Abstract:
The device comprises a rigid container, a manual pump mounted on the container for dispensing in unit doses the product contained in the container and a filter for filtering outside air entering the container when the pump is actuated. The pump has no air intake in the container and the filter is arranged in an air intake passage provided in the base of the container, which is injection-moulded. The invention is useful for packaging and dispensing of fluids, in particular liquids, which need to be maintained germ-free.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the technical area of packaging, and more precisely the area of packaging a fluid product, in general liquid but which can also be in paste or gel form. The packaged product is intended to be kept germ-free without addition of a preservative, to be protected from oxidation, or to be sheltered from all external pollution, although in contact with the air, and also intended to be dispensed in unit doses by means of a manual pump. 
     More particularly, the object of the invention is a device for packaging and dispensing a product in unit doses. The device includes a container that is able to contain the product to be dispensed in unit doses by means of a manual pump, of the type without an air intake, which is mounted on the container while tightly sealing an opening in the container, for example, the open neck of a flask. 
     BACKGROUND OF THE INVENTION 
     Packaging and dispensing devices of conventional structure are known to comprise a container on which is fitted a manual pump for dispensing the product contained in the container. The pump generally includes a plunger which allows a piston to be moved by simple finger pressure in a pumping chamber, the volume of which determines the dose of the product to be dispensed. A first valve allows the chamber to be isolated from the internal volume of the container when the product is expelled from the chamber through a second valve. As a result of the movement of the piston caused by pressure on the plunger, the second valve allows the chamber to be isolated from the outside. When this chamber is filled via the first valve with a dose of the product coming from inside of the container, the dose is drawn into the chamber by the return of the piston towards its initial position. The dose of the product rests on a stop forming part of the pump body enclosing the pumping chamber, wherein the piston is caused to slide by elastic return means. 
     Thus, each time the piston returns to its starting position, reached by the effect of elastic return means, such as a spring, a dose of product is drawn into the pump chamber. 
     This suction of the product causes a partial vacuum inside the container. 
     For this reason, it is necessary to admit air from the outside into the container. This admission of air is generally provided through the pump. 
     The major disadvantage of this type of device lies in the fact that the admission of outside air to the interior of the container does not allow the product contained in the container to be kept sterile, to be protected from oxidation, or from all external pollution. 
     To remedy this disadvantage, different types of devices are proposed. For example, a device that comprises a pump without an air intake and a deformable container which contains the product to be packaged and dispensed by the pump has been proposed. The deformable container is an internal container around which a rigid external container is provided to ensure the mechanical protection of the deformable internal container. Each time a dose of the product is expelled from the deformable container, the partial vacuum created in the container causes contraction of the deformable container. In order for a device with a double container to function, it is necessary that the deformable internal container is able to retract. 
     For this reason, it is necessary to allow outside air to enter the space enclosed between the deformable internal container and the rigid external container. 
     This air intake can be provided near the neck of the container or at a passage at the bottom of the rigid container. 
     Further devices include an outside air intake circuit through the pump, which is fitted with a closing system which allows outside air to enter the space between the two containers when the pump is actuated. The closing system prevents vapors from the product, which have passed through the wall of the deformable container and are present in the space between the two containers, from escaping from this space to the outside when the pump is not being actuated. 
     A disadvantage of this type of device lies in the fact that it requires the use of a pumps including an air intake circuit, distinct from the product outlet circuit, and a closing system for the air intake circuit. Such a pump has a complex structure comprising a large number of parts that are intricate and difficult to fabricate. 
     Another disadvantage lies in the fact that when the deformable container has begun to retract it tends, through its own elasticity, to return to its starting position, thereby creating a partial vacuum within the product it encloses. 
     A consequence of this partial vacuum, principally when the product is a liquid or a fluid, and in particular a paste or a gel, is the appearance of a cavitation phenomenon leading to the formation of bubbles which impair the precision of the dosage. 
     Another type of a known device comprises a conventional container with a single rigid wall on which is fitted a pump with an air intake circuit. The air intake circuit includes a filter for sterilizing or absorbing the oxygen from the air, for keeping the product sterile, for protecting it from oxidation and for protecting the product from any external pollution. 
     In such a device, for example, FR-A-2 669 379, the outside air enters the container to compensate for the partial vacuum created by each action on the pump . This causes a dose of the product to be released such that it is filtered in a sterile manner. 
     The sterility of the product in the container is not, therefore, affected by contact with air coming from the outside. This is advantageous for the packaging and dispensing of pharmaceutical products. 
     The major disadvantage of this type of packaging device is the need to use a special pump, including a filter. The addition of the filter to the pump is a delicate and onerous operation, as it requires substantial structural modification to known pumps. 
     Packaging devices of this last type have been described, notably in FR-A-2 669 379, but, to the knowledge of the Applicant, none has been commercialized up to now. 
     A first objective of the invention is to propose a device for packaging and dispensing a product with a conventional container, a manual pump and a filter, which allows the use of standard dosing pumps that are available at low cost on the market. 
     Another objective of the invention is to propose such a device in which the creation of a partial vacuum inside a generally liquid product, paste or gel, is avoided, in order not to distort the dosage. 
     More generally, the objective of the invention is to remedy the disadvantages of similar devices representing the state of the art, and to propose such a device which meets the various practical demands better than known devices. 
     SUMMARY OF THE INVENTION 
     A device for packaging and dispensing a fluid product, which is generally liquid but may be, a paste or a gel. The packaging and dispensing device includes a container with a single rigid wall for containing the product to be packaged and dispensed, a manual pump mounted on the container for dispensing the product in unit doses, and a filter for filtering outside air entering the container when the pump is actuated. The pump has no air intake in the container and the filter is arranged in an air intake passage provided in the base of the container, which is injection-molded in a synthetic material. 
     Outside air can pass through the air intake passage and the filter, which is preferably sterile, and can compensate the partial vacuum created in the container when the user operates the pump. 
     The container is advantageously formed of two parts, a neck and a body. The neck has an open mouth on which the pump is mounted in a tightly sealing manner. The body with a base including the air intake passage which accommodates the filter, the two parts being injection-molded separately and then assembled in a sealed manner. 
     In a first, advantageously simple embodiment, the filter is mounted in a rigid sheath, preferably made of plastic and closely fitted to the filter. The outer shape of the sheath matches the part of the air intake passage in which the sheath is fixed by any appropriate means, such as pressure fitting, ultrasonic welding or snap-fitting. 
     Since sterile filters allow both gases and liquids to pass, a filter made of a hydrophobic filtering material will advantageously be chosen when the product to be packaged and dispensed is of an aqueous nature. A filter made of an absorbent filtering material will be chosen when the product for packaging and dispensing is of a non-aqueous nature. 
     Thus, when the product for packaging and dispensing is of an aqueous nature, the hydrophobic filter admits outside air but repels the product, which cannot escape to the outside thereby avoiding any risk of leakage. When the product for packaging and dispensing is of a non-aqueous nature, the absorbent filter admits outside air but repels the product which cannot escape to the outside. 
     In a variant, the device comprises a valve arranged between the filter and the internal space of the container for preventing any escape of the product contained in the container through the air intake passage and to avoid any contact between the product and the filter. 
     Advantageously, the valve is elastically deformable and cooperates with a conical seat, on the end, which is turned towards the inside of the container of a shaft formed integral with the base and defining the air intake passage in which the filter is retained. Such an elastic valve can efficiently oppose any escape of product to the outside of the container through the air intake passage, while admitting outside air by flexing elastically towards the inside of the container under the effect of the suction of outside air during the phase of pumping a dose of product from the internal space of the container. 
     Advantageously, the elastic valve is retained by a plug on the end of the shaft facing towards the inside of the container. In this case, the air intake passage may include grooves provided in the conical seat and the wall of an orifice in which the plug fixing the valve on the shaft is retained. 
     In these different variants, it is always advantageous for the filter, with its sheath if applicable, to be mounted in a conical central part of a shaft formed in one piece with the base of the container. 
     If it is desired to facilitate the injection-molding of the body of the container, starting from a central point in its base, it is advantageous that the conical central part of the shaft be closed towards the outside of the container by a base in which a hole for the air intake passage is provided eccentrically. 
     In another variant, which allows the maximum of the product contained in the container to be dispensed, the air intake passage opens to the inside of the container in the central part of a conical base of the container. The base widens towards the inside of the container permitting an optimum emptying of the container. 
     As the body of the container, like its neck, if applicable, is made of plastic using injection techniques, a perfect geometry can be advantageously obtained for the part of the air intake passage in which the filter is housed, for the conical seat on which the elastic valve is fitted and for other structural characteristics such as the grooves in the air intake passage. 
     With the objective of simplifying the manufacture of the filter, especially when it is sterile, commercial filters normally used in conjunction with a syringe and a needle can be used. These commercial filters are housed in a plastic sheath including a conical female part for assembling with the conical male outlet of the syringe and a conical male part for assembling with the conical female part of the needle. For this reason, it is advantageously proposed that the air intake passage includes a female conical part in which the male conical part of the filter sheath is assembled, if applicable, by a simple snap fit. 
     Other characteristics and advantages of the invention can be seen from the description given below, with reference to the attached drawings, which show, by way of non-limiting examples, embodiments of the construction and use of the object of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view in axial section of a first example of a device according to the invention, comprising a container made in two parts assembled together in a sealed manner, and cooperating with a manual pump for dispensing unit doses, a filter and a valve for protection of the filter against leakage of the product through the air intake passage; 
     FIG. 2 a is view in axial section of the two parts of the container before assembly; 
     FIG. 3 is an enlarged partial view in axial section showing the air passage with the filter and the valve, in the rest position, in the base of the container in a variant of the device in FIG. 1; 
     FIG. 4 is a view analogous to FIG. 3, in which the valve is shown in the open position admitting outside air; 
     FIG. 5 is a view in axial section of the base of the body of a variant of the container in which an air passage is provided which has a housing for receiving a filter; 
     FIG. 6 is an enlarged view in a partial section showing another variant of the base of the container body; and 
     FIG. 7 is a view analogous to FIG. 5 of yet another variant of the base of the container body, with an air intake passage in a conical base allowing the totality of the product contained in the container to be dispensed. 
     FIG. 8 is a view analogous to FIG. 3 showing yet another variant, with the filter arranged between the valve and the product in the container. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 1 and 2, the device for packaging and dispensing a product, for example a liquid, in unit doses comprises a container  15  with a single rigid wall formed in two parts, namely a body  15   b , of generally cylindrical form, closed by a base and open in its upper part, and a neck  15   a , of generally cylindrical-conical form tapering inwards towards the top, and joined in a sealed manner to the body  15   b . A dosing pump  13 , of a type without an air intake and of known general structure and operation, is mounted in a sealed manner on the open mouth  9  of the neck  15   a . A filter  26  for purifying the outside air entering the container  15  and of a sterile type is mounted in the conical part  19  of a central shaft  22  enclosing an intake passage for admitting outside air to the container  15 , and located in the base  35  of the body  15   b , a valve  17  being mounted on the end of the shaft  22  facing towards the inside of the container  15 . This valve  17  protects the filter  26  from the product contained in the container  15  and prevents any leakage of this product from the container  15  through the air intake passage. 
     The pump  13  comprises a body  32  having a cylindrical central part, in which slides a piston  3  having a central shaft by which the piston  3  is attached to a plunger  1  through which passes a dispensing passage  33 . A first valve  11 , with a sealing ball, operates in conjunction with a tapered seat  12  around a central opening in the base  34  of the cylindrical central part of the pump body  32 , to isolate the pumping chamber  8 , enclosed in this body  32  between the piston  3  and the base  34  of this body  32 , from the internal volume  20  of the container  15 . A second valve  2 , also with a sealing ball, cooperates with a seat  4 , also tapered, around the central opening in the shaft of piston  3  so as to isolate the pumping chamber  8  from the outside through the dispensing passage  33  in the plunger  1 . A helical compression spring  10 , extending inside the pumping chamber  8  between the lower part of the piston  3  and the base  34  of the pump body  32  returns the piston  3  to its rest position, against a stop projecting radially from the inside of the cylindrical part of the pump body  32 . In this rest position, the two valves  2  and  11  are closed and the pumping chamber  8  has its maximum volume. A plunger tube  14 , assembled by press fitting around a small sleeve on the lower part of the pump body  32 , allows the product to pass from the inside space  20  of the container  15 , close to the base of the latter, towards the inside of the chamber  8  when the valve  11  is open. 
     The central cylindrical part of the pump body  32  is engaged inside the open mouth  9  of the container  15 . An annular sealing gasket  5  is fitted around the pump body  32  and between a flanged shoulder  6  of the pump body  32  and the mouth  9  of the neck  15   a  to ensure a sealed fit between the pump body  32  and the mouth  9 . In addition, the flanged shoulder  6  of the pump body  32  has a step  7  projecting towards the inside of the pump body  32 . The flanged shoulder  6  allows the pump  33  to be attached to the container  15  by snap-fitting the step  7  of the pump body  32  into a corresponding peripheral groove  27  provided in the outside face of the mouth  9  of the neck  15   a  of the container. 
     The central shaft  22 , located at the center of the base  35  of the container body  15   b  with which the shaft  22  is formed in one piece, includes a tapered central female part  19  enclosing the air intake passage and in which the filter  26 , of the sterile type, is retained by press fitting or by any other assembly means such as ultrasonic welding. The shaft  22  has a double wall in this example, and comprises an outer wall surrounding its conical female part  19 . The lower end is formed in one piece with the base  35  of the body  15   b , while the upper end faces towards the inside of the space  20  and is formed in one piece with its conical female part  19 . The shaft  22  also has, on its upper end facing towards the inside of the space  20 , a tapered face  18 , which is very flared and widens towards the inside of the space  20 . The tapered face constitutes a seat against which the valve  17 , which has an elastically deformable membrane and has the form of a flat annular disc held on the shaft  22  by a plug  16 , bears in the closed position. This plug  16  has an enlarged head bearing on the face of valve  17  facing towards the inside of the space  20 . The plug also has a stem passing through the central opening in the annular valve  17  and firmly attached to the shaft  22  by press fitting of the stem of the plug  16  into an orifice in the shaft  22 . The orifice forms part of the boundary of the air intake passage, since this passage is never totally blocked by the plug  16 , so that outside air can always enter the inside space  20  of the container  15  by passing through the filter  26  in the shaft  22  when the valve  17  is lifted from its seat  18  by a partial vacuum in the space  20  following an actuation of the pump. 
     The assembly of the filter  26  and the valve  17  is shown in more detail in FIGS. 3 and 4, which show a variant in which the filter  26  is retained inside the central passage of a tubular sheath  23  , the outer shape of which can advantageously be tapered so as to be able to fit snugly into the conical female part  19  of the shaft  22 . A free space  24  remains between the top of the filter  26  and its sheath  23  and the underside of the central upper part of the shaft  22  which includes the seat  18 . Grooves  25  are provided in this central upper part of the shaft  22  to allow communication between the free space  24  and the face of the valve  17  located on the side of its seat  18  on the shaft  22 . The plug  16 , the lower part or stem of which is fixed firmly into the central upper part of the shaft  22  by press fitting in an axial orifice in this part which is adjacent to an axial groove  25 , has its upper part or head enlarged in the form of a disc enabling it to retain the central part of the valve  17  and forming a sealed joint in the rest position. The plug allows the peripheral part of the valve  17 , with elastic membrane, to lift to allow outside air to enter the container  15  to compensate a partial vacuum created in the container  15  when the user operates the pump  13 . 
     In FIGS. 3 and 4 the sheath  23  surrounding the filter  26  can be press-fitted into the conical part  19  of the shaft  22 . The geometrical form of which substantially matches the outer form of the sheath  23 , which is made of rigid plastic material and may also be welded ultrasonically into the shaft  22 . The sheath  23  may also be held in the shaft  22  by elastic snap-fitting of a peripheral snap ring on the sheath  23  into a matching groove in the conical part  19  of the shaft  22 . 
     As the body of the container  15   b  is made of plastic using injection techniques and is assembled in a sealed way on to the neck  15   a , also made of injected plastic, by ultrasonic welding or by any other appropriate assembly technique producing a sealed joint, an excellent geometry can be obtained for all the parts of the central shaft  22 , which is injection-molded with the body of the container  15   b . In particular an excellent geometry can be obtained for the conical seat  18  on which the elastic valve  17  bears and for the conical part  19  in which the filter  26  is housed surrounded by its conical sheath  23 , if applicable. 
     The device operates in the following manner: manual pressure exerted by the user on the plunger  1  moves the piston  3  against the spring  10  towards the base  34  of the pump body  32  thereby creating an overpressure in chamber  8 . This overpressure lifts the valve  2  permitting the product contained in the chamber  8  to escape to the outside by passing through the central shaft in piston  3  and then through the passage  33  in the plunger  1 , while the valve  11  is simultaneously closed, preventing any return of product contained in the chamber  8  towards the inside  20  of the container  15 . A dose of product is thus dispensed to the outside. 
     When the manual pressure on the plunger  1  is no longer exerted, the spring  10  returns the piston  3  to its initial rest position resting against the stop in the pump body  32  thereby creating a partial vacuum in chamber  8 . This partial vacuum closes the upper valve  2  preventing any outside air from entering the chamber  8 , and simultaneously opens the lower valve  11  allowing a new dose of product to enter the chamber  8  from the internal space  20  of the container  15 . 
     This induction of the product from the space  20  creates a partial vacuum inside space  20 . It is necessary to allow air to enter from the outside to compensate this partial vacuum. 
     Under the suction effect produced by the rising of the piston  3  in the pump body  32 , outside air enters the interior space  20  of the container  15  after successively passing through the filter  26 , the free space  24  and the grooves  25  (see FIGS.  3  and  4 ), and after having lifted the peripheral part of the elastic valve  17 , as shown in FIG.  4 . 
     When the partial vacuum created inside the space  20  is fully compensated by the air entering from outside, the suction ceases and the outside air no longer enters the container  15  through the filter  26 . Lifting the valve  17  which, through its inherent elasticity, comes into contact with the conical seat  18  of the shaft  22 , prevents the product in the space  20  from coming into contact with the filter  26  and prevents any leakage of product to the outside. 
     FIG. 2 illustrates the neck  15   a  and the body  15   b  which form the container  15  after sealed assembly. The neck  15   a  is a plastic part of a circular section of the profile of which allows injection-molding, so that extremely precise manufacture can be achieved. This enables very precise forming of the mouth  9  on which the sealing gasket  5  bears, the groove  27  for engaging with the matching step  7  in the pump body  32  as well as the wider part of the neck  15   b , the diameter of which matches that of the corresponding part of the body  15   b . The neck  15   a  is assembled to the body  15   b  by means of ultrasonic welding, for example. On this part of the neck  15   a  a circular step  28  allows the ultrasound to focus better by acting as an energy guide. The body  15   b  is also a part of circular section produced by injection-molding with the same plastic as the neck  15   a , so that it can be easily assembled with the neck  15   a  by ultrasound. A circular step  29 , also acting as an energy guide, is formed in the body  15   b  opposite the step  28  in the neck  15   a , allowing easy and watertight welding between the neck  15   a  and the body  15   b.    
     In the base  35  of the body  15   b  the simple shape of the shaft  22  also allows injection-molding, and therefore allows precise forming of the tapered inside face of the conical part  19  of the shaft  22 , for assembly by interlocking or by any other means, such as ultrasonic welding. The shape of the shaft also allows for precise forming of the sheath  23  of the filter  26 , of the orifice  31  (FIG. 2) for assembly by press-fitting to the plug  16 , of the grooves  25  (FIGS. 3 and 4) and of the conical seat  18  on which the lower face of the elastic valve  17  rests. 
     The design of the container  15  in two parts  15   a  and  15   b  can be formed in plastic, such as polypropylene, for example, by injection-molding, allows the goal of the invention to be achieved. More specifically the part  19  of the shaft  22  of the container  15  in which the filter  26  is housed, the part of the shaft  22  of the container which forms the seat  18  on which the valve  17  is located and the orifice  31  in which the plug  16  for holding the valve  17  is inserted while leaving an air passage are precisely formed. 
     In the variant in FIG. 5, the shaft  22 , with a single wall and integrated by its lower end with the base of the container  15 , still has a tapered central passage narrowing towards the inside of the container  15 . The tapered central passage can receive the filter  26 , if applicable, without the sheath  23  in FIGS. 3 and 4, but no valve is fitted to the shaft  22 . In this structure, still more simple to produce, the sterile filter  26  can be of the hydrophobic type when an aqueous product is packaged in the container  15  or an absorbent filter in the opposite case. 
     FIG. 6 shows another variant of the base  35  of the container and of the central part of the shaft  22  of the outside air intake. In this embodiments the shaft  22  has a double wall and is still integrated with the base  35  by the lower end of its outer wall. The shaft  22  includes a base  36  forming part of its wall or an internally conical central part  19 , for receiving the filter and, in this example, widening towards the inside of the container  15  and no longer towards the outside of the container, as shown in the other embodiments. To allow outside air to enter the container, an eccentric hole  37  is provided in the central part of the base  26  and, although not shown in FIG. 6, an elastic valve may be fixed to the top of the shaft  22 , so as to cooperate with the tapered seat  18  in which, as in the example in FIGS. 3 and 4, at least one groove  25  forming an air passage is provided and is extended into the inside face of the conical central part  19 . 
     The advantage of this embodiment lies in the possibility of injecting the plastic into the center of the base  36  when producing the body  15   b  thereby allowing a better dispensing of the material and the production of a part which is almost perfectly cylindrical. 
     In FIG. 7 the flat base  35  of the container  15  in the examples described previously has been replaced by a conical base  30 . The conical base allows more of the product to be dispensed at the end of use than when the base is flat. In particular, the conical base  30  narrows towards the bottom and the outside of the container  15  through its central part that is formed in one piece with the upper end of the central shaft  22 . The central shaft  22  has a single wall and a tapered central passage to house the filter  26  in the air intake passage passing through the shaft  22  and the center of the base  30 . Through its conical form, the latter at the same time forms a seat for an elastic valve such as the valve  17  in FIGS. 3 and 4, if applicable. In this variant, the length of the plunger tube  14  may be limited by the presence of the shaft  22 , and this latter, although projecting below the base  30 , is protected by the prolongation of the side wall of the container body  15  below the base  30 . 
     Other embodiments of the base are possible without departing from the scope of the invention. 
     It also does not go outside the scope of the invention to form the container  15  in one piece for packaging small volumes of a product, since in this case the diameter of the container is small and allows a pump to be attached directly to the body of the container. 
     When the diameters of the container body are larger and do not allow the pump to be attached directly to the body, the addition of an intermediate part such as a linking ring between the pump and the body to allow the pump to be attached is a means equivalent to adding a neck such as  15   a  to a body such as  15   b  of the container.