The invention relates to a pump cylinder a) in which a pump plunger is guided which divides the cylinder into a forward and a rearward subspace, b) which, in the forward subspace, has a connection for taking in the medium to be delivered, c) the rearward subspace of the pump cylinder having one or several electrochemical gas consumption cells for a consumption gas and d) an electric circuit being provided, which is constantly or temporarily connected with the electrodes of the gas consumption cell, as well as to a process.
In U.S. Patent Document U.S. Pat. No. 1,500,975, a machine is described which consists of three mutually connected cylinders and three plungers which are guided therein and are rigidly connected with one another. The three cylinders have different diameters. While the master cylinder is moved back and forth by a reciprocal admission of a vacuum and of atmospheric pressure to the spaces divided by the plunger, the two other cylinders and the plungers synchronously moved therein are used for the step-by-step compressing-on of air. In British Patent Document GB-PS 911,493, a lubricant dispenser is described. In the case of the latter, a lubricant pump presses the lubricant into a ring-shaped pipe which supplies one or several lubricating points. The ring-shaped pipe guides, by way of a pressure control valve, the excess lubricant back into the storage tank.
Systems are known and sold, by means of which pasty masses and liquids can be continuously delivered. In one of these systems (PERMA grease dispenser of the firm G.
Satzinger in Bad Kissingen), a cylindrical body is divided into two subspaces by a membrane acting as a plunger. One subspace contains the medium to be delivered which is supplied by way of the spout mounted at one end. The second space contains a gas generating device which continuously generates hydrogen from a corrosion element. As a result, a pressure is built up, the plunger is displaced and the medium to be delivered is pressed out of the spout.
In that system, the corrosion element consists of a round zinc blank with a soldered-in molybdenum rod. When activated, it is charged into a caustic potash solution. Thereby the implementation of the gas generation is defined in a constant manner. It is a function of the temperature. The delivery speed itself is also a function of the counterpressure at the spout because, when the gas generating rate is constant, the volume production of the hydrogen is inversely proportional to the pressure.
With respect to a short-circuit element, the cell generating the hydrogen, as described in German Patent Document DE-PS 35 32 335 A1, offers the advantage that the generating of hydrogen can be precisely controlled by way of a resistor to be controlled from the outside. This cell consists of a variant consisting of a zinc anode and of a hydrogen cathode with caustic potash solution as an electrolyte and a separator which separates the anode and the cathode. In another variant of the cell, it generates oxygen as the propellant, in which case a reducible electrode, for example, of manganese dioxide MnO2 or AgO or another metal oxide, is used as the countercathode. An oxygen precipitation electrode is used as the anode. It is characteristic of the gas generating electrodes in both cases, for oxygen as well as for hydrogen, that the electrode material has an overpotential for the gas to be generated which is as low as possible, for which in both case Raney nickel and activated carbon can be used as a catalyst.
In German Patent Document DE 36 21 846 A1, a delivery system is described in the case of which the liquid to be delivered is transported by way of one or a plurality of pores in a body which is lyophobic with respect to the liquid to be delivered. This measure, which divides the delivery flow into a current of discrete drops, represents a pressure lock which makes the delivery flow less dependent on the counterpressure. This pressure lock may be arranged on the oncoming flow side and on the outgoing flow side between lyophilic porous bodies and may communicate with the latter.
Such delivery devices can be used in multiple manners. For example, the injection of insulin solution or other medications into the body by means of such delivery devices was suggested. An earlier invention (German Patent Document DE 3711714 C2 of Apr. 7, 1987) had the object of further developing a system of the initially mentioned type such that the delivery speeds can be predetermined and controlled and that the generating of the vacuum takes place by means of devices which are as simple as possible. The essence is a driving motor which consists of an essentially rigid driving cylinder with a driving plunger movable therein or a membrane acting as a plunger. In the starting condition, this driving cylinder is filled with an electrochemically effective gas, such as hydrogen or oxygen under atmospheric pressure. Inside this driving cylinder, a gas consumption cell is situated which has a gas consumption electrode and a suitable counterelectrode, which are arranged in a cell vessel. Between the electrodes, a separator is situated which has a suitable electrolyte. The contacts of the two electrodes are accessible outside the cylinder space or are to be operated from the outside.
When the closing takes place by way of an outside close-down circuit, a current flow is generated in the cell which per time unit consumes an equivalent quantity of the reaction gas and thereby generates a vacuum with respect to the outer atmosphere. This vacuum causes a movement of the driving plunger so that the latter can carry out an outside work operation.
In the case of the delivery system according to German Patent Document DE 3711714, the work operation consists of the movement of a pump plunger in a pump cylinder which preferably rigidly connected with the driving cylinder of the driving motor. The pump plunger is preferably also rigidly connected with the driving plunger of the driving motor. This pump cylinder contains the liquid to be delivered which, by means of the coupled movement of the two plungers is pressed out by way of the delivery spout or by way of a pressure lock.
Based on the existing state of the art, the invention uses a different approach which has not been recognized in that it designs and utilizes the pumping cylinders known per se for collecting many different types of samples. The invention achieves this by means of the following. Accordingly, the rearward part of the pump cylinder is filled with the gas which can be electrochemically consumed, and the electric circuit is designed for causing such a current that the gas is consumed, and the pump cylinder forms a device for collecting pasty masses, liquids, gases and mobile objects for a previously definable time period.
Although the present invention follows part of the teaching of German Patent Document DE 3711714 C2, in contrast to the latter, its object is not the distribution of fluid media but their collection. In many areas of manufacturing control, environmental production, medicine and biology, samples of pasty, liquid, gaseous substances or of mobile objects have to be collected, stored and tested, in which case the time periods for the collection of samples may be hours and months. This will be demonstrated by several examples:
Waste water from many large and small enterprises is led into the public sewage system. Proof of the introduction of toxic substances can be obtained only by a continuous sampling and the analysis of the samples.
The collecting of gas samples in the case of conversions in technical equipment also permits the clarification and the control of reaction sequences in gases.
The collecting of milk samples of automatically milked cows permits the determination of the average values of an animal""s fat production. Samples of the body fluids of human beings and animals are also often helpful when diagnosing diseases.
The collecting of small animals and microbes in forests and fields and the collection of air samples in high-pollen seasons fall into the biological field.
In the food production field but also when monitoring the biology of bodies of water, the proof of germs or their exclusion by collecting samples is also of interest.
In a simple manner, the invention now provides a device for collecting pasty masses, liquids, gases and/or other mobile objects which permits the collecting of samples for a previously definable time period.
An advantageous constructive variant of the invention is characterized in that the consumption gas and the consumption cell in the driving cylinder are enclosed by a deformable plastic foil.
According to another preferred embodiment of the invention, the consumption gas contains oxygen and the consumption cell contains, in addition to a gas diffusion electrode for oxygen, an accumulator electrode as a counterelectrode, preferably in an alkaline electrolyte solution.
Particularly preferably, for ensuring the secure functioning of the device, a valve is present in the take-in pipe, which valve opens in the suction direction in the case of a vacuum and has a shut-off effect in the outflow direction in the case of excess pressure.
According to another particularly advantageous further development of the invention, the electric circuit is designed such that it permits a current flow in the consumption cell or cells only in the voltage window in which the gas consumption takes place and shuts off the current flow in the remaining voltage ranges. This ensures in an uncomplicated manner that the pump cylinder is operated only in the xe2x80x9ccollection and suction modexe2x80x9d.
The electric circuit preferably contains an optical or acoustic signal generator which generates its signal when the current flow takes place in the voltage window which permits the gas consumption.
According to another advantageous variant of the invention, a starting resistor is present in addition to the adjustable working resistor, by way of which starting resistor the consumption cell will be short-circuited until the movement of the plunger starts. A manual switch or a pressure switch is also preferably provided for switching off the starting current and responds to the pressure difference at both sides of the plunger or to the movement of the plunger from the starting position of the plunger in the cylinder.
Generally, a consumption gas is used which is as pure as possible in order to utilize the full plunger stroke. However, by adding an inert contamination, the collecting operation can be limited because the inert gas remains in the plunger as residual gas.
Advantageously, time switches, photoresistors and/or photocells can be arranged as controlling components with additional direct-current cells in the electric circuit of the driving insert. As a result, the collecting operation can be limited to certain times of day, light conditions and/or other situations.
The invention also provides a process for collecting samples, particularly pasty masses, liquids, gases and/or other mobile objects, during a previously determinable time period in a pump cylinder characterized by filling the rearward subspace of the delivery cylinder with the consumable gas, by connecting an intake pipe in the forward cylinder space with the sample with the sample space, and by adjusting a consumption current in the gas consumption cell which, per time unit, consumes the volume of the consumption gas which is equivalent to the sample rate.
Following the sampling, an analysis of the content layered corresponding to the time-related removal and/or a mixing of the content and its analysis can then take place.
The invention preferably provides a process for collecting mobile biological objects during a previously defined time period in a pump cylinder according to the invention, in the case of which the charging of a pilot medium into the forward cylinder space takes place before the consumption current is switched on.
In a further development of the invention, a medication is preferably fed to a limited body region of a living thing (for example, an organ), and, after a predetermined time period, the medication and/or other body fluids are at least partially withdrawn again from the limited body region by means of a pump cylinder according to the invention. In this case, the invention is particularly suitable for feeding to a limited body region of a living thing (for example, an organ) an overdose of a medication by means of a syringe and to withdraw this xe2x80x9coverdosexe2x80x9d again from the limited body region by means of a xe2x80x9csuction pumpxe2x80x9d according to the invention.
The pump cylinderxe2x80x94for example, in the form of a syringexe2x80x94is closed on top preferably by the insert which, fixed in the cylinder, may, for example be sealed in and off by an O-ring and/or be screwed to the pump cylinder. A suction insert and/or driving insert, which is also sealed off by means of an O-ring, is pushed into the insert.
The driving insert contains the at least one gas consumption cell or several of these cells in a series or parallel connection. In addition, there is the Zener diode in a series connection or a diode with a corresponding threshold voltage.
The driving insert has two positions which are characterized by a bore. This bore leads into the driving insert and permits the feeding of the consumption gas into the cylinder space, in which case the plunger is driven from its uppermost position into its lowermost position. Subsequently, the driving insert is pushed into a waiting position in which the bore of the driving insert is closed. After the activation of the driving insert, the current will flow which binds the consumption gas, pulls up the plunger and causes the collection operation to take place according to the invention.
The plunger may have a bore which may be closed by a frit.
After the bore was utilized for charging the consumption gas, it is closed by means of a wetting liquid.
Additional embodiments of the invention of the invention are contained herein.
In the following, the invention will be explained in detail with reference to the drawing by means of embodiments.