Abstract:
The invention relates to a self-closing valve for dispensing a free-flowing product. The valve has a valve membrane with an opening for dispensing and an encircling edge at the outer perimeter, wherein the valve membrane is able to switch between a closed mode, a dispensing mode, and a back suction mode due to pressure differences produced. There is also a stopper on which the valve membrane lies in the closed mode and in the back suction mode so that the dispensing opening is closed, and from which it is lifted in the dispensing mode. The valve includes a stop ring, on which the encircling edge of the valve membrane lies as a seal during the closed mode and from which it is lifted in the back suction mode, and a lateral channel that extends axially, wherein at least parts of the encircling edge are opposite the valve membrane, and the encircling edge is movable axially on the lateral channel to switch to back suction mode, in which a gap is created between the encircling edge and the lateral channel.

Description:
BACKGROUND 
       [0001]    The present invention concerns a self-closing valve for the dispensing of a free-flowing product. 
         [0002]    A typical application for self-closing valves are containers in which the dispensing of a free-flowing contents occurs by squeezing the container. One example of this are so-called squeeze bottles for skin care products. Thanks to the reduction of the inner volume of the bottle when it is squeezed by the user, the pressure inside it increases, so that the contents, such as a liquid soap, are dispensed through the valve. Thanks to the self-closing action of the valve, the contents are prevented from escaping unintentionally without this pressure increase, even when the container is not closed with a cap and even when the product bears by its gravity against the dispensing zone of the valve. 
         [0003]    A self-closing valve for the dispensing of a liquid or pastelike product is known from DE 102 18 363 A1. The valve includes a valve membrane, which is shaped convex in the direction of the product. The valve membrane is formed with a support ring at the margin, shaped by extrusion. For a proper dispensing of the product, the valve membrane is underpinned by a plate part. The plate part, in turn, is supported by spring arms, which causes increased construction expense for the valve. Another drawback of this solution is that the plate part in particular obstructs the air equalization, so that the container has to exert a large restoring force. 
         [0004]    A self-closing valve with a closure membrane for dispensing a fluid filling in a compressible container is known from DE 196 13 130 A1. In the nonactivated installed condition, the closure membrane has a lower support edge and an upper closure cover extending concavely basically in the dispensing direction. In a normal dispensing process, opening slits in the closure membrane open up reliably and almost abruptly at a certain pressure. When the dispensing is completed, the container is restored, so that the closure membrane is pulled back into the concave starting condition. The opening slits are now broken through toward the inside, so that air is sucked back in. In order to improve this suction, grooves can be introduced between the closure membrane and its support. The drawbacks of this solution are the limited tightness and the large partial vacuum needed for the back suctioning. In order to achieve a large back suction effect, the containers have to be configured with corresponding spring action. This necessitates a high input of material for the container, so that the manufacturing costs are increased. 
         [0005]    A self-closing valve with a plate-shaped valve membrane is known from EP 0 388 828 A1. The valve membrane has a central dispensing opening, which is placed on a support plate and thereby sealed off. This solution has no possibility of back suctioning of air. 
         [0006]    A self-closing closure for a container or a tube is known from DE 43 29 808 C2, in which an outlet opening in a closure cover is closed by a closure pin. When the pressure increases, the closure pin is supposed to move inwardly, so that the outlet opening is opened up and the product can escape through the outlet opening. For this, however, the air in a closed cavity beneath the closure pin has to be compressed, since it cannot get to the outside. Consequently, a very large pressure is needed for the closure pin to free up the outlet opening, so that this valve has few applications. Furthermore, this solution has no possibility of back suctioning of air, so that it any case it would only be suitable for certain products. 
         [0007]    A self-closing valve with an inwardly cambered valve membrane is known from DE 195 80 254 B4. The valve membrane, in turn, has a central dispensing opening, which is placed on a support plate and thereby sealed off The valve membrane is supported at the top by a support flange, against which the valve membrane thrusts from the bottom in a radially outward bearing zone. A pin can be configured on the support plate, which travels into the dispensing opening in the closed position and thus enables a reliable seal. The lateral bearing region of the valve membrane can be configured so that it is deformed inwardly when the pressure is low, thereby freeing up an air pathway for the back suction. However, such a deformation requires a large partial vacuum, so that the wall of the container has to exert correspondingly large restoring forces. 
         [0008]    Thus, the problem of the present invention is to provide a self-closing valve for the dispensing of a free-flowing product, which is very simple and economical to produce and requires only a slight low pressure for the back suction of air. Furthermore, a good sealing effect of the valve is desired, in order to reliably prevent unintentional escaping of even slight amounts of the free-flowing product. 
       SUMMARY 
       [0009]    This problem is solved by a self-closing valve according to the enclosed claim  1 . In the self-closing valve, a valve membrane for the dispensing of the product switches from a closing position to a dispensing position. In the closing position, a dispensing opening of the valve membrane is closed by a stopper. In the dispensing position, the dispensing opening is lifted from the stopper and freed up. The outer periphery of the valve membrane forms an encircling edge, which lies tight against a stop ring in the dispensing position. Between the encircling edge and a lateral guide is formed a gap, through which air can be sucked back in upon relaxation of the container closed by the valve. 
         [0010]    A special benefit of this invention consists in that a very simplified construction and a distinctly improved back suction of air can be achieved at the same time. The valve membrane can be formed by a simple plastic disk, which can be produced very economically. A container with a valve according to the invention need not have very great restoring forces. Consequently, the wall of the container can be thin, so that the use of the invented valve enables a material-sparing and low-cost production of the container. 
         [0011]    Further benefits, details, and modifications of the invention will appear from the following descriptions of several embodiments, making reference to the drawings. These show: 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0012]      FIG. 1 : cross sectional representations of a self-closing valve per the invention in four phases during the transition to a dispensing mode; 
           [0013]      FIG. 2 : cross sectional representations of the valve shown in  FIG. 1  in three phases during a back suctioning of air; 
           [0014]      FIG. 3 : a perspective view of a fastening frame with wedge-shaped support webs; 
           [0015]      FIG. 4 : a perspective view of a modified fastening frame with support pins; 
           [0016]      FIG. 5 : a perspective detailed view of a stiffened embodiment of a valve membrane; 
           [0017]      FIG. 6 : a perspective detail view of a modified embodiment of the valve membrane. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1  shows a cross sectional representation of a preferred embodiment of an invented self-closing valve  01  in four phases during the transition from a closed position to a dispensing position. Figure a) of  FIG. 1  shows the valve  01  in the closed position. Figures b) and c) of  FIG. 1  show the transition to the dispensing position and figure d) of  FIG. 1  shows the valve  01  in the dispensing position. It should be noted in general for an understanding of the figures that the valve is configured for installation on a container (not shown), for example, by being inserted into the neck of a squeeze bottle. 
         [0019]    The valve  01  includes a round circular valve membrane  02  with a round circular dispensing opening  03  in its center. The valve membrane  02  basically has the shape of a disk spring and also exhibits comparable spring properties. In  FIG. 1 , a), the valve membrane  02  is shown in a position when the valve  01  is closed. In this closed position, the valve membrane  02  lies with its dispensing opening  03  against a stop disk  04 . A round bearing surface  06  formed in this way on the stop disk  04  closes the dispensing opening  03 . Furthermore, a sealing lip  07  of the valve membrane  02  lies with play against a pin  08  of the stop disk  04 , as the pin  08  projects into the dispensing opening  03 . The envelope surface of the pin  08  has the shape of a truncated cone and corresponds in a guiding region  09  to the inner surface of the sealing lip  07 . The shape of the valve membrane  02  is inwardly cambered in the closing position shown and has the shape of a truncated conical envelope surface, except for the sealing lip  07 . 
         [0020]    The valve membrane  02  is elastically deformable, while the truncated cone shape and the sealing lip  07  impose a pretensioning, which dictates the deformability. The outer circumference of the valve membrane  02  is formed by an encircling edge  11 . The encircling edge  11  lies, in the closed position (Fig. a), against a stop ring  12 . The valve membrane  02  is supported on top by the stop ring  12 . A lateral movement of the valve membrane  02  is limited by a lateral guide  13 . In the embodiment shown, the stop ring  12  and the lateral guide pass one into the other as a single piece, which allows for an easy fabrication. But the stop ring  12  and the lateral guide  13  can also be made as two pieces. In the embodiment shown, the lateral guide  13  and the stop disk  04  are designed as two pieces. But the lateral guide  13  and the stop disk  04  can also pass one into the other as a single piece. The lateral guide  13  is round and circular in the embodiment shown. But the lateral guide can also be designed so that it guides the valve membrane  02  only at several points or segments on the circumference. In the embodiment shown, the stop ring  12  has a slanting cross sectional surface. But the stop ring  12  can also be designed perpendicular to the lateral guide  13 . The encircling edge  11  of the valve membrane  02  lies beneath the stop ring  12 , so that the valve membrane  02  is sealed off from the stop ring  12 . Through openings  14  in the stop disk  04 , the product kept inside the container (not shown) or air can flow in the direction  16  into the region beneath the valve membrane  02 . 
         [0021]    The encircling edge  11  of the valve membrane  02  preferably has the same material thickness as the main part of the valve membrane  02 . The encircling edge  11  is not reinforced and has no particular shape, such as additional sealing lips. The encircling edge  11  of the valve membrane  02  at the same time serves as the upper and lateral stop for the valve membrane  02 . Between the lateral guide  13  and the encircling edge  11  of the valve membrane  02  there is formed a gap  15 . The gap  15  runs peripherally in the embodiment shown. In other embodiments, the gap can be in segments, for example, if the valve membrane  02  is guided laterally at only a few points. 
         [0022]    The self-closing valve  01  is especially suitable for so-called squeeze bottles in which a manual squeezing of the bottle dispenses the free-flowing product. For this, the valve  01  is arranged in the opening of the bottle provided for the dispensing. The embodiment of the invented valve shown in  FIG. 1  has a circular fastening frame  21  for this, which can be inserted into the opening of the bottle. But the invented valve can also be designed as an integral part of the container. 
         [0023]    In figure b) of  FIG. 1 , the valve  01  is depicted in a condition when the pressure inside the container has been slightly increased. This occurs, for example, when the manual squeezing process is begun to dispense a product from a squeeze bottle. But a slightly increased pressure can also occur when a force is exerted on the bottle by handling it, without a dispensing of the product being intended. Due to the slightly increased internal pressure, a force acts in direction  16  on the valve membrane  02 . This will slightly deform the valve membrane  02 . Due to the deformation of the valve membrane  02 , the sealing lip  07  is wedged with the truncated cone-shaped pin  08  in the guiding region  09 , so that a secure seal is assured between the pin  08  and the sealing lip  07 . At the same time, the deformation of the valve membrane  02  increases the bearing force of the valve membrane  02  against the stop ring  12 , which intensifies the sealing action of the valve membrane  02  against the stop ring  12 . Thus, the invented valve  01  has the advantage that slight pressure increases do not result in dispensing of the product. For example, during the opening or closing of a squeeze bottle with a cap, one will firmly grasp the squeeze bottle. This will slightly increase the internal pressure in the bottle, but no release of the product is intended. Furthermore, the initial deformation of the valve membrane increases the seal of the valve membrane  02  against the pin  08 , since the sealing lip  07  is pressed more strongly against the pin  08 . The deformation of the valve membrane  02  enlarges its cross sectional dimension, so that there is still retained a sealing abutment against the pin  08 . Therefore, if the pressure increase is only slight, the seal remains preserved in the central region of the valve membrane  02 , even if the membrane should lift off from the bearing surface  06 . 
         [0024]    Figure c) of  FIG. 1  shows the valve  01  with further increased internal pressure in the container. The valve  01  is just about to switch from the closed position to the dispensing position. The increased internal pressure has the effect of deforming the valve membrane  02  so that the truncated cone shape is distinctly flattened. This is especially due to the fact that, because of the increased internal pressure, a force acts in the direction  17  on the valve membrane  02  beneath the sealing lip  07 , which distinctly raises the valve membrane  02  in this region. But the pin  08  is still sealed off against the sealing lip  07 . 
         [0025]    Figure d) of  FIG. 1  shows the valve  01  when the internal pressure has become so large that the valve  01  has switched to the dispensing position. The valve membrane  02 , except for the sealing lip  07 , has reached a nearly flat shape. In the embodiment shown, it has the shape of a very flat truncated cone, and this truncated cone is directed opposite the truncated cone shape in the closed position. The valve  01  can also be designed so that the valve membrane  02  in the dispensing position has a truncated cone shape opposite the truncated cone shape of the closed position, but with a distinctly smaller inclination. When the valve membrane  02  switches from the closed position to the dispensing position, the valve membrane  02  is thus turned inside out. The configuration of the valve membrane  02  has the effect that a maximum force acting on the valve membrane  02  has to be overcome for this to occur. The user can both hear and feel when the maximum force is exceeded and the membrane is turned inside out. This improves the consumer qualities, especially the tactile handling of the squeeze bottle outfitted with the invented valve  01 . As soon as the valve membrane has changed to the inverted truncated cone, it stays in this shape, even when the force acting on it lessens once again. If the force drops below a certain threshold value, the valve membrane  02  suddenly changes back to the truncated cone of the closed position. This provides a definite closing moment, resulting in a clean cut-off of the stream of expressed liquid, so that further dripping is largely avoided. 
         [0026]    In the dispensing position shown in Fig. d), the sealing lip  07  is distinctly lifted relative to the pin  08 , so that a large opening has formed between the sealing lip  07  and the pin  08 . The product is released through the openings  14  in the stop disk  04  and through the dispensing opening  03 . A directional arrow  18  illustrates the direction of flow of the product. The diameter of the pin  08  determines the diameter of the dispensing opening  03  and thus the amount and rate of flow of the product. 
         [0027]    In the embodiment shown, the switching from the closed position to the dispensing position is sudden. This has the result that a squeeze bottle with such a valve  01  relaxes suddenly during this process as soon as the excess pressure produced by the squeezing has dissipated. At this moment, a determined amount of product will be released. The valve  01  and the squeeze bottle can be dimensioned so that the suddenly released amount of product corresponds to the typical amount of consumption of the product. Thus, the user can intuitively dispense the typical consumption amount of product. If a larger amount is desired, then the bottle should be squeezed further after the sudden switching of the valve  01  to the dispensing position. Since the maximum force for the switching to the dispensing position has already been overcome, little effort is needed to put out larger amounts of the product. 
         [0028]      FIG. 2  shows cross sectional representations of the self-closing valve  01  shown in  FIG. 1  in three phases during the transition from the closed position to a back suction position.  FIG. 2  a) shows the valve  01  in the closed position.  FIG. 2  b) shows the transition to the back suction position and  FIG. 2  c) shows the valve  01  in the back suction position. 
         [0029]    The closed position shown in  FIG. 2  a) occurs after the dispensing of the product is finished. In this condition, the increased internal pressure is dissipated by the dispensing of the product. The valve membrane  02  has again taken up its starting shape and position. This occurs, for example, when the user has stopped applying force to squeeze the bottle so that no more product comes out, but the force is still large enough for the deformation of the bottle to remain in place. In this condition, the volume of the bottle is smaller than the volume of the nondeformed bottle. If the force to deform the bottle is entirely halted, the elastic restoring forces of the wall will act. Since the volume of the bottle is reduced during moment, a low pressure is formed in the bottle. 
         [0030]    In  FIG. 2  b), a first action of the low pressure is shown. Since the valve membrane  02  is still sealed off against the bearing surface  06  on the stop disk  04  and against the stop ring  12 , the low pressure cannot yet be equalized by incoming air and a slight deformation of the valve membrane  02  will result. The valve membrane  02  therefore has a very slight inward camber. This camber will not become larger as the low pressure increases, since the peripheral margin region of the valve membrane  02  will yield to the internal pressure. 
         [0031]      FIG. 2  c) shows the valve  01  after the peripheral margin region of the valve membrane  02  has yielded to the low pressure on the inside. Since the peripheral margin region of the valve membrane  02  is not supported and not reinforced by a stiffening or similar configuration, it only needs a very slight force for this. Consequently, a back suctioning of air by the invented valve  01  is already possible with a very slight low pressure. In this back suction position, the valve membrane  02  is lifted from the stop ring  12 , so that it is no longer sealed off against the stop ring  12 . Consequently, air from the outside can flow in through the created opening. This air flow is not hindered, because the peripheral gap  15  is formed between the valve membrane  02  and the lateral guide  13 . The air can flow in from the outside practically unhindered and dissipate the low pressure prevailing there. A directional arrow  19  illustrates the air flow. As soon as the low pressure is totally dissipated, the squeeze bottle is once again in its starting shape. The peripheral gap  15  also guarantees a sufficient back suction of air when segments of the gap  15  are still closed by remaining portions of the product being dispensed. Yet even these portions of product are sucked back into the interior of the bottle by the effect of the back suction. This likewise holds for portions of product left behind on the outside of the valve membrane  02 , since there as well a back suction effect is at work. 
         [0032]    The invented valve in the embodiment presented more closely above consists of only two parts. This enables a simple and fast assembly, since only the valve membrane needs to be forced into the fastening frame with a stamp. The membrane can preferably consist of silicone or a comparable soft elastic plastic, while the fastening frame can be made as an injection molded part from a more stiff plastic. 
         [0033]      FIG. 3  shows a perspective view of a modified embodiment of the fastening frame  21 . For better visibility of the details of the fastening frame, the valve membrane is not shown. Several support webs  22  are secured to the stop disk  04 , extending radially in the embodiment shown here from the centrally arranged pin  08  to the inside of the fastening frame  21 . These support webs  22  serve primarily to stabilize the position of the valve membrane, which in the closed position of the valve lies by segments on the support webs  22 . Furthermore, the support webs  22  enhance the stability of the overall valve arrangement. 
         [0034]      FIG. 4  shows a perspective view of a modified embodiment of the fastening frame  21 . The essential difference from the embodiment shown in  FIG. 3  consists in that several support pins  23  are used in place of the support webs, being secured to the stop disk  04 . The support pins  23  fulfill the same function as the previously mentioned support webs, namely, the stabilization of the position of the valve membrane in the closed position of the valve. Of course, other profiling can also be provided within the fastening frame in order to control the position of the valve membrane and support it during the closed condition. Different numbers of support points will be provided for this, depending on the embodiment and the natural rigidity of the valve membrane. 
         [0035]    The fastening frame, including the lateral guide and the stop disk, can also be configured in a modified embodiment as a single piece with the squeeze bottle or a similar container. 
         [0036]      FIG. 5  shows a perspective detail view of a modified embodiment of the valve membrane  02 . For certain substances/media which are meant to be dispensed from a storage container via the self-closing valve, it is advantageous to be able to adapt the stiffness of the valve membrane and/or the nature of the deformation upon opening of the valve. For this, stiffening means  24  are provided in the surface region of the valve membrane  02 , for example, extending radially and distributed uniformly at the periphery of the valve membrane. In modified embodiments, one can also provide for weakening of the material in order to favor a deformation of the membrane at the corresponding places. 
         [0037]      FIG. 6  shows in a perspective detail view another possible modification of the valve membrane  02 . Here, contouring means  25  are provided in the region of the dispensing opening  03 , which project into the otherwise open cross section of the dispensing opening  03  or are provided in the wall in the region of the dispensing opening  03 . When a medium is dispensed through the self-closing valve, the contouring means  25  produce a strand of material. Different numbers and shapes of contouring means can be provided. Preferably, the contouring means  25  are located at the outer edge of the dispensing opening  03  in the direction of flow. In modified embodiments, however, the contouring means can also be moved further inward in the direction of flow, for example, by profiling or slitting the wall in segments. Such a slitting, furthermore, offers the advantage that the transition of the membrane from the closed position to the dispensing position is facilitated, since no change in cross section can occur in the marginal region of the dispensing opening  03 . 
         [0038]    Advisedly, the valve will be covered by a cap when not in use, being placed in familiar fashion on the squeeze bottle.