system the generator is used to charge the storage battery, the current going through the usual automatic cutout switch to prevent a reversal of current at such times that the generator is not supplying enough energy to charge the battery. As is true of the diagram presented above, all of the circuits are clearly shown and may be readily followed by any one.

The construction of the various forms of electric lamps used in motor car lighting systems is clearly shown in Fig. 313. The lamp outlined at A is a combination form, designed to use either kerosene or electricity, the former being used only in the event of failure of the latter. The side lamp at B is a neat form, intended to use electricity only. Dash, coil and speedometer lamps are depicted at C. A combination trouble lamp and cigar lighter is shown at D. The trouble lamp at E is an easily portable form and is convenient for use around the power plant, gasoline tank, etc., deriving its current from the regular battery. A combination tail lamp, having red lens at the rear and a white glass at the side to illuminate the number plate, is shown at F. The approved construction of a variable focus electric head lamp is shown at G.

CHAPTER VII

CLUTCH AND GEARBOX FAULTS

Principal Clutch Troubles Outlined-Cone Clutch Construction and Adjustment-Cone Clutch Repair-Plate and Disc Clutches-Band ClutchesPlanetary Gearset Repair-Friction Drive Faults and RemediesTroubles in Sliding Gear Transmission.

IT is not difficult to locate defects in the power plant, as the symptoms resulting from faulty action of the engine mechanism. and the parts of the auxiliary groups are such that can be readily recognized by comparatively inexperienced repairmen. There are a number of points in the power transmission system that may depreciate in service and their faulty action will not be immediately discovered. There may be serious wear in the power transmission elements, such as the gear box and the rear axle, which will mean a serious diminution in the amount of power delivered to the rear wheels. As these faults are usually of a purely mechanical nature, they are not generally known, and as a rule only show up in a positive manner when a car is overhauled thoroughly.

Principal Clutch Troubles Outlined. The first member of the power transmission system to be considered is the friction clutch in its various forms, and it is important that clutch troubles be readily recognized, as the power, capacity and speed of the entire vehicle will be affected if the clutch action is not as it should be. Considering first the general troubles which are apt to materialize with all types of clutches, we will consider as the most important a too sudden or harsh engagement, which causes "grabbing," failure to transmit the entire engine power, lack of capacity due to failure to engage properly and poor or slow release, which results in "spinning." Clutches that employ frictional material as a facing will not act properly if the material becomes worn or if it

is glazed over. Besides the trouble due to defective friction mem bers, there are other portions of the clutch mechanism that demand care and inspection. As the cone clutch is the most common, we will describe the construction of a typical clutch of this nature and then consider the methods of repairing defects that may materialize in service.

Cone Clutch Construction and Adjustment.-The cone clutch assembly shown at Fig. 314 is that used on National automobiles and is one that has given excellent service. The female member is machined in the flywheel rim while the male member, from which the clutch type takes its name, is a truncated cone or saucer-shaped

Fig. 314.-Clutch and Control Pedal Assembly of National Automobile.

member cast of aluminum, which has a friction facing of leather. The clutch cone transmits power by virtue of frictional adhesion with the flywheel rim, this amount of friction being increased by the wedging action due to the angular face of the clutch members. The pressure maintaining the parts in engagement is produced by

a substantial coil spring carried by the flywheel extension, this spring exerting its pressure against the cone-carrying member and having its reaction absorbed by an anti-friction bearing of the ball form. The power from the clutch cone carrier is transmitted by a double universal joint to the gearbox, placed back of the clutch and about midway on the chassis frame.