WO2009050449A1

WO2009050449A1 - A manual pump dispenser

Info

Publication number: WO2009050449A1
Application number: PCT/GB2008/003487
Authority: WO
Inventors: Keith Laidler; Timothy Rodd
Original assignee: Leafgreen Limited
Priority date: 2007-10-16
Filing date: 2008-10-15
Publication date: 2009-04-23

Abstract

A manually actuated pump dispenser for dispensing a mixture of air and at least one other fluid, the dispenser comprising a final outlet, a cylinder (722), a plunger assembly (714) slidably received in the cylinder to define within the cylinder a main pump chamber (724) of variable volume, a final outlet including an outlet valve arrangement, an air inlet for admitting ambient air into the main pump chamber, wherein the plunger assembly (714) comprises a plunger body and a traveller member (752) mounted to the plunger body within the cylinder, at least part of the traveller member being movable relative to the plunger body to define with the plunger body a fluid dosing chamber (772) of variable volume, a fluid dosing chamber inlet connected to a fluid source and a fluid dosing chamber outlet through which the fluid can be dispensed together with pressurised air from the main pump chamber.

Description

A Manual Pump Dispenser

The present invention relates to a manual pump dispenser for dispensing a fluid product mixed with pressurised air.

It is known to use a manual pump dispenser for dispensing a range of fluid products, such as: perfume, body spray, suntan lotion, insect repellent, lotions, oils, hair spray, antiperspirant, paint and pharmaceuticals. It is also known to provide manual pump dispenser which includes an air pump to pressurise air for mixture with the fluid. The majority of such dispensers are configured for dispensing liquid products but they can be adapted for dispensing a product in powder from. It is known to mix air with liquids in a manual pump dispenser for a number of reasons. Certain products are required to be dispensed as a foam or a mousse and this can be achieved by mixing air with a liquid or gel. Typically, the air/liquid mixture is passed through a fine gauze or filter in the outlet passage. It is also advantageous to mix pressurised air with a liquid product where the product is to be dispensed in the form of an atomised spray. Mixing air with a liquid in this way is known to improve atomisation of the liquid with finer droplets, more control over the droplet size, tighter droplet size distribution, increased throw, less fallout of droplets from the spray and the ability to atomise a broader range of liquids including difficult to atomise liquids such as oils. Known manual air/liquid dispenser pumps typically comprise separate pump chambers for pressurising the air and liquid which are pumped to separate or a common outlet from their respective chambers. This arrangement requires the pressure of the air and the liquid to be balanced throughout the delivery process. The relatively complex nature of the known air/liquid dispensers, when compared to a liquid only dispenser, adds to the cost of manufacture in a market that is extremely cost sensitive. In addition to this, the known air/liquid dispensers have a high actuation force. This combination of factors means that only a relatively few products are provided to consumers in an air/liquid manual pump dispenser, despite the many advantages of mixing air with a liquid in this type of dispenser. There is a need therefore, for an improved manual pump dispenser capable of dispensing a mixture of air and a fluid product which overcomes, or at least mitigates the problems of the prior art dispensers.

In accordance with a first aspect of the invention, there is provided a manually actuated pump dispenser as claimed in claim 1.

Further preferred features of the first aspect of the invention are set out in the claims dependent on claim 1.

In accordance with a second aspect of the invention, there is provided a manually actuated pump dispenser as claimed in claim 55. Further preferred features of the second aspect of the invention are set out in the claims dependent on claim 55.

In accordance with a third aspect of the invention, there is provided a manually actuated pump dispenser as claimed in claim 56.

Further preferred features of the third aspect of the invention are set out in the claims dependent on claim 56.

In accordance with a fourth aspect of the invention, there is provided a manually actuated pump dispenser as claimed in claim 62.

Several embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a first embodiment of a manual pump dispenser in accordance with the invention;

Figures 2 A to 2E are a series of longitudinal cross sectional views through the dispenser of Figure 1, illustrating the operational sequence of the dispenser;

Figure 3 is a longitudinal cross sectional view through a dispenser in accordance with a second embodiment of the invention;

Figure 4 is a longitudinal cross sectional view through a dispenser in accordance with a third embodiment of the invention;

Figure 5 is a longitudinal cross sectional view through a dispenser in accordance with a fourth embodiment of the invention; Figure 6 is longitudinal cross sectional view through a dispenser in accordance with a fifth embodiment of the invention;

Figures 7A and 7B are schematic cross section views of an end cap and outlet valve arrangement forming part of the dispenser of Figure 6, shown the valve in a closed and open configuration respectively;

Figure 8 is longitudinal cross sectional view through a dispenser in accordance with a sixth embodiment of the invention;

Figure 9 is longitudinal cross sectional view through a dispenser in accordance with a seventh embodiment of the invention; Figure 10 is a longitudinal cross sectional view of part of the dispenser in

Figure 9 in an enlarged scale, showing the dispenser with its plunger assembly retracted;

Figure 11 is a view similar to that of Figure 10 but showing the dispenser with its plunger assembly in an inserted position; Figure 12 is a view from the rear of a dispenser in accordance with and eight embodiment of the invention;

Figure 13 is a longitudinal cross sectional view through the dispenser of Figure 12;

Figure 14 is a view similar to that of Figure 13 but in an enlarged scale and showing only an upper/outlet region of the dispenser of Figure 12;

Figure 15 is a view similar top that of Figure 14 but shown a modified version of the dispenser of Figure 12, adapted to spray at 90 degrees to its longitudinal axis;

Figure 16 is a perspective view from one side of a dispenser in accordance with a ninth embodiment of the invention; Figure 17 is a perspective view from one side and towards the front of the dispenser of Figure 16, showing an actuator trigger extended prior to actuation;

Figure 18 is a longitudinal cross sectional view through the dispenser of Figures 16 and 17; Figure 19 is a side elevation showing a dispenser in accordance with a tenth embodiment of the invention;

Figures 20 and 21 are schematic longitudinal cross sectional views through the dispenser of Figure 19, showing the dispenser prior to actuation and in mid actuation respectively;

Figures 22 and 23 are schematic longitudinal cross sectional views through a dispenser in accordance with an eleventh embodiment of the invention, showing the dispenser prior to actuation and in mid actuation respectively;

Figure 24 is a perspective view of a foam dispenser incorporating a manually actuated pump in accordance with the invention;

Figures 25 and 26 are longitudinal views taken on different planes through a foam nozzle for us in a manually actuated pump dispenser in accordance with the invention; and

Figures 27 and 28 are lateral cross sectional views through the nozzle of Figures 25 and 26 taken on lines A-A and B-B of Figure 26 respectively.

In the following description, the same reference numerals but increased by 100 each time will be used to identify features that are the same or which perform the same or similar function in each of the embodiments.

A manual pump dispenser 10 in accordance with the invention comprises a main body 12 and a plunger assembly 14.

The main body 12 has an outer shell or casing 16 and tubular core 18. The interior of the tubular core is divided into two by a wall 20. A larger of the two interior regions of the tubular core 18 forms a pump cylinder 22 which defines together with the plunger assembly 14 a pump chamber 24 of variable volume, as will be described in more detail below.

The smaller of the two interior regions of the tubular core 18 forms an outlet for the dispenser 10, which, in the present embodiment, is configured to dispense a mixture of a fluid product and air as an atomised spray. The outlet in this embodiment includes an insert 26 which is sealingly received within the interior of the tubular core. An axial inner face of the insert defines a stepped circular recess 28 having a first portion 28A and second portion 28B of smaller diameter than the first. A projection 30 extends from an axial outer face of the dividing wall 20 with an end region of the projection locating in the second portion 28B of the recess in the insert with a close fit. References to "axial" or "axially" in the following description refer to the longitudinal axis X of the plunger as indicated in Figure 2B unless otherwise indicated.

The projection 30 has a cylindrical portion 3OA with a frusto-conical tapered portion 30B leading to a free end face 30C. The second portion 28B of the recess in the insert is correspondingly shaped. At least one final outlet nozzle or orifice 38 extends through the insert to fluidly connect the interior of the second portion 28B of the recess with atmosphere. Two or more grooves 40 extend along the outer surface of part of the cylindrical portion 3OA of the projection and into the tapered portion 30B. The free end face 30C of the projection is spaced from the opposing surface of the insert to form a chamber 42 in which the fluid/air mixture is encouraged to spin about the axis of the outlet nozzle. The chamber 42 may be configured as a swirl chamber, for example, or any other equivalent arrangement.

The main body 12 and insert 26 will usually be made from a substantially rigid material. They can be made from any suitable material but are advantageously they are injection moulded from polymeric materials such as polypropylene. The insert may be moulded in the same tool as the main body and connected thereto by a flexible lanyard (not shown) to enable the insert to be positioned in the main body during assembly of the dispenser. The lanyard may be connected to the main body and the insert by frangible link means. In an alternative arrangement, the insert 26 can be manufactured from a relatively flexible material so as to seal effectively with the body 12 and the projection 30 where they contact.

An annular recess 32 is provided in the axial outer face of the dividing wall 20 about the projection 30 so that the dividing wall has a radially outer annular region

2OA of increased thickness. A resiliently deformable annular valve member 34 locates between the axially inner end of the insert 26 and the thicker region 2OA of the dividing wall to form part of a one way, pre-compression outlet valve arrangement for the dispenser, indicted generally at 35. The radially inner face of the valve member 34 contacts and forms a seal with the outer surface of the projection 30 when the valve member is in an initial, resiliently biased position, as shown in Figure 2A.

A number of orifices 36 extend through the dividing wall to fluidly connect the interior of the pump chamber 24 with the recess 32 in the axial outer surface of the dividing wall. With the valve member 34 in its initial resiliently biased position, as shown in Figure 2 A, it sealingly engages the surface of the projection 30 at a point upstream of the position at which the grooves 40 begin so that fluid in the recess 32 is unable to enter the grooves 40 in the projection and the dispenser outlet is closed. The plunger assembly 14 comprises a plunger body 50 and a traveller seal 52 movably mounted to the body 50. The plunger body 50 has a first tubular region 54 having an outer diameter slightly smaller than the inner diameter of the tubular core 18 of the main body and a second tubular region 56 at is axially inner end, the second tubular region 56 having a smaller inner and outer diameter than the first region 52. An annular Hp 58 projects radially outwardly from the free end of the second tubular region 56. The interiors of the first and second tubular regions are fluidly connected and define together a fluid source chamber 59 for holding a reservoir of fluid product to be dispensed. In the present embodiment, the fluid product is a liquid which may be a liquor. The fluid source chamber 59 is closed at the axially inner or downstream end of the second tubular region 56 by a one way valve 60 which may be formed as an integral part of the plunger body. The other end of the fluid source chamber 59 is sealed at the axially outer or upstream end of the first tubular region 54 by means of a follower 62. The follower 62 is inserted into the first tubular region 54 after the fluid source chamber has been filled and is configured so that it can be moved along the first tubular region 54 towards the downstream end but will not move in the reverse direction under normal operating conditions. The follower 62 can be made from any suitable material but is preferably injection moulded from a resiliently deformable polymeric material. The traveller seal 52 is mounted for sliding movement relative to the plunger body 50 and has an annular portion 64 which locates about the outer diameter of the lip 58 on the plunger body. An annular lip 66 projects radially inwardly from an upstream end of the annular portion to engage the outer surface of the second tubular region 56 of the body. The lip 66 also extends radially outwardly to contact the surface of the pump cylinder 22. The lip 66 on the traveller seal locates between the lip 58 on the plunger body and a shoulder 68 at the junction between the first and second tubular regions 54, 56 of the body to limit the axial sliding motion of the of the traveller seal 50 relative to the plunger body.

A circular wall 70 extends laterally to close off the downstream end of the annular portion 64 so that a fluid dosing/dispensing chamber 72 is defined between ^rthe wall 70, the interior of the annular portion 64 and the plunger body 50. An outlet 73 through which fluid can pass from the fluid dosing chamber 72 into the pump chamber 24 is formed by means of an orifice 74 which extends through the centre of the wall 70 and an annular wall 76 which projects into the pump chamber from the wall 70 about the orifice 74. The annular wall 76 sealingly engages about a projection 78 extending into the pump chamber from the dividing wall 20 of the main body to close fluid dosing chamber outlet 73 when the plunger assembly 14 is pushed fully into the pump cylinder 22 as shown in Figure 2A. The wall 70 also extends radially outwardly to contact the inner surface of the pump cylinder.

A resiliency flexible seal member 80 projects from the downstream face of the circular wall 70 to engage with the surface of the pump cylinder 22. The seal member

80 is curved having a concave surface which faces into the pump chamber. The arrangement is such that the seal 80 is forced into close contact with the wall of the cylinder 22 as the plunger is pushed into the cylinder in the direction of arrow A in

Figure 2D. When the plunger is retracted along the cylinder 22 in the direction of arrow B in Figure 2C, the seal member can be deflected away from the surface of the pump cylinder 22 to admit air into the pump chamber 24 from the exterior of the dispenser. In this regard, it should be noted that the Hp 66 and the wall 70 on the traveller do not form an air tight seal with the cylinder wall 22.

The outer end of the plunger body 50 has a ring 82 into which a user can insert their thumb and the casing 16 of the body has two holes 83 for receiving a user's fingers. This arrangement enables a user to push the plunger assembly 14 into the body 12 to actuate the dispenser in the manner of a syringe. Operation of the dispenser 10 will now be described.

Figure 2 A shows the dispenser 10 with the plunger assembly 14 in an inserted position in which it has been pushed as far into the cylinder 22 as it will go. In this position, the traveller seal 52 abuts the dividing wall 20 and pump chamber 24 is at its minimum volume. The lip 58 on the plunger body is in abutment with the wall 70 of the traveller seal so that the fluid dosing chamber 72 is also at its minimum volume.

The projection 78 is engaged in the annular wall 76 of the traveller seal to close the outlet 73 from the fluid dosing chamber 72 to the pump chamber 24 and the dispenser pre-compression outlet valve member 34 is in its resiliently biased closed position closing the dispenser outlet.

To actuate the dispenser 10, a user first retracts the plunger assembly 14 along the pump cylinder 22 in the direction of arrow B. With the projection 78 firmly engaged in the annular wall 76, the frictional resistance between the traveller seal 52 and the dispenser body 12 is greater than that between the traveller seal 52 and the plunger body 50. Accordingly, over an initial range of movement in the direction of arrow B, the plunger body 50 moves relative to the traveller seal, which remains largely stationary, so that the volume of the fluid dosing chamber 72 is increased. Since the outlet 73 from the fluid dosing chamber to the pump chamber 24 is sealed, increasing the volume of the fluid dosing chamber creates a partial vacuum allowing liquid to be drawn into the dosing chamber 72 from the liquid source chamber 59 through the one-way valve 60. As the liquid is drawn into the dosing chamber 72, atmospheric pressure acts on the follower 62 to move the follower along the first tubular portion 54 towards the downstream end. This ensures that no air can enter the liquid source chamber 59 and that the pressure within remains at ambient. Liquid continues to be drawn into the fluid dosing chamber 72 until the lip 58 on the plunger body contacts the lip 66 on the traveller seal. At this point, the fluid dosing chamber is at its maximum volume. Continued movement of the plunger body 50 in the direction of arrow B results in the traveller seal 52 being retracted along the cylinder 22 increasing the volume of the pump chamber 24. With the dispenser pre- compression valve 35 closed, the increasing volume of the pump chamber creates a partial vacuum in the chamber allowing atmospheric air to be drawn into the pump chamber past the seal 80. Whilst the outlet orifice 74 from the fluid dispensing chamber 72 is open at this stage, the orifice 74 is relatively small and air is preferentially drawn into the pump chamber past the seal 80.

Although not shown in the Figures, the plunger body 50 and the dispenser main body 14 each have abutment means which co-operate to limit the movement of the plunger assembly 14 relative to the dispenser body in the direction of arrow B. Figure 2C shows the dispenser with the plunger assembly 14 in a retracted position at which the volume of the pump chamber 24 is at its maximum. At this stage, the pump chamber 24 is full of air and the fluid dosing chamber 72 is full of liquid product. The relative maximum volumes of the pump chamber and the dosing chamber will determine the ratio of air to liquid to be dispensed. It will be appreciated that the relative maximum volumes of the pump and dosing chambers can be selected to determine the ratio of air to liquid as required in any particular application. For example, the ratio of air to liquid can be changed by altering the maximum stroke of the plunger assembly 14. This can be achieved simply by changing the position of the abutment means. Similarly, the volume of liquid to be dispensed can be varied by changing the length of the traveller seal. Thus a range of pump dispensers having different ratios of air to fluid product can be produced using the same basic main body 14 and plunger body 50. The ratio of air to liquid will be at least 3:1 but will typically be 9:1 or more and in many cases will be 40:1 or more. Once the plunger assembly 14 has been fully retracted to charge the main pump and dosing chambers, the user pushes the plunger assembly 14 back into the cylinder 22 towards the inserted position in the direction of arrow A to dispense the liquid product. As the plunger assembly moves in the direction of arrow A, the volume of the pump chamber is reduced, increasing the pressure of the air trapped inside. The increasing air pressure acts on the traveller seal pressing the seal member 80 into contact with the wall of the cylinder to prevent the air escaping past the traveller seal. As a result of the increasing air pressure acting on the traveller seal and the increased rrictional resistance between the traveller seal and the cylinder, the plunger main body 50 moves relative to the traveller seal to reduce the volume of the dosing chamber 72 as shown in Figure 2D. This forces the liquid in the dosing chamber out through the orifice 74 into the pump chamber 24 where it mixes with the air and is further compressed. In the present embodiment, the outlet orifice 74 in the traveller seal is arranged so that the liquid is sprayed into the pump chamber as a fine mist or atomised spray. This helps to mix the liquid with the air and improves the final atomisation when the mixture of air and liquid is dispensed through the outlet nozzle. Whilst it is advantageous for the liquid to be sprayed into the pump chamber 24, the dispenser may be configured so that the liquid enters the pump chamber as a jet rather than a mist or spray.

The liquid continues to be sprayed into the pump chamber 24 until the dosing chamber is empty. During this phase, the plunger assembly continues to move in the direction of arrow A into the cylinder towards the inserted position and the pressure of the air and liquid mixture in the pump chamber is raised. The increasing pressure of the air/liquid mixture is felt on the upstream side of the pre-compression valve member 34, tending to deflect the valve member outwardly. When the pressure of the air/liquid mixture in the pump chamber 24 and the recess 32 reaches a predetermined threshold value above the ambient pressure, the valve member is deflected far enough that a flow path is opened from the recess 32 into the grooves 40. The air/liquid mixture enters the grooves and flows towards and out through the final outlet nozzle 38, where it is dispensed as an atomised spray as illustrated in Figure 2E.

The air/liquid mixture continues to be dispensed as the plunger is pushed in the direction of arrow A, until the plunger assembly reaches the inserted position as shown in Figure 2A. Once the pressure in the pump chamber 24 and recess 32 falls below the threshold value, the valve member 34 will be restored to its closed position to again seal with the outer surface of the projection and close the flow path from the recess 32 to the outlet nozzle 38. In the closed position, the valve member also prevents air or other fluids being drawn back into the pump chamber 24 through the outlet nozzle 38 or from within the grooves 40.

The dispenser 10 can be repeatedly actuated as described above until the follower 62 has moved to the downstream end of the first tubular portion 54 of the plunger body and no further liquid can be drawn into the dosing chamber 72. The dispenser can then either be thrown away or the fluid source chamber re-filled with a fresh charge of liquid. Alternatively, the plunger assembly 14 can be replaced with a similar assembly having a full charge of liquid. The main body 12 could be modified so that it can hold one or more replacement plunger assemblies containing the same or different products.

The valve 35 acts as a one-way pre-compression valve so that the mixture of air and liquid in the pump chamber is only dispensed through the outlet once the pressure in the chamber is sufficiently high to ensure adequate atomisation. The threshold pressure at which the pre-compression outlet valve 35 opens can be varied to suit the application but will usually be between 0.01 MPa (1 bar) and 0.8 MPa (8 bar). The pre-compression outlet valve can be modified in a number of ways so that it opens at the desired threshold pressure. For example, hardness of the valve member can be varied and/or the distance by which it must be deflected to open the outlet flow path. The valve member can be formed as a separate washer as shown or it could be formed integrally with the insert 26. The combined insert 26 and valve member 34 could be formed as a bi-injection moulding from one or more polymeric materials. Furthermore, any suitable design of pre-compression outlet valve can be used as appropriate.

It can be seen that the dispenser 10 provides a simple and effective manual pump dispenser for dispensing an air/liquid mixture. Because the dispenser has a single pump chamber, the design is greatly simplified compared with the known dual chamber arrangements and the size of the dispenser can be greatly reduced when compared with the prior art. The use of a syringe like plunger arrangement means that an acceptable actuation force can be achieved.

An important consideration with this type of mechanical pump dispenser is to ensure that the air and liquid are mixed thoroughly prior to being dispensed. If proper mixing is not achieved the liquid and air can be dispensed separately negating the benefits of using air. To aid in proper mixing of the air and liquid, there will typically be four or five orifices 36 spread about the dividing wall 20 to ensure that that the air and liquid are extracted from the pump chamber 24 simultaneously. The wall 20 may be curved so that the orifices 36 are on different planes and draw from different longitudinal positions inside the pump chamber. The orifices may also be angled or other arrangements provided to cause the fluid flowing through the orifices to spin in the recess 32 to aid mixing. Further mixing chambers can be provided in the flow path to the dispenser outlet. The pre-compression outlet valve 35 and/or the insert 26 and projector 30 may be configured to cause the fluid to spin as it flows from the recess 32 to the dispenser outlet 38 to further aid in mixing. In addition, any of the spray manipulation features disclosed in WO 0189958 may be incorporated to assist in mixing the air and liquid. This is true for all the embodiments disclosed herein where the dispenser is adapted to produce a spray.

The dispenser 10 can be modified in various ways. For example, rather than having a follower 62 in the fluid source chamber 59, at least one wall of the chamber 59 could be flexible so that the chamber collapses as the fluid is drawn out. In a further alternative, a dip tube can be used with an air leak valve to admit air into the fluid source chamber or separate plastic container as the liquid is used up. For certain applications, no dip tube or plunger need be used and the inlet into the dosing chamber would be provided with a flap type one-way valve. In this arrangement the dispenser 10 would have to be used with the dispenser outlet at the bottom so that the liquid in the fluid source chamber 59 sits in the downstream end of the chamber 59. In a further modification, the dispenser outlet 38 need not be aligned with the longitudinal axis but could be offset or angled to dispense the fluid in any desired direction. For example the outlet 38 may be angled to dispense the fluid at substantially 90 degrees to the longitudinal axis.

Figure 3 illustrates a dispenser 110 in accordance with the invention that has a dual chamber arrangement for dispensing two liquid products.

The dispenser 100 essentially comprises two pump chambers 124, 124' and plunger assemblies 114, 114' as described above with reference to the first embodiment arranged side by side. The outlets 136, 136' of both pump chambers are directed into a common final dispenser outlet nozzle 138 via a common pre- compression outlet valve 135. This arrangement ensures that both chambers are opened at the same time during the dispensing cycle. The two pump chambers and their plunger assemblies operate in a similar manner to that described above in relation to the first embodiment.

The ratios of the two liquids and air in the final spray is determined by the relative volumes of the two pump chambers 124, 124' and the two fluid dosing chambers 172, 172'. In the embodiment shown in Figure 3, the two pump chambers 124, 124' and the corresponding plunger assemblies 114, 114' have different diameters but it will be appreciated that this need not be the case.

In the embodiment shown in Figure 3, the inlets from the fluid source chambers 159, 159' into the dosing chambers 172, 172' are simple orifices 160, 160 with no one-way valves. The orifices 160, 160'are off-set from the outlet orifices 174, 174' of the dosing chambers so that when the liquids have been ejected from the dosing chambers, the orifices 160, 160' are closed by their respective traveller seal 152, 152' as shown. This ensures that as the pressure in the pump chamber increases just prior to the pre-compression outlet valve opening, the fluid pressure is not transferred into the fluid source chambers 159, 159' and prevents any risk of the followers 162, 162' being pushed back out of their respective fluid source chambers and improves the traveller outlet seal. The dispenser 10 described above can be modified to use a similar arrangement rather than a one-way valve as desired or the present embodiment can be modified to incorporate a one-way valve. During the early stages of the insertion stroke of the plunger assemblies 114,

114', as the plungers move inwardly in the direction of arrow A towards the inserted position, the liquids in the dosing chambers will flow preferentially through the dosing chamber outlet orifices 174, 174' which are larger than the respective orifices 160, 160'between the fluid source chambers and the dosing chambers. An alternative embodiment of a dispenser 200 for dispensing two liquids mixed with air is shown in Figure 4. In this embodiment there is only one pump chamber 224 and plunger assembly 214 which operates substantially as described above in relation to the first embodiment. A second fluid source chamber 259' is provided in the main body 212 surrounding the tubular core 218 for holding a second liquid. The second fluid source chamber 259' is fluidly connected with the pump chamber 224 by means of a second fluid inlet passage 284.

The dispenser 210 has modified pre-compression outlet valve member 234 with a first seal member 234A which extends into the second fluid inlet passage 284.

The first seal member 234A is arranged to open the passageway and admit the second liquid into, the pump chamber when the plunger assembly 214 is being retracted and to close the passageway 284 when the plunger assembly is being pushed back in towards the inserted position to pressurise the air/liquid in the pump chamber.

In this embodiment, air is drawn into the pump chamber through an air inlet passage 286 in the body. A second seal member 234B on the pre-compression valve member extends into the air inlet passage and is arranged to open the passage to admit air into the pump chamber 224 as the plunger assembly is retracted and to close the passage as the plunger assembly is moved back in towards the inserted position to pressurise the air/liquid mixture in the pump chamber.

Operation of the third embodiment 210 will now be described. With the plunger assembly 214 in the inserted position, the plunger body 250 is retracted. As described in relation to the first embodiment, initial movement of the plunger body 250 relative to the traveller seal 252 causes a first liquid to be drawn into the dosing chamber 272 from first fluid source chamber 259. Once the relative movement between the plunger body 250 and the traveller seal 252 has been taken up, continued retraction of the plunger body moves the traveller seal along the pump cylinder 222 increasing the volume of the pump chamber. As the pressure in the pump chamber falls below atmospheric, the seals 234A and 234B open to allow the second liquid to be drawn into the pump chamber from the second fluid source chamber 259' and air to be drawn into pump chamber through the air inlet passage 286. The relative sizes of the second fluid inlet passage 284 and the air inlet passage 286 determine the relative volumes of air and second liquid that are drawn in.

Once the plunger assembly 214 has been fully withdrawn to the retracted position, it is pushed back towards the inserted position to dispense the liquids. As the plunger moves back towards the inserted position, the increasing pressure of the air/second liquid in the pump chamber closes the first and second seal members 234A and 234B and the plunger body 250 moves relative to the traveller seal 252 to force the first liquid out of the dosing chamber 272 into the pump chamber, where it mixes with the second liquid and the air. As the plunger assembly continues towards the inserted position, the pressure of the air/liquid in the pump chamber continues to rise and the fluid dosing chamber is emptied. Once the pressure of the air/liquid in the pump chamber 224 reaches the threshold valve above atmospheric, the pre- compression outlet valve 235 opens and the mixture of air and the two liquids is dispensed through the outlet nozzle 238 as an atomised spray.

For some applications, it may be desirable to produce a dispenser which does not use a traveller seal and dosing chamber arrangement for introducing a liquid into the pump chamber. One way of achieving this would be replace the plunger assembly

214 in the dispenser 210 by a plunger having no fluid source chamber and a static seal. The plunger might be similar to the type of plunger used in a syringe, having a solid plunger body. With this arrangement, a single liquid would be stored in the outer liquid chamber 259' and drawn into the pump chamber 224 together with a charge of air when the plunger is retracted. The air and liquid would then be dispensed together when the plunger is pushed into the chamber and the pre-compression outlet valve is opened.

Rather than a single annular fluid source chamber 259' extending around the pump chamber 224, there could be several fluid source chambers in the body, each being fluidly connected to the pump chamber via a one-way valve. In a further modification, the fluid source chamber 259' could be provided adjacent the pump cylinder 222 rather than surrounding it. This arrangement could look similar to the dispenser 110 in accordance with the second embodiment, except there would be only one plunger assembly 114 in one of the cylinders 122. The other cylinder 122' would be adapted to form a fluid source chamber with a follower and would be connected to the pump chamber via a fluid passage and a one-way valve. The plunger assembly in this case would not have a traveller seal or fluid source chamber.

The preferred embodiments described above are all actuated in the manner of a syringe, which is a simple and easy to manufacture solution. However, for some applications it may be preferable for the dispenser to include actuation means such as a trigger, leaver or button similar to those used in conventional pump dispensers. Any of the dispensers described herein could be modified into an actuator operated device by adding an actuating mechanism. Advantageously, the actuator would be provided as an integral part of either the main body case or the plunger body so that no additional separate components are required. The use of an actuator mechanism provides a superior mechanical advantage and could be used to bias the plunger assembly to the retracted or inserted position. This would provide a pump action that is more like that of a Standard dispenser pump and would allow larger volumes of liquid to be delivered. An example is shown in Figure 5, which illustrates a fourth embodiment of a dispenser 310 in accordance with the invention.

In the fourth embodiment, the main body 312 and the plunger body 350 are formed as an integral component and linked by means of a resilient arm 383 which acts as a spring the retract the plunger assembly 314 and as an actuator portion that can be depressed to push the plunger assembly to the inserted position.

The main body portion 312 has a shortened tubular core 318 which projects internally to define the pump chamber cylinder 322. The exterior surface of the main body portion is recessed at 390 to receive an insert 326 which locates about a projection 330 to define an outlet for the dispenser in a manner similar to the previous embodiments. However, in this embodiment, the valve member 334 of the pre- compression outlet valve 335 is mounted internally at the downstream end of the pump chamber 324. Thus a further projection 378 extends from the wall 320 of the casing into the pump chamber 324. The free end of the projection 378 is tapered and is adapted to locate in and seal the outlet orifice 374 in the traveller seal 352 when the plunger assembly 314 is fully inserted into the pump cylinder, in a manner similar to the previous embodiments. The projection 378 in this case is longer than in previous embodiments and the pre-compression valve member 334 is located in a recess at the downstream end of the pump chamber 324 so that its inner annular face contacts and forms a seal with the internal projection 378 when in its initial resiliently biased position. This prevents fluid in the pump chamber travelling past the valve member to reach outlet orifices 391 in the casing wall 320 which fluidly connected with grooves 340 in the external projection 330 and the outlet nozzle 338. When the pressure of the fluid in the pump chamber 324 reaches the desired threshold value above atmospheric, the valve member is deflected upwardly to open a flow path through the outlet nozzle 338.

The plunger body 350 comprises a first, downstream portion 392 which is dimensioned to fit within the pump cylinder 322 and a second, upstream portion 393 having a larger diameter. This arrangement enables the fluid source chamber 359 to hold a larger volume of liquid with out increasing the overall length of the dispenser and could be applied to any of the embodiments described herein. The traveller seal 352 is mounted to the first portion 392 for limited relative movement in a manner similar to the previously described embodiments.

The dispenser 310 operates in the same basic way as the previously described embodiments, except that the plunger assembly 314 is biased to the retracted position by the arm 383 after each actuation. This means that a user need simply press the plunger assembly inwardly to the inserted position to actuate the spray. Once the user releases the plunger assembly it is automatically biased to the retracted position. Cooperating stop members 394, 395 on the main body 312 and the plunger body 350 prevent the plunger assembly being pulled out of the chamber cylinder 322 and control the stroke of the plunger.

The other difference between this and the previous embodiments is that the outlet orifice 374 from the dosing chamber into the pump chamber is relatively large and the projection 378 engages in the orifice itself when the plunger is fully inserted.

Advantageously, the combined main/plunger body will be injection moulded as a one-piece component from one or more polymeric materials. When the component is moulded, the plunger body portion 350 will typically be twisted through 180 degrees from the position shown, so as to be outside of the casing part of the main body portion. During assembly, the plunger portion is inserted into the casing after the traveller seal 252 has been fitted. Having the plunger assembly 314 biased to the retracted position may be desirable for users who do not wish to have to manually retract the plunger assembly prior to actuating the dispenser. It is also advantageous as it ensures the plunger assembly is fully retracted and that a full dose of liquid and air are delivered each time. This may be particularly desirable for pharmaceutical applications. It will be appreciated that a spring or other arrangement for biasing the plunger assembly or assemblies to the retracted position can be used in any of the embodiments disclosed herein. For example, a spring can be arranged to operate between the plunger body and the main body of the dispenser. Alternatively, the plunger assembly or assemblies could be biased to the inserted position so that a user only has to retract the plunger assembly or assemblies and release them to actuate the dispenser. Figure 5 illustrates a dispenser 310 in which the plunger 314 has smaller diameter portion 314a, which enters the pump cylinder 322, and a larger diameter portion314b, which remains outside the pump cylinder. This arrangement allows the plunger to hold an increased volume of liquid without increasing the actuation force, which is determined by the cross sectional area of the portion of the plunger which enters the cylinder to compress the air/liquid. The portion of the plunger 314b that does not enter the cylinder need not be cylindrical and could extend laterally rather than longitudinally if desired. In a modification, which could be adopted in this or in any other of the embodiments described, the larger diameter portion of the plunger could be formed by a conventional bottle on to which is mounted plunger head which carries the traveller seal and which is received in the pump cylinder. The bottle would have dip tube and an air leak valve would be provided to allow air to enter the bottle as the liquid is used up. With this arrangement, it may be convenient to move the dispenser body and cylinder relative to the bottle to actuate the dispenser. A fifth embodiment of a dispenser 410 in accordance with the invention is illustrated in Figures 6, 7 A & 7B.

The dispenser 410 is generally similar in construction and operation to the embodiments previously described. The dispenser 410, differs from the previous embodiments in that the outlet 473 from the fluid dosing chamber 472 into the pump chamber 424 incorporates a one way fart or bird beak valve 474a. The valve 474a is configured to open and allow liquid to enter the pump chamber 424 from the fluid dosing chamber 472 when the pressure in the fluid dosing chamber is higher than that in the pump chamber and to close when the pressure in the pump chamber 424 is higher than that in the dosing chamber 472. The fart valve is a known design, which comprises a flexible valve member having a very fine slit that tends to close. When the fluid dosing chamber is being compressed to expel the liquid into the pump chamber, the pressure of the liquid acting on the inner surface of the valve member opens the slit so that the liquid can pass into the pump chamber as a spray. When the pressure in the liquid chamber falls, the pressure in the pump chamber acting on the valve member closes the stilt preventing fluid from passing back from the pump chamber into the fluid dosing chamber. The valve 474a is advantageously formed as part of the traveller seal 452 but could be provided as a separate component. Whilst a fart valve arrangement is advantageous, any suitable one-way valve could be used.

One advantage of using a one-way valve at the outlet 473 of the traveller seal is that the arrangement is not reliant on the user pushing the plunger fully into the cylinder 422 to seal the outlet as with the previously described embodiments.

The other main difference between the fifth embodiment 410 and the previous embodiments is the construction of the dispenser outlet, hi the fifth embodiment 410, the outlet nozzle 438 is provided as part of an end cap 490, which is removably mounted to a downstream end of body 412 by means of a screw thread or other quick fit arrangement. A seal member 490a is provided between the body and the cap to prevent fluids escaping through the gap between the cap 490 and the body 412.

As can be seen best in Figures 7A and 7B, the downstream end of the pump chamber 424 is closed by means of a plate 420 which is trapped between the end cap 490 and the body 412. One or more orifices 436 extend through the plate to admit fluid to a space 491 between the wall and the base of the end cap.

The cap 490 has a nozzle portion 492 with a central bore 493 leading to the outlet 438. The bore 493 is connected by two or more further fluid passageways 494 with an annular recess 495 in the bass of the cap. A pre-compression outlet valve member 434 is mounted to the cap to control the flow of fluid into the recess 495. The valve member 434 has a central spigot 434a, which locates in a bind bore 496 in the base of the end cap and a resiliently flexible disc portion 434b. hi its initial resiliently biased position, as shown in Figure 7A, the outer periphery of the disc portion engages with a corresponding seal surface 497 on the end cap to close the flow path from the space 491 into the recess 495 and the outlet flow passageways 494. During the dispensing phase of operation, the increasing fluid pressure in the pump chamber 424 and the space 491 acts on the disc portion 434b deflecting it upwardly as shown in Figure 7B. The pre-compression valve 435 is configured so that the disc portion 434b is deflected sufficiently to open a flow path into the recess 495 and the outlet passageways 494 when the pressure of the fluid reaches a desired threshold value above atmospheric. Figure 8 shows a modified version 510 of the dispenser 410 described above.

In this embodiment, the plate 520 is displaced inwardly from the base of the end cap

590 to create a chamber 598 for receiving an insert (not shown) containing a powder or liquid product. The insert may be a capsule, sachet or bag and is placed in the chamber by removing the end cap 590. The insert has holes so that as air passes through the chamber 598 to the outlet 538, the contents of the insert is entrained with the airflow. The holes in the insert are configured so that the product can be forced out when pressurised air is moved through the chamber 598 but is held in the insert at other times. The plate 520 in this embodiment has a plurality of orifices 536 through which the air can enter the inset chamber 598.

The dispenser 510 may have a fluid source chamber 559 in the plunger assembly 514 for a first product that is delivered as described above in relation to the previous embodiment and which mixes with the second product in the insert as it flows through the chamber 598. Alternatively, the insert may contain the only product to be delivered, in which case the plunger assembly 514 may be a conventional solid plunger which simply pressurises the air. Normally, the dispenser 510 would have a pre-compression outlet valve 535 but the dispenser can be configured with no outlet pre-compression valve.

The dispenser 510 in is particularly suitable for use in dispensing pharmaceutical products such as nasal sprays or throat powders.

In all the embodiments described above, a mechanism is provided to seal the outlet of the traveller seal, at least when the plunger assembly is at the inserted position, so that air is not drawn into the fluid dosing chamber when the plunger is retracted. In an alternative arrangement, the dosing chamber outlet need not be sealed so that a small amount of air is allowed to enter the fluid dosing chamber. In this case, the volume of the dosing chamber can be increased to compensate and to ensure that the desired volume of liquid is accommodated. In a further alternative, the inlet into the fluid dosing chamber can be made significantly larger than the outlet so that the liquid is preferentially drawn into the dosing chamber. Whilst it is advantageous for the traveller seal 52, 152, 252, 352, 452 to be mounted for sliding movement relative to the plunger body, other arrangements can be used. For example, the traveller seal can be made of a resiliently flexible material and fixed relative to the plunger body. In this case, the traveller seal would collapse as the plunger assembly is pushed into the pump cylinder to force the liquid into the pump chamber. When the plunger assembly reaches the inserted position, the traveller seal may co-operate with a pin to seal the dosing chamber outlet as with the previous embodiments. The arrangement being such that a downstream portion of the traveller seal is held stationary as the plunger is initially retracted until the dosing chamber has reformed and liquid drawn into the dosing chamber. The traveller seal could be formed as a flexible dome, bellows or rolling diaphragm, for example. Figures 9 to 11 illustrate a further embodiment 610 of a dispenser in accordance of in invention in which the traveller seal 652 is in the form of a rolling diaphragm. This embodiment also illustrates an alternative outlet arrangement for the pump chamber which is designed to ensure the fluid and air mix thoroughly.

As with previous embodiments, the dispenser 610 has a body 612 which defines a cylinder 622 into which a plunger assembly 614is inserted. The plunger assembly 614 includes a rigid plunger body 650 and to which is mounted a resiliently flexible traveller seal 652. The plunger body 650 comprises a tubular portion 650a and a ring portion 682. The tubular portion 650a is closed off at its axially inner/upstream end by a wall 668 and defines a cylindrical fluid source chamber 659 for holding a reservoir of fluid product to be dispensed. The axially outer/downstream end of the tubular portion 650a is sealed by means of a follower 662 after fluid has been introduced into the fluid source chamber.

An annular flange 656 projects into the pump chamber from the outer surface of the wall 668 to mount the traveller seal 652. In this embodiment, the traveller seal does not slide relative to the plunger body 650 and the annular flange 656 has a tapered portion 656a which projects radially outwardly to be received in a correspondingly shaped recess in a main body portion of the traveller seal to locate the seal firmly on the end of the plunger body. The traveller seal 652 has a resiliently flexible rolling diaphragm portion 652a and a tubular spout 652b which projects axially into the pump chamber 624. The axially inner or upstream end of the tubular spout 652b is closed by a one way bird beak valve 674a which controls the release of fluid from the fluid dosing chamber. A fluid dosing chamber 672 of variable volume is defined between the rolling diaphragm 652a, the tubular spout 652b, the annular flange 656 and the wall 668.

A spigot 668a projects into the fluid dosing chamber 672. A bore 668b extends through the wall and the spigot to fluidly connect the fluid source chamber 659 with the fluid dosing chamber 672.

The traveller seal 652 comprises a seal member 680 which engages the surface of the cylinder 622. The seal member 680 is constructed and operates in a similar manner to seal member 80 described above in relation to the first embodiment. Thus the seal member 680 permits air to be drawn into the pump chamber 624 past the seal member 680 when the plunger assembly 614 is retracted and is biased into sealing contact with the cylinder 622 to prevent air moving out of the pump chamber past the seal member 680 when the plunger assembly is inserted.

Whilst it is advantageous to use a single integral component such as the traveller seal 652 to seal the plunger assembly in the cylinder 622 and to form the fluid dosing chamber 672, it will be appreciated that the seal member 680 could be provided as a separate component from the rolling diaphragm 652a and the tubular spout 652b if desired. Where the seal is provided as a separate component, the traveller seal 652 would comprise the rolling diaphragm and the tubular spout and may be referred to as a traveller member. The same is true for all the embodiments disclosed herein wherein the sealing function could be carried out by a separate component from that used to form the fluid dosing chamber.

An end cap 690 is removably mounted to the downstream end of the dispenser body, which in this case also closes off the downstream end of the pump chamber. An outlet stem 692 projects axially from the outer surface of the cap 690. A central bore 693 extends through the outlet stem to connect the pump chamber outlet with a final dispenser outlet in the nozzle. Although not shown, an aerosol nozzle having a final dispenser outlet orifice will usually be mounted to the free end of the outlet stem as is known in the art. Alternatively, a nozzle may be formed using an insert similar to the insert 26 described in relation to the first embodiment. In the present case, the nozzle would be adapted to dispense the mixture of air and another fluid as an atomised spray. However, in other embodiments, the stem could be adapted so that the outlet end 638 of the bore 693 is the final dispenser, outlet. The inner surface of the cap 690 includes a central tubular portion 690b which projects into the pump chamber and is dimensioned to receive the tubular spout 652b on the traveller seal. The tubular portion 690b defines a blind bore 690c which extends into the main body of the cap. A spigot 69Od having an outer diameter smaller than the bore 690c projects into the bore 690c. The fluid outlet bore 693 extends through the spigot 69Od. Surrounding the tubular portion 690b is a tapered shoulder 69Oe having an annular recess 69Of with a curved base for receiving a shoulder region of the rolling diaphragm 652a.

A resiliently flexible outlet valve member 634 is located within the blind bore 690c in the cap body and tubular portion about the spigot 69Od. The valve member 634 is generally tubular and has a base 634a which firmly locates in the annular spaced between the spigot 69Od and the inner wall of the bore 690c to hold the valve member in place. The valve member has a tubular portion 634b which abuts the inner surface of the tubular portion 690b of cap over part of its length. The tubular portion 634b is connected to the base 634a by means of a resiliently deformable region 634c which enables the tubular portion 634b to be moved upwardly, as shown, about the spigot 69Od. The valve member has a bird beak valve 634d which locates about the end of the spigot 69Od. In it's initially resiliently biased state, the bird beak valve 634d closes about the end of the spigot to prevent fluid entering the bore 693 from the pump chamber 624 and also preventing fluid being drawn into the pump chamber 624 through the bore. As will be described in more detail below, when the plunger assembly 614 is pushed into the body 612 to actuate the dispenser, the tubular spout 652b on the traveller seal enters the tubular portion 690b of the cap and eventually abuts the tubular portion 634b of the outlet valve member pushing the valve member 634 onto the spigot and opening the bird beak valve 634d, as shown in Figure 11.

Grooves 69Og and 634e extend along the inner surfaces of the tubular portion

690b of the cap and the tubular portion 634b of the outlet valve member respectively to enable air within the pump chamber to enter the tubular portion 634b of the valve member when the tubular spout 652b of the traveller seal is engaged within the tubular portion 690b of the cap.

Operation of the dispenser 610 will now be described. With the plunger assembly 614 in a retracted position as shown in Figures 9 and 10, the pump chamber 624 is fully charged with air and the fluid dosing chamber

672 is fully charged with a fluid product such as a liquid or liquor to be dispensed.

The valves 634d and 674a on the outlet valve member and the traveller seal 652 respectively are both closed.

As the user pushes the plunger assembly 614 into the body towards the inserted position, the volume of the pump chamber 624 is reduced raising the pressure of the air inside the chamber. The increasing air pressure inside the pump chamber acts on the inner surface of the valve member 680 pressing it into contact with the wall of the cylinder 622 ensuring a good air tight seal. The increasing air pressure also acts on the liquid in the dosing chamber 672 through the flexible rolling diaphragm 652a causing a corresponding increase in the pressure of the liquid in the dosing chamber 672. However, as liquid is relatively incompressible, the rolling diaphragm 652a is not deflected and the volume of the fluid dosing chamber remains substantially constant.

The pressure of the air in the pump chamber 624 and the liquid in the dosing chamber 672 continues to rise as the plunger assembly is inserted and eventually the tubular spout 652b enters the tubular portion 690b of the cap.

Figure 10 shows the dispenser with the spout 652b having entered the tubular portion 690b, which is received in an annular gap between the tubular spout 652b and an inner wall of the rolling diaphragm 652a. As shown, the downstream end of the spout 652b contacts the upstream end of the tubular portion 634b of the outlet valve member 634, pushing the outlet valve member 634 onto the spigot 69Od opening the bird valve 634d. With the outlet valve 634d open, air is able to enter the outlet bore 693 and be dispensed through the outlet orifice 638.

As the spout 652b enters the tubular portion, the inner wall of the rolling diaphragm contacts the outer wall of the tubular portion 690b of the cap and an annular ridge 652c on the inner wall enters a groove 69Oh on the outer surface of the tubular portion 690b. Further inward movement of the plunger assembly 614 results in the rolling diaphragm 652 being be compressed, reducing the volume of the fluid dosing chamber and further pressurising the liquid inside. The increased pressure of the liquid in the dosing chamber forces the bird beak valve 674a on the end of the spout to open and liquid is sprayed into the tubular portion 634b of the outlet valve member where it mixes with the pressurised air and is dispensed through the outlet bore 693 and the outlet orifice 638. Further air is able to enter tubular portion 634b of the outlet valve member 634 through the grooves 69Og and 634e in the tubular portion of the cap and the tubular portion of the valve member respectively.

As the rolling diaphragm 652a is deflected to dispense the liquid, the inner wall of the diaphragm is received inside the annular flange 656 on the downstream end of the plunger body and the spigot 668a enters the interior of the tubular spout 652b. Over most of its length, the inner diameter of the tubular spout 652b is larger than the outer diameter of the spigot 668a so that liquid is able to flow between the spigot and the inner surface of the spout to exit the dosing chamber 672. However, at its downstream end, the inner diameter of the tubular spout 652b is reduced, as indicated at 652d. When the spigot 668a enters this reduced diameter region 652d, the tubular spout 652b seals about the spigot 668a preventing further liquid from being dispensed. This ends the spraying cycle and the bird beak valve 674a closes.

During the spraying cycle, the pressure of the air and liquid is maintained constant as the volume of the pump chamber 624 continues to reduce as the rolling diaphragm 652a is deflected to reduce the volume of the fluid dosing chamber 672. Once spraying has stopped the outlet valve member 634 is able to recover and the bird beak valve 634d of the outlet valve member also closes.

To actuate the device again the user first retracts the plunger assembly 614 to re-charge the dosing and pump chambers 672, 624. As the plunger assembly 614 is retracted, the contact between the inner wall of the rolling diaphragm 625a and the tubular portion 690b is sufficient that the rolling diaphragm is drawn away from the plunger main body forcing the dosing chamber 672 to recover, and increasing the volume of the chamber.

The increasing volume of the dosing chamber 672 results in a drop in pressure inside the chamber compared to atmospheric, drawing a fresh charge of liquid from the fluid source chamber 659 into the dosing chamber. As liquid is drawn out of the fluid source chamber 659, the follower 662 advances to maintain the pressure in the fluid source chamber substantially at atmospheric.

Once the fluid dosing chamber 672 is fully recovered, continued retraction of the plunger assembly 614 draws the rolling diaphragm away from the tubular portion 690b of the cap and the volume of the pump chamber 624 is increased, drawing a fresh charge of air into the pump chamber 624 past the seal member 680. The plunger assembly 614 is retracted until corresponding stops (not shown) on the plunger assembly and dispenser main body 612 are engaged preventing the plunger assembly

614 from being withdrawn fully from the cylinder 622. The dispenser is then ready for a further actuation.

The lengths of the tubular portion 690b of the cap and the tubular spout 652b as well as the initial position of the rolling diaphragm before its is compressed are selected so that the outlet valve is only opened and liquid is only sprayed from the dosing chamber once a desired air pressure has been achieved in the pump chamber 624. This arrangement effective operates as a pre-compression valve arrangement. Typically, the air pressure at which the dispenser operates will be in the range of 0.1 to 0.6 Mpa (1-6 Bar) with 0.3 Mpa (3 Bar) being the average.

In the present embodiment, the beak valve 634b on the outlet valve member 634 opens before liquid is sprayed from the dosing chamber so that only air is dispensed initially. This can help to ensure that the liquid is sprayed effectively as soon as it is released from the dispensing chamber and avoids stuttering. The design can also be modified to ensure that air continues to be dispensed for a brief period after the fluid dosing chamber has closed. This helps to prevent stuttering of the spray towards the end of the spray cycle and helps to clear the outlet passages. However, the design can be modified so that both valves 674a and 634d open simultaneously or it can be arranged so that liquid is sprayed into the tubular portion of the outlet valve member before the outlet valve 634d is opened.

The arrangements described in relation to the latest embodiment 610, including the modified traveller seal and the modified outlet with the tubular outlet valve member, can be applied to any of the previous embodiments, including the dual chamber dispensers. Indeed, it should be noted that the various embodiments are intended to show a range of different features which can be adapted and combined in any suitable way. Thus any of the features shown in respect of any one of the embodiments can be combined with any of the features from any other of the embodiments in any suitable manner in accordance with the invention. For example, the dispenser 610 could be modified so that the main body 612 has an outer casing similar to that shown in the first embodiment and/or an actuating member and/or dual or multiple pump chambers.

It will be appreciated that rather then being in the form of a rolling diaphragm, the traveller seal 652 could be in the form of a bellows or resiliently deformable dome. In addition, the dispenser 610 could be modified to use a pre-compression outlet valve arrangement as described in relation to any of the previous embodiments.

A particular advantage of the dispenser 610 in accordance with the latest embodiment is that the liquid is sprayed to mix with the air within the confines of the tubular portion 634b of the outlet valve member and the tubular portion 690b of the cap. This in effect forms a small pre-outlet mixing chamber within the pump chamber close to the outlet of the pump chamber. This provides for a more even mixing of the air and liquid which is particularly advantageous. The grooves 69Og and 634e may be arranged so that the air entering the mixing chamber is caused to spin, which encourages the liquid and air to mix thoroughly. Furthermore, the outlet passage 693 may be modified to include one or more swirl chambers or other equivalent arrangement. In one embodiment, not shown, a nozzle is mounted to the outlet stem 692 which includes a swirl chamber and at least one final dispenser outlet orifice.

It will be appreciated that there other arrangements could be used to provide a mixing chamber within the pump chamber close to the pump chamber outlet into which the liquid can be introduced and such a concept may be claimed. Furthermore, it would be possible to arrange for a mixing chamber to be provided downstream from the pump chamber outlet, with at least some of the air being directed from the pump chamber into the mixing chamber via a first fluid passage means and the liquid, or other fluid, being directed into the mixing chamber through a second fluid passage means. Such an arrangement is shown Figures 12 to 14, which illustrate an embodiment of a dispenser 710 similar to the previous embodiment 610 but which is adapted to be actuated by means of a lever 783. The dispenser 710 has a main body 712 with an outer casing 716 and a tubular core 718 which defines the pump cylinder 722. The plunger assembly 714 has a plunger body 750 to which is mounted a traveller member and seal 752. The traveller member 752 in this case is in the form of a rolling diaphragm 752a similar to the previously described embodiment. To guide the plunger assembly 714 for movement within the main body 712, the inner end of the plunger body 750 comprises an inner portion 750a which engages in pump cylinder 722 and an outer annular wall 750b which locates between the tubular core 718 and the outer casing 716.

The actuation lever 783 is mounted by means of a hinge pin 783a to a hook like member 716a extending outwardly on the outer casing 716 on one side. The lever has an actuator arm 783b which is received in an aperture 716b in a rear surface of the outer casing 716. A pin (not shown) projects from the actuator arm 783b to engage in a suitable hole or recess in the outer annular wall 750b of the plunger body. The arrangement is such that pivotal movement of the lever 783 about the hinge pin 783a causes the plunger to move axially along the cylinder 722 to actuate the dispenser

710.

An air inlet opening 716c is provided in the outer casing 716 to admit air into the main body between the outer casing 716 and the tubular core 718, from where the air is able to enter the pump chamber 724 past the lip seal 780 when the plunger is retracted, as described in relation to the previous embodiment.

The outlet region of the pump chamber 724 in this embodiment is similar to the previous embodiment but is adapted so that at least a portion of the air from the pump chamber 724 is directed along a separate outlet passage towards a mixing chamber where it mixes with the liquid from the fluid dosing chamber 772 prior to passing through one or more final dispenser outlet orifices. Thus the end cap in this embodiment is provided in two parts, an outer end cap 790 and an inner end cap 790'. The inner end cap 790' is positioned on the open end of the tubular core 718 and is held in position by the outer end cap 790 which engages over the tubular core 718 and is held in position by means of a screw thread or other twist fit arrangement. Seals 790a are provided between to outer end cap 790 and the main body 712 and between the outer end cap 790 and the inner end cap 790' to prevent leakage. The outlet stem 792 of the outer end cap 790 is hollow and receives an insert 794 having a central bore 793 which forms a first fluid outlet passage. Surrounding the insert 794 are one or more air passages 796, through which at least a portion of the air from the pump chamber 724 can be directed separately from the liquid, as will be discussed in more detail below. A nozzle 795 is received in an upper end of the stem 792. The nozzle has at least one final dispenser outlet orifice 738 in fluid connection with a mixing chamber 795a. The bore 793 and the air passages open into a gap between the nozzle 795 and the insert 794 so that the air and the fluid are directed into the mixing chamber 795a. The inner end cap 790' defines the tubular portion 790b in which the tubular spout 752b on the traveller member is received when the dispenser is actuated. In this embodiment, the tubular outlet valve member 734 is mounted to a lower spigot portion 794a of the insert in the outer end cap. The valve member 734 is similar to the valve 634 in the previous embodiment and has an upper resiliently flexible portion which defines the base 734a, the resiliently deformable portion 734c and the tubular portion 734b. However, in this embodiment a rigid plastics tube member 734e is mounted to the flexible tubular portion 734b and projects into the tubular portion 790b of the inner end cap. The flexible portion of the valve member 734 also includes a slit valve 734d which is located about the inner end of the spigot portion 794a of the insert to control the flow of fluid through the bore 793. When the valve member is in its relaxed, normally biased state as shown in Figure 14, the slit valve is closed thus closing the outlet bore 793. The resiliently flexible portion of the valve member 734 in this embodiment also has a further valve member 734f which controls the flow of air through the air passages 796. When the valve member 734 is in its initial relaxed state as shown in Figure 14, the valve member closes off the air passages 796 preventing pressurised air in the pump chamber from enter in the air passages.

The traveller member 752 has a resiliently flexible rolling diaphragm portion 752a and a tubular spout 752b, which projects axially into the pump chamber 724 to be received in the tubular portion 790b of the end cap in the same manner as the previous embodiment. However, in this embodiment, the tubular spout 752b is closed at its upper end by a slit type valve 774a rather than by a bird beak valve. In addition, the tubular spout has a smaller diameter portion 752c at its free end so that a shoulder 752d is defined between the smaller and larger diameter portions for engagement with the rigid tube member 734e on the outlet valve 734. This embodiment also differs from the previous one in that a number of orifices 768b extend through the wall 768 which separates the fluid dosing chamber 772 from the fluid source chamber 759 to provide an inlet by means of which fluid can be drawn into the dosing chamber from the source chamber. A flexible valve member may be provided to allow fluid to flow through the orifices from the fluid source chamber 759 into the fluid dosing chamber 772 when the pressure in the dosing chamber 772 is lower than that in the source chamber 759 but to close the orifices to flow in the reverse direction. The dispenser 710 functions in a very similar manner to the previously described embodiment 610 in operation. Thus, with the plunger assembly 714 fully retracted the pump chamber 724 is filled with air and the dosing chamber 772 is filled with a fluid to be dispensed, which in the present case is a liquid. To actuate the dispenser, a user pulls the lever 783 in towards the body of the dispenser which causes the plunger assembly to move axial along the cylinder 722 towards the fully inserted position. This reduces the volume of the pump chamber 724 and the pressure of the air in the pump chamber is increased. The increasing air pressure acts on the liquid in the dosing chamber 772 through the flexible diaphragm so that the pressure of the liquid is also raised but without significantly reducing the volume of the dosing chamber.

As the plunger assembly 714 approaches the fully inserted position, the tubular spout 752b on the traveller member 625 enters the tubular portion 790b on the inner end cap 790' and the shoulder 752d engages the tube member 734e of the outlet valve 734. Further inward movement of the plunger assembly 714 causes the resiliently deformable portion 734c of the valve member to deflect which in turn causes the valve member 734f to move, thus opening the air passages 796 in the outer end cap. Pressurised air is then able to flow from the pump chamber 724 into the air passages 796, passing between the tubular portion 790b of the inner end cap and the spout 752b and the valve member 734. At the same time, or after a short delay, movement of the valve member 734 also causes the slit valve portion 734d of the valve member to open, so that a flow path is created between the interior of the valve member 734 and the bore 793 in the insert 794. Engagement between the spout 752b and the outlet valve member 734 as the plunger assembly continues to move towards the inserted position also results in the rolling diaphragm portion 752a of the traveller member being deflected thus reducing the volume of the dosing chamber 772, raising the pressure of the liquid inside. As the pressure of the liquid in the dosing chamber 772 increases, the slit valve 774a of the traveller member opens and liquid is ejected into the interior of the valve tube member 734e, from where it flows through the open slit valve portion 734d and into the bore 793. In the present embodiment, some of the pressurised air from the pump chamber 724 is also able to flow into the tube member 734e and mixes with the liquid to flow through the bore 793. The air can be arranged to flow into the valve member about the spout 752b and/or openings 734g can be provided through the rigid tube member 734e

The air flowing through the air passages 796 enters the chamber 795a to mix with the air and liquid mixture flowing through the bore 693 before the final air and liquid mixture passes through the final outlet orifice(s) 738 to be dispensed as a spray.

Spraying continues until the plunger assembly reaches the fully inserted position at which time the pressure in the dosing chamber 772 falls and the traveller member slit valve 774a closes. In some applications, it may .be advantageous to arrange for slit valve 774a to close to prevent further liquid from being dispensed whilst pressurised air is still present in the pump chamber 724, so that the air continues to flow through the outlet passages for a brief period of time after the liquid flow has stopped. This helps to prevent spluttering of the spray during the final stages and helps to clear the outlet passages and the nozzle.

To reset the dispenser, the lever 783 is moved away from the body 712 of the device to move the plunger assembly towards the retracted position. Initial movement of the plunger assembly towards the retracted position causes the rolling diaphragm

752a to recover, increasing the volume of the dosing chamber 772 and drawing in a fresh charge of liquid as described in relation to the previous document. Once the rolling diaphragm has recovered, further movement of the plunger assembly 714 towards the retracted position separates the traveller member 752 from the tubular portion 790b of the end cap so that the volume of the pump chamber 724 is increased and air is drawn into the pump chamber past the seal 780. Once the plunger assembly 714 is fully retracted, the dispenser is ready to be actuated again.

A resilient means, such as a spring, may be provided to bias the plunger assembly 714 towards the retracted position rather than relying on the user to move the lever 783. In this embodiment, the lever 783 can act as a stop to limit movement of the plunger assembly 714 as it is being retracted. A locking arrangement (not shown) can also be provided to hold the lever 783 against the body after actuation. This is advantageous in preventing inadvertent actuation and in making the dispenser easier to carry around, say in a handbag or suitcase. The precise timing of the opening and closing of the various outlet valves

734f, 734d and 774a can be varied as required for different applications. For example, the valve 734d about the bore 793 in the outlet stem can be arranged to open just before the valve 774a on the traveller member so that pressurised air from the pump chamber begins to flow through the bore 793 before the liquid is expelled from the dosing chamber. Alternatively, the two may open simultaneously. In addition, the valve 774a on the traveller member may be arranged to close slightly before the valve 734f so that air continues to flow along the bore 793 for a short period after the liquid flow as stopped.

The relative proportions of the air which are directed into the mixing chamber in the nozzle 795a separately via the air passages 796 and that which is mixed with the liquid in the outlet valve 734 to pass along the bore 793 can be varied as desired.

In the present embodiment, approximately 75% is directed through the air passages into the nozzle mixing chamber 795a with 25% being mixed with the liquid in the pre-outlet chamber formed in the outlet valve 734. The ratio of air which is directed separately into the nozzle and that which is mixed with liquid in the outlet valve is determined primary by the relative sizes of the flow paths.

In some cases it may be desirable for all of the air to be directed separately to the mixing chamber 795a through the air passages 796 whilst the liquid flows separately through the bore 793 into the nozzle. In this case, the liquid dispensing chamber 772 effectively operates as a second pump chamber inside the first air chamber 724 but the arrangement still has the advantage of a simpler construction than prior known dual chamber pumps and is capable of generating increased air pressure when compared with known air/liquid pumps. In addition, the pressure of the air in the main pump chamber acts on the liquid via the rolling diaphragm so that the pressure of the air and the liquid can be maintained the same or at a given ratio. Providing a separate flow of pressurised air to a mixing chamber in the nozzle provides for improved mixing of the air and liquid just prior to the mixture passing through the final out let orifice. This is particularly advantageous for generating good quality atomised sprays. In some applications, such as for dispensing foams, for example, it may be advantageous for all the air to be mixed with the liquid in the pump chamber 724 or in the outlet valve prior to the pump chamber outlet as with the previously described embodiments.

The provision of an actuation lever 783 makes it easier for a user to apply a relatively high actuation force to the plunger assembly 714 enabling the dispenser to generate higher air pressures and to dispense over a longer period of time. In the dispenser 710 as described above, the whole of the plunger assembly

714 is moved axially to actuate the dispenser. In order to reduce the effort required by the user, the plunger assembly can be modified so that only the upper (as shown) inner part of the plunger assembly 750a which locates in the cylinder 722, or the portion to which the traveller member is mounted, is moved. This can be achieved by providing flexible region between the inner part and the remainder of the plunger assembly which contains the fluid supply reservoir 759. The flexible region may be in the form of a bellows, rolling diaphragm or dome shaped, for example.

In the present embodiment of dispenser 710, the nozzle 795 directs the spray vertically in line with the dispenser. However, as illustrated in Figure 15, the nozzle could 795' be in the form of a cap which locates on the step 792 and is arranged to direct the spray at 90 degrees to the axis of the dispenser or at any other desired angle. Figure 15 illustrates the flow paths of the air, the liquid, and air/liquid mixture through the outlet valve to the final dispenser outlet

It will, be readily appreciated that the actuator lever 783 can be configured in many different ways as will be evident to those skilled in the art. Figures 16 to 18 illustrate a further embodiment of a dispenser 810 in which an actuation lever 838 is configured in the form of a trigger which is pulled towards the body to actuate the dispenser.

In the dispenser 810, the plunger body 850 and the fluid source chamber 859 are formed as an integral part of a main body 812. In this arrangement, the plunger remains stationary relative to the main body and the cylinder 822 is defined by a cylinder member 822a which is moved, by the trigger lever 838 to actuate the dispenser.

The dispenser main body 812 can be formed from any suitable material by any suitable method of manufacture but in the present embodiment is formed from a polymeric material by means of injection moulding. The body 812 is elongate and has a first blind bore 812a aligned generally coaxially with a longitudinal axis of the body to define the fluid source chamber 859 in a lower (as shown) region of the body. A follower 862 is located in the fluid source chamber 859 in a manner similar to that in the previously described embodiments. A second blind bore 812b is provided in the body above the fluid source chamber 859. The second blind bore is angled upwardly (as shown) at an angle of approximately 45 degrees to the longitudinal axis of the body and opens on one side. The plunger body 850 projects into the second blind bore from the lower closed end. The plunger body has an outer first tubular region 854 with a diameter slightly smaller than that of the second bore 812b and an inner smaller diameter tubular region 856. A traveller member 852 is mounted to the smaller diameter region 856 of the plunger body to define a fluid dosing chamber 872. In this embodiment, the fluid source chamber 859 is connected with the fluid dosing chamber by means of a fluid passage 859a defined in the body. The traveller member 852 is adapted to form a one way valve which operates to admit fluid from the fluid source chamber 859 into the dosing chamber 872 when the pressure in the dosing chamber falls below that in the source chamber as the traveller member recovers flowing actuation of the device. Thus the traveller member includes a resiliently deformable flap valve 860 which in its initial biased position, as shown, closes an end of the fluid passage 859a. When the pressure in the dosing chamber 872 falls below that in the source chamber 859, the flap valve is deflected inwardly to admit fluid from the passage 859a into a channel 852e in the traveller member 852. From here the fluid is able to enter dosing chamber 872 either by means of a flow path (not shown) defined between the traveller member 852 and the plunger body or by means of one or more fluid passages (not shown) formed in the plunger body to fluidly connect the channel 852e with the dosing chamber 872. A flow path between the traveller member 852 and the plunger body 850 may be defined by means of one or more grooves form on the inner surface of the traveller member or the outer surface of the plunger body or both.

The cylinder member 822a comprises a tubular body 822b closed at its outer end by an end cap 890 which is formed integrally with the tubular body. The tubular body is dimensioned to the close sliding fit in the second blind bore 812b in the body and its inner end is received in the gap between the surface of the bore 812b and the larger diameter tubular portion 854 of the plunger body. A spring 897 is also located in the gap between the surface of the bore 812b and the larger diameter tubular portion 854 of the plunger body. The spring 897 reacts between the closed end of the blind bore 812b and an inner end of the cylinder member to bias the cylinder member outwardly to a fully retracted position as shown in Figure 18. The traveller member 852 includes a seal member 880 which contacts the inner surface of the tubular body of the cylinder member to define a first air chamber 824 of variable. An air inlet passage 812c connects the closed end of the second bore 812b with atmosphere. When the pump chamber 824 is expanded flowing actuation of the dispenser, a fresh charge of air is drawn into the pump chamber past the seal 880 from the blind bore 812b and the air passage 812c.

The end cap 890 of the cylinder member 822 incorporates and outlet stem 892 on to which is mounted a nozzle insert 826 which defines an outlet orifice 838 and a swirl chamber 842.In this embodiment, the traveller member 852 comprises a rolling diaphragm arrangement similar to that as described above in relation to the embodiments shown in Figures 9 to 11 and 12 to 15. The end cap 890 incorporates a tubular member 890b which receives the tubular spout 852b of the traveller member when the dispenser is actuated and houses an outlet valve member 834. The outlet valve arrangements and the outlet from the traveller member are not shown in detail in Figure 18 but can be configured as described in relation to either of the previous two embodiments described above. The actuation lever or trigger handle 883 is hinged to the main body 812 at an upper position 883a and extends over and around the dispenser body on one side and has an elongate opening 883c through which the nozzle 826 projects. The nozzle 826 has a curved flange 826a which contacts the inner surface of the trigger so that forces can be smoothly transferred between the two.

A locking arrangement is provides to hold the trigger 883 against the body in the fully actuated position as shown in Figure 16. This enables the user to lock the dispenser 810 after actuation and so prevent inadvertent actuation and making device more convenient for carrying around. In the present embodiment, the locking arrangement includes a pair of flanges 883d; located one on either side of the handle towards its free end, in each of which is formed opening 883e. The flanges 883d are arranged to engage about a pair of locking projections 812d on the body, with the projections being received in the openings 883e. To actuate the dispenser, a user simply releases the flanges 883d from the projections which enables the spring 897 to bias the cylinder member 822a and the trigger handle 883 outwardly as show in Figures 17 and 18. This in effect moves the plunger assembly 814 to the fully retracted position, drawing a fresh charge of air into the pump chamber 824 and a fresh charge of fluid, in this case a liquid, into the dosing chamber 872. The user can the squeeze the trigger handle towards the body 812 to move the cylinder member inwardly, which effectively moves the plunger assembly towards the inserted position. This causes the dispenser 810 to dispense a mixture of air and liquid as a spray in the same manner as described above in relation to either of the previous two embodiments.

It is an advantage of the dispenser 810 that the liquid supply chamber 859 is located in the main body 812 rather than in the plunger body, as this enables a larger volume supply reservoir to be provided without increasing the overall size of the dispenser. However, in a modification, the upper part of the dispenser 810 including the plunder assembly, the cylinder member 822a and the trigger actuator 883 could be adapted to be mounted on a separate bottle or other container which acts as the fluid supply chamber. In this case, a dip tube may be provided through which the liquid in the bottle or container can be drawn into the fluid passage 859a or otherwise drawn into the liquid dosing chamber 872. When mounted to a bottle or container, an air release valve may be provided in the dispenser to admit air at ambient pressure into the bottle or container as the contents are drawn into the dosing chamber 872.

The traveller member 852 and the outlet arrangements of the dispenser 810 can be configured in any of the ways described above in relation to any of the previous embodiments and could included dual chamber and plunger assembly arrangements. Furthermore, the spring 897 could be omitted or the traveller member 852 could be modified so as to resiliently bias the cylinder member outwardly in place of the spring.

In any of the embodiments described above where the outlet valve 634, 734, 834 is opened by means of contact between the traveller member and the valve, the valve could be adapted so that its is opened in response to the pressure in the pump chamber reaching a threshold value rather then by contact with the traveller member and this becomes a precompression valve.

Figures 19 to 21 illustrate schematically a further embodiment of a dispenser 910 in accordance with the invention.

The dispenser 910 is similar in overall construction to the previously described embodiment 810 in that the plunger body 950 and the fluid source chamber 959 are provide as part of a main body 912 of the dispenser and a cylinder member is 922a is slidably mounted to the plunger assembly. The main difference is that in this embodiment, the fluid source chamber 959 is aligned with and directly connects to the plunger body in a manner which is similar to the plunger assemblies of the earlier embodiments. The dispenser 910 in accordance with this embodiment has a trigger actuator lever 983 mounted to an upper region (as shown) of the main body 912 by means of a hinge pin 983a. As with the previous embodiment, the outlet stem 992 and nozzle 926 projects through an opening in the trigger handle 983 so that movement of the trigger about the hinge 983a moves the cylinder member 922a axially relative to the plunger assembly 914 to actuate the dispenser.

The traveller member 952 and the outlet arrangements of the dispenser 910 are shown only schematically in the drawings and can be configured in accordance with any of the previous embodiments. In the dispenser embodiments 810, 910, the plunger body 850, 950 is provided as part of the main body and the trigger actuator moves a cylinder member 822a, 922a relative to the plunger assembly. This arrangement is advantageous as the mass of the cylinder member is much less that the plunger assembly, especially when the liquid source chamber is provided as part of the plunger body, and so less force is required to actuate the dispenser. This arrangement is also beneficial in reducing the overall number of component parts required.

A further alternative embodiment of a dispenser 1010 in which a cylinder member is moved relative to the plunger assembly is illustrated schematically in Figures 22 and 23. The dispenser 1110 has a main body 1012 which defines a fluid source chamber 1059 and a plunger body 1050. The plunger body in this case is positioned above (as shown) the fluid source chamber but is turned through 90 degrees relative to a longitudinal axis of the main body. A traveller member 1052 is mounted to the plunger body 1050 to define a fluid dosing chamber 1072 fluidly connected with the fluid source chamber by a fluid passage 1059a.

The cylinder member 1022a is formed integrally with. an actuator arm 1083, which is itself formed integrally with the main body 1012 and connected thereto by means of a live hinge 1098. An outlet for the pump chamber 1024 is formed by means of an outlet passage 1093 and a nozzle insert 1026. As illustrated in Figures 22 and 23, the traveller member 1052 may be of the rolling diaphragm type described above in relation to the dispensers 610, 710, 810 or it may be configured in accordance with any of the previously described embodiments. Similarly, the outlet valve and nozzle arrangements may be configured in accordance with any of the previous embodiments and suitably adapted for use with the traveller member. Figure 24 illustrates a dispenser 1110 in accordance with a further embodiment of the invention and which is specifically adapted for use in dispensing a liquid as foam. In this embodiment, the fluid sources is provided by means of a separate bottle 1159 to which the remaining working components of the dispenser are mounted by means of a screw threaded cap 1198 which attaches to a neck of the bottle in a known manner. The working components of the dispenser 1110 are not shown in detail but could be constructed in accordance with any of the previously described embodiments. In a particularly advantageous manner, the dispenser 1110 may be constructed as described above in relation to the dispenser 810, except that the plunger assembly and the cylinder member are mounted generally vertically, with the liquid dosing chamber being fluidly connected with the interior of the bottle by means of a dip tube 1199. hi this arrangement, the cylinder member can be mounted to or formed integrally with an actuator button 1183 which can be pressed downwardly by a user to actuate the dispenser. This arrangement allows the user to apply a higher actuation force than with a lever or trigger and means that the air and liquid can be dispensed at higher pressures which is beneficial when producing foam. The actuator button includes an angled outlet spout or nozzle 1026.

The nozzle design for a foam dispenser, such as the dispenser 1110 described above, will often comprises one or more mesh filters. Figures 25 to 28 illustrate one possible configuration of a nozzle 2000 for a foam dispenser than could be incorporated into any of the embodiments described herein if the dispenser as to be adapted to dispense a foam.

The nozzle 2000 includes a stepped cylindrical mixing chamber 2001 having a first portion 2002 and a larger diameter second portion 2003. A first inlet 2004 directs liquid or a liquid/air mixture axially into the first mixing chamber 2001. A second inlet 2005 directs air form the pump chamber tangentially into the first portion 2002 of the mixing chamber from one side. This arrangement can be used where the dispenser has a pump chamber outlet of the type described above in relation to the dispenser 710 in which at least some air from the pump chamber is directed separately through air passages 796 in the outlet stem. In this case, the first inlet 2004 in the nozzle will be fluidly connected with the bore 793 in the outlet stem to receive the liquid or a liquid/air mix and second inlet 2005 will be fluidly connected with the air passages 792. Alternatively, the air inlet 2005 may be omitted and the liquid and air mixed in the pump chamber and/or in the outlet valve in the dispenser and directed into the nozzle through the first inlet 2004 only.

A pair of angled fluid passages 2006, 2007 connect the downstream end of the second, larger diameter portion 2003 of the mixing chamber with a swirl chamber 2008. An outlet orifice 2009 is provided in the downstream end of the swirl chamber 2008 through which the air/liquid mixture is sprayed into a larger diameter outlet passage 2010. The angled passages 2006, 2007 direct the liquid/air mix into the swirl chamber so that it contacts the downstream end wall and is caused to spin about the axis of the chamber before passing through the orifice 2009.

Two filter meshes 2011, 2012 are located in the outlet passage 2010 to refine the foam in a manner well known in the art.

Manual dispenser pumps and trigger sprayers spray for a period of 0.2 - 0.6 seconds because it is much more difficult to generate an atomised spray over a long period of time and the droplets tend to be much larger and less consistent, dribbling and jetting are likely during the spray and the actuation force is usually higher. But it is desirable in some applications like body spray, antiperspirant, paint, air freshener, cleaners, oil and the like to spray over a longer period of time for say 1-6 seconds. A longer spray period can be achieved by using a higher ratio of air to liquid as is provided by pump dispensers in accordance with the present invention and by having very small orifices or channels through which the liquid and air must flow. However, this combination requires a high actuation force and so is best achieved using dispensers having an actuator such as a trigger which provides mechanical advantage. Where the liquid and air are mixed in the pump chamber from the dosing chamber, it is necessary to ensure that the liquid is released from the traveller seal into the pump chamber slowly so that it mixes evenly with the air during an extended period of the spray cycle as the plunger is inserted. This is possible by using a very small diameter outlet orifice from the traveller seal configured so that the liquid is sprayed into the pump chamber throughout the length of the stroke or thereabouts. Sometimes with sprays of a long duration of 2 to 6 seconds or more and or a flow of over 0.5 mis per second it isn't practical or desirable to use a high ratio of air either because of the high actuation force required or because the required droplets are large so the air isn't needed to produce finer droplets and because the device would need to be very large to accommodate the air. In these cases the air can be applied at the start of the spray cycle for between 0.05 - 0.5 seconds or the end of it or at the start and end for between 0.05 - 0.5 seconds to prevent very large droplets or even jetting and then either no air or much less air during the rest of the spray cycle. This enables you to use a lot of air when it is most needed but without the penalty of a high actuation force and since much less air is needed for the entire spray cycle, the device can be smaller. In these cases, you would normally use a precompression outlet valve to maintain the required pressure and this would be close to the swirl arrangement and final orifice. This idea can be applied to any type of spray pump or trigger spray pump that combines air and liquor and produces an atomised spray and any of the examples already described.

We have also been able or produce acceptable continuous atomised sprays of 1 - 6 seconds duration with no air at all by using the devices with one or two liquids in both chambers and by using a precompression valve just upstream of a swirl arrangement which is next to the final spray orifice. It is also essential that the distance and open space between the outlet from the pump chamber to the precompression valve is minimised. Normally, you would also use an actuator such as a trigger as the actuation force is higher than usual. The sprays are inferior to those produced with an air liquid pump but they can often be acceptable and the capacity of the pump chamber is usually much larger for an extended spray tune. The idea of generating a continuous atomised spray can be extended to any type of manually operated dispenser or trigger with a precompression valve, a low volume of open space between it and the dispenser outlet and the precompression valve close or next to the swirl arrangement.

Dispensers in accordance with the invention can be adapted to dispense one or more liquids as jet, foam, mousse or as a bolus of liquid by suitable modification of the outlet arrangements in a manner well known in the art.

Sometimes it will be better to have the air in the fluid dosing chamber and the liquid in the other chamber 3002 as in fig 29 and this is advantageous when a low ratio of air to liquid is used or a large volume of liquid is needed or a combination of both. The air would be allowed to enter the pump dosing chamber through a hole in the side wall 3006 through a one way valve 3005. It would come from the outside between the piston and the main body and would exit through the one way outlet valve on the traveller. The seal between the traveller and the cylinder would be a standard seal arrangement with no return valve. The liquid would be stored as before but would exit through a channel 3004 and a one way valve 3003 in the traveller near to the side of the piston into the main pump chamber 3002. Then the device works as before but with the air and liquid reversed with the air pressurised by deforming the traveller and the liquid being pressurised with the movement of the piston and traveller. . Sometimes some air would be allowed to return into the chamber 3002 through the final orifice and past the outlet valve 3000 where it would mix with the liquid drawn in by the return stroke of the piston, and other times no air would be allowed back into the chamber. It would depend on whether or not it is desirable to have additional air available especially at the start and end of the cycle. This also shows a precompression outlet valve 3000 which would be followed by a swirl arrangement and outlet spray orifice which aren't shown. This arrangement can be used in any of the embodiments.

In any of the embodiments described, an interlock mechanism can be provided between the plunger assembly and the main body to prevent inadvertent actuation of the dispenser. For example, in the first embodiment, the ring 82 at the end of the plunger body 50 can be arranged to contact an abutment on the main body 12 when the plunger is twisted through 90 degrees whilst in the inserted position to prevent the plunger being retracted. To actuate the dispenser, the user would first twist the plunger to unlock the mechanism before retracting the plunger in the usual way.

In the embodiments disclosed, the pump cylinders and plungers are normally circular in lateral cross section as this is the easiest shape to seal but this is not essential and they could be any suitable shape, such as oval for example.

In an alternative embodiment, not shown, two or more pump cylinders can be joined together in a single main body with each having separate outlets and plunger assemblies. The plunger assemblies could each contain different volumes of liquor and even use different volumes of air (by varying the diameter of the pump cylinders) and each cylinder and plunger assembly would in effect act as a separate dispenser. During manufacture, the plunger bodies could all be moulded together and be loosely connected to each other so that they can be snapped apart before being used. With this arrangement, a number of products can be provided in a combined dispenser that would take up considerably less room than an equivalent number of separate dispensers. This may be advantageous for people travelling on an aeroplane for example. The products could be any suitable combination and could include pharmaceuticals and/or personal care products for example.

This concept can be taken further with different products being available in refill tubes that can be pushed into the plunger assembly with each tube having its own follower. Alternatively, the refill tubes could be flexible tubes or sachets so they would collapse as they emptied. In a further alternative, a product could be provided in a separate plunger assembly that replaces one of the plunger assemblies in one of the pump cylinders. The refills may be coded in some way, for example colour coded, so that certain refills will only be used with particular pump cylinders. With this system a range of different products can be provided in re-fills for use with one dispenser.

Rather than each pump cylinder having a separate outlet, two or more of them may have outlet passages that join to produce a common delivery. This could be used to enable users to combine products in various ways. For example, users could make up their own perfumes by mixing the appropriate refills. The volumes delivered by each pump cylinder/plunger assembly may be varied to control the mix of products. Thus one cylinder/plunger assembly may deliver a main product, such as water or alcohol, and the other pump cylinder/plunger assemblies can be arranged to deliver a smaller volume such as for scents. With all of these designs, the air ratio in each pump chamber could be set by varying the diameter of the cylinder. Where two or more products are mixed, it may be preferable to provided one pump chamber with a high ratio of air so that the others can be reduced in size and the overall actuation force minimised.

In the embodiments described above, the liquid or liquids to be dispensed are pressurised together with the air, either by introducing the liquid into the pump chamber itself or by having a collapsible fluid dosing chamber which is subject to the pressure in the pump chamber. In an alternative arrangement, a fluid source chamber could be connected with an outlet passage from the pump chamber to the dispenser outlet by means of a venturi so that liquid is drawn into the air stream as it exits the pump chamber. For example, in the dispenser 210 described above with reference to

Figure 4, the second fluid source chamber 259' could be connected with and outlet passage from the pump chamber 224 by means of a venturi so that the second liquid is drawn into the fluid stream as it passes through the outlet passage rather than being drawn into the pump chamber.

This arrangement could also be used in dispensers not having a traveller seal arrangement. Thus, for example, the dispenser 210 could be modified so that there was no fluid source chamber 259 in the plunger and no traveller seal 252 but a static seal on the plunger body 250. The outer fluid source chamber 259' would then be the only fluid source chamber and this would be connected with an outlet passage from the pump chamber 224 to the outlet nozzle 238 by means of a venturi so that the liquid from the chamber 259' is drawn into the air stream as it flows along the outlet passage. The relative sizes of the outlet passage and the venturi determine to ratio of liquid to air dispensed. This arrangement would also enable a fluid to be dispensed with compressed air in a manual pump dispenser having only one pump chamber and may be claimed separately.

Whilst all the embodiments disclosed herein have been configured to dispense one or more liquid products, dispensers in accordance with the invention can be arranged to dispense powdered products. In essence, the dispenser would be similar those disclosed in the preferred embodiments with the powder being placed in the fluid source chamber and handled in a similar manner to the liquid. The orifices and flow passageways through which the powder passes may have to be enlarged as would the swirl chamber.

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

1. A manually actuated pump dispenser for dispensing a mixture of air and at least one other fluid, the dispenser comprising an final outlet, a cylinder, a plunger assembly slidably received in the cylinder to define within the cylinder a main pump chamber of variable volume, an outlet arrangement fluidly connecting the main pump chamber with the dispenser final outlet including an outlet valve arrangement, an inlet for admitting fluid into the main pump chamber including an inlet valve arrangement, wherein the plunger assembly comprises a plunger body and a traveller member mounted to the plunger body within the cylinder, at least part of the traveller member being movable relative to the plunger body to define with the plunger body a fluid dosing chamber of variable volume, a fluid dosing chamber inlet through which a fluid can be drawn into the fluid dosing chamber and a fluid dosing chamber outlet through which the fluid can be ejected from the fluid dosing chamber to be dispensed together with pressurised fluid from the main pump chamber.

2. A manually actuated pump dispenser as claimed in claim 1, in which the dispenser is configured such that in use during each actuation, at least some of the fluid dispensed from the main pump chamber is mixed with the another fluid dispensed from the fluid dosing chamber upstream of the outlet valve arrangement.

3. A manually actuated pump dispenser as claimed in claim 2, in which the dispenser is configured such that in use during each actuation, all of the fluid dispensed from the main pump chamber is mixed with the another fluid dispensed from the fluid dosing chamber upstream of the outlet valve arrangement.

4. A manually actuated pump dispenser as claimed in claim 2, in which the dispenser is configured such that in use during each actuation, a proportion of the fluid dispensed from the main pump chamber is mixed with the another fluid dispensed from the liquid dosing chamber downstream of the outlet valve arrangement.

5. A manually actuated pump dispenser as claimed in claim 4, in which the dispenser is configured such that approximately 75% of the fluid dispensed from the main pump chamber is mixed with the another fluid downstream of the outlet valve arrangement.

6. A manually actuated pump dispenser as claimed in claim 1, in which the dispenser is configured such that in use during each actuation, fluid dispensed from the main pump chamber is mixed with the another fluid dispensed from the liquid dosing chamber downstream of the outlet valve arrangement.

7. A manually actuated pump dispenser as claimed in any one of claims 1 to 3, in which the outlet arrangement comprises a common flow path from the main pump chamber to the final outlet and a common outlet valve for controlling the flow of fluid through the common flow path.

8. A manually actuated pump dispenser as claimed in any one of claims 1, 2, 4, 5 or 6, in which the outlet arrangement comprises a first flow path to the dispenser final outlet through which said another fluid flows and a second flow path fluidly connecting the main pump chamber with the dispenser final outlet through which only fluid from the main pump chamber flows, the first flow path comprising a first outlet valve for controlling the flow of liquid through the through the first flow path, the second flow path comprising a further outlet valve for controlling the flow of fluid through said second flow path.

9. A manually actuated pump dispenser as claimed in claim 6, in which the first and second flow paths combine downstream of the first and second outlet valves prior to the final dispenser outlet.

10. A manually actuated pump dispenser as claimed in claim 9, in which the first and second flow paths combine in a mixing chamber upstream of the final outlet.

11. A manually actuated pump dispenser as claimed in any one of claims 1, 2, 3, or 7, in which the fluid dosing chamber outlet directs said another fluid into the main pump chamber, so that in use, the liquid mixes with the fluid in the main pump chamber before passing through a common outlet from the main pump chamber to the dispenser final outlet.

12. A manually actuated pump dispenser as clamed in any one of claims 1, 2, 4, 5, 6, 7 or 8, in which the dispenser further comprises a first outlet port fluidly connected with the final dispenser outlet by a fluid passage, a means for defining an pre-outlet chamber upstream of the first outlet port, at least during actuation of the dispenser, said fluid dosing chamber outlet being configured to direct said another fluid into the pre-outlet chamber.

13. A manually actuated pump dispenser as claimed in claim 12, in which the dispenser comprises an inlet to the pre-outlet chamber through which air from the main pump chamber can access the pre-outlet chamber to mix with the another fluid.

14. A manually actuated pump dispenser as claimed in claim 12 or claim 13, in which the dispenser comprises a further outlet port in fluid connection with the dispenser final outlet by a fluid passage means, the further outlet port being in fluid connection with the main pump chamber.

15. A manually actuated pump dispenser as claimed in claim 14 when dependant on any one of claims 8, 9 or 10, in which the first outlet port comprises part of the first flow path and the further outlet port comprises part of the second flow path.

16. A manually actuated pump dispenser as claimed in any one of the previous claims, in which the plunger assembly and cylinder are movable relative to one another between an inserted position in which the volume of the main pump chamber is at a minimum and a retracted position in which the volume of the main pump chamber is at a maximum.

17. A manually actuated pump dispenser as claimed in any one of the previous claims, in which the traveller member is movable relative to the plunger body between an extended configuration in which the volume of the fluid dosing chamber is at a maximum and a contracted configuration in which the volume of the fluid dosing chamber is at a minimum.

18. A manually actuated pump dispenser as claimed in claim 17, in which the traveller member is slidably mounted to the plunger body for movement between the extend and contracted configurations.

19. A manually actuated pump dispenser as claimed in claim 17, in which the traveller member is resiliently deformable between the extended and contracted configurations.

20. A manually actuated pump dispenser as claimed in any one of claims 17 to 19 when dependent on claim 16, in which the dispenser is configured such that in use, the traveller member is moved from the contracted configuration to the extended configuration as the plunger assembly and cylinder are moved from the inserted position towards the retracted position, the arrangement being such that in use, a volume of said another fluid is drawn into the fluid dosing chamber from the fluid reservoir as the volume of the fluid dosing chamber increases.

21. A manually actuated pump dispenser as claimed in claim 20, the dispenser being configured such that in use, the traveller member is moved from the extended configuration to the contracted configuration as the plunger assembly and cylinder are moved from the retracted position to the inserted position, the arrangement being such that in use, a volume of said another fluid in the fluid dosing chamber is ejected through the fluid dosing chamber outlet as the volume of the fluid dosing chamber is reduced.

22. A manually actuated pump dispenser as clamed in claim 21, in which the traveller member engages with at least one wall of the pump chamber, the arrangement being such that during at least an initial range of movement between the plunger assembly and the chamber from the retracted position towards the inserted position, the resistance between the traveller member and a chamber wall is sufficient to cause the traveller member to move from the extended configuration to the contracted configuration.

23. A manually actuated pump dispenser as claimed in claim 21, in which the dispenser comprises an abutment arranged to contact the traveller member to move the traveller member from the extended position towards the contracted position as the plunger assembly and cylinder are moved from the retracted position towards the inserted position.

24. A manually actuated pump dispenser as claimed in any one of claims 16 to 23 when dependent on claim 12, in which the traveller member has a formation which co-operates with a corresponding formation associated with a body of the dispenser to define the pre-outlet chamber when the plunger assembly and cylinder are at or close to the inserted position.

25. A manually actuated pump dispenser as claimed in claim 24, in which the outlet valve arrangement comprises a resilient valve member having a first valve portion configured to close the first outlet port when the valve member is in an initial resiliently biased configuration, the traveller member having an abutment arranged to contact the valve member and deform it from its initial resiliently biased configuration to open the first outlet port as the plunger assembly and cylinder approach the inserted position.

26. A manually actuated pump dispenser as claimed in claim 25, in which the valve member has a tubular portion, the traveller member having a spout configured to engage in the tubular portion to define the pre-outlet chamber as the plunger assembly and cylinder approach the inserted position, the fluid dosing chamber outlet being positioned in the spout, such that in use, fluid is ejected from the fluid dosing chamber into the interior of the tubular portion.

27. A manually actuated pump dispenser as claimed in claim 26 when dependant on claim 13, in which the inlet comprises one or more groves in at least one of the tubular portion and the spout.

28. A manually actuated pump dispenser as claimed in any one of claims 25 to 27 when dependent on claim 14, in which the valve member has a second valve portion configured to close the further outlet port when the valve member is in its initial resiliently biased configuration, the valve member being configured such that the second valve portion is deflected to open the further outlet port when the vale member is deformed.

29. A manually actuated pump dispenser as claimed in any one of the previous claims, in which the traveller member comprises an integral seal member which engages the wall of the cylinder to act as a seal between plunger body and the cylinder wall.

30. A manually actuated pump dispenser as claimed in any one of claims 1 to 28, in which a seal member is mounted to one of the plunger body and the traveller member for engagement with the wall of the pump cylinder to act as a seal between plunger assembly and the cylinder wall.

31. A manually actuated pump dispenser as claimed in claim 17, or any one of claims 18 to 30 when dependent on claim 17, in which the traveller member is configured to seal the inlet to the fluid dosing chamber when in the contracted configuration.

32. A manually actuated pump dispenser as claimed in any one of claims 1 to 30, in which the inlet to the fluid dosing chamber comprises a one-way valve configured to open to admit the another fluid into the dosing chamber only when the pressure in the fluid dosing chamber is lower than the ambient pressure by a threshold amount.

33. A manually actuated pump dispenser as claimed in claim 16, or any one of claims 17 to 31 when dependent on claim 16, in which the dispenser comprises apparatus arranged to seal the outlet of the fluid dosing chamber when the plunger is at the inserted position.

34. A manually actuated pump dispenser as claimed in claim 33, in which the dispenser comprises a projection configured to engage in a recess defined by the traveller member to seal the outlet of the fluid dosing chamber when the plunger assembly and cylinder are at the inserted position.

35. A manually actuated pump dispenser as claimed in any one of claims 1 to 32, in which the outlet of the fluid dosing chamber comprises a one way valve configured to open to enable fluid to exit the fluid dosing chamber when the fluid pressure inside the dosing chamber is higher than a predetermined a threshold amount.

36. A manually actuated pump dispenser as claimed in claim 35 when dependent on claim 22, in which the one way valve is configured to open when the pressure inside the fluid dosing chamber is higher than the pressure in the main pump chamber by a threshold amount.

37. A manually actuated pump dispenser as claimed in claim 35 when dependent on claim 26 and claim 23, in which, in use as the plunger assembly and cylinder approach the inserted position, contact between the spout and the tubular portion causes the traveller member move to the contracted position pressurising the fluid in the fluid dosing chamber, the one way valve being configured to open to release fluid from the liquid dosing chamber into the pre-outlet chamber when the pressure of the fluid in the dosing chamber is at or above the threshold amount.

38. A manually actuated pump dispenser as claimed in any one of the previous claims, in which the fluid source comprises a fluid source chamber for holding a volume of said another fluid.

39. A manually actuated pump dispenser as clamed in claim 38, in which the fluid source chamber is provided in or mounted to the plunger body.

40. A manually actuated pump dispenser as claimed in claim 39, in which the plunger body is configured to receive an insert which defines the fluid source chamber.

41. A manually actuated pump dispenser as claimed in claim 38, in which the plunger body and the fluid source chamber are formed integrally as part of a main body of the dispenser, the cylinder being slidably mounted to the plunger assembly from movement relative thereto.

42. A manually actuated pump dispenser as claimed in any one of claims 38 to 41, in which an upstream end of the fluid source chamber is sealed by means of a follower, the follower being movable relative to the fluid source chamber in a downstream direction under the influence of ambient air pressure as fluid is drawn out of the fluid source chamber, so as to maintain the pressure of the fluid in the chamber substantially at ambient in use.

43. A manually actuated pump dispenser as claimed in any one of claims 38 to 41, in which at least one wall of the fluid source chamber is deformable, the arrangement being such that in use, the volume of the fluid source chamber is reduced under the influence of ambient air pressure as fluid is drawn out of the fluid source chamber to maintain the pressure of the fluid in the chamber substantially at ambient.

44. A manually actuated pump dispenser as claimed in any one of claim 38 to 41, in which the fluid dosing chamber inlet comprises a dip tube through which fluid is drawn out of the fluid source chamber in use, the dispenser further comprising an air leak arrangement for admitting ambient air into the fluid source chamber as fluid is drawn out of the chamber in use, the fluid source chamber being a plastic container or bottle.

45. A manually actuated pump dispenser as claimed in any one of the preceding claims, in which the dispenser is configured to dispense a mixture of air and at least two other fluids.

46. A manually actuated pump dispenser as claimed in claim 45, in which the ' dispenser comprises two or more main pump chambers, the dispenser being configured such that each main pump chamber delivers a mixture of air and at least one other fluid under pressure to the dispenser final outlet.

47. A manually actuated pump dispenser as claimed in claim 46, in which the dispenser comprises a separate dispenser final outlet for each main pump chamber.

48. A manually actuated pump dispenser as claimed in claim 46, in which at least two main pump chambers are fluidly connected with a common dispenser final outlet.

49. A manually actuated pump dispenser as claimed in any one of the preceding claims, in which the dispenser is configured to dispense a mixture of air and at least one other fluid and the air is in the dosing pump chamber.

50. A manually actuated pump dispenser as claimed in claim 22 or any one of claims 23 to 49 when dependent on claim 22, in which the dispenser further comprises an actuator mechanism operable to move the plunger assembly and cylinder between the inserted and retracted positions to actuate the dispenser.

51. A manually actuated pump dispenser as claimed in claim 50, in which the actuator mechanism is operative on the plunger assembly to move the plunger assembly relative to the cylinder from the retracted position to the inserted position.

52. A manually actuated pump dispenser as claimed in claim 50, in which the actuator mechanism is operative on the cylinder to move the cylinder relative to the plunger assembly from the retracted position to the inserted position.

53. A manually actuated pump dispenser as claimed in any one of claims 50 to 52, in which the actuator mechanism comprises an actuator lever to which a user may apply a force to move the plunger assembly and cylinder from the retracted position to the inserted position.

54. A manually actuated pump dispenser as claimed in claim 53, in which the actuator leaver is in the form of a trigger.

55. A manually actuated pump dispenser for dispensing a mixture of air and at least one other fluid, in which the dispenser comprises a pump chamber for pressurising air, an outlet, an outlet passage fluidly connecting the pump chamber and the outlet and a fluid source chamber for holding a volume of fluid to be dispensed, the fluid source chamber being fluidly connected with the outlet passage by means of a venturi.

56. A manually actuated pump dispenser for dispensing a mixture of air and at least one other fluid, in which the dispenser comprises a pump chamber for pressurising air, an outlet, an outlet passage fluidly connecting the pump chamber and the outlet, the dispenser comprising a chamber in the flow path between the pump chamber and the outlet for receiving an insert containing a fluid product to be dispensed.

57. A manually actuated pump dispenser as claimed in any one of the previous claims in which the other fluid is a mixture of air and a liquid.

58. A manually actuated pump dispenser as claimed in any one of the previous claims in which the other fluid is a liquid.

59. A manually actuated pump dispenser for dispensing a mixture of air and at least one other fluid, in which the dispenser comprises a pump chamber for pressurising at least the air, an outlet, an outlet passage fluidly connecting the pump chamber and the outlet and a fluid source chamber for holding a volume of fluid to be dispensed, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 1 second.

60. A manually actuated pump dispenser as claimed in claim 59, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 2 seconds.

61. A manually actuated pump dispenser as claimed in claim 59, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 3 seconds.

62. A manually actuated pump dispenser as claimed in claim 59, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 1 , 2, 3, 4 or 5 seconds.

63. A manually actuated pump dispenser in any of the claims 59 to 62 that has a precompression valve close to and upstream of a swirl chamber or equivalent, which is next to the final spray orifice.

64. A manually actuated pump dispenser as claimed in any one of the previous claims where air is one of the fluids, in which the air is added to the liquid at the start of the spray only for between 0.05 - 0.3 seconds.

65. A manually actuated pump dispenser as claimed in any one of the previous claims where air is one of the fluids, in which the air is added to the liquid at the end of the spray only for between 0.05 - 0.3 seconds

66. A manually actuated pump dispenser as claimed in any one of the previous claims where air is one of the fluids, in which the air is only added to the liquid at the start of the spray for between 0.05 — 0.3 seconds and at the end of the spray for between 0.05 - 0.3 seconds.

67. A manually actuated pump dispenser as claimed in any one of the previous claims where air is one of the fluids, in which the rate of air added to the liquid is much lower during most of the spray cycle than at the start or end of the spray.

68. A manually actuated pump dispenser as claimed in any one of the claims 59 to 67, in which the actuator mechanism comprises an actuator lever to which a user may apply a force to actuate the dispenser.

69. A manually actuated pump dispenser as claimed in claim 68, in which the actuator mechanism comprises an actuator lever to which a user may apply a force to actuate the dispenser and that actuator lever is a trigger.

70. A manually actuated pump dispenser as claimed in any one of the claims 59 - 69, in which the dispenser comprises a plunger in a cylinder and the actuator mechanism comprises an actuator lever to which a user may apply a force to move the plunger assembly and cylinder from the retracted position to the inserted position and that actuator lever is a trigger.

71. A manually actuated pump dispenser for dispensing at least one fluid, in which the dispenser comprises a pump chamber for pressurising the liquid , an outlet, an outlet passage fluidly connecting the pump chamber and the outlet and a fluid source chamber for holding a volume of fluid to be dispensed, a precompression valve close to and upstream of a swirl chamber or swirl device, which is next to the final spray orifice, in which the actuator mechanism comprises an actuator lever to which a user may apply a force to actuate the dispenser and that actuator lever is a trigger and the dispenser is configured to produce a continuous atomised spray having a duration of at least 1 second.

72. A manually actuated pump dispenser as claimed in claim 71, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 2 seconds.

73. A manually actuated pump dispenser as claimed in claim 71, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 3 seconds.

74. A manually actuated pump dispenser as claimed in claim 71, in which the dispenser is configured to produce a continuous atomised spray having a duration of at least 1, 2, 3, 4 or 5 seconds.

75. A manually actuated pump dispenser as claimed in any one of the previous claims where air is one of the fluids, in which the dispenser is configured to produce foam.

76. A manually actuated pump dispenser as claimed in any one of the previous claims where the pump chamber holds at least 2 mis of liquid and in which the actuator mechanism comprises an actuator lever to which a user may apply, a force to actuate the dispenser and that actuator lever is a trigger and the dispenser is configured to produce a continuous atomised spray having a duration of at least 1 second.

77. A manually actuated pump dispenser as claimed in any one of the previous claims where the pump chamber holds at least 2 mis of liquid and in which the actuator mechanism comprises an actuator lever to which a user may apply a force to actuate the dispenser and that actuator lever is a trigger and the dispenser is configured to produce a continuous atomised spray having a duration of at least 2 seconds.