Pressurising device for a container and method of use

Abstract

 This invention relates to a pressurising device, suitably for use in pressurising of containers of medicant for animals. According to the invention there is provided a pressurising device (10) for a fluid container (46), the pressurising device comprising a compressible air vessel (14) and connecting means (12) to connect the vessel to the container, characterised in that the connecting means is substantially rigid, and in that the air vessel is mounted directly upon the connecting means. There is also provided a method of using the pressurising device comprising the steps of {i} securing the pressurising device to a container, {ii} holding the pressurising device and container by one hand, and {iii} repeatedly compressing the air vessel to introduce and maintain an excess pressure within the container.

Description

FIELD OF THE INVENTION

[0001] This invention relates to a pressurising device and method of use.

[0002] The invention is expected to find its greatest utility for the pressurising of containers of medicant for animals, and the following description will therefore relate predominantly to such use. However, the use in other applications is not thereby excluded.

BACKGROUND TO THE INVENTION

[0003] Certain types of livestock have been bred to produce meat and/or milk for human consumption. Because of the selective breeding involved in obtaining maximum human benefit from the livestock, the livestock itself can sometimes suffer.

[0004] Dairy cows in particular are nowadays able to produce a vast quantity of milk, considerably in excess of what would naturally be required for its calf or calves to drink. The production of milk by the cow is brought upon by calving, and the sudden increase in milk production at this time is often in excess of what the cow's body can cope with by way of natural hormonal changes. Thus, it is known that cows often succumb to hypocalcemia or "milk fever", which is caused by the rapid depletion of the cow's calcium stores as the calcium is transferred to the milk.

[0005] Hypocalcemia is known often to be a more significant problem with cows on their second and third pregnancies, and is a fatal condition. It is, however, treatable by the rapid introduction of calcium to the cow; the calcium usually being administered in the form of the liquid medicant calcium borogluconate.

[0006] To be effective quickly enough, the calcium borogluconate must be administered subcutaneously or intravenously, and this requires the insertion of a needle into the cow. A container of the medicant may be connected by a flexible conduit to the needle, for the medicant to flow therealong and into the animal.

DESCRIPTION OF THE PRIOR ART

[0007] It is possible to hold the container above the level of the needle and to permit the medicant to flow into the animal by gravity alone. Even if the container is held considerably higher than the level of the needle a 400ml container may take up to 15 minutes to administer in this way, and in some cases up to 800ml of medicant may be required. It is difficult for a person to hold the container up high for such a long time. Also, it is possible that the needle may be indavertently removed from the animal if the animal moves unexpectedly during this time. In addition, such administration may be too slow to save the animal.

[0008] A device for pressurising the medicant container is known, so that the medicant flows under pressure into the animal. With such a device, a 400ml container of medicant can be administered in as little as 2 minutes, and it is no longer necessary to hold the container above the level of the needle. The known device has a compressible ball which is connected by way of a flexible conduit to a stopper fittable into the top of the medicant container. The stopper also carries the delivery tube for delivery of the medicant from the container to the animal. The delivery tube extends to the bottom of the container, and it is necessary to maintain the container substantially upright so that the introduction of air under pressure at the top of the container causes medicant to be expelled from the bottom of the container through the delivery tube.

[0009] A major disadvantage of this device is that a minimum of two people are required to use it (or, rather, a minimum of three hands is required). Thus, one hand is required to hold the needle in the animal (so as to prevent the needle being inadvertently removed should the animal move unexpectedly), a second hand is required to hold the medicant container and ensure that it is maintained upright so as not to inject air into the animal, and a third hand is required to hold and compress the ball to maintain an excess pressure within the container.

[0010] In addition, the device is cumbersome; the two flexible conduits, and the two people using the device, may become entangled if the animal moves around during administration of the medicant.

STATEMENT OF THE INVENTION

[0011] It is the object of the present invention to avoid or reduce the above disadvantages, and to provide a device which can be used by one person working alone.

[0012] According to the invention therefore, there is provided a pressurising device for a fluid container, the pressurising device comprising a compressible air vessel and connecting means to connect the vessel to the container, characterised in that the connecting means is substantially rigid, and in that the air vessel is mounted directly upon the connecting means.

[0013] Since the connecting means is substantially rigid and the air vessel is mounted directly thereupon (rather than the flexible conduit connection of the prior art device), the container and the air vessel can together be held by one hand, the person's other hand holding the needle in the animal.

[0014] Preferably, the connecting means carries a retaining device by which the connecting means and the air vessel may be securely retained upon the container. In this way, the user is not required to hold the container at all, but can instead hold the connecting means and the air vessel, the container being retained in engagement therewith by the retaining means. The user can of course hold the connecting means and air vessel so as to ensure that the container is maintained substantially upright.

[0015] Desirably, the retaining means is a metal clip; desirably also the retaining means is pivotally mounted upon the connecting means. Usefully, the retaining means has a part adapted to locate behind a flange on the container, it being understood that medicant containers typically have a flanged neck.

[0016] Usefully, the connecting means carries a valve means by which the excess pressure may be maintained within the container rather than leak away back into the air vessel. Preferably, the valve means includes a flap valve having a flap which can open to admit the passage of air (into the container), but which closes substantially to prevent the reverse passage of air out of the container.

[0017] Preferably, the air vessel is of plastics material, having a flexible wall of bellows-like construction. Compression of the air vessel acts to close up the bellows and reduce the volume within the vessel. Desirably, the air vessel has an aperture to permit the ingress of fresh air as it expands, the aperture usefully being closed by a part of the user's hand (such as the thumb) during compression of the vessel.

[0018] There is also provided a method of using a pressurising device as herein defined, comprising the steps of {i} securing the pressurising device to a container, {ii} holding the pressurising device and container by one hand, and {iii} repeatedly compressing the air vessel to introduce and maintain an excess pressure within the container.

[0019] The invention is not limited to the use of calcium boragluconate for cows, but could also be used for other medicants and/or dietary supplements, such as magnesium sulphate, dextrose or phosphorus for example, which are often required to be administered quickly to cattle or other ruminants such as sheep and goats.

[0020] It will be understood by those skilled in this art that a substantially constant excess pressure should be maintained within the container. Notwithstanding that an absolutely constant excess pressure is difficult to achieve with devices of this type, it is believed that with practice the repeated compression of the air vessel can be achieved with sufficient accuracy to maintain the excess pressure as constant as is necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Fig.1

is an exploded view of the components making up the pressurising device according to the invention;

Fig.2

is detailed plan and side views of the valve components;

Fig.3

is a plan view of the connector to container sealing washer;

Fig.4

is a plan view of the retaining means;

Fig.5

is a front view of the retaining means; and

Fig.6

is a side view of another embodiment of the device fitted to a medicant container.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In the drawings, similar parts of the differing embodiments carry the same reference numerals.

[0023] The pressurising device 10 comprises a connector 12, an air vessel 14, a valve 16 and a retainer 20.

[0024] The connector 12 is of substantially rigid construction; whilst this may be of rigid plastics material the preferred material is aluminium. The connector 12 has a passageway 22 running through its approximate centre, one end 24 of which is enlarged and threaded so as to receive the cooperating threads 26 of the air vessel 14. In this embodiment the threads of the air vessel 14 and the enlarged end 24 conform to 18mm R4 specification, though other cooperating thread specifications may alternatively be used.

[0025] It will be noted that the threaded part 30 of the enlarged section 24 does not run all the way to the bottom of the enlarged section. This is to provide a small region in which the valve means 16 can lie, without the valve means being clamped or otherwise tightly constrained between the air vessel 14 and the connector 12.

[0026] As better seen in Fig.2, the valve means 16 comprises a washer 30 and a flap valve 32, which lie together at the bottom (as drawn in Fig.1) of the enlarged section 24. The washer 30 has a hole 34 therethrough, and so can allow air to pass in both directions. The flap 36 of the flap valve 32 can seal this hole when the pressure in the container exceeds the pressure in the air vessel 14; however, when the pressure in the air vessel 14 exceeds the pressure in the container (as during compression of the air vessel 14), the flap 36 can be moved away from the hole 34 so that air can flow from the air vessel into the container. In this embodiment the washer 30 is 1mm thick and the flap valve 32 is 0.5 mm thick.

[0027] The container 12 also has a side port 40 through which a flexible delivery tube 42 (Fig.6) may be introduced. The side port 40 is sized so as to provide a seal with the delivery tube, i.e. at the pressures involved air cannot leak between the delivery tube 42 and the port 40. As shown in Fig.6, in use sufficient of the delivery tube 42 is passed through the port 40 so that the open end 44 of the delivery tube lies adjacent the bottom of the container 46 when the container is held upright. The other end of the delivery tube is connected to a needle in known fashion, suitably by way of a Luer slip needle mount.

[0028] Fig.3 shows the sealing washer 50 which in use lies between the connector 12 (specifically between the ledge 52 of the connector) and the neck of the container 46 (Fig.6). In this embodiment the washer 50 is 2mm thick, and is sufficiently compressible to provide a fluid and air tight seal at the pressures involved.

[0029] Pivotably connected to the connector 12 is the retainer 20. As shown in Figs. 4 and 5, the retainer comprises a wire clip having two arms 54 connected to a substantially U-shaped section 56. The U-shaped section is sized to pass around the neck 60 of the container behind the flange 62 thereof. The provision of the retainer as shown allows the connector 12, and thus the air vessel 14, to be securely retained in engagement with the container. In this way, the user can with one hand grasp the connector 12 and use his thumb repeatedly to compress the air vessel. The container can thus be maintained upright by way of its secure engagement to the connector, without the user holding any part thereof.

[0030] It will be understood that the neck of the medicant container 46 shown in the drawings is not threaded, but has a flange adjacent the opening of the neck to which the connector 12 can be secured. In medicant containers which have threaded necks an alternative retaining means could be used if desired. Thus, whilst a retainer similar to the retainer 20 could be adapted to secure the connector to a container with a threaded neck, it might be preferred to utilise a correspondingly threaded connector. Whilst it is understood that an aluminium connector might not be totally suitable for the provision of threads (the threads in time likely becoming damaged by repeated use with the harder threads of a glass container for example), it would be possible to make the connector out of an equally hard or harder material, or to anodise or otherwise coat the connector threads with a hard material so that the threads could withstand often repreated use without significant deterioration.

[0031] The thumb of the user will typically be used to press down upon the upper (in use) surface 28 of the vessel 14, causing the sides of the vessel 14 to be compressed like a concertina and reduce the volume of the vessel, in turn causing air to be forced through the passageway 22 and into the container 46 (Fig.6). The vessel 14 is made of a material sufficiently resilient to ensure that the vessel returns to its rest state (as drawn) when the pressure of the user's thumb has been released. The surface 28 has an opening or hole (not shown), usefully adjacent its centre, to admit air into the vessel during expansion thereof. The hole will be closed and sealed by the user's thumb during compression of the vessel.

[0032] The washer 30 and flap valve 32, the sealing washer 50 and the delivery tube 42 are ideally manufactured from silicone rubber, and thus are suitable for sterilisation in an autoclave. The connector 12 as above indicated is suitably of aluminium and so is also suitable for such sterilisation.

[0033] The air vessel 14 may be susceptible to such sterilisation, but since this does not come into contact with either the medicant or the animal, such may not be necessary and the vessel may suitably be made from a flexible plastics material not necessarily able to withstand the temperatures at which an autoclave operates.

Claims

1. A pressurising device (10) for a fluid container (46), the pressurising device comprising a compressible air vessel (14) and connecting means (12) to connect the vessel to the container, characterised in that the connecting means is substantially rigid, and in that the air vessel is mounted directly upon the connecting means.

2. A pressurising device according to claim 1 in which the connecting means has retaining means (20) by which the connecting means and the air vessel may be securely retained upon the container.

3. A pressurising device according to claim 2 in which the retaining means is a clip, in which the clip is pivotally mounted upon the connecting means, and in which the clip has a part adapted to locate behind a flange on the container.

4. A pressurising device according to claim 2 in which the retaining means comprises a threaded connecting part adapted to cooperate with threads of the container.

5. A pressurising device according to any one of claims 1-4 in which the air vessel is separable from the connecting means.

6. A pressurising device according to any one of claims 1-5 in which the connecting means carries a valve means allowing one-way flow of air.

7. A pressurising device according to claim 6 in which the connecting means has a passageway (22) therethrough, the valve means being loosely constrained within a part of the passageway.

8. A pressurising device according to claim 7 in which the connecting means has port means (40) through which fluid may pass out of the container.

9. A pressurising device according to any one of claims 1-8 in which the air vessel is of plastics material, having a flexible wall of bellows-like construction.

10. A method of using a pressurising device according to any one of claims 1-9, comprising the steps of {i} securing the pressurising device to a container, {ii} holding the pressurising device and container by one hand, and {iii} repeatedly compressing the air vessel to introduce and maintain an excess pressure within the container.

Drawing