The use of a disconnector for the protection of the main water supply in medical plants

Abstract: The present invention concerns a disconnector for the protection of the watermain, for use in particular in medical plants. The disconnector comprises an air diaphragm which is interplaced between the watermain and the medical plant which uses water taken from the watermain, thus keeping them separate under every kind of operative condition, and in this way preventing any passage of pollutants out of the plant into the watermain.

Description: The invention relates to the use of a disconnector for the protection of the mains water supply, with application in medical plants as set out in the claims. In medical plants, and in particular during dental bridgework, it is frequently necessary to use water from the mains water supply; a typical instance, which will be used during the following description and which is to be considered not as an indication of the limits of the disconnector but purely as an apt example, is the liquid ring pump in aspirating dental instruments. These pumps are used to aspirate fluids that naturally abound in bacteria and pollutants. For this reason it is absolutely necessary, and in many cases a legal requirement, to prevent these bacteria and pollutants from getting into the mains water supply; this can happen both in cases of malfunction of the pump (for example, through accidental function inversion) and during times when the pump is not in use. In order to avoid such accidents filters are sometimes used, which are quite effective as regards pollutants, but which produce unsatisfactory results as far as bacterial pollution is concerned. Also used for this purpose are complex-type valves which prevent the return of the fluid towards the mains water supply in the case of syphoning or flow inversion. However, even these valves do not guarantee absolute security with regard to halting the bacteria which, even if only in certain circumstances, can reach the mains water supply. In patents EP 0300639 A1 and US 4344756 disconnectors are described located between the mains water supply and utilisation plant; however, none of the said disconnectors is able to eliminate all mechanical contact between the mains water supply and the utilisation plant. The aim of the invention is to eliminate the above-described drawbacks by providing an instrument which absolutely prevents the introduction of bacteria and other pollutants into the mains water supply. A further aim of the invention is to provide a disconnector of simple and economical construction which can be installed in existing plants. These aims and others besides are attained by the disconnector in question, made according to the specifications indicated in the claims. A notable advantage of the invention is that it permits recycling of the water used by the medical plant. Further characteristics and advantages of the invention will emerge during the detailed description that follows, whose aim is simply to provide an example of the disconnector in question's possibilities, and not to indicate its limitations. The disconnector envisages, in essence, the use of an air diaphragm which is interposed between the mains water supply and the medical plant which uses water from the main. In this way, either in the case of an interruption in the drawing of the water, or in the case of syphoning or flow inversion, a secure barrier exists which prevents both bacteria and any other pollutants from penetrating into the mains water supply. This does not occur with the systems with valves and filters adopted up to now, where the very external structure of these elements constitutes a mechanical connection between the mains water supply and the plant which in some cases permits the passage of bacteria or pollutants. The air diaphragm is created in a simple way, using a tank which is filled, generally by free fall, with water coming from an inlet situated in the mains water supply. The free surface of the water is constantly maintained below the inlet; floats or other systems already in common use would probably be employed for this purpose. Water is taken from the tank for use in the medical plant. This operation may be performed by means of a pump, or by free fall if the tank can be placed higher than the medical plant. During normal functioning, water falls into the tank and is sent to the medical plant. It has been evidenced that neither bacteria nor pollutants are able to find their way up the resulting jet and into the mains water supply. In the case of an interuption in water erogation, an air diaphragm is created between the inlet and the tank; this diaphragm prevents the passage of bacteria and pollutants from the water in the tank (which could contain such pollutants since it is connected to the medical plant) into the mains water supply. Also in the case of syphoning or flow inversion, eventual bacteria and pollutants coming from the medical plant could reach only the tank; neither bacteria nor pollutants can, under any circumstances, penetrate into the mains water supply. Using the disconnector in question it is also possible to take the water coming out of the medical plant and reintroduce it, by means of a recycling conduit, into the tank, so that it can be used again. A disinfection device of a type in common use might be placed on the conduit which could therefore disinfect the recycled water if this should contain percentages of bacteria or pollutants above a predetermined limit. The disinfection operation, even if not strictly necessary since the recycled water never comes into contact with the mains water supply, is particularly useful in cases in which a closed-circuit recycling plant is envisaged, where the mains water supply, once the plant is filled with water, is used only for occasional small refills of the water in the tank. The possibility of effecting the recycling of the water used by the medical plant, or indeed of using a closed-circuit recycling plant, represents a remarkable advantage of the disconnector in question both as regards water-consumption and with respect to the quantity of water which is sent to the drains, thus reducing pollution there. Notwithstanding its apparent simplicity, the disconnector in question provides the solution to a great problem which up to now had never been completely solved using the devices available.

Claims: Use of a disconnector connectable between a main water supply and a medical plant which uses water from said main water supply, for preventing introduction of bacteria and other pollutants into the main water supply, wherein a tank is used, which can be filled with water coming from an inlet situated in the mains water supply; the water can be taken from the tank for use in the medical plant; the water in the tank having a free surface which is constantly maintained at a level below a level of the inlet, in order to create an air diaphragm between the inlet and the tank. Use of a disconnector as in claim 1, characterized in that means are provided for reintroducing water coming out of the medical plant into the tank.

Inventors: CATTANI AUGUSTO, CATTANI, AUGUSTO
Applicants: CATTANI SPA, CATTANI S.P.A.
Application year: 1990
Main classification: A61C1
IPC codes: A61C1