FLUID DISPENSER

Abstract: There is disclosed a fluid dispensing container comprising a reservoir for holding fluid in fluid connection with a chamber through a first valve means, the first valve means acting substantially to prevent fluid flow from the chamber to the reservoir but permitting fluid flow in the opposite direction, the chamber being divided into a first portion comprising the valve means and a second portion by a means of fluid seal, movable within the chamber from a first position to a second position, the positions defining a dispensing volume, the movable seal comprising a second valve means which acts substantially to prevent fluid flow from the first portion to the second portion but which will permit fluid flow in the opposite direction and a conduit fluidly connected from the second portion of the chamber to a fluid outlet from the device, the minimum volume of the second portion together with the conduit being greater than or equal to the dispensing volume.

Description: FLUID DISPENSER The present invention relates to the field of fluid dispensers, in particular to means for dispensing a defined volume of fluid from a container It is often desirable when dispensing certain fluids to measure accurately the volume dispensed It is well known to use means such as graduated measuring containers to dispense fluid This relies on the person dispensing the fluid to measure the dose accurately Such caps are easily lost or detached from the fluid container It is also known to provide an upper reservoir in the container which can be pre-filled with the required volume which is then dispensed Such containers can spill fluid from the upper reservoir before dispensing the fluid which reduces the accuracy with which a volume dose can be dispensed and can be messy It would be desirable to provide a means of dispensing a fixed volume of fiuid which is integral to the container and which dispenses the same volume of fluid each time and which is not prone to loss of fluid prior to dispensing thus improving accuracy of the volume of fluid dispensed and reducing spillage The present invention provides a means to solve some or all of these problems Broadly in accordance with the invention there is provided a fluid dispensing container comprising a reservoir for holding fluid in fluid connection with a chamber through a first valve means, the first valve means acting substantially to prevent fluid flow from the chamber to the reservoir but permitting fluid flow in the opposite direction, the chamber being divided into a first portion comprising the valve means and a second portion by a means of fluid seal, movable within the chamber from a first position to a second position, the positions defining a dispensing volume, the movable seal comprising a second valve means which acts substantially to prevent fluid flow from the first portion to the second portion but which will permit fluid flow in the opposite direction and a conduit fluidly connected from the second portion of the chamber to a fluid outlet from the device, the minimum volume of the second portion together with the conduit being greater than or equal to the dispensing volume. Preferably the chamber comprises a tube and the movable means comprises a piston slidable within the tube. The conduit may be attached to the piston such that movement of the conduit moves the piston between the first and second positions. More preferably the conduit is a second tube slidably mounted within a supporting structure. Most preferably the supporting structure is constructed to fit in close frictional fit within the outlet of the fluid dispensing device. In a further aspect of the invention there is provided a dispensing device suitable for insertion into containers for fluid, the dispenser comprising a chamber comprising a first valve means mounted through an external wall of the device, the valve means acting substantially to prevent fluid flow to the inside of the chamber, but permitting flow in the opposite direction, the chamber being divided into a first portion comprising the valve means and a second portion by a means of a fluid seal, movable within the chamber from a first position to a second position the positions defining a dispensing volume, the movable seal comprising a second valve means which acts substantially to prevent fluid flow from the first portion to the second portion but which will permit fluid flow in the opposite direction, and a conduit in fluid connection with the second portion of the chamber the minimum volume of the second portion plus conduit being greater than or equal to the dispensing volume. Preferred features of the dispensing device for insertion into a conventional container for fluid are analogous to those for the fluid dispensing container given above. In particular it is advantageous that the maximum diameter of the device is small enough to fit through the neck of the container into which it is to be inserted. Preferably the length of the conduit should be sufficient that it protrudes from the container neck even when retracted into its first position. The supporting structure may be of a size to fit within the neck of the container and be held in place there by friction. Preferably the supporting structure has substantially the same diameter as (but just fractional less than) the inner diameter of the neck so that the supporting structure may be held in place by frictional contact alone. t will be appreciated that the container and device of the present invention can be used to dispense any suitable fluid not just liquids, for example powders or non-viscous liquids. Preferably the fluid is not too viscous. Preferred fluids to be dispensed include medicaments, (where dose is important) and oral hygiene products (e.g. mouthwashes). The invention is particularly advantageous for use by patients or users (e.g. the elderly or children) with difficulty accurately using prior art measuring devices such as measuring caps. Preferably the dispensing volume is greater than 5 ml as volumes larger than this can be dispensed most accurately with the device described herein. The maximum volume that can be dispensed by devices according to the invention is limited by the volume of the dispensing conduit (which in practise is limited by the height of the container) and the width of neck of the container if the device is to be inserted into a standard container. If the liquid dispensed is to be taken orally then a further limit on the width of the conduit is the average size of a human mouth. Typical volumes which can be dispensed according to the invention are from about 5 ml to about 100 ml, preferably about 10 ml to about 50 ml, more preferably about 30 ml. A specific non-limiting embodiment of the invention is now described with reference to the following examples and drawings in which: Figure 1 shows the dispensing insert of the invention in the first position; Figure 2 shows the insert of the insert of the invention in the second position from which fluid can be dispensed; Figures 3 and 4 show the components of the inserts shown in Figures 1 and 2; Figure 5 shows a sectional view of the valve shown in Figure 4; Figure 6 shows a sectional view of a bottle comprising the insert shown in Figures 1 to 5. The following Example describes two aspects of the present invention; a dispensing insert suitable for insertion into a bottle; and the bottle containing this insert. For convenience the bottle is only shown in Figure 6, but Figures 1 to 5 show features of the insert (without the bottle shown) which also apply to operation of bottle. The separate components of the insert are more easily seen in Figures 3 and 4, which show separately an inner assembly (1) designed to slide within an outer assembly (11). Suitable materials for this embodiment comprises plastics such as polypropylene or PVC. Figure 3 shows the inner assembly (1) which comprises an inner tube (3) one end of which forms a protruding saucer shaped piston (5) with a rim (7) made from an elastically deformable, flexible resilient material (e.g. a suitable plastic). The circumferential wall of the inner tube (3) has a hole (9) positioned just above the saucer piston (5). Figure 4 shows the outer assembly (11) which comprises an outer tube (13) leading to a cylindrical chamber (15) defined by two transverse walls (17,19) and a cylindrical wall (21). The internal bore of the chamber (15) is substantially the same diameter as the saucer piston (5). The top transverse wall (17) that is adjacent the outer tube (13) is of substantially the same saucer shape as piston (5). There is an one-way inlet valve (23) positioned in the cylindrical wall (21 ) close to the other bottom transverse wall (19) directly opposite the outer tube (13). The valve (23) is shown in more detail in Figure 5. It is constructed of a flexible material, such as a suitable plastic or rubber, forming a curved region with a slit opening (25). Liquid is allowed in through the slit (25) in the direction of the arrow A, but pressure against the slit (25) in the other direction forces the two halves of the slit (25) together, which prevents any liquid escaping from the chamber (23) Mounted on the end of the outer tube (13) opposite the chamber (15) is a locating web (27) of the same bore as the exterior of the chamber (15) Thus the outer assembly (11) can be dimensioned to just fit within the neck of any suitable bottle. A region (29) of the internal bore of the outer tube (13) at the end near the chamber (15) is roughened to increase frictional contact between the inner (3) and outer tubes (13) in that region The region of roughness (29) provides an improved fluid resistant seal between the two tubes to reduce leakage of fluid from the insert during dispensing whilst still allowing relative sliding motion between the tubes A dispensing insert (31) is assembled by inserting the inner assembly (1) within the outer assembly (11) so inner tube (3) slides within outer tube (13). This can be achieved by constructing the outer assembly (11) without bottom transverse wall (19), inserting the inner assembly through the chamber (15) and then attaching the bottom wall (19) (for example by heat welding) to form a fluid retaining seal with the rest of chamber (15) The assembled insert (31 ) is shown in Figures 1 and 2. Figure 6 shows a dispensing bottle (33) in which the insert (33) is positioned with the bottle (33) and its narrow neck (35). The insert (31) is held in place by the frictional fit between web (27) and the neck (35) A removable cap (37) seals both the bottle neck (35) and the inner tube (3) when the bottle is not being used to prevent leakage of fluid. To operate the bottle dispenser, first the dispensing insert (31 ) must be primed from the storage / dispensing position shown in Figures 1 and 6 To prime the insert (31 ), the inner assembly (1 ) is pulled upwards by grasping the section of inner tube (3) that protrudes from the outer assembly (13) This slides inner tube (3) up within outer tube (13) and moves the saucer piston (5) up to abut the top saucer shaped wall (17) of chamber (15) This is the priming position shown in Figure 2 At this point fluid is drawn from the bottle (33) through the one-way valve (23) and into the dispensing chamber (15) After fluid has filed the chamber (15) the inner tube (3) can be slide back through the outer tube (13) to return to the storage position shown in Figure 1 Pushing the inner tube (3) down forces the liquid in the chamber (15) around the flexible πm (7) of the saucer piston (5) The rim (7) acts as a valve as it can bend only in one direction due to its shape Thus that part of the chamber (15) above the piston (5) fills with fluid This is the pre-defined volume which determines the dose of liquid dispensed each time the dispenser is used In the storage position of Figure 1 the valve (23) is blocked by the curved edge of the saucer piston (5) The required volume of liquid now sits in that part of the chamber (15) above the piston (5) as well as part of the inner tube (3) as the liquid can enter the inner tube (3) via the hole (9) As the insert is in the rest position the cap (37) can be used to seal the bottle (33) and insert (31) after priming until the users is ready to dispense the liquid dose When the liquid dose is required, the cap (37) is removed if necessary to reveal the open top of the inner tube (3) The user grips the section of the inner tube (3) that protrudes from the outer tube (13) and pulls the inner assembly (1) up slowly This action pushes the remaining liquid in the chamber (15) through the hole (9) and into the inner tube (3) It also acts to prime the chamber (15) as described above In its m-use position with the inner tube (3) fully extended, both the piston (5) and the top wall (17) of the chamber (15) form a seal preventing liquid entering the tube (3) from the bottle (33) The user then places the protruding part of the tube (3) in the mouth or other receptacle and tilts the bottle (33) steadily until all the dose of liquid is removed from the inner tube (3). Should only one dose be required the user then returns the bottle (33) to vertical, pushes the inner tube (3) back to its storage position (see Figure 1) and replaces the cap (37). This produces an airtight seal to prevent any liquid leaving or foreign particles entering the liquid or the dispenser.

Claims: CLAIMS 1 A fluid dispensing container comprising a reservoir for holding fluid in fluid connection with a chamber through a first valve means, the first valve means acting substantially to prevent fluid flow from the chamber to the reservoir but permitting fluid flow in the opposite direction, the chamber being divided into a first portion comprising the valve means and a second portion by a means of fluid seal, movable within the chamber from a first position to a second position, the positions defining a dispensing volume, the movable seal comprising a second valve means which acts substantially to prevent fluid flow from the first portion to the second portion but which will permit fluid flow in the opposite direction and a conduit fluidly connected from the second portion of the chamber to a fluid outlet from the device, the minimum volume of the second portion together with the conduit being greater than or equal to the dispensing volume 2 A fluid dispensing container as claimed in claim 1 , in which the chamber comprises a tube and the movable means comprises a piston slidable within the tube 3 A fluid dispensing container as claimed in claim 2, in which the conduit is attached to the piston such that movement of the conduit moves the piston between the first and second positions 4 A fluid dispensing container as claimed in claim 3, in which the conduit is a second tube slidably mounted within a supporting structure 5 A fluid dispensing container as claimed in claim 4, in which the supporting structure is constructed to fit within the outlet of the fluid dispensing device and be heid in place there by friction 6 A dispensing device suitable for insertion into containers for fluid, the dispenser comprising a chamber comprising a first valve means mounted through an external wall of the device, the valve means acting substantially to prevent fluid flow to the inside of the chamber, but permitting flow in the opposite direction, the chamber being divided into a first position comprising the valve means and a second portion by a means of a fluid seal, movable within the chamber from a first position to a second position the positions defining a dispensing volume, the movable seal comprising a second valve means which acts substantially to prevent fluid flow from the first portion to the second portion but which will permit fluid flow in the opposite direction, and a conduit in fluid connection with the second portion of the chamber the minimum volume of the second portion plus conduit being greater than or equal to the dispensing volume 7 A fluid dispensing device as claimed in claim 6 in which the chamber comprises a tube and the movable means comprises a piston slidable within the tube 8 A fluid dispensing device as claimed in claim 7, in which the conduit is attached to the piston such that movement of the conduit moves the piston between the first and second positions 9 A fluid dispensing device as claimed in claim 8, in which the conduit is a second tube slidably mounted within a supporting structure 10 A fluid dispensing device as claimed in claim 9, in which the supporting structure is constructed to fit within the outlet of the fluid dispensing device and be held in place there by friction 11 A fluid dispensing container as claimed in any of claims 1 to 5, comprising a device as claimed in any of claims 6 to 10, in which diameter of the device is small enough to fit through the neck of the container into which it is inserted 12. A fluid dispensing container as claimed in claim 11 , in which the length of the conduit is sufficient that it protrudes from the container neck when retracted into its first position. 13. A fluid dispensing container as claimed in claim 12, in which the supporting structure is of a size to fit within the neck of the container and be held in place there by friction.

Inventors: BAKER IAN JAMES, BAKER, IAN, JAMES
Applicants: BAKER IAN JAMES, BOOTS CO PLC, BAKER, IAN, JAMES, THE BOOTS COMPANY PLC
Application year: 1997
Main classification: B67D5
IPC codes: G01F11