THE CLEANING APPARATUS. 145 



or seed. This adjustment may be made while the machine 

 is running. All Case separators are now regularly fitted with 

 an adjustable conveyor-sieve, commonly called the "chaffer," 

 adjustable conveyor-extension and adjustable shoe-sieve. 

 The latter should be placed in the shoe with the rear rod in 

 the fourth hole and the front end high enough to leave only 

 an inch between it and the heel board of the shoe. 



The Conveyor-Extension or Chaffer-Extension carries the 

 coarse chaff from the conveyor sieve to the stacker. The con- 

 veyor sieve should be so adjusted as to let all the good grain 

 through because that which goes to the extension and drops 

 through it is returned with the tailings to the cylinder. The 

 conveyor-extension should be coarser than the conveyor sieve 

 so as to allow all the unthreshed heads to pass through. If 

 they pass over it they are lost. The present style of adjust- 

 able conveyor extension is hinged to the rear of the con- 

 veyor sieve and also fastened to the conveyor side-rails. By 

 loosening the bolts which hold it to the side rails this exten- 

 sion may be lifted out of the way to get at shoe sieves. 



Common Sieves is the name given to non-adjustable 

 sieves and includes the lip, the round-hole, the oblong-hole 

 and the woven-wire sieves. 



Fig. 41 shows the nine positions or notches, in which a 

 sieve may be placed at the fan end of the shoe, and they 

 are numbered, beginning at the top. It also shows the six 

 positions for the rod at the rear end and these are also num- 

 bered from the top. 



