262 



AGRICULTURAL ENGINEERING 



the cutter bar to the surface of the ground. A draft rod 

 direct from the doubletrees to the cutter bar assists in lower- 

 ing the draft, and is universally used on modern mowers. 

 Adjustments of the Mower. The adjustments of the 

 mower are of the greatest importance. First, the cutter bar 

 should be in alignment, or should extend out to the side of 

 the mower at right angles to the crank shaft. If not in per- 

 fect alignment, the pitman will be cramped, increasing the 

 wear, if not causing early breakage. There is sure to be 

 more or less wear in the hinge joints of the cutter bar, and 



Fig. 164. An illustration showing- the proper adjustment of the 



cutter bar. 



an adjustment must be made for this wear from time to time. 

 The device for aligning the cutter bar differs in each type of 

 mower, yet it is to be found in all good mowers. 



Secondly, the knife should be made to register, or to travel 

 equally over the guards at the ends of the stroke. Misadjust- 

 ment in this respect is often the cause of failure to cut proper- 

 ly. The method of adjustment varies with different mowers. 

 In some the length of the pitman is changed; in others, the 

 length of the drag bar. It is also true that many mowers 

 do not offer a ready means of adjustment. 



