US2142082A - Ignition control system - Google Patents

Description

Jan. 3, 1939. F. c PEZZOLO 2,142,082

IGNITION CONTROL SYSTEM Filed Sept. 17, 1936 JNVEN TOR.

BY FRAn/cls C. PEZZOLO T 7 1- {Mj A TTORNEY Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE Claims.

The invention relates to an ignition system for internal combustion, or gas, engines having electrically operated starting motors.

A general object of the invention is to provide 5 an electrical ignition circuit which is arranged to be closed only while the engine is being turned over by the starting motor or is self-operating in a normal manner.

A more specific object is to provide for the engine control of the ignition circuit in the described manner by utilizing a vacuum which results from the actuation of the engine.

Another object is to provide anormally open ignition circuit which may not he accidentally left closed while the engine is not operating.

An added object is to provide for the automatic opening of the ignition circuit in the event that the engine should backfire or start a backward rotation from any cause.

A further object is to provide for manually opening the ignition circuit while the engine is operating, whereby to stop the engine.

Yet another object is to provide for an independent closing of the ignition circuit solely while the starting motor is energized.

The invention possesses other objects and features of advantage, some of which, with the foregoing will be set forth or be apparent in the following description of the invention, and in the an accompanying drawing in which,

Figure 1 is a diagrammatic presentation of th control system of my invention.

Figure 2 shows the system as applied in association with an internal combustion engine which is arranged to provide the motive power for a self-propelled vehicle.

As particularly illustrated in Figure 2, the ignition control system of present invention is shown as associated with an internal combustion engine 4 which is mounted in a fragmentarily shown vehicle wherein the operators compartment 6 is bounded in part by a floor 'l, a dash board 8, and an instrument board or panel 9, all provided in a suitable arrangement and relation therefor. It will be noted, however, that the present control system is applicable to other installations of internal combustion engines having electric ignition systems and electric starting 'motors.

A usual storage battery H is provided to supply operating energy to an engine-starting motor [2 through a starting circuit which includes a normally open switch l3 mounted on the vehicle floor l with a push button l4 thereof extending 55 into the compartment 6 for hand or foot actuation by the operator of the vehicle to close the starter circuit against the resistance of a compression spring IS. The circuit connections include a lead l6 from the battery II to terminal of the switch l3, a lead ll from the other terminal of the switch I 3 to a motor terminal, and ground connections I8 and 19 respectively. The starting motor I2 is mechanically connected to the engine crank shaft through suitable gearing and clutch connections in a housing 20 whereby it is arranged to produce operative actuations of the engine parts before the ignition is effective and the engine is selfoperating.

Current for the ignition circuit is also derived from the battery II, and said circuit includes a pressure-controlled switch 2|, 9. switch 22 which normally closes the ignition circuit thereat and is arranged for manual opening for a reason to be hereinafter brought out, a usual cam-operated timer switch 23, and the primary of a usual ignition coil 24. It will be understocdthat the ignition coil 24 is essentially a transformer, and that the secondary circuit thereof provides the energy at the engine spark plugs (not shown).

As shown in Figure 1, the switch 2| essentially comprises a movable contact arm 25 which is engageable with a fixed contact 26 for closing the ignition circuit thereat. The arm 25 is connected to and controlled by the movements of a resilient diaphragm 21 which provides one wall of a chamber 28 which is connected with the interior of the fuel intake manifold 29 of the engine by means of a pipe or tube 30.

The relations at the switch 2i are such that the switch arm 25 engages the contact 26 only when a sub-atmospheric pressure exists in the chamber 28 and manifold 29; the latter condition is understood to exist only while the engine is being turned over or actuated in its proper operative direction by the starting motor or while the engine is selfoperating. It will thus be understood that the ignition circuit is arranged to be open at the switch 2| while the engine is not operating; in this manner, the ignition circuit may not then be closed, or left closed, as frequently happens with manually operable ignition switches. As shown, the connections for the ignition circuit are provided by a lead 32 connecting the lead IE to the arm 25 of the switch 2|, a lead 33 from the contact 26 to one terminal of the switch 22, a lead 34 from the switch 22 to a terminal of the timer switch '23, a lead 35 from the other terminal of the switch 23 to the primary of the ignition coil 24, and a ground connection 36 from the coil 24. Recalling that the ignition circuit is open at the switch 2| unless a vacuum obtains in the engine manifold 29 by reason of the actuation of the engine in its normal rotative direction, itwill be noted that either a backfire or a reverse rotation of the engine will create a positive. pressure in the manifold and so open the ignition circuit at the pressure-controlled switch 2|. In 'this manner, ignition ceases under backfire and /or engine reversal conditions, and the engine may promptly come to rest for its restartingby energizing the starting motor l2.

It will now be noted that the switch 22 is mounted on the instrument board 9 and includes a movable contact arm 31 which norrnally engages a fixed contact 38 through the action of a tension spring 38. A push button 40 extends from the arm 31 and through the instrument board formanual engagement to displace the arm 31 to open the ignition circuit at the-switch 22 whenever the operating engine is to be stopped. It will be understood that the normally closed switch 22 is opened solely as a means to stop the operation of the engine by opening the ignition circuit therefor.

Since the ignition circuitwill be kept closed at the pressure-operated switch 2| by the suction in the manifold 29 as long as the engine is operating, a stopping of the engine requires that the ignition circuit must not be re-closed at the switch 22 until the engine movement is stopped, or substantially stopped.

In order-to avoid the necessity for manually pressing the push button 32 until the engine has stopped, means are preferably provided for auto matic operation to keep the ignition circuit open at the switch 22 until the engine has stopped and following a release of the push button by the operator.

As illustrated, the switch arm 31 is arranged to engage a contact 42 following its disposal out of contact with the contact 38, and the contact 42 is connected with one terminal of a terminal of a solenoid 43 having its other terminal grounded. The solenoid 43 encloses a fixed core 44 and the switch arm 31 carries an armature 4 5 opposite, and normally spaced from, an end of the core 44. In this manner, while the pressurecontrolled switch 2| is closed in,the described manner, the current which would normally flow through the ignition timer and coil is arranged to be shunted through the solenoid 43 to energize the same for retaining the arm 31 in its displaced position. It will be understood that the combination of the arm 3'|,and the contacts 38 and 42 constitutes a two-way switch.

Means are preferably provided for automatically closing the ignition system independently of the action of the switch 2| while, and only while, the starting motor circuit is energized, said means being particularly shown as comprising a normally open electro-magnetic switch 41 which. is operative to effect the independent closing of the ignition circuit while the starting motor is operative. The switch 41 is of the relay type and its solenoid 48 is connected in parallel with the motor l2 whereby the solenoid is energized only when the starting motor circuit is closed at the switch 3. A fixed contact 49 of the switch 41 is connected to the lead 32 by means of a branch lead 50, and the armature arm 5| of said switch is connected to the arm 31 of the switch 22 by means of a lead 52; in this manner, the closed 'relay circuit provides a shunt around the pressure-controlled switch 2| in the ignition circuit. It will be understood that it is immaterial if both of the switches 2| and 41 should be simultaneously closed, as might happen while the starting motor I2 is actuating the engine.

From the foregoing description taken in connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains. While I have described the features and the principles of operation of a structure which I now consider to be a preferred embodiment of my invention, I desire to have it understood that the showing is primarily illustrative, and that such changes may be made, when desired, as fall within the scope of the following claims.

I claim:

1. In combination, an internal combustion engine, an electric ignition circuit for said engine having a circuit-closing switch therein, means operative solely by the actuated engine to close said switch, means independent of said switch for manual actuation to open said ignition circuit for stopping the engine, and electro-magnetic means automatically operative to maintain said circuitopening means fully operative while the engine is stopping and said switch is closed.

2. In combination with an internal combustion engine having an electric ignition means, a source of electricity for said ignition means, an ignition circuit connecting the said source and the ignition means and including a normally open switch and a normally closed switch in series connection therein with the second switch operatively installed between the first switch and the ignition .means, mechanism automatically operative by the operative engine to close said ignition circuit at the first switch, manually controlled means to open the second switch while the engine is operating, and electro-magnetic means automatically operative to constantly-maintain the opened second switch in open condition solely while said mechanism is operative to 'close the ignition circuit.

3; In combination with an internal combustion engine having an electric ignition means, a source of electricity for operating said ignition means, an ignition circuit connecting the electric source and the ignition means and including a normally open switch and a normally closed switch in series connection therein with the second switch operatively installed between the first switch and the ignition means, a normally open branch of said circuit for providing'a shunt around the ignition means, mechanism automatically operative by the operating engine to close said ignition circuit at the first switch, manually controllable means to open the second switch and close the branch circuit, and means operable by the flow of current in said branch circuit when the same is closed to constantly maintain the second switch in open condition with respect to the first circuit while said mechanism is operative to close the circuit at the first switch.

4. In combination with an internal combustion engine having an electric ignition means, a source of electricity for operating said means, an ignition circuit connecting the electric source and the ignition means and including a normally open switch and a normally closed switch in series connection therein with the second switch operatively installed between the first switch and the ignition means, mechanism automatically operative by the operating engine to close said first switch, a normally open branch of said circuit for providing a shunt around solely the ignition means, a manually operative means to open the second switch and close the aforesaid branch of the circuit, an electric motor for energizing to actuate the engine at starting and having its energy circuit independent of said ignition circuit, a branch of the ignition circuit for providing a shunt around solely the first switch, a normally open switch in said last branch of the circuit, and means utilizing the energy circuit of the motor to close the last switch while said starting motor is energized.

5. In combination with an internal combustion engine, an ignition circuit having a normally open

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