Abstract: A seed hopper construction for use in connection with rotary drum seed planter requiring positive pressure for its seed metering operation. The hopper comprises a tapering bottom wall with an opening therein and an internal duct associated with said wall and opening. A deformable tubular diaphragm valve is positioned in the duct and projects from the opening in the bottom wall. A vertical air pressure tube is mounted in the hopper and carries a two-position valve for directing air into the hopper or to the diaphragm valve. The pressure tube also has a bottom air inlet depending from the bottom wall. A centrifugal blower having a positive pressure side outlet communicates with the pressure tube air inlet and the seed drum. The blower has a negative pressure central opening in spaced registry with the diaphragm valve.

Abstract: A hitch element is fixed to the end of the piston rod of a horizontally disposed double-acting hydraulic cylinder. The closed end of the cylinder is swivelly connected to the bight portion of a horizontally disposed rearwardly open A-shaped frame underlying and fixed to the rear part of a truck chassis. An upright downwardly-open omega-shaped frame is rigidly connected at its ends to the ends of the A-shaped frame. A pair of upright double-acting cylinders have their closed ends swivelly connected to opposite upper corners of the upright frame, and have their piston rods connected, by X-connected bearing sleeves, to the piston rod of the horizontally disposed cylinder. A yoke prevents movement of the bearing sleeves away from the end of the horizontal cylinder. The upright cylinders co-operate to vary both vertical and lateral positioning of the hitch element.