A SPRAY MEANS FOR A CONTAINER FOR A LIQUID TO BE SPRAYED

Abstract: A spray means for a spray can or bottle, the latter being adapted for containing a liquid to be sprayed, a pressurised gas being present in the space above said liquid, a dip tube (5) extending into said liquid and being connected, via a dispending valve, with an external spray nozzle (10), a mixing chamber (11') being included between said valve and said dip tube (5), said chamber (11') communicating with said gas space via a communication having a cross-section adapted to the desired gas/liquid ratio, said can or bottle being provided with a one-way valve for filling said space with compressed air, said communication being provided with valve means closed under an elastic force and opening towards the interior of said mixing chamber when the air pressure in said space is sufficient for obtaining the desired mixing effect. In particular said valve means comprises a sealing disc (8'') forming said dispensing valve and closing said communication at the required elastic force when opening said dispensing valve, and said disc (8'') can form, at the same time, the one-way filling valve in the inoperative position of said dispensing valve.

Description: A spray means for a container for a liquid to be sprayed. jr The current spray cans for spraying a liquid com¬ prise a container for said liquid with a pressure space situated above the liquid, as well as a spray head closing said container and having a spray nozzle which is connected, by means of a dispensing valve, with a tube extending downwards to the vicinity of the bottom. In the liquid a driving substance which is, at the normal pressure, a vapour, e.g. freon, is dissolved, and its vapour fills the pressure space so that, when opening the dispensing valve, the liquid is driven through the spray nozzle. The amount of driving substance should be sufficient for allowing the- complete liquid contents to be sprayed in thrs* manner. At each spraying, however, driving substance will be sprayed together with the liquid. Because of the objection." existing against freon, containers of the above-mentioned kind have already been designed in which the pressure space can be filled by means of a pump with compressed air. Apart from the fact that, in thi~_r manner, the use of freon can be avoided, an additional advantage is obtained in that the container, after being emptied, can be filled again with the liquid to be sprayed. In the case of a driving substance dissolved in the liquid and being sprayed together with the liquid, said liquid is divided into very small droplets, and the driving substance will vaporise immediately after spraying. These fine droplets allow a good distribution of a small amount of the liquid over the surface to be sprayed, without the liquid being combined to larger drops whereby the surface to be sprayed would become too wet. When using a driving gas which is not dissolved in liquid form in said liquid, and in particular air, such a so-called dry spraying appears to be not realisable very well, and this less as the liquid to be sprayed has a higher viscosity and/or coherence. This is, in particular, onerous in the case of liquid such as hair varjiish, sun-burn oil or other liquids to be sprayed on the body, and also in the case of lubricating oil, cleaning liquid for electrical contacts and the like, a surplus of which being objectionable or even harmful. All this is a consequence of the fact that the liquid in or beyond the nozzle remains more or less coherent or coalesces to larger drops, whereas, when using a vaporising driving substance, the coherence is broken by vaporisation of the driving substance, so that the small droplets remain in existence. The objection mentioned above is an obstacle for a wider use of spray means operating without a dissolved vaporising driving substance, and in particular air. The invention provides a spray means of this kind which does not show this objection. The spray means according to the invention, which is intended for being arranged on a container for a liquid to be__sprayed, in which container a pressure space for a pres¬ surised driving gas, in particular compressed air, is present above the liquid, said spray means comprising a spray head closing said container ' and having a spray nozzle which, by means of a dispensing valve, is connected with a dip tube extending downwards to the vicinity of the bottom of the container, so that, when opening the dispensing valve, the liquid is pressed by the driving gas towards the spray nozzle in order to be sprayed therein, is characterised in that the dip tube communicates with a mixing chamber which, on the other hand, communicates b means of the dispensing valve with the spray nozzle, and moreover with the pressure space, his in such a manner that, when opening the dispensing valve, a mixture of driving gas and liquid is driven out through said nozzle. By turbulences in said mixing chamber the liquid is mixed with the driving gas, in particular compressed air, the effect being that the desired spraying in the form of small droplets will occur. Said mixing chamber can be a venturi passage con¬ necting with the pressure chamber, and the upper end of the dip tube communicating with the narrow portion of said venturi passage . Preferably the mixing chamber comprises a more or less conical wall, the wider extremity thereof joining the upper wall of he pressure chamber, and said dip tube opening into the smaller extremity thereof, said chamber surrounding the discharge passage towards the spray nozzle, in which wall one or more apertures are provided directly communicating with the pressure space, all this in such a manner that said mixing chamber operates as a whirling space enhancing the intermixing. The connection between the mixing chamber and the pressure space can have such a cross-section in respect of that of the discharge passage and of the dip tube that the correct mixing ratio between gas and liquid will be obtained. In the case of a spray means for a container having a pressure chamber which can be filled by means of a pump or the like with compressed air, the connection between the mix ,ng chamber and the pressure space can be provided with a spring-loaded valve which is only opened as soon as the pressure in the pressure chamber exceeds a given value at which a good intermixing will take place in the mixing chamber In a special embodiment of his spray means, in which the dispensing valve forms a unit with the spray nozzle, whijh valve is opened by pressing inward the nozzle against the force of a spring, which nozzle communicates, by means of a hollow stp , with the interior of said holder, said stem can be shifted by the intermediary of a seal in said mixing chamber, the holder of said stem terminating in at least one lateral aperture which, when not being pressed inwards, is separated from the interior of the mixing chamber by said seal, and by pressing inwards can be shifted beyond said seal into said mixing chamber. In particular said seal is formed by a sealing disc surrounding said stem and bearing against the upper wall of the mixing chamber, said stem being provided at both sides of said disc with a wider shoulder between which the communi- cation opening of said bore is situated, the lower shoulder pressing, in the condition of rest, said disc against the upper wall by the action of the spring. Said sealing disc can extend beyond a lateral wall defining said mixing chamber, said disc being pressed, when pressing inwards said stem, against said wall with the force required for the limiting valve action. Moreover the upperwall of said container can be provided with one or more air entry apertures which are closed under spring force and the internal pressure by said sealing disc . Furthermore said stem can be provided with a coaxial extension peace which, together with the wall of the mixing chamber, defines an annular passage in which the connection with the pressure chamber opens. In some cases an auxiliary element can be used which is adapted to be connected with the supply aperture for com¬ pressed air of said container, which auxiliary element is characterised by a mixing chamber with a coupling peace for making a connection with a water supply, and is adapted for providing therein a substance which is soluble in water for forming a liquid to be sprayed, this in such a manner that water with the dissolved substance can be introduced 'through the filling valve of said holder into said holder by the pressure of the water supply. At the same time the air present in said holder will then be compressed. __, The invention will now be elucidated in more detail by reference to a drawing, showing in: Fig. 1 a diagrammatical cross-section of a spray can for elucidating the principle of the invention; Fig. 2 a simplified cross-section corresponding ith Fig. 1 of an embodiment of a spray can according to the invention ; Figs. 3A and B, respectively, a cross-section of a practical embodiment of a spray can of Fig. 2 and a partial cross-section of the latter spray can in the dispensing con¬ dition; and Fig. 4 a cross-section of an auxiliary element ac¬ cording to he invention. Fig. 1 shows a spray can with a container 1, in which the liquid to be sprayed 2 is provided. Above the liquid 2 an air space 3 is present, which, by means of a filling valve 4, can be pressurised by means of an air pump or the like not shown. A dip tube 5 extends through the uppeπwall 6 of said container into the inner space and to the vicinity of the bottom of said container. At the upper end said dip tube 5 opens ^n o a discharge passage 7 which is closed by mean J s of a alve 8 ith an actuating part 9 , and at the other end thereof a spray nozzle 10 is provided. The discharge passage 7 communicates, at its lower side, with an enlarge¬ ment 11 joining, by means of a valve 12 with a valve spring 13 , the space 3. When opening the valve 8 by means of the part 9 the liquid 2 can be pressed upwards through said dip tube 5 by the pressure in the space 3, and, if the pressure in the space 3 is sufficiently high, the valve 12 will be opened by said pressure. The enlargement 11 forms, together with the passage 7, a venturi passage in which an intermixing of air and liquid takes place by turbulences, so that, through the_ pozzle 10, a fine mist of liquid droplets is sprayed. The spring 13 is, then, adjusted in such a manner that, as soon as the pressure in the space 3 will become insufficient for - effecting such an intermixing, no mist will be dispensed any- more. By means of the air pump the pressure in the space 3 should then be restored. __, Filling the container 1 with the liquid 2 can take place in any suitable manner, for instance by removing the cover 6, and it is also possible to fill by means of the filling aperture 4. The practical embodiment of such a spray can may lead to difficulties. Fig. 2 shows, in principle, an embodi¬ ment of a spray can according to the invention, in which such objections can be avoided. Corresponding parts are indi- cated therein with the same reference numerals as in Fig. 1. Now a mixing chamber 11' is provided within the enclosure 1, and the dip tube 5 opens into that chamber at its lower end. At the upper side a dispenslngvalve 8' is provided which can be opened by means of a spring-loaded actuating part 9, and the passage 7 with the spray nozzle 10 being directly mounted on the wall 6. The mixing chamber 11' con¬ nects, by means of one or more apertures 14, with the space 3, said apertures being closed by means of spring-loaded valves 12' * . When opening the valve 8' an air/liquid mixture formed in the mixing chamber 11' can flow out again, said mixing chamber 11' being shaped in such a manner that a good int •ea-rmixing is obtained by means of turbulences. The valves 12' are loaded by such a spring force that, as soon as the pressure in the space 3 becomes too low, no air will enter to the mixing chamber 11' anymore. Fig. 3 shows a practical embodiment of the principle shown in Fig. 2. The spray nozzle 10' is, now, included in a body 15 which can be shifted in an opening 16 of the cover 6, and is driven upwards by means of a spring 17, a shoulder 18 limiting the upward displacement under the influence of said spring. In this body, which, at the same time, acts as the actuating part 9, a passage 7 is provided which, at one end, terminates in a spray nozzle 10, and, at the other end, joins a transverse bore 19 opening just above the shoulder 18 in the lateral all of a constriction 20. This constriction 20 is, at the other side, delimited by a shoulder 21. Between the shoulders 18 and 21 a valve disc 8" is present which, in the condition shown in Fig. 3A, is pressed against the upper wall 6, and then the connection between the passage 7' through the transverse bore 19 and the interior of the container 1 is interrupted. Said disc 8" extends through an opening 21 in the wall of the mixing chamber 11' , which opening is sufficiently large for providing between its edge and the disc 8", an air passage. The mixing chamber 11' is connected with the wall 1 of the container by means of supports not shown. Furthermore an aperture 4' is present in the upper wall 6 which is kept closed by the disc 8" as a consequence of the internal pressure in the container 1, which aperture can be connected with an air pump or an other source of pressure in order to fill the air chamber 3 of the container 1. At a sufficient overpressure the disc 8" will then be pressed away, so that the supplied air can flow into the container 1. Fig. 3B shows the condition if the body 15 is presse downwards. Said body is then shifted in respect of the disc 8" until the shoulder 21 contacts said disc. The transverse bore 19 will then communicate with the air chamber 3, so that an air/liquid mixture can flow from the mixing chamber 11' towards the passage 7' . The valve disc 8" is, then, pressed against the rim of the opening 21, and will then operate as the valves 12' of Fig. 2. At a sufficient pressure in the space 3, the air can flow from said space towards the interior of the mixing chamber 11' by pressing the disc 8" a little upwards . The lower part 15' of the body 15 is shaped in such a manner that, together with the wall of the chamber 11, a whirling chamber is defined which is adapted to provide an optimal mixing effect. Finally Fig. 4 shows an auxiliary element for a spray can according to the invention, which is intended to be connected with the connections 4 or 4'. This auxiliary elejuent comprises a casing 22 with, at one extremity, a hose coupling or screw nipple 23, adapted to be connected to a water tap. The passage is kept closed by means of a ball valve 24 or the like wi h a compression spring 25, the strength of said spring being adapted to the water pressure. At the other end this auxiliary element comprises a connector 26 to je connected with the connection 4 or 4'. This auxiliary elemen is intended for spraying a liquid consisting of water and a component dissolved there- in, said component being available in the form of a tablet 27 or the like which can be inserted in the interior of the casing 22. When being connected to the water supply, water at the supply pressure can be introduced into the container 1, the component being present in the tablet 27 or the like then dissolving in the water, and, at the same time, the air present in the container 1 being compressed to a pressure depending on the water supply pressure. It will be clear that within the scope of the in¬ vention many modifications can be made. It will, sometimes, al eady be sufficient to provide one or more holes at the lower end of the dip tube 5, said dip tube itself then acting as the mixing chamber.

Claims: C l a i m s 1. A spray mea s, intended to be arranged on a con¬ tainer for a liquid to be sprayed, in which container a pressure space for a pressurised driving gas, and in parti¬ cular compressed air, is present above the liquid, which spray means comprises a spray head closing said container and having a spray nozzle connected, by means of a dispensing valve with a dip tube extending downwards to the vicinity of the bottom of the container in such a manner that, when opening said dispensing valve, the liquid is pressed by the driving gas towards the spray nozzle in order to be sprayed therein, characterised in that the dip tube (5) communicates with a mixing chamber (11) which, on the other hand, commu¬ nicates via said dispensing valve (8) with the spray nozzle (10_,_., and, moreover with said pressure space (3), this in such a manner that, when opening the dispensing valve (8), a mixture of dri ing gas and liquid is dri en outwa ds through said nozzle (10) . 2. The spray means of claim 1, characterised in that the mixing chamber (11) is a venturi passage connecting ith the"*pressure room (3), the upper end of the dip tube (5) opening in the narrow portion of the venturi passage (11). 3. The spray means of claim 1, characterised in that the mixing chamber (11') comprises a more or less conical wall, the widest extremity thereof joining the upper wall (6) of the pressure chamber (3), said dip tube (5) opening into the narrowest extremity thereof, said chamber (11') surrounding the discharge passage (7) towards the spray nozzle in which wall one or more apertures (14, 21) are provided directly opening into the pressure space (3), all this in such a manner that said mixing chamber (11') operates as a whirling chamber enhancing the intermixing. 4. The spray means of any one of claims 1..3, characterised in that the connection between the mixing chambe (11') and the pressure space (3) has such a cross-section in respect of that of the discharge passage (7) and of the dip tube (5) that the desired mixing ratio between gas and liquid is obtained. 5. The spray means of claim 4, intended for a container having a pressure chamber which can be filled with compressed air^-by means of a pump or the like, characterised in that the connection (14, 21) -between the mixing chamber (11) and the pressure space (3) is provided wi h a spring-loaded valve (12' , 8") which is only opened when the pressure in the pressure chamber (3) exceeds a given value, at which a good mixing in the mixing chamber still takes place. 6. The spray means of claim 5, in which the dispensing valve forms a unit with the spray nozzle, which valve is opened when pressing inwards the nozzle against the force of a spring, which nozzle communicates with the interior of the container by means of a hollow stem, characterised in that said stem (15) is slidable by the intermediary of a seal (8") in the mixing chamber (11'), the bore (7) of said stern ending in at least one lateral opening (19) which, hen not being pressed inwards, is separated by said seal (8") fro the interior of the mixing chamber (11'), and, hen pressed inwards, can be shifted beyond said seal (8") into the mixing chamber (11 ' ) . 7. The spray means of claim 6, characterised in hat said seal is formed by a sealing disc (8") surrounding said stem and resting against the upper wall (6) of the mixing chamber (11'), said stem (15) being provided at both sides o said disc with a wider shoulder (18, 21) bet een which the terminal opening (19) of the bore (7) is situated, the lower shoulder (18) pressing, in the condition of rest, under th action of the spring (17) said disc (8") against the upper wall (6) . 8. The spray means of claims 5 and 7, characterised in that the sealing disc (8") extends beyond a lateral fining wall of the mixing chamber (11'), and is pressed, when pressin inwards said stem (15), against a rim (21) of said wall with the force required for the limiting valve operation thereof. 9. The spray means of claim 7 or 8, characterised in -that the upper wall (6) of the container (1) is provided with one or more air supply apertures (4'), which are closed by said sealing disc (8") under the spring force and the internal pressure. • •■ "10. The spray means of any one of claims 6..9, characterised in that said stem (15) is provided with a co¬ axial extension (15') forming, together with the wall of the mixing chamber (11'), an annular passage in which the con¬ nection with the pressure chamber opens. 11. Accessary element for a spray means of any one of claims 1..10, intended to be connected with the supply aper¬ ture for compressed air of the container, characterised by a mixing chamber (22) with a connector (23) for connection with a water supply, and adapted for inserting therein a substance (27) soluble in water for forming the liquid to be sprayed, all this in such a manner that water with the dissolved substance can be introduced through the filling valve (4, 4') of the container under the pressure of the water supply into said container (1).

Inventors: TER STEGE THIEME, TER STEGE, THIEME
Applicants: AIRSPRAY INT BV, AIRSPRAY INTERNATIONAL B.V.
Application year: 1986
Main classification: B65D83
IPC codes: B05B7, B05B9, B65D83