GB2531789A

GB2531789A - Pierce device

Info

Publication number: GB2531789A
Application number: GB1419388.2A
Authority: GB
Inventors: Canner Philip
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2014-10-31
Filing date: 2014-10-31
Publication date: 2016-05-04
Also published as: GB201419388D0

Abstract

A piercing needle 80 for piercing a gas fed device such as an atomiser (10 figure 1). The needle has a chamfered profile. The needle interior passage is shaped to be broader at its base 86 than at its point 84 to facilitate its removal from the gas fed device. A side channel (95 figure 5) may be provided to provide a side gas flow path for gas moving from the inside of the needle to the inside of the gas fed device. The needle tip (102 figure 6) may alternatively be closed and gas flow solely via a side passage (105 figure 6).

Description

Pierce Device The present invention relates to a piercing device. In particular, the present invention relates to a piercing device for a gas driven atomiser cartridge.

A device in the form of a disposable cartridge for atomising liquids into small nano and/or micro sized droplets is disclosed in W02011/082838, the contents of which is incorporated herein by reference in its entirety. The to cartridge of W02011/082838 comprises a nozzle through which a gas flows. The nozzle is in fluidic communication with a reservoir of liquid to be atomised. As the gas flows through the nozzle the liquid is drawn into the gas flow by the Venturi effect. The liquid becomes entrained in the gas flow as small droplets. To reduce the size of the larger liquid droplets produced by this process, the flow of gas and liquid droplets is impacted against a die surface in close proximity to the outlet of the nozzle. The entrained droplets impact the die surface and break up into yet smaller droplets. The smallest droplets flow out of the cartridge with the flow of gas while the largest droplets return to the liquid reservoir, under the action of gravity, to be re-atomised.

Atomised liquids can be used for many purposes. One use is for therapy, for example, by application to the skin or by inhalation. One example is the atomisation of sodium chloride solution for inhalation to assist with the removal of mucus and debris from the lungs. Another example is the atomisation of hyaluronic acid for skin beauty purposes.

The cartridge of W02011/082838 uses an air compressor or gas bottle to provide the required flow of gas to the cartridge. The gas is introduced into the cartridge via a hollow needle which is also used to pierce the base of the cartridge. A schematic view of a prior art needle is shown in Figure 3. The needle 70 comprises a substantially cylindrical tube 71 having a chamfered -2 -end 72 to provide a needle point 74 for piercing the base of the cartridge. In use, gas flows through the needle 70 into the nozzle within the cartridge.

The present invention provides a piercing needle for piercing a gas fed device, the piercing needle comprising a tube having a major axis and having a chamfer at a first end which forms a needle point, the tube further comprising a gas flow inlet at a second opposite end, wherein the second end of the tube has a larger internal area, measured perpendicular to the major axis, than the first end of the tube. In a particular example the tube is substantially frustoconical.

In one example, the piercing needle comprises an opening located proximate the first end of the tube and the first end of the tube may be closed.

The present invention also provides a piercing needle for piercing a gas fed device, the piercing needle comprising a tube having a chamfer at a first end which forms a needle point, the tube further comprising a gas flow inlet at a second opposite end, wherein the tube comprises an opening located proximate the first end. The first end of the tube may be closed.

In another aspect, the present invention provides a gas driven device comprising a piercing needle as claimed in any preceding claim.

The needle of the present invention is, in one example, easier to remove from a gas fed cartridge after use as there is less tendency for the pierced hole in the base of the cartridge to drag along the sides of the needle, In addition, if the opening of the needle becomes blocked with a plug of material from the base of the cartridge as the needle pierces, in some examples, the present invention provides another gas flow path.

Examples of the present invention will now be described with reference to the following figures in which: -3 -Figure 1 shows a schematic diagram of a gas driven atomisation apparatus; Figure 2 shows an example of a gas driven atomiser cartridge; Figure 3 shows a prior art piercing needle; Figure 4 shows a piercing needle according to the present invention; Figure 5 shows an alternative piercing needle according to the present invention; and Figure 6 shows a still further alternative piercing needle according to the present invention.

Referring to Figurel, a gas driven device 10 for atomising a liquid for use in therapy comprises an atomiser 20, a pressure reduction device, such as a gas regulator 30 and a high pressure gas cylinder 40 containing a gas under pressure. The gas in this example is enriched air which comprises in the region of 23% by volume oxygen. However, any suitable gas may be used such as, for example, carbon dioxide, nitrogen or any of the inert gases or any mixture thereof. It will be understood that in this context, the word gas refers to any substance which is in the gaseous phase at standard pressure and temperature. The gas or gas mixture in the high pressure cylinder 40 may be a permanent or non-permanent gas depending on the physical properties of the particular gas or gas mix in question.

It will also be understood that it is common parlance in the art to refer to a pressurised gas container as a gas cylinder and that the high pressure gas cylinder 40 of the present invention need not be cylindrical in shape.

The gas cylinder 40 has an internal pressure in the region of about 200 bar to about 300 bar before use. That is, before the gas cylinder is opened and gas allowed to escape from the cylinder. It will be understood that the cylinder pressure reduces as gas escapes from the cylinder. -4 -

To enable the device 10 to supply gas to the atomiser 20 at the required operating pressure of between about 1.5 bar to about 10 bar, the gas from the gas cylinder 40 passes through a pressure reduction device 30 such as a regulator. If necessary, more than one pressure reduction step may be used such that the pressure reduction device may comprise a plurality of pressure reduction devices in series.

With reference to Figure 2, an example of a gas operated atomiser 21 is shown. Such atomisers are well known in the art. However, for completeness, the basic operation of this type of atomiser is described below.

The atomiser 21 comprises a disposable cartridge 50 having an outer shell 51 which surrounds an internal chamber 52. Within the chamber 52 there is provided a nozzle 53 and a die 54 having a die surface 55. A capillary channel 56 connects an orifice 57 at the top of the nozzle 53 to a reservoir of liquid 58 located at the base of the nozzle 53.

The outer shell 51 is closed at its lower end 59 by a gas inlet cover 60, and at its upper end 61 by an exit seal 62. The gas inlet cover 60 is a pierceable and is pierced, in use, by a hollow needle connected to the gas supply. The exit seal 62 comprises a series of tabs (not shown) which are torn off to provide exit holes for the atomised liquid from the chamber 52. In an alternative example, the exit seal 62 may comprise a screw top or a foil seal or the like. The exit seal 62 may also be arranged to be pierceable.

In use, gas flows in to the cartridge 50 via the gas inlet and flows through the nozzle 53. Liquid 58 is drawn up the capillary tube 56 to the nozzle tip by suction caused by the Venturi effect as the gas flows through the nozzle 53. The liquid 58 becomes entrained in the gas flow as small droplets.

To reduce the size of any relatively large droplets in the fluid stream exiting the nozzle 53, to the nano or micro size range, the fluid flow, -5 -comprising gas and entrained liquid drops, strikes the die surface 55 of the die 54. The liquid droplets break up into nano and micro sized droplets. The largest of the droplets fall back into the liquid reservoir 58 under the influence of gravity, while the smallest of the droplets are carried by the gas flow out of the cartridge 50 via the openings in the exit seal 62.

Figure 4 shows a schematic view of a piercing needle 80 suitable for use with the cartridge 50 described above. The needle 80 comprises a tube 81 having a major axis 87. As shown, the tube 81 is shaped so that the interior area of the tube 81, measured perpendicular to the major axis 87, is greater at its downstream end 86 than at its upstream end 82. In this particular example, the tube 81 is substantially frustoconical in shape.

The upstream end of the tube 81 is chamfered so as to provide a needle point 84 for piercing the inlet cover 60 of the cartridge. In this example, the upstream end 82 of the needle 80 is closed bay an end wall 88. An opening 85 is provided in the tube 81 proximate the upstream end 82 to provide a gas flow path from the interior of the tube 81 to the interior of the cartridge 50, specifically, to the base of the nozzle 53.

In an alternative embodiment, shown in Figure 5, the walls of the tube 91 have a curved profile and the upstream end 92 of the tube 91 is not closed such that there is a gas flow path via both the upstream end 92 and the side opening 95. In this example, the chamfer at the upstream end 92 of the tube has a curved profile. The side opening 95 may be dispensed with if desired such that the only gas flow path from the interior of the needle 90 to the interior of the cartridge is via the upstream end 92 of the needle.

In a yet further example shown in Figure 6, the needle 100 may comprise a generally cylindrically shaped tube 101. An opening 105 is provided in the tube 101 proximate the upstream end 102 and the upstream end 102 of the needle 100 is closed. Alternatively, the upstream end 102 of -6 -the needle 100 may be open such that there are two flow paths from the interior of the needle 100 to the interior of the cartridge in use.

Although straight and curved chamfers are described and shown in relation to the needle variants described above, it will be understood that the chamfer may have any other suitable profile. It will also be understood that the needle point may be formed of a number of chamfers. -7 -

Claims

Claims: 1. A piercing needle for piercing a gas fed device, the piercing needle comprising a tube having a major axis and having a chamfer at a first end which forms a needle point, the tube further comprising a gas flow inlet at a second opposite end, wherein the second end of the tube has a larger internal area, measured perpendicular to the major axis, than the first end of the tube.
2. A piercing needle as claimed in claim 1, further comprising an opening located proximate the first end of the tube.
3. A piercing needle as claimed in claim 2, wherein the first end of the tube is closed.
4. A piercing needle as claimed in any preceding claim, wherein the tube is substantially frustoconical.
5. A piercing needle for piercing a gas fed device, the piercing needle comprising a tube having a chamfer at a first end which forms a needle point, the tube further comprising a gas flow inlet at a second opposite end, wherein the tube comprises an opening located proximate the first end.
6. A piercing needle as claimed in claim 5, wherein the first end of the tube is closed.
7. A gas driven device comprising a piercing needle as claimed in any preceding claim.