PERISTALTIC APPARATUS WITH CONTINUOUSLY ADJUSTABLE MEDICATION FEEDING SYSTEM Russian patent published in 1998 - IPC

FIELD: medical equipment, in particular, dosed parenteral injection of liquid medication. SUBSTANCE: peristaltic drive has five pressure pins with punches at their working ends. Punch section in plane extending in parallel with longitudinal axis of pipe is made in the form of semicircle with radius making 1.5-2.0 of pipe outer diameter. Punch spacing is 2.5-3.0 of pipe outer diameter. First three pins downstream of liquid flow are forcing. Fourth and fifth pins serve both to force and damp pulsed liquid flow feeding speed, which is due to the fact that fourth and fifth pins move only half the full working stroke. Fourth pin may cover pipe section to the extent ranging between half and full pipe working section and fifth pin may cover pipe section to the extent ranging between 0.55-0.7 of pipe inner diameter and half the working section. Stems are reciprocated by cams which are divided into four sectors, each of 90 deg. Two main opposite sectors of each cam have radii whose difference is equal to required pin stroke. Two other sectors are made in the form of Archimedes' spiral. Cams on shaft are turned one with respect to another for an angle of 90 deg. Maximum radius of first four cams is selected to provide minimum moment on working shaft during the initial full pinching of pipe, i.e. it requires minimum cam radius. Maximum radius of fifth cam is less than maximum radius of first four cams by value equal to half the working stroke of first three cams. Working stroke of cams in working part of pipe ranges between 0.55 and 0.7 of pipe inner diameter before pipe section is overlapped. EFFECT: increased efficiency by reduced pulsation of liquid at apparatus output end without increasing the moment on shaft of actuating engine and provision for employment of polyvinyl chloride pipes without usage of special silicone inserts. 5 dwg