Page:Popular Science Monthly Volume 57.djvu/610

600 by a separate chain. In Fig. 6 the sprocket wheel and chain are well defined, and forward of these can be seen the outline of the casing enclosing the gearing.

Fig. 8 shows another European design, in which a variable-speed



gear is used. The plan of the truck, showing the general arrangement of the mechanism, is presented in Fig. 9, and the details of the variable speed gear are shown in Fig. 10. The motor is located at A, and through a friction clutch B, and the variable speed gear C, it rotates the shaft H, which runs lengthwise of the vehicle. Motion is imparted to the hind axle by means of bevel gears contained within the casing D. The large

bevel gear on the axle is of the differential type, so as to drive the wheels R R at the proper velocities.

When a high speed is desired, the variable speed gear, Fig. 10, is set so that shaft M drives N direct, the clutch at E being moved so as to interlock. N is the end of shaft H, so that with this connection the bevel pinion, which meshes into the axle gear at D, revolves at the same velocity as the motor shaft. By moving the handle V, Fig. 9, to the