JP3162487B2 - Spray nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates generally to liquid household products, cosmetics, and physiologically acceptable products .
The invention relates to a spray nozzle for use in a hand-held sprayer, such as a so-called aerosol and pump atomizer, intended for product (e.g. pharmaceutical) applications.

[0002]

2. Description of the Related Art Aerosol atomizers are used in a wide range of products,
It is used worldwide to apply a wide range of products such as hair sprays, furniture polishes, detergents, paints, pesticides and pharmaceuticals. To date, chlorofluorocarbons (CFC's) have been the most common propellants used in aerosols. This is because chlorofluorocarbons are inert, compatible with a wide range of products, can be easily liquefied at low pressures, maintain a nearly constant product flow rate and produce droplets having an average diameter in the range of 3 μm to 100 μm or more. This is because a spray can be created. However, CF
C's were identified as likely to be the cause of the depletion of the ozone layer that protects the earth in the 1970s, and in 1987 many countries signed the Montreal Protocol to progressively eliminate the use of CFC's. Subsequently, alternative propellants, for example liquefied hydrocarbon gases such as butane, and carbon dioxide, which did not dissolve in the product, were introduced. However, they are flammable, or harmful to the environment, or have reacted with products, and these propellants have gradually disappeared.
Many aerosols and hand-pumped atomizers have been developed which are energized by compressed gas (eg nitrogen, air) and the performance of these atomizers has been adequate for most applications.

A major disadvantage of non-CFC's nebulizers is that the smallest droplets that can be produced have a diameter of about 40 μm.
Despite the considerable development of so-called machine-assisted nozzles, the use of high-pressure (c 15 bar) pumps, and low viscosity / surface tension product formulations, 40 μm is reached with prior art methods and equipment. It seemed to be a lower limit. Such as ultrasonic nebulizer and disk rotary generator,
There are aerosol generators used for research and in hospital applications, but none were suitable for portable, convenient atomizers.

In addition, it is possible to create droplets of about 5 μm in diameter by passing a high-pressure liquid through very small holes (5 μm to 10 μm in diameter), but these methods are unsuitable and uneconomical for mass production. Was. The main reason was that it was difficult to create very small holes in the appropriate material, which required extreme cleanliness in the manufacture of the parts to prevent the holes from clogging, and which should be sprayed. This is because ultrafiltration of the liquid is required.

In veterinary treatment inoculations and some human inoculation applications, a high pressure ("intra-dermal injection") injection of a drug jet through the skin without the use of a needle is used. A 125 bar (500 bar) spring or gas operated pump (so-called needleless syringe) is commonly used to turn the jet into a spray to administer the drug to the nasal passages of large animals such as pigs. Attachments are available. However, the minimum size of the droplets obtained is of the order of 40 μm, and the use of these injectors is limited.

[0006] Compressed air atomizers, such as air brushes, and commercial paint sprayers consume large amounts of air, for example, a gas-to-liquid ratio of 30,000 to obtain 5 µm droplets in water.
More than one to one is required, which is not practical for a convenient portable atomizer. Nevertheless, there are some applications that rely on smaller droplet sizes for maximum efficiency. Space sprays, such as insecticides for flying insects, should ideally contain droplets of 20-30 μm in diameter in order to remain airborne over a long period of time, and For inhalers for inhaling metered doses used in the treatment of respiratory disease, the aerodynamic particle size should be such that the droplets can penetrate and adhere to the trachea, bronchi and alveoli areas of the lung. 15 μm or less, preferably 5 μm
μm or less. For a sprayer consisting of droplets having a predetermined range of sizes, at least 5% of the weight of the droplets must have an aerodynamic particle size of 6.4 μm or less,
Preferably, at least 20% of the weight of the particles has an aerodynamic particle size of 6.4 μm or less.

In addition, the inhaler may be designed to deliver the drug to the alveoli of the lungs in order to create a path for the drug that is poorly absorbed from the gastrointestinal tract to be adsorbed into the bloodstream. To reach the alveoli, it is important that the aerodynamic size of the particles be less than 10 μm, preferably between 0.5 μm and 5 μm. Many drugs used in the treatment of respiratory disease are insoluble in vehicles such as water and are applied as a suspension. These drugs are made in a size that can be inhaled from 1 μm to 5 μm. Particles of this size tend to pinch very small pores (5-10 μm) used in known devices to generate droplets about 5 μm in diameter.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spray nozzle design that can be used by itself to provide a nozzle that produces a spray of droplets of a size suitable for inhalation without the use of a liquefied gas propellant. It is to provide. However, the present invention has an average diameter of 0.5 μm to 100 μm
It could be used to provide a nozzle that produces a spray of droplets in the range

[0009]

According to the present invention, an orifice forming means for forming an orifice and a closing member for the orifice are provided in a spray nozzle for forming a spray of liquid droplets by passing a liquid through the nozzle under pressure. Wherein the orifice defining means and the closure member have a first position in which the closure member cooperates with and closes the orifice and the closure member is spaced from the orifice defining means to define a gap therebetween. Relative to each other relative to each other between the second position and further restricting the relative movement between the orifice forming means and the closing member so that the width of the gap exceeds the width producing a fine spray. A nozzle is provided having a stop to prevent it. The present invention mainly comprises
Although directed to inhalers and manual pumps for inhaling metered doses, they can also be applied to other applications requiring small droplets, for example, certain industrial processes.

In one embodiment of the invention, the nozzle has a circular orifice that is hermetically closed by a spring-loaded ball. Under the action of the liquid under pressure, the ball is displaced from the orifice by an amount determined by the stop. The stop may be fixed or adjustable, and the fluid exits as a thin circular sheet through the gap thus formed. As the liquid sheet expands, the liquid sheet becomes thinner and its outer edge breaks to form droplets. The droplet diameter depends on the size of the gap, the pressure of the liquid, and the physical properties of the liquid. When the pressure of the liquid drops below a predetermined level, the ball is pressed hermetically by a spring onto the orifice, thus:
Waste ingress, product evaporation and air pollution are prevented.

In another embodiment of the invention, the liquid to be sprayed is flowed through a spherical surface and through a gap formed between the spherical surface and the perimeter hole of the plate. The plate is preferably made of a spring material and is arranged as a normally closed valve in sealing contact with the spherical surface. Under the action of the liquid under pressure, the plate is pushed away from the spherical surface by the amount determined by the stop. The stop may be fixed or adjustable, and the fluid exits as a thin circular sheet through the gap thus formed. As the liquid sheet expands, the liquid sheet becomes thinner and its outer edge breaks to form droplets. The droplet diameter depends on the size of the gap, the pressure of the liquid, and the physical properties of the liquid. When the pressure of the liquid drops below a predetermined level, the spring plate returns to its original position and seals against the spherical surface. Thus, debris ingress, product evaporation, and air pollution are prevented.

Although the foregoing has referred to the use of a ball or spherical surface in conjunction with the circular orifice of a plate or nozzle, other shapes, such as conical surfaces that cooperate with circular holes, may be used. Is also good. The detailed contours of the faces and holes are determined in part by the required spray pattern,
While the present invention provides for all combinations of faces and holes, it is preferred that the cross-section of at least one of the components is variable such that the gap between the components is opened and closed as a result of relative movement. . The stop ensures that the gap is of approximately constant size when the components are completely separated, so that a uniform spray is obtained by passing the fluid over the length of the gap. The width of the gap is preferably about 5 μm.
The value of the ratio L / D of the gap length L to the gap width D is
Preferably it is 1 or less, more preferably 0.5 or less. The "length L " of the gap refers to the distance that the liquid must travel to pass through the gap. Also, the gap
The “width D” between them is in the direction orthogonal to the length L direction of the gap.
Means the smallest dimension that can be measured.

The surface finish of the cooperating components in the area of the gap must be sufficiently precise so as not to adversely affect the droplet size and spray pattern. For example, if one component has a groove, the liquid flow exits the groove. This may not have the necessary properties and may reduce the pressure of the liquid enough to adversely affect the quality of the spray coming out of the rest of the gap.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a ball 1 is elastically pressed by a compression spring 6 to a predetermined position hermetically disposed on a circular orifice 3 of a nozzle 2. Stop means 5 are located on the longitudinal axis of the ball and orifice.
The stop means Translucent between the surface 9 and the ball 1 surface
It has 8 spaces . The nozzle 2 is in hydraulic communication with an application means (not shown) and contains a liquid 7 to be sprayed.

Referring now to FIG. 2, FIG. 2 shows the same components as in FIG. 1, in which pressure is applied to the liquid 7 by the application means and the ball 1 springs until it stops against the face 9 of the stop means 5. From the circular orifice 3 against the force of Thus, the ball 1 is formed an amount only moved a gap 10 which is controlled by the gap 8, the gap 10
Is smaller than the gap 8 by an amount determined by the ratio of the diameter of the ball 1 to the diameter of the circular orifice 3. The liquid 7 exits the gap 10 in a circular sheet having a thickness initially determined by the size of the gap 10.
As the liquid sheet expands, the liquid sheet becomes thinner until the surface tension of the liquid can no longer maintain the integrity of the sheet, and the periphery of the sheet breaks into small droplets. The size of the droplet is controlled by the size of the gap 10 and the speed of the liquid. The speed of the liquid depends on the pressure created in the application means. If the pressure in the liquid is high enough to overcome the viscous drag created by the small gap, a small gap 10 will produce small droplets and accelerate the liquid to form a thin sheet. (If the pressure is too low, the liquid will only overflow from the gap.) Specifically, the gap length L and the gap width D
It is preferable that the value of the ratio L / D to
And more preferably 0.5 or less. This place
In this case, as described above, the “length L” of the gap passes through the gap.
Means the distance the liquid has to travel to
The “width D” of the gap is the direction orthogonal to the length L direction of the gap.
Means the minimum dimension in the direction (for example, reference numeral 1 in FIG. 2)
The dimension indicated by the arrow 0 corresponds to the width D of the gap 10.
). When the pressure in the liquid 7 has disappeared, the ball 1 is again sealingly engaged with the orifice 3 by the spring 6. The contact line between ball 1 and orifice 3 is preferably very thin,
This can easily be done by chamfering the nozzle at 4 so as to leave the knife edge.
This has the added advantage of providing a wider spray angle Z than is possible with orifices having rectangular edges.

FIGS. 3 and 4 show a modification in which the stopper 5 is replaced by a stopper 5a of a modification. The stopper 5a has a recess 5b, in which 6 is accommodated. When the nozzle is moved from the closed position shown in FIG. 3 to the open position shown in FIG. 4, the ball 1 seats itself on the open end of the recess. The guides that do this form an even tubular gap between the orifice 3 and the ball, and precisely align the ball with respect to the end of the conduit 2. The spray produced is thus substantially uniform both in distribution around the gap and in droplet size.

Modifications are shown in FIGS. In this case, FIG. 5 shows a spherical surface 20 located at the outer edge of the discharge conduit 21 containing the liquid 22 to be sprayed. Spring plate with a circular orifice 25 (flexible diaphragm
24 ) is held against the spherical surface 20 such that the circular orifice 25 is in sealing contact with the spherical surface 20 and the outer edge of the spring plate 24 is in sealing contact with the abutment surface 26 of the conduit 21; , So that the liquid 22 does not pass through. A plate 27 having a circular hole 29 is incorporated on the outer surface of the spring plate 24 such that the hole 29 is coaxial with the orifice 25. Stops or recesses 30 of plate 27
Is a gap 28 between the spring plate 24 and the plate 27.
And an assembly composed of two plates is a holding member 3
3 keeps the abutment 26 in sealing contact. The holding member 33 is preferably crimped as shown.

Referring to FIG. 6, the liquid 22 is pressurized by dispensing means (not shown) to force the plate 24 from the spherical surface 20 against the inherent pressing force provided by the plate 24 being a spring plate. Push and release, circular orifice 25
A gap 32 is created between the ball and the spherical surface 20. The size of the gap 32, hole 29 of the size and the plate 27 of the gap 28
Is determined by the diameter of Of these, plate 27
The diameter of the bore 29 determines how much the spring plate 24 can flex. The liquid exits the gap 32 as a thin circular sheet, the periphery of which breaks into droplets as described above. The edge of the circular orifice of the spring plate 24 is shown in FIG.
The bevels may be chamfered, as shown in Figure 1, which allows for a wider spray than is possible with orifices having rectangular edges. The spring plate 24
As shown in FIG. 8, it may have a fold coaxial with the orifice 25, which facilitates deflection of the spring plate. When pressure is removed from the liquid 22, the spring plate 24 returns to sealing contact with the spherical surface 20.

5 and 6, the spherical surface 20 is schematically shown as being provided at the end of a rod, which requires means (not shown) to support the rod with respect to the liquid discharge conduit 21. Is done. 9 and 10 show a disk 50 fixed to or integral with the inner wall of the conduit 21.
A modification in which a spherical surface 20a is formed thereon is shown. The disc 50 is provided with at least one port 51 through which liquid can pass from inside the conduit 21 to the plate 2.
4 to the area directly below. 11 to 13
1 shows a spray device incorporating a spray nozzle according to the invention.
It is intended to be used as an inhaler. This device has a reservoir 60 for a liquid 61. Liquid 61
Is a physiologically acceptable liquid, for example,
It may consist of an aqueous suspension of a medicament suitable for treating conditions such as asthma. The lower end of the reservoir is constituted by a piston 62 that is slidable in the length direction in the reservoir.
Below the piston is at least one orifice 6 which allows air to enter the space below the piston.
4 is provided.

The upper end of the reservoir has a neck portion 65 to which a closure member 66 is fixed. The closure member portion 67 extends into the neck and the O-ring seal 68 is
A seal is formed between and the part 67. The closure member 66 has a through passage 69 in which a tube 70 is fixed in the upper part of this passage. The lower part of the passage constitutes an orifice 71,
Above this orifice is a tapered portion which constitutes a seat on which the ball 72 of the check valve sits. This ball is pressed against a seat by a compression spring 73. Exit member 7
4 so that the closing member 6 is movable with respect to the closing member 66.
6 attached. The outlet member 74 has a substantially cylindrical part 75, the lower end of which engages on the closure member 66. The component 75 is not separated from the closure member 66 by the interengagement of the flanges 76 and 77. The outlet member 74 further has a spout 78 through which a user can aspirate through the spout. In the case of a nasal aspirator, the spout 78 is replaced with a suitable nasal outlet.

In the area of connection between the cylindrical part 75 and the outlet 78, the outlet member 74 has an inwardly extending wall 79 which serves to hold the spray mechanism 80. The spray mechanism comprises a block 81 having a lower hollow portion 82 and a lower hollow portion 82.
Surrounds the upper end of tube 70 and freely enters cavity 83 at the upper end of closure member 66. The hollow portion 82 has an outwardly extending flange 84 at its upper end, and a compression spring 85 is mounted between the flange and the closure member 66. The interior of the hollow portion 82 is in communication with a spray nozzle 90 according to the invention via a passage 86. This is shown enlarged in FIG. As can be seen from FIG. 13, this corresponds substantially to that shown in FIGS. 9 and 10, and has a spring plate 91 cooperating with a spherical surface 92 formed on a disk 93.
The disk 93 has at least one through port 94.

In operation, the user places his mouth over the spout 78 and connects the reservoir 60 and outlet member 74 together with the compression spring 8.
Squeeze against the force of 5 and bring the device to the state shown in FIG. During this operation, the ball 72 is filled with liquid at the orifice 71.
The tube 70 acts as a piston that discharges a portion of the liquid above the ball through the nozzle 90 without leaving the reservoir 60 through. The liquid is sprayed at the nozzle 90. The amount of liquid thus discharged constitutes a metered dose, the metering being effected by the stroke of the piston. The user aspirates this spray. When the user stops holding reservoir 60 and outlet member 74 together, spring 85 pushes them apart. This creates a suction effect in the tube 70, which separates the ball from its seat and allows liquid to be replenished from the reservoir through the orifice 71 through the nozzle 90. As the volume of liquid in the reservoir decreases, the piston 62 slides upward with the atmospheric pressure acting below it.
Air passes through port 64 to the underside of the piston.

FIG. 14 shows another modification of the spraying device.
This figure shows the device in the discharge position. In this embodiment, a valve of a similar design to the valve used as the spray nozzle is also used as the non-return valve. FIG. 14 shows the actuator 101 hermetically arranged on a hollow stem 104 integral with a hollow piston 107. The piston 107 is hermetically arranged in a cylinder 115, which is formed as an internal part of the pump body 108. The body may be closed 1 by a snap fit or other convenient holding method.
05, a gasket 106 forms a seal between the stem 104 and the closure 105. Gasket 1
06 flexes freely with axial displacement of the piston and stem while maintaining a seal. Piston 107
A plurality of cantilever springs 109 formed integrally with the piston act on a conical surface 110 formed on a lower portion of the pump body 108 to press the piston outward. The piston is closed 105
The abutment 116 closed on the gasket 106 supported by the inside of the ball prevents the ball body 108 from coming out.

The lower end of pump body 108 includes a spherical surface 111. The flexible diaphragm 112 and its circular hole are sealingly disposed within the pump body 108 such that the edge of the diaphragm hole sealingly engages the spherical surface 111. The combination of diaphragm 112 and surface 111 acts as a normally closed check valve 120. The bottom portion of the pump body 108 terminates in a diameter adapted to hermetically hold the dip tube 113. The conduit formed by the immersion tube 113 and the lowermost part of the pump body 108 communicate with a ring 119 formed between the spherical surface 111 and the diaphragm 112 via one or more ports 117. The actuator 101 has a spherical surface 103 and a flexible diaphragm 102 with a circular hole, the edges of which are spherical surface 103
And sealing engagement. Diaphragm 102 is hermetically disposed within actuator 101 in a snap-fit or other convenient manner, and the combination of diaphragm 102 and surface 103 acts as a check valve and spray nozzle 121.
Hollow stem 104 communicates with annulus 114 via port 108. In operation, the actuator is pushed back several times to prime the pump, valves 120 and 121 cooperate to draw liquid from a reservoir (not shown) and drain liquid from the spray nozzle.

FIG. 15 illustrates a spray nozzle provided with means for adjusting the gap through which the liquid passes, unlike the embodiment described above. The nozzle has an externally threaded body 201 for receiving a threaded cap 202. The cap can be adjusted to change the gap 203 formed between the face 204 of the cap and the flexible diaphragm 205. In this way, the discharge characteristics can be easily changed. For example, the spray can be adjusted from fine to coarse droplets. As used herein, the term "liquid" refers to an aqueous liquid or aqueous (water)
Solutions, suspensions and emulsions, and non-aqueous liquids
And non-aqueous (water-free) solutions, suspensions and emulsions .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of basic components in a normal, non-pressurized relationship, illustrating the principles of the present invention.

FIG. 2 is a view similar to FIG. 1, showing the components in an actuated position.

FIG. 3 is a diagram showing a modification of the embodiment of FIG. 1;

FIG. 4 is a diagram showing a modification of the embodiment of FIG. 2;

FIG. 5 shows a modification of the principle of the invention in a closed position.

FIG. 6 shows a modification of the principle of the invention in an open position.

FIG. 7 is an enlarged partial cross-sectional view showing an associated portion of main components shown in FIGS. 5 and 6.

FIG. 8 is a sectional view of a modification of the spring plate used in the embodiment of FIGS. 5 and 6;

FIG. 9 is a view showing a modification of the embodiment of FIG. 5;

FIG. 10 is a diagram showing a modification of the embodiment of FIG. 6;

FIG. 11 is a diagram of a spray device incorporating a nozzle according to the invention for use as an inhaler.

FIG. 12 is a diagram of a spray device incorporating a nozzle according to the present invention for use as an inhaler.

FIG. 13 is an enlarged view showing a nozzle used in FIGS. 11 and 12;

FIG. 14 shows another form of spraying device incorporating a nozzle according to the invention.

FIG. 15 is a view of an embodiment of a nozzle whose gap size is adjustable.

[Explanation of symbols]

 1 Ball 2 Nozzle 3 Orifice 4 Garbage Collection Container 5 Stopping Means 6 Spring 7 Liquid 8 Gap 9 Surface 10 Gap

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-145809 (JP, A) Tokuhyo Hei 5-506608 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05B 1/06 B05B 1/02 B05B 1/30-1/32

Claims (20)

(57) [Claims] 1. A spray nozzle for creating a spray of droplets by passing a liquid through a nozzle under pressure, comprising: an orifice forming means defining an orifice; and an orifice closing member. The member is relative to one another between a first position in which the closure member cooperates with and closes the orifice and a second position in which the closure member is spaced from the orifice forming means and defines a gap therebetween. And a stop for limiting the relative movement between the orifice forming means and the closing member so that the width of the gap does not exceed a predetermined fine spray width. Having a nozzle. 2. The nozzle according to claim 1, wherein the orifice is circular. 3. The nozzle according to claim 2, wherein the closure member has an at least partially spherical surface arranged to cooperate with the orifice. 4. The nozzle according to claim 1, wherein the orifice forming means is a flexible diaphragm. 5. The nozzle according to claim 4, wherein the diaphragm is provided with at least one fold surrounding the orifice, thereby increasing the flexibility of the diaphragm. 6. The nozzle of claim 4 or claim 5, wherein the stop comprises an annular ring having a stop surface adjacent to, but spaced from, the diaphragm. 7. The method according to claim 1, wherein the closing member is a spherical ball.
The nozzle according to any one of claims 6 to 6. 8. The nozzle according to claim 1, wherein the orifice forming means and the closing member are relatively movable with respect to each other under the action of a force exerted by the pressure of the liquid. 9. The orifice has a chamfered peripheral surface,
9. The nozzle according to any one of the preceding claims, wherein the direction of the chamfer is such that the length of the gap is reduced. 10. The nozzle according to claim 1, wherein the width of the gap is on the order of 5 μm. 11. The nozzle according to claim 1, wherein the orifice forming means and the closing member are pressed to the first position. 12. The nozzle according to claim 11, wherein said pressing force is an elastic pressing force. 13. The nozzle according to claim 12, wherein the elastic pressing force is provided by an orifice component that is elastically movable. 14. A spray nozzle according to any one of claims 1 to 13, a supply source of said liquid, and means for supplying a pressurized liquid from said supply source to said nozzle. A spraying device having 15. The apparatus according to claim 14, further comprising a metering means for causing the liquid passing through the nozzle to be a metered amount. 16. The device according to claim 14, wherein the liquid is a physiologically acceptable aqueous liquid. 17. The device according to claim 14, wherein the liquid is a physiologically acceptable non-aqueous liquid. 18. The device according to claim 16, wherein the liquid comprises a medicament suitable for inhalation. 19. The device according to claim 18, wherein said liquid contains said medicament in suspension. 20. The device of claim 18, wherein said liquid contains said medicament in solution.