Abstract:
A fluid dispenser including: an entraining gas reservoir ( 10 ) provided with an actuator ( 12 ′) suitable for pressurizing the gas contained in the reservoir; a fluid reservoir ( 3 ); and a dispensing orifice ( 21 ) serving to pass a mixture made up of entraining gas and of fluid; the fluid reservoir ( 3 ) being separated from the gas reservoir ( 10 ) by a partition ( 31″; 31 ″′). The partition is permeable to the gas and impermeable to the fluid, so that the pressurized gas penetrates into the fluid reservoir ( 3 ) through the partition, and entrains the fluid with it towards the dispensing orifice. The fluid is urged towards the dispensing orifice by thrust mechanism ( 32″, 32 ″′) so that fluid is always present at the dispensing orifice.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of pending U.S. provisional patent application Serial No. 60/382,048, filed May 22, 2002, and priority under 35 U.S.C. §119(a)-(d) of French patent application No. FR-02.03923, filed Mar. 26, 2002. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a fluid dispenser comprising an entraining gas reservoir provided with actuating means suitable for pressurizing the gas contained in the reservoir, a fluid reservoir, and a dispensing orifice serving to pass a mixture made up of entraining gas and of fluid. The entraining gas reservoir thus serves as an air flush to entrain the contents of the fluid reservoir towards the dispensing orifice so as to be dispensed there in the form of a two-phase gas/liquid or gas/powder mixture. 
     BACKGROUND OF THE INVENTION 
     Numerous fluid dispensers of this type already exist, in particular in the fields of perfumes, of cosmetics, or else and especially of pharmaceuticals. Very often, the fluid is stored in the same reservoir as the entraining gas. Sometimes, the fluid and the entraining gas are stored in separate reservoirs. It is then necessary for the entraining gas to be able to take away some or all of the contents of the fluid reservoir. 
     In the prior art, FR-2 038 476 describes a powder dispenser comprising a gas (air) reservoir having the shape of a bellows on which is mounted a cylindrical duct. The dispenser further comprises an end piece designed to be mounted on the free end of the duct. This end piece defines a powder reservoir sealed with a partition made of air permeable and powder impermeable porous material. The end piece also forms a dispensing orifice sealable with a cap. When the bellows is squeezed, air is pressurized and expelled through the partition so as to enter the powder reservoir, thus creating turbulences in the reservoir allowing the powder and air mixing to be expelled through the dispensing orifice. 
     The partition makes it possible not only to retain the fluid inside the fluid reservoir, but also to disperse the flow of gas coming from the entraining gas reservoir. The fluid is thus entrained better towards the dispensing orifice. The partition acts as a screen, grating, or lattice defining holes in which the fluid builds up so that the flow of pressurized gas passes through the holes and entrains the fluid with it. A grating, screen, or lattice structure is suitable for a fluid in powder form, while a porous structure is more suitable for a fluid in liquid form. 
     An object of the present invention is precisely to facilitate entraining of the fluid by the flow of entraining gas. 
     SUMMARY OF THE INVENTION 
     To this end, the present invention proposes a fluid dispenser comprising: 
     an entraining gas reservoir provided with actuating means suitable for pressurizing the gas contained in the reservoir; 
     a fluid reservoir; and 
     a dispensing orifice serving to pass a mixture made up of entraining gas and of fluid; 
     the fluid reservoir being separated from the gas reservoir by a partition, said partition being permeable to the gas and impermeable to the fluid, so that the pressurized gas penetrates into the fluid reservoir through the partition, and entrains the fluid with it towards the dispensing orifice, characterized in that the fluid is urged towards the dispensing orifice by thrust means so that fluid is always present at the dispensing orifice. 
     In an embodiment of the invention, the partition of the fluid reservoir is situated in a constriction formed by the entraining gas reservoir. For example, the gas reservoir comprises a body and a neck, the neck defining an opening that communicates with the inside of the body via a duct, the partition of the fluid reservoir being disposed in said duct at least in part. This is an embodiment that is very practical. Another feature of the invention is that an end-piece is in leaktight engagement with the neck of the gas reservoir, said end-piece forming the dispensing orifice. Advantageously, the fluid reservoir is formed in part by said end-piece. 
     In another embodiment, the fluid reservoir has a body in engagement with the end-piece, said body forming said partition. Advantageously, the end-piece forms a socket that is open towards the gas reservoir and that is closed in part at the dispensing orifice, the fluid reservoir forming a body engaged in said socket. 
     Another practical feature is that the fluid reservoir has a first end at which the dispensing orifice is formed, and a second end, said second end being impermeable to the fluid and to the gas. Advantageously, the body of the fluid reservoir comprises a tubular segment forming said partition, said tubular section being in engagement in the end-piece, said segment defining a first end adjacent to the dispensing orifice and a second end closed off by a closure member that is impermeable to the gas. 
     It is thus possible to obtain dispensing that is more reliable and more uniform, since the entraining gas is constrained to pass through the dispensing orifice, which is always fed with fluid. According to an embodiment, the fluid reservoir comprises a movable wall in a direction corresponding to a decreasing of the reservoir volume. Advantageously, the partition is mounted to move relative to and advantageously towards the dispensing orifice. Preferably, the partition is urged resiliently in the direction in which the internal volume of the fluid reservoir decreases. Advantageously, the partition forms a part of the movable wall. In a practical embodiment, the partition is mounted on a scraper piston which is slidably engaged in a cylinder. In a variant, the partition is mounted on a prestressed resilient membrane organized to return towards a rest position. 
     According to another embodiment, the wall is movable by the pressurized gas flow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described more fully below with reference to the accompanying drawings which give various embodiments of the invention by way of non-limiting example. 
     In the figures: 
     FIGS. 1 and 2 are section views seen respectively from above and in profile through a first embodiment of a fluid dispenser of the invention; 
     FIGS. 3 and 4 are views respectively similar to FIGS. 1 and 2 for a second embodiment of a fluid dispenser of the invention; 
     FIG. 5 is a view in cut-away perspective of a third embodiment of a dispenser of the invention; and 
     FIGS. 6,  7  and  8  are views in section respectively through fourth, fifth and sixth embodiments of a dispenser of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the embodiments used to illustrate the present invention, the fluid dispenser comprises an entraining gas reservoir  10  formed by a receptacle  1  which is shown in FIGS. 1 to  4  in the form of a small flask or bottle that is substantially flat and that defines two substantially plane opposite faces  12  and  13  that are interconnected via a substantially circular peripheral edge  11 . The flask  1  is further provided with a neck  15  defining an internal duct  16  via which the reservoir  10  communicates with the outside. The neck  15  is provided with an annular top edge  150  and with a recessed inside wall  151 . The reservoir  10  serves to contain a gas, e.g. air. However, it is possible to imagine other types of gas as a function of the fluid that is to be dispensed. 
     This particular configuration of the reservoir  10  based on a flask  1  is not the only possible configuration: other shapes are possible for the entraining gas reservoir  10 , as shown in FIGS. 5 to  8  which show a reservoir in the form of a squeezable bulb. 
     In FIGS. 1 to  4 , one or preferably two plane faces  12  and  13  are substantially elastically deformable so that they can be brought together by pressing on them with two fingers, for example, so as to reduce the volume of the reservoir  10 . Thus, the gas contained inside is pressurized, thereby causing it to be delivered through the duct  1  which forms a constriction, thereby accelerating the gas inside. The two arrows referenced P show the directions of the force to be applied to the actuating walls  12  and  13  of the reservoir  10 . Naturally, it is possible to imagine other actuating means for reducing the volume of the reservoir  10 , such as, for example, a piston mounted to move inside a cylinder forming the reservoir. 
     In all of the embodiments, the entraining gas is associated with a dispensing end-piece  2 ,  2 ′,  2 ″ which is mounted in the neck  15  of the flask  1 . More precisely, the dispensing end-piece forms a fixing sleeve  24  which is engaged in leaktight manner in the neck  15 . To enable the end-piece to be held properly, the sleeve  24  forms a projecting profile or fixing bead  241  serving to come to be received in the recess  151  formed in the inside wall of the neck  15 . Above its sleeve  24 , the end-piece forms an abutment collar  23  which projects radially inwards and which comes into abutting contact against the top end  150  of the neck  15 . Above this collar  23 , the end-piece  2  forms a drum  22 ,  22 ′,  22 ″,  22 ″′ whose free end is closed off in part by a dispensing front end wall  20  provided with a through dispensing orifice  21 . It is also possible to have a plurality of dispensing orifices  21 . The dispensing end-piece internally forms a socket  25 ,  25 ′ which extends inside the sleeve  24 , inside the collar  23  and inside the drum. The socket  25  is wide open at the free end of the sleeve  24  and is closed off in part by the dispensing front end wall  20  provided with the orifice  21 . 
     The dispenser includes a fluid reservoir  3  containing a fluid in liquid or in powder form. In FIGS. 1 to  4 , the fluid reservoir  3  is formed by a tube  31  engaged in the socket  25 , closed off at one of its ends by an end wall  32  or by a stopper  32 ′ and closed off in part at its other end by the dispensing front end wall  20  that is provided with the dispensing orifice  21 . It is thus possible to say that the fluid reservoir is constituted mainly by the tube  31  closed off at its end wall and closed off by the dispensing front end wall  20  of the end-piece  2 . In this example, the reservoir  3  is tubular in shape due to the shape of the tube  31 , but naturally it is possible to imagine other shapes for the reservoir. However, it is advantageous for the reservoir  3  to be tubular in shape, at least so as to be fitted into the socket  25 . In addition, the tubular shape of the reservoir  3  makes it possible to create a cylindrical annular space  16  inside the neck  15 . It is generally advantageous for the reservoir  3  to extend inside the neck  15 , preferably to inside the reservoir  10 , as can be seen in the various FIGS. 1 to  4 . The annular space  16  forms an annular constriction inside which the pressurized gas coming from the reservoir  10  is accelerated very considerably. 
     The end wall  32  shown in FIGS. 1 and 2 may be formed integrally with the tube  31  and of the same material as the material thereof. In the embodiment shown in FIGS. 3 and 4, a separate stopper  32 ′ is mounted on the end of a tube  31  which then has no end wall of its own. 
     At its tube  31  and/or at its end wall  32 , the reservoir  3  forms a partition that is permeable to the gas from the reservoir  10  and impermeable to the fluid contained in the reservoir  3 . Thus, the fluid in liquid or in powder form stored inside the reservoir  3  cannot permeate into the reservoir  10  whereas the gas contained in the reservoir  10  can be driven through the porous or permeable partition of the reservoir  3  into the reservoir  3  so that it is then sprayed therefrom in two-phase manner. In the embodiment shown in FIGS. 1 and 2, the pressurized gas coming from the reservoir  10  can penetrate into the reservoir  3  at the tube  31  and also at the end wall  32 . In the variant shown in FIGS. 3 and 4, the separate stopper  32 ′ is entirely impermeable to gas so that the gas from the reservoir  10  is constrained to penetrate into the reservoir  3 ′ via the partition  31  which is mostly and preferably totally disposed inside the neck  15 . Thus, all of the pressurized gas if forced to go into the annular space  16  where it is accelerated considerably. In this way, the gas penetrates into the reservoir  3  at proper pressure or power. 
     FIG. 5 shows a dispenser having a receptacle  1  that is substantially in the form of a bulb that is deformable at its wall  12 . This receptacle internally forms a gas reservoir  10 . The receptacle forms a wide neck  15  which defines a large opening. An end-piece  2 ′ whose overall design is analogous to the design used in the preceding embodiments is engaged in the neck  15  via its sleeve  24 , and it rests on the neck via its collar  23 . This end-piece  2 ′ also forms a dispensing orifice  21  at its front wall  20 . This wall  20  is connected to the collar  23  via a drum  22 ′ that is frustoconical in part. The end-piece  2 ′ forms an internal socket  25 ′. A partition  31 ′ that is impermeable to the fluid (liquid or powder) and that is permeable to the gas is in engagement inside the socket, e.g. at a snap-fastening recess  220 . This partition  31 ′ subdivides the socket into two compartments, a first of which forms the fluid reservoir  3 , and the second of which is part of the gas reservoir  10 . This partition  31 ′ thus forms a body which extends transversely in the socket  25 ′, and which advantageously serves as a support for the fluid. 
     In this third embodiment, the end-piece forms an internal socket that is of relatively large diameter or cross-sectional area. The partition  31 ′, which may advantageously be in the form merely of a porous plate, extends perpendicularly to the direction of the flow of pressurized gas. Thus, the gas goes more directly through the partition, and thus does not encounter much head loss or much resistance. The speed of the gas beyond the partition in the reservoir  3  is thus more than sufficient to entrain the fluid towards the orifice  21 , assisted in this by the frustoconical shape of the drum  22 ′, which directs and concentrates the two-phase flow towards the orifice. 
     The embodiments represented in FIGS. 1 to  5  do not integrate the spirit of the invention, which will be explained in reference to FIGS. 6 to  8 . However, these embodiments comprise advantageous features able to be implemented with the invention. 
     FIG. 7 shows a fourth embodiment of the invention. The receptacle forming the reservoir  10  may be of a design analogous to or identical to the designs of FIGS. 5 and 6, i.e. in the form of a squeezable bulb. This reservoir  10  also forms a neck  15  in which a dispensing end-piece  2 ″ is engaged. This end-piece also forms a sleeve  24  engaged in the neck  15 , a radial collar  23  which rests on the top end of the neck  15 , a substantially cylindrical drum  22 ″, a front end wall  20  and a dispensing orifice  21 . In this example, the drum  22 ″ and the front end wall  20  are separate from the remainder of the end-piece  22 ″ formed by the sleeve  24  and the collar  23 . However, it is possible to imagine a variant embodiment in which the end-piece  2 ″ is made in one piece, as it is in the preceding embodiments. In this example, the drum  22 ″ and the front end wall  20  are thus made in the form of a cup whose end-wall is provided with a through hole at the dispensing orifice  21 . The cup is connected to the remainder of the end-piece  2 ″ by the free end edge of the drum  22 ″ being fitted around a fixing bushing  220  formed substantially in alignment with the sleeve  24 . The edge of the drum comes into abutting contact against the radial collar  23 . 
     In this embodiment, the dispensing end-piece  2 ″ is further provided with an internal radial flange  26  which projects inwards. This radial flange  26  serves as an abutment member for a spring  33 . The spring  33  serves to urge a follower piston or scraper piston  32 ″that is engaged inside the drum  22 ″. The scraper-piston  32 ″ may be made of a material that is permeable to the entraining gas and impermeable to the fluid. However, in the embodiment shown in FIG. 7, the scraper-piston  32 ′ may also be impermeable to the entraining gas but serve as a support for a partition  31 ″, which is permeable to the entraining gas and impermeable to the fluid. The entraining gas driven out of the reservoir  10  when said reservoir is squeezed is thus constrained to go through the partition  31 ″ to reach the inside of the fluid reservoir  3 . The fluid reservoir  3  is thus formed by the drum  22 ′, by the front end-wall  20  provided with its through orifice  21 , and by the scraper piston  32 ″ which supports the partition  31 ″. Since the scraper piston  32 ″ is urged resiliently by the spring  33 , the fluid inside the reservoir  3  is thus also urged towards the dispensing orifice  21 . It is thus guaranteed that fluid is always present at the dispensing orifice  21 , which is preferable in order to guarantee that dispensing beyond the orifice  21  is of good quality. In this example, the piston  32 ″ with its partition  31 ″ is moved towards the dispensing orifice  21 . However, it is possible to imagine variant embodiments in which the piston acts in some other direction, e.g. a transverse direction, but while nevertheless ensuring that the dispensing orifice  21  is continuously fed with fluid. The object of the piston  32 ″, and more generally of a moveable wall, is to guarantee that fluid is present at the dispensing orifice  21 . Naturally, this may be achieved by other means. 
     Reference is made finally to FIG. 8, which shows the fifth embodiment which is merely a variant of the embodiment shown in FIG.  7 . The entraining gas reservoir  10  may be strictly identical, i.e. in the form of a bulb. A dispensing end-piece  2 ″′ has a general configuration that is substantially identical to that of the end-piece  2 ″ of FIG.  7 . The end-piece  2 ″′ comprises a sleeve  24  engaged in the neck  15  of the reservoir, a radial collar  23  in abutment against the top end of the neck  15 , a drum  22 ″′, and a front end wall  20  provided with a dispensing orifice  21 . In this example, the dispensing end-piece  2 ″′ is made in one piece. 
     As in the embodiment shown in FIG. 7, the fluid stored in the reservoir  3  is also urged towards the dispensing orifice  21  so as to guarantee a permanent continuous feed. In this example, to guarantee such a permanent continuous feed, an elastically-deformable membrane  32 ″′ is provided that constitutes a moveable wall element of the fluid reservoir  3 . This membrane  32 ″′ is held around its periphery by means of a holding ring  26 ′ engaged in the drum  22 ″′. More precisely, the outer peripheral edge of the membrane  32 ″′ is wedged by the ring  26 ′ against the front end wall  20 . The membrane  32 ′ may be made of a material that is permeable to the entraining gas and impermeable to the fluid, but preferably the membrane  32 ″ serves as a support for a partition  31 ″′ which may advantageously be positioned at its center. The membrane  32 ″′ is initially pre-stressed so that it tends naturally to return to its rest position. The fluid inside the reservoir  3  is thus subjected to a pressure exerted by the membrane  32 ″′. The fluid  3  is thus continually urged towards the dispensing orifice  21 . By looking at FIG. 8, it is easy to understand that the membrane  32 ″′ tends to return to a position in which it is substantially pressed flat against the front end wall  20 . It can be imagined that the membrane  32 ″′ has a plane or flat configuration in its rest position. 
     In this sixth embodiment represented in FIG. 6, the dispenser has a configuration substantially identical to that of FIG.  7 : the same numeral references have been used. The main difference with FIG. 7 is that the piston  32 ″ carrying the permeable partition  31 ″ is not biased by a spring. Initially, when the reservoir  3  is full, the piston may abut the bushing  220 . Thereafter, as the reservoir gets empty, the piston is moved by the air flow under pressure which pushes the piston and passes through the partition. Advantageously, the inner wall  221  of the drum  22 ″ may be formed with notches as a rack, thus preventing the piston from moving back. The pushing means of the movable wall of the fluid reservoir are here provided by the expelled air generated when the reservoir  10  is squeezed. 
     In the embodiments shown in FIGS. 6,  7  and  8 , the permeable partition  31 ″,  31 ″′ is associated with means making it possible to urge the fluid inside the reservoir  3  towards and through the dispensing orifice  21 . However, it is possible to imagine variant embodiments in which the permeable partition is not integral with, fixed to, or constituted by the means making it possible to deliver the fluid through the orifice  21 . However, it is preferable for the partition to move towards the dispensing orifice  21  so that the distance travelled by the entraining gas inside the fluid reservoir  3  becomes shorter as the dispenser is used. 
     The material used for the partition that is permeable to the gas and impermeable to the fluid may have a porous structure, a grating structure, a screen structure, or a lattice structure depending on the fluid to be dispensed. 
     By means of the invention, it is possible to obtain a two-phase gas/liquid or gas/powder dispenser that is of very simple design, that is of very low cost, and that is easy to use.