One of the most practicable and easily operated selectors is shown in Fig. 60, which is used on the Jeffery car.
Controlling the Selector.—It will be seen, on examination of the selector, that if, in starting, the lever is at its neutral position, as it should be, and it is moved inwardly the distance of about an inch, it will be in position where it can be moved forward to the first speed position.
The clutch of the car may then be disengaged gently, by pressing the foot down slowly, and at the same time pressing the accelerator with the right foot, so as to increase the speed of the motor sufficiently to take care of the load.
After the clutch engages and the car has traveled about ten feet, pressure on the accelerator is released, and the clutch pedal pulled down quickly, and the lever is then pulled straight back to the second speed.
Using the Clutch and Selector.—For the third and fourth speeds the same course is followed. If, in hill climbing, or in going through a heavy stretch of mud or sand, lower speed is required, the clutch is thrown out, and, if traveling on fourth speed, the control lever is quickly pulled to the rear end of the slot, and then the clutch thrown in.
If it is on third speed, the clutch is disengaged, the control lever pushed forward, at the same time pressing it inwardly so it will pass through the gate, and then pulling it back to the second speed.
Fig. 61. Planetary Transmission.
Planetary Transmission.—Fig. 61 shows the general arrangement of the planetary transmission. The disk A, carries four small planet gears B, B, B, B, the hub C´ of which is attached to the transmission shaft. These four planet wheels mesh with and travel around a central gear C, of the same diameter this gear being attached to the engine shaft D.
E is a loosely-revolving drum, with internal teeth, to mesh with the planet wheels B. The drum E, and the disk or planet wheel carrier A, are provided with braking mechanism so that either may be slowed down or entirely stopped.