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Fig. 164.—Sectional View of Typical 1914 Starting Motor Showing Reduction Gearing, Overrunning Clutch
and Sliding Gear to Engage Teeth on Engine Flywheel.
Switches and Current Controlling Devices
L. The roller travels with the clutch and runs free against the side of the gear B when the engine is in motion and when the starting gears are idle. As soon as the current is directed to the electric starting motor, the three rollers are bound between the clutch body and the ratchet member carrying them and the crankshaft is driven until such time as the engine speed increases sufficiently to overrun that of the member attached to the crankshaft.
Overrunning clutches are not always used in those systems in which the gears are moved into engagement, as in that shown at Fig. 163, the clutch is omitted. It is used in the design shown at Fig. 164 however. In this former, the starting switch and the double shifting member, GH, are mechanically interconnected so that the starting switch will not be completely engaged until gearing is in mesh. The larger gear H of the sliding members meshes with that on the armature shaft, while the smaller of the pair, G, meshes with the flywheel. The arrangement of the parts outlined is used on the Cole car. In the Hartford starting motor, which is shown at Fig. 152, A, the clutch is of the friction type and is engaged automatically when the energy is passed through the motor winding to produce movement of the engine crankshaft. The reduction between the starting motor and the crankshaft is made by a worm and worm gear. When the switch pedal is depressed and the switch blades go into contact the same movement produces pressure on the end of the lever attached to R R, which transmits a strong pull on the friction clutch and thus connects the motor to the starting gear. The Ward Leonard combination is shown at Fig. 152, B. In this the motor is carried above the generator, and but one driving gear is needed to operate both the generator and to enable the starting motor to turn over the engine crankshaft. The speed reduction is by an intermediate gear shaft, the general operation being the same as that of the starter previously described.
Switches and Current Controlling Devices. The various methods of operating the starting switch, which may be interconnected with the gearing to turn the crankshaft, are shown at Fig. 165. All of the methods of actuating the electric self-starter may be grouped into three main classes: one, by hand lever; two, by pedals, and three, by semi-automatic means. The method at A is used on some Paige-Detroit cars, a hand lever, A, attached to the steering column being used to make the mechanical interconnection between the clutch pedal and the starting gear mechanism. In order to safeguard the gearing of the starter the electrical connection
Fig. 165.—Methods of Actuating Motor Starting Mechanism.
cannot be effected until this mechanical interconnection is made. After the hand lever is thrown over in the proper position, depressing the clutch pedal suffices to permit the electrical connection to be made and the gasoline engine started. In the Hupmobile control, which is shown at B, a small auxiliary lever S is used to put the starter into gear. The view at D shows a small pedal which is employed to make the starting connection. This is the most popular system, especially when the pedal is connected with the current-controlling switch, so that the full amount of current will not flow to the motor until the reduction gearing is completely engaged.
An example of the semi-automatic method which is used on the cars employing the Entz starter, namely, the Franklin, Chalmers
Fig. 166.—Construction of Typical Starting Switches.
and White, is shown at C. To put the starter in operation it is only necessary to move the handle H on the dashboard or other convenient position, where it may be readily reached with the hand or foot. This method is called the semi-automatic, because the starter operates all the time until the gasoline engine is stopped by short circuiting the ignition. The first step is to throw the han
dle to the ignition point, and after closing the ignition switch, it is moved in the same direction until the storage battery has been connected to the starter generator. It is not necessary to touch the handle again until one desires to stop the engine, as moving the handle to the other extreme of its operating quadrant first opens the connection between the storage battery and the motor generator and then interrupts the ignition. With this starting system, if the
Fig. 167.—Side View of King Eight Cylinder Power Plant Showing
Location of Current Generator and Ignition Distributor.
motor should be stalled for any reason or slow down below its normal cranking speed the starting motor-generator unit automatically changes from a generator to a motor and turns the gasoline engine crankshaft, making it practically impossible to stall the engine with this type of starter.
Owing to the large amount of current starting switches must carry, they are made much heavier in construction than lighting switches. They must be mechanically strong and the contact areas