Abstract: An apparatus is disclosed for harvesting seed which includes a frame and a housing defining a seed box and having a rotary brush mounted on a forward portion thereof which is connected to link bars which are in turn connected to the frame. Corresponding pairs of link bars are attached between the frame and housing on opposite sides of the apparatus, the link bars on each side being substantially parallel to each other. Means are provided for varying the angle of the link bars to the frame, the link bars operationally functioning as a parallelogram to raise or lower the housing at a constant angle relative to the frame. A draw bar is pivotably connected to the front of the frame and tilt angle adjustment means are provided to vary the angle between the frame and the draw bar thereby providing an independent means for varying the angle of attack of the rotary brush to the plants from which seed is being collected.