US3158143A

US3158143A - Fxr rexucing poffer outfut

Info

Publication number: US3158143A
Authority: US
Publication date: 1964-11-24
Anticipated expiration: 1981-11-24

Description

Nov. 24, 1964 Filed Jul 25, 1962 R. c HEIDNER IGNITION SYSTEM INCLUDING THERMQSTATICALLY CONTROLLED MEANS FOR REDUCING POWER OUTPUT 2 Sheets-Sheet 1 INVEN TOR.

film/4,00 [llama 5e BY M024, M Q' M Nov. 24, 1964 R. c. HEIDNER 3,158,143

GNITION SYSTEM INCLUDING THERMOSTATICALLY CONTROLLED MEANS FOR REDUCING POWER OUTPUT Filed July 23, 1962 H I HW 2 Sheets-Sheet 2 United States Patent IGNllION SYSTEM INCLUDING THERMOSTATI- CALLY CONTROLLED MEANS FOR REDUCING POWER OUTI U'I Richard C. Heidner, lLibertyviiie, Ilh, assignor to Outboard Marine Corporation, Waukegan, ill, a corporation of Belaware Filed July 23, 1962, Ser. No. 211,715 6 Claims. (El. 123-148) The invention relates to ignition systems for spark ignition, multi-cylinder internal combustion engines and has for a principal object the provision of an ignition system which automatically functions to reduce the operating power level of the engine when the engine temperature exceeds a predetermined level. Generically, the invention contemplates an ignition system incorporating thermostatic means operable incident to overheating of the engine to interrupt the firing of at least one of the spark plugs while permitting continued sparking operation of at least another one of the spark plugs, thereby providing for continued operation of the engine at a reduced power level. As a result, if some heat removal can be etfected by the cooling system, the lesser amount of heat generated by operation at the reduced power level may permit reduction in the operating temperature oi the engine and continued operation at such reduced power level at temperatures below said predetermined level. In the case of outboard motors, where the cool ing water drains immediately from the engine block when the engine is stopped, it is often desirable to maintain the engine running at reduced speed in order to continue coolant flow so as to minimize the possibility of, freezing of the pistons to the cylinder walls. In any event, an immediate reduction in the power level will increase the time interval between initial overheating and substantial damage to the engine, thereby affording the operator opportunity to correct any malfunction or to take such other steps as may be desirable to prevent substantial damage to the engine.

More panticularly, the invention involves the associ tion of one or more spark plugs with a breaker, together with thermostatically operable means for preventing firing of the associated spark plugs when the engine temperature rises above the predetermined level, i.e., becomes overheated. One or more other spark plugs are arranged to fire independently of the operation of the thermostatic means. Accordingly, after operation of the thermostatic means, the engine will continue to 0p erate, but only at a reduced power output level.

Preferably, the thermostatic means is an electrical switch which is connected to the primary winding of the ignition coil. If desired, a warning light can also be electrically connected through the thermostatic switch in such manner as to apprise the user to an overheated engine condition. Other objects of the invention will become apparent by reference to the following description and the accompanying drawings of four embodiments of the invention.

In the drawings:

FIGURE 1 is a diagrammatic view of a battery-powered ignition circuit incorporating various of the features or" the invention;

FIGURE 2 is a diagrammatic view of a magnetopowered, ignition system similar to that shown in FIG- URE 1;

FIGURE 3 is an enlarged view of the cam means operating the breakers incorporated in the ignition systems shown in FIGURES 1 and 2;

FIGURE 4 is a diagrammatic view of another batterypowered ignition circuit incorporating various of the features of the invention;

FIGURE 5 is a diagrammatic view of a magnetopowered ignition system similar to that shown in FIG- URE 4; and

FIGURE 6 is a diagnammatic view of a modified electrical arrangement for preventing firing of less than all of the spark plugs when the engine is overheated.

The ignition system 11 shown in FIGURE 1 is specifically designed for a four cylinder, two stroke engine, in which the cylinders are fired in sequence at intervals relative to rotation of the crankshaft. The ignition system 11, as is conventional, includes a battery 13 connected through an ignition switch 15 to the primary winding 19 of an igntion coil 17 which also incorporates a secondary winding 21. The secondary winding 21 is selectively connectable to four spark plugs (shown diagrammatically at 23, 25, 27 and 29) by a distributor 31 mounted on a crankcraft indicated diagrammatically at 45. Firing of spark plugs is caused by opening of circuit breakers 33 and 35, two of which are provided for purposes which will become apparent. As is usual, condensers 49 and 51 are respectively connected in parallel with the breakers 33 and 35.

The breakers 33 and 35 are operated in the usual way by cam 43 which is carried on the diagrammatically illustrated cam shaft 45. The cam 43 includes opposed lobes 47 arranged for successively engaging the

operating pawls

39 and 41 of the respective breakers 33 and 35 so that, in co-operation with the distributor 31, the spark plugs are tired in succession. As is also common practice, operation of the distributor 31 and opening of the breakers is co-ordinated so that spark plugs 23 and 27 are fired incident to opening of the breaker 33, and so that spark plugs 25- and 29 are fired incident to opening of the breaker 35. The cylinders associated with spark plugs 23 and 27 should be operably balanced with respect to each other, so as to produce smooth operation when the engine is operating at reduced power, as will be explained.

Reduction of the operating power level, by one half in the embodiment shown in FEGURE 1, is afforded by thermostatically operable means for preventing firing of the spark plugs 25 and 29 associated with the breaker 35 when the engine is overheated. Operation of the breaker 33, and firing of the associated spark plugs 23 and 27, are not affected, whereby the engine continues to operate.

The spark plugs 25 and 29 can be prevented from firing by various electrical and mechanical means. In FIGURE 1, a thermostatically controlled switch means 37 is employed. The switch means 37 includes a normally closed switch 38a which is connected between, and in series with, the primary winding 19 and the breaker 35. When the engine becomes overheated, the switch 38a opens, and further opening of the breaker 35 by the cam 43 does not result in firing of the spark plugs 25 and 29.

Mechanical means can also be employed to prevent firing of the spark plugs 25 and 29. For instance, when the engine becomes overheated, a thermostatically operated mechanical interlock can be provided to retain the breaker 35 in open position. Thus, there would be no further firing of the spark plugs 25 and 29 while the engine is overheated.

Provision is also included for notifying the operator of the engine of an overheated engine condition by means of a signal which, in the disclosed embodiment, takes the form of a warning light 53 wired to a battery 13 through a normally open auxiliary switch 54 incorporated in the thermostatic switch means 37.

In FIGURE 2 there is illustrated a magneto-powered ignition system 61 which functions to produce the same result as the system 11 shown in FIGURE 1, when used in association with a relatively low speed engine, and

which is conventionally modified to accommodate the use of a magneto. Specifically, the primary winding 19 is a part of an ignition coil 17' which is incorporated in a conventional magneto and, at one end, is connected to the secondary winding 21' and to the breakers 33' and 35 as in FIGURE 1. At its other end, the primary winding is connectable through an ignition switch 15 to a ground. The ignition switch 15 also serves, when in the on position to connect the warning light 53' to a battery 63 through the auxiliary switch 54 in the thermostatic switch means 37.

FIGURES 4 and show, respectively, a batterypowered ignition system 65 and a magneto-powered system 67, for a two cylinder, internal combustion engine. The system 65 conventionally includes a battery 69 connected through an ignition switch 71 to a pair of ignition coils 73 and 75, each including

primary windings

77 and 79 and

secondary windings

81 and 83. The

secondary windings

81 and 83 are respectively connected to spark plugs indicated diagrammatically at 85 and 87. Respectively connected to each of the

primary windings

77 and 79 are breakers 89 and 91, which breakers are opened by a cam or cams (not shown) driven by the crankshaft so as to produce a spark at the desired time.

interposed between the breaker 89 and the primary winding 77 is a normally closed, thermostatically controlled switch means 95 which operates in the same manner as the switch means 37 shown in FIGURE 1, to open the circuit between the breaker 89 and the primary winding 77 when the temperature of the engine exceeds a predetermined level. As a result, further firing of the spark plug 85 incident to subsequent opening of the breaker 89 is prevented and continued operation of the engine is at a reduced power level.

The thermostatic switch means 95 also serves, when the engine is overheated, to connect a warning light 97 to the battery 69.

The magneto system 67,- shown in FIGURE 5, is intended for use with a relatively low speed engine and is identical to the system 65 shown in FIGURE 4, except as conventionally modified to accommodate the use of a pair of magnetos incorporating ignition coils 73' and 75. Specifically, one end of each of the primary windings 77' and 79 is grounded. The other ends of the primary coils 77 and 79', in addition to being connected to the respective windings 81' and 83' and the associated breakers 89 and 91', are connected to each other through an ignition switch 71'.

The ignition switch 71', as in the embodiment shown in FIGURE 2, also serves to connect a warning light 97 to a battery 99 through the thermostatic switch means 95' so that when the engine becomes overheated, the warning light circuit is closed to energize the light 97'.

FIGURE 6 shows a modification which is intended es pecially for use with relatively high speed engines employing magneto ignition circuits, such as shown in FIG- URES 2 and 5, but which can be employed in any of the disclosed systems for grounding or shorting the ignition coil. More specifically, with the modification shown in FIGURE 6, the thermostatic switch means 95 includes a normally open switch 96 connecting the primary winding 7'7 to a ground, thereby efifecting shorting out of the primary winding 77 and preventing firing of the associated spark plug when the engine is overheated. When the modification shown in FIGURE 6 is substituted in the circuit shown in FIGURE 2, energizing of the switch 95 to short out the single coil 17' prevents firing of all the spark plugs.

Although the ignition systems for a four cylinder engine have been shown with a single ignition coil and a distributor, a four cylinder system can be operated without a distributor and with an ignition coil for each breaker and associated spark plug in a manner similar to that shown with respect to the two cylinder embodiments illustrated in FIGURES 4 and 5. Likewise, if desired, the twin cylinder systems can be operated with only one ignition coil pro vided that a distributor co-ordinated with breaker operation is also employed. Moreover, the disclosed arrangements can be adapted for use with multi-cylinder engines having other than two or four cylinders and are also adaptable for use in four stroke engines, providing the timing is properly correlated.

Accessories, such as a search light or the like, can be connected to the disclosed ignition circuits at the point indicated by the numeral 101 in each of FIGURES 1, 2, 4 and 5.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. In an ignition system for spark ignition, multi= cylinder internal combustion engines including ignition means for firing of spark plugs associated with the cylinders, the improvement which comprises thermostatically controlled means operable incident to heating of the engine above a predetermined level for preventing the firing of at least one of said spark plugs while permitting continued firing of at least another one of the spark plugs.

2. An ignition system in accordance with claim 1 including a warning signal electrically connectable through said thermostatically controlled means to a source of electrical energy and in which said thermostatically controlled means includes switch means operable, incident to heating of said engine above said predetermined temperature level, to connect said warning signal to the source of electrical energy.

3. In an ignition system for a spark ignition, multicylinder internal combustion engine including at least one ignition coil including a primary winding and a secondary winding, two breakers with one of said breakers being connected to the primary winding of said one ignition coil, a spark plug associated with each of the cylinders, at least one and less than all of said spark plugs being connected to the secondary winding of said one ignition coil and being operably associated with said one breaker to produce a spark incident to opening of said one breaker, and means for opening said breakers to cause the production of sparks by said spark plugs, the improvement comprising thermostatically controlled switch means connected to the primary winding of said one ignition coil for preventing the firing of said spark plugs connected to the secondary winding of said one ignition coil and associated with said one breaker incident to opening of said one breaker when said engine is heated above a predetermined temperature level, and without afiecting the operation of said spark plugs which are not associated with said one breaker.

4. An ignition system in accordance with claim 3 wherein said thermostatically controlled switch means comprises a normally closed switch connected between, and in series with, said primary winding of said one ignition coil and said one breaker, said switch being opened incident to heating of said engine above a predetermined temperature level.

5. An ignition system in accordance with claim 3 wherein the spark plugs not associated with said one breaker are connected to the secondary winding of a second igni tion coil, and said thermostatically controlled switch means includes a normally open switch connected between said primary winding of said one ignition coil and a ground, said switch closing incident to heating of said engine above said predetermined temperature level so as to short out said one breaker.

6. In an ignition system for a spark ignition, multicylinder internal combustion engine, the combination of an ignition coil having a primary winding and a secondary winding,

a spark plug associated with one of the cylinders and connected to said secondary winding,

a breaker connected to said primary winding, said a 6 breaker being operable to cause the production of at least one other spark plug associated with another a spark at said spark plug, of the cylinders and operable independently of said thermostatic means operable to prevent firing of said thermostatic means.

spark plug incident to heating of said engine above a predetermined level, and 5 No references cited.

Claims

1. IN AN IGNITION SYSTEM FOR SPARK IGNITION, MULTICYLINDER INTERNAL COMBUSTION ENGINES INCLUDING IGNITION MEANS FOR FIRING OF SPARK PLUGS ASSOCIATED WITH THE CYLINDERS, THE IMPROVEMENT WHICH COMPRISES THERMOSTATICALLY CONTROLLED MEANS OPERABLE INCIDENT TO HEATING OF THE ENGINE ABOVE A PREDETERMINED LEVEL FOR PREVENTING THE FIRING OF AT LEAST ONE OF SAID SPARK PLUGS WHILE PERMITTING CONTINUED FIRING OF AT LEAST ANOTHER ONE OF THE SPARK PLUGS.