US3384062A - Emergency cutoff switch for use on internal combustion engine - Google Patents

Description

y 1968 K. 5. BOYER EMERGENCY CUTOFF SWITCH FOR USE ON INTERNAL COMBUSTION ENGINE Filed May 2, 1966 SYSTIFM United States Patent 3,384,062 EMERGENCY CUTOFF SWITCH FOR USE ON INTERNAL COMBUSTION ENGINE Kenneth G. Boyer, 707 Country Club Road, Casper, Wyo. 82601 Filed May 2, 1966, Ser. No. 547,005 1 Claim. (Cl. 123-198) ABSTRACT OF THE DISCLOSURE An automatic temperature and oil pressure responsive safety system for cutting off the ignition system of an internal combustion engine. The safety system includesa relay having a pair of normally closed contacts connected in series between the ignition switch and the ignition system. The coil of the relay is connected to the electrical system supplying the engine through a normally closed push button cutout switch and the parallel combination'of a temperature responsive transducer and an oil responsive transducer. The transducers are effective to energize the relay in response to a predetermined maximum temperature and/or a predetermined minimum oil pressure.

This invention generally relates to a new and useful electrical cutoff system for use in any combustion engine which employs electricity for ignition purposes.

More particularly the invention relates to internal combustion engines and diesels or the like and it incorporates therein a cutoff system which will terminate engine ope-ration when the existence of abnormal conditions are sensed. The invention provides a cutoff circuit which is electrically actuable or energizable so as to interrupt engine operation when the existence of any one or more conditions prevail in the associated combustion engine equipment. In the disclosed construction of the device the cutoff circuit is associated with an internal combustion diesel engine, this, however, is intended to be merely exemplary and not limiting. The circuit includes two transducers which are respectively responsive to temperature and oil pressure, and which operates in conjunction with a solenoid to terminate the operation of the combustion engine when certain predetermined critical oil pressure and operating temperatures are exceeded.

A switch is included in the device to enable the operator of the internal combustion engine to bypass the automatic cutoff circuit when the engine is ignited either at low temperatures or under other abnormal conditions. This bypassing device is specifically useful when the invention is incorporated in a diesel engine which normally is cranked to commence initial operation. The bypassing device will assure that the solenoid switch located on the fuel pump of diesel engines has the proper operating current before the cranking operation begins, otherwise the diesel engine will fail to initially ignite.

Presently existing systems have dashboard lights to indicate an abnormal condition in an internal combustion engine, however, no means are presently available to autoatically terminate the operation thereof before this condition creates an irreparable situation. The subject invention can conveniently be incorporated in existing indicating systems, since generally these systems have pressure and temperature transducers as standard items.

It is a primary object of this invention to provide a cutoff system for internal combustion engines so that when specific abnormal conditions are sensed, the engine will automatically terminate its operation.

It is another object of-this invention to provide a cutoff system which is readily incorporated in presently existing internal combustion engines, so as to make the safe operation thereof automatic.

These and other objects of the present invention will become obvious by reference to the following description and accompanying drawings.

FIGURE 1 is an enlarged sectional view of the solenoid cutoff means.

FIGURE 2 is an enlarged sectional view of the bypass means.

FIGURE 3 is a diagrammatic view of the complete system, as it is incorporated in an ignition system.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 10 designates an ignition system as is generally used in internal combustion engines. An oil pressure transducer 12 is provided for grounding the ignition system when a minimum oil pressure is reached. In order to assure proper operation of an internal combustion engine, it is necessary that a minimum oil pressure be maintained within the engine. If this pressure falls below a certain minimum and is allowed to continue, detrimental effects will arise that will be harmful to future engine operation. The oil pressure transducer 12 is set to ground the ignition circuit when the oil pressure reaches a minimum of 8 to 10 pounds per square inch. The device comprising the present invention is also adapted to ground the ignition circuit when a high temperature is sensed by the temperature transducer 14. This will protect the internal combustion en ine from operating at extremely high temperatures that may be detrimental to its operation. The temperature transducer 14, may be set to shut down the engine when the temperature reaches 200 to 210 degrees. It is noted that either condition wiil terminate the engine operation when the predetermined limits are reached.

Referring specifically to FIGURES l to 3, a relay 15 is provided; it is composed of a solenoid 16 adapted to actuate a contact member of electrically conductive material which has a contact plate 20 mounted on one end thereof. The contact plate 20 is adapted to engage a contact plate 22 mounted on another contact member of electrically conductive material as indicated at 24. The contact plates 20 and 22 are normally closed, and are kept in this position by a spring-like contact member 26. The spring contact is mounted on another member of electrically conductive material as indicated at 28. Member 28 is connected through terminal 30 to a conductor 32, which is attached to one terminal 34 of an ignition switch 36, controlled through the ignition key 38. The other terminal of the ignition switch 36, is connected to a battery 42.

One terminal of the core of solenoid 16 is connected to terminal 30. The other terminal of the core 16 is connected through conductor 44 and dielectric hole 46, to terminal 48. This terminal 48 is connected to bypass switch 50 by conductor 49, the operation of which is explained infra. The member 24 of electrically conductive material is connected to terminal 52, which in turn is connected to ignition system 10, via conductor 54.

FIGURE 2 specifically displays a diagrammatic side view of bypass switch 50. It is shown merely as exemplary and is not intended to be limiting. The switch 50 is used to bypass the automatic cutoff system, when the engine is ignited under some abnormal condition as previously described. It is composed of a forward biased spring member 56 which maintains the automatic cutoff system in operation, unless it is specifically desired to be eliminated. This can be accomplished by manually dcpressing button 58, which moves a cylindrical sliding body 60, connected to button 58 through the rod 62. The contacts 64 and 65 are mounted on a piece of dielectric material 68, and are maintained in electrical contact through a plate of conducting material 70. The electrical contact is further secured and enhanced by a spring means 72 which is located on cylindrical sliding body 60. The bypass switch 50 can be secured to the dash board 74 of an automobile or any other convenient location to the operation of the system. A thread mount '76 is provided for this application.

In operation, when the ignition system is first started under an abnormal condition, such as low temperature, the button 58 of bypass switch 50 is depressed to insure that the engine will ignite. After the engine has ignited and is running properly the bypass switch 50 is allowed to assume its normal position, as shown in FIGURE 2. Assuming for purposes of this operational disclosure, a low oil pressure (e.g., below 8 to 10 p.s.i.) is sensed by oil pressure transducer 12. This completes the cutoif circuit through the following components: from oil pressure transducer 12, via wire 78 to contact 54, through con tact plate 70 to contact 66, via wire 49 to contact 48, through wire 44 to the solenoid core 16. This energizes the solenoid core 16, which opens the normally closed contacts 20 and 22, thereby interrupting the current flow to the ignition system 10. This automatically terminates the operation of the internal combustion engine. This automatic cutoff system, by so shutting down the operation, alleviates any damage which may be incurred from operating the internal combustion engine with an internal detrimental condition.

It can be readily ascertained that the system Will perate in exactly the same manner for a high temperature condition which may be sensed by the temperature transducer 14. The transducers are connected in series via wire 80, so that either condition will automatically cut oif the operation of the engine.

From the foregoing, the construction and advantages of this emergency cutoff system are readily apparent and further description is believed to be unnecessary. However, since numerous modifications will readily occur to those skilled in the art, after a consideration of the foregoing specification and accompanying drawings, it is not intended to limit the invention to the precise embodiment shown and described, but all suitable modifications and equivalences may be readily resorted to if desired.

What is claimed as new is as follows.

1. In an internal combustion engine having an ignition switch and an ignition system, a temperature and oil pressure responsive safety system for automatically cutting off said engine in response to an abnormal temperature or oil pressure comprising:

a relay having a pair of normally closed contacts and an energizable coil for opening said contacts,

means for connecting said pair of normally closed contacts in series between said ignition switch and said ignition system,

a spring-loaded, normally closed, push-button cutout switch for disabling said safety system,

an oil pressure transducer having a first terminal, said oil pressure transducer being elfective to ground said first terminal in response to a predetermined minimum pressure within said engine,

temperature transducer having a second terminal, said temperature transducer being responsive to a predetermined maximum engine temperature to ground said second terminal, and

means for connecting said first and second terminals,

said spring-loaded normally closed push-button switch and said energizable coil in series to the junction of said ignition switch and said pair of normally closed contacts.

References Cited UNITED STATES PATENTS 1,770,264 7/1930 Eslinger 123146.5 1,920,694 8/1933 Hancock 123-1465 2,162,174 6/1939 Jones 123146.5 2,317,062 4/1943 Jervis 123146.5 X 2,358,729 9/1944 Murphy 123-146.5

FOREIGN PATENTS 279,551 10/ 1927 Great Britain.

WENDELL E. BURNS, Primary Examiner.

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