Today in 1951, US Patent 2570844 A was issued, an invention of Axel Oslund, for his “Hop-Picking Machine.” There’s no Abstract, although in the description it includes this summary:

This invention relates to hop picking machines.

It is an object of the present invention to provide a hop picking machine for picking hops from hop vines wherein the vines will be extended through the machine in a vertical direction by a traveling conveyor which is connected to the vine stems and through picking drums acting upon opposite sides of the vine as the vine is pulled upwardly and wherein the drums are arranged in pairs working upon opposite sides of the vine and wherein these drums may be staggered with respect to each other throughout the height of the machine.

It is another object of the present invention to provide a vertical hop picking machine wherein the drums are arranged in pairs and wherein the individual drums from the lower position to the top position are brought closer together for each pair so that the last pair of the drums will be so close that they almost touch one another.

Other objects of the present invention are to provide a hop vine picking machine which is of simple construction, inexpensive tov manufacture and efficient in operation.