Styrofoam Bean manual measure & fill

We require a measuring/dispensing apparatus which will fill a measuring container with approximately 6 litres of styrofoam beans. When the measuring hopper is filled a lever action closes the fill input and the output is activated with gravity feed through a 90mm pipe to the receptacle (a furnishing item). Consistent volume is required for each fill cycle and there should be some mechanism to adjust and lock the fill volume of the measuring receptacle. The source of beans will generally be a large hopper mounted above the mechanism with a pipe or tube to the filling input. The operator works on this unit, seated, with the control lever at around desk height. There should be interlocks preventing both outlet and input being open simultaneously. The apparatus should be compact and lightweight (some devices will be despatched overseas) and easy to mount in a frame. Only the filling/measuring apparatus is required to be constructed. It should have no sharp edges or dangerous parts. There should be two or more outlets to fill two items at a time, or sequentially (sequential preferred as one measuring container can be filled from above while the other empties into product hence saving time) It should be able to perform at least four fill cycles per minute. The device should be easy and fast to make additional units as we may order several.