues to run, the equipment can now be removed from the machine by taking plugs 4a, 4b and 2 from their sockets, and unclipping the equipmentfrom the machine. If, however, the engine stops when the switch and plugs have transferredthe operation to the magneto, then the switch and plugs should be replaced in their original positions and the machine started again. If it will only function with the equipment generating the sparkthere is afault in the magneto coil, and this will have to be renewed or repaired.

In an emergency, the machine can be operated on the equipment but the battery system will be exhausted after approximately one hour, because it is only designed for intermittent use during diagnostic procedures, or starting up periods.

Claims (10)

1. Aseif-containedcoil ignition system comprising an ignition coil, battery, condensor, sparkgap, and a system of plugswhichwill allowa spark to pass between spark electrodes placed ata suitably wide distance apartthe spark shall be capable of being viewed through an inspection window.

2. The equipment described in Claim 1 shall all be mounted in a portable case capable of being attached to any machine, so as to provide a dual ignition system ,or a machine which in the first instance was designed to operate by magneto only.

3. The self-contained self ignition system described in Claims 1 and 2 can operate completely independently from the ignition system ofthe machinetowhich it is attached; thus providing a complete diagnostic test equipmentforthe ignition system installed in any machine.

4. The equipment described in Claims 1 and 2will provide an inherently easier starting system because it is coil ignition ratherthan magneto operated. It converts the machine to coil ignition during the difficult starting period; but still allows the machine to run on its own magneto to save battery drain.

5. Any machine to which the equipment has been attached and has also been modified by a suitable junction box, will allow connections to be made quickly and easilytothe machine from the equipment. A single equipment can be used to diagnose faults oras a starting aid in any number of machines so modified.

6. There is no need to arrange a charging system forthe equipment battery because if usedfor diagnostic purposes and a starting aid only the batteries provided in the system will last over one year and can easily be renewed.

7. The equipment described in Claims 1 and 2 will be capable of providing a stand-by ignition system in the case of a complete failure of the engine'sown ignition system, provided only that the contact breaker timing device is working on the engine.

8. The equipment described in Claims 1 and 2 with a suitably designed junction box and connections can be usedto diagnosefaults in an engine fitted with coil ignition, as is the case in most modern cars.

9. An equipment as described in Claims 1 and 2 and a junction box as used in Claim 8, can be used to provide an emergency ignition system for a coil ignition engine. It would be necessary to isolate the starting and lighting circuits of the equipment. In this case it will only be possible to run the engine for 15-20 minutes on the equipment battery.

10. A diagnostic equipment and starting aid which is substantially as hereinbefore described and iilustrated with reference to the accompanying drawings.