A loader device for a hopper-fed processing machine has a top plate pivotally secured to a bottom plate. The plates are attached between the processing equipment throat and the material hopper, or vacuum receiver/reservoir. As the top plate pivots upon the other, ports that extend through the plates control the flow of material from the hopper into the throat of the machine. The pivot design, a purge funnel, and a drain tube are additional features that save time, labor, and make switching of processing material quick and convenient without the use of tools.