The present invention relates generally to pipette and cap assemblies for the removal and transfer of a fluid from a fluid container, such as a flask or bottle, to a pipette, for subsequent administration of a fluid, for example a liquid, such as a drug formulation, contained initially within the fluid container. For example, pipette and cap assemblies are known for the administration of paediatric paracetamol solutions, among others.

The known assemblies generally provide a cap assembly comprising: a cap configured to be seated on, and at least partially surround, a neck portion of a fluid container having an open proximal mouth and a closed distal bottom; and a pipette having a distal intake orifice, configured to be removably inserted into the cap via an opening in a proximal extremity of the cap, and extend into the fluid container to a depth decided upon by the user as a function of the remaining level of fluid in the fluid container.

The cap is generally provided with an axial opening along a central longitudinal axis of the container, through which the pipette is inserted into the fluid container. In order to facilitate intake of fluid into the pipette, the latter is usually provided with a plunger that, in a known manner, when moved in direction opposite to the distal intake orifice, causes a depression within the pipette and thereby aspirates fluid from the container into the pipette. In an opposite and known manner, administration of the fluid held within the pipette is accomplished by pushing the plunger within the pipette towards the distal orifice of the pipette, thereby expelling the fluid contained within the plunger. An example of such a known system has been commercialized by UPSA in France for many years.

One of the problems with the above type of product is that the pipette must be configured to have a length at least substantially equal to the height, or depth, of the fluid container, in order for it be manipulated by the hands of a user, and enable a user to withdraw fluid via the intake orifice of the pipette from the bottom of the container, or at any position in between the bottom of the container and the level of fluid contained within the container. Consequently, repeated insertion and withdrawal of the pipette into the fluid container causes fluid to dribble, or drip, off the outer surfaces of the pipette as it is withdrawn from the fluid container. This is problematic from a hygiene point of view, as there is an increased probability of the user having to touch the outer surfaces of the pipette with their fingers, hands, or even cloths or towels, in order to wipe of the excess fluid that has accumulated on the outer surfaces of the pipette. Depending on how well these surfaces are cleaned, or even, if they are not wiped off before, or after, administration, bacteria and other infectious agents may contaminate both the fluid, and potentially fall back into the fluid container, or potentially worse, the user or recipient of the administration of fluid from the pipette. In the case of a child, for example, in the pediatric paracetamol solutions known in the art, this can potentially be particularly problematic, as the risk of transmission of an infection is significantly increased.

Additionally, recent and/or ongoing changes in the legislation or administrative registration procedures relating to liquid formulations for medical applications, and in particular for pediatric formulations, have meant that such formulations are no longer allowed to contain preservatives, and/or anti-oxidants. The banning of such preservative compounds in these liquid formulations only serves to reinforce the need for the provision of technical solutions that reduce to the minimum the possibility of microorganism contamination during use.

Notwithstanding the risk of transmission of infectious agents, another problem with the accumulation of fluid on the outer surfaces of the pipette lies in the fact that many pediatric formulations in fluid form such as solutions, include sugars or syrups as an adjuvant in fairly significant dissolved concentrations. The inclusion of such sugary adjuvants has a tendency in general to cause the outer surfaces of the pipette, and indeed, the fluid container itself, to become sticky and unpleasant to handle or touch. The presence of sugars in solution on such surfaces also increases the risk of bacterial colony infections being established on said surfaces.

Ideally, therefore, it would be useful to be able to provide a cap assembly comprising a pipette which did not suffer from the disadvantages identified above.

Some attempts at overcoming these difficulties have already been described in the patent literature.

For example, published French patent application FR2758095A1 relates to a cap assembly comprising a pipette insertable through a central axial bore of the cap along a central longitudinal axis of said cap, wherein the cap assembly further comprises a feeder tube extending from a distal surface of an inner cylinder of the cap along said central longitudinal axis, and the pipette is prevented from being introduced into fluid container by a housing configured to receive said pipette in co-axial alignment along the central longitudinal axis. The housing and feeder tube are in axial alignment along the central longitudinal axis. The cap assembly is further provided with an air intake conduit.

One of the problems with the above described solution is that if the fluid container is knocked over, or turned upside down, or inclined at an angle such that the fluid contained within comes into contact with the container-facing openings of the air intake conduit, or the fluid intake orifice connected to the pipette, such fluid can accidentally escape from the fluid container, thereby potentially contaminating all of the surfaces which the proposed solution was intended to prevent.

Accordingly, one object of the present invention is to provide a pipette cap assembly for a fluid container such as a medicament flask or bottle, which is adapted and configured to prevent any such unwanted, undesired, or unexpected liquid flows and consequent potential contamination of an outside surface of the assembly and/or pipette.

Another object of the present invention is to provide a pipette cap assembly for a fluid container such as a medicament flask or bottle, as above, wherein said pipette cap assembly is adapted and configured to enable leakage-free selective communication between the intake orifice of the pipette and the inner volume of the fluid container.

Yet another object of the invention is to provide a pipette cap assembly for a fluid container such as a medicament flask or bottle, as above, in which said assembly is adapted and configured to permit selective communication between the intake orifice of the pipette and the inner volume of the fluid container, and simultaneously therewith, atmospheric exchange between the outside of the container and the inside of the container.

These and other objects of the invention will become readily apparent from the complete reading of the current specification.

According to any of the above objects therefore, there is provided a cap assembly comprising: a cap configured to be seated on, and at least partially surround, a neck portion of a fluid container having an open proximal mouth and a closed distal bottom; a pipette having a distal intake orifice, configured to be removably inserted into the cap via an opening in a proximal extremity of said cap; the cap assembly further comprising a feeder conduit extending into the fluid container and towards the closed distal bottom of said fluid container; wherein the cap assembly is configured enable selective movement of the pipette, when inserted into said cap, from a first, fluid flow prevented position in which the pipette and feeder conduit are not in fluid communicating alignment one with the other, thereby preventing fluid flow from the container into the pipette, into a second, fluid flow permitted position in which the pipette and feeder conduit are in fluid communicating alignment one with the other, thereby permitting fluid flow from the container into the pipette. As used herein, the terms proximal and distal are given in relation to habitual usage of the device to which those terms relate. For example, in the present case in a cap assembly for withdrawal of fluid from a fluid container via a pipette, the term “proximal” refers to an element being situated in the direction of the hand and/or fingers of the user manipulating the device, and distal refers to an element being situated in a direction spaced away therefrom, along an axis, for example a longitudinal axis of the device, or an axis of rotation, and in opposition to proximal. Thus for example, the pipette has a pipette body provided with a proximal extremity which is held, and or manipulated by the hands and or digits of the hand, and a distal extremity, the distal extremity of the pipette being provided with a distal intake orifice through which fluid is aspirated, and then subsequently expelled. A plunger is generally inserted into the inner volume of the pipette body via a proximal opening located at the proximal extremity of the pipette body.

The cap assembly comprises a cap configured to be seated on, and at least partially surround, a neck portion of a fluid container having an open proximal mouth and a closed distal bottom. The cap is generally configured and dimensioned to be seated in a sealing, or fluid-tight manner, on said neck portion, and is generally provided with either a snap, or push-fit mount, or alternatively, a screw thread mount for engaging with a correspondingly shaped and configured outer surface of the neck portion. To that end the cap generally comprises a generally cylindrically shaped outer body extending from a proximal extremity to a distal extremity, the cylindrically shaped body further having a central axial bore. The cap is additionally configured and shaped to provide a proximal, radially inwardly extending surface, which extends from the cylindrical outer body radially inwards into the central bore, and that at least partly closes said central bore, and in a corresponding manner, the mouth of the fluid container. The radially inwardly extending proximal closure surface can be suitably dimensioned in shape and form as desired, for example, it may be circular, elliptic, square rectangular, as required or desired to form a proximal opening in the cap assembly, having reduced dimensions compared to those of the central bore, through which said pipette can be removably introduced or inserted into the cap assembly.

Advantageously, and according to another object of the invention, the radially inwardly extending proximal closure surface defines a proximal opening having a substantially kidney bean-shape, arcuate, or arc-shape, or intersected double ellipse shape, extending around a central longitudinal axis of the bore.

Even more advantageously, and according to yet another object of the invention, the proximal opening has a first end and a second opposing end, wherein the first end and the second end have different diameters. According to yet another object, the above first end has a diameter greater than the diameter of the second end of the proximal opening. The result of having different diameters at the first and second ends of the proximal opening is that the end with the greater diameter will permit introduction and/or withdrawal of the pipette through the proximal opening in the first, fluid-flow prevented position, whereas the end with the smaller diameter will prevent introduction and/or withdrawal of the pipette in the second, fluid-flow permitted position.

The cap assembly further comprises a feeder conduit or tube, extending in a distal direction into the fluid container and towards the closed distal bottom of said fluid container, when the cap assembly is mounted on the fluid container. The feeder conduit or tube serves to allow fluid to be withdrawn from the fluid container up the feeder conduit and is connected to a corresponding outlet orifice provided on a distal surface of the cap assembly, as will be described in more detail hereunder.

The cap assembly is additionally configured to selectively move the pipette, when inserted into said cap, from a first, fluid flow prevented position in which the pipette and feeder conduit are not in fluid communicating alignment one with the other, thereby preventing fluid flow from the container into the pipette, into a second, fluid flow permitted position in which the pipette and feeder conduit are in fluid communicating alignment one with the other, thereby permitting fluid flow from the container into the pipette. Accordingly, fluid transfer from the fluid container to the pipette can only occur, for example, when the pipette has been moved from a closed, or fluid flow prevented position to an open, or fluid-flow enabled position whilst inserted in, and held by, the cap assembly.

The terms “fluid-flow prevented position”, and “fluid-flow enabled” or “fluid flow permitted position” as used herein thus refer to two different situations. In the first, fluid-flow prevented position, fluid from the container is actively prevented from leaving the container, i.e. no fluid such as a liquid drug formulation held within the container can escape to the outside environment, or contaminate the cap assembly or pipette. In the second, fluid flow enabled or permitted position, whilst fluid, such as a liquid drug formulation, is allowed to flow from the container into the pipette, for example, the configuration of the cap assembly still prevents such a liquid drug formulation coming into contact with any outside surfaces of the pipette, or the cap assembly itself.

Such selective movement can be achieved through a variety of different configurations of the cap assembly, but advantageously, such selective movement is achieved through a rotational movement of either the cap assembly, or the pipette, or both, about an axis of rotation of the cap assembly, and even more advantageously, about a central axis of rotation of the cap assembly that is also a longitudinal axis of the cap assembly. According to one object of the invention, the cap assembly comprises a drum located in the central bore, said drum being configured to selectively rotate about an axis of rotation from said first fluid flow prevented position to said second fluid flow permitted position.

According to another object of the invention, the cap assembly comprises a drum located in the central bore, said drum being configured to selectively rotate about an axis of rotation from said second fluid flow permitted position to said first fluid flow prevented position.

As will be apparent from the above, the drum is configured to rotate about an axis of rotation of the cap assembly, both from a closed to an open position, on the one hand, and from an open to a closed position, on the other hand.

Advantageously, the axis of rotation mentioned of the drum is coaxial with the central longitudinal axis of the bore of the cap.

According to another object of the invention, in the first, fluid flow prevented position, an intake orifice of the pipette and an outlet orifice of the cap assembly are in an angular rotationally displaced and unaligned position one with regard to the other.

According to yet another object of the invention, in the second, fluid flow permitted position, an intake orifice of the pipette and an outlet orifice of the cap assembly are in an angular rotationally aligned position one with regard to the other.

From the preceding paragraphs, it will be apparent that, when considered in relation to the axis of rotation, the intake orifice of the pipette and the outlet orifice of the drum in the first, fluid-flow prevented position, are angularly displaced, one with respect to the other. The angular displacement is the reason for the two orifices not being axially aligned one with the other, thereby preventing fluid from flowing from the fluid container into the pipette. Conversely, in the second, fluid-flow enabled, or permitted, position, the intake orifice of the pipette and the outlet orifice of the drum are in not only in angular alignment, i.e. they are angularly aligned about the axis of rotation that is coaxial with the central longitudinal axis, but they are also axially aligned, one with the other, and therefore can allow fluid to pass from the container into the pipette.

According to yet another object of the invention, the drum is a substantially solid revolutionaiy body of material, such as a cylinder, with an axis rotation matching that of central longitudinal axis of the bore. The drum is usefully comprised of a suitable plastic material, such as a polymer, for example, polypropylene, and can advantageously be an injection moulded body of such a material. According to a yet still further embodiment, the drum comprises an outlet housing having an outlet orifice, the outlet housing traversing, at least in part, the cylindrical body of material of the drum, and an intake orifice located at a distal surface of the drum, said intake orifice being connected to the outlet orifice and outlet housing via a connecting conduit. Thus, a connecting conduit extends from the outlet orifice, through the cylindrical body of the drum, and is in turn connected to an inlet orifice located on the distal surface of the cylindrical body of the drum. Advantageously, the outlet housing, outlet orifice, connecting conduit and intake orifice of the drum are all aligned along a longitudinal axis of the drum that runs parallel to the central longitudinal axis and axis of rotation of the central bore.

In yet another object of the invention, the outlet housing and connecting conduit are configured to receive and engage a distal region of the pipette, thereby aligning the intake orifice of said pipette, via said connecting conduit, with the intake orifice of the outlet housing.

The outlet housing outlet orifice and connecting conduit are furthermore, according to yet another object of the invention, shaped to receive a distal extremity of the pipette. Usually, such pipette distal extremities, as mentioned above, are frustoconically shaped or tapered leading towards the distal intake orifice of the pipette, which means that the outlet housing orifice and connecting conduit are suitably shaped with a corresponding complementary frustoconical recess to surround and engage in contacting engagement with the frustoconical area of the distal extremity of the pipette. In this way, the distal extremity of the pipette is suitably seated, and held, within the outlet housing outlet orifice and connecting conduit.

Additionally, the outlet housing and connecting conduit are shaped and configured to not only receive the distal region of the pipette, but also engage therewith in sealing engagement between an engagement surface of the distal region of the pipette, and the outlet housing outlet orifice and/or connecting conduit, thereby forming a fluid-tight seal. For example, where the distal extremity of the pipette has a cone or a substantially conical, or frustoconical shape, an outside surface of said cone will engage with an inside surface of the connecting conduit, and/or the outlet housing, when the pipette is inserted into the cap assembly, to form a fluid-tight seal.

According to a yet further object of the invention, the outlet housing is further provided with at least one, or a plurality of engagement surfaces, configured to engage via contacting engagement against at least one, or a plurality of corresponding mutually configured engagement surfaces provided on an outer surface of the pipette in the distal region of the pipette. Accordingly, the outer surfaces of the pipette in the distal region of said pipette are appropriately provided with at least one, or a plurality of mutually engaging surfaces, for example such as one, two or more spaced-apart projections extending radially outwardly from the outer surface of the pipette, for example, forming a substantially star-shaped engagement surface extending from a zone immediately adjacent to, and proximally located above, a habitual frustoconical tapering of the pipette.

Conversely, the outlet housing comprises at least one, or a plurality of mutually shaped engagement surfaces configured and shaped to receive such radial outwardly extending projections and engage in contacting engagement therewith, for example, such as a plurality of mutually shaped, radially spaced apart recesses, such that a rotation applied to the pipette about its own longitudinal axis, and corresponding axis of rotation, is transferred, via a torque generated by contacting engagement of the mutually engaging surfaces of the radial projections and corresponding engagement surfaces of the outlet housing, to the cylindrical body of the drum, for example, thereby causing the drum to rotate about the central axis of rotation of the bore. Such an arrangement of complementaiy contacting engagement surfaces can furthermore be configured in the opposite sense, i.e. one or more projections extending inwardly from an outlet housing inner surface, and one or more corresponding and complementaiy recesses formed in an outer surface of the pipette.

As will be apparent from the above description, and according to yet another object, rotation of the pipette in a first direction about a longitudinal axis of the pipette causes said pipette engagement surfaces to engage with the corresponding engagement surfaces provided within the cap assembly, and causes the pipette to move from a first, fluid flow prevented position into a second, fluid flow permitted position. In such a position, fluid can be withdrawn from the fluid container into the pipette.

Conversely, after withdrawal of fluid into the pipette, and according to a still yet further object, rotation of the pipette in an opposite direction to said first direction about a longitudinal axis of the pipette causes said pipette engagement surfaces to engage with the corresponding engagement surfaces provided within the cap assembly, and causes the pipette to move from the second, fluid flow permitted position into the first, fluid flow prevented position.

As will be apparent from the above therefore, rotation of the drum about the central longitudinal axis through the effect of the torque created when the pipette is rotated about its own longitudinal axis, and corresponding axis of rotation, therefore causes the intake orifice of the pipette to come into axial alignment with an outlet orifice of the cap, further details of which will be described hereunder, enabling fluid to flow, for example when a plunger in the pipette is moved in a proximal direction, from the fluid container, up the feeder conduit, into the distal intake orifice of the drum, through said connecting conduit, out through the outlet orifice of the outlet housing, and into the distal intake orifice of the pipette.

According to a still yet further object, the drum further comprises a pressure vent circuit configured, when the cap is mounted on the fluid container, to selectively enable the atmosphere within the fluid container to be exchanged with that of the ambient atmosphere outside of the fluid container.

Advantageously, said pressure vent circuit is configured to only permit exchange of the atmosphere within the fluid container with that of the ambient atmosphere outside said fluid container, when the drum body is in the second, fluid-flow permitted position. In this way, no venting occurs when the drum is in the first fluid-flow prevented position.

According to yet another object, the pressure vent circuit comprises a first orifice, located at the proximal surface of the drum, and a venting conduit extending from said first orifice through the drum body material and exiting at a second orifice, the second orifice being located at the distal surface of the drum. The venting circuit can also advantageously be provided with a suitable bidirectional filter, allowing atmospheric exchange in both directions, whilst filtering out any undesired particles. The filter can further be located in a position within the venting circuit that allows the filter to be exchanged when it has become blocked, or dirty, and usually this will mean that the filter is located in the first venting orifice, near the proximal surface of the drum, in order to facilitate easy exchange of the filter.

Accordingly, and as indicated above, the first orifice and the second orifice of the pressure venting circuit are selectively movable from a first venting disabled position in which said first and second venting orifices are not in fluid communication with the atmosphere of the fluid container, to a second venting enabled position in which said first and second venting orifices are in fluid communication with the atmosphere of the fluid container.

Advantageously, the outlet orifice of the outlet housing, and the outlet orifice of the venting circuit are angularly spaced apart around the central axis of rotation, such that rotation of the drum from the first position, to the second position, moves the outlet and inlet orifices of the outlet housing together with the respective outlet and inlet orifices of the venting circuit, into the fluid flow permitted, and respectively atmospheric exchange permitted, positions. In yet another object of the invention, the cap assembly further comprises a drum well having a distal bottom, and an open proximal top, with peripheral side walls extending from said distal bottom to said open proximal top to form said drum well.

According to another object, in the mounted position of the cap assembly on the fluid container, the drum well of the cap assembly is located within a bore formed by the open mouth and neck portion of the fluid container. The drum well furthermore advantageously sits within the central bore of the cap assembly at the same time as it is seated on the neck and within the bore formed by the open mouth and neck portion of the fluid container. The drum well can be sandwiched between the cylindrical outer body of the cap, and an upper peripheral and proximal facing edge of the neck portion of the fluid container, or alternatively the drum can form an integral part of the cap, for example through corresponding injection moulding, or alternatively spot welding such as ultrasound welding, of the well with the cap body.

According to yet another object, the drum well further comprises a peripheral annular flange extending radially outwards from the side walls of the drum well, at the open proximal top of said drum well, said peripheral annular flange then being seated on the proximal facing peripheral edge of the neck portion of the container, when the cap assembly is mounted on the fluid container.

According to a still further object, and even more advantageously, the drum well can be seated on a sealing membrane, for example an annular sealing membrane, which is in turn seated on the proximal facing peripheral edge of the neck portion of the fluid container, thereby forming a fluid- tight seal between the proximal facing peripheral edge of the neck portion and a distally facing surface of the drum well, such as, for example, the peripheral annular flange.

In yet a still further object, in the mounted position, the peripheral annular flange of the drum well further comprises a locking spigot portion extending outwards from the peripheral annular flange, preventing said drum well from rotating within the bore of the neck portion of the fluid container. The locking spigot portion engages with a corresponding recess provided in the cylindrical outer body of the cap, and once mounted on the neck of the fluid container, the locking spigot portion engages in stopping abutment with the corresponding recess to prevent any rotation of the drum well about the central axis of rotation. Alternatively, and according to another object, the recess can be provided in the peripheral annular flange, and a corresponding complementaiy locking spigot portion can be provided in the cap, which locking spigot portion extends from an inner surface of the cap into said recess on the peripheral annular flange, the functional effect when said cap and cap assembly is mounted on the neck portion of the container being to prevent the drum well from rotation within the bore and around said neck portion.

According to yet another object, the drum well further comprises a rotational abutment portion extending inwards into the drum well from a peripheral wall of said drum well and defining a first rotational stop surface and a second rotational stop surface. For example, a suitable rotational abutment portion can be provided by an inwardly projecting spigot, projecting into the inner volume formed by the drum well, and having a square, rectangular, circular, oval, or other suitably shaped cross-section, wherein the first rotational stop surface is located on one side of said suitably shaped cross-section, and the second rotational stop surface is located on an opposite side of said suitably shaped cross-section within the inner volume formed by the drum well.

According to another object, the drum well further comprises an outlet orifice to which the feeder conduit is connected. The feeder conduit outlet orifice allows fluid to flow into the drum when the drum intake and outlet orifices are aligned with said outlet orifice. In accordance with the invention as defined in the present specification, this can only occur when the intake orifice of the pipette, the outlet orifice of the drum, and inlet orifice of the drum have all been moved into the fluid-flow permitted position from the fluid-flow prevented position. Accordingly, when said feeder conduit outlet orifice is not in alignment with the outlet housing inlet and outlet orifices and intake orifice of the pipette, no fluid flow can occur from the container to the pipette, or within the drum.

According to yet another object, the drum well further comprises a venting orifice spaced apart from the outlet orifice. In a similar manner to that described above for the fluid-flow permitted position, the drum well venting orifice will only permit atmospheric exchange between the ambient atmosphere outside the fluid container, and the atmosphere within the fluid container, when said drum well venting orifice is aligned with the venting circuit provided in the drum, that is to say, only when said drum has been moved into the second, fluid-flow permitted position.

In a yet further object, the drum further comprises a recessed surface portion located on a side of the material of the drum, the recessed surface portion having a first stopping abutment surface, and an opposing second stopping abutment surface, the recessed surface portion defining an arc of permitted rotation of the drum body between the first stopping abutment surface and the second stopping abutment surface, the first stopping abutment surface of the drum and first rotational stop surface of the drum well preventing rotation of the drum in a first direction along the arc, and the second stopping abutment surface of the drum and the second rotational stop surface of the drum well preventing rotation of the drum in a second, opposite direction to the first direction. From the preceding sentence, it will be apparent that the recessed surface portion provided on the drum body is configured and shaped to interact, and engage with, the rotational abutment stopping surfaces provided, for example, as an inwardly projecting spigot extending from an inner surface of the drum well, to prevent further rotation of the drum in a first direction of rotation, and conversely in a counter direction of rotation, about the central longitudinal axis and corresponding axis of rotation. The movement of the stopping abutment surfaces provided in the recessed portion and the shape of the recess is that of an arc of a circle, located on a periphery of the drum, with the length and radius of curvature of said arc defining the degree of movement of the drum when rotating about the central longitudinal axis and abutting against the drum well inner projection.

Alternatively, and according to yet another object, the configurations of the drum well and drum, with regard to the rotational abutment portion extending inwards having a first rotational stop surface and a second rotational stop surface, on the one hand, and the corresponding recessed surface portion having a first stopping abutment surface, and an opposing second stopping abutment surface, can be respectively reversed. In such an alternative configuration, the rotational abutment portion would extend outwards from an outer surface of the drum, and would engage with a complementary, arch-shaped recessed portion provided on an inner surface of the drum well.

Furthermore, and as has been mentioned above, the radially inwardly extending proximal closure surface of the cap defines an arc-shaped proximal opening in the cap. The arc-shaped proximal opening has two opposing ends. At a first end, the arc-shaped opening of the cap in the first, fluidflow prevented position is configured and dimensioned to allow insertion and withdrawal of the pipette along the entire length and body of the pipette. However, at the second, opposing end, the arc-shaped opening, is configured and dimensioned to espouse the body of the pipette in a region located proximally to the distal region of the pipette. In such a case, the second end of the arcuate shaped opening will therefore not be sufficiently dimensioned to permit the distal region of the pipette to pass through the second end of the opening, thereby providing a means for preventing removal of the pipette in the second, fluid-flow permitted position. For example, this can be achieved by making the diameter of the second end smaller than the diameter of the first end of the opening, and by further providing the distal region of the pipette with an annular rib or ridge extending radially from an outer surface of the pipette to make the diameter of the pipette greater than that of the second end. The annular rib or ridge will thereby form an obstruction to the withdrawal of the pipette through the second end of the arcuate-shaped opening, as any attempt to withdraw the pipette in this second, fluid-flow permitted position will cause the annular rib or ridge of the pipette to abut against a distally facing surface of the reduced diameter second end of the proximal opening. The only way to remove the pipette in such a configuration would be to move the pipette back into the first, fluid-flow prevented, position, by rotating the pipette in a direction opposite to that which allowed the pipette to move into the second, fluid-flow permitted, position. Thus the pipette is locked in position in the second, fluid-flow permitted position until such time as the user wishes to withdraw the pipette from the assembly, with the resultant obligation to move the pipette back into the fluid-flow prevented position to enable the ridge on the pipette to pass through the greater diameter of the first end of the proximal opening.

According to yet another object, the drum further comprises a first raised contiguous sealing wall portion, extending from the distal surface of the drum in a distal direction and completely surrounding the intake orifice of the outlet housing. Advantageously, the first raised contiguous sealing wall portion extends substantially in an arc of rotation in anti-clockwise direction from said outlet housing intake orifice.

According to another object, the drum further comprises a second raised contiguous sealing wall portion, extending from the distal surface of the drum in a distal direction and completely surrounding the second orifice of the venting circuit. Advantageously, the second raised contiguous sealing wall portion extends substantially in an arc of rotation in a clockwise direction from said second orifice of the venting circuit.

The first and second raised contiguous sealing wall portions located on the distal surface of the drum as described above are configured and shaped to maintain a fluid-tight seal between the outlet orifice of the drum well, which is connected to the feeder conduit, and respectively, the venting orifice of the drum well, as the drum is rotated about the central longitudinal axis and corresponding axis of rotation. The sealing wall portions are therefore advantageously generally arcuate, kidney bean-shaped or have a shape representative of two intersected ellipses, so as to maintain a fluid- tight sealing wall with a proximal surface of the drum well, for example, in the even that the fluid container is tipped upside down. In this way, even if a user tries to withdraw fluid from the container in the upside down position of said container, in the fluid-prevented position, at the worst, an extremely small and limited volume of fluid might enter and fill the volume defined by the sealing wall portions.

Additionally, and advantageously, according to yet another object, the cap assembly further comprises a seal located between the distal surface of the drum and an inward proximal facing surface of the drum well. The seal is usefully comprised of any suitable known sealing material, for example, an elastomeric material or polymer compound, known per se in the art, for example, silicone or a thermoplastic elastomer, otherwise known as thermoplastic rubber, provided as a layer of such material between the distal surface of the drum and the proximal facing inward surface of the drum well.

Furthermore, and according to yet another object, the seal comprises a first traversing orifice, and a second traversing orifice, spaced apart from said first traversing orifice, said first traversing orifice being aligned with the intake orifice of the drum well, and said second traversing orifice being aligned with a venting orifice of the drum well. From this, it will be understood that the seal can advantageously be located fixedly within the drum well, for example by gluing, bonding, or otherwise adhering said seal to the proximal facing inward surface at the bottom of the well.

Alternatively, and according to a still yet further object, the arrangement relating to the contiguous sealing wall portions and seal can be configured in a different manner, according to which the drum well is provided with the first and second raised contiguous sealing wall portions located on, and extending from the inner surface of the bottom of the well in a proximal direction. The sealing wall portions in such a configuration extend in a similar manner, in a clockwise and counter-clockwise direction, from and around the respective outlet orifice, and venting outlet orifice, of the drum well. In such a configuration, the drum well can usefully comprise a seal located on the distal surface of the drum, for example, adhered or bonded thereto, and comprise a first traversing orifice, and a second traversing orifice, spaced apart from said first traversing orifice, said first traversing orifice being aligned with the intake orifice of the drum, and said second traversing orifice being aligned with the intake venting orifice of the drum.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described in more detail with regard to the accompanying figures, provided for the purpose of illustration and exemplification, in which:

Figure 1 is a schematic perspective exploded representation of a cap assembly comprising a pipette according to the present invention;

Figure 2A is a schematic perspective representation of the cap assembly of Figure 1 in a first position, preventing fluid flow from the container into the pipette;

Figure 2B is a schematic perspective representation of the cap assembly of Figure 1 in a second position, permitting fluid flow from the container into the pipette; Figure 3A is a schematic, cross-sectional representation of the cap assembly of Figure 1 in a first position, preventing fluid flow from the container into the pipette;

Figure 3B is a schematic, cross-sectional representation of the cap assembly of Figure 1 in a second position, permitting fluid flow from the container into the pipette;

Figure 4A is a schematic, axial cross-sectional representation of the cap assembly of Figure 1 in a first position, preventing fluid flow from the container into the pipette;

Figure 4B is a schematic, axial cross-sectional representation of the cap assembly of Figure 1 in a second position, permitting fluid flow from the container into the pipette;

Figure 5 is a schematic, perspective representation of a detail of the cap assembly of Figure 1;

Figure 6 is a schematic, perspective representation of another detail of the cap assembly of Figure 1.

DETAILED DESCRIPTION OF AN EXAMPLE

A schematic exploded perspective representation of a cap assembly according to the invention, referenced by the general reference numeral (1), is shown in the fluid-flow permitted position in Figure 1. The cap assembly (1) is designed to be seated on a fluid container (2) such as a flask or a bottle, the latter being designed to contain a fluid such as a liquid drug formulation. The fluid container (2) comprises a neck portion (3) having an open proximal mouth (4), a proximal facing peripheral edge (5) of the neck portion (3) defining the open proximal mouth (4), and a closed distal bottom (6). The cap assembly (1) also comprises a pipette (8) having a distal extremity (9) with a distal intake orifice (10) located at the distal extremity (9), and a cap (11).

The cap (11) of the cap assembly (1) comprises an outer cylindrical body (12) extending from a proximal extremity (13) to a distal extremity (14), defining a central bore (15) through the outer cylindrical body (12), and having a central longitudinal axis (16) extending through the length of the bore (15), which also coincides with a central axis of rotation of the cap assembly (1). The cap (11) is configured to be seated on, and at least partially surround, the neck portion (3) of the fluid container (2) in a sealing, or fluid-tight manner. Suitable fluid-tight sealing can for example be achieved via the locating of a suitable sealing layer, such as an annular or ring seal (17), on the proximal facing peripheral edge (5) of the neck portion (3). The cap (11) and is generally provided with either a snap, or push-fit mount, or alternatively, and as illustrated, a screw thread mount (18) for engaging with a correspondingly shaped and configured screw-threaded outer surface (19) of the neck portion (3). The outer cylindrical body (12) of the cap (11) further comprises a radially inwardly extending proximal closure surface (20), extending from the proximal extremity (13) into, and closing at least in part, the bore (15) to define an opening (21) in the proximal closure surface (20). The opening (21) is dimensioned and shaped to be smaller than the dimensions of the bore (15) of the outer cylindrical body (12), for example, and resembles a substantially arcuate, or kidney-bean, shaped intersection of a pair of ellipses, each having a respective opposing end (22, 23) which is adapted to receive and surround the pipette (8). The opening (21) is configured to permit insertion or introduction of the distal extremity (9) of the pipette (8) into the cap assembly (1) in the first, fluid-flow prevented position, but prevent removal of the pipette (8) in the second, fluid-flow permitted position. One end (22) of the arcuate shaped opening (21) is therefore dimensioned to allow insertion and removal of the pipette (8) in the first, fluid-flow prevented position, and the other opposing end (23) of the arcuate shaped opening (21) is dimensioned to prevent withdrawal of the pipette from the cap assembly in the second, fluid-flow permitted position. This can be achieved in a manner of ways, for example, by reducing the radius of curvature of the end (23) of the arc-shaped opening (21) that receives the pipette in the second, fluid-flow permitted position such that said end (23) substantially espouses the outer surface of the pipette in an area which is proximal to the distal region (24) and distal extremity (9) of the pipette (8). Before first use of the cap assembly (1), the cap (11) can be covered with an optional frangible, or removable, sealing cover (25), which covers the opening (21) of the cap (11) and provides an indicator to the user that the cap assembly (1) has not yet been used. The pipette (8) as illustrated, and as commonly found in commerce, further comprises a plunger (26), which can moved in a proximal and distal direction within the inner volume of the pipette, to withdraw fluid into, and respectively, expel fluid out of, the pipette (8) via the distal orifice (10).

The cap assembly (1) further comprises a drum well (27), and a drum (28), the drum (28) being seated in the drum well (27) and being rotatable around the central longitudinal axis (16) within said drum well (27) from a first fluid-flow prevented position to a second, fluid-flow permitted position, and vice-versa, as will be described in more detail here below. Both the drum well (27) and drum (28) are located in the central bore (15) of the cap (11) in coaxial alignment with the central longitudinal axis (16).

As illustrated in Figures 1 and 5, the drum well (27) comprises a distal bottom (29), and an open proximal top (30), with peripheral side walls (31) extending from said distal bottom (29) to said open proximal top (30) to form the drum well (27), and thereby defining an inner volume (32). The drum well (27) sits within the central bore (15) of the cap assembly (1) at the same time as it is seated on the neck portion (3) and within the bore (15). As is apparent from Figures 3A and 3B, the drum well (27) is sandwiched between the cylindrical outer body (12) of the cap (11), and an upper peripheral and proximal facing edge (5) of the neck portion (3) of the fluid container (2). To that end, the drum well (27) further comprises a peripheral annular flange (33) which extends radially outwards from the side walls (31) of the drum well (27), at the open proximal top (32) of said drum well (27), the peripheral annular flange (33) having a distally facing surface (34), and a proximally facing surface (35). The distally facing surface (34) is seated on the proximal facing peripheral edge (5) of the neck portion (3) of the fluid container (2), when the cap assembly (1) is mounted on the fluid container (2). The proximally facing surface (35) of the peripheral annular flange (33) is borne down upon by a distally facing surface (36) of the cap (11). The drum well (27) is optionally further seated on a sealing membrane, for example an annular sealing membrane (37), such as a ring seal, which is in turn seated on the proximal facing peripheral edge (5) of the neck portion (3) of the fluid container (2), the distally facing surface (34) of the peripheral annular flange (33) bearing down on the seal (37), thereby forming a fluid-tight seal between the proximal facing peripheral edge (5) of the neck portion (3) and the distally facing surface (34) of the peripheral annular flange (33). Additionally, the cap (11) further comprises a distally facing surface (38) formed by an inwardly projecting annular shoulder (39) extending from an inner surface (40) of the outer cylindrical body (12) of the cap (11). The inwardly projecting annular shoulder (39) is also configured and dimensioned to bear down, via the distally facing surface (38) of the shoulder (39), onto the annular sealing membrane (37), ensuring a fluid-tight seal between the cap (11), the drum well (27) and the proximally facing peripheral edge (5) of the neck portion (3). The annular sealing membrane (37), that is seated between the proximally facing peripheral edge (5) of the neck portion (3) and respectively, the shoulder (39) of the cap (11) and the peripheral flange (33) of the drum well (27), comprises a suitable sealing material, such as an elastomeric sealing material, for example, a thermoplastic polymer, or a silicone elastomer.

The peripheral annular flange (33) of the drum well (27) further comprises a locking spigot portion (40) extending outwards from the peripheral annular flange (33), the aim of which is to engage with a corresponding recess (41) provided in the cylindrical outer body (12) of the cap (11), thereby preventing the drum well (27) from rotating about the central longitudinal axis of rotation (16) within the bore (15).

The drum well (27) further comprises a rotational abutment portion (42) which extends inwards into the inner volume (32) formed by the side walls (31) and bottom (29) of the drum well (27). The rotational abutment portion (42) extends from an inner surface of a side wall (31) of the drum well (27) and defines a first rotational stop surface (43) and a second rotational stop surface (44). The aim of the first and second rotational stop surfaces (43, 44) is to prevent rotation of the drum (28) within the well (27) and around the central longitudinal axis (16), beyond a predetermined, or desired, angle of rotation. Such a predetermined, or desired, angle of rotation is suitably comprised between about 25° to about 45° around the central longitudinal axis (16). A suitable rotational abutment portion (42) can be provided by an inwardly projecting spigot, projecting into the inner volume (32) formed by the drum well (27), and having a square, rectangular, circular, oval, or other suitably shaped cross-section, wherein the first rotational stop surface (43) is located on one side of said suitably shaped cross-section of material constituting the spigot, and the second rotational stop surface (44) is located on an opposite side of said suitably shaped cross-section pf material constituting the spigot. The first and second rotational stop surfaces (43, 44) interact with the drum

(28) to limit drum rotation as will be described in more detail hereunder.

The drum well (27) further comprises an outlet orifice (45) to which a feeder conduit (46) is connected. The feeder conduit (46) extends in a distal direction into the inner volume of the fluid container (2), preferably substantially to almost touch the bottom (6) of the fluid container (2). In this way, fluid can potentially be withdrawn from the fluid container (2) irrespective of the level of remaining fluid in the fluid container (2). The outlet orifice (45) allows fluid to flow into the drum (28) when the drum (28) is in the fluid-flow permitted position. When the drum (28) is in the fluidflow prevented position, the outlet orifice (45) is blocked by a distal surface (47) of the drum (28).

The drum well (27) further comprises a venting orifice (48) spaced apart from the outlet orifice (45). The drum well venting orifice (48) will only permit atmospheric exchange between the ambient atmosphere outside the fluid container (2), and the atmosphere within the fluid container (2), when the drum well venting orifice (48) is aligned with a venting circuit (49) provided in the drum (28), that is to say, only when the drum (28) has been moved into the second, fluid-flow permitted position.

A second sealing membrane (50), comprised of elastomeric sealing material, for example, a thermoplastic polymer, or a silicone elastomer, is located between the drum (28) and the drum well (27) at the bottom (29) of the drum well (27), within the inner volume (32) formed by the side walls (31) and bottom (29) of the well (27). The second sealing member (50) is usefully provided with a corresponding fluid outlet orifice (51) and a corresponding venting orifice (52), which are located in a fixed, spaced apart, fluid-flow alignment with the outlet orifice (45), and the venting orifice (48), respectively, of the drum well (27). As has been mentioned above, the cap assembly (1) comprises a drum (28), located in the central bore (15), and the drum (28) is configured to selectively rotate about the central longitudinal axis (16), from a first fluid flow prevented position to a second fluid flow permitted position, and is further configured to selectively rotate about the central longitudinal axis (16) from said second fluid flow permitted position to said first fluid flow prevented position. In other words, the drum (28) can be selectively rotated by user interaction from a fluid-flow closed position to a fluid-flow open position, and vice-versa, from an open position to a closed position. By default, before first use of the cap assembly (1), the drum (28) is located in the first, fluid-flow prevented position. Additionally, the cap assembly (1) is configured, as has been discussed above, to require the user to return the cap assembly (1) to the first, fluid-flow prevented position, from the second, fluid-flow enabled position, in order to be able to withdraw the pipette (8) that has taken in fluid from the fluid container (2), which further increases the safety of the cap assembly when in use.

Figures 2A and 2B respectively illustrate perspective views of the cap assembly according to the invention, when appropriately mounted on the fluid container, in which Figure 2A represents the relative positioning of the pipette (8) at the first end (22) of the opening (21), in the first, fluid-flow prevented position, and Figure 2B represents the relative positioning of the pipette (8) at the second end (23) of the opening (21), in the second, fluid-flow permitted position.

The drum (28) is a substantially solid revolutionaiy body (53) of material, such as a cylinder, with an axis of rotation matching that of central longitudinal axis (16) of the bore (15). The drum (28) is comprised of a suitable plastic material, such as a polymer, for example, polypropylene, and is advantageously an injection moulded body of such a material. The drum (28) comprises an outlet housing (54) having an outlet orifice (55), the outlet housing (54) traversing, at least in part, the cylindrical body (53) of material of the drum, with an inlet, or intake, orifice (56) located at a distal surface (47) of the drum (28), said intake orifice (56) being connected to the outlet orifice (54) and outlet housing (53) via a connecting conduit (57). The connecting conduit (57) therefore extends from the outlet orifice (54), through the cylindrical body (53) of the drum (28), and is in turn connected to the inlet, or intake, orifice (56) located on the distal surface (47) of the cylindrical body (53) of the drum (28). The outlet housing (54), outlet orifice (55), connecting conduit (57) and intake orifice (56) of the drum (28) are all aligned along a longitudinal axis (58) of the drum (28) that runs parallel to the central longitudinal axis (16) and axis of rotation of the central bore (15). The outlet housing (54) and connecting conduit (57) are configured to receive and engage a distal region (24) of the pipette (8), thereby aligning the distal intake orifice (10) of the pipette (8), via said connecting conduit (57), with the intake orifice (56) of the outlet housing (54). Figures 3A and 3B illustrate a cross-sectional representation of the cap assembly (1) when mounted on the fluid container (2), respectively in the first, fluid-flow prevented position (Fig. 3A) and the second, fluid-flow enabled position (Fig. 3B), with the latter being a representation of the various components of the cap assembly (1) after rotation of the drum (28) about the central longitudinal axis (16), as will be described in more detail hereafter. It will be readily apparent from Figures 3A and 3B that the outlet housing (54) and connecting conduit (57) are shaped and configured to not only receive the distal region (24) of the pipette (8), but also engage therewith, for example via contacting engagement of the distal region (24) of the pipette (8) within the outlet housing (54), outlet housing outlet orifice (55) and connecting conduit (57) to form a fluid-tight seal. For example, as illustrated in Figures 3A and 3B, a series of concentrically aligned shoulders (59, 60, 61) that decrease in diameter in a distal direction through the body (53) of the drum (28) are provided within the outlet housing (54), these shoulders (59, 60, 61) forming engagement surfaces, which engage via contact with corresponding engagement surfaces (62, 63, 64) provided on an outer surface (65) of the pipette (8) in the distal region (24) of the pipette (8). Similarly, the connecting conduit (57) is shaped to receive the distal extremity (9) of the pipette (8). Usually, such pipette distal extremities (9) are frustoconically shaped or tapered in the direction of the distal intake orifice (10) of the pipette (8). The connecting conduit (57) extending in a distal direction from the outlet housing (54) is accordingly suitably shaped with a corresponding complementary frustoconical recess to surround and engage in contacting engagement with the frustoconical area of the distal extremity (9) of the pipette (8). In this way, the distal extremity (9) of the pipette is suitably seated, and held, within both the outlet orifice (55) of the outlet housing (54), and the connecting conduit (57). The outlet housing (54) is further provided with a plurality of engagement surfaces (66), configured for contacting engagement with a corresponding plurality of mutually configured engagement surfaces (67) provided on an outer surface (65) of the pipette (8) in the distal region (24) of the pipette (8). The outer surfaces (67) of the pipette (8) in the distal region (24) of the pipette (8) are therefore appropriately provided with a plurality of contacting engagement surfaces, for example such as one, two or more spaced-apart projections (67), extending radially outwardly from the outer surface (65) of the pipette (8), for example, forming a substantially star-shaped engagement surface, when viewed along the central longitudinal axis, extending from a zone immediately adjacent to, and proximally located above, the habitually shaped frustoconical tapering of the pipette (8). Conversely, the outlet housing (54) comprises a plurality of mutually shaped engagement surfaces (66) configured and shaped to receive such radial outwardly extending projections and engage in contacting engagement therewith, for example, such as a plurality of mutually shaped, radially spaced apart recesses (66). The recesses (66) of the outlet housing (54) and the radial outwardly extending projections (67) of the pipette (8) engage and cooperate, via contact with each other, in such a way that a rotation applied to the pipette, for example, through a user of the assembly grasping the pipette with fingers, and/or thumb, and twisting the pipette, about its own longitudinal axis, and own corresponding axis of rotation, will be transferred, via the torque generated by the contacting engagement of the mutually engaging surfaces, to the cylindrical body (53) of the drum (28), thereby causing the drum (28) to rotate about the central longitudinal axis (16) of the bore (15).

As will be apparent from the above, rotation of the pipette (8) in a first direction, about the central longitudinal axis (16), through the effect of the torque created thereby, causes the drum (28) to rotate out of the first fluid-flow prevented position, around said central longitudinal axis (16), and into the second, fluid-flow permitted position, bringing the intake orifice (10) of the pipette (8) into axial alignment with the outlet orifice (45) of the drum well (27), which outlet orifice (45) is connected to the feeder conduit (46). In such an alignment, fluid is therefore permitted to flow from the fluid container (2), for example, when a plunger (26) in the pipette (8) is moved in a proximal direction, up the feeder conduit (46), into the distal intake orifice (56) of the drum (28), through the connecting conduit (57), out through the outlet orifice (55) of the outlet housing (54), and into the distal intake orifice (10) of the pipette (8), thereby filling the pipette (8). Conversely, counterrotation of the pipette (8), i.e. in a second direction opposite to the first direction indicated above, causes the drum to rotate out of the second, fluid flow permitted position, back into the first, fluidflow prevented position, and brings the intake orifice (10) of the pipette (8) out of axial alignment with the outlet orifice (45) of the drum well (27) once again.

As is further apparent from a comparison of Figures 3A and 3B, in the first, fluid flow prevented position, the distal intake orifice (10) of the pipette (8) and the outlet orifice (45) of the drum well (27) are in an angular rotationally displaced and unaligned position with respect to one another. Conversely, in the second, fluid flow permitted position, the distal intake orifice (10) of the pipette (8) and the outlet orifice (45) of the drum well (27) are in an angular rotationally aligned position with respect to one another.

Expressed in a different way, when considered in relation to the central longitudinal axis (16), and coincident axis of rotation of the cap assembly therefore, the distal intake orifice (10) of the pipette (8) and the outlet orifice (45) of the drum well (27), in the first, fluid-flow prevented position, are angularly displaced, one with respect to the other. The angular displacement is the reason for the two orifices not being axially aligned one with the other, and this lack of axial alignment prevents fluid from flowing from the fluid container (2) into the pipette (8). Conversely, in the second, fluid- flow permitted, position, the intake orifice (10) of the pipette (8) and the outlet orifice (45) of the drum well (27) are not only in angular alignment, i.e. they are angularly aligned about the axis of rotation that is coaxial with the central longitudinal axis (16), but they are also axially aligned one with the other, along a longitudinal axis (58) that runs parallel to the central longitudinal axis (16), and therefore can allow fluid to pass from the container (2) into the pipette (8).

The drum (28) further comprises a pressure vent circuit (49) configured, when the cap assembly (1) is mounted on the fluid container (2), to selectively enable the gaseous atmosphere within the fluid container (2) to be exchanged with that of the ambient atmosphere outside of the fluid container (2). The pressure vent circuit (49) is additionally configured to only permit exchange of the gaseous atmosphere within the fluid container (2) with that of the ambient atmosphere outside said fluid container (2), when the drum (28) is in the second, fluid-flow permitted position. In this way, no venting occurs when the drum (28) is in the first fluid-flow prevented position, thereby limiting any untoward or accidental leakage from the fluid container into the environment outside of the container, for example, due to the fluid container (2) being knocked over, or tipped upside down. Accordingly, the pressure vent circuit (49) comprises a first orifice (68), located at the proximal surface (69) of the drum (28), and a venting conduit (70) extending from said first orifice (68) through the drum body (53) material and exiting at a second orifice (71), the second orifice (71) being located at the distal surface (47) of the drum (28). The venting circuit (49) is advantageously provided with a suitable bidirectional filter (72), allowing in principle atmospheric exchange in an both an inwards and outwards direction, whilst filtering out any undesired particles. As used in the present context, the expression “inwards” refers to gaseous atmospheric flow into the venting circuit (49) in the direction of the fluid container (2), and the expression “outwards” refers to gaseous atmospheric flow from the fluid container (2) through the venting circuit (49) to the environment outside the fluid container (2). Furthermore, and as illustrated in Figures 1, 3A and 3B, the filter (72) is suitably located in the first venting orifice (68), near the proximal surface (69) of the drum (28), in order to facilitate easy exchange of the filter (72) should it become clogged or dirty. The first orifice (68) and the second orifice (71) of the pressure venting circuit are therefore selectively movable from a first venting disabled position in which said first and second venting orifices (68, 71) are not in fluid communication with the atmosphere of the fluid container (2), to a second venting enabled position in which said first and second venting orifices (68, 71) are in fluid communication with the atmosphere of the fluid container (2). Such selectively engageable venting can be achieved in substantially the same manner as for the selective fluid-flow positions, by providing that the outlet orifice (55) of the outlet housing (54), and the first orifice (68) of the venting circuit (49) be positioned one relative to the other in angularly spaced apart locations around the central longitudinal axis (16), such that rotation of the drum (28) from the first position, to the second position, moves the outlet (55) and inlet orifices (56) of the outlet housing (54) together with the respective first (68) and second (71) orifices of the venting circuit (49), into the fluid flow permitted, and respectively atmospheric exchange permitted, positions.

As an example of one such possible configuration of the angular, spaced apart relative positioning of the inlet and outlet orifices (56, 55) of the outlet housing (54), and the first and second orifices (68, 71) of the venting circuit, reference is made to Figures 4A and 4B. In these figures an outlet orifice (55) of the outlet housing (54), on the one hand, and a first orifice (68) of the venting circuit (49), on the other hand, are illustrated in a correspondingly angular spaced-apart relationship around the central longitudinal axis (16) of the bore (15).

Figures 4A and 4B, also show a further aspect of the drum (28), wherein said drum (28) comprises a recessed surface portion (73) located on a side of the body (53) of the drum (28), the recessed surface portion (73) having a first stopping abutment surface (74), and an opposing second stopping abutment surface (75). The recessed surface portion (73) defines an arc of permitted rotation of the drum body (28) between the first stopping abutment surface (74) and the second stopping abutment surface (75), in which the first stopping abutment surface (74) of the drum (28) and first rotational stop surface (43) of the drum well (27) come into abutting contact with each other to prevent rotation of the drum (28) in a first direction along the arc, and the second stopping abutment surface (75) of the drum (28) and the second rotational stop surface (44) of the drum well (27) come into abutting contact with each other to prevent rotation of the drum (28) in a second, opposite direction to the first direction along said arc of permitted rotation. The stopping abutment surfaces of the recessed surface portion (74, 75) on the drum body (28) therefore interact, and engage in stopping abutment with the inwardly projecting spigot (42) extending from the inner surface of the drum well (27), to prevent further rotation of the drum in a first direction of rotation, and conversely in a counter direction of rotation, about the central longitudinal axis and corresponding axis of rotation. As indicated above, the shape of the recessed portion (73) is that of an arc of a circle, and is located on a periphery of the drum (28), with the length and radius of curvature of said arc defining the relative degree of movement of the drum (28) when rotating about the central longitudinal axis (16) and abutting against the drum well inward projection (42).

Figure 6 illustrates a detail of the drum (28) when viewed from the distal facing surface (47) thereof. In this view, the drum (28) further comprises a first raised contiguous sealing wall portion (76), extending from the distal surface (47) of the drum (28) in a distal direction and completely surrounding the intake orifice (56) of the outlet housing (54). The first raised contiguous sealing wall portion (76) extends substantially in an arc of rotation in anti-clockwise direction around the central longitudinal axis (16) from said outlet housing intake orifice (56). Also shown is a second raised contiguous sealing wall portion (77), extending from the distal surface (47) of the drum (28) in a distal direction and completely surrounding the second orifice (71) of the venting circuit (49). The second raised contiguous sealing wall portion (77) extends substantially in an arc of rotation in a clockwise direction around the central longitudinal axis (16) from said second orifice (71) of the venting circuit (49). The first and second raised contiguous sealing wall portions (76, 77) are configured and shaped to maintain a fluid-tight seal between the outlet orifice (45) of the drum well (27), which is connected to the feeder conduit (46), and respectively, the venting orifice (48) of the drum well (27), as the drum (28) is rotated about the central longitudinal axis (16) and corresponding axis of rotation. The sealing wall portions (76, 77) are therefore generally arcuate, kidney bean-shaped or have a shape representative of two intersected ellipses, so as to maintain a fluid-tight sealing wall with a proximal surface of the drum well (27), or as illustrated, with a proximal facing surface of the seal (50) located at the bottom of the drum well (27). In the event that the fluid container (2) is tipped upside down, and where a user tries to withdraw fluid from the container (2) in the upside down position of said container (2), even with the drum (28) in the fluidflow prevented position, at worst, only an extremely small and limited volume of fluid might enter and fill the volume defined by the sealing wall portion (76) surrounding the inlet orifice (56) of the outlet housing (54).

An example of how the cap assembly is used can be briefly described as follows. The cap assembly (1) is snap-fit mounted onto the neck portion of the fluid container, for example, a standard medicine bottle containing a paediatric liquid paracetamol formulation. The pipette (8) is inserted via its distal extremity through the opening (21) in the cap (11) into the outlet housing (54) of the drum. The outlet housing recessed engagement surfaces (66) and corresponding engagement surfaces provided on the outer surface (24) of the pipette, for example, outwardly spaced-apart radial projections (67) extending from said outer surface (24), come into contacting engaging contact with each other, when the pipette is inserted into the cap assembly (1), and the conical distal extremity (9) of the pipette (8) is held in position by a correspondingly complementary shaped recess in the connecting conduit (57), said holding position also providing a fluid-tight seal between the connecting conduit and the distal extremity (9) of the pipette (8). In this way the distal intake orifice (10) of the pipette (8) is held axially in position in alignment with the outlet housing outlet (55) and connecting conduit (57), in the first, fluid-flow prevented position. Rotation of the pipette (8) by the user about the longitudinal axis (58) of the pipette, causes the radial projections (67) of the pipette (8) and corresponding recesses (66) in the outlet housing (54) to produce a torque which in turn drives rotation of the drum (28) within the drum well (27) about the central longitudinal axis (16), moving the outlet housing (54) and corresponding outlet orifice (55), connecting conduit (57) and inlet orifice (56) into the second fluid-flow permitted position, when the drum has reached the maximum extent of rotational movement provided for by the interactions of the arcuate recessed portion (73), projecting spigot (42) and corresponding stopping abutment surfaces (43, 44, 74, 75) of the drum well and drum respectively. In the second, fluid-flow position, the distal orifice (10) of the pipette (8) is now in alignment with the outlet orifice (45) of the drum well (27). As the outlet orifice (45) is connected to the feeder conduit (46), fluid can be withdrawn, for example, by moving a plunger in the pipette in a proximal direction, from the container (2) through the inlet (56) of the outlet housing, through the connecting conduit (57) and out through the outlet housing outlet orifice (55), into the distal intake orifice of the pipette, and thereby into the pipette itself. In this position, the pipette is located in the second end (23) of the opening (21), and is retained against removal by the narrower dimensions of the end (23) which espouse the outer surface (65) of the pipette, and through the provision of an annular rib or ridge (78), extending outwardly from the outer surface (65) of the pipette, which abuts against a distally facing surface of the second end of the proximal opening (21). Such an abutment physically prevents the annular rib or ridge (78) from passing the narrowed dimensions of the second end (23). In order to be able to remove the pipette (8) from the cap assembly (1), it is therefore necessary to move the pipette (8) back into the fluid-flow prevented position. It should be noted that the pipette (8) retains any liquid held therein during this time, unless the user accidentally depresses the plunger in the fluid-flow permitted position, in which case the fluid will flow back into the container (2). The user thus counter rotates the pipette (8) about its own longitudinal axis, causing torque to be generated once again through the complementary engagement interaction of the radial projections of the pipette, and corresponding recesses of the outlet housing. This torque causes the drum (28) to rotate within the well (27) in a reverse direction around the central longitudinal axis (16), following the arcuate path of the recessed portion (73) and coming to a stop in the first, fluid-flow prevented position, once the the drum has reached the maximum extent of rotational movement provided for by the interactions of the arcuate recessed portion (73), projecting spigot (42) and corresponding stopping abutment surfaces (43, 44, 74, 75) of the drum well and drum respectively. Once in the first, fluid-flow prevented position, the pipette (8) can be withdrawn through the first end (22) of the opening (21) and then subsequently used to administer the fluid container there within.