The WPT type, vibration, trapezoidal feeders are destined for feeding materia! with grain size up to 250 mm to screens 2.2; 2.6 and 3.0m wicie, which require more even feed of materia! for crushing on the entire width of the screen surface. The feeder chute on a springy support makes free vibrating movements with linear trajectories caused by an inertial drive. The drive comprises two shafts with unbalanced masses, with bearings ina closed box, synchronized by a pair of gears. One of the shafts is connected directly through a flexible coupling with a drive motor. The stroke and inclination angle of the chute can be adjusted depending on the requested output.