Abstract:
A device for the dosed output of a medium from a container through an opening in an upper housing part. A valve piston tip is associated with said opening for the closing thereof. A piston surface, which is pressed against a spring, is adjacent to the valve piston tip and is used as part of a valve piston, which is sealingly guided in a piston chamber in the upper part of the housing and forms a filling chamber which is connected to the container, between the upper part of the housing and the opening.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a device for the metered dispensation of a medium from a container through an opening in an upper housing part, with the opening being assigned a valve piston tip in order to be closed off, and with the valve piston tip as part of a valve piston being adjoined by a piston face which is supported against a spring, is sealingly guided in a piston space in the upper housing part and forms a filling space between itself and the opening, which filling space is connected to the container.  
         [0002]     Flexible bottles are known for example for eye droplets from which a droplet can be dispensed in the manner of a pipette into the eye. This is cumbersome and imprecise.  
         [0003]     A spray device is for example known from EP 0 688 608 A1, in which spray device a dispensing opening is closed off by a valve piston tip. Said valve piston tip is part of a valve piston which is mounted so as to be supported against a spring. The medium can be introduced through the interior of the valve piston and through corresponding openings in the valve piston into a filling space, with a pressure being exerted on a piston face, which has the effect that the valve piston is moved counter to a spring, and the valve piston tip thereby opens the dispensing opening.  
         [0004]     The present invention is based on the object of developing a device of the above stated type with which a medium can be metered in a simple and precise manner.  
       SUMMARY OF THE INVENTION  
       [0005]     In order to achieve the object, it is provided on the one hand that a compressible element is arranged in the filling space.  
         [0006]     Said compressible element can for example be an air ring or the like. It is important that the element can be compressed under pressure. The different possible embodiments of the compressible element, that is to say as an air ring, as a ball or the like, are to be encompassed by the present invention.  
         [0007]     If the medium then flows, as a result of the pressure exerted on the container, through the duct and the recess in the valve piston into the filling space, then the element is compressed under the pressure of the filling space. The compressed medium subsequently pushes the valve piston open. At the same time, the element which is compressed by the medium can relax and the medium is pushed out of the filling space and out through the opening.  
         [0008]     It is provided in a further exemplary embodiment that the connection between the container and the filling space is produced by means of a duct which bypasses the valve piston. The valve piston is opened only when the filling space is filled. This is provided by virtue of pressure being exerted on the container. If the pressure is removed, the opening is automatically closed.  
         [0009]     In one preferred exemplary embodiment, however, the connection between the container and the filling space is produced by a duct and a recess in the valve piston itself. Here, it should be possible for said duct to be closed off, specifically at the moment at which the filling space is filled and the opening is opened. If the flow of the medium is now interrupted, the spring-mounted valve piston is returned to its initial position, thereby ejecting a precisely metered quantity out of the opening. For this purpose, the valve piston tip is also formed from two cones, with the first cone interacting with a metering space which is formed by the opening. The second cone serves to seal off the filling space from the external surroundings.  
         [0010]     This permits a hydraulic, pressure-controlled opening of the opening for metering the medium. If the pressure is removed, the opening automatically closes, this taking place under the pressure of the spring. A microbiologically sealed metering system is provided in this way.  
         [0011]     Also to be encompassed by the present invention is the possibility in any exemplary embodiment of using, instead of the springs, other force stores which can perform the function of a spring.  
         [0012]     In order to simplify the use of the device for the metered dispensation of a medium in particular in the case of eye drops, a further embodiment of the device according to the invention provides arranging the container at approximately 90° with respect to the upper housing part or to the lower housing part. In the present case, the embodiment has been shown by way of example only on the basis of one of the exemplary embodiments of the device for the metered dispensation of a medium. The other exemplary embodiments of the device for the metered dispensation of a medium can of course also be used.  
         [0013]     It is likewise entirely conceivable, depending on the field of application of the device, to provide an angle other than 90°. It is thus for example conceivable, with a corresponding arrangement of the duct, to provide a perpendicular arrangement of the container on the upper housing part. The different possibilities for the arrangement of the container on the upper housing part or the lower housing part are to be encompassed by the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     Further advantages, features and details of the invention can be gathered from the following description of preferred exemplary embodiments and on the basis of the drawing, in which:  
         [0015]      FIG. 1  shows a longitudinal section through a device according to the invention for the metered dispensation of a medium;  
         [0016]      FIG. 2  shows a partially illustrated longitudinal section through a further exemplary embodiment of a device according to the invention for the metered dispensation of a medium;  
         [0017]      FIG. 3  shows a partially illustrated longitudinal section through a further exemplary embodiment of a device according to the invention for the metered dispensation of a medium;  
         [0018]      FIG. 4  is an enlarged illustration of a partial longitudinal section through an opening region of the device as per  FIGS. 2 and 3 , in the closed position;  
         [0019]      FIG. 5  is an enlarged illustration of a partial longitudinal section through the opening region as per  FIG. 4 , in the open position; and  
         [0020]      FIG. 6  shows a partially-illustrated longitudinal section through a device according to the invention for the metered dispensation of a medium as per  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0021]     In  FIG. 1 , a device according to the invention for the metered dispensation of a medium has an upper housing part which is placed on a container  5 . The medium to be dispensed, for example a liquid, is situated in said container  5 .  
         [0022]     Seated in the upper-housing part  1  is a valve piston  3  which, with a valve piston tip  12 , closes off an opening  17 . The valve piston  3  also has a piston face  9  which bears sealingly against an inner wall  19  of an insert  20  which is inserted into the upper housing part  1 . The piston face  9  is adjoined by a sleeve section  21  which holds a spring  4  which is supported at the other side against an insert base  22 . The sleeve section  21  ends with a projection  23  which likewise bears against the inner wall  19 .  
         [0023]     Formed above the piston face  9  is a filling space  18  which is connected by means of a duct  6  between the insert  20  and the upper part  1 , and a duct section  24 , to the interior of the container  5 .  
         [0024]     The present invention functions as follows:  
         [0025]     When the compressible container  5  is actuated, the medium is pushed via the duct section  24  and the duct  6  into the filling space  18 . The medium pushes against the piston face  9 , so that the valve piston  3  moves downward counter to the pressure of the spring  4 , and the filling space  18  is enlarged. The valve piston tip  12  thereby leaves the opening  17 , with it being possible for the liquid flow and the dispensation volume to be controlled by means of the design of the valve piston tip and of the upper housing part  1  or of the opening  17 . A valve piston stop  11  is also provided in the insert  20 , which valve piston stop  11  in interaction with the projection  23  serves to likewise determine the opening cross section and therefore control the throughput of the medium.  
         [0026]     In the exemplary embodiment of one device according to the invention for the metered dispensation of a medium as per  FIG. 2 , a lower housing part  2  is situated between the container  5  and the upper housing part  1 . Provided on said lower housing part  2  are latch-in grooves  16  for connecting to the upper housing part  1 , by means of which latch-in grooves  16  a complete metering system is formed, that is to say the upper housing part  1  and the lower housing part  2  are connected in a non-destructive manner.  
         [0027]     Here, a valve piston  3 . 1  has the piston face  9  which is supported directly via the spring  4  against the lower housing part  2 . A sleeve section  21 . 1  and a projection  23 . 1  also move in said spring  4 . Said projection  23 . 1  however has a cross-sectional face which is considerably smaller than the piston face  9 . In addition, said cross-sectional face interacts with a cone  25  which projects from the lower housing part  2 . An outlet window  7  of a duct  6 . 1  can be seen on the cone  25 , via which medium can exit through the outlet window  7  into the valve piston  3 . 1 . The medium can flow through a recess  26  into the valve piston  3 . 1  and passes out through a further window  8  into the filling space  18 .  
         [0028]     This exemplary embodiment of the device according to the invention functions as follows:  
         [0029]     If the bellows or the squeeze-bottle as a container  5  is acted on with the pressure of a finger, the displaced medium flows via the duct  6 . 1  through the window  7  into the recess  26  of the valve piston  3 . 1 , and via the window  8  into the filling space  18 . The spring-loaded large piston face  9  with a sealing lip is in system internal pressure against the small piston face of the projection  23 . 1 , so that the hydraulic pressure which is exerted opens the valve counter to the spring force.  
         [0030]     The return stroke of the piston face  9  is delimited by the abutment of the projection  23 . 1  against the cone  25 , as a result of which the medium flow is also interrupted by the areal contact of the projection  23 . 1  against the cone  25  and the sealing lip action of the projection  23 . 1 . As a result, the filling space  18  is returned to an unpressurized state, so that the spring force of the spring  4  can move the valve piston  3 . 1  into the initial position. Here, the stroke of the valve piston  3 . 1  moves medium to the opening  17 , and the valve piston tip  12  pushes the droplet metered in a metering space  13  (see  FIG. 5 ) out of the opening  17 . As a result of a drip edge  14  or face  15  on the valve piston  3 . 1  and the upper housing part  1 , the droplet releases from the system in the overhead position. As a result of the valve piston movement in the direction of the opening  17 , the metered droplet is pushed out of the upper housing part  1  and, at the same time, the valve piston tip  12  closes off the system in a microbiologically sealed fashion by means of the spring  4 .  
         [0031]     The drip edge  14  or face  15  and the liquid output are defined by the geometry of the valve piston tip  12 , which is formed from two cones, and by the opening  17  or the upper housing part  1 .  
         [0032]     A further embodiment of the device according to the invention for the metered dispensation of a medium is shown in  FIG. 3 . Here, an air ring  27  is arranged in the filling space  18  above the piston face  9  and around the valve piston  3 . 1 . The air ring  27 , as is apparent from the name, is filled in its interior with air, as a result of which it is compressible.  
         [0033]     For the remaining description, reference is made for simplicity to the description regarding  FIG. 2 .  
         [0034]     The functioning of said exemplary embodiment of the device according to the invention is likewise similar to the functioning of the previously described exemplary embodiment, for which reason reference is made thereto at this point. A new feature of this embodiment is however that the air ring  27  is compressed as the medium is forced into the filling space  18 . After overcoming the force of the spring  4 , the medium also pushes open the valve piston  3 . 1  which is under preload, so that the air ring  27  can relax and assists the dispensation of the medium out of the filling space  18 . Since the filling space  18  is now unpressurized, the spring force of the spring  4  moves the valve piston  3 . 1  into its initial position. As a result of the stroke of the valve piston  3 . 1 , the valve piston tip  12  pushes the droplet situated in the metering space  13  out of the opening  17 . As a result of the drip edge  14  or face  15  on the valve piston  3 . 1  and the upper housing part  1 , the droplet releases from the system in the overhead position. As a result of the valve piston movement in the direction of the opening  17 , the metered droplet is pushed out of the upper housing part  1  and, at the same time, the valve piston tip  12  closes off the system in a microbiologically sealed fashion by means of the spring  4 .  
         [0035]     In order to simplify the use of the device for the metered dispensation of a medium in particular in the case of eye drops, a further embodiment of the device according to the invention provides arranging the container  5  at an angle w of approximately 90° with respect to the upper housing part  1 , as illustrated in  FIG. 6 . In the present case, the embodiment has been presented by way of example only on the basis of the device for the metered dispensation of a medium in  FIG. 2 . The exemplary embodiments of the device for the metered dispensation of a medium as per  FIGS. 2 and 3  can of course also be used. In said case, the container  5  would then be arranged on the lower housing part  2 .  
         [0036]     Said embodiment does not provide any change in the mode of functioning, so that reference is made at this point to the above description.