ELECTRIC STARTING AND LIGHTING OPERATION
Current from the generator passes through an ammeter and this meter shows the current being supplied to the battery and the lights, or to the battery only when no lights are in operation.
Starting Motor.—The starting motor is provided with a square shaft and carries a pinion which can be moved horizontally on this shaft. This pinion meshes directly with teeth cut on the flywheel.
The starting pedal located at the driver’s seat connects through linkage to fork which shifts the link on the square shaft of the motor. The same foot pedal linkage operates the starting switch. Normally a spring holds the motor pinion out of mesh with the flywheel teeth, and also holds the starting switch in an “off” position.
Operation of the Starter.—Depressing the starter, one pedal operates the starting switch and makes a preliminary contact which connects the starting motor to the storage battery through a resistance located inside of the starting switch. This resistance permits a small amount of current to pass through the starting motor, causing its armatures to rotate at relatively slow speed. This slow rotation insures proper meshing of the pinion and flywheel teeth when they are brought into engagement. Depressing the foot pedal also shifts the pinion on the square shaft of the motor so as to bring it into contact with the teeth on the flywheel.
When the pinion is in full mesh with the teeth on the fly, the moving contact in the starting switch has traveled to a position where the resistance is cut out of the circuit, connecting the storage battery directly to the starting motor. The starting motor will then spin the gas motor.
Starting.—First see that the necessary adjustments have been made, then depress the starting foot pedal as far as it will go and hold it firmly in place until the gas motor starts. The instant the gas motor begins firing the foot pedal should be released. The starting pedal should be pressed as far as it will go without any pausing on the downward stroke.
[Fig. 90] shows diagram of operation and wiring of the Bijur electrical system used on Jeffery 4-cylinder car.
If the pinion and flywheel teeth do not mesh properly do not hold the starting pedal down, release it and after a few seconds pause, depress the pedal again.
If the gas motor does not start firing promptly after spinning it with the electric motor, do not continue to spin it, but see that the proper adjustments for starting have been made and that there is gasoline in the carburetor, and that the ignition is in working order.
Continued spinning of the gas motor by the electric motor will not damage the electrical equipment but constitutes a useless drain on the storage battery and should be avoided.
Wiring.—[Fig. 90] shows the circuits for all electric appliances on the Jeffrey-4 car. The various units are wired on the two-wire system. The “out of focus” filaments in the head lamp bulbs are wired on the three-wire system, the chassis acting as a neutral wire, one side of the “out of focus” filament being grounded in the head lamps. The “in focus” filaments are on the two-wire system.
The dash lamp is on the tail lamp circuit and is so arranged that these two lamps are always in operation when any combination of head lamp filaments are in use.
Fuse Circuits.—Each head lamp is separately fused, the current for both filaments in each head lamp bulb passing through one fuse.
| GROUND TO OIL PIPE | ||||||
| GROUNDED TO INSTRUMENT ASSEMBLY | ||||||
| RIGHT HEAD LIGHT | GENERATOR | |||||
| DASH LAMP | ||||||
| SWITCH | INDICATOR | |||||
| CYLINDERS 1 2 3 4 | CONNECTIONS THROUGH SWITCHIN “DIM” POSITION | |||||
| FUSE AND JUNCTION BLOCK | ||||||
| HORN | CONNECTIONS THROUGH SWITCHIN “ON” POSITION | |||||
| MAGNETO | HORN BUTTON | |||||
| MOTOR | STARTING SWITCH | BATTERY | WIRING FOR 6-CYLINDER MODEL661 IS THE SAME AS FOR 4-CYLINDERMODEL 462, EXCEPT FOR HIGH TENSIONLEADS BETWEEN MAGNETOAND SPARK PLUGS. | |||
| LEFT HEAD LIGHT | ||||||
| NOTE:—DOTTED LINES INDICATE PERMANENTCONNECTIONS BETWEEN FUSECABINET, DASH LAMP, CURRENT INDICATORAND SWITCH. CONNECTIONS AS SHOWNFACING FUSE CABINET. | SWITCH GROUNDED | REAR | ||||
Fig. 90. Wiring Diagram—Jeffrey-Four
Separate fuses are provided for the electric horn circuit and for the rear lamp circuit. The push button for operating the electric horn is mounted on the center of the steering post.
Ground Fuse.—A fuse is located in the ground circuit between the lamp controller and the magneto top to ground.
Fig. 91. Hydrometer Syringe
Lamp Controller.—A pair of wires from the terminals of the storage battery connect to the five position lamp controller. All lighting circuits connected to this controller which may be locked in any of the five positions.
Oiling should be practiced regularly every two weeks or every five hundred miles. Two or three drops of thin neutral oil should be put in each of the two oilers of the motor and in each of the two oilers of the generator. Do not flood the bearings with oil.
At the same time the starting motor shaft should be oiled. An oil hole is provided in the top of the starting motor gear case and about ten drops of cylinder oil should be used.
[Fig. 91] shows a hydrometer syringe used for determining the specific gravity or density of the solutions in the battery cells.
To take specific gravity readings unscrew the filler or vent plug and insert the tube into the cell and release bulb slowly to draw the acid solution into the chamber until the hydrometer floats. The enlarged graduated stem shows a reading of 1.280 at the point where it emerges from the solution. After testing, the solution must be returned to the cell from which it was taken. Specific readings above 1200 show the battery more than half charged.
Gravity below 1.150 indicates battery completely discharged or run down.
Should the gravity fall below 1.150 the gas motor should be given a long run to restore the battery.
CHAPTER XXIV
NORTH EAST STARTER SYSTEM USED ON DODGE BROTHERS’ CARS
The North East starter system shown in [Fig. 911⁄2] comprises the North East Model G starter-generator and the combined starting switch and reverse current cut-out. This equipment serves to start the engine and provide current for the lamps and other electrical accessories as well as for the ignition system. The battery as the source of current while the engine is not in operation or is running slowly; but at all engine speeds above 350 R. P. M. the starter-generator supplies current for the entire electrical system.
Wiring.—In the accompanying wiring diagrams the starting circuit is represented by the very heavy cables; the charging circuit, where it does not coincide with the starting circuit, by the cables of medium weight, and the lighting and the ignition circuits by the light cables. As will be seen from the diagrams, the starting circuit extends from the positive terminal of the battery to the starting switch, and thence, when the switch is closed, through the starter-generator armature and field coils back to the negative terminal of the battery by way of the grounded negative starter-generator terminal, the car frame, and the battery ground connections. The charging circuit is identical with the starting circuit except at the starting switch, where instead of passing from one switch terminal to the other through the switch contactor it extends through a parallel path which includes the reverse current cut-out and the charging indicator. The cable leading to the lighting and ignition switch is attached to the positive terminal of the indicator. From this switch the lighting and the ignition circuits become distinct, and each, after passing through its proper course, reaches the car frame and returns through it to the source of supply.
| Charging Indicator | Lighting & Ignition Switch | Dash Lamp | |||||||
| Horn | |||||||||
| Head Lamp | GroundTail Lamp | ||||||||
| Ground | Horn Button | Starting Switch and Reverse Current Cut-out | |||||||
| Ground | Ground Connection | Ground | |||||||
| Head Lamp | |||||||||
| Battery | |||||||||
| Ground | Starter-Generator | Ground Connection | |||||||
Fig. 911⁄2. Dodge Wiring Diagram
Without exception all the connections of the starting and lighting system must be made as indicated in this diagram if entirely satisfactory results are to be obtained from the equipment.
Starter-Generator ([Fig. 92]).—The starter-generator is mounted on the left side of the engine by means of an adjustable support and a clamping strap. It runs at three times engine speed, operating directly from the crank shaft through a silent chain drive. Being a single unit machine, it employs but one armature with only one commutator, one set of field windings and one set of brushes for the performance of all of its functions both as a starter and as a generator.
While starting the engine it acts as a cumulatively compounded motor; but while serving as a generator it operates as a differentially compounded machine with its output positively controlled through the agency of a Third Brush Regulating system, supplemented by the differential influence of the series field upon the shunt field.
The machine is designed for 12 volt service and, when driven by the engine, normally begins to deliver current to the battery as soon as the car speed is brought up to approximately 10 miles per hour. From this point on, the charging rate rises rapidly with increasing speed until the standard maximum rate of 6 amperes is reached at a car speed of 16 or 17 miles per hour. From this speed to 20 or 21 miles per hour it remains practically constant, but above 21 miles per hour it decreases gradually until at the upper speed limit of the engine it may become as low as 3 amperes.
This charging rate conforms throughout with the standard recommendations of the battery manufacturers. The early maximum reached by the starter-generator output provides amply for the demands of current at ordinary driving speeds; while the tapering characteristic, which comes into effect at high speeds, serves to protect the battery from superfluous charging in instances where cars may be subjected to continuous high speed service.
| FIELD COIL | TIE ROD | |||||
| ARMATURE | FIELD RING | FUSE | ||||
| RETAINING PLATE | ||||||
| CORK PACKING WASHER | COMMUTATOR | |||||
| ARMATURE SHAFT | ||||||
| BALL BEARING | ||||||
| SPROCKET | COMMUTATOR-END HOUSING | |||||
| 3RD BRUSH PLATE ADJUSTING-STUD | ||||||
| SPRING END-PLAY WASHER | ||||||
| BALL BEARING LOCKING SLEEVE | ||||||
| BEARING-CAP | ||||||
| FELT OILING-WASHERS | ||||||
| BALL BEARING | ||||||
| OIL SLINGER. | CLAMP-SCREW | |||||
| 3RD BRUSH PLATE CLAMP | ||||||
| CRIMPED SPACER | COVER-BAND | |||||
| SPROCKET-END HOUSING | BRUSH-HOLDER STUD | |||||
| BRUSH | ||||||
| BRUSH HOLDER | ||||||
Fig. 92. North East Model G Starter-Generator
Adjustment of Charging Rate.—The third brush system is so constructed as to permit the charging rate to be changed when desired to a higher or to a lower value than that for which it is normally adjusted. Such adjustments should not be attempted by the car owner himself, and should never be made except in cases of actual necessity where the normal charging rate does not meet the special service conditions under which the equipment may be required to operate permanently. In every instance where there is any reason to believe that a modification of the rate would be beneficial, the car owner should refer the equipment to the North East Electric Company or its nearest branch or service station.
Fuse.—The fuse is located on the commutator end of the starter-generator. Its purpose is to protect the electrical system if possible by rendering the starter-generator inoperative whenever abnormal operating conditions may occur. Due to its protective function the fuse is always the first point in the system to be inspected in case the starter-generator ever failed to produce current. If the fuse is found to be “blown” or missing, a new one should be applied and the machine given a preliminary test before further search for trouble is made. Should the generator fail to deliver current even after a new fuse has been installed or should the new fuse “blow” when the machine is in operation, the entire electrical system should then be inspected thoroughly for possible faults such as open circuits, improper connections or abnormal grounds. Under such circumstances the difficulty should always be corrected before any further attempt is made to operate the equipment.
Precautions Necessary for the Operation Without Battery in Circuit.—The third brush regulating system requires a closed charging circuit for the successful performance of its duties. The battery, therefore, forms an indispensable link in the system and its presence in circuit is always essential to the proper operation of the starter-generator. Should the machine ever have to be operated with the battery disconnected or with the charging circuit otherwise incomplete, the electrical system must be protected by rendering the machine inoperative. This is to be done by removing the fuse from its clips.
When the starter-generator thus rendered incapable of producing current, no ignition current will be available from the usual sources. Under such circumstances, therefore, the engine cannot be operated without some provisional source of ignition current. A battery of nine or ten dry cells will serve satisfactorily as a temporary substitute provided they are used for ignition only.
Starting Switch and Reverse Current Cut-out.—The reverse current cut-out is located in the same case with the starting switch. This combined switch and cut-out is mounted near the center of the toe-board where the switch push-rod button is within convenient reach from the driver’s seat.
CHAPTER XXV
THE DELCO ELECTRICAL SYSTEM—BUICK CARS
The motor generator which is located on the right side of the engine is the principal part of the Delco System. This consists essentially of a dynamo with two field windings, and two windings on the armature with two commutators and corresponding sets of brushes, in order that the machine may work both as a starting motor, and as a generator for charging the battery and supplying the lights, horn and ignition. The ignition apparatus is incorporated in the forward end of the motor generator. This in no way affects the working of the generator, it being mounted in this manner simply as a convenient and accessible mounting. The motor generator has three distinct functions to perform which are as follows:
1.—Motoring the generator.
2.—Cranking the engine.
3.—Generating electrical energy.
Motoring the generator is accomplished when the ignition button on the switch is pulled out. This allows current to come from the storage battery through the ammeter on the combination switch, causing it to show a discharge. The first reading of the meter will be much more than the reading after the armature is turning freely. The current discharging through the ammeter during this operation is the current required to slowly revolve the armature and what is used for the ignition. The ignition current flows only when the contacts are closed, it being an intermittent current. The maximum ignition current is obtained when the circuit is first closed and the resistance unit on the front end of the coil is cold. The current at this time is approximately 6 amperes, but soon decreases to approximately 31⁄2 amperes. Then as the engine is running it further decreases until at 1000 revolutions of the engine it is approximately 1 ampere.
| LEAD TO SWITCH. | |||
| TO SHUNT FIELD. | IGNITION COIL. | RESISTANCE UNIT. | |
| TO THIRD BRUSH. | |||
| TO POS. BATTERY. | DIS. HEAD LOCATING TONGUE. | ||
| TO NO 1 TERMINAL. | |||
| TO NO 2 TERMINAL. | |||
| BRUSH OPERATING ROD. | OILER A. | ||
| TO STARTING PEDAL. | |||
| STARTING GEARS. | |||
| A | FIELD COIL. | ||
| OILER B. | DISTRIBUTOR SHAFT GEAR. | ||
| FLY WHEEL. | PUMP SHAFT. | ||
| ARMATURE. | |||
| LUBRICATOR C. | |||
| GENERATOR CLUTCH. | |||
| ROLLER BEARING. | BALL BEARING. | ||
| OIL DRAIN. | |||
| ONE WAY CLUTCH BUILT IN THIS GEAR. | MOTOR COMMUTATOR. | GENERATOR COMMUTATOR. | |
Fig. 93. Delco Motor Generator—Showing Parts
This motoring of the generator is necessary in order that the starting gears may be brought into mesh, and should trouble be experienced in meshing these gears, do not try to force them, simply allow the starting pedal to come back giving the gears time to change their relative positions.
A clicking sound will be heard during the motoring of the generator. This is caused by the overrunning of the clutch in the forward end of the generator which is shown in [Fig. 93].
The purpose of the generator clutch is to allow the armature to revolve at a higher speed than the pump shaft during the cranking operation and permitting the pump shaft to drive the armature when the engine is running on its own power. A spiral gear is cut on the outer face of this clutch for driving the distributor. This portion of the clutch is connected by an Oldham coupling to the pump shaft. Therefore its relation to the pump shaft is always the same and does not throw the ignition out of time during the cranking operation.
The cranking operation takes place when the starting pedal is fully depressed. This causes the top motor brush to come in contact with the motor commutator. As this brush arm lowers, it comes in contact with the gear in the generator brush arm raising the generator brush from its commutator. At the same time the current from the storage battery flows through the heavy series field winding, motor brushes and motor winding on the armature. The switching in this circuit is accomplished by means of the top motor brush which is operated from the starting pedal. (Shown in [Fig. 94]).
This cranking operation requires a heavy current from the storage battery, and if the lights are on during the cranking operation, the heavy discharge from the battery causes the voltage of the battery to decrease enough to cause the lights to grow dim. This is noticed especially when the battery is nearly discharged; it also will be more apparent with a stiff motor or with a loose or poor connection in the battery circuit. It is on account of this heavy discharge current that the cranking should not be continued any longer than is necessary, although a fully charged battery will crank the engine for several minutes.
Brush Operating Rod
Motor Brush
Generator Brush
Generator
Commutator
Motor Commutator
Third Brush
Plate Slotted To Permit
Third Brush Adjustment
Fig. 94. Delco Motor Generator—Diagram of Operation
During the cranking operation the ammeter will show a discharge. This is the current that is used both in the shunt field winding and the ignition current; the ignition current, being an intermittent current of comparatively low frequency, will cause the ammeter to vibrate during the cranking operation. If the lights are on the meter will show a heavier discharge.
The main cranking current is not conducted through the ammeter, as this is a very heavy current and it would be impossible to conduct this heavy current through the ammeter and still have an ammeter that is sensitive enough to indicate accurately the charging current and the current for lights and ignition.
As soon as the engine fires the starting pedal should be released immediately, as the overrunning motor clutch is operating from the time the engine fires until the starting gears are out of mesh. Since they operate at a very high speed, if they are held in mesh for any length of time, there is enough friction in this clutch to cause it to heat and burn out the lubricant. There is no necessity for holding the gears in mesh.
The motor clutch operates between the flywheel and the armature pinion for the purpose of getting a suitable gear reduction between the motor generator and the flywheel. It also prevents the armature from being driven at an excessively high speed during the short time the gears are meshed after the engine is running on its own power.
This clutch is lubricated by the grease cup A, shown in [Fig. 93]. This forces grease through the hollow shaft to the inside of the clutch. This cup should be given a turn or two every week.
When the cranking operation is finished the top brush is raised off the commutator when the starting pedal is released. This throws the starting motor out of action ([Fig. 94]). The top brush comes in contact with the generator commutator, and the armature is driven by the extension of the pump shaft.
At speeds above approximately 7 miles per hour the generator voltage is higher than the voltage of the storage battery which causes current to flow from the generator winding through the ammeter in the charge direction to the storage battery. As the speed increases up to approximately 20 miles per hour this charging current increases, but at the higher speeds the charging current decreases.
Lubrication.—There are five places to lubricate the Delco System:
1. The grease clutch for lubricating the motor clutch.
2. Hole at B ([Fig. 93]) for supplying cup grease for lubricating the generator clutch and forward armature bearing.
3. The oiler C in the rear end cover for lubricating the bearing on the armature shaft. This should receive a few drops of oil once a week.
4. The oil hole in the distributor at A ([Fig. 93]) for lubricating the top bearing of the distributor shaft. This should receive oil once a week
5. This is the inside of the distributor head. This should be lubricated with a small amount of vaseline, carefully applied two or three times during the first 2000 miles running of the car, after which it will require no attention. This is to secure a burnished track for the rotor brush on the distributor head. This grease should be sparingly applied and the head wiped clean from dust and dirt.
The combination switch ([Figs. 95] and [96]) is for the purpose of controlling the lights, ignition, and the circuit between the generator and the storage battery. The button next to the ammeter controls both the ignition and the circuit between the generator and the storage battery, the latter circuit being shown in the heavier line as shown on the circuit diagram ([Fig. 98]). The button next to this controls the head lights. The next button controls the auxiliary lamps in the head lights. The button on the left controls the cowl and tail lights.
The circuit breaker is mounted on the combination switch as shown in [Fig. 96]. This is a protective device, which takes the place of a fuse block and fuses. It prevents the discharging of the battery or damage to the switch or wiring to the lamps, in the event of any of the wires leading to these becoming grounded. As long as the lamps are using the normal amount of current the circuit breaker is not affected. But in the event of any of the wires becoming grounded an abnormally heavy current is conducted through the circuit breaker, thus producing a strong magnetism which attracts the pole piece and opens the contacts. This cuts off the flow of current which allows the contacts to close again and the operation is repeated, causing the circuit breaker to pass an intermittent current and give forth a vibrating sound.
Fig. 95. Delco Ignition Switch Plate
Circuit Breaker
Numbers of Lower Terminals
Fig. 96. Delco Ignition Switch Circuit Breaker—Mounted
It requires 25 amperes to start the circuit breaker vibrating, but once vibrating a current of three to five amperes will cause it to continue to operate.
In case the circuit breaker vibrates repeatedly, do not attempt to increase the tension of the spring, as the vibration is an indication of a ground in the system. Remove the ground and the vibration will stop.
The ammeter on the right side of the combination switch is to indicate the current that is going to or coming from the storage battery with the exception of the cranking current. When the engine is not running and current is being used for lights, the ammeter shows the amount of current being used and the ammeter hand points to the discharge side, as the current is being discharged from the battery.
When the engine is running above generating speeds and no current is being used for lights or horn, the ammeter will show charge. This is the amount of current that is being charged into the battery. If current is being used for lights, ignition and horn, in excess of the amount that is being generated, the ammeter will show a discharge as the excess current must be discharged from the battery, but at all ordinary speeds the ammeter will read charge.
The ignition coil is mounted on top of the motor generator as shown in [Fig. 94] and is what is generally known as the ignition transformer coil. In addition to being a plain transformer coil it has incorporated in it a condenser (which is necessary for all high tension ignition systems) and has included on the front end an ignition resistance unit.
The coil proper consists of a round core of a number of small iron wires. Wound around this and insulated from it is the primary winding. The circuit and arrangement of the different parts are shown in [Fig. 97]. The primary current is supplied through the combination switch through the primary winding and resistance through the coil, to the distributor contacts. This is very plainly shown in [Fig. 98]. It is the interrupting of this primary current by the timer contacts together with the action of the condenser which causes a rapid demagnetization of the iron core of the coil that induces the high tension current in the secondary winding. This secondary winding consists of several thousand turns of very fine copper wire, the different layers of which are well insulated from each other and from the primary winding. One end of the secondary winding is grounded and the other end terminates at the high tension terminal about midway on top of the coil. It is from this terminal that the high tension current is conducted to the distributor where it is distributed to the proper cylinders by the rotor shown in [Fig. 98].
| Connects To Switch | High Tension Wire To Center Of Distributor | Connects To Distributor |
| Primary Winding | Resistance Unit | |
| Secondary Winding | Iron Core | |
| Condenser | ||
| Coil Bracket Must Be Grounded | ||
Fig. 97. Delco Ignition Coil
The distributor and timer, together with the ignition coil, spark plugs, and wiring, constitute the ignition system.
The proper ignition of an internal combustion engine consists of igniting the mixture in each cylinder at such a time that it will be completely burned at the time the piston reaches dead center on the compression stroke. A definite period of time is required from the time the spark occurs at the spark plug until the mixture is completely expanded. It is therefore apparent, that, as the speed of the engine increases, the time the spark occurs must be advanced with respect to the crank shaft, and it is for this reason that the Delco ignition systems are fitted with an automatic spark control.
| CIRCUIT BREAKER | |||||||
| AMMETER | |||||||
| COWL LIGHT | |||||||
| RESISTANCE UNIT | SWITCH | ||||||
| BRUSH SWITCHES OPERATED BY STARTING PEDAL | CONDENSER | ||||||
| IGNITION COIL | TONNEAU LIGHT | HEAD LIGHTS | |||||
| SERIES FIELD | ROTOR FOR DISTRIBUTING HIGH TENSION CURRENT | ||||||
| MOTOR | GENERATOR | TAIL LIGHT | |||||
| STORAGE BATTERY | SHUNT FIELD | TO SPARK PLUGS DISTRIBUTOR | ADVANCE TUNGSTEN TIMING CONTACTS | AUX LIGHT | |||
| HORN BUTTON IN WHEEL | |||||||
Fig. 98. Delco Wiring Diagram—Buick Cars
The quality of the mixture and the amount of compression are also factors in the time required for the burning to be complete. Thus a rich mixture burns quicker than a lean one. For this reason the engine will stand more advance with a half open throttle than with a wide open throttle, and in order to secure the proper timing of the ignition due to these variations and to retard the spark for starting, idling and carburetor adjusting, the Delco distributor also has a manual control.
Rotor Button
Rotor
Breaker Cam
Timing Adjustment
Automatic Weights
Advance Lever
Fig. 99. Delco Ignition Distributor
The automatic feature of this distributor is shown in [Figs. 99] and [100]. With the spark lever set at the running position on the steering wheel (which is nearly all the way down on the quadrant), the automatic feature gives the proper spark for all speeds excepting a wide open throttle at low speeds, at which time the spark lever should be slightly retarded. When the ignition is too far advanced it causes loss of power and a knocking sound within the engine. With too late a spark there is a loss of power which is usually not noticed except by an experienced driver or one very familiar with the car and heating of the engine and excessive consumption of fuel is the result.
The timer contacts shown at D and C ([Fig. 100]) are two of the most important points of an automobile. Very little attention will keep these in perfect condition. These are tungsten metal, which is extremely hard and requires a very high temperature to melt. Under normal conditions they wear or burn very slightly and will very seldom require attention; but in the event of abnormal voltage, such as would be obtained by running with the battery removed, or with the ignition resistance unit shorted out, or with a defective condenser, these contacts burn very rapidly and in a short time will cause serious ignition trouble. The car should never be operated with the battery removed.
3 AUTOMATIC
WEIGHTS
DISTRIBUTOR
CONTACT BREAKER
CAM
Fig. 100. Delco Ignition Contact Breaker and Timer
It is a very easy matter to check the resistance unit by observing its heating when the ignition button is out and the contacts in the distributor are closed. If it is shorted out it will not heat up, and will cause missing at low speeds.
A defective condenser such as will cause contact trouble will cause serious missing of the ignition. Therefore, any of these troubles are comparatively easy to locate and should be immediately remedied.
These contacts should be so adjusted that when the fiber block B is on top of one of the lobes of the cam, the contacts are opened the thickness of the gauge on the distributor wrench. Adjust contacts by turning contact screw C, and lock nut N. The contacts should be dressed with fine emery cloth so that they meet squarely across the entire face.
The rotor distributes the high tension current from the center of the distributor to the proper cylinder. Care must be taken to see that the distributor head is properly located, otherwise the rotor brush will not be in contact with the terminal at the time the spark occurs.
The distributor head and rotor should be lubricated as described under the heading “[Lubrication].” The amount of ignition current required for different speeds is described under the heading “[Motoring the Generator].”
CHAPTER XXVI
STORAGE BATTERY
Construction, Operation and Care
The modern storage battery does not produce or generate electrical force. It was designed to carry an extra supply of current in storage to operate lighting and starting systems, and in most cases the current required for ignition is drawn from this supply.
Terminal Post
Cell Retainer Case
Cell Jar
Negative Plate
Separator
Positive Plate
Fig. 101. Storage Battery, Sectional View
A storage battery is also called an accumulator, as it accumulates and retains a charge of electrical current for future use.
[Fig. 101] illustrates a storage battery with a section of the cell retainer case removed to show the location of the cells, their respective order, terminal posts and connections. A section of the cell jar, has also been removed to show the core, which consists of a set of positive and negative plates. The positive plates are inserted between the negative plates and are held in this position through their respective connections to the positive and negative terminal posts. The cell retainer-jars are made of zinc or rubber, and contain an acid and water solution called electrolyte into which the core is entirely immersed.
The Positive and Negative Plates.—The plates are held from direct contact with each other by a wood or rubber separator. These plates are formed with small sectional compartments called grids, into which a lead compound in paste form is pressed. The positive plates are made of lead oxide (zinc), and are dark gray in color, while the negative plates are made of pure lead, and are light gray in color.
Cells.—The cells are connected up in series, that is, the positive terminal post of one cell is connected to the negative terminal post of the next cell, forming a direct path through the cell arrangement. Each cell will retain a two-volt pressure until fully discharged. The voltage of a battery is determined by adding the number of two-volt cells that it contains.
Amperage.—The standard type of storage battery shown in [Fig. 102] is composed of three two-volt cells which form a six-volt unit of sixty ampere hours, which means that a fully charged battery will deliver one ampere per hour for sixty hours. This, also, is about the rate of amperage consumed by the modern battery ignition system.
Electrolyte Solution.—The electrolyte solution is composed of a mixture of one part of sulphuric acid added to four to six parts of water. This solution is poured into the cell through the filler cap, until the plates are covered from one-fourth to one-half inch in depth as shown in [Fig. 102].
Care should always be exercised to keep the air vent in the filler cap free from grease and dirt in order that the gases formed through evaporation may escape.
Battery Charging.—The cells are charged by passing a direct current through them, which causes a chemical action to take place as the current flows in, changing the nature of the positive and negative plates, thereby retaining a current force equal to the difference of the changed nature of the plates. The battery is entirely discharged when the plates become alike in nature.
| Unscrew this Cap | |||
| Fill up to this Point | |||
| SOLUTION | Don’t fill above this Point | ||
| PLATE | |||
Fig. 102. Storage Battery, Sectional View
Storage Battery Care and Maintenance.—Regularly once every week during the summer, and every two weeks during the winter, add water to each of the three cells of the battery, until the tops of the plates are covered. Use water only; never add acid of any kind. Water for battery purposes should be distilled fresh rain or melted ice, and must be free from alkali, iron, or other impurities. The battery should be kept clean and free from dirt. Use only clean non-metallic vessels for handling and storing water for battery purposes.
The state of charge of a battery is indicated by the specific gravity or density of the solution. [Fig. 103] shows a hydrometer syringe used for taking specific gravity readings. The filler or vent plug in the top of the cell is removed and the rubber tube of the hydrometer syringe inserted into the cell so that the end of the tube is below the solution. Then squeeze the rubber bulb slowly, drawing the solution into the acid chamber until the hydrometer floats.
Fig. 103. Hydrometer Syringe
The reading on the graduator stem at the point where it emerges from the solution is the specific gravity or density of the solution.
[Fig. 103] shows an enlarged section of the hydrometer floating so that the reading of the graduated scale is 1.280 at the point where it emerges from the solution. This is the specific gravity or density of the solution.
After testing, the solution must be returned to the cell from which it was taken.
Never take specific gravity readings immediately after adding water to the cells.
The specific gravity readings are expressed in “points,” thus the difference between 1.275 and 1.300 is 25 points.
When all the cells are in good condition the specific gravity will be approximately the same in all cells and the difference should not be greater than 25 to 30 points.
With a fully charged battery the specific gravity of the solution will be from 1.280 to 1.300.
Specific gravity readings above 1.200 indicates that the battery is more than half charged.
Specific gravity readings below 1.200, but above 1.150 indicates battery less than half charged.
Gravity below 1.150 indicates battery discharged or run down.
Should the gravity fall below 1.150 the gas motor should be given a long run with all lights turned off, to restore the battery.
This condition may result from leaving a car standing for prolonged periods with all lights in use and insufficient running of the gas motor in between these periods to replace the current taken to supply the lights.
When the specific gravity shows the battery to be half discharged, the lights should be used sparingly until the gravity rises to approximately 1.275.
If the specific gravity in one cell is much lower than that of the others, and if successive readings show the difference to be increasing, this indicates that the cell is not in good order.
If one cell regularly requires more water than the others (continually lowering the specific gravity), a leaky jar is indicated. Leaky jars should be replaced immediately.
If there is no leak and the specific gravity falls 50 to 75 points below that of the other cells in the battery, an internal short circuit is indicated and should be remedied.
Battery to Remain Idle.—Where a battery is to remain out of active service for a long period, it may be kept in good condition by giving it a freshening charge at least once a month, by running the gas motor idle.
When a battery has been out of service for some time it should be given a thorough charge before it is placed in service again.
If the gas motor cannot be run to give a freshening charge, the battery should be taken from the car and placed at a garage, which makes a business of charging storage batteries. It can be charged at least once a month. This charge should be 4 and 3⁄4 to 5 amperes for twenty-four hours.
Battery Freezing.—In order to avoid freezing, a battery should be kept in a fully charged condition, as a fully charged battery will not freeze except at extreme temperatures. As a battery discharges the specific gravity of the solution decreases, and the specific gravity of a fully discharged battery will be approximately 1.120. Batteries of this low gravity will freeze at 20° F. above zero, whereas, the density of the solution in a battery approximately three-quarters charged will be 1.260, and a solution of this density will not freeze until 60° F. below zero.
See [Accumulator]. Chapter 14, Electrical Dictionary—Function and Chemical Action.
CHAPTER XXVII
SPARK PLUGS AND CARE
Some definite knowledge of spark plug construction quality, and care, will be found very useful to the average motorist in purchasing new plugs, and keeping those in present use, in good condition. A good plug properly constructed should outlast the life of the motor. When purchasing new plugs, first examine the old plug and get one of the same length. This is very important as spark plugs are made in as many different lengths as required by high and low compression motors. High compression motors have a small low walled combustion chamber, while low compression motors usually have a spacious high wall chamber and require a longer plug, whereas if the long plug is used in the high compression motor it may be put out of commission by the ascending piston. Next determine the size of the plug and the gauge of the thread. The majority of motors use the 3⁄4 inch plug, with the S. A. E. thread, while a few still use the A. L. A. M. thread which is much finer gauged. Another point to be remembered is that it is an unwise expenditure to purchase cheap plugs because the intense heat and pressure that they are subjected to and required to stand, demands that they be made of the highest quality of material and workmanship.
Fig. 104. Spark Plug
[Fig. 104] shows the sectional construction of a spark plug costing from one dollar to one dollar and fifty cents. No. 1, the terminal, is designed to fit all connections. No. 2 nut which holds electroids firmly in place. No. 3 represents round edged shoulders which prevent the plug from short circuiting on the outside. No. 4 is a heavy electroid which will not break or burn. No. 5 is an extra heavy insulator which insures a good spark in case the outer porcelain insulator becomes broken or cracked. No. 6 is a bushing which holds the insulator firmly in place from the top. No. 7 is a high compression washer which allows for upward expansion and makes an even seat for the bushing which holds the insulator in position. No. 8 is a massive porcelain insulator designed to withstand a high temperature without cracking. No. 9 is a copper asbestos washer that allows for the downward expansion of the insulator. No. 10 is the shell casting which holds and protects the insulator. No. 11 are rounded corners which will allow the plug to be screwed down flush without coming into contact with the curved walls of the cup containers. No. 12 is a high compression washer which prevents all leakage. No. 13 shows elastic cement which strengthens the lower construction of the insulator and prevents the compression from escaping through the center of the insulator. No. 14 is a hardened polished steel tipped electroid. No. 15 is a bent polished steel electroid dipped on each side of the spark in order to prevent oil from running down from the shell casting and closing the spark gap. No. 16 represents an extended center electroid which prevents any oil that may have lodged on it from stopping at the spark gap.
Spark Plug Cleaning.—To insure a smooth running motor and a good spark, the spark plugs should be cleaned at thirty day intervals. It is not always necessary to disassemble them at this time as the carbon usually collects and bakes on the metal casting shell and can be removed by running a thin knife blade or finger nail file around the inner surface. However, when the insulator becomes pitted or carbon burnt the plug should be disassembled and the insulator wiped clean with a cloth dampened in kerosene. Never immerse the insulator in kerosene, as this will loosen the cement around the center electroid and cause the plug to leak compression. The shell may be immersed. It is then wiped dry and the inside surfaces scraped or rubbed with a piece of sand or emery paper to dislodge the carbon pits. After all parts have been thoroughly dried the plug is reassembled, using new washers.
CHAPTER XXVIII
CLUTCH CONSTRUCTION, TYPE AND CARE
The clutch used in automobile construction of the present day becomes a necessary part of the equipment upon the adoption by manufacturers of the progressive and selective types of sliding gear transmissions.
When the engine is started the clutch is “in,” that is, in contact with the flywheel, and all parts of the clutch revolve with it at the same speed. The shaft on which the clutch is mounted extends into the transmission gear case, but as the transmission gears are in a neutral position, the movement of the car is not affected.
When the car is to be started the clutch foot pedal (usually on the left side of the steering column) is pressed down. This throws the part attached to the drive shaft out of contact with the part attached to the flywheel, and in its backward movement it comes into contact with the clutch brake, as shown in [Fig. 105], which stops it from revolving. The hand gear control lever is shifted into the first speed slot or position. The pressure on the foot pedal is then gradually released and the clutch is carried in by spring tension, and the car moves off at first speed.
Second Speed.—The clutch is thrown “out” after a brief lapse of three to five seconds has been allowed for the brake to slow up rotation in order that the gears to be meshed will be rotating at the same speed. The hand control lever is now shifted into the second speed slot, and the clutch pedals released.
High Speed or Direct Drive.—The clutch is thrown out and a few seconds allowed for it to slow up. The hand control lever is shifted into the high speed slot, which connects the drive or propeller shaft directly to the clutch shaft and the car is driven at crank shaft speed when the clutch is let in.
Reverse.—The clutch is employed in the same manner. However, the motion of the car, the clutch and all gears must be at a stand still before the gear control lever is shifted to the reverse speed slot, as the gears in the transmission operate in the opposite direction.
Fig. 105. Cone Clutch and Brake