Abstract: The invention relates to a valve (32) for a fluid, in particular for a liquid, with a housing (3, 4), which has a flexible valve membrane (33) mounted in the housing and a valve body (34) held therein, and with an access point (26, 37, 38, 39) for the fluid, which opens into a chamber (42, 43, 44), and an outlet (45) leading out of the chamber, it being possible to bring the valve body into contact with a flexible element (33) in order to close the fluid passage of the valve. According to the invention, in a valve of that kind the flexible element is the flexible valve membrane (33) and a stop (36, 55) is used to limit the extent to which the valve membrane curves outwards during an increase in pressure in the fluid, the stop moving the flexible element (33) against the valve body (34) and closing the fluid passage of the valve.

Abstract: The invention relates to a mechanically operated liquid pump (1), particularly for medical or nutrition-physiological liquids, with a housing (2) and with an expandable clastic element (16), which is held therein and which serves to store and deliver the liquid, and with a closeable access (21) and exit (50) for the liquid from the elastic element as well as with a device for largely constantly maintaining or limiting the liquid volume flow discharged by the elastic element. According to the invention, the following features are provided: the elastic element is provided in the form of a balloon (16) that has an opening (17a); a core (11) is housed inside the housing and is inserted into the balloon via the opening; means (20) for fastening and sealing the balloon in the area of its end having the opening are provided on the core or on the housing, and; when relatively unstressed, the balloon rests against the core at a distance from its fastening.

Abstract: A mechanically operated liquid pump for medical and nutrient liquids, as well as for liquids used in biological and laboratory applications, has an integrated, self-contained pump construction comprising a housing having an expandable elastic member mounted wholly within the housing and shaped to store and dispense a liquid therefrom. Inlet and outlet members are also mounted within the housing, are operably connected with the elastic member inside the housing, and regulate the flow of liquid traveling into and out of the pump. A flow regulator is also mounted wholly within the housing, communicates with at least one of the inlet and outlet members, and maintains a substantially constant volumetric flow of liquid dispensed from the elastic member.