DEVICE AT A SPRAY NOZZLE

Abstract: The present invention relates to a device at a spraying nozzle (2). The spraying nozzle (2) is arranged to disperse a compressed fluid and is arranged at the external, free end of a tube (1) and comprises a disc means covering the opening of the tube channel. This is done by a flexible material with a slot (2b) extending diametrically to it, which slot is arranged to open under the effect of the compressed fluid. Characteristic for the invention is that said disc means consists of a diaphragm (2a) with a thickness in the order 200 - 500 mu m.

Description: Device at a Spray Nozzle The present invention relates to a device for a spraying nozzle arranged to spray a compressed fluidτ which nozzle is arranged at the external, free end of a tube and comprises a disc means covering the opening of the tube channel, the disc means being of a flexible material with a slot extending diametrically to it and arranged to open under the effect of the compressed fluid- Nozzles of a known type for spraying purposes are so designed that the fluid will perform a turbulent movement, which results in a fine dispersion of the fluid. This design comprehends that the nozzle has an external diameter that is many times larger than the external diameter of the tube. In many applications, e.g. when to finely disperse liquid anaesthetics in the nose and throat the treatment with such a relatively large nozzle is experienced as unpleasant. The French published specification No. 2 418 674 discloses a new application of an earlier patented safety valve, namely to create artificial fog. The valve is located in the point of a feeder and shows a pile of rounds of an elastic material, each of which rounds having in its center a cut which normally is closed but opens through deformation of the rounds under the effect of pressure. Between each group of two closely located rounds a disc is inserted, which disc is formed with a central opening and is made of a mterial that facili¬ tates sliding due to the relative deformation of the elastic rounds. In its new application the valve operates at pressures in the order 30 to 40 bars and can be dimensioned for still higher pressure by increasing the number of piled rounds. The present invention is intended to be used in applications with overpressures up to 10 bars. In the aforementioned published specification there are no directions as to how the valve could be modified in order to be capable of handling such low pressures as are intended in the present invention. SUBSTITUTE The object of the present invention is to provide a nozzle, at a low cost, whose external dimension is equal to that of the tube and which is appropriate in such applications as for example fine dispersion of liquid anaesthetics for intermittent spraying of the nose or the throat. It is here a matter of pressure blows of less than 10 bars, as mentioned, and which have a duration of a few seconds. This is achieved according to the invention in that said disc means consists of a diaphragm with a thickness in the order 200 - 500 urn. Further advantageous characteristics of the invention will be evident from the following description with reference to the accompanying drawing, in which Fig. 1 is a longitudinal section of the external end of a tube with a nozzle according to the invention unaffected of fluid pressure. Fig. 2 shows the nozzle according to Fig. 1 exposed to a compressed fluid. Figs. 3a and 3b show in the tube axis direction two alternative embodiments of a slot opening. I the drawing, 1 designates a tube, which in its external, free end has a nozzle, in the drawing generally designated by 2. The nozzle 2 has as its purpose to finely disperse a compressed fluid in a con¬ tainer, not shown in the drawing, to which the tube 1 is connected. The fluid pressure is achieved for example by means of a pump connected to the tube between the container and the nozzle or through overpressure in the container. According to the invention the nozzle 2 consists of a thin diaphragm 2a, which covers the opening in the tube channel and which has a slot opening 2b that extends diametrically over the opening of the tube channel. The diaphragm 2a is made of a flexible material, and the slot opening contributes to the fact that the diaphragm, under the effect of the fluid pressure, will take such a nozzle form suitable for dispersion of the fluid which is shown in Fig. 2. Here, there should be a relationship between on one hand the thickness and elasticity of the diaphragm 2a and on the other hand the fluid pressure such that the slot opening remains closed as long as the fluid pressure does not exceed a certain value. When the fluid pressure exceeds this value the slot opens approximately instantane¬ ously and contributes in giving the diaphragm in the area nearest to the slot opening a suitable nozzle form for dispersion of the fluid. In the mentioned relationship between the elasticity of the diaphragm and the fluid pressure at which the slot opening opens the thickness of the diaphragm, as mentioned, is included as a factor. The thick¬ ness should be in the order 200 - 500 μm. However, it is essential that the diaphragm is sufficiently thin so that the fluid pressure can cause it to take the cross-section form shown in Fig. 2 which guarantees fine dispersion of the fluid. As is known, every tube length corresponds to a fall of pressure. The fall of pressure which is associated with a long tube may be compensated for by a thinner diaphragm in proportion and vice versa.

Claims: Claims 1. A device at a spraying nozzle (2) arranged to disperse a com¬ pressed fluid, which nozzle (2) is arranged in the external, free end of a tube (1) and comprises a disc means covering the opening of the tube channel, which disc means is made of a flexible material with a slot (2b) extending diametrically to it, which slot is arranged to open under the effect of the compressed fluid, c h a r a c t e r i z e d in that said disc means consists of a diaphragm (2a) with a thickness in the order 200 - 500 urn. 2. A device according to claim 1, c h a r a c t e r i z e d in that the slot (2b) is straight. 3. A device according to claim 1, c h a r a c t e r i z e d in that the slot (2b) is S-shaped.

Inventors: NILSON BILLY, NILSON, BILLY
Applicants: CENOVA AB
Application year: 1990
Main classification: B05B1
IPC codes: B05B1