ELECTRIC AUTOMOBILES. 



481 



is stopped the controller B is turned into such a position that all elec- 

 trical connections between the battery and the motor C are broken. 

 To start the vehicle the controller B is turned so as to make the neces- 

 sary electrical connections between the battery A and the motor C, and 

 then the electric current passes from the battery through the con- 

 trolling switch to the motor, and thence back to the controller and the 

 battery. The heavy broken lines indicate the path of the current and 

 the arrows show the direction. The velocity of the motor and the 

 speed of the carriage are varied by varying the strength of the current, 

 and this is effected by the movement of the controlling switch B. There 

 are many ways in which the movement of this switch can vary the 

 strength of the current, but an explanation of any one of them would 

 be dry and rather technical; hence it is sufficient to say that whatever 

 the arrangement of the connections of the controller with the other 

 parts of the system, their relation is such that by the movement of the 

 switch handle the speed of the motor is changed from zero to the 

 maximum velocitv. 



Q 



2. Double Reduction. 



Fi<;. 3. Single Ueductk.o 



In the majority of American vehicles the motion of the motor is 

 transmitted to the wheels by means of spur gearing. In some cases a 

 single motor is used, in others two; and in one or two designs that have 

 come to public notice, four motors are employed, one for each wheel of 

 the carriage. Fig. 2 illustrates what is commonly called a double re- 

 duction gear for single motor equipment. The outline A represents 

 the motor, B being the shaft. Upon this shaft is mounted a small pin- 

 ion which meshes into a larger wheel on the intermediate shaft C. 

 This shaft carries a pinion which meshes into the wheel D mounted 

 upon the axle of the vehicle. 



Fig. 3 illustrates a single reduction double motor equipment, the 

 motors being located at A A. In this arrangement the pinion on the 

 end of the motor shaft meshes directly into a large gear secured to the 

 carriage wheel, thus dispensing with the intermediate shaft C of the 

 previous figure. The single reduction gear is the more simple in con- 

 struction, but the motors run at a lower velocity, and on that account 

 must be larger for the same capacity. With the double motor con- 



VOL. LVII —31 



