Valve for liquid pumps

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.

Description

FIELD OF THE INVENTION[0001]The invention relates to a valve assembly for fluids, in particular for liquids, and includes a housing, which has an elastic valve membrane mounted in the housing and a valve body held in the elastic valve membrane. The valve assembly includes an inlet for the fluid, opening into a chamber, and an outlet leading out from the chamber, it being possible to bring the valve body into contact with the elastic valve membrane to close the fluid passage portion of the valve.[0002]The valve is preferably used in a mechanically operated liquid pump, particularly in a liquid pump provided for medical and nutrient liquids, and for liquids in the biological and laboratory sector. It is also conceivable to use the valve for gases, particularly those that have to be delivered in the context of laboratory tests. The main field of application of the valve is in the delivery of a liquid.BACKGROUND OF THE INVENTION[0003]Many different types of liquid pumps are used to deli...

AI Technical Summary

Benefits of technology

[0013]It is a particular advantage of the valve according to the invention that the flow of liquid can be kept substantially constant, irrespective of how great the inlet pressure is on the valve. This is possible because of the fact that a pressure arising at the outlet causes the valve membrane to curve outward from its starting position, with the result that the valve membrane is moved against the stop and in this way experiences a deformation, which leads to the closure of the valve body. The relatively high pressure in the area of the outlet, which is of course lower than the pressure in the area of the inlet, is ensured by the flow restrictor.

[0016]The valve body is preferably a rigid structural part. It is held in the valve membrane in such a way that it cannot be moved relative to the latter in the direction of movement of the valve body, or in its transverse direction, and, in particular, can also not be rotated with respect to the valve membrane. This ensures that the inlet channels of valve membrane and valve body are aligned in each operating state and, in addition, ensures a defined position of the valve body to the valve membrane, particularly in the area in which the valve body is intended to be closed by the valve membrane. The valve membrane is preferably held in the area of a circumferential edge between two parts of the housing, and in particular is held there by clamping. This affords the possibility of the valve membrane, starting from the edge areas, being able to bulge out sufficiently under the effect of the respective fluid pressure. The valve membrane is preferably profiled in cross section, and a central area of the valve membrane serves to receive the valve body. This central area has a pot-shaped configuration in particular.

[0021]With the valve according to the invention, the flow of the fluid is regulated in relation to the maximum pressure. The valve membrane is preferably configured with respect to the pressure level to be regulated. This means that the regulation can be effected entirely by means of the elastic valve membrane. According to a development of the invention, however, a spring is provided for resetting the valve membrane to the open position of the valve. This spring assists the resetting movement of the valve membrane.

Problems solved by technology

This is possible because of the fact that a pressure arising at the outlet causes the valve membrane to curve outward from its starting position, with the result that the valve membrane is moved against the stop and in this way experiences a deformation, which leads to the closure of the valve body.

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