IL31781A - Aerosol-type dispensers - Google Patents

Description

IMPROVEMENTS IN AEROSOL-TYPE DISPENSERS Tills invention relates to an aerosol-type dispenser for spraying a product, generally a liquidj by means of a liquefied gaseous propellant which is designed to escape in the .gaseous phase, when the user actuates a valve-actuating means More precisely this invention in directed to an aerosol dispenser having separate charges or fillings, that is to say f the type in which the charge to be sprayed is contained in a container distinct from that containing the propellant charge, generally consisting of a liquefied gas under pressure; These aerosol dispensers are differentiated from those comprising a single container holding a single charge consisting of the agent to be dispensed and the propellan t which latter is partly in the gaseous phase above the liquid; Such dispensers require a rigid and strong container to hold the liquid and gaseous phase under pressure.

Other aerosol dispensers are known in which the liquid charge to be sprayed is contained in a flexible and extensible bog, like a bladder. This bag is accommodated in a rigid container filled by the at least partly gaseous propellant under pressure which is thus not brought, during storage, into direct contact with the agent to be dispensed, which )Offers numerous advantages; In these types of dispensers the pressure of the gas prevailing in the interior of the ooutainex* surrounding the flexible bag serves to compress this latter and to expel liquid from the bag as soon as the valve is opened. The emptying of the bag is thus effected by compression; This invention relates to dispensers wherein the two aforesaid charges i,ei the agent to be dispensed and tho propellant," bro separated and In which a flexible bag for storing the agent to be dispensed Is used in a novel combination; According to the invention, the aerosol dispenser for spraying a product, generally a liquid, housed in a first container by means of a gaseous propellant under pressure which is housed in a second container distinct from said first container, said dispenser comprising a valve means t a spraying nozzle of the Venturi type and an aspiration circuit, controlled by said valve means and joining said first container to said spraying nozzle, is characterised in that said first container for said product to be dispensed comprises a flexible bag which is housed in a protective caaing, and in that said dispenser is provided with apertures permitting . a free communication between the interior of said casing and said outer atmosphere, whereby the outer wall of said flexible bag is kept at atmospherio pressure.

The emptying of the flexible bag is thus caused by aspiration, due to the combination of said bag with an aspiration circuit connected to said Venturi nozzle and which is put under subatmospheric pressure when said valve means io actuated.

Furthermore, the fact that flexible bags are used in dispensers of the above type results, as will be explained hereinafter, in a number of advantages^ In one embodiment of the invention the flexible bag houses the propellant reservoir, while, in accordance with another embodiment it constitutes an annular envelope which surrounds the propellant reservoir over at least a part of its surfaced In this latter case the annular envelope formed by the flexible ha is preferably wour.u. in a spiral round the propellant reservoir.

Various means are provided by the invention for fixing the flexible bag in the dispenser. In particular it may be fluidtightly mounted on the body of the valve-moans and^: in one type of embodiment, about a dip tube ensuring the feed of the contents of the bag to a spray nozzlei In another embodiment the flexible bag is connected to tha valve*Qea∑i.G by a linking element -which is fluidtigh+ly connected to the said bag and serves the valva controlling the flow of the agent to be dispensed.

As the outer casing is provided with orifices communicating with the outer atmosphere, the valve means of the dispenser only hixs to ensure a double obturation, namely, that of the propellant flow path and that of the flowpath of the product to be dispensed. This permits considerable simplification in the construction and the manufacture of the -valve means· The invention further provides for combining the dispenser as defined with means permitting the ejection of the propellant in the gaseous pba3e whatever the orientation of the dispenser(e«.g. by using a propellant adsorbed on a solid charge) so that in particular this latter may be used head downwards.

The invention will now be described in greater* detail by way of example with reference to the accompanying drawings, wherein : Figure 1 is a view in elevation of a section taken in an axial plane through a first embodiment of the invention, lig 2 shows in the same manner a second embodimentI Figure 3 shows in like manner a third embodiment , Figure 4 is a view in part section of the upper portion of the dispenser, along the line IV-IV in fig; 3.

Figure 5 is a diagrammatic view of the connection used in the abovementioned dispenser.

Figures 6 and 7 are part views of the exterior showing the variant forms of the propellant draw-off tube of the above embodiment. 0 Figure 8 is a part view in axial section of another variant.

Figure 9 is the corresponding plan view after sectioning along the line IX-IX in Figi 8i Figure 10 is a view in part axial section of another variant.

Figure 11 is a section cn a larger scale of part of figure 10, and Figure 12 is the section XII-XII in Figi 11.

In the embodiment of the invention shown in fig; 1 the dispenser is intended for spraying an agent in the liquid phase. The dispenser comprises an outer protective casing 1 made of plastics material or metal, having the shape of a can, carrying a valve means 2. The valve means 2 comprises in known manner a cap 3 mounted on a rim 4 of the casing li The cap 3 carries, in its central portion, an annular body 5 which grips round an annular flexible gasfce* 6i There is fixed on the body 5, ©· g«' ¾y crimping, an inner reservoir 7 containing the propellant 8 under pressure, a considerable portion of which is in a liquefied state, A frustoconical ring 9 inserted between the reservoir 7 and the body 5 ensures the fixing of a high pressure gjasbett 11 provided for the propellant; There is slidably mounted along the axis of the valve means 2 a hollow rod 12 hereinafter termed a jet, which comprises an expanded portion 13 co-operating with the gcakx 6 to form a low pressure obturator for the agent and a second expanded portion 14 which co-operates with the gaslcerfc 11 to form a high pressure obturator.

The circuit for dispensing the agent comprises an annular chamber 15 accommodated in the body 5> fed by a dip tube 16 and which is connected, when the valve is opened, to an annular duct 17 extending as far as the neck of a nozzle 18 of the Venturi type, accommodated in a push-button 19i There is further provided a central duct 21 for the propellant connected to radial ducts 20 normally obturated by the gaske 11. The duct 21 opens into the rear portion of the nozzle 18.

The double valve thus formed of a type known per se, is combined with the fact that the agent to be dispensed is contained in a flexible fluidtight bag 22 accommodated in the casing li The flexible bag 22 is preferably of the thin-walled type and extremely flexible.

This bag can be made of one of the following products : (a) polyethylene, either extruded, blown directly in its final shape, or obtained by sealing a film or sheath into the proper form, if the product is an aqueous or water-alcohol liquid producti Polyethylene has excellent impermeability with respe t to water and alcohols; (b) unplasticized polyvinyl chloride or polyamide; if the product to be sprayed is a material in solution in a hydrocarbon, or contains fragrant substances, since these two materials have good impermeability with respect to hydrocarbons and odors; (o) thin metl aluminium foil, for instance, if the solution contains solvents that are very incompatible with respect to most plastic materials, as, for example, halogenated, ketone or benzene solvents; (d) compound or laminated materials, e.gi polyethylene- regenerated cellulose, polyethylene-aluminium, polyethylene- polyesters, etc.;, for special uses, such as when solvents are involved for which no single plastic material is suitable, or for very good impermeability. The very broad range of flexible material presently available on the market makes it possible to find satisfactory solutions for a very large number of problems; In the embodiment of figure 1, the bag 22 completely contains the inner reservoir 7· In fact the said bag 22 has along its line of opening a reinforcing ring 23 which is fluidtightly fixed, for instance by welding, to the annular body 5 of the valve means e The bag 22 is filled with the liquid to be sprayed 2 t the said filling being effected in such a way as to avoid the introduction of air by means of a device permitting, in a preferred manner, of introducing at the same time the propellant and the agent to be dispensed, into their respective containers; When the bag 22 is full, it occupies substantially the whole of the free volume of the outer casing 1 and the liquid to be sprayed is directly in contact with the reservoir 7· In the embodiment described the bag 22 is placed under stress by the weight of the liquid 24 which it contains and it is completely suspended from the ring 23 and for this reason the bottom of casing 1 can be omitted; Here the said bottom simply consists of a cross-piece 25 having large apertures 26 between its parts and allowing a free communication with the outer atmosphere.

Inside the "bag 22 extends the slightly flexible dip tube 16i The equipment of the dispenser is advant geously completed, in known manner, by a removable cap 27, protecting the push-button 19i When the push-button 19 is pressed, the rod 12 slides towards the reservoir 7 which permits the escape of the propellant towards the nozzle 18 and the corresponding suction ensures the advancement of the liquid 24 through the tube 16 in the chamber 15, the duct 17 and the nozzle 18 where it is sprayed. The direct contact between the liquid 24 and the propellant reservoir 7 makes it possible to avoid a violent cooling of this latter in the case of -papo'>longed use of the dispenser. As the bag 22 is emptied it diminishes' in volumei If it is made of elastic material it contracts, or else its walls gradually apply themselves one against the other.

If there is any danger of harmful interactions between liquid 24 and the reservoir 7 (for instance in the case of aqueous compositions and metal containers) there is preferably used a type of construction as in figsi 2 or 3, or a complete separation is provided between the liquid 24 and the wall of the reservoir 7i In the version in fi i 2 the bag 22a has no inherent shape; It only has a narrow outlet orifice provided with a ring 31 whose diameter permits it to be threaded round the dip tube lCi The ring 31 is then welded or bonded to this tube. When the bag 22a is placed in position in the casing 1, it is arranged round the reservoir 7 and surrounds it over a variable portion of its surface.

It will be noted that in this version the bottom 32 of the casing 1 is solid while the cap 3 has orifices 33 for the admission of air.

To avoid the orifice 34 of the dip tube being obturated during use by the wall of the bag 22; the said tube has perforation! 35 distributed over its length.

To utilise to the full the free space existing between the casing ! and the reservoir 7, the invention further provides (figs. 3 and 4) to use for the liquid 24 a flexible bag 22c constituting an annular envelope wound in a spiral round the reservoir 7 and the body 5« The bag 22c has, more precisely, an outer wall 36 ;-uid an inner wall 37 connected together along an annular seau 38i "Preferably these walls are forned from one sheet suitably folded and welded or bonded.

It can be seen in Pig. 4 that the bag 22c terminates in thinned portions 39a, 39b , which overlap one another· The connection between the bag 22c and the annular chamber 15 of the valve means 2, is ensured by means of a connecting member 41 (figi5 This latter has a collar 42 in which are provided radial ducts 43 and a tubular body 44. * ' he -connecting nectben? 41 is inserted inside the bag 22c in such a way that the inner wall 37 is wedged between the collar 42 and an inserted ring 45 threaded round the body 44· This latter is, furthermore, sunk in a duct provided for this purpose in the body 5 and which opens into the chamber 15 i Th" lower part of the bag 22c rests on- the bottom 32 of the casin 1.

In this embodiment the reservoir 7 has means therein permitting the ejection of the propellant in the gaseous phase in all positions of the dispenser. Por this purpose the connection between the body 5 and the reservoir 7 is ensured by an inserted core or plug 46 having a chamber 47 permitting the passage of the expanded portion 14. The chamber 47 is extended by a tube 48 whose length is substantially equal to half the height of the reservoir 7ί Similarl it is rovided that the level of fillin the atart and in the vertical position of the dispenser, at the level of the suction orifice of the tube 48· It is of course possible, if so desired, to effect a hot welding or bonding, or a high frequency or ultrasonic welding of the collar 42 on the wall 37 and with the assembly of components 41 , 45 and 5.

Because of the relationships of the length of tube 48 and the level of falling of the reservoir 7, it will be understood that in the upright position of the dispenser the propellant is always drawn off in the gaseous phased Even if the dispenser ia reversed and brought head downwards, the propellant 8 follows the walls of the reservoir 7 and the free orifice of the draw-off tube 48 always remains in the gaseous phase. As emptying proceeds the bag 22c flattens, and the walls 36 and 37 come to lie flat one · against the other. Even if the wall 36 were to be applied against the collar 42; the surface ducts 43 permit the passage of the liquid towards the tubular body 44 in such a way that continuity of functioning is ensured; It may however ibappen, if the user abruptly turns the casing 1 upside down, that some drops of the propellant in the liquid state which have not had time to flow along the walls will penetrate into the draw-off tube 48, which would deleterious!/ affect the functioning of the device.

To avoid this phenomenon, the i.nvention provides various means which are shown diagrammaticall in figsi 6 to 9. In a first variant (figi 6) the end of the draw-off tube 48 is closed by a partition 61 near which are provided rectangular slots 62 or circular slots 63 (fig. 7). Of course,, these orifices have to be at the height of the plane which separates the reservoir 7 into two equal volumes^ In another version (figs. 8 and 9), the end of the tube 48 is provided with two superimposed dis s 64, 65 maintained in spaced position by radial partitions 66; The double cap thus provided prevents drops of propellant trickling along the tube 48 and penetrating the inlet orifice of this tube! The sane applies to drops of liquid^ Another means of permitting the functioning of the dispenser in any position is shown diagranmatically in figs, 10 to 12· It consists of filling the reservoir 7 with a product, for instance a powdery or spongy material capable of adsorbing the propellant or again of fortiing a gel with it. guoh a means is preferably in accordance with those disclosed in the patent application Ser.K 30766/68 filed by the same Applicant on 26th September Ί 1968 and entitled "Push-button dispenser with separated1^ phases" In this case it is advantageously provided to 'equip the inner ring 51 , inserted between the body 5 and the reseryoir 7, with a screen 52 having a succession of windows 53 obturated by a base 54 noulded in one piece with the ring 51 · The width of the windows .53 is sufficiently small to prevent the passage towards the valve of solid particles contained in the reservoir 7.

It will be noted that the low-pressure obturator has a colls.r 55 acting as a support for the return spring 56 rnd having, on the side opposite the joint 6, a stop surface 57 capable of being supported on ribs 58 arranged radially in the chamber 151 These ribs restrict the descent of the rod 12, even when the user pushes too hardi The invention offers substantial advantages over known dispensers wherein the propellant and the charge are housed in separate containers; These dispensers nay be used in any position, head upwards or head downwards or laid horizontally. This is useful in the case of a large number of products such as paints, waxes, body, deodorants and so on.

It is also to be pointed out that the combination of a flexible bag for the product to be dispensed and of means permitting the operation of the dispenser head downwards, causes dispensers to be manufactured which can be used in any position, without risks of leaks, whereas the valve means comprises only a double obturating^ This fact corresponds to a substantial lowering of th manufacturing costs· Danger of corrosion of the propellant reservoir is eliminated even if this latter is made of metal and the product to be sprayed is corrosive with respect to metals (as in the case of aqueous or alcoholic solutions) .

The danger of degradation of the outer casing in contact with the liquid to be sprayed is also eliminated! Likewise, there is no problem with respect to the permeability of this casing to the product to be sprayed. Thus, the casing can be made of inexpensive and permeable plastic materials, such as polyethylene or polystyrene. It can even be made of metal, wood, or cardboard without any limitation as to material or shape, other than thai, the material be sufficiently strong and rigid to protect the bag; Also, the invention makes it possible to prevent the risks of degradation of the product to be apirzqred fl o' to oocrrfcaict with the air. Such degradation can, for instance, consist of the formation of a film on paint or glue or the spoiling of the fragrance of a perfumed product! Similarlyp the dangers of contamination by bacteria or the dangers of oxidation and degradation of food products in contact with the air can be prevented completely! The connection between the valve neans and the outer casing no longer has to be tight· Fastening by neans of tight cementation or welding can;, thereforej be replaced by screwing or by neans of catches, which are nore sinple to manufacture and assembled The invention is not of course restricted to the forms of embodiment described and variants may be made in these. Thus in the preceding examples, the propellant reservoir is shown in the centre along the axis of the dispenser, but of course it its possible to place it in an eccentric position - for instance on · one side of the flexible bag containing the product to be sprayed if it is desired that the general shape of the dispenser should not be that of a body of revolution but should, for instance, be flattened, such a form being easier to keep in a bagi The reservoir for the propellant nay be placed in the horizontal position OJP above or below the flexible bagi In any case, the connections between the flexible bag and the valve neans and also between the propellant reservoir and this latter nay be obtained by neans of tubes, possibly flexible tubes, of a suitable length; It is likewise understood that the invention is independent of the type of valve used. A valve nay be fitted on the dispenser in which the high pressure obturating means and the low pressure obturating neans are integrated in one no nting as shown diagranatically in the drawings^ It is also possible to produce a mechanical assembly of a high pressure obturating neans and a low pressure obturating means capable, before mounting, of acting independently of one another.

It is also possible, as a variant, to utilise two or more flexible bags each containing different products which it is desirable not to nix before use and which are only to be nixed when spraying takes place, by sinultaneous suction on the various

Claims (1)

1. WHAT IS CLAIMED IS I 1· An aerosol dispenser for spraying a liquid product contained in a first container*, by means of a propellent which is gazeous under normal pressure and which is contained in pressurised state in liquid state in a second container, distinct from the said first container* the said dispenser being equipped with a valve arrangement which controls - on the one hand - the flow of gazeous propellant* and — on the other hand - the flow of the product* from the said containers to a venturi-nozzle which is located in a spraying head which serves for actuating the valve arrangement* both the said container of the product and that of the propellant being fixed to the casing of the valve arrangement* characterised thereby that the container of the product is constituted by a tight and flexible bag (22, 22a or 22c which is collapsible or which is compressible by atmospheric pressure* from which the product ( 4) is sucked at the passage of gazeous propellant through the venturi nozzle into the latter and further thereby that there is provided a protective jacket (l) which embraces the bag and the container of propellant (7,)» wherein the valve arrangement (5, 6, 9 - 15) is set and which preferably is provided with openings (26* 33 respectively) which establish communication between the interior of the protection jacket and the open, the wall of the bag which is surrounded by an atmosphere of not more than normal pressure* collapsing to such an extent, or is being compressed by atmospheric pressure at the ratio of product being sucked from the bag, the bag haying a wall being impervious to the atmosphere, so that an exit o the product - in whatever position of. the dispenser -Is possible only via the venturi-no.zzle. 2· Dispenser, as claimed in Claim 1, characterised thereby that the container of propellant (7) is. provided with mechanical (¾7t 52) or chemical means which prevent the exit of liquid propellant (8), so that the venturi nozzle (18) whenever the valve is operated (5, 6, 9 - 15) - in whatever position of the dispenser - beside by the liquid product can be reached only by gazeous propellant. 3. Dispenser, as claimed in Claim 2, characterised thereby that the propellant (8 ) in the container thereof (7) is absorbed by a porous or powderous means so that there does not exist any free liquid in the propellant-container. 4. Dispenser, as claimed in Claim 3, characterised thereby that the inlet part (53) from the container of propellant (7) into the valve arrangement (21, 22) is protected by a sieve (52-5*0: which prevents the passage of solid particles emanating from the substance in which the propellant is absorbed or to which it is adsorbed. 5· Dispenser, as claimed In Claim 2, characterised thereby that the container of propellant (7) is provided with a dispensing tube (**8) the length of which is less than the height of the container of propellant which, originally had been filled to a level lower than the opening o the dispensing tube. 6. Dispenser, as claimed in Claim 5» characterised thereby that the opening (62, 63) of the dispensing tube (^8) is provided in a lateral wall thereof, the closing part of the tube being sealed by a wall (6l), 7· Dispenser, as claimed in Claim 5, characterised thereby that the openin (66) of the dispensing tube ( 8) is provided with a double cap (6¾, 65) preventing the entry of liquid flowing along the tube into said opening. 8. Dispenser, as claimed in Claim 1, characterised thereby that the flexible or compressible bag (22) contains the container of propellant. 9-· Dispenser, as claimed in Claim 1, characterised thereby that the flexible or compressible ba (22a) constitutes a cloak embracing the container of propellant (7) at least over part of its surface. 10. Dispenser, as claimed in Claim 9» characterised thereby that the flexible or compressible bag (22c) which forms a cloak extends around the container of propellant along a spiral line. 11. Dispenser as claimed in Claim 1, the valve casing there is provided a dip tube for conveyance of the product to be sprayed, characterised thereby that the flexible or compressible bag (22a) is fixed tightly around the dip tube. 12. Dispenser as claimed in Claim 1, characterised thereby that the protective jacket (l) is formed by a sleeve without bottom* 13· An aerosol dispenser substantially as hereinbefore described with reference tq and as illustrated in, the accompanying drawings*