A DEVICE FOR DISCHARGING FLUID AND A METHOD FOR PRODUCING SUCH DEVICE

Abstract: A device for discharging fluid from a container (1) comprises a metering device in the shape of a tubular, thin-walled and compressible outer portion (14) and a relatively rigid, tubular inner portion (10) which latter communicates with the interior of the container (1) and in which there is provided a return valve (12) which permits fluid to pass from the container into the inner portion but not in the opposite direction. The tubular outer portion (14) is terminated by a return valve (15) which opens in response to a pre-determined pressure upon the fluid enclosed in the metering device. The inner tubular portion further has a slot (11) which extends from the free end of the inner portion up to the vicinity of the opposite end thereof and above the end of the slot there is in the metering chamber a space in which air drawn out in connection with the filling of the metering device may be cumulated and compressed to exert a buffer action. The invention further refers to a method for making the device according to which at least the inner portion (10) and the tongue (12) are made in one piece and with such wall thicknesses and configurations that a sufficient sealing between the inner portion and the tongue is obtained by means of the shrinkage of the material.

Description: A DEVICE FOR DISCHARGING FLUID AND A METHOD FOR PRODUCING SUCH DEVICE The present invention refers to a device for discharging fluid from a container and a method for producing the device. In the US patent .2^9-675 a device for discharging fluid from a con- tainer is described which comprises a flexible metering chamber which is connected to said container and communicates with the container and at the lower portion thereof terminates in a self-closing membrane valve provided to open at a pre-determined pressure upon the contained fluid. In the upper end thereof the metering chamber has a seat for a float valve housed in the metering chamber, said float valve due to the buoy¬ ancy thereof normally being in contact with said seat, thereby keeping the contained fluid separated from the fluid in the- container. By grasp¬ ing the metering chamber with the hand and compressing it a metered dis¬ charge takes place which as to the amount depends upon said compression. When the pressure ceases the metering chamber takes its initial shape and by means of the vacuum resulting therefrom the float valve opens and fluid is sucked into the metering chamber. The float valve has an elong¬ ated shape and also serves the purpose of limiting said compression. A device of that character has proven to operate well when the contained fluid has a relatively high viscosity but not so well when thick creams or the like are to be expelled. Another disadvantage is that the metering chamber needs to be vertically disposed to enable the float valve to operate properly. Thus- the main object of the invention has been to provide a device for discharging fluid which in contradistinction to the known device may be successfully used for media with high viscosity as well as for media with low viscosity, which needs no particular orientation of the metering chamber and which may be produced at a low cost due to the fact that it comprises a few, easy-to-manufacture parts. To accomplish this and further objects the invention has the character¬ istics of the patent claims. The accompanying drawing illustrates an exemplary embodiment of the in¬ vention. In the drawing Fig. 1 is a section through the new device, connected to a container, Fig. 2 is a partial section on a larger scale through an upper part of the device. Fig. 3 shows ' in a view taken obliquely from below a tongue forming part of the device and adjacent parts of a wall cooperating with said tongue. Fig. 4 finally, shows a detail of fig. 2 on a larger scale. In the drawing numeral 1 generally designates a container from which only a lower portion is shown. The container may have any suitable shape and it may be in the form of a rigid container, a bag, a tube container or the like. In the illustrated embodiment the container in the lower por¬ tion thereof has a connection piece 2, which preferably has a pair of circumferential grooves and the container further has a planar under sur¬ face. The metering chamber which in the drawing has the general designation and which is manufactured from a material with elastically deformable characteristics has a metering chamber denoted as 5 and has a connection portion 6 which in the upper end surface thereof has annular profiled grooves 7 which are complementary to the connection piece 2 of the con¬ tainer with the grooves thereof. The design is such that the metering device may be connected to the container 1 in that the connection piece of the former is snapped into the grooves 7 of the latter. Alternatively or additionally the sealing connection which is aimed at may be accomp¬ lished by means of so called plastics welding and to this end the connec¬ tion portion 6 has a planar annular flange 8 for cooperation with the planar portion 3 of the container.". By means of an annular wall 9 the connection portion 6 is connected to a tubular portion 10, downwardly directed as seen in fig. 1. In this tubuilar portion 10 there is for a reason to be explained, provided a through, relatively narrow slot 11, which extends almost up to the upper end of the tubular portion 10. Integral with the portion 10 and extend¬ ing from the relatively thick wall portion 9 there is formed an obliquely extending tongue 12, which as will appear from the following acts as a return valve and closes respectively opens the communication between the interior of the tubular portion 10 and a recess 13, which consti- tutes the upper mouth of th'e metering device and which is in direct communication with the interior of the container. Further extending from the connection portion 6 in a downwards direction there is a thin-walled tubular portion 14 which in the lower free end thereof has a self-closing closure 15 capable of opening in response to a specific pressure in the metering chamber. In the illustrated embodiment the metering chamber 5 with the connection portion 6 thereof, the inner portion thereof and the outer tubular por¬ tion ι k thereof as well as the tongue 12 is made in one single piece and as appears from fig. 2 and fig. 4 the tongue 12 is thin-walled and has an elliptical shape. The upper portion 17 of the tongue is in one piece with the wall 9 which according to the illustrated embodiment constitutes the upper part of the inner portion 10. In the injection moulding there is generated between the tongue 12 and the interior of the inner portion 10 a slit 16 (see fig. 3) which follows the contour of the tongue. The injection mould may have cores directed towards each other and con¬ tacting each other in a narrow edge zone and this edge zone in fact con¬ stitutes the narrow slit. If the wall portion 9 and the inner portion 10 has a wall-thickness which is considerably greater than the wall thickness of the tongue 12 there wϊ 11 be a different shrinkage in the tongue and the immediate vicinity thereof when the plastic material solidifies and by arranging these cum¬ ulations of material in a suitable manner it has been possible to obtain the effect that the slit 16 which is inevitable will be eliminated there¬ in that the tongue in spite of this original slit will after the manu- facturing seal against the inner wall of the inner portion and it is thus seen that in this manner there has been provided a simple and in¬ expensive return valve. If the plastics material consists of polypropene it has been found that the desired effect will be attained when the wall portion 9 will have a thickness which should be 4-5 timed the thickness of the tongue 12 but which may be within the interval! of 3-6 times. The wal l thickness of the tongue should be 0,2-0,6 mm and preferably 0,4-0,5 mm. The device now described is prepared and used in the following manner: The container is first filled with the fluid, for instance hand cream, which is to be discharged. In order to evacuate the air enclosed in the metering chamber and for a further object the slot 11 is provided. Since the slit 11 does not extend up to the opening 12 a small quantity of air 18 will remain in the upper portion of the discharge device and by the function of the discharge device this air cushion will be compres¬ sed and will have an elastically equalizing function. When it is desired to effect a discharge the co pressable thin-walled tubular part 14 is grabbed by the hand and is compressed more or less. If- for instance- a maximum discharge is desired the tubular part 14 is compressed to such an extent that it will come into contact with the inner portion 10. At the compression the quantity of fluid contained in the metering cham¬ ber will be brought under pressure since the return valve 12 closes and thus prevents backflow of fluid from the metering chamber to the con- tainer. When the pressure has reached the pre-determined value at which the closure 15, which is also a return valve, opens discharge takes place through the outlet opening which just has been kept closed by means of the closure 15. When the pressure on the tubular part 14 ceases there is a pressureequal - ϊzing and the return valve 12 opens and permits new fluid to flow into the metering chamber from the container until the metering chamber is again filled and thus ready for new discharging actions. As mentioned the air in the space 18 is compressed and this air cushion then serves as a resilient buffer which makes the discharge more soft and well defined. The membrane valve 15 preferably comprises plastics components made in an injection moulding process and which may be snapped into each other res¬ pectively in the mouth of the tubular portion 14. In a manner known per se it may comprise a first component which has a relatively thick-walled annular part 18, which by means of radial ribs 19 is connected to a cen- tral, axially extending stud 20 and a second component which preferably surrounds the annular part 18 and continues in a membrane 21 provided with a central outlet opening 22, which due to the pre-tension of the membrane is normally closed by means of the end portion of the stud 20. The membrane of course should be resilient and polypropene plastic has proven to be a suitable material for making the two components of the mem¬ brane valve.

Claims: CLA I MS 1. Device for discharging fluid from a container and including a meter¬ ing chamber (5) which has a flexible, tubular portion (14) the interior of which communicates with the container (1) by means of an inlet open- ing (13) such that fluid from this one may flow into the metering cham¬ ber via said inlet opening and that the metering chamber further has an outlet opening, which is normally kept closed by means of a self-closing closure (15) provided to open In response to a pre-determined pressure exerted upon the fluid in the metering chamber, c h a r a c t e r i z - e d in that in the metering chamber there is provided a tubular and relatively rigid inner portion which preferably is coaxial with the tubular portion of the metering chamber and is arranged in such a manner that the interior thereof communicates with the inlet opening (13) of the metering chamber, that in said inner portion (10) there is provided a return valve (12) which permits fluid to pass from the container (1) to the metering chamber (5) but not in the opposite direction and that further the inner portion (10) is so dimensioned relative to the flex¬ ible, tubular portion (14) of the metering chamber that there is gene¬ rated between the last-mentioned portions a space which is measured acc- ording to the maximum quantity of fluid which is to be discharged when the wall of said flexible, tubular portion (14) is pressed against the inner portion. 2. Device according to claim 1, c h a r a c t e r i z e d in that the metering chamber (5) and the inner portion (10) thereof consists of one single component, made from a plastics material with elastically resili¬ ent properties, which includes an outer, thin-walled portion (14), form¬ ing the flexible, tubular portion of the metering chamber, an annular, preferably relatively thick-walled end portion (9) which is preferably formed (8) for connection to the container (1) and a relatively thϊck- walled tubular portion (10) extending from the interior of said annular end portion (9) and constituting the inner portion of the metering cham¬ ber. 3. Device according to claim 1, c h a r a c t e r i z e d in that the return valve has an oblique, resilient tongue (12) acting against the interior surface of the inner portion. 4. Device according to claim 3, c h a r a c t e r i z e d in that the tongue (12) is made integral with the inner portion (10) and is contin¬ uous therewith in a front zone (17) as seen in the closing direction. 5. Device according to claim 1, c h a r a c t e r i z e d in that the inner portion has an axial, through slot (11) extending from the free end thereof and extending to the vicinity ° t e opposi e end of the inner portion. 6. Method for making a device according to one or several of the claims 1-5, c h a r a c t e r i z e d in that at least the inner portion (10) of the metering chamber and the return valve (12) are made in one piece in an injection moulding process, that the return valve is then given the shape of an elliptic tongue (12)' which extends from the end of the inner portion (10) which faces the container and from such position extends ob¬ liquely downwards and that the cumulation of material in the wall portion from which the tongue extends is so chosen that the slit which during the moulding process unevitably has to be apparent between the portion of the tongue (12) which is not continuous with the interior portion (10) and the corresponding wall of the inner portion will be eliminated after the solidification of the material due to the various shrinkage of the mate¬ rial and that the so obtained unit is sealingly connected to a container (1) and that further a self-closing closure is sealingly connected to the outer tubular portion (14). 7. Method according to claim 6, c h a r a c t e r i z e d in that the wall portion from which the tongue extends is given a wall thickness which is 3-6 times the wall thickness of the tongue and that the wall thickness of the tongue is chosen within the interval 0,2-0,6 mm. 8. Method according to claim 6, c h a r a c t e r i z e d in that the inner portion of the metering chamber is formed with an axial, through slot (11) extending from the free end thereof and extending to the vicin¬ ity of the opposite end of the inner portion.

Inventors: NILSON BILLY, NILSON, BILLY
Applicants: STERISOL AB
Application year: 1986
Main classification: F16K15
IPC codes: A47K5