126 



FARM MACHINERY 



made to throw a clutch which put the dropper shaft in 

 connection with a chain drive from the main axle. This 

 clutch remained in gear for one revolution of the shaft, 

 which is equivalent to one-fourth revolution of the seed 

 plate. The one-fourth of the seed plate was arranged 

 with enough seed cells to count out one hill. This clutch 

 may be made to operate a valve which will permit a suffi- 



i 

 For Hill Drop 



Fixed to Drill 



FIG. 93 A TRIPLE VALVE MECHANISM SHOWING HOW THE CORN IS RE- 

 LEASED AT THE HEEL OF THE FURROW OPENER 



cient number of kernels to leave the plate to make a hill 

 as described above. The clutch has relieved the check 

 wire of a large portion of its work. It is only required 

 to put the clutch in gear and to open the valves in the 

 shank. The clutch is one of the vital parts of the planter, 

 and is often the first part to wear out and give trouble. 

 Fig. 92 illustrates a planter clutch. 



172. Valves are divided into three classes : single, double 

 and triple valves. The single valve is placed in the heel of 



