-3- 
slightly diagonal direction. A galvanized-iron disk {D) about 10 inches 
in diameter is fastened to each end of the cylinder to hold the belt in 
position against the cylinder. Flanged set collars attach the cylinder 
to a 1/2-inch shaft mounted at each end in self-aligning bronze bushed 
pillow blocks. Set collars to maintain the position of the cylinder and 
a hand crank mounted on the end of the shaft complete the assembly. 
The belt B^ is made from a piece of sponge-rubber rug anchor, about 
1/16 by 7 1/2 by 24 inches, cemented to fly screening of the same dimen- 
sions. A piece of 16- by 16-mesh aluminum fly screen without a cover- 
ing is fairly satisfactory but less so than the rubber-surfaced belt be- 
cause it sometimes becomes clogged with stems. 
The belt girds approximately half of the cylinder like a power belt 
around a pulley, but it does not move with the cylinder. It is held in 
place at each end by clamps (E^ and F^) made of wood or wood and strap 
steel. The end of the belt at _E is held stationary, and the other end is 
attached to the frame by a coil spring (G) at each side. This arrangement 
gives flexibility to the belt when clover heads are poured in for threshing 
through the chute (H), which is made of sheet metal. 
When the machine is viewed as in figures 1 and 2, the cylinder is 
turned counterclockwise to roll and rub clover heads against the belt. 
Since each floret must be ruptured to release the seed, the chaff is 
almost completely pulverized, some of it being carried completely 
around by the revolving cylinder. As the partially pulverized chaff 
containing the seed is taken from the thresher, it is passed through a 
12- by 12-inesh screen and the screenings are returned to the thresher. 
When all florets are ruptured, the material is passed through the 
separator (figs. 3 and 4) to remove the chaff. 
The sides and floor of the thresher are lined with sheet metal, and 
baffles are used on the ends to prevent seeds from being thrown out and 
lost. As a further precaution, the thresher is set in a tray, about 28 
by 60 inches with sides 3 inches high, which catches seeds that may be 
spilled. The belt is detached when the machine is emptied, and all 
seeds can be removed before another lot is processed. 
Seed Separator 
The seed separator, or cleaner, shown in figures 3 and 4, employs 
the air stream of an exhaust fan ins.tead of the usual blower-fan air blast 
to separate seed and remove chaff. An old household fan-type vacuum 
cleaner is used, arranged so that the air stream may be adjusted. All 
separation fractions removed from the seed may be caught by a screen 
and examined. The dusty chaff may be caught in the cleaner bag instead 
of being blown about the laboratory. 
Wooden parts are made of 3/4-inch poplar. Both ends are held in 
place with small metal buttons so they can be removed easily for 
cleaning the main box. 
