TRACTION ENGINES 



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there has to be connected into the transmission gear a 

 reversing gear. The simplest of the reversing gears for 

 gasoline engines now on the market is a system of fric- 

 tion pulleys, such that when the engine is in one posi- 

 tion on the frame the traction wheels will move for- 

 ward. When it is in another position another set of 

 wheels is connected in and the traction wheels will move 

 backward. It will be noticed from this that the engine, 

 which generally weighs 2,000 or 3,000 pounds, has to be 

 slid backward or forward on the mounting frame. 

 Fig. 337 shows a type of engine which reverses as above 



337X3ASOLINE TRACTION ENGINE WITH FRICTION GEARING 



described. This engine is operated by means of a set 

 of friction wheels, instead of a set of gearing as steam 

 traction engines are run. Fig. 338 illustrates an engine 

 which utilizes pinions for its transmission gearing similar 

 to a steam traction engine. 



Rating. Gasoline traction engines are all rated upon 



