Dragerwerk Aktiengesellschaft

Scato Albarda

Ulrich Heim

Werner Thoren

Alfred Eder

Johann Otten

Stefan Kahning

Peter Vehrens

Johannes Lagois

Hansjochen Schuck

A valve arrangement from microstructured components worked out of a basic body, for the control of fluids, include an actuation element which is movable relative to a flow path distributor and opens or closes fluid paths depending on its position. A transition from one position into the other is effected by adding an actuating drive connected to an electrical power source. The actuation element is held in its switch position. For a high fluid flow, a large force can be applied to the actuation element. The actuating drive works according to an operating principle aimed at covering the longest distance possible. A holding device is provided, which works according to an operating principle working independent of the first operating principle and provides the generation of the greatest cohesion possible.

Valve arrangement of microstructured components

The invention is directed to an apparatus for determining the proportion of substances having paramagnetic characteristics, such as oxygen, in a mixture of substances. The apparatus has a housing and the mixture of substances is passed along an arrangement of four magnetic field sources by a rotatable cuvette arrangement mounted in the housing. The apparatus is improved in that the effect of external disturbing influences on the penetration of the cuvette by the magnetic field is reduced and so that the measuring characteristics are independent of the position of the plurality of magnetic field generating units. For this purpose, the arrangement of the magnetic field sources is simply disposed at one side of the housing lying opposite to the rotating surface of the cuvette arrangement facing toward the drive shaft. The arrangement of magnetic field sources includes a carrier plate on which the magnetic field sources are accommodated and carry respective measuring field coils. The magnetic field sources face with their end faces toward the cuvette arrangement.

Apparatus for determining the proportion of a substance having

The invention is directed to a sensor for making capacitive measurements of the pressure in gases and contains two measuring electrodes conjointly defining a capacitor and arranged in spaced relationship to each other. This sensor is improved such that a pressure measurement is possible without deformable parts. Long-term drift free measurements can be carried out with even the smallest electrode spacing being realized so that miniature sensors can be provided. The intermediate space between the electrodes is accessible to the gas to be investigated and has electrically insulating spacers between the electrodes. The spacers determine the spacing between the electrodes and maintains the electrode spacing during the measurement.

Sensor for capacitively measuring pressure in a gas

A device for the determination of the concentration of substances with paramagnetic properties, particularly oxygen, in substance mixtures comprises a cell assembly divided into several chambers, which is arranged to revolve with relation to a service for producing a magnetic field penetrating the cell assembly, and a coil assembly associated with this assembly for the conversion of the magnetic induction produced in it by the paramagnetic substance into an electrical signal. The assembly of devices producing magnetic fields and their associated measuring field coils is unaffected by external interferences such as transfer of mechanical vibrations or influences of external magnetic fields. For this purpose, at least four or more, even number of devices producing magnetic fields with their respective measuring field coils are arranged on both sides of the cell assembly and symmetrically to the axis of rotation, on a common housing, and the magnetizing polarity of the devices is combined with the magnetizing polarity of their respective measuring field coils in alternating orientation.

Magnetic field producing device for determining the concentration of a

The invention is directed to an arrangement for generating a gas mixture. The arrangement includes a vaporizer which is switched into a vaporizer line which starts at a supply line and opens into a user line with the vaporizer line being bridged by a bypass line. The influence of material parameters associated with the metering of the vaporized gas quantity is reduced. For this purpose, the vaporizer line is alternately interrupted at the input and the output of the vaporizer and, when interrupted at the output side, the user line is interrupted by means of a switching element arranged therein.

Arrangement for controlling a vaporizer by means of pressure fluctuations

A device for the determination of the concentration of substances with paramagnetic properties, particularly oxygen, in substance mixtures comprises a cell assembly and devices to produce a magnetic field as well as to measure changes in the magnetic induction. Great mechanical accuracy and stability in the measuring of a change in the magnetic induction uninfluenced by external disturbing fields or by mechanical changes due to external temperature fluctuations or vibrations with a coil assembly for producing a magnetic field and for measuring the induction signal comprising self-contained coil carriers, which, surrounding a cell assembly and are arranged respectively at a distance from the axis of rotation of the cell assembly.

Device for determining the concentration of substances having

The invention is directed to an electrically-actuable valve for a fluid such as a gaseous medium. The valve has a valve closure member disposed adjacent a valve plate provided with a plurality of pass-through openings. The valve closure member and the valve plate are displaceable relative to one another in a direction perpendicular to their surfaces by means of a short-stroke drive whereby a plurality of sealing lines are opened. To arrive at a good valve operation especially for relatively small valves, the valve plate is configured with a plurality of pass-through openings or perforations. The surface of the valve plate facing the valve closure member has a plurality of raised portions formed thereon defining respective receiving surfaces for receiving the closure member in contact engagement therewith to form the sealing lines when the valve is in the closed position. Each two mutually adjacent ones of said raised portions define a flow channel open toward the closure member and communicating with the outlet of the valve. The pass-through openings lie within the raised portions and extend from the other side of the valve plate to the receiving surface and communicate with the channels when the valve is open and the valve closure member is displaced away from the valve plate thereby enabling the gaseous medium to flow from the inlet of the valve to the outlet thereof.

Electrically-actuable valve

A piston proportioning pump for liquids, with a piston in a cylinder, an uptake and discharge valve and an oscillating drive is improved so that the formation of vapor bubbles or of a low pressure during the suction phase is prevented even when the pump space is filled quickly. The dead space of the piston proportioning pump still remains so small that a largely complete expulsion of the proportioned amount through the discharge valve is guaranteed. To this end, provisions are made so that the discharge communicates with the pump space within an uptake valve.

Piston proportioning pump

A device for admixing liquid anesthetics into the respiratory gas to be supplied to a patient makes it possible to monitor the concentration, the flow of respiratory gas, the mixture ratio, and the flow of anesthetic. Errors may thus be indicated and safety is increased in medical practice. The device utilizes the phenomonen that during the evaporation of an anesthetic admixed with the respiratory gas, the temperature in the thermally insulated ambience of the mixing chamber drops by an amount depending on the ratio of the vaporized anesthetic to the respiratory gas, thus on the concentration. The temperatures are measured at the inlet of the mixing chamber by an inlet sensor and an intermediate sensor, and at the outlet of the mixing chamber by an outlet sensor. Upon heating the stream of respiratory gas by means of a heating element in the inlet portion, the breathing gas flow, its mixing ratio, and the flow of anesthetic can be measured, and thus the concentration can be determined from the necessary heating power input and the heating temperature. The measurement is effected by a heater control and evaluating circuit connected to the sensors and the heater, by which heater controlling measures are effected upon deviations from desired values.

Device for evaluating the mixing of liquid anesthetic and a respiratory

In volumetric dosing of liquids, equal mounts of a liquid must be added in equal time intervals to a primary flow which may consist of either liquid or gaseous substances. This is done most accurately by means of piston pumps as dosing pumps. The dosing pump according to the invention affords simple design and reliable operation. The piston stroke is fixed by means of a collar in a limiting chamber. The compensation required to prevent double fits and compensates for wear, tolerances, etc. is obtained by an elastic length equalizer in the connecting rod. This arrangement leads to being normally represented as a rigid connection which, however, in the two end positions of the piston, when the forces rise suddenly due to the collar striking the limiters, equalizes these forces over the length.

Dosing pump for liquids

An apparatus is disclosed for admixing anesthetic with respiratory gas to be supplied to a patient, which comprises a mixing chamber having an inlet for receiving the liquid anesthesia and the respiratory gas, and an outlet for supplying the mixture. A feed line is provided in the inlet for the liquid anesthesia, with a heat exchanger for equalizing the inlet temperatures of the anesthesia and respiratory gas. Temperature sensors are provided in the inlet and the outlets with a circuit for determining the difference between the temperatures. Without heating of the chamber this difference is proportional to a ratio between the evaporated anesthetic and respiratory gas. With the chamber heated to equate the inlet and outlet temperatures, the amount of heating is proportional to the flow of anesthetic to the chamber.

Apparatus for admixing liquid anesthetics and respiratory gas

A sensor for sensing the presence of oxygen in a test gas mixture comprises either first or second tubes for the separate flow of a measured gas and a gas to be tested for a single tubular arrangement for the successive flow of these two gases in association with a plurality of radio-frequency coils which are connected in an electrical bridge circuit to that they can be balanced in any variation of the inductance measure. Since oxygen in the gas produces a paramagnetism which provides induction variations in the coils of the balancing circuit, the variations of the balancing circuit may be used to sense the proportion of the oxygen content in the gases. With the inventive method the gases are passed into association with the balancing circuit and variations of the test gas from the measured gas are sensed by the circuit balance which is produced by the oxygen which is present in the gas mixtures. Such a sensor may be used for breath protection, diving and medical fields.

Method and apparatus for sensing the presence of oxygen in a gas mixture

A valveless dosing pump is disclosed which comprises a housing having a cylindrical bore therein with a plurality of hard material rings press-fit into the bore and spaced from each other to leave annular inlet and outlet spaces. First and second pistons are slidably mounted within the rings and the housing is provided with inlet and outlet conduits communicating with the inlet and outlet spaces. The first piston is connected to a drive unit which moves the first piston through a complete stroke between the inlet and outlet spaces. The driving unit also abuts the second piston which moves through part of the stroke of the first piston and in the same direction. The difference between the strokes of the first and second pistons comprise a dosing volume. The rings are made of a suitable low friction dense and hard wear-resistant material, such as, silicon carbide or silicon nitride.

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Gross Schenkenberg, Germany

Scato Albarda