WO2015181513A1

WO2015181513A1 - Automatic dispenser

Info

Publication number: WO2015181513A1
Application number: PCT/GB2015/000151
Authority: WO
Inventors: Keith Laidler
Original assignee: Leafgreen Limited
Priority date: 2014-05-30
Filing date: 2015-05-27
Publication date: 2015-12-03
Also published as: GB201409627D0

Abstract

A nozzle arrangement adapted to be fitted to a pressurised vessel or container to permit fluid present in said pressurised vessel or container to be automatically dispensed under pressure over a period of time without the aid of an additional power source such as a battery or electricity, said nozzle arrangement having a body that defines an inlet, an outlet, and an internal fluid flow passageway through which fluid can flow from said inlet to said outlets, said body of the nozzle arrangement having an inlet valve and an outlet valve and a chamber with an inlet and outlet and a means of regulating the flow of fluid into the chamber between two parts that can be manufactured consistently even with variation in manufacturing tolerances of the parts.

Description

Automatic Dispenser

The present invention relates to an outlet device for an aerosol canister or a pressurised vessel. More particularly, but not exclusively, this invention relates to improved nozzle arrangements that are adapted to be fitted to an outlet of an aerosol canister or a pressurised vessel to convert it from a manually operated device into an automatic device.

Nozzle arrangements are commonly used to facilitate the dispensing of various fluids from containers or vessels. For instance, nozzle arrangements are commonly fitted to pressurised fluid filled vessels, devices or containers, such as a so called "aerosol canister", to provide a means by which fluid stored in the vessel or container can be dispensed.

A typical nozzle arrangement comprises an inlet through which fluid accesses the nozzle arrangement, an outlet through which the fluid is dispensed into the external environment, and an internal flow passageway through which fluid can flow from the inlet to the outlet. In addition, conventional nozzle arrangements comprise an actuator means, such as, for example, a manually operated aerosol canister. The operation of the actuator in the active phase means causes fluid to flow from the container to which the arrangement is attached into the inlet of the arrangement, where it flows along the fluid flow passageway to the outlet.

Almost all aerosol canisters are actuated manually by pressing on the actuator but recently automatic aerosol devices have become fairly widespread for products including insecticides, air freshener, air treatments etc. These take many forms but are Usually battery operated and use solenoid valves, timers and sensors to act on the valve of the aerosol canister to cause it to actuate during the day. Refills are supplied for the devices in the form of aerosol cans. Some work on a simple timed device so they spray every 15 to 40 minutes or so whilst others use sensors that detect movement nearby and then release a dosed spray. These devices are expensive to manufacture and are normally sold at a loss and the companies then make high profits on the refill aerosol cans much like ink jet printers are sold at a loss so the companies can make money on the replacement inks.

Whilst this approach works well it would be much better if an automatic device could be made so cheaply that there was no need for refills and the spent aerosol cans could simply be disposed of as normal.

Another problem is that even though the devices are sold at a loss they are still quite expensive and need replacement batteries and this severely restricts sales in developing Countries.

Companies have tried to develop cheap, disposable automatic aerosol cans in the past but nobody has managed to make one that was both cheap and reliable enough as well as being user friendly. Probably the best attempt was tried many years ago with a dosing chamber with a tiny hole as an inlet so the fluid drip fed into the chamber over a preset time of say 15 minutes. The dosing chamber was followed by a precompression valve set so that the fluid could only be released through a spray outlet once a set pressure had been reached. The basic problem with this approach is that no precompression valve works at an exact set pressure and prior to that pressure being reached, the valve will leak. Since the flow into the chamber is extremely slow the pressure in it reaches a certain point and it starts to leak out through the precompression valve so it never actually builds up enough pressure to be able to properly open the precompression valve. Even if it had worked another key problem with this idea is that the aerosol cans reduce in pressure by at least 2 bars over their lifetime and that means that the chamber fills much faster early in the can life than later whereas a more constant time between actuations is preferable. The pressure in the cans also varies enormously with temperature. Another problem is that sprays tend to be of a higher quality and certainly with finer droplets at higher pressures. This system has to restrict the precompression valve to the lowest pressure that the can will have during its lifetime so it is the least effective for the spray quality. The inlet orifice has to be extremely small to generate a very low flow and this is almost certain to block or at least partially block causing the system to either fail or at least to vary the time between discharges.

We solved many of these problems in our invention covered in our patent application PCT/GB2013/000319 some of which is covered here again but we have since made a number of improvements to the technology and this patent application is to cover two of those. A fuller understanding of our technology can be attained from this patent application.

A first problems addressed here is that to make an automatic spray device you need to cause the liquor in the can to controllably leak into a chamber of some sort and this is a very slow leak so you need to create a tiny leak path. This is very difficult to manufacture accurately and it tends to partially or totally block preventing the device from working properly. Yet this has to work reliably, it has to be very low cost and must be made in very large numbers.

A second problem is that the temperature and hence pressure of the gas varies enormously throughout the day and year and around the world and this makes it extremely difficult to make the device to operate at all let alone consistently. As the atmospheric temperature increases the gas expands and so the pressure increases in the canister and this in turn affects the leak rate into the chamber and the amount of movement of the plunger. Since the times are essentially determined by the leak rate and the plunger movement this makes it difficult to regulate the discharge times and volumes. According to a first aspect of the present invention there is provided a nozzle arrangement adapted to be fitted to a pressurised vessel or container to permit fluid present in said pressurised vessel or container to be automatically dispensed under pressure over a period of time without the aid of an additional power source such as a battery or electricity, said nozzle arrangement having a body that defines an inlet, an outlet, and an internal fluid flow passageway through which fluid can flow from said inlet to said outlets, said body of the nozzle arrangement having an inlet valve and an outlet valve and a chamber with an inlet and outlet and a means of regulating the flow of fluid into the chamber between two parts that can be manufactured consistently even with variation in manufacturing tolerances of the parts.

According to a second aspect of the present invention there is provided a nozzle arrangement adapted to be fitted to a pressurised vessel or container to permit fluid present in said pressurised vessel or container to be automatically dispensed under pressure over a period of time without the aid of an additional power source such as a battery or electricity, said nozzle arrangement having a body that defines an inlet, an outlet, and an internal fluid flow passageway through which fluid can flow from said inlet to said outlets, said body of the nozzle arrangement having an inlet valve and an outlet valve and a chamber with an inlet and outlet and a means of regulating the flow of fluid into the chamber where the chamber contains a plunger that moves upstream as the chamber fills and a sealing prodder that seals the outlet from the chamber and the prodder and plunger are connected by a resiliently deformable part such as a spring and an extendable connection that limits the movement of the plunger away from the prodder.

How the invention may be put into practice will now be described by way of example only, in reference to the following drawings in which: Figure 1 is a diagrammatic illustration showing a side view of an example of the engine of a spray through nozzle arrangement for an automatic spray device in the fully compressed state according to the present invention;

Figure 2 is a diagrammatic illustration showing a side view of an example of the engine of a spray through nozzle arrangement for an automatic spray device showing almost the maximum travel of the plunger according to the present invention;

Figure 3 is a diagrammatic illustration showing a side view of another example of a spray through nozzle arrangement for an automatic spray device showing almost the maximum travel of the plunger according to the present invention;

Figure 4 is a diagrammatic illustration showing a side view of an example of the engine of a spray through nozzle arrangement for an automatic spray device in the almost fully compressed state according to the present invention;

Figure 5 is a diagrammatic illustration showing a side view of an example of a leak device according to the present invention;

Figure 1 shows the device with the plunger spring 125 and the prodder spring 121 in the fully compressed state. The leak rate device 104 is in the top of the plunger 102 and this view is enlarged in figure 5. This comprises a plunger 102 with a conically tapered hole 113 leading to an outlet 111 into the lower dosing chamber 112 and a fine threaded section 107 at the upstream end of the plunger 102. A leak part 104 is attached to the plunger 102 via a threaded part 107 that is screwed into a threaded section 106 of the upstream tubular hole 105 of the plunger 102. At the downstream end of the new leak part 104 is a conically tapered post and at the upstream end is a tubular section 123 that holds a filter 109. A hole 114 extends through the top of the leak part 104 to allow the liquor to flow through it into the plunger 102. The fluid flows into the upstream chamber 110 via the inlet filter 101 and channel 115 and through the filter 109 and then the leak part 104 and then into the plunger 105 past the almost seal at 103 through the plunger outlet 111 and finally into the dosing chamber 112. The downstream end of the leak part 104 is screwed down until it almost seals at 103 against the wall of the tubular hole in the plunger. The gap left is the leak path and this determines the rate at which the fluid can enter the dosing chamber 112 which in turn determines the time between discharges. A fine circumferential gap is also created between the leak part 104 and the walls of the plunger chamber at 105 just upstream of the almost seal at 103. The gap isn't much bigger near to the almost seal than the gap in the almost seal and the further upstream the bigger the gap although it is always tiny. This creates a filter for any particulates that get through the upstream filters 109 and 101 and the more particles that are trapped in the gap; the better it acts as an auxiliary filter. This combination of auxiliary prefilters, a fine auxiliary filter and a circumferential leak makes blocking or partial blocking very unlikely. It is however almost impossible to exactly replicate the precise leak rate with plastic mass moulded parts as the impressions will vary slightly as will the mouldings done on different days and with different batches of plastic. So the key is to accept that they will be different and to set them individually during assembly. This is achieved by blowing air through the downstream end of the plunger 111 as the parts are screwed together and fixing the position when the flow records the required rate. Fine threads are required and a fine taper on the tubular hole and plunger is also needed for the very fine adjustments needed. The two parts can also be fixed permanently in position if needed by any number of methods including spot welding or using a locking nut. This isn't ideal either as it makes assembly much more difficult and expensive.

Another version of this could have been achieved with a ball on the rim of a hole in the plunger or even a shaped part on or in a hole. It would have needed another component exerting pressure on the ball or shaped part to cause either to be pushed more or less firmly against the hole or tube wall to vary the flow. The obvious method is to us a threaded part in a threaded section in the plunger like in figure 1 and any means of varying the pressure and mamtaining it thereafter would be sufficient.

Fig 1 also shows a slider pin 117 on the downstream end of the plunger 102 in the prodder 118. Its movement is limited by the plunger annular ledge 119 corning in contact with the prodder ledge 126. As the dosing chamber 112 fills the plunger 102 moves upstream and the slider pin 117 also moves upstream until the annular ledge 119 eventually makes contact with the annular prodder ledge 126 and cannot move any further. The pressure will continue to rise inside the dosing chamber 112 until the prodder 118 is pulled out of the outlet hole 120. Once the seal is broken the force of the prodder spring 121 causes the prodder 118 to move further from the hole 120 until enough fluid has been discharged from the dose chamber 112 when everything returns to the starting position shown. Without the slider pin 117, the plunger 102 goes further upstream when the ambient temperature is higher as this raises the pressure in the can so the time and dose size varies considerably.

Figures 1, 2 and 4 also show a groove 122 in the wall 124 of the dosing chamber 112. This is at or just before the maximum travel of the plunger seal 123 and causes a second leak path into the dosing chamber between the plunger seal 123 and the wall. This maximum travel position is shown in figure 2. There could be a raised ledge or protrusion instead of a groove or even a roughened surface. The point is to increase the flow into the dosing chamber 112 so the chamber quickly fills to the required pressure to enable the prodder 118 to be pulled out of the sealing hole 120. If the groove or equivalent is arranged to be positioned before the maximum travel of the plunger then it will very quickly reach that maximum position.

Figure 3 shows the full view of the device shown in figures 1 and 2 including the actuator button 301 which is pressed down and twisted to lock it into the active or open position. The body part 302 is snapped over the central ring of the aerosol canister which goes into the opening 303 and it is fixed in place by the raised feature 304 that grips onto the underside of the central ring.

Figure 4 shows an extendable connection 401 between the prodder 118 and plunger 102 instead of the sliding pin 117 and it performs the same task causing the prodder 118 to be pulled out of the sealing hole 120 when the extendable connection 401 has reached its maximum position of extension. Normally the extendable connection 401 isn't resiliently deformable or at least only has a minimum resilience although it could be. This is because the prodder spring 121 has to be carefully configured and the accuracy needed is difficult to attain so adding in the complication of an extra plastic spring isn't helpful. This is why the prodder spring 121 itself isn't also used to limit the maximum travel of the plunger 102 as springs become less reliable when fully stretched. Any suitable type of extendable connection will suffice.

We have shown the fluid entering into the dose chamber 112 through a leak device 104 and the plunger 102. It is possible though not as simple, to configure the device so the liquor enters into the dose chamber 112 through the wall 124 of the dose chamber 112 instead but still through a leak device. This arrangement creates a number of difficulties and the plunger seal 123 has to face down stream instead to prevent any liquor from passing it and the main spring 125 has to work the opposite way around so it exerts a downstream pressure on the plunger 102 instead of an upstream pressure. There also needs to be an additional leak path into the chamber that is activated once the plunger 102 has moved far enough upstream as with the current arrangement. But the device then functions substantially the same.

To create a reliable leak arrangement it is a matter of creating a leak path into a chamber of any automatic spray device on a pressurized container that is accurate, consistent, and manufactureable, tends not to block or partially block and is variable to enable the user to control the times between actuations. This is no small problem as the leaks are very tiny and are normally barely a tiny scratch with a triangular groove with sides of around or 0.2 mm or a hole with a diameter of around 0.04 mm. It is only too easy for debris to build up in these partially or fully blocking them. In our first invention we used self cleaning grooves to overcome this problem but it is difficult manufacturing them and they may still partially or totally block. So our answer is to use a cylindrical rod 104 in a tubular hole 113 both preferably made in hard or rigid plastic. There could be a slight taper on the rod 104 or hole 113 or both or the contact area between the two parts could be straight and then upstream of the contact area could be tapered. The rod 104 would normally form an almost seal between it and the wall of the tapered tube 113 but leaving a tiny circumferential gap 105 between the two to create a very slow leak around the circumference of the rod 104. The same gap could be created between the post and rim of the tube 113 rather than inside the tube instead. The leak rate is so tiny that in practice the parts are touching as shown in figure 5 at 103 and the leak happens because it is so difficult to seal two rigid components especially when the contact area is over a length of the parts. In a preferred version the rod 104 has substantially parallel sides for the contact length of the rod and tube of 0.5 - 6 mm and preferably 1- 3 mm and then has a fine taper of 2 - 10 degrees. The tube 113 is also either shaped the same way or more preferably has a very fine taper of 1- 4 degrees and more preferably 1 - 2 degrees for the contact length of the rod 104 and tube 113. In practice, even though the plastic is substantially rigid it gives way so with very fine tapers in the tube 113 the rod 104 forces its way lower down so that there is very little gap between the rod 104 and tube 113 in the contact area and the leaks through happen because of the difficulty of sealing two rigid faces. This is better than having a point seal around the circumference of the interface as it reduces the likelihood of blocking. A similar effect is had when the contact areas in the rod 104 and tube 113 are parallel but this cannot be adjusted for flow during the manufacturing process as there will be no change when the rod 104 is moved down further inside the tube 113. This concept is very different to a standard pin valve.

Normally the surface of the tube 113 and rod 104 are substantially smooth but if one or either is shaped or roughened then instead of a single circumferential leak path there would be a large number of individual leak paths formed between the rod 104 and tube 113. When a vertical groove or hole is used you create one leak route and if this blocks or partially blocks the entire device is adversely affected. But with the rod 104 in tube 113 combination particles have little impact on the overall leak rate. This affect can be further improved by using a tapered or straight rod 104 in a tapered tube 113 so that a circumferential V shaped gap 105 is formed between the rod 104 and tube 113 upstream of the almost seal 103. This is made as a very fine V with tapers on both the tube 113 and rod 104 of around 3 or 4 degrees so that debris that could block off part of the almost seal gets trapped there and the V 105 becomes a filter in its own right as more particles are trapped in it.

The rod 104 in tube 113 is like a pin valve and is well known and used widely but the way we reduce the blocking and vary the flow is different. But the problem with creating such a tiny leak as we need which preferably but not exclusively equates to around 2 - 50 cc of air at 5 bars with plastic moulded parts, is that each moulding can be slightly different and even tiny differences can make an enormous percentage change in the leak flow. The products are used in the mass market where price is critical so tools tend to be made with 32 - 64 impressions and very fast cycle times. So it is virtually impossible to make the leak consistent enough between parts. Our answer is to make the rod 104 with a fine upstream thread 107 and to mount it into a comparable thread 108 on the part 102 with the tubular hole so the rod 104 is screwed into the required position. This isn't so unusual either but we don't attempt to put them into exactly the same position as we know that won't produce consistent results. Instead, during assembly each one is tested and positioned individually whilst measuring the air flow through until each produces the required flow rate. The positions will be the same in some and slightly different in others and that is the key to this solution. Once the position is set the two parts are permanently fixed in position with any suitable method including welding. Now it can tolerate the variations in the parts. So we have a fixed position but that is set during production and each one is potentially different as the rod 104 and tubular hole vary.

Other variations of the idea are possible like a ball or plate on a hole where a part is screwed down onto the ball to plate creating different gaps between the two parts which in turn regulate the leak rate. So it is about bringing two parts together and creating one tiny circumferential gap or a number of tiny gaps and varying their relative positions with a slideable arrangement or threaded parts or equivalent but accepting that they will produce different leaks unless they are set up individually during manufacture with different relative positions. Instead of using screw threads you could use the friction between two parts that are slideably mounted or any other system that enables controlled movement between two parts. The two parts would normally be permanently fixed together after they have been set as well with something like welding, gluing or a snap fit or anything that is suitable for the parts. The preferable solution is the tapered rod in the tapered tubular hole though as it also creates a filter. Preferably, the leak arrangement also has a fine filter immediately upstream of it so as to trap as many particles as possible.

The second problem addressed is that the ambient temperate varies considerably during the day, year and between countries. This means that the pressure in the cans also varies considerably and the distance that the plunger 102 has to move before it will pull out the sealing prodder 118 is dependant on the pressure acting upon it with the higher the pressure the greater the plunger 102 movement required and vice versa. This is because higher pressures mean greater forces acting on the sealing prodder 118 so the prodder spring 121 is stretched further before it exerts enough force on the prodder 118 to counter the pressure on it. But in practice this causes a substantial difference in how far the plunger 102 needs to move before the prodder 118 is pulled out of the sealing hole 120 and that makes the time interval and discharges also vary considerably. In practice with just a connecting spring 121 it is impossible to make the system work across the entire temperate and pressure range that is experienced throughout the World which can be as much as 6 bars difference from the coldest to the hottest temperatures. So if the device is optimised to handle the lowest temperatures then at the higher temperatures there isn't enough force in the prodder spring 121 and main spring 125 to pull the prodder 118 out of the sealing hole 120. If we set the device so the plunger 102 can only go to one position then it cannot work at all of the temperatures it experiences. If there is no spring connecting the prodder 118 and plunger 102, the prodder 118 will just go into a leak mode where a tiny amount of fluid is allowed to be discharged as a leak but not enough to cause a proper discharge. By adding an extendable connection 401 as well as the prodder spring 121 between the plunger 102 and prodder 118 the maximum movement of the plunger 102 is restricted yet it also enables the prodder 118 to be pulled out of the sealing hole 120 by the prodder spring before that position has been reached when the pressures are lower. If the maximum position is reached by the plunger 102 the pressure builds up in the dosing chamber 112 until the main spring can 125 move the plunger 102 up a little further dragging the prodder 118 out of the sealing hole 120 and enabling the prodder 118 to move further upstream as the prodder spring 121 returns to a neutral tension because there is a sudden drop in pressure in the dosing chamber 112 as the fluid escapes through the outlet hole 120. Even with the extendable connection there is still a maximum temperature or pressure that the device will work to but it does mean that it will work within an acceptable temperature and pressure window. It also reduces the amount that the plunger 102 can move which in turn reduces the maximum dose and time so that they are also more acceptable. So the times and doses are similar regardless of the pressure and ambient temperature. The times will be higher with higher pressures as will the times but not by very much.

The extendable connection can be a slideable connection with an extension of the plunger 102 going outside or normally inside of the prodder 118 as shown or with an extension of the prodder 118 going outside or inside of the plunger 102. Or it can be hinged parts or an extendable connection such as a curved lanyard between the plunger 102 and the plunger 102 formed as an integral part of them so that they are just one component. This is the most preferable arrangement as it makes them easier to assemble and cheaper. They are preferably but not necessarily not substantially resiliently deformable as that would impact on the performance of the prodder spring and the action of the prodder spring is critical to the satisfactory performance of the device.

It is possible though much more difficult and less preferable to have the prodder spring 121 downstream of the prodder 118 and upstream of the downstream chamber wall around the sealing outlet hole 120 so it acts between the wall and prodder 118. The spring 121 acts against the prodder 118 being sealed in a similar way to before and once the prodder 118 comes away from the sealing hole 120 the spring 121 pushes it further upstream away from the sealing hole 120. As the chamber 112 discharges fluid the plunger 102 and prodder 118 return and the prodder 118 compresses the prodder spring 121 and seals the outlet sealing hole 120. The problem with this arrangement is that the prodder 118 will remain sealed in the sealing hole 120 at much lower pressures than with the prodder spring 121 acting between the prodder 118 and plunger 102 and also it doesn't seal at lower pressures so the pressure window in which the device will work is greatly reduced.

The problem with the extendable connection is that it can be difficult to make it actually pull out the prodder 118 at all temperatures and pressures and it can still take a long time to activate at the higher pressures because the dosing chamber 112 has to reach higher pressures before the plunger 102 can move to its final position. Also, the dose will be higher at higher pressures because there is more fluid in the dosing chamber 112. Another problem is that the chamber 112 can stay at a balance point with a droplet coming in the chamber 112 and the prodder 118 just moving enough to allow the droplet to escape. So we can arrange for there to be an additional leak path 122 into the chamber 112 at or near to the maximum point of travel of the plunger 102 and this would usually be much faster than the normal leak rate. The easiest way is to have a groove 122 in the side wall 124 of the dosing chamber 112 that the plunger seal 123 meets it at the required position so an additional leak path is created between the two parts. Any way of creating a leak between the seal 123 and wall 124 at the required position is good. As soon as the seal 123 reaches the leak position 122 the liquor will flood into the chamber 112 as the plunger 102 will quickly move to its maximum position and the prodder 118 will be pulled out of the hole 120. There will be no balance position and this is also a good way of helping to balance the hourly discharge.

It is practically extremely difficult to maintain a consistent discharge volume and time interval across a large temperate and pressure range so instead the hourly discharge is kept as constant as possible. If the number of discharges in an hour increases then each discharge volume decreases and vice versa so the actual volume of liquor delivered into a room stays within acceptable limits. This is achieved with the extendable connection and spring arrangement as previously described but it can also be achieved without that provided everything is fully balanced. It is much more difficult and the higher temperatures tend to produce higher discharge volumes but they also take longer. We have accepted that this is very difficult to get around so have elected to produce a similar volume per hour instead. By similar it is preferably within 30%, more preferably within 20% and most preferably within 10%. Normally, companies accept the variation in times and discharges and the hourly discharges vary considerably with ambient temperature. We balance the prodder spring, the main spring, the position where extra fluid is added to the chamber and the maximum travel position to make this possible.

The device has been used on a pressurised canister in the above examples but it could equally be used attached to a mains or pumped fluid or water supply or a device pressurised by hand or any system that delivers fluid under pressure. The applications tend to be insecticide, air freshener and air conditioning, humidifying or cooling but it could also be used in any other application including any air treatment such as adding biocides or antiseptics or it could be used with plants or any other application where a timed spray or discharge is required.

The nozzle arrangement of the present invention may be any suitable form of nozzle arrangement. The nozzle arrangement could be in the form of a spray through cap, which is adapted to be fitted to a standard pressurised aerosol container. Examples of spray through cap nozzle arrangements are again described in International patent Publication WO 97/31841 and WO 01/89958. The nozzle arrangement may be fitted to the pressurised container or device by any suitable means such as, for example, a snap fit mechanism. Anything may be discharged from the aerosol canister as a bolus of liquor, a foam or as an atomised spray. The latter may be produced with a simple orifice or with a standard swirl arrangement and for simplicity will be shown with a simple spray orifice. The actuator means may be of any means that can be operated to selectively open the outlet valve of the pressurised container or vessel. Such actuators are well known in the art. Preferably, the actuator means is a portion of the nozzle arrangement that can be depressed by an operator and fixed in position so as to engage and open the outlet valve and keep it open.

Preferably, the aerosol canister is upright with the device on top of the can or underneath it as described. We will describe a version of one of our own such devices but this patent is directed not just at ours but also any such device that isn't powered by a battery or electricity. We also describe possible versions of shut off valves but any suitable valve will suffice and these are just possible examples.

Throughout where we have shown springs they could easily be replaced with any resiliently deformable part such as a flexible plastic component.

Whereas the invention has been described in relation to what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed arrangements but rather is intended to cover various modifications and equivalent constructions included within the spirit and scope of the invention.

Claims

A nozzle arrangement as in the previous claim where there is a means of controlling the flow of fluid into the chamber such that the controlling means is comprised of two or more parts that create a set leak rate between two of those parts with a gap or gaps between them that may vary due to manufacturing tolerances when assembled but which is set to deliver a set leak rate during the manufacturing process by varying the gap between the two parts until a set flow is recorded and then fixing them in place.

A nozzle arrangement as in the previous claims where the two parts comprise a cylindrical pin in a cylindrical tube.

A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube.

A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube and the pin is substantially cylindrical with a taper of less than 10 degrees. A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube where the tube has a taper of less than 10 degrees.

A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube where the tube has a taper of less than 4 degrees.

A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube where the tube has a taper of less than 4 degrees where the rod and tube form an almost seal.

A nozzle arrangement as in the previous claims where the two parts comprise a shaped pin in a conically tapered tube where the tube has a taper of less than 2 degrees and the rod has parallel sides where the rod and tube form an almost seal.

A nozzle arrangement as in the previous claims where the two parts are joined with a threaded connection so they can be moved relative to each other during assembly to control the leak rate.

A nozzle arrangement as in the claims 1 - 9 where the two parts are joined with a slideable connection so they can be moved relative to each other during assembly to control the leak rate.

A nozzle arrangement as in the previous claims where the two parts have a leak path between them.

A nozzle arrangement as in the previous claims where the leak path is through a circumferential gap or gaps around the rod and formed between the two parts.

A nozzle arrangement as in the claims 1 - 12 where the leak path is caused by the surface of at least one of the parts being uneven.

A nozzle arrangement as in the claims 1 - 12 where the leak path is through more than one hole formed between the two parts.

s A nozzle arrangement as in the previous claims where a ball or plate or any suitably shaped part is used instead of a rod.

A nozzle arrangement as in the previous claims where the ball or plate or any suitably shaped part is on or in a hole.

A nozzle arrangement as in the previous claims where the two parts are positioned together by a third part that is threaded or slideably mounted to control the leak rate.

A nozzle arrangement adapted to be fitted to a pressurised vessel or container to permit fluid present in said pressurised vessel or container to, be automatically dispensed under pressure over a period of time without the aid of an additional power source such as a battery or electricity, said nozzle arrangement having a body that defines an inlet, an outlet, and an internal fluid flow passageway through which fluid can flow from said inlet to said outlets, said body of the nozzle arrangement having an inlet valve and an outlet valve and a chamber with an inlet and outlet and a means of regulating the flow of fluid into the chamber where the chamber contains a plunger that moves upstream as the chamber fills and a sealing prodder that seals the outlet from the chamber and the prodder and plunger are connected by a resiliently deformable part such as a spring and an extendable connection that limits the movement of the plunger away from the prodder.

A nozzle arrangement as in the previous claim where the prodder and plunger are connected by a resiliently deformable part such as a spring and an extendable connection that limits the movement of the plunger away from the prodder.

A nozzle arrangement as in the claims 19 and 20 where the extendable connection is a slideable connection. A nozzle arrangement as in claims 19 and 20 where the extendable connection is resiliently deformable.

A nozzle arrangement as in claims 19, 20 where the extendable connection is deformable.

A nozzle arrangement as in the previous claims where an additional and larger leak path is created at or substantially at the position of maximum travel of the plunger increasing the flow into the chamber.

A nozzle arrangement as in the claims 19 - 24 where the larger leak path extends further down stream of this position but by less than 25% of the distance travelled by the plunger.

A nozzle arrangement as in the claims 19 - 25 where the leak path is formed between the plunger seal and the chamber wall.

A nozzle arrangement as in claims 19 - 26 where the extendable connection moves from a minimum gap position when the chamber is substantially empty to a maximum gap position.

A nozzle arrangement as in the claims 19 - 27 where the prodder is pulled out of the sealing hole when the extendable connection has reached its maximum position and the chamber has reached the required pressure.