A device for entering dyes having a consistency, which may vary from a liquid to a pulverous state, into synthetic material processing machines, especially extrusion and injection molding machines, by means of a hose pump adjustable as to the quantity being delivered thereby. The device includes a rotor...http://www.google.ca/patents/US4132509?utm_source=gb-gplus-sharePatent US4132509 - Peristaltic pump with means to vary relative pumping volume between tubes
