Abstract:
A metering pump arrangement has a container with a changeable volume for accommodating a fluid. The arrangement has a pump that can be connected with the container in a sealed manner, which can be manually activated. The pump has an outlet opening that is connected with the surroundings. A bypass channel runs outside the pump and connects the container with the surroundings. The bypass channel can be sealed off by way of a closure element. The arrangement may be used for metering, dispensing or applying cosmetics or pharmaceuticals. A method is also provided for producing a metering pump arrangement.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     Applicant claims priority under 35 U.S.C. §119 of German Application No. 10 2004 020 152.8 filed Apr. 24, 2004.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a metering pump arrangement or assembly having a container with a changeable volume, for accommodating a fluid. The arrangement has a manually-activatable pump that can be connected with the container in sealed manner, and has an outlet opening that is connected with the surroundings. The present invention also relates to the use of such a metering pump arrangement, as well as to a method for its production.  
         [0004]     2. The Prior Art  
         [0005]     A dispensing device for fluids is known from DE 100 49 898 C2, with which fluid pharmaceuticals or cosmetics, for example, can be dispensed from a container by being metered. The metering pump used for this purpose works without any air equalization, whereby the fluid within the container is accommodated in an inner bag that is sealed with regard to the surroundings, which bag collapses as it empties.  
         [0006]     Filling such inner bags with fluids, such as pharmaceuticals or cosmetics, usually takes place in that residual air remains in the inner bag. This arrangement is undesirable for various reasons. For example, oxygen is constantly in contact with the fluid during storage, and this contact results in reducing the storage period or the absence of germs in the fluid. However, filling the fluid container in a germ-free atmosphere or under protective gas is very complicated and expensive.  
         [0007]     Furthermore, complete emptying of the bag is possible only if no residual air remains in the inner bag after it is filled. The residual air in the inner container has a disruptive effect if the dispensing device is not held straight during activation. Thus, the pump can draw in residual air if the metering pump arrangement is not held completely vertically, and this residual air will be dispensed from the inner bag instead of the fluid. This dispensing of residual air is particularly undesirable in the case of the administration of medications, such as ear, nose, and throat sprays, for example, where administration with the dispensing device held precisely vertically is possible only with great difficulty.  
         [0008]     DE 100 49 898 C2 therefore proposes to form a passage between the outer wall of the piston and the inner wall of the pressure cylinder of the metering pump for the residual air to be drawn off. The passage is connected with the inner bag by way of an opening provided on the pump housing, and with the surroundings by way of a valve-like flap within the pump. By means of this channel within the pump, any residual air that remains after the inner bag has been filled can be drawn off, in order to avoid the disadvantages mentioned above. However, the formation of this channel for the residual air in the inner bag presupposes a high level of precision in the production of the pump. Furthermore, the production of this known dispensing device becomes more expensive because of the complicated structure of the pump.  
       SUMMARY OF THE INVENTION  
       [0009]     Against this background, it is an object of the present invention to provide a metering pump arrangement of the type stated initially, in which the residual air remaining in the container when it is filled can be drawn off using simple means. Another object is to provide a simplified method for the production of such a metering pump arrangement.  
         [0010]     These and other objects are accomplished, in accordance with the invention, by providing a bypass channel that runs outside the pump, that connects the container with an outside area or the surroundings, and that can be sealed off by way of a closure element. Because the bypass channel is not integrated into the pump itself, the structure of the pump can be kept particularly simple. This arrangement makes it possible to use inexpensive and simple pumps. Furthermore, because of the separation of the pumping function from the suctioning function for the residual air, a large number of different pumps can be used. In this way, the selection of the pump can be individually coordinated with the purpose of use. At the same time, the bypass channel makes it possible to effectively draw off the residual air from the container. The bypass channel can be sealed after the air has been drawn off, by way of the closure element, so that no undesirable media, such as possibly non-clean ambient air, can penetrate into the container.  
         [0011]     According to a preferred embodiment of the invention, the container has a lid, for example a flange-like lid, by way of which the container is sealed with regard to the pump. In this connection, the bypass channel can be formed by an opening that runs in the lid. In this manner, the bypass channel can be provided with particularly simple means, by means of making a bore or providing a recess within the lid, for example the rigid lid. This arrangement minimizes the costs for the production of the suctioning arrangement as compared with the known configuration of the suctioning arrangement within the pump.  
         [0012]     According to a preferred embodiment of the invention, the bypass channel is formed by a valve having a valve seat, to which a valve element is assigned so that a flow out of the container into the surroundings is permitted, and blocked in the opposite flow direction. In other words, a kick-back valve can be provided in the lid or at any other desired location of the container, by means of which residual air that remains in the container when it is filled can be drawn off. At the same time, however, this valve has to prevent air from being drawn into the container during proper operation of the pump, which could result not only in the disadvantageous effects described above, but also in penetration of germs or the like.  
         [0013]     The valve of the metering pump arrangement can be configured so that, for example, an elastically deformable element is provided on the container. This elastically deformable element closes off the bypass channel, at least in one flow direction, from the surroundings into the container, in its unstressed state, and can be deformed by means of a pressure difference between the container and the surroundings, so as to permit at least a flow through the bypass channel out of the container into the surroundings. Preferably, the elastically deformable element is a strip, a disk, or the like, made of a rubber-elastic material. In particular, the elastically deformable element can be a seal ring, which is held on a tap on the outside of the container or the lid, for example, so that the seal ring closes off the bypass channel in the unstressed state.  
         [0014]     Thus, according to an embodiment of the invention, the elastically deformable material can be formed by a disk that is introduced into a depression in the lid, so that the disk is pressed into the depression along its edge and held there. An opening is provided in the center of the disk, which is closed off by means of a pin provided in the depression, which pin can be positioned offset relative to the bypass channel. If the residual air is now drawn off from the container, the disk arches away from the lid and is raised off the pin. However, the edges of the disk hold the disk in the depression, because of the tension of the disk. In this state, the residual air can escape through the opening in the disk. As soon as the pressure difference between the container and the surroundings has been reduced, the disk lies back down in the depression and the pin closes the opening of the disk. In this way, flow is prevented from the surroundings into the container.  
         [0015]     An embodiment of the invention that is simple and inexpensive to produce provides that the bypass channel can be sealed, particularly hermetically sealed, by means of a closure pin. In this connection, it has proven to be particularly advantageous if the closure pin has a closure region and a region that is profiled, for example with teeth, to form air channels. In this embodiment of the metering pump arrangement, it is possible to first insert the closure pin into the bypass channel so that air channels remain between the inner wall of the bypass channel and the region with teeth, for example, of the closure pin, so that in this position, the closure pin is securely held in the bypass channel, but at the same time, residual air can be drawn off through the bypass channel. After the air has been drawn off, the bypass channel can be sealed in that the valve pin is pressed further into the bypass channel. In this way, the closure region of the valve pin, which is not provided with teeth or a similar profiling, rests against the inner wall of the bypass channel and forms a seal.  
         [0016]     Alternatively, it is also possible to close off the bypass channel by means of gluing, bonding, sealing, or in another suitable manner.  
         [0017]     It is preferred if the pump has a pressure chamber having a piston guided in this chamber, a first kick-back valve, which connects the pressure chamber with the container, and an outlet opening that connects the pressure chamber with the surroundings and is provided with a second kick-back valve. In this connection, the first kick-back valve permits a flow out of the container into the pressure chamber, if a lower pressure prevails in the pressure chamber than in the container, while a flow in the opposite direction is essentially blocked. Accordingly, the second kick-back valve permits a flow out of the pressure chamber into the surroundings, if the pressure in the pressure chamber exceeds a defined value, while a reverse flow, for example of ambient air, into the pressure chamber is not possible because of the second kick-back valve.  
         [0018]     Instead of a pump as described that has a piston and a pressure chamber, it is also possible to provide a bellows-type pump or another suitable pump device.  
         [0019]     Since the metering pump arrangement according to the invention works without equalizing air, the container must have a changeable volume. This changeable volume is made possible, in particularly simple manner, by forming the container from a collapsible film.  
         [0020]     For easier handling of the metering pump arrangement, particularly for picking up the arrangement during activation of the pump, the container preferably has a substantially rigid covering associated with it. This covering surrounds the container and can be connected with the pump. In this connection, a ventilation opening must be provided in the rigid covering, so that collapse of the container in the covering is not hindered.  
         [0021]     As a function of the purpose of use of the metering pump arrangement, the outlet opening can be formed by a nozzle for atomizing the fluid contents of the container, for example. However, it is also possible to configure the outlet opening in another manner, for example in order to dispense individual larger droplets of a fluid by means of the metering pump arrangement.  
         [0022]     The metering pump arrangement according to the invention is particularly suitable for metering, dispensing, applying, or the like, fluid cosmetics and/or pharmaceuticals.  
         [0023]     In another aspect, a method is provided for the production of a metering pump arrangement, which comprises the following steps: First, a container is filled with a fluid product. Then the filled container, with the exception of the bypass channel, is closed off by means of the pump and/or the lid. In the next step, the residual air remaining in the container is essentially completely drawn off through the bypass channel. Upon drawing off the residual air, the bypass channel is closed off so that at least a flow from the surroundings into the container is prevented. The residual air remaining in the container when it is filled can be drawn off quickly and with simple means, in this manner.  
         [0024]     Preferably, to draw off the gas, i.e. the residual air from the container, a suction bell is set onto the metering pump arrangement, so that at least the opening of the bypass channel is surrounded by the suction bell. In this manner, the suction bell can draw the residual air out of the container through the bypass channel. Because of the pressure difference between the interior of the container and the suction bell, for example, a valve can be opened at the same time, by means of the suctioning of the residual air, which valve automatically closes again after the end of suctioning. Preferably, the valve is a seal ring that closes off the bypass channel, and the valve automatically closes because of elastic recovery forces, for example.  
         [0025]     If a punch or the like presses a closure pin into the bypass channel after the gas has been drawn off, this channel can be closed simply and in a short period of time. The filling process of the containers, which is generally automated, is thereby only minimally lengthened by drawing off the residual air and closing the bypass channel.  
         [0026]     It is preferred if the closure pin is inserted in the bypass channel with a profiled region that forms passage channels with the inner wall of the bypass channel before suctioning takes place, and after suctioning, is pressed into the bypass channel so that a closure region of the closure pin seals off the bypass channel. In this connection, the closure pin can already be held in the bypass channel so that it cannot come loose, even before the container is filled, without thereby hindering the residual air from being drawn out of the container. Closing of the bypass channel then takes place simply by pressing the closure pin further into the bypass channel.  
         [0027]     By suitable production methods, the closure pin can also be in one piece or integral with the lid and/or the bypass channel. In this way, the number of components of the metering pump arrangement according to the invention can be kept low. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]     Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.  
         [0029]     In this connection, the characteristics described and/or shown in the drawings represent embodiments of the invention, in themselves or in any desired combination, independent of how they are combined in the claims or their antecedents.  
         [0030]     In the drawings, wherein similar reference characters denote similar elements throughout the several views:  
         [0031]      FIG. 1  is a schematic sectional view of a metering pump arrangement according to a first embodiment of the invention, before the start of drawing off the residual air,  
         [0032]      FIG. 2  shows the metering pump arrangement according to  FIG. 1  after completion of drawing off the residual air,  
         [0033]      FIG. 3  is a detail of a metering pump arrangement according to a second embodiment of the invention, while the residual air is being drawn off, and  
         [0034]      FIG. 4  is a detail according to  FIG. 3 , before or after the residual air is being drawn off.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0035]     The metering pump arrangement or assembly  1  shown in  FIGS. 1 and 2  has a container  2  that can be filled with a fluid. The fluid can be, for example a liquid pharmaceutical or medical product. As shown in  FIGS. 1 and 2 , container  2 , is formed by a collapsible bag. Container  2  is connected with a pump  3 , forming a seal, which pump, in the embodiment shown, includes a pressure chamber  4  with a piston  5  that slides therein, and two kick-back valves  6  and  7 , respectively.  
         [0036]     In pressure chamber  4 , a spring  8  is provided so that piston  5  is impacted towards the top in the figure. Piston  5  has a central passage opening  9 , through which a fluid can be pumped from container  2  into the surroundings. For this purpose, the first kick-back valve  6  is switched so that first kick-back valve  6  permits a flow out of container  2  into pressure chamber  4 , if the ball-shaped valve element  6   a  is lifted from its valve seat by means of a partial vacuum in pressure chamber  4 . In the opposite direction, however, a flow from pressure chamber  4  into container  2  is blocked by first kick-back valve  6 . Furthermore, second kick-back valve  7  is disposed so that in the case of an excess pressure in pressure chamber  4 , fluid can escape through kick-back valve  7  into the surroundings. When excess pressure in pressure chamber  4  occurs, the valve body  7   a  is lifted up from its valve seat counter to the force of the valve spring  7   b . A reverse flow of ambient air into pressure chamber  4 , for example, is prevented by kick-back valve  7 .  
         [0037]     In the embodiment shown in  FIGS. 1 and 2 , container  2  is provided with a flange-like lid, for example a reinforced lid  10 , which seals pump  3  relative to container  2 . At a distance from pump  3 , an opening  11  is formed in lid  10 , into which opening a T-shaped closure pin  12  is inserted, in the embodiment shown. Opening  11  therefore forms a bypass channel by means of which container  2  is connected with the surroundings, bypassing pump  3 .  
         [0038]     Closure pin  12 , as shown in  FIGS. 1 and 2 , has a lower region  12   a  that is provided with a gear-wheel-like profiling in the form of lengthwise grooves. In this manner, closure pin  12 , together with opening  11 , forms several air channels. Through these air channels, container  2  is connected with the surroundings, in a flow connection.  
         [0039]     An upper closure region  12   b  of closure pin  12 , shown in  FIGS. 1 and 2 , has no such profiling and is provided with a diameter that at least corresponds to that of opening  11 .  
         [0040]     Furthermore, a suction bell  13  is shown in  FIGS. 1 and 2 , which can be set onto metering pump arrangement  1  so that opening  11  that forms the bypass channel is surrounded by suction bell  13 . By way of a suction line, not shown, residual air can therefore be drawn out of container  2 , by means of suction bell  13  and the air channels formed between closure pin  12  and opening  11 .  
         [0041]     Suction bell  13  is connected with an axle  15  by way of a spring mechanism  14 , by way of which a punch  16  can be activated. By lowering axle  15  with punch  16  out of the position shown in  FIG. 1 , suction bell  13  is thereby also brought to rest against lid  10  of container  2 , so that the suction bell rests on lid  10 , forming a seal. In this position, as already described, residual air can be drawn out of container  2 , through the air channels between closure pin  12  and opening  11  that forms the bypass channel.  
         [0042]     By continuously pressing down on axle  15 , punch  16  comes into contact with closure pin  12 , as shown in  FIG. 2 , and presses it further into opening  11 . As a result, closure region  12  b of closure pin  12  hermetically seals opening  11  which forms the bypass channel. In this position, air cannot enter into container  2  through opening  11  even after punch  16  is removed with suction bell  13 , and unintentional escape of fluid from container  2  is also prevented.  
         [0043]     In this state, container  2  is essentially completely filled with a fluid, for example a cosmetic or pharmaceutical product, which can be dispensed from the container by activating pump  3 . Since the residual air was drawn off from container  2 , dispensing of the product from the container is possible in any desired position of the metering pump arrangement, without the possibility of pump  3  drawing in air. Thus, eye drops or ear drops, for example, can be applied in defined amounts even in a lateral or overhead position of metering pump arrangement  1 , without air bubbles exiting from the pump.  
         [0044]     Second kick-back valve  7  can be disposed in a nozzle or another suitable dispensing device, in deviation from the embodiment shown. The device can be set into central passage opening  9  or onto the shaft of piston  5  that projects out of pressure chamber  4 . In order to prevent the penetration of germs and thereby prevent contamination of the fluid located in the pump, second valve  7  of pump  3 , in particular, can be configured differently from the embodiment shown merely as an example in  FIGS. 1 and 2 .  
         [0045]     The second embodiment shown in  FIGS. 3 and 4  differs from the embodiment described previously only with regard to the seal of bypass channel  11 . Thus, bypass channel  11  is sealed by means of an elastically deformable seal ring  17 , which is held under tension, if necessary, in a depression  18  provided in lid  10 . In this connection, seal ring  17  acts as a valve. An opening  19  is provided in seal ring  17 , which opening is closed off with a pin  20 , forming a seal, in the unstressed state shown in  FIG. 4 , which pin is disposed in the depression offset relative to bypass channel  11 . In this connection, seal ring  17  lies against bypass channel  11  so that it prevents penetration of air from the surroundings into container  2 .  
         [0046]     In contrast, seal ring  17 , as shown in  FIG. 3 , is arched up while the air is being drawn off, due to the pressure difference between the interior of container  2  and a suction bell  13 , for example, under elastic deformation. Therefore, bypass channel  11  is released. As a result, seal ring  17  also lifts up from pin  20 , in order to allow residual air to escape from container  2  through opening  19 . In this state, seal ring  17  is held in depression  18  along its edges, under bias.  
         [0047]     After the air has been drawn off, seal ring  17  lies against bypass channel  11  again, forming a seal, because of its elastic recovery force, and closes it off. At the same time, opening  19  is closed by pin  20 .  
         [0048]     Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims.