One-way valve for a deformable container

Abstract: The one-way valve for a container supplying a liquid under pressure by means of compression of the container is designed to be inserted between the outlet mouth (12) of the container (10) and the end (17) of the supply nozzle (14) connected thereto. Said valve comprises a hollow body (18) inserted partially into the outlet mouth (12) of the container (10), the base of which engaging with said end (17) of the nozzle (14) is open, while the other base (22) has an essentially central hole (24) through which the liquid passes. Said hollow body (18) accomodates internally an obturator member (26) essentially consisting of a shaped stopper (28) connected, via elastically deformable lugs (34), to its support element (32) inserted inside the hollow body (18) and having a longitudinal passage (40) with a cross-section greater than that of the stopper (28). The lugs (34) are designed to keep the stopper (28) engaged in the hole (24) of the hollow body (18) when the container (10) is not compressed and to allow it to be moved away from said hole (24) when the container (10) is compressed in order to supply the liquid.

Description: The present invention relates to a valve for liquids suitable for application to flexible bottles or containers, the contents of which are designed to be supplied by means of manual pressure, having the dual function of: a) moderating the speed of flow; b) preventing backflow. An area in which the valve in question finds widespread use is for example the pharmaceutical sector where it is extremely important that a container with a liquid used for irrigation or medical purposes, when the latter is administered, should exclusively allow the said liquid to flow out from the container and prevent it from flowing back into the container for obvious hygiene/sanitary reasons. The containers in question are therefore provided with a unidirectional valve which has the function of performing the above task. A typical example of a container where it is essential that the aforementioned valve be provided is a container such as a rubber syringe used for intestinal enemas or irrigations. In this area of use, it is necessary to moderate the force of flow of the liquid supplied, which could result in local pain, cramps and the risk of tearing the mucous tissue. Containers of the type in question are known and it is also known that they are generally of the disposable type (see e.g. US-A-3 165 242). The abovementioned containers are provided, internally at the end of the supply nozzle which is connected to the actual container, with a unidirectional valve which essentially consists of thin small disc, generally made of rubber and with a thickness of about 1 mm, which has formed in it a substantially diametral incision, the edges of which move apart under the effect of the pressure of the liquid inside the container, a pressure which is generated by the compressive action exerted on the said container made of deformable material. The liquid is therefore able to flow out from the container and the supply stops each time compression of the container is interrupted. The known valves of this type have not insignificant drawbacks which are linked mainly to the fact that the disc is an extremely delicate component and this negative characteristic must be taken into account both as regards its manufacture and as regards the difficulties which are encountered when carrying out the preliminary treatment which the disc must undergo before being fitted on the container, such as washing and sterilisation for example. A further drawback arises from the fact that the disc must have extremely precise dimensions so as to ensure a perfect seal in particular along its edge in order to prevent the undesired seepage of liquid between the latter and the cap for closing the container. Ensuring a uniform thickness of the rubber sheet form which these discs are made, which should remain around one millimetre, represents an unresolved problem. This has meant that it has been necessary to use discs with thicknesses varying from 0.8 to 1.5 mm, thus frequently resulting in a poor sealing action of the closing caps inside which the discs are fitted. Another not insignificant drawback lies in the fact that fitting the disc requires long and costly manual operations, not to mention the additional operational difficulties of ensuring conditions of absolute hygiene for the manual operations. A one-way valve has now been conceived and constitutes the object of the present invention, suitable for use in particular in a container supplying a liquid by means of manual pressure, which is capable of overcoming all the drawbacks arising from the use of rubber discs and the use of components of conventional valves having imprecise dimensions. It is therefore one of the aims of the present invention to provide a valve of the type in question which has precise dimensional uniformity as well as structural characteristics and a strength such that it may be easily assembled before being fitted, with no costly problems of a technical and hygienic nature. Another aim of the present invention is to provide a valve which is extremely simple to realize and may therefore be manufactured in considerable quantities and with limited costs. It will become clear below that this valve may be obtained by means of simple injection-moulding. A further aim of the invention is to provide a valve which may be fitted without manual operations and hence in a completely automatic manner, thereby achieving a high level of productivity and eliminating the problems of hygiene. The subject of the present invention, therefore, is a one-way valve for a container supplying a liquid under pressure by means of manual compression of the container, as defined in claim 1. Particular embodiments of the one-way valve defined in claim 1 are specified in the dependent claims. An embodiment of the valve according to the present invention will emerge more clearly from the following detailed description thereof and the accompanying figures, in which: Figure 1 is a partially sectioned, exploded view of the valve with the container partly shown; Figure 2 is a partially sectioned side view of the valve in the closed or rest condition; Figure 3 is a sectioned side view of the valve in the open or working condition, and Figure 4 is a view, on a larger scale, of the valve along the section IV-IV of Figure 3. With reference to the abovementioned figures, the valve according to the present invention applied, purely by way of example, to a container for intestinal enemas or irrigations will now be described, it being possible for to extend the use of said valve to other types of container without any modification. The reference numeral 10 denotes a container for a liquid, for example of a medicinal nature, made of deformable plastic material and therefore suitable for supplying a liquid under pressure by means of compression of the said container. A supply nozzle 14, onto which a protective cap 16 is fitted, is fixed onto the outlet mouth 12 of the liquid from the container 10. Securing of the nozzle 14 on the outlet mouth 12 is effected by means of snap engagement and for this purpose the outlet mouth 12 is provided with external peripheral ribs 13 designed to be coupled with corresponding internal recesses 15 proveded in the end 17 of the nozzle 14 which is fitted onto said outlet mouth 12. In particular, it will be noted that the actual nozzle 14 and its end 17 are made as a single piece. A cylindrical hollow body 18 is inserted into the abovementioned outlet mouth 12, the base of which body directed towards the nozzle 14 is open and has an external radial edge 20 with which the hollow body 18 rests on the edge of said outlet mouth 12 without projecting therefrom. When the nozzle 14 is fitted onto the container 10, it engages with the abovementioned edge 20, securing it around the periphery of the outlet mouth 12 and this engagement also produces a sealing effect which prevents liquid form passing outside the hollow body 18, allowing the liquid to pass only inside it, as will emerge more clearly below. The other base 22 of the hollow body 18 is provided with an essentially central hole 24 through which, once the valve is open, the liquid flows from the container 10 to the nozzle 14. The hollow body 18 accommodates internally an obturator member, denoted in its entirety by the reference number 26, which comprises a shaped stopper 28 intended to engage with the hole 24 as illustrated in Figure 2, for closing of the valve, or to disengage from the abovementioned hole, for opening of the said valve, as will be explained below. As can be seen in particular in Figures 1 to 3, the hole 24 is flared with a frustoconical cross-section diverging in the direction of the stopper 28, the latter having a generally cylindrical shape correspondingly tapered in the direction of the hole 24 so as to ensure at all times correct engagement of the stopper 28 in the hole 24 and proper sealing of the valve in the closed condition. Again in particular from Figures 1 to 3 it can be seen that the stopper 28 is hollow and its closed base 30, located opposite the nozzle 14, is curved outwards. This arrangement ensures a greater area of contact between the stopper 28 and the liquid under pressure, increasing the thrusting force on the said stopper and ensuring that it is moved away from the hole 24 in a more secure and stable manner. The stopper 28 is connected to its support element 32, described below, by means of a group of three elastically deformable lugs 34, each consisting of a thin plastic fillet, the elasticity of which is such as to allow the stopper 28 to move from the position shown in Figure 2 (valve closed) to that shown in Figure 3 (valve open) under the action of the pressurised fluid when the container 10 is compressed and back into the position of Figure 2 when said compressive action is ceased. According to one of the characteristic features of the valve according to the invention, the lugs 34 have the same length and are inclined at the same angle with respect to the longitudinal axis of the obturator 26, for example at an angle of 120 o , so as to facilitate movement of the stopper 28 and require a smaller thrusting force for opening of the valve. Moreover, the stopper 28 is located in an essentially central position and its longitudinal axis coincides with that of the hole 24. As can be further seen from Figures 1 and 2, the lugs 34 are all inclined in the same manner and this arrangement has been realised to ensure that the movement of the stopper 28, both during opening of the valve and during closure, is always rectilinear, this assuring, among other things, that the stopper 28 engages correctly inside the hole 24. It must be remembered that the positive effects of the arrangement now described are in addition to the abovementioned advantages arising from the shape of the stopper 28 and the hole 24. From figure 4, also, it can be seen in particular that, in the open condition of the valve, the lugs 34 are deformed in spiral arcs oriented in the same direction and having the same length so as to further ensure the rectilinear movement of the stopper 28. The support element 32 of the stopper 28 has a generally cylindrical shape and at the top has an external peripheral edge 36 which is inserted into a corresponding seat 38 of the hollow body 18 and, like the latter, is kept in position by application of the nozzle 14, as can be seen from Figures 2 and 3. The support element 32, finally, has a longitudinal passage 40 with a cross-section greater than that of the stopper 28 precisely so as to allow the liquid to flow through in the direction of the arrow F in Figure 3, when the valve is open. As regards the materials from which the valve is made, these may consist of polyethylene as regards the hollow body 18 and ethylene vinyl acetate as regards the obturator 26. As a result of this, it is possible to achieve the dual advantage of being able to manufacture the two components by means of simple injection moulding and of being able to assemble them automatically without manual operations. The valve furthermore is particularly robust as well as being stable and reliable during operation.

Claims: One-way valve for a container supplying a liquid under pressure by means of compression of the container, designed to be inserted between the outlet mouth of the container and the end of the supply nozzle connected thereto, wherein it comprises a hollow body (18) inserted partially into the outlet mouth (12) of the container (10), the base of which engaging with said end (17) of the nozzle (14) is open, while the other base (22) has a central hole (24) with a crossection smaller than that of the base which engages with the end of the nozzle through which the liquid passes, said hollow body (18) accommodating internally an obturator member (26) essentially consisting of a shaped stopper (28) connected, via elastically deformable lugs (34), to its support element (32) inserted inside said hollow body (18) and having a cylindrical outer shape and a longitudinal passage (40) with a cross-section greater than that of said stopper (28), said lugs (34) being designed to keep said stopper (28) engaged inside the hole (24) of the hollow body (18) when the container (10) is not compressed and to allow it to be moved away from said hole (24) when the container (10) is compressed in order to supply the liquid. Valve according to claim 1, characterized in that said lugs (34) are inclined with respect to the longitudinal axis of said obturator member (26). Valve according to claim 2, characterized in that said lugs (34) have the same length and are inclined at the same angle in the same direction with respect to the longitudinal axis of said obturator member (26) with respect to which said stopper (28) is therefore in an essentially central position and its longitudinal axis coincides substantially with that of said hole (24), movement of the stopper (28) during opening and closing of the valve occurring along a substantially rectilinear path coinciding with said longitudinal axis. Valve according to claim 1, characterized in that said stopper (28) is hollow and its closed base (30), located opposite the nozzle (14) is curved outwards. Valve according to claim 1, characterized in that said hole (24) is flared with a frustoconical cross-section diverging in the direction of the stopper (28) which has a generally cylindrical shape correspondingly tapered in the direction of the hole (24). Valve according to claim 1, characterized in that securing of the nozzle (14) onto the outlet mouth (12) is effected by means of snap-engagement, the outlet mouth (12) being provided with external peripheral ribs (13) designed to be coupled with corresponding internal recesses (15) provided in the end (17) of the nozzle (14) which is fitted onto said outlet mouth (12). Valve according to claim 6, characterized in that the actual nozzle (14) and its end (17) which is fitted onto said outlet mouth (12) of the container (10) are made as one piece. Valve according to claim 1, characterized in that said hollow body (18) and said support elements (32), both with a generally cylindrical shape, have at the top an external radial edge, (20) and (36) respectively, the former of which engages with the peripheral edge of said outlet mouth (12) of the container (10), while the latter is inserted into a corresponding seat (38) of the hollow body (18), both said edges (20,36) being kept in position by application of the nozzle (14) onto said outlet mouth (12) of the container (10)

Inventors: LABRUZZO CARLA, LABRUZZO, CARLA
Applicants: SOFAR SPA, SOFAR S.P.A.
Application year: 1992
Main classification: B65D35
IPC codes: B05B11, B65D47