Gas-driven device for delivery of flowable media comprises a piston provided with a valve controlled bypass bore, and a rubber-elastic membrane bag which along its edge is joined gastight to the piston

Gas-driven device for delivery of flowable media, with a piston (3), a delivery nozzle (5), a closure head (4) and a gas generation system (6, 7, 8, 9) is characterized by e.g. the fact that the piston is provided a bypass bore and with a rubber-elastic membrane bag which along its edge is joined gastight to the piston. Gas-driven device for delivery of flowable media, with a piston (3), a delivery nozzle (5), a closure head (4) and a gas generation system (6, 7, 8, 9) is characterized by the following facts: (a) the piston is provided a bypass bore and with a rubber-elastic membrane bag which along its edge is joined gastight to the piston; (b) the bypass bore has a valve which is shut when the piston moves from the nozzle (5) to the closure head (4) to suck in flowable media; and (c) the valve is opened when the medium from the device is to be delivered by means of driver gases. Die Erfindung betrifft eine gasbetriebene Fördervorrichtung, zum Beispiel zur Förderung von Schmierfett oder zur Injektion pharmazeutischer Lösungen, vorzugsweise mit Gasentwicklungszellen als Antriebsmittel. Sie besitzt einen mit dem Kolben verbundenen, zusammengefalteten Fördersack, der sich bei der Gasentwicklung entfaltet und die Verdrängung des zu fördernden fließfähigen Mediums aus dem Zylinder übernimmt.