DEVICE FOR METERING FLUID FROM A PRODUCT CONTAINER

Abstract: A device for metering fluid (4) from a pre-filled product container (2), which is generally symmetrical relative to a plane (5). The container has fastener means (5) projecting out around its circumference in said plane. The container includes outlet means (8, 9) and the device includes a chamber (31, 34) for receiving the container (2). The chamber (31, 34) includes means (35, 37, 32) for securing the container fastener means (5). One wall-half (34) of the chamber is intended to contact one container-half delimited by said fastener means and is made of a flexible material. The other chamber-half (31) can be dismantled from said one wall-half, to enable a full container (2) to be inserted into the chamber (34, 31) and an empty container to be removed therefrom. The device includes a fluid chamber (34, 36; 80) which is delimited by said one chamber wall-half (34), and the fluid chamber is provided with means (39) for delivering fluid to the fluid chamber in specific dosages for expelling corresponding dosages of fluid (4) from the product container (2).

Description: DEVICE FOR METERING FLUID FROM A PRODUCT CONTAINER The present invention relates to a metering device of the kind defined in the preamble of Claim 1, (EP-A-0 202 022), for metering fluid from a product container. Fluid substances are often produced to a high degree of purity, on the actual production site and can be packaged in a product container while retaining this high degree of purity. The product container can then be transported to a consumer site and the material dispensed from the product container in predetermined very precise dosages with the aid of a metering device. In this regard, it is, of course, important to prevent contamination of the product container via its dispensing opening. It is also important that the product container can be completely emptied, for at least two reasons. One reason may be because the product is expensive, while another reason may be because it is desirable to take care of the empty containers in a simple, convenient and/or safe manner and with the minimum of space requirements. A third reason may be because it is perhaps desirable to recycle the empty containers. Accordingly, one object of the present invention is to provide a device of the kind indicated above which, with the aid of simple constructional solutions, enables pre-settable, precise dosages of fluid to be metered accurately from the product container whilst preventing contamination of the fluid during the course of emptying the container, to the greatest possible extent. It shall also be possible to empty the container to a far-reaching extent. Another object of the invention is to provide a device with which the flexible wall material of the product container need not be elastically stretchable in its plane. Accordingly, an object of the invention is to provide a device with which one or more of the aforesaid drawbacks is avoided or minimized, and with which one or more of the indicated desiderata can be achieved either in total or in part. This object is achieved with a device according to the accompanying Claim 1. Further embodiments of the device are set forth in the dependent claims. The container will preferably have a spherical shape and include a circumferentially extending and outwardly projecting mounting flange in its symmetry plane. The container will also include an outlet means at the top of one of the container halves delimited by the flange. This outlet means may have the form of a hose or a nozzle. The chamber includes means for fastening the container flange. One chamber half, which is delimited by the chamber fastener means and intended to lie in abutment with a container half that includes no outlet means, is comprised of a flexible material. The other wall-half of the chamber is detachable in relation to said one wall-half, to enable a full product container to be inserted into the chamber and an empty container to be removed therefrom. The shape of the second wall-half of said chamber will suitably conform generally to the shape of the corresponding half of the container filled with said product. The device also includes a fluid chamber which is delimited by said one flexible chamber- wall. The fluid chamber is provided with means for delivering fluid to the fluid chamber in specific dosages, in order to expel corresponding dosages of fluid from the product container. The container is generally spherical when filled. The device includes means for emptying fluid from the fluid chamber after emptying of a product container, and the fluid infeed means also includes a metering means ' for feeding a set fluid dosage into the fluid chamber. The metering device includes suitable means for automatically re-setting the metering device to a starting position for a new metering operation upon completion of a preceding metering operation. The metering device may include means for adjusting the dosage delivered when the metering device is actuated. In one particular embodiment of the metering device, the device may include a vertically orientated plunger chamber which accommodates a plunger whose periphery seals against the wall of said plunger chamber and which can be moved reciprocatingly in an axial direction in the chamber between a forward position and an adjustable rear position. When in its forward position, the plunger seals against an inlet end of a passageway that leads to the fluid chamber. The plunger also has an axially extending through-penetrating bore in which there is mounted a check valve that closes in the flow direction away from the fluid chamber. The plunger is suitably arranged to float in the fluid. The check valve is adapted to open in response to upward movement of the plunger in the plunger chamber. The fluid may be tap water taken from the water mains. A closure device may be provided for closing and opening the flow of fluid to the plunger chamber, a position in which the device is closed and wherewith the fluid supply pressure is allowed to drive the plunger such as to deliver a pre-determined dosage to the fluid chamber when the closure device is opened. The container outfeed means may be include a closure device that functions to close the outlet means when the flow of product fluid is interrupted. In one simple embodiment, this closure device may consist of two rollers that are spring- biased towards one another and that act against the outer end- part of an elastically deformable spout forming said container outlet means. In one preferred embodiment, the fluid, which is driven into the device to deform the chamber and thus expel product therefrom, may be a liquid. Because the liquid is incompressible in practice, the volume of product dispensed from the device can be defined by a chosen volume of liquid delivered to the fluid chamber. Because the liquid does not even enter the product container chamber of the device, there is no risk of the fluid product being contaminated by the fluid delivered to the device for the purpose of expelling the product. As the product container is symmetrical in relation to a plane that includes the fastener flange, the container can be emptied of its contents to a very far-reaching extent. The product container is emptied to an exceptionally good extent, particularly when the product container is spherical in shape. As a result of this extremely complete emptying of the product container, the empty container can be recovered in a favorable manner, or dumped with a minimum of residual product. This is important when the product is harmful or very expensive. Furthermore, it is beneficial to the recovery of product containers when said containers have been emptied essentially completely. Because one half of the container is supported by a fixed wall during the whole of the emptying procedure, it is not necessary for the wall to be stretched elastically in its plane. The container wall may therefore be fiber-reinforced if so desired. And since the container halves have similar basic shapes, the container wall that is actuated by the flexible chamber wall will be pressed into the other container-wall part that is supported by the device wall while utilizing the flexibility of the container wall, wherewith the movement pattern of the movable container wall ensures effective and complete emptying of the product container. The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawing, in which Figure 1 illustrates schematically one embodiment of an inventive device; Figure 2 illustrates a metering valve for use with the inventive device; and Figure 3 illustrates an alternative metering valve for use with the inventive device. Shown in Figure 1 is a product container 2 which is filled with a fluid product 4. The container includes an equatorial flange 5 and a pole-located emptying spout 8 that includes an outlet 9. A filled container 2 can be inserted into an outfeed device that comprises two hemispherical shell-halves 31, 36 which can be mutually joined at a symmetry plane to form a spherical surface. In the illustrated case, the shell-halves 31, 36 are interconnected by means of a screw joint 32, 35. One of the shell-halves, the bottom half 31, includes in its central region a leadthrough 33 for the container spout 8. The other shell-half, the upper rigid half 36, is lined with a flexible material, preferably an elastic material, such as rubber, at 34, this lining 34 having a hemispherical shape so as to fit against the part-surface of the container 2 filled with product 4, above the flange 5. As will be evident from Figure 1, the full container 2 is placed in the bottom shell-half 31 so that the spout 8 is received in the leadthrough 33, wherein the flange 5 will thus rest against the edge of the shell-half 31. The shell-half 31 and the container 2 accommodated therein is now screwed into the internal thread 37, wherewith the flange 5 is clamped tightly between the edge of the shell-half 31 and the mounting flange 35 of the flexible wall 34, this flange being supported, in turn, by the end-part of the upper shell- half 36, said end-part carrying the threaded part 37. In this state, the bottom part of the container 2 (which bottom part may be rigid) will rest against the inner wall surface of the shell-half 31 over the whole of its area, whereas that part of the container 2 located above the flange 5 will lie against the flexible membrane 34 over the whole of its area, this area corresponding to the container area above the flange 5. The person skilled in this art will realize that the upper, rigid shell-half 36 may have any desired shape, providing that the inner wall of said shell-half provides room for the membrane 34. It will also be seen from Figure 1 that the upper, rigid shell- half 36 includes a conduit means 38 which is connected to a valve 39. As indicated at the bottom of Figure 1, the device may include a closure valve 40 for co-action with the container spout 8 when the container 2 is fitted in the device. As shown in Figure 1, the valve 40 includes two flange jaws 41, 42 which function to squeeze the spout 8 together so as to prevent the flow of fluid therethrough. The spout 8 may conveniently be comprised of a springy, elastic and generally tubular element. The movable jaw 41 is moved towards and away from its clamping position with the aid of drive means not shown. As can be seen from Figure 2, the valve 39 receives hydraulic fluid, e.g. tap water, from the mains supply, via a pipe 50, which includes a closing valve 51. The valve 39 includes a plunger chamber 52 in which a plunger 53 is axially movable. The plunger 53 carries on its underside a plate 55 that includes a stem 56 which extends through a guide opening 57 through the plunger 53. The plunger 53 also includes throughflow passages 58 which open out against the plate 55. The bottom surface of the plate 55 may seal against a seating 58 that forms the inlet to the conduit 58. The plunger 53 and the plate 55 may be comprised of material which is buoyant in the liquid (tap water) delivered to the chamber 52. The plunger 53 is biased upwards, by means of a spring 64 which supports against the plunger chamber 52. The plate 55 is biased against the underside of the plunger 53, by means of a spring 65 that supports against the plunger 53. An upper stroke limit of the plunger 53 is defined by means of a setting screw 60. A device according to Figure 1 that is fitted with the valve 39 illustrated in Figure 2 will function in the following manner. Assume that the valves 40, 51 are closed and that the plunger 53 of valve 39 is in its upper end position. If the valves 40, 51 are now opened, the plunger 53 will be driven downwards while influencing the pressure of the fluid in the conduit 50. Downward movement of the plunger 53 is terminated when the plate 55 comes into sealing contact with the seat 59, which may consist of an 0-ring or like element. As the plunger 53 moves downwards, there is dispensed through the valve 40 a quantity of fluid that corresponds precisely to the volume of fluid driven through the seat 59 by the plunger 53 and its plate 55. The volume of product fluid expelled through the spout 8 when the plunger is driven down from its upper end position in response to taking tap water from the mains supply via the conduit 50 and the valve 51 can thus be adjusted in the illustrated case by changing the upper limit- position of the plunger 53 with the aid of the setting device 60. The valve 40 is then closed, wherewith the pressure is equalized so that the plunger 53 is able to move in the chamber 52 to its upper limit-position under the influence of the spring 64 or under the influence of its intrinsic buoyancy, wherewith the plate 55 is moved downwards relative to the plunger 53 against the force of the spring 65 so that liquid can flow downwards through the passageways 58 in the plunger 53 to the space beneath the plunger 53 and the plate 55. The plate 55 may include a dogging element 68 which prevents the plate from releasing the plunger 53 and which forms an abutment for the spring 65. The valve 51 is now re-opened, causing the plunger 53 to again move downwards and therewith expel a pre-determined volume of product fluid through the tip 9 of the spout 8. The valves 40, 51 may be arranged to be opened and closed at the same time. As an alternative to the valve 39 shown in Figure 8 and the closure 40 shown in Figure 1, there may be used a plunger pump of the kind shown in Figure 3. This pump includes a pump chamber 52 which is delimited by the plunger 53, said plunger being provided with a maneuvering shaft 71 fitted with a handle 72. The valve 39 again includes a setting device 60 for setting a desired upper limit-position of the plunger 53. In addition to a closure valve 51, the supply conduit 50 also includes a check valve 75 that permits fluid to flow into the chamber delimited by the plunger 53. The outlet conduit 38 includes a check valve 76 which permits fluid to flow in the conduit 38. In the case of the Figure 3 embodiment, liquid is sucked through the conduit 50 and the check valve 75 as the plunger 53 is lifted by means of the shaft 71 and the handle 72, while reflux suction of liquid from the conduit 38 is prevented by a check valve 76. An adjustable liquid volume is defined between the upper and the lower limit-positions of the plunger 53. As the plunger 53 is driven to its bottom position, the check valve 75 blocks and the check valve 76 opens so that a corresponding fluid volume will be expelled from the product container 2. The outfeed tip 9 of the spout 8 may have the form of a narrow hose-section which in the absence of pressure difference between the interior space of the spout 8 and the spout surroundings affords an elastic closure of the spout tip 9, whereas the spout tip, or orifice, 9 will open when the product 4 is subjected to an elevated pressure in relation to ambient pressure. The space 80 between the walls 34, 36 is suitably provided with draining means that enables fluid to be emptied from said space 80, for instance in conjunction with changing product containers 2. In the simplest case, such drainage means may include a conduit which communicates with the space 80 at one end and which discharges drained liquid at its other end into a drain. The conduit may also include a closure valve. In accordance with a particularly preferred embodiment, the product container 2 is made of a flexible, preferably thin- walled material, wherewith the container wall will preferably not be stretchable at all in its plane. By providing the container with an equatorial flange 5, or with a ring of attachment tongues, it is ensured that the upper half-shell of the container 2 will be driven very accurately into the bottom half of the container with the aid of the membrane 34 and the liquid in the chamber 80, so that the upper wall of the container 2 will be pressed very accurately into the bottom hemispherical wall-half progressively from the equator 5, thereby driving essentially all product from the container 2 through the polar outlet, such that the container will contain very little or no residual product upon completion of an emptying process. The spherical shape has been found to minimize the risk of local and unpredictable residual volumes between the walls of the product container that meet when emptying the container of said product.

Claims: CLAIMS 1. A device for metering fluid (4) from a product container, said container (2) being generally symmetrical relative to a plane (5) and a having fastener means (5) which projects out around the perimeter of said container in said plane, wherein the container includes an outlet means (8,9), wherein the device includes an openable chamber (31,34) for receiving the container (2), wherein the container chamber delimits a fluid chamber (34 ,36; 80) via a flexible wall (34), and wherein the fluid chamber includes means (39) for delivering fluid to the fluid chamber in specific dosages for expelling corresponding dosages of fluid ( 4 ) from the product container (2 ) , characterized in that one wall-half (34) of the container chamber, said wall-half being intended to contact one container-half delimited by said fastener means (5), is comprised of a flexible material; and in that the other chamber-half (31), which can be dismantled from said one wall- half to permit a container (2) to be inserted into and removed from the chamber (34,31), forms a fixed support for the other container-half throughout the entire emptying sequence. 2. A device according to Claim 1, characterized in that the container (2) is generally spherical when full. 3. A device according to Claim 1 or Claim 2 , characterized in that the container fastener means (5) has the form of a tongue which widens essentially around the full circumference of the container (2 ) . 4. A device according to any one of Claims 1-3, characterized in that the fluid chamber (34,36,38,80) includes fluid emptying means. 5. A device according to any one of Claims 1-4, characterized in that the fluid delivery means (39) includes a metering means for delivering selected fluid dosages to the fluid chamber. 6. A device according to Claim 5, characterized in that the metering means includes means (53,55,58,59) for automatically resetting said metering means to a starting position for the delivery of a new dosage. 7. A device according to Claim 5 or Claim 6, characterized in that the metering means includes means (60) for adjusting the dosage delivered by actuation of the metering means. 8. A device according to any one of Claims 5-7, characterized in that said device includes a vertically orientated plunger chamber (52) that accommodates a plunger (53) whose circumference seals against the wall of the chamber (52) and which can be moved axially and reciprocatingly in the chamber between a bottom and an adjustable top position; in that the undersurface of the plunger carries a sealing plate (55) which seals-off passageways (58) extending axially through the plunger (53), said plate (55) being axially movable in relation to the plunger (53); and in that the underside of the plate (55) is intended to co-act with a seat (59) at the inlet of a conduit means which communicates with the fluid chamber (80). 9. A device according to any one of Claims 1-8, characterized in that the fluid chamber is intended to receive fluid in the form of pressurized water, for instance tap water taken from the water mains. 10. A device according to any one of Claims 1-9, characterized by a closure means (80) which functions to allow the container outlet means (8,9) to be closed temporarily.

Inventors: MAEKINEN ESA, MAEKINEN, ESA
Applicants: MAEKINEN ESA, MAEKINEN, ESA
Application year: 1997
Main classification: G01F11
IPC codes: G01F11