US1375736A

US1375736A - Ignition system

Info

Publication number: US1375736A
Application number: US203314A
Authority: US
Inventors: Elmer H Schwarz
Original assignee: Dayton Engineering Laboratories Co
Current assignee: Dayton Engineering Laboratories Co
Priority date: 1917-11-22
Filing date: 1917-11-22
Publication date: 1921-04-26
Anticipated expiration: 1938-04-26

Description

E. H. SCHWA'RZ. IGNITION SYSTEM. APPLICATION FILED NOV. 22, 1917.

Patented Apr. 26, 1921.

umtrao stares ra'rau'r orries.

ELMER H. SCHWARZ, 01F GLEN ROCK, NEW JERSEY, ASSIGNDR TO THE DAYTON ENGINEERING LABORATORIES COMPANY, A CORPORATION OF OHIO.

IGNITION SYSTEM.

unit type where separate motor and generator units are employed.

In systems of this character where the ignition current is supplied by storage bat-- teries in conjunction with a charging generator, it is considered advisable to protect the ignition circuit against overload at low engine speed, particularly when the engine comes to rest with the contact points of the ignition breaker together. If the ignition switch is not opened under such conditions,

1 an abnormal current will flow from the storage battery throughthe primary circuit of the induction coil. This will rapidly exhaust the battery :and endanger, if not burn out, the primary coil. My invention provides improved means for properly safeguarding the ignition circuit and storage batteries.

I will now describe the means embodying my invention illustrated in the accompanying drawings, and will thereafter point out the novel features in the claims.

Figure 1 is a wiring diagram showing the circuit connections of a starting, lighting and ignition system of the two-unit type to which my invention has been applied;

Fig. 2 shows the invention similarly applied to a single-unit system; and

Fig. 3 shows a modification of the'invention which may be applied to either a single- "or a two-unit system. i

Referring to Fig. 1, the motor starting Specification of Letters Patent.

to the negative side of the battery 1. The clos ng of the starting switch 7 rotates the engine which is of the internal-combustion type and n'ot'self-starting. After the en gine has started under its own power, the starting switch is released and is opened by a spring as is usually the case. The generator is of the shunt type, either self-excited as shown or excited from the storage battery, and consists of the armature 8 and the shunt field 9. As soon as the engine 1s started the generator begins to pick up, that is, a voltage is established across the armature 8 which increases with the-speed of the engine, and which, when it reaches a predetermined value, .causes the automatic swltch 10 to close and to establish connections between the generator and the storage battery. The automatic switch 10 is magnetically 0 erated and controlled by a shunt a series-coil 12, which act upon a the 1IOI1 core 13 which attracts the movable;

coil 11 an armature 14 to which the movable contact 10 of the switch is attached. The shunt coil 11 is connected across the armature 8 and its current is therefore proportional to 'the voltage-set up in said armature. The

shunt coil 11 therefore controls the closure of the switch 10 at a predetermined value of the generator voltage. When the switch 10 closes, the generator circuit is established as follows:

From the positive brush of-thegenerator, throughth wire 2 to the positive side of the storage battery 1, through said battery to the negative side, through the wire 15, through the contacts 10* and 10 of automatic switch 10, the series coil 12 of said switch, and through the wire 16 to the negative side of the generator armature 8; The generator is now charging the storage battery, since the automatic switch 10 is so ads justed that it will not close until the generator voltage exceeds that of the battery. The series coil 12 of the automatic switch is so connected that the magnetism set up thereby is in the same direction as that of the shunt coil 11 when the generator is charging the storage battery. If, however, the speed of the generator is so reduced that its voltage falls below that of the storage battery, the generator armature current is then reversed with a similar reversal of current through the series coil 12. The magnetism set up by this coil will then oppose Patented Apr. 26,1921. Application filed November 22, 1917. Serial No. 203,314.

that of shunt coil 11, and the

contacts

10 and 10 of the automatic switch 10 will then open and cut off the generator from the storage battery. The construction and operation of an automatic switch of this type have long been well known, and any of the forms of construction of said switch are applicable to my systenr.

It remains to trace out the ignition circuit, which is as follows: from the positive side of the generator, through the wires 3 and 17, through the primary coil of the induction coil 18, the ignition breaker 19, the ignition switch 20, the

wires

21 and 22, the series coil 12 of the automatic switch 10, and the wire 16 to the negative side of the generator. It will therefore be seen that the ignition circuit is connected directly across the terminals of the armature 8 of the gen era-tor, and on the inside of the automatic switch 10, so that if the automatic switch is open the ignition current will be pro vided only by the generator, and the voltage of the ignition circuit will in that event be proportional to the speed of the generator. 'lhis, therefore, guarantees regulation of and protection to the ignition circuit at. low speeds, since the voltage will be decreased in proportion to the decreased resistance or reluctance of the ignition circuit at low speeds. Also, since the battery is cut off from the ignition circuit at thistime, there will be no danger of exhausting the batteries.

It may be desirable in starting the engine to supply the ignition current from the battery sinceat this time it is advantageous, particularly at the low speed at which the engine rotates, to have a strong current passing through the ignition circuit. To this end 1 may provide an extra contact 23, on the-starting switch 7, which establishes a. momentary short circuit across the contacts 10'' and 10 of automatic switch 10, thus supplying the ignition circuit with current from the storage battery 1 at starting. an arrangement, it will be observed that the generator will also be connected across the torage battery, through the starting switch 7 and the auxiliary contact 23, and the generator, on account of its low speed, will tend to act as a motor and to receive current from the storage battery. Due to the high. resistance of the armature 8 of the generator, this current will be small in amount and it will be used for a short period of time only, and the effect therefore on the storage battery will be almost negligible. Means are also provided for placing the short circuit around the

contacts

10 and 10" of automatic switch 10, in case, for any reason, it is necessary to start the engine by the hand crank I 24. This means consists of'a pivoted movable switch member 25, which is engaged by the hand crank'member 24, when the crank With such handle is pushed in to engage the clutch 24;? on the outer end of the crank shaft, as shown in ig. 1. The movable contact 25 will then engage the stationary contact 26, which, as will be seen, places a short circuit around the contacts of the automatic switch 10 through a ground connection, and thus the ignition circuit is supplied directly from the storage battery and the engine is started by hand. A spring 27 opens the

contacts

25 and 26 when the crank handle 24- is released.

Fig. 2 is similar to Fig. 1, except that the novel ignition circuit connections are applied to a, single-unit system where the starting motor acts also as a generator to charge the storage battery after a predetermined speed has been reached and the automatic, switch is closed. In this case, 1 have shown the dynamo-electrimmachine provided with a shunt-winding 9 and a series-winding 9, so connected that they act accumulatively when the dynamo-electric-machine is acting as a motor, and differentially when acting as a generator, as a means of current regulation for varying speeds of the generator. Different forms of windings and of regulation might be used, however, and 1 do not wish to limit the invention in this respect. Where a single machine performs the functions of both a generator and a motor, it will be observed that the starting switch 7 will, when v closed, place a short circuit around the contacts 10* and 10 of the automatic switch 10. In this case, therefore, it is unnecessary to provide theextra contact on the starting switch as in Fig. 1. It should be understood that I prefer to provide the hand crank 24 with means for establishing a short circuit arorrz'id the automatic switch 10in Fig. 2, similariy to 1 ig. 1.

1n 3 I have'shown a modification of my invention, in which the ignition circuit is connected directly across the battery 1, and in which I rely chiefly on the alarm de- Vice 28 to protect the ignition circuit. The alarm device 28 is connected to automatic switch contact 10 and between the ignition switch 20 and the ignition timer 19. Of

course, in this case, the signaling device 28 is chiefly advantageous if the ignition breaker contacts of the breaker 19 happen to be closed when the engine stalls but it is of course an advantage to be reminded, in any event, thatthe ignition switch 20 should be opened. The connection shown, however, has an added advantage in notifying the driver when the automatic switch opens and the generator is no longer charging the storage battery. The engine might be running very slowly at this time and the condition of the battery might be such that it would be desirable to speed up the engine so as to close the automatic switch 10 and begin to charge the storage battery.

I may add to the ignition circuit, in Fig. 3,

- sistance in the ignition circuit constitutes no part of my invention, but is the subject matter of U. S. Patent 1,223,180 to Charles F. Kettering, dated April 17, 1917. The generator of Fig. 3 can either bethe generating unit of a two-unit system such as illustrated in Fig. 1, or the dynamo-electricmachine of a single-unit system such as is illustrated in Fig. 2. The connections would be the same in either case, being applied to [charging the same; electrical connections with-the battery and place and to the the generator in the first in the second dynamo-electric-machine place.

While the forms of mechanisms herein shown and described constitute preferred forms of embodiments of the invention, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

- than the voltage of What I claim is as follows: 1. In an electric charging system, the combination with a battery, a generator for charging said battery; circuit connections between the battery and generator, including an automatic switch for disconnecting the generator from the battery when the voltage of the generator is lower than the voltage of the battery; and a signaling device, operable upon the opening of said automatic switch,,said device, when operable, being arranged in series between the battery and generator.

2. In an electric charging system, the combination with a battery, a generator for charging said battery; circuit connections between the battery 1 and generator, including an automatic switch for disconnecting the generator from the battery when the voltage of the generator is lower signaling device which is connected across the contacts of said automatic switch,

series between the battery and generator.

3. In an electric charging system, the

, combination with a battery, a generator for charging said battery; clrcuit connections the battery; and a said. .device, when operable, being arranged. in

voltage of the generator is lower than the voltage of the battery; and a signaling device which is operable when the batteryvoltage exceeds the generator voltage by a predetermined amount, said device, when operable, being arranged in series between the battery and generator.

.4. In an electric charging system, the combination with a battery, a generator for charging said battery and circuit connections between the battery and the generator; of an independent circuit including a signaling device operable upon a predetermined generator speed, said signal device,

when operable, being arranged in series between the battery and generator.

5. In an electrical system, the combination with a battery and a generator for ignition devices having generator; a manually operable switch to control the ignition circuit; and an electrical signaling device operable after the generator reaches a predetermined low speed, said device being operative only as long as the ignition switch remains closed.

6. In an electrical system, the combination with a battery; of a generator for charging the battery; ignition devices n'ormally connected with the generator; manual means for connecting the ignition devices and battery for engine starting purposes; and automatic means for connecting the generator and battery for charging purposes upon attainment of a predetermined generator speed, said automatic means operable to disconnect the generator and battery while permitting the ignition devices to remain connected to the generator.

7. In an electrical system, the combination with abattery and a generator for charging the same; ignition devices having electrical connections with the battery; a switch for controlling the ignition circuit, automatic means for disconnecting the battery from the generator when the voltage of the generator is lower than the voltage of the battery; and a signaling device-operable after the battery voltage exceeds the generator voltage,

tive only as long as the ignition switch remains closed.

In'testimony whereof I afiix my signature in presence of two witness.

ELMER H. SCHWARZ. Witnesses: A

FREDERICK J. HARDMAN, WARREN SCHNIEDING.

said device being opera-r