Abstract:
A dispenser device without any air intake, such as an airless pump, for dispensing a fluid substance, the device comprising a dispensing chamber ( 14 ) of variable volume, which chamber is provided with an inlet ( 12 ) equipped with an inlet valve member ( 51, 53 ), and is provided with an outlet equipped with an outlet valve member, the dispenser further comprising a piston ( 3 ) for causing the volume of the dispensing chamber ( 14 ) to vary, closure elements ( 51; 52; 55; 63 ) being provided to close off the dispensing chamber ( 14 ) in airtight manner, substantially at its inlet ( 12 ), prior to it being used for the first time, the device being characterized in that the closure elements are formed by the inlet valve member ( 51, 53 ).

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an airless dispenser device such as an airless pump, i.e. a pump without any air intake, so that the substance to be dispensed never comes into contact with air until it is dispensed. Such an airless pump is used, in particular, for dispensing substances that are liable to deteriorate on coming into contact with air. Such substances can be pharmaceuticals or cosmetics. 
     Conventionally, that type of dispenser comprises a dispensing chamber of variable volume, which chamber is provided with an inlet equipped with an inlet valve, and is provided with an outlet equipped with an outlet valve. In order to vary the volume of the dispensing chamber, a piston is provided that is generally actuated by means of an actuator rod through which the substance is delivered from the chamber. That is a quite conventional design for an airless pump. 
     In order to avoid any possibility of the substance to be dispensed being deteriorated by coming into contact with air, it is preferable to fill the container under a vacuum, and to mount the dispenser device on the container while it is still under a vacuum. During the operation of mounting the dispenser on the container under vacuum conditions, the inside of the dispenser, and in particular the dispensing chamber, is also subjected to the vacuum. The air is evacuated from the dispensing chamber via the inlet valve whose valve member can be in the form of a ball, of a washer, or of a conical flange member, which valve member does not provide good airtightness during this operation of fixing the dispenser under a vacuum. The valve seat does not have a surface state that is good enough to guarantee good airtightness. Therefore, air is also evacuated from the dispensing chamber and a partial vacuum then prevails therein. It should be noted that, during this step of mounting the dispenser on the container, the dispenser head is not yet mounted on the actuator rod of the dispenser. When the vacuum is interrupted, once the dispenser has been fixed to the container, the container and the pump are once again subjected to atmospheric pressure, so that all of the empty spaces inside the container and also inside the dispensing chamber are suddenly filled with the substance contained in the container. The dispensing chamber is thus at least partially filled. A major drawback then occurs when the dispenser head is mounted on the actuator rod, since mounting the head causes the rod to be displaced, which in turn causes the piston to be displaced, thereby reducing the volume of the dispensing chamber which is at least partially filled with the substance. As a result, substance contained in the dispensing chamber is dispensed. Therefore, prior to the device being sold and being used for the first time, the actuator rod and the expulsion channel in the dispenser head are filled with substance. That substance is then naturally in contact with the outside air, and can thus deteriorate. 
     Attempts have been made to solve that problem of substance being dispensed while the dispenser head is being mounted. Some such attempts consist in inserting a gas into the chamber before the dispenser is returned to atmospheric pressure. However, such a method is very difficult to implement because of the small diameter of the internal channel in the actuator rod, since it is necessary simultaneously to push back the outlet valve member and to inject the gas into the chamber. Such a gas injection method is therefore very difficult to implement. 
     Document EP-0 753 353 discloses a dispenser whose inlet tube is formed with a stopper that closes it off. When it is used for the first time, the stopper is punched out by an extension to the actuator rod, which extension penetrates into the inlet tube. The stopper is integrally molded with the inlet tube, which complicates molding. In addition, once it has been punched out, the stopper is free to move inside the inlet tube, and there is therefore a risk that said stopper might hinder dispenser operation. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to mitigate that drawback of the prior art by defining a dispenser whose inlet is initially closed off by a stopper that is easy to put in place, without complicating the molding, and that cannot hinder dispenser operation once it has been dislodged from its closure position. 
     To this end, the present invention provides a dispenser device without any air intake, such as an airless pump, for dispensing a fluid substance, said device comprising a dispensing chamber of variable volume, which chamber is provided with an inlet equipped with an inlet valve member, and is provided with an outlet equipped with an outlet valve member, said dispenser further comprising a piston for causing the volume of the dispensing chamber to vary, closure means being provided to close off the dispensing chamber in airtight manner, substantially at its inlet, prior to it being used for the first time, the closure means being formed by the inlet valve member. 
     Since the outlet valve has good airtightness, the inlet closure means make it possible to isolate the dispensing chamber from the outside air with good airtightness. It is thus impossible for an air vacuum to establish itself inside said chamber. 
     Using the inlet valve member itself as closure means offers the advantage of not adding any additional parts to the dispenser. 
     In order for the dispensing chamber to be put back into communication with the container, the piston is mounted on an actuator rod having an end that projects into the dispensing chamber, said end forming a pusher member suitable, at the end of its stroke, for pushing the inlet valve member from its airtight position into its normal working position. 
     In a first practical embodiment, the inlet valve member is a ball wedged in airtight manner in a sleeve. 
     In a variant, the inlet valve member is a member having a conical flange and provided with a projecting peripheral sealing bead wedged in the inlet of the dispensing chamber. 
     Thus, the dispensing chamber is well isolated from the outside, and thus it is not subjected to the vacuum that prevails at the time of fixing the dispenser to the container. The closure means are released only on mounting the dispenser head onto the actuator rod, which causes the rod to be displaced inside the chamber until its end displaces the closure means in order to establish communication between the chamber and the container. 
     By using the inlet valve member to close off the inlet, it is not necessary to mold a stopper, as it is in the prior art, and, once the valve member has been dislodged, there is no danger of it hindering dispenser operation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is described more fully below with reference to the accompanying drawings which give a plurality of embodiments of the present invention by way of example. 
     In the drawings: 
     FIG. 1 a  is a longitudinal section view through a first embodiment of a dispenser; 
     FIGS. 1 b  and  1   c  are longitudinal section views through the dispenser of FIG. 1 a  during the step of mounting the dispenser head, so as to show how the closure means are released; and 
     FIGS. 2 a  and  2   b  are longitudinal section views through a second embodiment of a dispenser of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is made below to FIG. 1 a  in order to explain the structure of the dispenser of the invention. In both of the embodiments described, it is an airless pump, i.e. it does not allow any air to be sucked in as the product is being dispensed. It is therefore necessary for the container (not shown) to be capable of reducing its capacity as the product is being extracted from it. It can thus be a container in the form of a flexible pocket or a container equipped with a follower piston. The internal structure of the airless pump is not critical for the invention and is therefore not described in detail herein. However, in the embodiments shown, this airless pump comprises a body  1  defining a cylinder  10  slidably receiving a piston  3  mounted on an actuator rod. The bottom end of the body  1  is provided with an inlet  12  defining a frustoconical valve seat  13 . At its top end, the body  1  forms a fixing flange  11  which projects radially outwards. This flange  11  enables the pump to be held by means of a crimpable ring  83 . For the purposes of sealing the pump to the container (not shown), two annular gaskets  81  and  82  are placed respectively between the flange  11  and the crimpable ring  83 , and between the top end of the container (not shown), and the crimpable ring  83 . The pump is thus fixed to the neck of the container (not shown) in fully airtight manner. As mentioned above, the cylinder  10  that forms the body  1  receives a piston  3  which is itself slidably mounted on the actuator rod  2 . The piston  3  is urged into its rest high position shown in FIG. 1 a  by a return spring  7  which acts via a plunger  4  that bears against the piston  3 . In addition, the actuator rod  2  is urged into its rest position shown in FIG. 1 a  by a spring  4  that bears against the piston  3 . In conventional manner, the actuator rod  2  defines an outlet duct  21  which defines two side openings  22  in the vicinity of its bottom end, which openings are closed off by the piston when it is in the rest position (FIG. 1 a ). The arrangement formed by the bottom end of the actuator rod  2 , by the piston  3 , and by the plunger  4  constitutes the outlet valve member of the airless pump. Below this arrangement, the pump body  1  forms a pump chamber  14  of variable volume. At its bottom end, the pump chamber is provided in conventional manner with an inlet valve member  51  which, in FIG. 1 a , is in the form of a spherical ball. Other forms of inlet valve member may be considered, such as, for example, a member with a conical flange (FIGS. 2 a  and  2   b ). 
     The design of the above-described airless pump is quite conventional and is common to both of the embodiments. Naturally, other designs may be considered for the structure of the pump without going beyond the ambit of the present invention. 
     As can be seen in FIG. 1 a , the ball  51  does not rest on its valve seat  13 , but rather it is engaged in a sleeve  61  in which it is wedged. The sleeve is formed by a substantially cylindrical part  6  engaged inside the body  10 , and resting against the bottom of the body by being pressed thereagainst by the spring  7  which bears via its bottom end  71  against said part. As a result, the cylindrical part  6  is held firmly inside the body  10 . The cylindrical part  6  further defines side drains  62  through which the substance can pass. In the position shown in FIG. 1 a , the inlet valve member  51  does not rest on its seat  13  so that it cannot perform its function of selectively closing the inlet  12  of the pump chamber  14 . The pump chamber  14  is fully isolated from the outside in airtight manner. As described above, the ball  51  wedged in the sleeve  61  prevents any air from passing through via the inlet of the pump chamber, and the piston  3  being positioned over the side openings  22  in the actuator rod  2  prevents any air from passing through via the outlet valve of the pump chamber  14 . Therefore the pump chamber  14  defines an isolated space. 
     As described above in the introduction, during the operation of mounting the pump under a vacuum onto the neck of a full container, the entire pump and the entire container are disposed in an enclosure from which the air has been evacuated to form an air vacuum. By isolating the pump chamber  14  from the outside in fully airtight manner, said chamber is not subjected to an air vacuum during the mounting operation performed under a vacuum. When the outside pressure decreases, as it does when an air vacuum is formed, the outlet valve remains fully closed in airtight manner and the ball  51  wedged firmly in the sleeve  61  also guarantees full airtightness, so that, when the air vacuum is interrupted, and the dispenser as a whole and as equipped with the container filled with the substance is once again at normal atmospheric pressure, the substance contained in the container cannot rise into the pump chamber  14  because its inlet is closed off by the presence of the ball  51  wedged in the sleeve  61 . This thus ensures that the pump chamber  14  remains filled with air at atmospheric pressure, and that no substance finds its way into the chamber  14 . 
     Thus, after the vacuum filling operation, the airless pump is as shown in FIG. 1 a . In this state, the pump is unusable because the ball  51  closes off the inlet of the pump chamber  14 . In order to bring the pump into an operational state, it is necessary for the ball  51  to take up its normal working position against the conical inlet valve seat  13 . To achieve this, it is necessary merely to push the ball  51  downwards to release it from being wedged in the sleeve  61 . With reference to FIGS. 1 b  and  1   c , a description follows of how it is possible to release the ball  51  from its airtight wedging in the sleeve  61 . Once the mounting operation of crimping the pump to the container under a vacuum has been performed, the next conventional step is to mount the dispenser head  9  onto the actuator rod  2 . A conventional dispenser head comprises a connection sleeve  91  defining an internal channel  92  which is extended sideways by an outlet duct  93  terminating in a dispenser nozzle  94 . Outwardly, the dispenser head  9  may form a peripheral skirt  96  that extends downwards to mask a portion of the pump and of the actuator rod  2 . To fit the dispenser head  9  onto the actuator rod  2 , it is necessary to position the sleeve  91  in alignment with the rod  2 , and then to exert thrust against the surface  95  of the head  9  in order to achieve the interfitting shown in FIGS. 1 b  and  1   c . When the thrust is exerted against the surface  95 , the actuator rod  2  is urged downwards inside the body of the pump, while entraining the piston  3  with it. By penetrating further into the body  1  in this way, the actuator rod reduces the volume of the pump chamber  14  against the action of the return spring  7 . As the actuator rod  2  penetrates further into the body, the piston  3  and the plunger  4  move over the rod in the opposite direction so as to uncover the side openings  22 , thereby establishing passageways through which air can pass between the pump  14  and the outside via the channel  21 , the duct  92  and the duct  93 . In other words, the outlet valve opens when the pressure inside the pump chamber  14  is high enough to push the piston  3  back and uncover the side openings  22 . If the pushing on the actuator rod  2  is continued, said rod continues its stroke inside the pump body until its bottom end  23  comes into pushing contact against the ball  51  wedged in the sleeve  61 . By exerting sufficient pressure, it is possible to cause the end  23  of the rod  2  to dislodge the ball  51  from its sleeve  61 , as shown in FIG. 1 b . By continuing to push on the actuator rod  2  until the sleeve  91  of the head  9  comes into abutment against the crimpable ring  83 , it is possible to cause the bottom end  23  of the rod  2  serving as a pusher member to release the ball  51  completely from the sleeve  61 , so that the ball can come into position against the conical inlet valve seat  13 , which position constitutes its normal working position, enabling the inlet  12  of the pump chamber  14  to be selectively closed off. 
     To sum up, the inlet valve member, constituted by a ball  51  in this example and that acts as closure means to isolate the chamber  14  during the crimping operation performed under a vacuum, is then pushed into its normal working position by means of the bottom end of the actuator rod  2  serving as a pusher member on mounting the dispenser head  9  onto said actuator rod  2 . Therefore, it is possible to release the ball  51  form its sleeve  61  without using any additional parts and without performing any additional operations, because mounting the actuator head  9  onto the rod  2  is an operation that is conventional and necessary. 
     A secondary advantage further results from using the cylindrical part  6  to form the sleeve  61  serving to wedge the ball  51 . The cylindrical part  6  can co-operate with the valve seat  13  to define a space constituting a housing in which the ball  51  is held captive, so that its freedom of movement is limited. This thus ensures that the ball  51  always comes accurately into position against its valve seat  13 . 
     Compared with a conventional airless pump known from the prior art, the only difference lies in the use of the cylindrical part  6  to wedge the ball. It is very simple to mold and to put in place, without any extra cost or any major technical investment. When mounting the pump, the ball  51  is pre-engaged by force in the sleeve  61  formed by the cylindrical part  6 , and then the resulting assembly is merely inserted into the body of the pump  1 . It can thus be understood that it is very simple to release the closure means without using either any additional parts or any additional operations. 
     FIGS. 2 a  and  2   b  show a variant of the inlet valve in the form of a member  53  provided with a conical flange  54  serving to co-operate with the conical surface  13  of the valve seat. The closure function performed by the closure ball  52  is then performed by a projecting peripheral sealing bead  55  suitable for being positioned in the inlet  12  in the same way as the ball  52 . When mounting the dispenser head  9  shown in FIG. 2 b , the member  53  is then merely pushed by the pusher stud  23  that forms the bottom end of the actuator rod  2 , so that the bead is released from the inlet  12  and so that the conical flange can then come into airtight abutment against the conical surface of the inlet valve  13 . The use of such a valve member instead of the balls  51  and  52  offers several advantages. Firstly, it constitutes a one-piece part rather than two separate parts, so that the means serving to close off the inlet remain connected to the means serving as valve member, whereas when a closure ball  52  is used, it is expelled into the container. Secondly, such a member can be made of molded plastics, which is firstly less costly and secondly advantageous in terms of recycling capacity. 
     By means of the invention, it is possible to isolate the dispensing chamber  14  in fully airtight manner during a fixing operation, in particular a crimping operation, performed under a vacuum, and to do so very simply. Furthermore, the closure means can be released very simply without any additional operation or any additional member being required.