Today in 1920, US Patent 1348139 A was issued, an invention of Horst Emil Clemens, for his “Stem Picker.” There’s no Abstract, although in the description it includes these claims:

This invention relates to a stem picker and especially to a machine for separating stems from hops and the like.

Picking of hops by machinery is resorted to at the present time in several of the larger hop; growing districts and is becoming more and more a necessity due to the scarcity of labor and troubles connected therewith. Hops picked in this manner contain a considerable quantity of leaves and stems and other foreign matter, the major portion of which are removed by separators of various types. It happens however that while the leaves are comparatively easily removed that there still remains a considerable quantity of stems and it is the purpose of the present invention to provide a machine which is particularly adapted for removing the stems. The invention briefly stated involves a longitudinally extending inclined draper belt from the surface of which projects the hops, from which it is series of pins are delivered desired to remove the stems, to one end of this draper belt and will, during the travel of said belt, tend to roll off the belt and to a conveyer which removes them from the stem picking machine, stems` and other similar material being hung up on the pins and later removed as will hereinafter be described.

The invention also involves a mechanism for maintaining the draper in a state of continuous vibration thereby insuring a perfect removal of the hops deposited thereon While in no way impairing the action of the stem separating mechanism.