IL28964A - Dispenser with separate propellant for products in fluent phase - Google Patents

Description

C O H E N Z E D E K & S P I S B A C H R EG D. PAT E NT AT TO R N EYS 24, LE VON IN SIR., P. O. B. 1169 T E L - A V I V P A T E N T S & D E S I G N S O R D I N A N C E 17171/67 SPECIFICATION DISPENSER WITH SEPARATE PROPELLANT FOR PRODUCTS IN FUJENT PHASE J. R. GEIGY S.A., a Swiss Soci^te* Auonyme, of 215» Schwarzwaldall£e , Basel, Switzerland, HEREBY DECLARE fhe nafure of fhis invenfion and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement : This invention relates to a push button dispenser for the distribution in fractions and in the atomised state of an active agent in a fluent phase (liquid or powdery product) by means of a propellant constituted by a compressed, preferably liquefied, gas, this propellant being contained in a reservoir which separates it completely from the fluent phase to be dispensed.

Dispensers of the above type are known already, serving in particular to form aerosol sprays, and in which the propellant reservoir is housed in an exterior container which contains the fluent phase to be distributed.

More specifically, the instant invention relates to improvements to dispensers of a known type wherein the propellant reservoir, situated inside the container containing the active agent, is carried by a mounting obturating this container. This mounting comprises a high-pressure obturator for the propellant reservoir and two low-pressure obturators controlling respectively the passage of the active agent from the container towards the atomisation nozzle of the push button and the passage of outside air towards the interior of the container. The tubular control stem of the push button which allows the circulation of the propellant and of the active agent towards the atomisation nozzle is arranged to slide in said mounting and controls the three aforesaid obturators.

The mounting and its attachments constitute a detachable sub-assembly carrying the propellant reservoir and which can be fitted on various containers. Such dispensers have enabled the range of use of appliances of the aerosol The improvements which form the subject matter of the present invention have the object of facilitating the industrial manufacture of dispensers of the type in question and of decreasing their cost price. They tend also to enable the assembly of the dispenser component on automatic machines and the filling of the dispenser by means of conventional filling machines.

Another object of the invention is to make a dispenser having good performance with regard to the fineness of the atomisation and the removal of droplets at the beginning or end of operation. The invention likewise has the object of obtaining a regular and complete emptying of the container containing the active agent, corresponding to an optimum output for the propellant.

In accordance with the invention, the dispenser is characterised in that the mounting comprises a central body and a cover, and in that the gasket of the high-pressure obturator is fitted into the body of this mounting.

This arrangement which enables the high-pressure valve to be integrated in the mounting produces important technical results, as will be seen.

In accordance with a preferred embodiment of the invention, the setting of the gasket of the high-pressure obturator is ensured by fastening this gasket between a-shoulder of the body of the mounting encircling an aperture for the passage of the tubular stem connected to the push button, and a sleeve force-fitted into a recess of this body.

In these circumstances, it can be advantageously be provided that the propellant reservoir is fitted This arrangement considerably facilitates the assembly, then the filling of the reservoir with propellant.

The gasket of the high-pressure obturator of the annular type, can be of the type which flexes under the action of a shoulder of the tubular stem, as well as of the fixed type, the tubular stem sliding through said gasket.

According to a preferred embodiment of the invention, the tubular stem has an axial duct for the passage of the propellant and an annular duct for the passage of the active agent. On operation of the push button, these two ducts communicate respectively through apertures with the propellant reservoir and with a recess fed with active agent to be dispensed.

In particular the tubular stem can advantageously be made in one piece and be fitted by its end opposite to the obturators in the head of the push button.

Other improvements contemplated by the instant invention relate to the connection of the high pressure gasket with the central body of the mounting and the fixing on this latter of the propellant reservoir.

According to one of these improvements, the high pressure obturator gasket is mounted in a recess of the body of the mounting, directed towards the propellant reservoir, the said gasket being fixed in the said recess by a faatoning - or tightening - ring - or sleeve.

This arrangement allows a remarkable simplification in structure and fitting up and increases the tightness of the assembly.

In a preferred embodiment, the fasterdiqgring of the high pressure gasket consists of a built up annular component, fixed in a recess or cavity of the body of the mounting and this ring is itself crimped between the body of the mounting and the neck of the propellant reservoir.

According to another embodiment* likewise interestin for its economy in components obtained, the high pressure gasket fastening ring forms one body with the neck of the propellant reservoir, which may be .either crimped on an annular roll held by the body of the mounting, or stuck or welded on the said body. The manner of fixing chosen depends on the nature of the wall (metal or plastics).

According to a still further improvement the push button tubular stem has on the outer surface a set of longitudinal ribs and the push button capping this stem has a socket in which the said stem is inserted and on the inner surface of which the said longitudinal ribs are supported in such a way as to constitute ducts for the passage of the active agent.

This construction facilitates the production of the push button.

Other features of the invention will appear ^further from the following description.

Specific embodiments of the invention will now be described by way of non limiting exampleswith reference to the accompanying drawings, in which : Fig. 1 is view in axial section of a mounting and its attachments in the rest position.

Fi 2 is a corres ondin view on a smaller Fig. is a view in axial section of a second embodiment at rest.

Fig. 5 is a similar view of the embodiment of fig. 4 during actuation.

Fig. 6 is a view in axial section of another embodiment at rest.

Fig. 7 is a similar view of the embodiment of fig. 6 during operation, and Fig. 8 to 10 are graphs relating to the operation.

Fig. 11 is a view in elevation, in axial section, of the upper part of a dispenser in accordance with another embodiment.

Fig. 12 is a section on a larger scale taken along the line XII-XII in fig. 11.

Fig. 13 is a view in elevation of a part of the push button tubular stem.

Fig. 14 is a diagrammatic view similar to Fig. 11 showing another embodiment, and Figs. 15, 16 and 17 are diagrams showing in axial section various connections between the propellant reservoir and the mounting.

Referring to fig. 1, there can be seen the mounting of a dispenser according to the invention which comprises a cover 1, for example of plastics material, to which is attached a body 2, these two members receiving mutual support on a shoulder 3 having a socket receiving an annular flexible gasket 4 which belongs at the sane time to the low pressure obturator provided for the active agent, and to the low air. (With "obturator" is meant throughout the instant specification and claims : valving means). The fastening of the components 1 and 2 can be ensured for example by ultrasonic welding.

In the cover 1 there is provided a central aperture 5 and in the body 2 there is an axial recess 6 both of which are traversed with a radial clearance by a tubular stem 7 connected to an actuating push button 8 containing an atomisation nozzle 9 of the venturi type which is fitted into a cavity 11 of the head of the push button 8. The recess 6 communicates through an aperture 12 with a widening-out section 13 provided at the bottom of the body 2.

According to one of the features of the invention, the aperture 12 is bordered by a projecting collar 14 on which there is supported an annular flexible gasket 15 belonging to the high-pressure obturator and which is crimped between this collar 14 and a sleeve 16 force fitted into the recess 6.

The stem 7, which is moulded in one piece, is provided for the passage of the propellant with an axial duct 17 limited by a conical head 18 , inserted in the aperture 12. Radial apertures 19 provided in the wall of the axial duct 17 are obturated in the' rest position of the stem by the flexible lip of the gasket 15 the central aperture of which is traversed by the head 18.

The stem 7 further comprises, around the duct 17, an annular duct 21 the wall 22 of which is separated by apertures 23 from a plug 24 arranged in the recess 6 beyond the gasket 4 relatively to the aperture 5. The edges The plug 24 is stressed by a spring 25 accommodated around the stem 7 and which rests at the same time on it and on the sleeve 16· This stressing is such that the flexible lip of the gasket which rests on a frusto-conical shoulder 26 of the plug 24 is curved as shown in Fig* 1 and takes counter support on an annular rib 3 of the cover 1. This ensures the tight closure of the recess 6 with regard to the aperture 5.

Opening into the recess 6 is a dip tube 29 which is force fitted in a duct 31 of the body 2 and which is intended for the passage of the active ¾gent. (With "active agent" is meant within the instant specification and claims the product, either in liquid or in powdery form, to be dispensed .

In this position of the stem 7, an airtight closure is likewise ensured between the aperture 5 which communicates with the outside atmosphere on account of the clearance provided for the sliding of the atomiser and the space inside the cover 1 which is brough into connexion with the face of the gasket 4 turned towards the annular projection $ by at least one radial drain 32.

In this same position of the stem 7, the lip of the gasket 15 is urged by the head IB of the stem towards the sleeve 16 obturating the apertures 19 so that a tight closure between the aperture 12 and the axial duct 17 is ensured.

In accordance with another feature of the invention, on the side opposite the body 2, the tube of the axial duct 17 is force-fitted as far as to come in abutment in a recess 34 of the push button 6, which communicates through a duct 35 with the convergent aperture 36 of the nozzle 9.

In this position there is formed, at the end of the annular duct 21, an annular chamber' 37 which communicates through a duct 33 with a second chamber 39 of the recess 11 into which open radial ducts 41 coming on the neck of the nozzle 9» to which divergent opening 4 forms a continuation.

According to a further feature of the invention, it is provided to fasten the propellant reservoir 43 on a collar 44 of the periphery of the body 2. Tightness is ensured in the example described by a set in gasket 45.

This gasket can also be cast in situ, or can again be left out if the body 2 is of sufficiently supple material (for example polyethylene) to allow a tight fitment on the neck of the reservoir 43.

In the case in which the propellant reservoir 43 is made of plastics material, its neck can be welded or stuck directly on to the body 2.

The autonomous sub-assembly thus formed has the feature of being capable of assembly by axial force-fitting and with a reduced number of welding operations, which latter can be carried out by known automatic machines.

The reservoir 43 having been placed in position, it is then possible to create a vacuum inside it, the axial duct 17 of the stem 7 allowing, when the atomiser is retracted, the creation of a vacuum in this reservoir and to fill it correlatively with liquefied propellant gas 46 by means of conventional conditioning machines. The subassembly is then ready to be mounted on a container 47 (fig. 2) containing the active agent 4$ to be dispensed.

For this purpose the cover 1 has a rim 49 which fits on to a recessed shoulder 51 of the container 47.

The assembly of these two components can be effected by ultrasonic welding. The shoulders 51 and 49 can be so dimensioned as to permit the detachable mounting of a cap 52 covering the push button S when not in use.

It will be understood that in the case of thrust in the direction F on the push button the stem 7 slides in the aperture 5 and into the recess 6 (fig. 3 ) . The shoulder formed by the wall of the stem 7 above the holes 19 makes the gasket 15 bend. The apertures 19 thus penetrate into the reservoir 43, while the gasket maintains tightness as explained above. The propellant in the gaseous state escapes into the duct 17, then passes through the duct 35 to the convergent opening 36 (arrows P) . The releases of the propellant through the nozzle 9 creates a vacuum in the chamber 39 which is transmitted through the duct 38 to the annular duct 21 and to the apertures 23 which have penetrated into the recess 6, the gasket 4 having bent under the pressure of the shoulders of the neck bordering these apertures 23 , closing tightly at the same time the communication betweea.the recess 6 and the outside. The vacuum is communicated through the recess 6 to the tube 29 which causes the suction of the active agent 43 , which passes into the recess 6 then through the annular duct 21 up to the radial duct 41 (arrows L) from where it is atomised in the nozzle 9 by the flow of propellant.

At the same time the vacuum created in the container 47 by the discharge of the active agent 4S cause the inlet of outside air, which passes between the aperture 5 and the stem 7 and, the gasket 4 being flexed, between the latter and the annular projection 28 and then penetrates into the drain 32 and from there into the gaseous volume of the container 47 (arrows A).

The dispenser, thus arranged with a simplified structure and the high-pressure obturator of which is integrated into the body 2, has a very safe operation.

Its weight is ^reduced and also its cost price and its assembly can be effected very quickly.

The embodiment shown in Figs. 4 and 5 is remarkable in that the high-pressure gasket 55 is here of the non-flexible tubular type and in that the stem 7 ends in a cylindrical nipple 56, at the end of which the head 18 is provided. A single aperture 57 can be provided at the inlet of the duct 17 At rest the aperture 57 is situated opposite the part of the gasket 55 which obturates it.

In this version the core or plug 24 is provided with an annular groove 8 into which the spring 25 penetrates. This allows the stroke of the stem 7 as well as the deflection of the spring 25 to be increased if necessary or to have a more compact assembly.

There is provided in the embodiment shown in Figs. 6 and 7 a thick annular gasket 60 for the high-pressure similar to the aforesaid gasket 55, but here the locking sleeve 59 of the gasket 60 is disposed towards the reservoir 43» this sleeve 59 being force-fitted in a 13 · This device enables the fitting of a gasket 60 of greater diameter than that of the recess, 6 which is favourable for the satisfactory firmness of the gasket.

It will be noted that in this version the duct 17 opens out into a chamber 62 of enlarged dimensions into which the convergent opening 36 of the nozzle 9 penetrates for reasons which will be explained further on.

The dispenser provided with a high-pressure gasket 15 of the bending type according to the first embodiment (figs. 1 to 3) and the dispensers with high-pressure gaskets 55 or 60 of the type with sliding stem according to the other embodiments (figs. to 7) have different dynamic characteristics which constitute specific technical effects for these dispensers permitting the choice between one or other of these embodiments as a function of the technical effect sought.

More precisely, and presuming that the active agent δ is a liquid, in the first embodiment, at the time of the opening of the obturators, the passage of the propellant begins before that of the liquid and the reverse phenomenon takes place on closure, as the curve in Fig. 8 shows, in which the rate of flow is plotted (for example in grams/second) along the D axis and the stroke of the stem 7 (for example in mm) along the H axis.

It will be observed therefore that the difference in depth to which the push button 8 is pushed by the used causes the efficiency of the system to v&ryj that is to say the relation between the uantit of ro ellant In fact the operations take place in the followin order : 1) Button depression of 0 to 0.3 ram - Nothing comes out. 2) Button depression of 0.3 to 0.6 mm - Only the propellant comes out up to its maximum rate of flow at a depression 3) Button depression of 0.6 to 1 mm - Only the propellant continues to come put (with a constant rate of flow of 120 g/s). 4) Button depression of 1 to 1.6 mm - The propellant is still coming out with its maximum rate of flow, and the product is sucked up with an increasing rate of flow according to the movement up to 1.6 mm (of 0 to 0.360 g/s).

) Beyond le6 mm the total rate of flow remains constant.

When the push-button is released, the sequence is reversed. This phenomenon has the advantage of completely expelling the liquid that remains in the nozzle. When pressure is again applied on the push button the atomisation is fine from the beginning and does not contain any droplets.

The only thing reverse to this advantage is the fact that it is necessary for user to press the push button doxvn completely, as otherwise the efficiency of the dispenser is lower than its maximum value, with the result that the propellant is exhausted more quickly than the liquid and the container 47 cannot be completely emptied.

In the second and third previous versions, the varied dynamic conditions can be obtained according to the positions of the high and low-pressure gaskets relatively to corresponding apertures of the stem 7, also taking into account the thickness of the high-pressure gaskets.

In particular it is possible to proceed in accordance with a first arrangement so that the passage of the propellant begins after the opening of the low pressure obturator. There is then for example the following sequence (fig. 9) : 1) Button depression of 0 to 1 mm - Nothing comes out. 2) Button depression of 1 to 1*6 mm - Opening of the liquid passage, . however nothing comes out. 3) Button depression of 1.6 to 1.7 mm - The liquid passage stays wide open but nothing comes out. 4) Button depression of 1.7 to 2 mm - The liquid passage is open and the gas passage opens progressively in order to bring about a maximum total rate of flow of ) Beyond 2 mm the maximum total rate of flew remains constant..

When the push button is released, the sequence is reversed. The atomisation stops as soon as the gas is cut off. The efficiency remains constant and the emptying of the container 47 containing the active agent is complete.

As in these arrangements the resistance in pressing down the push button $ is practically constant, the risk of operating the dispenser at reduced output This mode of operation is that which brings about the greatest economy of the propellant, on the other hand, as the liquid rises up until the last moment before the cutoff of the propellant, liquid is left in the circuit after the closure of the dispenser and this results in by the projection of droplets at the beginning of the next atomisation.

According to another mode of operation preferred by the invention for the high-pressure gaskets of the sliding type, it is provided to arrange the aperture of the passage of the propellant and liquid in such a way that the propellant starts to escape very shortly before the opening of the liquid circuit, in other words (fig. 10) that there is overlapping of the phases of opening of the circuit cf the propellant G (course h^h^) and of the liquid circuit L (course i^ ^) .

In these circumstances, the duct containing the liquid is completely cleared by the propellant at the end of the period of use and there is no risk of droplets at the time of the following atomisation.

Of course, in order to reduce the consumption of propellant, it is advantageous to reduce as much as possible the length of the course h-^.

According to another mode of operation, more preferable than the preceding one, the removal of droplets can be obtained and again reducing at the same time the consumption of propellant. To this end, it is · contemplated to ensure the opening of the propellant circuit slightly after that of the liquid circuit according to the graph in fig. 9, as far as two following conditions - arrangement of high-pressure gasket and in particular of the aperture 57 so that no appreciable loss in pressure is produced when the propellant passes through the duct 17 of the stem 7. This result is obtained by providing for the aperture 57 of the stem 7 a passage section considerably greater than that of the construction of the nozzle 9 (for example 2 to 8 times greater) . - providing a sufficient volume of gas between the high- pressure obturator and the nozzle 9, this result being obtained by the existence of the chamber 62 in the version in figs. 6 and 7» More precisely this chamber should have such a .capacity that the time for outlet of the gas propellant under pressure contained in the duct 17 and the chamber 62 is at least equal to the time necessary for the total of delays corresponding respectively to the passage of the tubular stem from the closed position of the propellant to that of the liquid and to the cleaning of the nozzle, the latter period being very short, for example about l/lOth of a second.

Of course, with the high-pressure obturator of the sliding type, the action is always such that the aperture 57 of the atom 7 is obturated by the joint at rest, so as to prevent the passage of the liquid contained in the' recess 6 inside the canal 17.

In the improved embodiment of fig. 11, the gasket 15 of the high-pressure obturator is mounted in a recess 6 of the body 2. This recess is turned towards the propellant reservoir 43, which is for example made of a metal 3 such as aluminium. The gasket 15 is held in the recess 65 by an annular fastening member 66 hereinafter referred to as fastening ring which consists of an independent component in the shape of a truncated cone and having a central orifice 67 in which the conical head 1& of the tubular stem 7 penetrates.

The fastening ring 66 which ensures the fixing of the gasket 15 is forcibly inserted in a cylindrical cavity 70 provided inside the body 2 and is itself crimped between an annular widening 68 provided on the periphery of this body and the neck 69 of the reservoir 43. The end portion of the reservoir 43 is bent |n such a way as to fit tightly both the contour of the annular projection 68 and a swelling 71 of the same diameter as the ring 66, which is made of a material sufficiently flexible to ensure, due to the crimping of the neck 69 , a tight connection between the propellant reservoir 43 and the body of the mounting.

Furthermore^ it is also possible to choose the ring 66, in a known way, of a material having a suitable tighteness to the propellant in the reservoir 43. In this way leakages by permeation through the material of the body 2 are avoided.

It can be seen that the assembly thus described is speedy and easy and that the components such as the body 2 and the fastening ring 66 can easily be made by plastics moulding.

According to another improvement the stem 7 has, on its outer surface, a set of longitudinal ribs 72 (fig. 12). On its side, the push-button 8 which caps the stem 7, has at its base two co-axial sockets : an outer socket 73 in inner socket 74 which caps the tapered end 75 of the duct 17 reserved for the propellant. The extent to -which the sockets 73 and 74 can go on the stem 7 is restricted by an annular proj ecting edge 76 provided at the base of the ribs 72.

Once the fixing-on is effected the ribs 7^ delimit with the socket 73 i ducts 77 reserved for the circulation of the active agent to be atomised.

It will be noted that by virtue of this construction, production by moulding of the stem 7 is remarkably facilitated.

According to another improvement, the low pressure obturator has an annular collar 78 held by the stem 7. The collar 78 has a frusto-conical outer surface 79 cooperating with the gasket 4. The surface of this collar 78 , opposite the gasket 4, is straight and acts as a support for the antagonistic spring 25, while also acting as a mobile stop for the push-button assembly. In fact there are provided inside the recess 6 fixed radial stops 82. If the pushbutton 8 sinks in too deeply, contact with the surface 81 and stops 8"2 restricts its stroke.

In the embodiment shown in Fig. 14 the fastening ring provided for the gasket 15, forms one body with the neck 33 of the propellant reservoir 43 » which here consists of a metal receptacle drawn on by the neck. The fitted-on base 4 of this receptacle is fixed by annular welding.

This embodiment is simpler than that consisting of welding the neck on the body. To fix the body 2 of the mounting, the neck is gripped by a ring 8 on an annular swelling 86 provided along the free edge of the body 2. It will be noted that in this embodiment the assembly constituded b the mountin and the reservoir com rises onl three com onent Several modifications may be provided to ensure the fastoning of the neck of the reservoir 43 on the body 2.

Thus in the version shown in Fig, 15t the body 2 is solid, the chamber 70 being suppressed. The neck 87 of the reservoir 43 is bent back on itself in such a way as to constitute a double crimping ring 88 located in an annular groove 89 of the body 2. Adjacent to the double ring 88 is a dome 91 which penetrates a cavity 92 of the body 2 and grips, by its end, the gasket 15.

An inverted arrangement is adopted in Fig. 16, where the gasket 15 is crimped by an inner double ring 94 formed by the neck 95 of the reservoir 43. The outer surface of the double ring 9 fits the annular proj ection 90 of the body 2 and the fixing is completed by crimping the and portion in the groove 89 of the said body.

In- he version shown in Fig. 17 the neck 95 cf the reservoir 43 is made of a plastic material tight to the propellant, the body of this reservoir and its two parts being welded together along their common socketting surface 96. The shape of the neck 95 is, further, similar to that of the fastening ring 66 in the enbodimont of fig. lle In particular it has a cylindrical shoulder 9 forced into the cavity 70 of the body 2. The stopping is effected by a rim 97 along which the components 95 and 2 are welded together, for instance by ultrasonic welding. The utilization of a reservoir of plastics material solves the problem of corrosion of the reservoir 43 either by the propellant or by the active agent contained in the outer receptacle.

Of course this invention is not restricted to the various embodiments described, and numerous modifications may be made to these within the sco e of the a ended claims.

Claims (1)

1. 289641 WHAT IS CLAIMED ISt 1· A push-button aerosol dispenser for fractionated spraying of a fluid product by means of a propellant gas accomodated under pressure in a reservoir surrounded by a container holding the product to be dispensed and carried by a mounting to which the said container is connected, the said mounting containing high pressure obturation means for controlling the passage of propellant from the reservoir, and low pressure obturation means controlling the passage of the product to be dispensed from the container, towards a venturi-ty e spray nozzle housed in a push button, a tubular stem connected to the push-button and permitting the flow of the propellant and of the product to be dispensed towards the spray nozzle, said stem bein mounted for axial displacement in the said mounting and controlling the aforesaid obturating means, characterized in that the mounting comprises a central body (2) having a central bore (6) therethrough and opening into a recess (13) oh that side of said body facing said reservoir, an annular shoulder protruding into said bore, the opening of said recess in the base of said body having a diameter larger than the opening of said bore (12,67) in said shoulder, said tubular stem (7) extending through said bore and being adapted for axial displacement relative to said body (2), that said mounting further comprises holding means for engaging said propellant reservoir at a peripheral zone of said central body outside said recess; and that said high pressure obturating means comprise an annular gasket (l5) and fastening means (16,66) holding said gasket in position in said bore against said shoulder in the latter* 2. A dispenser as claimed in Claim 1, wherein said annular gasket is located on the shoulder of said bore 28964/1 ' means is a sleeve member force-fitted into said bore on top of said gasket (reads on Figures 1-5)· 3. A dispenser as claimed in Claim 1, wherein said annular gasket is located on the shoulder in said bore facing said recess, and said fastening means is a separate ring member Inserted in said recess to hold said gasket against said shoulder (reads on Figures 6, 7 and 11)· A dispenser as claimed in claim 3» wherein said fastening means is a wall portion of said propellant reservoir projecting inwardly and upwardly into said recess from the reservoir wall portion which is engaged in said peripheral zone of said body outside said recess (reads on Figures 1* 17). 5· A dispenser as claimed in Claim 3, wherein said fastening means comprise a radial groove in the wall of said bore, Into which groove said annular gasket is inserted, and further comprise a wall portion of said propellant reservoir projecting Inwardly and upwardly into said recess from the portion of the reservoir which is engaged in said peripheral zone of said body outside said recess, said reservoir wall portion projecting into said recess being in contact with at least a central annular zone of said annular gasket on the side thereof facing toward said reservoir (reads on Figure 1 6. A dispenser as claimed in any of the preceding clai characterized in that the holding means for engaging the propellant reservoir are located on the outer periphery of the body of the mounting. 7· A dispenser as claimed in claim 6, characterized in that the propellant reservoir is crimped by its neck on a collar of the body of the mounting* 8. A dispenser as claimed in any of the preceding duct for the passage of* the propellant and annular duct means for the passage of the product, said axial duct and annular duct means opening, at the ends thereof toward said body, in different portions of said tubular stem. 9· A dispenser as claimed in claim 8, characterized in that the axial duct of the tubular stem opens with its outward end in a channel in the push-button connected with the convergent portion of the spray nozzle, and that the annular duct means open with their outward end into an annular chamber in the push button connected to the neck of the spray nozzle* 10. A dispenser as claimed in any of the preceding claims, characterized in that the tubular stem has a single-piece unit and that it is ensleeved in the push-button at its end opposite that engaging the obturator means in the push-button. 11. A dispenser as claimed in Claim 8, characterized in that said mounting further comprises a cover for said product container, which cover bears on its inner side the central body of the mounting, said cover having a central aperture registering with said bore in said central body, through which aperture said tubular stem extends to the outside of said cover, and in that said low pressure obturator means comprise a single flexible gasket mounted between said central, body and said cover, and that said tubular member is provided with a plug-like enlargement in a portion of said stem intermediate the opening of said axial duct and said annular duct means of said stem, said enlargement engaging said flexible gasket of said low pressure obturating means, when in non-dispensing position, and concurrently thereof urging said gasket into contact with an annular ridge provided on the inside of said cover about said a erture therein 28 6 I thereby preventing air from the outside to pass by said gasket into said product container and product from the latter to pass by said gasket into said annular duct means r> of said stem. 12· A dispenser as claimed in claim 11, characterized in that the tubular stem comprises a shoulder situated on the side of the opening of the annula duct means opposite to the plug-like enlargement of the low pressure obturators, the said shoulder ensuring the deflection of the gasket away from said annular ridge when in the dispersing position* 13· A dispenser as claimed in claim S, characterized in that said tubular stem is urged toward the non-dispensing position by spring means which are fitted in the portion of the bore of said central body between the plug-like enlargement of said stem, and fastening means for the high pressure gasket, or the shoulder in said bore. 1¾ A dispenser as claimed in claim 13 wherein said tubular stoin is provided with a protruding head at its free end, and wherein the axial duct for the flow of propellant in said tubular stem has an aperture in the portion of said stem engaged by said annular high pressure gasket, said aperture being obturated in non-dispensing position by said annular gasket; said spring means urging said stem head into engagement with the inner lip of said annular gasket, when in non-dispensing position. 15· A dispenser as claimed in claim 1¾ characterized in that the annular gasket of the high pressure obturating means is flexible and in that its free lip is seated in an annular recess of the said tubular stem adjacent to the said protruding head and the aperture of said axial duct in said 28964/1 l6* A dispenser as claimed in claim l characterized in that the annular gasket of the high pressure obturating means is rigid and in that a portion of said tubular stem adjacent the said protruding head is displaceably engaged by the last-mentioned gasket, the aperture of said axial duct being located in said stem portion* 17· A dispenser as claimed in any of the precedin claims characterized in that the high and low pressure obturating : moans are so arranged relative to one anot er that the One of these means opens before the other when said tubular stem is displaced from non-dispensing to dispensing position* 18* A dispenser as claimed in claim 17* characterized in that the high and low pressure obturating means are so arranged relative to each other that the low pressure obturating means is oponed before tho high pressure obturating means* If?, A dispenser as claimed in claim 18 characterized in that the high and low pressure obturating means are so arranged that the high pressure obturating means are opened by the displacement of the tubular stem toward dispensing position before the low pressure obturating means* and that the opening times of the high and low pressure obturating means overlap. 20. A dispenser as claimed in claim 9* characterized in that the aperture of said axial duct provided in the tubular stem at the end of said duct toward said body has a substantially larger cross sectional area than has the neck of the spray nozzle* 21. A dispenser as claimed in claim 9, characterized in that a chamber is provided in the push button between the outward opening of the axial duct for the propellant in the tubular stem and the convergent portion of the spray nozzle. 22, A dispenser as claimed in claim 21 , characterized in that the volume of the chamber is such that the dis charge time of the gaseous propellant which it contains, from the moment of shut-off of the high pressure obturating means, is at least equal to the sum o the time required for the. tubular stem t6 pass from the propellant shut-off position to the product shut-off position and time required for clearing product from the nozzle. 23. A dispenser as claimed in claim 3, characterized In that the said ring member is of substantially frusto-conical shape and is crimped with its wider rim portion betvieen the central body of the mounting and the neck of the propellant reservoir. Zh, A dispenser as claimed in claims h or 5* Characterized in that said wall portion of the propellant reservoir projecting into said recess and which engages the high pressure gasket is crimped with a portion outside said recess about an annular bead of the central body of the mounting. 25, A dispenser as claimed in claim 2¾» characterized in that the propellant reservoir consists of a metal, receptacle drawn on by the neck. 26., A dispenser as claimed in claim 24, characterized in that the neck of the propellant reservoir farmed by the projecting wall portion of the latter is of moulded material 28964/1 and is welded to the material of the main wall of the reservoir the latter wall being likewise formed of moulded material * . L · .27. A push-button dispenser as claimed in arty of the preceding claims wherein the tubular stem has on its outer surface a set of longitudinal ribs and the push-button which caps the stem has a socket in which Is inserted the said stem and on the inner surface of which the said longitudinal ribs are supported in such a way as to form annular ducts for the passage of the product, 28. A dispenser as claimed in claim 27» characterized in that the push-button has a second socket in which penetrates the end of the axial duct which is provided in said tubular stem for the passage of propellant. Attorneys or Applicants