of fiber which does pass through gap g and falls into the receptacle r is highly opened and thus already suitable for the downstream process this concurrent dual use of the same feeder f with just one charging is not practical with prior art systems because of the wide 34 worse case 34 gap setting required between their impaler and stripper elements consequently when they are first charged with fresh stock much of it escapes the stripping action and the receptacle is very quickly filled this requires that the impaler element be stopped until some of this stock has been removed to overcome this drawback the prior art usually performs the 34 pre opening 34 at a first point and the 34 normal run opening 34 at yet a second point this is often accomplished by the use of two tandem feeders operating in series a 34 breaker 34 feeder feeds a 34 finisher 34 feeder with the present invention it is possible to do with just one hopper feeder what the prior art usually needs two to accomplish it will be noted that the opening zone gap g can be controlled to yield substantially the same results by fixing the stripper s and moving the impaler i relative to it although a driven apron has been disclosed as the preferred form of advancer element a those skilled in the art know that an inclined slide plate whereby gravity slides the mass of fiber b downward and forward into the pins of the impaler i has been successfully used to perform this same function finally it will be noted that various mechanisms are available as equivalent substitutes for the linear actuator m schematically disclosed herein for example fluid operated pistons fitted with.