Spray Head With Radially Separable Segments

Abstract

A spray head for atomising fluid ejected from a fluid conduit, the spray head comprising: a body having a longitudinal bore for receiving the fluid conduit such that a distal tip of the fluid conduit extends to a distal end of the longitudinal bore, the body being configured to direct a balanced flow of gaseous medium over the distal tip of the fluid conduit, when received within the longitudinal bore, so as to promote atomisation of the fluid as it is ejected from the distal tip of the fluid conduit, wherein the body comprises at least two radially separable segments, each of which defines part of the longitudinal bore, said at least two segments when combined forming said body having a longitudinal bore, whereby the fluid conduit is received within the longitudinal bore by locating said at least two segments around the fluid conduit.

Claims

1. A spray head for atomizing fluid ejected from a fluid conduit, the spray head comprising: a body having a longitudinal bore for receiving the fluid conduit such that a distal tip of the fluid conduit extends to a distal end of the longitudinal bore, and one or more outlets configured to direct a balanced flow of gaseous medium over the distal tip of the fluid conduit, when received within the longitudinal bore, so as to promote atomization of the fluid as it is ejected from the distal tip of the fluid conduit, wherein the body comprises at least two radially separable segments, each of which defines part of the longitudinal bore, said at least two segments when combined forming said body having a longitudinal bore, whereby the fluid conduit is received within the longitudinal bore by locating said at least two segments around the fluid conduit.

2. The spray head of claim 1, wherein said at least two segments are configured to locate around the fluid conduit from the sides of the fluid conduit, from a generally radial or generally oblique direction.

3. The spray head of claim 1, wherein said at least two segments are configured to: locate around the fluid conduit such that at least a portion of the fluid conduit is retained within the longitudinal bore; and secure, within the longitudinal bore, a portion of the fluid conduit that is remote from the distal tip of the fluid conduit, thereby leaving the distal tip unsecured.

4. (canceled)

5. The spray head of claim 1, wherein the at least two segments are arranged to form a substantially fluid-tight seal between the bore and at least a portion of the fluid conduit whereby to inhibit flow of the gaseous medium along the outside of the fluid conduit.

6. The spray head of claim 1, wherein said at least two segments are separable along a split line that is coaxial with the longitudinal bore.

7. The spray head of claim 1, wherein the longitudinal bore is located generally at the center of the body when the at least two segments are combined to form the body.

8. The spray head of claim 1, wherein each of said at least two segments comprises a radial projection, located on an inner surface of said part of the longitudinal bore, for engaging a distal portion of the fluid conduit within the bore.

9. The spray head of claim 8, wherein the radial projection extends in a longitudinal direction along the inner surface of said part of the longitudinal bore.

10. The spray head of claim 1, wherein: the body is further configured to define an annular gap at the distal end of the longitudinal bore, between the body and the distal tip of a fluid conduit received therein, through which the gaseous medium can be flowed thereby to direct said balanced flow of gaseous medium over the distal tip of the fluid conduit; and said annular gap is provided by a formation at the distal end of said part of the longitudinal bore on one of said at least two segments, and the other of said at least two segments is configured to receive the formation when the at least two segments are combined thereby to define the annular gap.

11. (canceled)

12. The spray head of claim 1, wherein the at least two segments each define part of an annular chamber within the body that is completely formed when the at least two segments are combined to form the body, said chamber being in fluid communication with the distal end of the longitudinal bore.

13. The spray head of claim 12, wherein: the chamber is further arranged to receive a flow of gaseous medium from an external source at a pressure of less than 0.1 MPa; and the gaseous medium is compressed air.

14. The spray head of claim 12, further comprising at least one port provided on a distal face of each of said at least two segments for ejecting a stream of gaseous medium from the body, wherein said at least one port comprises at least two ports, each having a different configuration and each in fluid communication with the chamber.

15. (canceled)

16. The spray head of claim 1, wherein each of said at least two segments further comprises a horn portion extending from an edge of each segment in a longitudinal directions, said horn portion having at least one horn port configured to direct a flow of gaseous medium across a distal face of the body whereby to flow form the atomized fluid into a desired shape.

17. The spray head of claim 16, wherein the horn port is configured to direct the flow of gaseous medium at an angle of less than 90 degrees relative to an axis of a cannula.

18. The spray head of claim 16, wherein said flow of gaseous medium is supplied by an external source in direct fluid communication with each of said horn portion.

19. The spray head of claim 1, wherein the longitudinal bore is adapted to receive a fluid conduit configured as a needle, the needle is configured as a cannula comprising a hollow shaft with substantially parallel walls.

20. The spray head of claim 1, wherein the longitudinal bore is adapted to receive a fluid conduit configured as a nozzle having a conical or tapered configuration.

21. A kit of parts, comprising: at least one fluid conduit for providing a flow of fluid; and a spray head having a body comprising: at least two radially separable segments that, when combined, form a longitudinal bore for receiving the fluid conduit therewithin such that a distal tip of the fluid conduit extends to a distal end of the longitudinal bore; and one or more outlets configured to direct a balanced flow of gaseous medium over the distal tip of the fluid conduit, when received within the longitudinal bore, so as to promote atomization of the fluid as it is ejected from the distal tip of the fluid conduit.

22. A kit of parts according to claim 21, wherein said at least one fluid conduit has a fluid reservoir connected thereto, such that the fluid conduit and fluid reservoir form a cartridge.

23. A method of using a spray head, the method comprising: providing a fluid conduit for delivering a flow of fluid; providing a spray head comprising a body formed of at least two radially separable segments; and locating said at least two segments of the body around the fluid conduit to form the body of the spray head.

24-27. (canceled)

Description

FIGURES

[0050] An exemplary embodiment of the present invention will now be described with reference to the following figures, in which:

[0051] FIGS. 1A and 1B show a proximal end view and a side view of a spray head according to a first aspect;

[0052] FIG. 2 shows a front view of the segments that form the spray head of FIG. 1 being located around a fluid conduit in the form of a cannula according to the first aspect;

[0053] FIG. 3 shows a perspective view of the segments that form the spray head in FIG. 2 according to the first aspect;

[0054] FIG. 4 shows a front end face of the spray head according to the first aspect;

[0055] FIGS. 5A and 5B show sectional side views of the spray head of FIG. 4, axially rotated through 90 degrees, respectively, according to the first aspect;

[0056] FIG. 6 shows various illustrative views of the spray head and fluid conduit according to the first aspect;

[0057] FIG. 7 shows side and front end views of the spray head mounted to an actuator and a “syringe” cartridge having a fluid conduit in the form of a cannula according to the first aspect;

[0058] FIGS. 8A to 8C show perspective views of three different types of cannulas that can be used as fluid conduits with the spray head according to the first aspect;

[0059] FIG. 9 shows a front view of the segments that form a spray head being located around a fluid conduit in the form of a conical nozzle according to a second aspect;

[0060] FIG. 10 shows a perspective view of the segments that form a spray head according to the second aspect;

[0061] FIG. 11 shows side and front end views of a spray head according to a second aspect, having a fluid conduit in the form of a conical nozzle, mounted to an actuator and a “syringe” cartridge;

[0062] FIG. 12 shows external and sectional side views of a fluid conduit in the form of a conical nozzle according to a first example; and

[0063] FIG. 13 shows external and sectional side views of a fluid conduit in the form of a conical nozzle according to a second example.

DETAILED DESCRIPTION

[0064] In the following description and accompanying drawings, corresponding features of different embodiments are, preferably, identified using corresponding reference numerals.

[0065] FIGS. 1A and 1B shows an embodiment of the spray head 10 according to a first aspect. A view of the rear end face 102 is shown in FIG. 1A with a side view being shown in FIG. 1B where both the rear end face 102 and a front face 104 can be seen.

[0066] The spray head 10 comprises a generally cylindrical body 100 having a side wall 106 extending between the rear face 102 and front face 104. A centrally located bore 108 extends through the spray head 10 in a longitudinal direction. As such, the bore may be described as a longitudinal bore 108. A fluid conduit 110 extends through the bore 108, as can better be seen in FIG. 1B. Although not shown, it will be understood that the fluid conduit 110 is fluidly connected to a suitable fluid reservoir, which supplies to the fluid conduit 110 the fluid that is atomised into a spray, in use.

[0067] In this first aspect, the fluid conduit 110 is in the form of a cannula, though in other aspects the fluid conduit 110 may be a conical nozzle, for example, as will be discussed further on.

[0068] The cannula 110 extends through the body 100 towards the front face 104, where the cannula ends in a cannula tip 112. In use, fluid from the fluid reservoir is flowed through the cannula 110 in a direction moving from the rear face 102 of the body 100 towards the front face 104, where it is ejected out of the distal tip 112 of the cannula 110.

[0069] Two pairs of ports 114, 116, as shown on the rear face 102, are provided for supplying gaseous medium to the front face 104 for atomising the fluid as it is ejected from the cannula tip 112, and controlling the resulting spray. The gaseous medium is preferably supplied at a pressure less than 1 MPa (i.e. 1 bar). The gaseous medium is preferably air, and for convenience will generally be referred to as such herein.

[0070] The first pair of (“atomising air”) ports 114 are arranged to supply air for atomisation of the fluid, and are fluidly connected to an annular chamber 132 within the body 100, as will be explained in more detail further on (e.g. see FIG. 2). The second pair of (“fan air”) ports 116 are arranged to supply air for controlling the resulting spray.

[0071] As can be seen in FIG. 1B, the front face 104 of the spray head is provided with a pair of opposing horns 118. Each horn 118 has one or more air outlets 120 (or “fan jets”) that are fluidly connected to one of the pair of fan air ports 116 on the rear face of the spray head 100. The air outlets 120 are angled inward, generally towards each other, such that air supplied to the air outlets 120 via the second ports 116 flows across the front face 104, thereby controlling the shape of the resulting spray of atomised fluid ejected from the cannula tip 112. The portions 122 of the front face 104 that extend between the horns 118 are, preferably, chamfered inward. If the portions 122 are chamfered, they help to allow surrounding air, which is drawn in during a spraying operation, to flow smoothly over the front face 104 of the body 100 without creating a negative pressure on adjacent surfaces that might otherwise cause ejected fluid to be pulled back onto those adjacent surfaces and drying. A central portion 124 of the front face 104 is both circular and generally flat.

[0072] The body 100 is formed of two segments 100A, 100B, which are separable along a “split line” A-A shown in FIG. 1A. As further shown in FIGS. 2 and 3, the body 100 of the spray head 10 can be formed, and preferably clamped, around a cannula 110, shown aligned between the two segments 100A, 100B, such that this fluid conduit is received, and preferably secured, within the bore 108 that is formed when the two segments 100A, 100B are combined. Each body segment 100A, 100B therefore defines part 108A, 108B of the bore 108. In other words, ideally, no single segment 100A, 100B of the body 100 defines a complete section of the bore 108. The bore 108 is thereby configured to conform to the shape of the fluid conduit for which the spray head 10 is to be used, which in this first aspect is a cannula 110.

[0073] Two sets of further air outlets (or “stabilising jets”) 126, 128 are provided on each body segment 100A, 100B for further stabilising and conditioning of the resulting spray from the atomised fluid, in use. These further air outlets 126, 128 are also fluidly connected to the annular chamber 132 in the body 100, mentioned above, which will be described further on.

[0074] The two segments 100A, 100B in this first aspect are designed and configured such that, when they are brought together (or “combined”) around a cannula 110 to form the complete body 100, a proximal end of the cannula 110 is clamped (i.e. “secured”) between them such that the distal tip 112 remains unsecured. Furthermore, a distal portion of the bore 108 is configured to widen in the location of the distal cannula tip 112 (i.e. the tip of the fluid conduit) such that an annular gap (or “air passage”) 130 is provided around the secured cannula 110. In use, air from the annular chamber 132 (not shown), which is fed by the port 114 in the rear face 102 of the body 100, is flowed through the annular gap 130 to atomise fluid ejecting from the cannula tip 112.

[0075] While an annular gap 130 is used in this example, other configurations for directing a balanced flow of air over the distal tip 112 of a fluid conduit 110 are possible. Alternatives might include a series of regularly spaced ports that surround the fluid conduit 110, or a helical flow path configuration, for example.

[0076] Radial projections 132 are provided on the inner wall of the bore 108, on each body segment 100A, 100B, in this example in the portion of the bore 108 that is widened to provide the annular gap 130, to help stabilise the unsecured cannula tip 112 and ensure that it is concentric within the bore 108. The radial projections 130 extend inwards and may also extend longitudinally along the wall of the bore 108.

[0077] Another view of the front face 104 of the spray head 10 is shown in FIG. 4, with sections A-A and B-B indicated which are shown in FIGS. 5A and 5B, respectively.

[0078] Section A-A, in FIG. 5A, is a sectional view through the body 100 that passes through the fan jets 120 in the horns 118 and the stabilising jets 128 provided on the front face 104 of the spray head 10.

[0079] This view shows the annular chamber 132 mentioned above, which is (also) formed when the two segments of the body 100 are combined. Thus, each of the boy segments 100A, 100B defines part of the annular chamber 132. The annular chamber 132 is supplied with air from the atomising air port 114 on the rear face of the body 100, as can be seen in Section B-B of FIG. 5B. In turn, the annular chamber 132 supplies air to both sets of stabilising jets 126, 128, and, importantly, also through the annular gap 130 between the unsecured distal tip 112 of the cannula 110 and the bore 108 for atomising fluid ejected from the distal tip 112.

[0080] It can also be seen in Section A-A how air may be supplied from the fan air ports 116 in the rear face 102 to the fan jets 120 in the horns 118. By using a suitable valve to control the flow of air to the horn 118, the shape of the spray may be controlled. If no air is flowed from the fan jets 120, then a circular spray is produced due to the lack of “squeeze” effect provided by the fan jets 120.

[0081] Section B-B, in FIG. 5B, is a sectional view through the body 100 that passes through the atomising air ports 114 shown in the rear face 102 of the body 100. As mentioned above, it can be seen how air is supplied to the annular chamber 132 from the atomising air ports 114 via fluid conduits that connect there between.

[0082] In both FIGS. 5A and 5B, it can clearly be seen how a distal part of the cannula 110 is secured in the bore 108 between the two segments of the body 100, with the distal tip 112 of the cannula 100 left unsecured. In this embodiment, the tip 112 extends just past the front face 104 of the body 100, but in other embodiments it could be secured within the body 100 such that it is approximately flush with the front face 104.

[0083] FIG. 6 shows various sectional views of a spray head 10 to assist with visualising the present invention. The body 100 of the spray head 10 can be seen both with a cannula 110 (i.e. the fluid conduit) received within the bore (not visible) of the assembled body 100, in particular sectional view B-B, and also without said fluid conduit received in the body 100, in particular sectional views C-C and D-D, such that the annular chamber 132 and its particular configuration within the body 100 can be better understood.

[0084] In sectional view B-B, the annular chamber 132 that is formed when the segments are brought together is clearly visible, as are the atomising air ports (and their connecting channels) 114 and the jet air ports (and their connecting channels) 116.

[0085] In sectional views C-C and D-D, it can be seen that, in this example, each body segment 100A, 100B comprises a wall portion 134 that extends from the annular chamber 132 to the front face 104 of the body 100, adjacent the (portion of the segment 100A, 100B that defines the) bore 108. The central portion 124 of the front face 104 comprises a chamfered “wall” portion 136 that extends away from the annular chamber 132, and is chamfered to slope upwards towards the front face 104. The chamfered wall portion 136 directs the airflow inward towards the fluid being ejected from the distal tip 112 of the cannula 110 for more effective atomisation.

[0086] The atomisation of fluid is performed in a manner well-known in the state of the art. The present invention allows the spraying process to be automated such that the two segments 100A, 100B of the body 100 are motivated by a machine (e.g. actuator) to be secured around a fluid conduit that is fluidly connected to a cartridge, syringe, feed line or other suitable fluid supply to form the complete spray head 10. The spray head 10 can then be operated automatically by the machine.

[0087] FIG. 7 shows an example of such an arrangement, in which a spray head 10 comprises two separable segments 100A, 100B that are each mounted to moveable fingers 210A, 210B, respectively, of an actuator 200. The actuator fingers 210 are arranged to be motivated by the actuator 200 to move between open and closed positions, whereby to separate or assemble the spray head, respectively.

[0088] In this example, a “syringe” type fluid reservoir 300 provides a supply of fluid to an attached cannula 110 (i.e. fluid conduit). The syringe 300 comprises a cylindrical cartridge 310 that acts as a fluid reservoir, and a plunger (or piston) mechanism 320 deployed within the cartridge 310 that is moveable relative to the cartridge 310 to drive fluid out through the cannula 110 that is fluidly connected to 310.

[0089] The plunger mechanism 320 may be used to grab the cartridge 300 of the syringe 310 internally and thereby move it into and out of the actuator (or mechanism) 200 that holds the cartridge 310, in use. A rubber sleeve (e.g. bellows, not shown) may be provided at the distal tip of the plunger mechanism 200, which can be expanded under air pressure to grip the interior walls of the cartridge 310 of the syringe 300 internally to secure the cartridge 300 to the plunger mechanism 200, for example where the plunger mechanism 200 enters just inside the cartridge 310.

[0090] Extended travel of the plunger mechanism 200 can carry the syringe 300 out through the open end face of the body 100 of the spray head 10. The plunger mechanism 200 (i.e. carrying the cartridge 310) can then be retracted to a position between the clamping mechanism 200 whereby it stops before the tip of the fluid conduit 110 reaches the end face of the spray head 10. The distal tip of the fluid conduit 110 can thus be clamped and released between the body segments 100A, 100B before it reaches the end face of the spray head (and the spray head bore 108) such that the distal tip of the fluid conduit extends out beyond the end face of the spray head 10.

[0091] When the actuator 200 is controlled to close the actuator fingers 210, they are brought together around the cartridge 310 of the syringe 300, thereby securing it between the fingers 210. At the same time, the two segments 100A, 100B of the spray head 10 are brought together (i.e. located) around the cannula 110 to form the complete (i.e. assembled) body 100, thereby securing the cannula 110 within the longitudinal bore (not visible) that is formed within the body 100 as a result of the two segments 100A, 100B coming together. The extent to which the cannula 110 protrudes or extends from the front face of the spray head 10 can be controlled by the position that the syringe 300 is located within the fingers 210.

[0092] An advantage of such an arrangement is that a plurality of cartridges may be arranged in racks in a robot cell, which the machine can use interchangeably simply by clamping the spray head body 100 to the fluid conduit of a desired cartridge and operating it to generate fluid spray, and then swapping the cartridge out for another one simply by returning the used cartridge to the rack and releasing the fluid conduit of the cartridge, and then securing the body 100 to the fluid conduit of a different cartridge. Similarly, multiple feed lines may be arranged in racks in a robot cell, similar to fuel lines at a fuel (or “gas”) pumping station, and the respective pump triggered when a particular feed line is selected for use by the robot.

[0093] Alternatively, the body 100 may be hand-assembled to the fluid conduit of a desired cartridge, or similar, and hand-operated. In this arrangement, a simple clamping mechanism (not shown), such as a toggle clamp (e.g. a mole wrench), may be secured or clamped around the separable segments of the body 100 when combined, to prevent them from separating and releasing the fluid conduit, in use. In this embodiment, a battery operated screw might control movement of a piston within the cartridge to provide a flow of fluid to the fluid conduit and an electric turbine might provide a stream of air through the body 100.

[0094] FIGS. 8A to 8C show examples of three different types of cannula 240, 340, 440, which may be used with a spray head 10 as described herein.

[0095] In FIG. 8A, an insert 250 is shown inserted into the tip 242 of the cannula 240. The insert 250 has radial fins and/or a fluid nozzle to atomise the fluid as it is ejected from the distal tip 112 of the cannula 240 and enters the atomising air stream. The radial fins can help to ensure that the unsecured tip 242 of the cannula 240, when received within the bore 108 of the spray head 10, remains concentric with the bore 108. Such an insert 250 may be useful for an “air-assist” function.

[0096] FIG. 8B shows a cannula 340 having a flattened tip 350, which can be used to generate a spray having a particular desired shape. Furthermore, forcing the fluid through this confined space helps both to atomise and shape the fluid spray.

[0097] FIG. 8C shows a cannula 440 that contains three smaller “sub” cannulas 450a, 450b, 450c. For example, if fluidly connected to a cartridge having three separate fluid chambers having separate pistons for selectively driving fluid from each chamber, or indeed three different cartridges or three separate feed lines, the sub-cannulas 450a, 450b, 450c can each be fluidly connected to a respective fluid chamber such that multiple fluid sprays can be generated on demand, without having to swap out the cannula 440. In this way, different coloured fluids may be provided via different fluid lines or an array of cartridges with suitably bent cannulas, for example, via the single cannula 410 held retained within the spray head body 100. A static mixing tube (not shown) for mixing fluid and hardener at the last moment before spraying could also be used.

[0098] FIGS. 9 and 10 show a spray head 10′ according to a second aspect, which is configured for use with a fluid conduit in the form of a nozzle 510, and preferably a conical (or tapered) nozzle. As described above for FIG. 2 and FIG. 3, the body 100′ is formed of two separable segments 100′A, 100′B, which are shown aligned with a conical nozzle 510 around which body 100′ of the spray head body 10′ is formed. As with the first aspect described above, the bore 108′ is configured to conform to the shape of the fluid conduit for which the spray head 10 is to be used, which in this first aspect is a conical nozzle 510. Other than having a different configuration, which is specific for the particular fluid conduit 510 for which it is to be used, the spray head 10′ of the second aspect is essentially the same as the spray head 10 of the first aspect described above, and as such there is no need to describe it in detail again here.

[0099] FIG. 11 shows an example of an arrangement by which a spray head 10′ according to the second aspect can be operated automatically by a machine, similar to what is shown in FIG. 7 and described above. Again, as the majority of features are common to both arrangements, there is no need to describe them again in detail here. As shown, the second aspect differs in that the fluid conduit 510, which is fluidly connected to the cartridge 310′ of the syringe 300′, is in the form of a conical nozzle, and the shape of the longitudinal bore of the formed body 100′ is therefore adapted or configured accordingly to correspond with the shape of the nozzle 510.

[0100] FIGS. 12 and 13 show two examples of fluid conduits configured as conical nozzles 510 for use with the spray head 10′ according to the second aspect.

[0101] FIG. 12 shows a generally conical (or tapered) nozzle 510. The nozzle 510 is configured to have a Luer lock 520 connection with the cartridge 310′ of a syringe 300′. The nozzle 510 needs to project the outlet for the fluid into the atomising airflow away from the reservoir volume, for example the cartridge 310′ of a syringe 300′. A conical 510 nozzle reduces the pressure drop along its length, thereby reducing the force required to be applied to move the plunger mechanism 320 for efficient atomisation of the fluid at the orifice 512. The shape of the nozzle 510 creates an acceleration profile in the fluid and characterises the exit velocity. The flow profile imparts shear induced viscosity changes to the fluid prior to atomisation. The shape of the nozzle 510 can be adjusted to suit the fluid's rheology, the required condition on exit and the loading on the mechanism that deploys the fluid (e.g. the plunger mechanism 320 which is inserted into the cartridge 310′ of a syringe 300′ to deploy the fluid contained therein, and optionally to move the cartridge 310′ into position).

[0102] FIG. 13 shows the nozzle 510 of FIG. 12 having a wear resistant tip 550, which may be either moulded as one piece with the nozzle 510 or provided as a separate attachment. As the change in cross-section becomes more abrupt, the nozzle 510 may wear too quickly. In this case, the wear resistant tip 510 can be added to, or moulded into, the nozzle 510. In the extreme, tips 550 with very small restriction diameters require high pressures which can initiate fluid atomisation at the “pinch point”, orifice or at the exit, with or without air assistance (e.g. “air-mix” or “airless” systems).

[0103] In other examples, the nozzle may have a bayonet or screw fitting, for example, to secure it to the cartridge 310′.

[0104] It will be understood that the two aspects described above are provided purely by way of example, and alternative configurations and modifications of detail can be made within the scope of the invention. For example, any feature in a particular aspect described herein may be applied to another aspect, in any appropriate combination.

[0105] It should also be appreciated that particular combinations of the various features described and defined in any aspects described herein can be implemented and/or supplied and/or used independently. Furthermore, it should be noted that any apparatus feature described herein may also be provided as a method feature, and vice versa.