GB2042137A - Dispensing valves - Google Patents

Abstract

A valve assembly 1 is provided for attachment to a fluid reservoir 2, such as an infusion fluid reservoir or particularly a multi-dose injection vial, for delivering a dose of fluid e.g. a dose of infusion fluid or an antibiotic dose, from the reservoir to a fluid receiver e.g. an infusion fluid line or especially a hypodermic syringe 37. The valve comprises means which is actuated on mating with the fluid receiver to open the valve so as to deliver fluid from the reservoir to the receiver. Characteristically the valve also comprises a cover which covers the mating means. In preferred embodiments the valve further comprises a locking device for locking the fluid receiver into the valve, a cover 20 adapted to re-cover the valve mating means after each delivery of fluid, a gravity operated correct attitude device, and a valve in the form of a biassed movable piston 3. <IMAGE>

Description

SPECIFICATION Dispensing valves This invention relates to dispensing valves for delivering fluid from a reservoir thereof to fluid receivers, and in particular includes valves for delivering doses of fluid such a medicament solutions from multi-dose reservoirs to fluid receivers, such as hypodermic syringes.

Injection solutions, such as solutions of antibiotics, are customarily stored prior to use in multi-dose containers from which separate doses are withdrawn by means of a syringe as required. Such multi-dose containers are usually in the form of bottles which are closed at the neck by rubber plugs or septa, and in use the hollow hypodermic needle of the syringe is passed through the rubber plug, a dose of the solution is withdrawn from the bottle into the syringe, and the hypodermic needle is withdrawn from the rubber plug which, owing to its resilient nature, reseals the bottle. This system, however, suffers from many defects. For instance, small pieces of rubber may be broken away from the plug and may block the hypodermic needle or may even be injected into the patient with highly undesirable results.Alo unsterile air which is drawn into the bottle after removal of the dose may infect the contents with micro-organisms such as airborne bacteria as well as oxidise labile compounds, and thus the medicament solution must usually contain undesirable preservatives and antioxidants. Furthermore, plasticisers and other chemicals present in the ruber of the plug may pass into the medicament solution and contaminate it.

In a specialised application of a dosage applicator for delivering doses of substances, including medicinal substances, in a substantially liquified and pressurised condition into body cavities, it has been proposed (U.K. Patent No. 1,242,334) to dispense doses of the substance from a pressurised metal reservoir through a standard aerosol valve into the dosage applicator which is in the form of a tube fitted with a slidabe piston and having a valve which normally closes the port at its inlet/outlet end, for holding a dose of the substance in the applicator in a substantially liquified and pressurised condition.

The object of the present invention is to provide an improved dispensing valve assembly for attachment to a fluid reservoir for dispensing fluid from the reservoir to a fluid receiver, particularly for use in the clinical field where it is necessary to maintain fluids in substantially uncontaminated and sterile condition.

According to the present invention a valve assembly for attachment to a fluid reservoir for delivering a dose of fluid from the reservoir to a fluid receiver comprises means for mating with the receiver, said means being adapted to be actuated on said mating to open the valve and thereby deliver fluid from the reservoir to the receiver, and in which the valve comprises integral therewith a cover which prior to first use of the valve cover the mating means.

The valve of the present invention is characteristic- ally intended for use in the dispensing of fluids in general which require to be maintained in a high state of purity, and which may include isotope solutions e.g. Technetium Tc 99 M solutions, such as those used as medical diagnostic reagents. In preferred applications, however, the valve is use for dispensing fluids which are to be administered to patients undergoing medical treatment.For instance, the valve assembly may be used to dispense medical infusion and peritoneal dialysis fluids or especially fluids for injection by syringe into patients e.g. antibiotic solutions etc. thus the valve assembly may comprise a giving valve for attachment to an infusion fluid container e.g. an intravenous medicament and/or nutrient infusion bottle or bag, or especially a "giving" valve for attachment to a multi dose injection vial for dispensing fluid to hypodermic syringes.Such infusion fluid containers and multi-dose injection vials are typically constructed of transparent material, so that the contents can be viewed prior to withdrawal to check for contamination by extraneous particles to overt micro-organic growth; Furthermore, in a particular embodiment, a valve according to the invention may be used to dispense liquid from a first container to a solid in a second container; for instance, for use with materials such as vaccines and antibiotics which are unstable in solution and which are normally supplied as dry powders which are dissolved or suspended in a sterile vehicle immediately before use and used within a few days thereafter. Each container may have a separate valve assembly and connection of the two containers may be made by way of a suitable, sterile connecting passageway.Alternatively the valves for both containers are incorporated in a single valve assembly which includes means for connecting the two containers, as well as means for subsequently dispensing fluid from the second container.

The cover of the valve mating means advantageously substantially prevents contamination of the valve mating means with airborne bacteria or other contaminants prior to use of the valve, as is particularly desirable for dispensing of liquids used in medical treatments. Conveniently also the cover over the valve mating means prevents chance opening of the valve, for instance, as the result of tampering by a child or mentally disturbed or subnormal patient which would be not only wasteful of the reservoir contents but might also be potentially dangerous e.g. in the case when the fluid is a drug solution.

The construction and mode of operation of the valve cover of the present invention may vary widely, dependent interalia upon the type of fluid reservoir for which the valve is intended. Preferably the valve cover may provide an indicator of when the valve has been used and such an indicator may comprise a frangible portion, tab or stopper in the cover which must be broken or removed in order to effect or permit uncovering of the valve mating means for use. Also the valve cover may be such as to allow use of the valve on one occasion only, after which the valves must be reconditioned. For example, the valve cover comprises a locking device which locks the fluid receiver e.g. medical infusion line connector, into the valve, once the fluid receiver has been mated with the valve mating means and has opened the valve.Such indicators and locking devices are particularly applicable to medical infusion and peritoneal dialysis fluid container uses, for instance, to prevent or guard against use of the container on more than one occasion without special reconditioning or sterilisation e.g. to prevent cross infection from one patient to another or infection by fluid which has become contaminated during previous use.

In one embodiment of a cover for use with an infusion fluid container valve according to the invention, the cover is engaged with, though free to rotate on, the main valve body, and is adapted to lock the infusion line connector mated in the operative position with the valve mating means on rotation of the cover into a locked position, access to the valve mating means, for instance, being provided by a port in the cover wall initially closed by a frangible portion or stopper.

Also or alternatively, it may be desired to deliver a number of separate doses from a single reservoir e.g. for multi-dose injection vials, in which case the cover is preferably adapted to re-cover the valve mating means after each delivery. For instance, the cover is sprung or provided with other biassing means, such that, when not in use, it is biassed into a rest position in which it covers the valve mating means, the cover being movable against said biassing into a use position in which the valve mating means is exposed for mating with the fluid receiver.

Such a movable biassed cover is preferably so formed with respect to the body of the valve assembly e.g. with longitudinal ridges, grooves, flanges or the like which complement contours on the main valve body, such that movement is restricted to that between the correct rest and use positions.

It will be appreciated that under normal conditions on delivery of a dose of fluid from the reservoir the entry of a corresponding volume of gas is usually required to equalise the internal pressure of the reservoir with that of the outside enviroment, excepting, of course, the use of collapsible containers, such as collapsible infusion bags. In accordance with the invention any such inflow of gas is typically sterile, the inflow of gas preferably being filtered through bacteria-proof filters. The entry ports for this inflow of gas may be integral with the valve assembly and may preferably be opened by actuation of the mating means.

Preferably, however, the reservoir is pressurised with respect to the outside enviroment and the fluid is dispensed from the reservoir under pressure, advantageously without consequent inflow of unsterile air. It will be appreciated, of course, that use of pressurised reservoirs is not normally suitable for dispensing fluids for infusion into patients e.g.

transfusion fluids. Sterile, non-oxidising gas is typically used to pressurise the reservoir e.g., oxygenfree nitrogen.

Valve assemblies according to the invention, for attachment to such pressurised fluid reservoirs, usually comprise a gravity operated correct attitude device adapted to permit actuation and opening of the valve only if the valve assembly is in a correct predetermined attitude with respect to the reservoir.

Other valve assemblies, according to the invention, including those for use with medical infusion liquid containers may also comprise such correct attitude device, preferably to assist in preventing contamination of the container by external influences. It will be appreciated that if the valve were opened when the valve/reservoir assembly were in an incorrect orientation this might lead to unwanted venting of the pressurising gas from the reservoir. Usually the correct attitude is an upside down attitude with the reservoir above the valve assembly, though the correct attitude may be the other way up if, for instance, a dip tube is used to transfer fluid from the fluid level in the reservoir up through the valve assembly.

In some circumstances, however, it may be desirable to vent a small quantity of the pressurising gas through the valve, for instance, to expel from the valve mechanism after use liquid, which might otherwise deteriorate or become contaminated e.g.

by plasticisers from rubber seals etc. For this purpose, when using valves having correct attitude devices, it is normally necessary to invert the container/mated receiver assembly from the correct attitude after filling of the receiver whilst the valve remains open so as to vent a small quantity of gas through the valve, otherwise the correct attitude device prevents actuation of the valve and the venting of gas.

The valve used within the valve assembly of the present invention may be of any suitable form for mating with the fluid receiver, and actuating on said mating to open the valve. Typically the valve mating means is so shaped as to be adapted to mate with the type of fluid receiver for which the valve assembly is intended, and in some cases may be designed such that the mating means is capable of mating only with its corresponding fluid receiver.

Thus, for instance, the mating means is shaped for mating engagement with the connector of a medical infusion line or drip, or especially the mating means is shaped to mate with a hypodermic syringe, e.g.

with the nozzle of a hypodermic syring such as a Luer type, syringe. Preferably mating means for mating with syringes comprise means to reduce formation of gas bubbles in the syringe on dispensing of the fluid thereto, and such means may comprise a short tubular section which extends through the syringe nozzle into the syringe on mating, or alternatively, a shallow conical section, around the outlet of the mating means, which protrudes into the opening of the syringe nozzle on mating.In an alternative embodiment, the valve mating means is adapted to mate with the hypodermic needle of a syringe; for instance, the mating means comprising a thin passage to accomodate the hypodermic needle, the passage, and thus the needle, being connectable to the fluid reservoir on opening of the valve and the passage normally comprising a seal to seal around the hypodermic needle when in the passage.

Actuation of the valve may be encompassed by a movement of the mating means, e.g. under pressure from a fluid receiver, such as a syringe, from a rest position into a use position in which the valve is opened. Thus, in one form, the valve may comprise a movable piston having a passageway therethrough for fluid to flow from the reservoir into the fluid receiver, in which the piston is biassed e.g. by a spring or other resilient means, into a rest position in which the passageway is not connected to the fluid reservoir, and in which the piston is movable under pressure from the mated fluid receiver, against the biassing means into a use position in which the passageway is connected to the reservoir and fluid flows from the reservoir into the fluid receiver.The axis of such a valve piston may be oriented in any suitable direction with respect to the fluid reservoir; for instance the axis of the piston may be oriented along the axis of the mouth of the reservoir i.e.

normally along a vertical axis when in use, or more preferably the axis of the valve piston is in a plane perpendicular to the axis of the reservoir i.e. in a horizontal plane during use.

The valve piston preferably has ridges or grooves which co-operate with correspondingly shaped parts on the surfaces of the valve piston passageway within the main valve body to assist and restrict movement of the piston between the correct rest and use positions. Also the valve piston may incorporate a asecond passageway providing an inlet port for gas to enter the reservoir on outflow of fluid therefrom; or alternatively a gas inlet port may be provided in a second valve piston, usually positioned alongside the first fluid outlet valve piston.

In such piston valve arrangements the correct attitude device may comprise a pellet of solid material located free to move under the action of gravity in a passageway provided within either the main valve body or th piston and protrude therefrom into a corresponding recess provided within either the piston or main valve body when the valve assembly is in an incorrect attitude with respect to the reservoir. This pellet is adapted to protrude from the passageway into the corresponding recess when the valve is in a closed position and in an incorrect orientation with respect to the reservoir, and thereby act as a bolt locking the valve in that position and preventing movement of the valve piston into the use position.

Prefera bly the arrangement and structure of the valve is such that the rest volum of liquid in the valve is-substantially minimised, and further that contact of fluid with rubber seals and other materials which may act to contaminate the fluid is also substantially minimised.

In applications of the valve of the present inven tion for use with multi-dose injection containers, the valve is normally supplied connected to the multi dose container, usually containing the injection solution, and in preferred embodiment also contain ing the pressurising gas. Such combinations of valve with the loaded reservoir are included within the invention.

Furthermore the invention includes specific design embodiments, particularly for use with valve/multidose reservoir combinations, such as the provision of stabiliser fins, attached or adapted to be attached to the valve cover and possibly also the other end of the multi-dose container. Such stabiliser fins may conveniently provide a firm base on which the valve/container combination can rest during use and also assist in packaging of the valve/container combination e.g. in regularly shaped boxes, prior to use. In a further design refinement the valve cover may be provided with or adapted to be provided with a supply of sterilised hypodermic needles e.g.

located in slots or recesses in the cover.

Moreover, in a specialised application, the valve of the invention is adapted for use with a multi-dose container and a repeater type syringe e.g. the type of syringe used for mass vaccination programmes to counter disease epidemics. For instance, the valve may comprise two one way valves, one for allowing fluid to flow from the reservoir to the cylinder of the syringe e.g. on repriming of the syringe as the result of the action of a return spring on the syringe piston, and the other allowing for the consequent inflow of air into the reservoir, preferably through a bacteriaproof filter and in such a syringe it will be appreciated that the syringe nozzle will also comprise a one way valve to prevent air being sucked into the syringe on repriming.

Various features and advantages of valve assemblies according to the invention will now be described in greater detail, by way of illustration only, in the following description which refers to the accompanying diagrams, in which: Figure 1 shows a vertical section view, in a plane along the axis of the valve piston, of a dispensing valve attached to the neck of a multi-dose container, the valve piston being shown in the rest position; Figure 2 shows a similar view of the valve of Figure 1, through with the valve in use dispensing liquid into a syringe; Figure 3 shows a similar vertical section view of an adaption of the valve of Figure 1, incorporating a modified piston valve construction; Figure 4 shows a similar section view, in part, of a further similar valve assembly in which the valve cover incorporates a tamper indicator;; Figure 5 shows an external side elevation view of an infusion fluid container valve assembly according to the invention the assembly shown with the side-by-side giving and inlet valve pistons exposed and the combination giving tube and air inlet tube assembly mated therewith, the valve cover shown with the rhomboidal keyhole-shaped aperture in register with the exposed ends of the valve pistons.

Figure 6 shows a vertical section view of the arrangement shown in Figure 5 attached to an infusion fluid container, the section being in a plane through the line VI-VI of Figure 7, the valve piston shown however in the non-actuated position and without the combination giving tube and air inlet assembly attached.

Figure 7 shows a horizontal section view from below of the valve assembly of Figure 5, the section being in a plane through the line VII-VII of Figure 6, the valve pistons shown in the actuated position with the combination giving tube and air inlet tube assembly locked in position by the valve cover, and Figure 8 shows a side elevation view of the arrangement shown in Figure 7.

With reference to Figures 1 and 2, a valve for attachment to a pressurised multi-dose injection fluid container comprises a main valve body 1 which is attached to and seals the neck of a standard plastic-coated multi-dose injection fluid container 2, the valve body 1 being fitted with a slidable valve piston 3 and having a retractable cover 4 which, when at rest as shown in Figure 1, covers the valve piston.

The valve body 1 is made in one substantially cylindrical piece of injection moulded plastic and comprises at one end a stopper portion 5 of diminished diameter which is a push-fit for the neck 6 of the multi-dose injection bottle 2. Around the stopper portion 5 is an annular skirt 8 which fits over the lip 9 of the bottle 2, the skirt 8 terminating in an inturned annular rib 7 which catches behind the lip 9 and retains the body 1 on the neck 6 of the bottle 2.

The neck 6 of the bottle 2 is sealed by means of an elastomeric ~;b" ring 10 around the stopper portion 5 and also by means of an elastomeric ring 11 which is compressed between the valve body 1 and the lip 9.

The stopper section 5 has a straight tubular passage 12 therethrough for allowing egress of the contents of the bottle 2 when the valve is actuated. Below the skirt 8 is a shoulder 13 running completely round the body 1 for retaining the cap 4 thereon. The cap 4 is likewise moulded from a plastics material and is in the form of a tube closed at one end 15 which is a loose fit over the valve body 1. The cap 4 is biassed away from the valve body 1 by a coiled stainless steel spring 16 into the rest position, as shown in Figure 1, in which position the cap 4 is retained on the valve body 1 by the engagement of an inturned annular rib 17, located around the inside of the open end of the cap 4, with the shoulder 13 of the valve body 1.The extent of axial movement of the cap 4 into the use position, as shown in Figure 2, against the biassing force of the spring 16, is limited by abutment of the fins 20, arranged radially around the circumference of the cap interior, against the valve body 1. One or more of these fins 20 have extensions 21 which engage corresponding slots 22 in the valve body 1 and thereby ensure correct alignment of the access port 24 with the valve piston 3 when the cap 4 is moved into the use position.

The valve piston 3 is located in a tubular passageway 25 which tapers by way of two steps from a section of greatest diameter at its opening, through the side of the valve body 1 just below the shoulder 13, to a section of least diameter at the termination of the passageway 25 within the valve body 1. The valve piston 3, which is in the form of a similarly stepped moulded plastic cylindrical body and is a loose fit within the passageway 25, is biassed towards the opening of passageway 25 by a coiled stainless steel spring 26. The internal end of the spring 26 abuts an elastomeric ring 27 against a step of passageway 25 and the external end of the spring 26 abuts a corresponding step of the valve piston 3.

The pistons 3 is retained within the passageway 25 by a combination of plastic annular disc 30 and elastomeric annular disc 31, the plastic disc 30 being fixedly located in position by the rib around its circumference which seats in a corresponding annular groove around the mouth of the passageway 25.

The central hole through the discs 30 and 31 allow passage of a syringe hub 34 and similarly the external end of the piston 3 has a slightly tapering cylindrical recess 35 to accomodate the syringe hub 34. The piston 3 has a right angled passageway 36 through it for directing fluid flow into a syringe 37, the passageway 36 provided with an extension by stainless steel tube 38 embedded in the piston 3 adapted to enter the hole in the piston hub 34 and thereby assist in diminishing gas bubble formation when liquid flows in the syringe 37. When the piston is at rest, the annular elastomeric disc 27 is compressed slightly by the spring 26 and seals the internal end of the passageway 36, and "0" ring seals 40 and 41 provided around the piston 3 lie one either side of, and seal, the outlet of passageway 12.

The internal end of the passageway 25 has an elongate ridge 42 which engages with a corresponding elongate groove 43 in the end of the piston 3 and thereby ensures correct alignment of the passageways 12 and 36 when the valve is in use, as in Figure 2. A correct attitude device for the valve is provided by means of a short length of stainless steel rod 50 located in a passage 49 extending perpendicular from the wall of passageway 25 and blocked off at its other end by inset 51. The correct attitude device co-operates with a recess in the wall of the piston 3 opposite the passageway 49, the rod 50 being adapted to move under the action of gravity so as to enter the recess 52 and lock the piston 3 in the rest position as in Figure 1,when the valve/multi-dose bottle assembly is inverted.

In use, the valve/multi-dose bottle assembly is held with the bottle uppermost and the cap 4 is pushed upwards against the spring 16 until the access port 24 is aligned with the end of the piston 3.

The hub 34 of a syringe 37 is then inserted through the entry port 24, through the holes through the centre of discs 30 and 31, and engaged with the recess 35 in the end of the piston 3, the stainless steel tube 38 entering the hole in the syringe hub 34.

With the aid of the syringe 37 the piston is then pushed into the passageway 25 against the spring 26 until the passageways 12 and 36 come into alignment, and fluid is dispensed under pressure into the syringe 37.

Similar designs of valve may be used for nonpressurised containers, including infusion fluid containers, through it is normally necessary to provide in addition an inlet port to allow for influx of air consequent upon the outflow of fluid. Such inlet ports are preferably provided with a bacteria proof filter and may be provided by a passageway through a piston valve assembly, which may be the same or an auxiliary piston, to that containing the fluid outlet passageway.

With reference to Figure 3 an alternative form of piston valve is shown in which an adaptation of the movable piston 3 is used in the form of a movable collar 60 surrounding a fixed central portion 61.

When the syringe is engaged with the valve this collar 60 is moved to complete the fluid exit passageway by bringing the short passageway section 62 into alignment with the passage 63 and 64 thereby causing fluid to flow from the reservoir into the syringe.

Further with reference to Figure 4 a variant of valve is shown based on the standard movable piston design but incorporating a tamper indicator in the cap 4. At a point on the circumference of the top of the cap there is a flange 70 which locates in a recess 71 in the valve body 1 and thereby prevents movement of the cap 4 in an upward direction towards the use position. The flange portion 71 is detachable from the main part of the cap 4 being attached thereto by a weakened frangible portion 72.

The flange portion 71 must be broken away from the remainder of the cap 4 prior to use and thus provides a readily discernible "tamper" indicator, indicating when the valve has been previously used.

With reference to Figures 5,6,7 and 8, a valve assembly for attachment to an infusion fluid bottle comprises a substantially cylindrical main valve body 100 which is screw-fitted to the threaded neck 101 of a standard infusion bottle, the valve body 100 accommodation, side-by-side, a giving valve piston 102 and an air inlet valve piston 103, and having a cover 104 which is rotatable about the axis thereof.

The construction and arrangement of the valve assembly is similar in many respects to that of the single piston multi-dose injection fluid container valve assembly of Figures 1 and 2. Thus the valve body 100 is made in a substantially cylindrical single piece, of injection moulded plastic, and comprises at one end a stopper portion 105 of diminished diameter which is a push fit for the neck 101 ofthe infusion fluid bottle. Furthermore, around the stopper portion 105 is an annular skirt 106 which fits over the lip of the bottle neck 101, the skirt terminating in an inturned annular rib 107 which catches behind the shoulder 108 of the neck 101 and retains the body 100 thereon.Moreover, the mouth of the infusion fluid bottle is sealed by the combination of an elastomeric "0" ring 109 around the stopper portion 105 and an elastomeric ring 110 which is compressed between the valve body 100 and the end of the bottle neck 101.

The internal surface of the skirt is, however, screw-threaded to engage with the screw-thread around the outside of the bottle neck 101. Also the valve body 100 accomodates two valve pistons 102 and 103 instead of the single piston 3 of Figures 1 and 2, although the construction arrangement and function of the valve pistons 102 and 103 is substantially identical to that of valve piston 3 of Figures 1 and 2 described above. The slightly tapering cylindrical recesses 112 and 114 of the pistons 102 and 103 are of different diameter, however, to ensure correct coupling with the different sized "giving" tube connector hub 114 and air-inlet connector hub 115, as shown in Figure 7.Also the passageways 116 and 117 open into the recesses 112 and 113 at the centres of slightly raised conical protrusions 118 and 119 which in use protrude into the mouths of the connectors 114 and 115 to improve liquid/air-tight sealing therewith.

With reference to Figure 7, the connector hubs 114 and 115 are provided together in the form of an integral unit moulded from a plastics material, comprising the tubular connector hubs 114 and 115 both of which are tapered at one end to fit the tapering cylindrical recesses112 and 113, and pro- vided with externally ribbed portions 120 at their other end for receiving and retaining flexible tubes (not shown). Thebubs 114 and 115 are joined in parallel into an integral unit by two flat plates, one plate 122 perpendicular to the axes of the hubs and located towards the ribbed ends thereof and the other plate 123 lying between and in the plane of the axes of the hubs.The plate 122 acts as a thumb pressure plate during insertion of the connector hubs 114 and 115 and actuation of the valve pistons 102 and 103, and the plate 123 acts as a stop abutting against the part 124 of the valve body 100 limiting the depth of insertion ofthe hubs 14 and 115 into the valve assembly. The hubs 114and 115 are also joined by an arc shaped shoulder plate 125 which is perpendicularto the plate 123 and has a rhomboid shaped area tapering from the air inlet hub 115 end thereof. The arc-shaped shoulder plate 125 is adapted to be retained by the cover 104 when the hubs 114 and 115 have been inserted and the valve pistons 102 and 104 actuated as shown in Figure 7.

Alongside the hub 115 and parallel to the axis thereof a short plate 126 extends from the arcshaped plate 125 providing a fence which prevents the cover 104 being locked with the integral hub connector inserted in the wrong position.

The cover 104 is moulded from a plastics material in the form of a circular tube 128 closed at one end by a base 129. The wall of the tube 128 has two diametrically opposed slots 130 and 131 cut into it, extending from the open end of the tube down to the base 129 which is weakened along a line joining the slots by a groove 132. Adjacent the length oftheslot 131 an elongate angled fin 135 extends from the internal surface of the cover wall 128, and in combination with a groove 136 in the valve body provides the latch means for locking the cover 104 in the position shown in Figures 7 and 8. The external surface of the cover 104 has ridges 133 to assist in gripping when the cover is being rotated on the valve body 100.

The cover 104 is engaged with the valve body 100 by an annular rib 134, located at the internal junction of the tube wall 128 with the base 129, which engages a circumferential groove 135 around the end of the valve body 100. In order to fit the cover 104 to the valve body 100 the internal angled fin 125 is aligned with a vertical elongate slot 137 provided in the surface of the valve body and the cover is pushed home until the annular rib 134 clips into the circumferential groove 135 engaging the cover with the valve body.

Access to the pistons 102 and 103 is provided through a rhomboidal keyhole-shaped aperture 140 in the tubular wall 128 of the cover 104. Prior to use this aperture 140 is closed by a frangible portion of the wall 128 (not shown) which is broken away by pulling on a tab (not shown). In use the frangible wall portion is removed and the cover 104 is rotated in an anti-clockwise sense when viewed from above, drawing the fin 135 out of the slot 137 until the aperture 140 comes into register with the exposed ends of the valve pistons 102 and 103 as shown in Figure 5. The hubs 114 and 115 are then inserted into the recesses 112 and 113 and pushed home moving the valve pistons 102 and 103 into the actuated mode, the rhomboidal arc-shaped shoulder plate 125 being able to pass through the aperture 140 whilst the cover is in this position. Whilst the pistons 102 and 103 are kept in the actuated mode by maintaining thumb pressure on the plate 122, the cover 104 is further rotated in the anti-clockwise sense until the fin 135 engages with slot 136 in the valve body 100. In this fashion the connector hubs 114 and 115 are locked into the actuated valve assembly and in order to remove the hubs it is necessary to break the cap in two along the frangible groove 130. This prevents the container being used on more than one occasion with different "giving" tubes without return to the pharmacy for refilling, reconditioning and resterilising.

In use the hub 114 is connected to a "giving" set e.g. a dripline, and the hub 115 is connected to a bacteria-proof filter to provide a bacteria-free source of air to take the place of liquid flowing out of the infusion fluid bottle.

Claims (22)

1. A valve assembly for attachment to a fluid reservoir for delivering a dose of fluid from the reservoir to a fluid receiver comprising means for mating with the receiver, said means being adapted to be actuated on said mating to open the valve and thereby deliver fluid from the reservoir to the receiver, and in which the valve comprises integral therewith a cover which prior to first use of the valve covers the mating means.

2. Avalve according to Claim 1 in the form of a "giving" valve for attachment to an infusion fluid container for delivering fluid therefrom to an infusion fluid line.

3. A valve according to Claim 1 in the form of a "giving" valve for attachment to a multi-dose injection vial for dispensing fluid to hypodermic syringes.

4. Avalve according to any of the preceding claims, in which the valve cover provides an indicator of when the valve has been used.

5. A valve according to any of Claims 1,2 or 4, in which the valve cover comprises a locking device for locking the fluid receiver into the valve, once the fluid receiver has been mated with the valve mating means and has opened the valve.

6. A valve according to Claim 5, for use with an infusion fluid container, in which the valve cover is engaged with, though free to rotate on, the main valve body, and is adapted to lock the infusion connector mated in the operative position with the valve mating means on rotation of the cover into a locked position.

7. A valve according to Claim 1,3 or 4 for use with a multi-dose injection vial, in which the cover is adapted to re-cover the valve mating means after each delivery of fluid.

8. A valve according to Claim 7, in which the cover is provided with biassing means, such that, when not in use, it is biased into a rest position in which it covers the valve mating means, the cover being movable against said biassing into a use position in which the valve mating means if exposed for mating with the fluid receiver.

9. Avalve according to Claim 8 in which the movable biassed cover is formed with respect to the body of the valve assembly with longitudinal ridges, grooves, flanges of the like which complement contours on the main valve body, such that movement of the valve cover is restricted to that between the correct rest and use positions.

10. A valve according to any of the preceding claims comprising provision of means for a sterile inflow of gas to the reservoir.

11. A valve according to any one of the preceding claims comprising a gravity operated correct attitude device adapted to permit actuation and opening of the valve only if the valve assembly is in a correct predetermined attitude with respect to the reservoir.

12. A valve according to any of Claims 1,2,4,5, 6, 10 or 11, for use with an infusion fluid container, in which the valve mating means if shaped for mating engagement with the connector of a medical infusion line of drip.

13. A valve according to any of Claims 1,3,4, 7-11, for use with a multi-dose injection vial, in which the valve mating means is shaped to mate with a hypodermic syringe.

14. Avalve according to Claim 13, in which the valve mating means comprises means to reduce formation of gas bubble in the syringe on dispensing of the fluid thereto.

15. A valve according to any of the preceding claims, in which the valve comprises a movable piston having a passageway therethrough for fluid to flow from the reservoir into the fluid receiver, in which the piston is biassed into a rest position in which the passageway is not connected to the fluid reservoir, and in which the piston is movable under pressure from the mated fluid receiver, against the biassing means, into a use position in which the passageway is connected to the reservoir and fluid flows from the reservoir into the fluid receiver.

16. A valve according to Claim 15, in which the valve piston has ridges or grooves which co-operate with correspondingly shaped parts on the surface of the valve piston passageway within the main valve body to assist and restrict movement of the piston between the correct rest and use positions.

17. A valve according to Claim 15 or 16, in which the valve piston incorporates a second passageway providing an inlet port for gas to enter the reservoir on outflow of fluid therefrom.

18. A valve according to any of Claims 15-17, in which the valve has a correct attitude device comprising a pellet of solid material located free to move underthe action of gravity in a passageway provided within either the piston or main valve body when the valve assembly is in an incorrect attitude with respect to the reservoir.

19. Avalve according to any of the preceding claims in combination with and connected to an appropriate fluid reservoir.

20. A valve according-to any of the preceding claims substantially as hereinbefore described and illustrated with particular reference to Figures 1 and, or3.

21. A valve according Claim 4 substantially as hereinbefore described and illustrated with particular reference to Figure 4.

22. Avalve according to Claim 6 substantially as hereinbefore described and illustrated with particular reference to Figures 5, 6, 7 and 8.