94 FARM MACHINERY 



in and out upon the front arch. The spacing in two- 

 row machines should be accomplished by a lever which 

 permits the change to be made while in operation. 



Suspension. The gangs should be so suspended as to 

 swing freely in a horizontal plane. If the point of sus- 

 pension is too far back and the suspending arm or chain 

 too short, the shovels will be lifted out of the ground as 



FIG. 65 A TONGUELESS FOUR-SHOVEL CULTIVATOR WITH WOODEN GANGS. 

 THE SHOVELS ARE NOT IN PLACE 



the gang is carried to either side. The farther ahead the 

 gang is suspended and the longer the suspending arm, 

 the more nearly the gang will swing in a plane. Con- 

 siderable difference is experienced in the ease with which 

 a long gang is guided compared with a short gang. This 

 is due to the fact that as a short gang is swung to one 

 side more work is done, as the shovels must be carried 

 ahead ; while with a long gang the shovels are not carried 

 ahead to such an extent. 



Coupling. The double hinge joint by which the culti- 

 vator gang is attached to the frame is called the coupling. 

 Due provision should be found in the coupling for taking 

 up wear. It is impossible to guide properly a gang with 

 much lost motion in the coupling. 



