Vibrating orifice atomizer

Abstract

An atomizer (1) has an aerosol generator (5) mounted in a housing (3) and has a vibratable orifice plate (41) mounted to an annular support (40) and having a vibration generator piezoelectric body (46) attached thereto. A downstream elastomeric seal (43) is mounted between the housing and the gasket (40) on the side of the orifice plate opposite the liquid supply container (21). An upstream elastomeric seal (48) is in the form of a gasket and is mounted between the gasket (40) and the housing container (21) and has an opening (72) that forms part of the throat (8) above the orifice plate (41). The gasket (48) has a gasket shaped body (70) that extends radially from a downstream extending edge (71) adjacent the orifice plate (41). There are two upwardly directed ridges (74, 75) for engagement with the surface of the housing (21) and the gasket is configured such that when under axial compression the inner surface of the opening (72) tapers inwardly in the flow direction to form a funnel shape. The gasket can be textured with sufficient surface roughness to discourage bubble adhesion to the surfaces exposed to the throat.

Description

Technical Field

[0001] This invention relates to atomizers of the type having a vibrating orifice plate aerosol generator. Background Technology

[0002] Our prior specification WO2012046220A describes an aerosol generator having a funnel-shaped housing top forming a container, which is inclined relative to the axis of a tubular lower portion. An orifice plate (“AP”) is attached to a gasket-shaped support having a ring-shaped piezoelectric vibrator. Electricity is supplied directly to the top of the piezoelectric element via a pin and to the bottom of the piezoelectric element via a gasket. This atomizer is highly effective.

[0003] However, vibrating plate atomizers naturally tend to draw in air through the center of the orifice plate during atomization. These bubbles, ranging in size from micrometers, can migrate to the walls of the atomizer throat above the orifice plate. Here, they may stagnate, merge, and form larger bubbles. These larger bubbles can reduce or interrupt atomization. Sometimes, tapping the atomizer can help release the bubbles and restart atomization.

[0004] Our previously published patent specification WO2016151029A describes a method for preventing bubbles, which includes providing physical features in the inner surface of a container to physically prevent bubbles from forming into large bubbles. EP3560604 (Microbase) describes an aerosol generator having an inner liner on the inner edge of a pad-shaped piezoelectric element. WO2014 / 133273 (KTMED) describes a liquid medication inhalation device. US2015 / 0375252 (DELBio,INC) describes a spray device, WO2019 / 214281 (TAIAN DALU) describes a medical nebulizer, and US2018 / 0193869 (United Therapeutics Corp) describes an adjustable aerosol delivery device.

[0005] The present invention aims to achieve improvements in the efficiency and consistency of liquid-to-aerosol conversion and / or more efficient automated manufacturing of atomizers. Summary of the Invention

[0006] The present invention provides an atomizer as set forth in claims 1 and 40 and their dependent claims.

[0007] The atomizer we describe includes: a liquid supply container, an aerosol outlet, and an aerosol generator, the aerosol generator comprising:

[0008] Vibrating orifice plate,

[0009] Annular support for the support plate.

[0010] Vibration generator attached to the ring support,

[0011] Electrical conductors used to transmit power to the vibration generator

[0012] A downstream resilient seal is installed on the side of the orifice plate opposite to the liquid supply container, between the housing and the annular support.

[0013] An upstream resilient seal is installed between the annular support and the housing container and has an opening above the orifice plate forming a throat.

[0014] In one example, the upstream resilient seal includes a gasket having a body and a downstream extending edge adjacent to an opening, the body extending radially from the edge in a generally annular shape. In one example, the gasket includes at least one upward-pointing ridge for engaging with a housing surface. Preferably, it has two or more upward-pointing ridges, and preferably, at least one of the ridges is circular in a plane, preferably concentric. In one example, the ridges have a height in the range of 0.1 mm to 0.5 mm, and the downstream extending edge has a depth in the range of 0.5 mm to 1.1 mm relative to the gasket body.

[0015] In one example, the upstream resilient seal is configured such that, under axial compression, the opening has an inner surface that tapers inward along the flow direction to form a funnel shape at the throat. In another example, the inner surface of the upstream resilient seal opening forms a continuation of the inner surface of the housing container when the seal is under compression.

[0016] In various examples, the pad body covers at least a portion of the annular support and preferably also covers at least a portion of the vibration generator. In one example, the pad covers and contacts the upper surface of the vibration generator, which is mounted to the top (upstream) surface of the support.

[0017] In various examples, the housing includes a retainer that engages with an aerosol outlet, and the aerosol generator is supported by the retainer. Preferably, the retainer snaps into the aerosol outlet. Preferably, the engagement between the retainer and the aerosol outlet is between the toes of the retainer engaging in a recess in the housing, and the engagement is aided by the compression and axial reaction force of the resilient seal. Preferably, the retainer includes an annular seat for a downstream resilient seal; and wherein a support, orifice plate, vibration generator, and gasket are supported above the downstream resilient seal. In one example, the retainer forms an annular seat for an upstream resilient seal, and preferably includes circumferential and axial tabs forming the sidewalls of the seat.

[0018] In various examples, the throat has a depth of at least 18 mm in the plane of the orifice plate. 2 Preferably at least 20mm 2 More preferably at least 25mm 2 More preferably at least 30mm 2 And more preferably at approximately 32mm 2 Up to 40mm 2 The area within the range. In one example, the area of ​​the throat in the plane of the orifice plate is at least twice the vibrating area of ​​the orifice plate.

[0019] In one example, the upstream resilient seal opening, when within the housing and compressed, has a diameter exceeding 5 mm, preferably exceeding 5.5 mm, and more preferably exceeding 6.0 mm. In another example, the upstream resilient seal opening has an axial dimension in the range of 1.8 mm to 3.0 mm, and preferably exceeding 2.0 mm.

[0020] In one example, the atomizer includes a pair of conductive spring pins for driving a vibration generator, and one or both of the pins extend through a hole in the liner.

[0021] In one example, the upstream resilient seal is medical-grade liquid silicone rubber, supplied as a two-component compound, which is mixed together and injected into a hot mold for curing. In various examples, the upstream resilient seal has a Shore hardness in the range of 20 to 80 Shore A, preferably 30 to 60 Shore A.

[0022] In various examples, the liner includes multiple downstream ridges. In various examples, the vibration generator is mounted to the upstream surface of the support, and at least one downstream extending ridge extends around the outer periphery of the vibration generator.

[0023] In various examples, the gasket extends radially to form an elastic seal between the plastic housing components, and the gasket may extend radially to completely cover the vibration generator; and in some examples, the gasket extends radially to completely cover the support; and it may extend radially to engage the housing at its outer edge.

[0024] In various examples, the upstream resilient seal has a surface roughness Ra value in the range of 1.6 μm to 3.2 μm on at least a portion of its exposed surface.

[0025] In various examples, the upstream resilient seal has a hydrophilic coating on at least a portion of its exposed surface.

[0026] In various examples, the retainer includes at least two opposing ramps for guiding the retainer into the housing.

[0027] We also describe a method for manufacturing an atomizer of any example having a retainer, the method comprising mounting an aerosol generator to the retainer and causing the retainer to move automatically toward the housing container until the retainer snaps into place on the housing, held in place by the axial elastic reaction forces of the upstream seal (48) and the downstream seal.

[0028] In various examples, the retainer includes at least two opposing ramps for guiding the retainer into the housing, and the action of moving the retainer toward the housing container is guided by the ramps to align it.

[0029] We also describe an atomizer comprising: a housing, a liquid supply container, an aerosol outlet, and an aerosol generator mounted within the housing and including:

[0030] Vibrating orifice plate,

[0031] Annular support for the support plate.

[0032] Vibration generator attached to the ring support,

[0033] Electrical conductors used to transmit power to the vibration generator

[0034] Downstream annular resilient seal, which is mounted on one side of the orifice plate between the housing and the annular support, and

[0035] An upstream resilient seal is mounted between the annular support and the housing and has an opening with an exposed surface forming part of the throat above the orifice plate, and at least a portion of said surface is roughened.

[0036] In various examples, at least a portion of the exposed surface has an average roughness ranging from 1.6 μm to 3.2 μm. In various examples, the exposed surface forms a funnel shape at the throat.

[0037] In various examples, the shell container forms a bend that widens from the throat, and said bend extends at an angle exceeding 40° relative to the axial direction. In various examples, the orifice plate has orifice diameters ranging from 2 μm to 6 μm. In various examples, the axial distance from the edge plane of the orifice plate to the bend ranges from 1.8 mm to 3.0 mm. In various examples, the axial dimension of the seal at the throat ranges from 1.5 mm to 3.0 mm.

[0038] Additional Statement

[0039] We also describe an atomizer that includes:

[0040] case,

[0041] Liquid supply container formed by a shell,

[0042] Aerosol outlet in the housing,

[0043] An aerosol generator installed in a housing, and comprising:

[0044] Vibrating orifice plate,

[0045] Annular support for the support plate.

[0046] Vibration generator attached to the ring support,

[0047] Electrical conductors used to transmit power to the vibration generator

[0048] A downstream annular resilient seal, installed between the housing and the annular support, is located on the downstream side of the orifice plate opposite to the liquid supply container.

[0049] An upstream resilient seal is installed between the annular support and the housing container and has an opening that forms part of the throat above the orifice plate.

[0050] Preferably, the upstream resilient seal is in the form of a gasket having a body and a downstream extending edge adjacent to the opening, the body extending radially from the edge in a generally annular shape. Preferably, the gasket includes at least one upward-pointing ridge for engaging with the housing surface. Preferably, it has two or more upward-pointing ridges. Preferably, at least one of the ridges is circular in a plane, and preferably concentric.

[0051] Preferably, the ridge has a height (relative to the liner body) in the range of 0.1 mm to 0.5 mm, and the downstream extending edge has a height (relative to the liner body) in the range of 0.5 mm to 1.1 mm. Preferably, the liner is configured such that, under axial compression, the inner surface of the opening tapers inward along the flow direction to form a funnel shape.

[0052] Preferably, a portion of the inner surface of the opening is formed by a downstream ridge. Preferably, the liner body covers at least a portion of the annular support.

[0053] Preferably, the pad body covers at least a portion of the vibration generator.

[0054] Preferably, a pad covers and contacts the upper surface of the vibration generator, which is mounted to the top surface of the support.

[0055] Preferably, the housing includes a retainer that engages with the aerosol outlet portion of the housing, and the aerosol generator is supported by the retainer below the liquid supply chamber. Preferably, the retainer snaps into the aerosol outlet, and the engagement between the retainer and the aerosol outlet is assisted by the compression and axial reaction forces of upstream and downstream resilient seals.

[0056] Preferably, the retainer includes an annular seat for a downstream resilient seal, and wherein a support, orifice plate, vibration generator, and gasket are supported above the lower resilient seal. Preferably, the retainer forms an annular seat for the gasket.

[0057] Preferably, the retainer includes circumferentially and axially oriented tabs forming the sidewalls of the liner.

[0058] Preferably, the throat has a diameter of at least 18 mm in the plane of AP. 2 More preferably at least 20mm 2 More preferably at least 25mm 2 More preferably at least 30mm 2 The area.

[0059] In a preferred example, the throat has an area of ​​approximately 32 mm² in the plane of AP. 2 up to 40mm 2 Within the range.

[0060] Preferably, the area of ​​the throat in the plane of AP is at least twice the effective area of ​​the orifice plate.

[0061] Preferably, the gasket opening is in the housing and has a diameter of more than 5 mm when compressed, and more preferably more than 5.5 mm, and more preferably more than 6.0 mm.

[0062] Preferably, the liner opening has an axial dimension exceeding 2.0 mm. Preferably, the atomizer includes a pair of conductive spring pins for driving the vibration generator, and one or both of the pins extend through a hole in the liner.

[0063] Preferably, the liner is medical-grade liquid silicone rubber, provided as a two-component compound that is mixed together and injected into a hot mold for curing.

[0064] Preferably, the pad has a Shore hardness in the range of 20 to 80 Shore A, more preferably in the range of 30 to 60 Shore A.

[0065] In a preferred example, the liner includes multiple downstream ridges.

[0066] In a preferred example, the vibration generator is mounted to the upstream surface of the support, and at least one downstream extending ridge extends around the outer periphery of the vibration generator.

[0067] In a preferred example, the gasket extends radially to form a resilient seal between the plastic housing components.

[0068] In a preferred example, the pad extends radially to completely cover the vibration generator.

[0069] In a preferred example, the liner extends radially to completely cover the support.

[0070] In a preferred example, the liner extends radially to engage the housing at its outer edge.

[0071] In a preferred example, the liner has a surface roughness in the range of 1.6 μm to 3.2 μm on at least a portion of its exposed surface.

[0072] In a preferred example, the liner has a hydrophilic coating on at least a portion of its exposed surface.

[0073] We also describe a method of manufacturing an atomizer of any of the examples described, the method comprising: mounting an aerosol generator to a retainer and automatically moving the retainer toward the housing container until the retainer snaps into place on the housing, the snap-in engagement being held by axial elastic reaction forces of upstream and downstream seals. Attached Figure Description

[0074] The invention will become more clearly understood from the following description of some embodiments thereof, which are given by way of example only with reference to the accompanying drawings, wherein:

[0075] Figure 1 This is a 3D exploded view of the atomizer;

[0076] Figure 2 This is a cross-sectional view of the atomizer;

[0077] Figure 3 This is a three-dimensional view of the aerosol generator being removed from its housing;

[0078] Figure 4 shows a set of views of the top liner of the aerosol generator:

[0079] (a) A three-dimensional view,

[0080] (b) A cross-sectional view through the gasket, showing the hole for the conductive pin.

[0081] (c) Top view, and

[0082] (d) Bottom view;

[0083] Figure 5 This is a cross-sectional view before the conductive pins make contact during assembly; and

[0084] Figure 6 Is with Figure 5 A similar view, in this case: after the pin contacts the piezoelectric vibration generator (“piezoelectric body”) and the support pad, the retainer snaps into place;

[0085] Figure 7 The image shows bubbles forming on the perforated plate (especially around the edge where the edge is attached to the support pad by welding), and, Figure 8 These are a pair of magnified images showing the surfaces of two pads configured to minimize bubble trapping and expansion at the pad surfaces.

[0086] Figure 9 and Figure 10 It is an alternative atomizer equivalent to Figure 5 and Figure 6 A view in which the padding has downward-hanging edges;

[0087] Figures 11 to 14 It is another alternative atomizer equivalent to Figure 2 , 3 Views 5 and 6, in which the gasket has a body that extends further radially to surround the radially outer conductive pin;

[0088] Figure 15 This is a perspective view of an atomizer according to an alternative embodiment, wherein the aerosol generator is shown outside the housing, and Figure 16 It is a schematic cross-sectional view showing the aerosol generator being inserted to demonstrate the function of the ramp in the toe of the retainer;

[0089] Figure 17 It has Figure 15 A schematic cross-sectional view of an alternative atomizer with a wider top (upstream) liner, featuring the beveled characteristics of the atomizer.

[0090] Figure 18 This is a cross-sectional perspective view of an atomizer with a liner similar to the previous example, but in this case, electricity is conducted to the piezoelectric element via a spring clip instead of a pin; and

[0091] Figure 19 To show in more detail Figure 18 A cross-sectional perspective view of an aerosol generator. Detailed Implementation

[0092] We describe an orifice plate atomizer having a liquid vessel (preferably delivered directly by gravity) onto an orifice plate (having pores in the micrometer range), wherein the vessel or container is configured to provide a throat above the orifice plate (“AP”). The container is characterized by reduced bubble formation and consistent and predictable flow of liquid on the container side of the AP. One such feature is the throat size, which is too large to form noticeable bubbles. Preferably, the throat size has a diameter of at least 18 mm in the plane of the AP. 2 The area, more preferably at least 20 mm 2 More preferably at least 25mm 2 More preferably at least 30mm 2 The area. In one example, the throat area is approximately 34 mm². 2 And preferably at about 32mm 2 Up to 40mm 2 Within the range.

[0093] Preferably, the throat area is at least twice the effective area (active area) of the orifice plate (the vibrating portion of the AP, inside the attachment edge). In one example, the AP consists of a diameter of 3.50 mm and an area of ​​9.6 mm². 2 It is made of electroformed metal. In this case, the throat area is preferably at least 20 mm². 2 .

[0094] The aerosol generator can be of the type with a pad-shaped support, to which the annular piezoelectric vibration generator is attached upstream or downstream, and the perforated plate is connected to the inner edge of the support by, for example, welding. The attachment of the AP to the support pad can alternatively be done by adhesive, as described in our published patent specification WO2019 / 115221, the contents of which are incorporated herein by reference. Typically, the AP has an edge attached to the support, and an active portion, i.e., the vibrating part, inside the edge.

[0095] The orifice plate can have a main body (the vibratory, active portion) with orifices approximately 6 μm in diameter and a density of approximately 90 per millimeter in cross-section (the density could be much higher, such as thousands per millimeter as described in WO2012 / 092163, if fabrication uses a photodefined mask). An edge surrounds this body, with a lower surface for attachment to a support gasket. The AP is directly supported on the support gasket, laterally inside the resilient seal and vibration-driven piezoelectric element, without any mechanical clamping. Grooves can be present in the surface of the AP edge to facilitate adhesion. The AP edge can be micromachined in the lower surface to have multiple parallel anchoring grooves, each groove having a pair of side surfaces and a base surface substantially in the plane of the AP. The grooves are located in the lower surface, typically extending radially, and have a zigzag pattern when viewed in plane, with straight lengths between bends. In this example of adhesive attachment, a high density of grooves is generally preferred, consistent with maintaining sufficient mechanical strength in the orifice plate, particularly at the edges where the orifice plate is attached to the gasket. For example, there may be 72 grooves in one example, and preferably there are 30 to 130 grooves.

[0096] Typically, preferably, when adhesive attachment is used instead of welding, the provided anchoring grooves have a depth ranging from 10 μm to 40 μm, a width ranging from 20 μm to 150 μm, an angular pitch ranging from 2.5° to 12.5°, and they have at least one bend in the direction, with each bend having an angle ranging from 45° to 120°, and preferably from 80° to 105°. The adhesive is applied to the edges, on the underside, and between the edges and the gasket. In cross-section, the gasket is inclined with a convex curvature away from the plane of the orifice plate. Advantageously, the adhesive forms rounded corners at the bends of the gasket away from the lower surface of the orifice plate. This provides excellent mechanical strength by integrating the gasket into the orifice plate.

[0097] On the upstream side, a gasket is provided between the vessel shell and the aerosol generator at the AP support. This gasket has an edge extending between the support and the shell in an axial / longitudinal direction (parallel to the axis of the orifice plate), and a transverse portion extending radially to cover at least a portion of the support. This configuration causes the gasket to tend to deflect radially outward when axial pressure is applied during manufacturing, thereby forming a tapered ramp on the inner surface of the central opening of the gasket. This provides a funnel shape around at least a portion of the circumference of the throat. The shell configuration preferably provides an inner surface that forms a continuation of the inner surface of the gasket opening. This provides a throat funnel shape formed by the combination of the inner surface of the gasket opening and the inner surface of the shell container. This funnel shape can be provided by a top gasket that does not extend radially to a great extent, and in some examples, does not extend as far as the piezoelectric actuator. In one such example, it only extends radially to the extent that forms the inner edge of the gasket opening. The exposed surface of the gasket interior in contact with the liquid is preferably not overhanged by the shell and can be textured in a manner as described below to reduce the tendency for bubbles to form on the surface. Additionally or alternatively, a hydrophilic coating may be present on one or both of the exposed surfaces inside the liner and the container surface.

[0098] By having different components contact the liquid, gaskets, and housing, combinations of surface types can be readily provided to optimize liquid flow to the AP while minimizing bubble formation.

[0099] Preferably, the gasket, together with the aerosol generator, is supported and mounted on the retainer as an integral assembly, which engages as a unit with the rest of the housing. This action preferably involves movement toward the liquid supply chamber (container) until the retainer and gasket snap-fit ​​into place, wherein the gasket is axially compressed against the housing around the throat. The gasket is accurately and concentrically positioned within the annular seat of the retainer, and this is preferably provided by resilient tabs that are arcuate and spaced apart around the circumference of the gasket seat.

[0100] refer to Figure 1 The following are the main components of atomizer 1:

[0101] 2. The entire body is made of plastic.

[0102] 3. Liquid supply room (or "container")

[0103] 4. Aerosol delivery tube outlet,

[0104] 5. Aerosol generator assembly,

[0105] 6. Holder, which supports the aerosol generator 5 in the overall housing body 2;

[0106] 20. Tubular top of the container,

[0107] 21. The funnel-shaped lower part of the container (“funnel”),

[0108] 22. Liquid supply chamber cap;

[0109] 23. Cap-shaped tubular opening,

[0110] 24. Silicone cap,

[0111] 30. Conductive pin support portion of housing body 2;

[0112] 31, 32 are conductive pins that extend through the pin support housing portion 30;

[0113] The top 20 of the container is in fluid communication with the inclined funnel-shaped lower portion (“funnel”) 21 for delivering liquid onto the orifice plate (“AP”). An aerosol delivery tubular outlet 4 is located below the AP, integral with the container portion, and coaxial with the AP. The axis of the funnel 21 is inclined relative to the axis of the AP. This allows for atomization of the atomizer in a wide range of directions, relying on the gravity falling of the liquid onto the AP.

[0114] Conductive pins 31 and 32 are used to conduct electricity to the piezoelectric vibration generator of the aerosol generator and are held and guided within the pin receiving part 30 of the housing body 2.

[0115] The retainer 6, used to support the aerosol generator assembly 5, is pressed against the lower surface of the funnel 21. The aerosol generator assembly 5, from top to bottom, includes: an upstream seal, i.e., a gasket 48; a piezoelectric vibrator (“piezoelectric”) 46; an adhesive ring 47 below the piezoelectric 46; an orifice plate 41; a welded ring 42; an annular gasket-shaped aerosol generator support (“gasket”) 40; and a downstream O-ring 43. This assembly is supported by the retainer 6 and surrounded by the aerosol delivery tube 4. The piezoelectric adhesive ring 47, although shown as a separate component for illustrative purposes, is actually adhesively bonded between the piezoelectric 46 and the gasket 40, attaching the piezoelectric to the gasket in a manner that conducts electricity to the underside of the piezoelectric 46. Similarly, the welded ring 42 is part of the edge of the orifice plate (“AP”) 41 and the inner edge of the gasket 40, attaching the AP to the gasket. In other examples, the attachment of the AP may be adhesive rather than welded. This example relates to an electroformed perforated plate 41 with "hourglass" shaped holes. However, in other examples, the perforated plate can be formed using photo-defined technology as described in our prior patent specifications no. WO2012 / 092163 or no. WO2013 / 186031. A reservoir of liquid supply chambers may be present above the aerosol forming holes, formed, for example, in a manner described in WO2012 / 092163 or WO2013 / 186031, and these holes may have diameters ranging from 20 μm to 400 μm.

[0116] The orifice plate 41 has an outlet opening diameter in the range of 1 μm to 10 μm, and in one example it is about 2 μm to 3 μm.

[0117] Also refer to Figure 2 and 3 The retainer 6 is configured to securely support and accommodate components of the aerosol generator assembly 5. It has a circumferential wall 60 with a top edge 61 and a pair of lower overhanging legs 62 with toes that engage as clips into corresponding recesses 67 in the aerosol outlet tube 4. At its upper end, a series of circumferentially extending elongated tabs 65 define the outer surface of the circular seat for the pad 48, and... Figure 3 The pad 48 is shown being held in a concentric position within the tab 65.

[0118] The retainer 60 also forms an annular seat 68 for the downstream O-ring 43. Figure 5 and 6 As shown most clearly in the image, the gasket 40 is supported below by an O-ring 43 housed within a groove 68 of the retainer 6. The gasket 40 rests against the O-ring 43 and is itself supported by the piezoelectric element 46 adhered to the top surface of the gasket 40. The AP 41 is attached to the gasket 40 via a welding ring 42.

[0119] The liquid supply container funnel 21 has an inner conical surface 26 that slopes inward toward AP 41, defining a throat 8 above AP together with the inner surface 72 of the liner. The latter is not overhanged by the shell, forming a continuation of the shell surface. By making the two parts, the liner and the shell, form a container shape leading to the orifice plate, a combination of multiple surface types is provided to optimize liquid flow to AP while minimizing bubble formation, which is convenient and versatile.

[0120] The shell 21 forms a continuation of the inner surface 72 of the liner 48, such that together they provide a liquid flow funnel toward the AP. As described in more detail below, this not only allows for smooth and streamlined flow, but also allows for the provision of different surfaces near the AP, for example, by means of the desired roughness of the liner surface 72, to optimize flow characteristics and / or, and bubble prevention. The container 3 is inclined away from the axis of the AP and forms a greater angle with the AP axis on its underside. On the underside, for at least a portion of the circumference of the throat, the funnel wall 26 diverges at an angle relative to the axial direction away from the throat region, preferably greater than 45°, more preferably greater than 50°, and even more preferably greater than 55°. In this particular example, this angle is at its maximum of approximately 60°. This provides the maximum amount of space on the AP, thereby minimizing the surface area for bubble growth, as described in more detail below.

[0121] The compressed axial (longitudinal axis of the orifice plate center) distance between the plane of the orifice plate edge and the bend at its unfolded position within the housing is 2.3 mm, and more generally preferably in the range of 1.8 mm to 3.0 mm. This provides a sufficiently short distance from the AP unfolding to help minimize bubble prevention. The fact that the inner surface of the gasket provides this dimension of approximately 1.8 mm is helpful because it can have the required surface roughness to further prevent bubble formation. Generally, the axial dimension of the gasket at the throat is preferably in the range of 1.5 mm to 3.0 mm.

[0122] The top (upstream) gasket 48 is sandwiched between and compressed by the bottom surface of the gasket 40 and the housing body funnel 21. The gasket 48 counteracts the forces from the O-ring 43 and from the pins 31 and 32.

[0123] Specifically, as shown in Figure 4, the gasket 48 comprises a body 70 of molded material to form a downstream overhanging circular edge 71 with an inner surface 72 forming an opening that is part of the throat 8 for supplying liquid to the AP. The edge 71 provides a gasket depth greater than the depth of the rest of the body 70 and extends downstream of the opening surface 72 as it forms part of it. In this example, the depth of the edge 71 below the body 70 is 0.8 mm, and is generally preferably in the range of 0.5 mm to 1.1 mm. The body extends in a radial (lateral) direction to provide a generally contoured annular gasket shape, and thus it engages between multiple components, such as between the piezoelectric element 46 and the container 21, and between the support 40 and the housing 21. Therefore, it provides a seal and balance within the aerosol generating core.

[0124] The gasket body 70 is also the integral base for the internal and external concentric circular top ridges 74 and 75, which extend in the upstream direction to contact the housing container. They have a height of 0.3 mm and are generally preferred to have a height in the range of 0.1 mm to 0.5 mm. The body 70 has a through-hole 76 for receiving a radially inner conductive pin 32. The outer edge of the body 70 also has a notch 78 to prevent incorrect assembly. If the retainer is not in the correct circumferential orientation, it prevents the seal from being loaded into the retainer.

[0125] Gasket 48 is a medical-grade liquid silicone rubber, provided as a two-component compound, which is mixed together and injected into a hot mold for curing. Typically, the preferred gasket has a Shore A hardness in the range of 20-80 Shore A, more preferably in the range of 30-60 Shore A.

[0126] In this case, the dimensions of pad 48 during relaxation are:

[0127] Inner diameter, 6.2mm;

[0128] Outer diameter, 14.7 mm;

[0129] Maximum depth: 2.1mm;

[0130] The height of ridges 74 and 75 is 0.3 mm.

[0131] The height of ridge 71 relative to body 70 is 0.6 mm.

[0132] In this example, the throat 8 has a diameter of approximately 6.0 mm and is defined by the opening 72 of the liner 48 at its lower end closest to the AP. This large-diameter throat reduces the risk of air bubble trapping due to air intake.

[0133] From the perspective of sealing and protecting the piezoelectric element 46 and the electrical connection, the gasket 48 allows for dimensional variations in the plastic housing components.

[0134] like Figure 3 As shown, the liner 48 is positioned on the retainer 6 during automated assembly. This allows for precise placement and automated manufacturing, which is particularly important for the accurate positioning of the liner relative to the aerosol generator 5 components.

[0135] Refer again Figure 5 and 6 The image shows the positions of the retainer 6 before and after it is fully inserted, with the retainer 6 and aerosol generator 5 configured as sub-assemblies and pushed upward against the lower surface of the funnel 21. From Figure 6 It can be clearly seen that in the final position, leg 62 snaps into the groove 67 of the aerosol outlet tube 5, where the downstream O-ring 43 and gasket 48 are slightly compressed axially. Therefore, the manufacturing process can be efficient and tolerate small placement variations. The components of the aerosol generator 5 are axially loaded ( Figure 1 (The alignment used for manufacturing is best shown in the diagram), and then they are pressed axially upward against the lower surface of the housing wall 21, which is simple. This is a reliable method for sealing and positioning. Figure 5 and 6 A divergent surface 69 downstream of the throat 8 is also shown for aerosol flow from the AP.

[0136] The throat diameter of approximately 6.2 mm is achieved through the opening diameter of the gasket 48 (72). For example... Figure 6 As shown, due to axial compression, the opening is tapered, providing a funnel shape. When the gasket loosens, this diameter narrows and may be 0.1 mm to 0.3 mm smaller than the nominal 6.2 mm diameter at the downstream end.

[0137] The cone shape of the opening is facilitated by the downward-protruding edge 71, which is much more deformable than the body 70.

[0138] Advantages of physical support and sealing for aerosol generator 5

[0139] The aerosol generator 5 is in a vertically compressed state over a large area, providing a superior seal that is more tolerant of dimensional changes in the plastic housing components.

[0140] like Figure 6 As shown, the upper ridges 74 and 75 compress with axial compression, thereby providing grip and robust stability in a high-frequency environment where the plate may vibrate, for example, at 128 kHz.

[0141] In addition, the pad 48 covers the piezoelectric element 46, thereby limiting the possibility of moisture entering the conductive parts 31, 32, 46 and 40 from the funnel 21 in the throat region 8.

[0142] Refer again Figure 6 As can be clearly seen from the figure, the gasket 48 provides a high degree of balance to the forces generated by the conductive pins 31 and 32 pressing against the piezoelectric body 46 and the pad 40. This helps to ensure that most of the body 70 and its large surface area adjoin the underside of the funnel 21. Furthermore, the gasket 48 acts as a cover on the piezoelectric body 46, thereby helping to protect it from moisture intrusion in high humidity and high-frequency environments.

[0143] The pair of upper ridges 74 and 75 are particularly beneficial because they ensure uniform contact with the funnel 21 around the entire periphery of the liner, but not so high that they would prevent contact by the rest of the upper surface of the liner during axial compression.

[0144] bubble prevention

[0145] In this example, pad 48 has a finely textured surface finish with an arithmetic mean roughness Ra ranging from 1.6 μm to 3.2 μm. The roughness averaging parameter Ra is defined in 4.2.1 of ISO 4287:1998+A1:2009. Ra is calculated by measuring the average length between peaks and valleys within the sampling length, as well as the deviation from the average line across the entire surface. Ra is averaged over all peaks and valleys of the roughness profile, and outliers are then neutralized so that they have no significant impact on the final result.

[0146] The Ra range of 1.6 μm to 3.2 μm corresponds to 24 to 30 on the VDI 3400 (Charmilles) surface roughness grade (“VDI”).

[0147] refer to Figure 8The surfaces of the two pads are shown magnified 1000 times. The average surface finish roughness of the left pad is approximately 1.8 μm, while the average surface finish roughness of the pad on the right side is approximately 2 μm to approximately 3 μm. The surface roughness is more noticeable on the surfaces facing the camera because they are in focus. The roughness of the left pad may be more accurate because it is molded, and the surface roughness of the mold steel is precisely known.

[0148] Such surface roughness helps prevent small air bubbles from adhering to the inner liner surface over extended periods, and thus helps prevent bubble aggregation. Preferably, the roughness level corresponds to the level of bubbles that tend to aggregate and merge above the edges of the AP (orifice size of 2 μm to 6 μm and vibration frequency of approximately 128 kHz). Surface roughness Ra values ​​of 1.6 μm to 3.2 μm are particularly effective for orifice diameters in the range of approximately 1 μm to 6 μm and / or vibration frequencies in the range of approximately 60 kHz to 200 kHz, more preferably in the range of 100 kHz to 160 kHz.

[0149] Figure 7 The diagram shows naturally formed bubbles on the upper surface of the AP, particularly around its edges, caused by air being drawn in through the holes due to the AP vibrating at a frequency of 128 kHz. We have found that surface roughness values ​​of Ra in the range of approximately 1.6 μm to 3.2 μm are better than those of smoother surfaces. Bubbles rising from the AP are less likely to stagnate on the surface of the pad.

[0150] The desired surface roughness can be achieved in any desired manner. Figure 8 The image on the left is a pad formed by injection molding, while the image on the right is formed by 3D printing.

[0151] The pads can be molded, for example, from thermoplastic elastomer materials (such as those grades provided by BASF), or manufactured by additive manufacturing technology (3D printing) as described above.

[0152] It has excellent liquid flow to AP due to the container having a smooth internal funnel surface, which results in softer materials with higher surface roughness.

[0153] In other embodiments, the liner and / or funnel are coated with a hydrophilic coating to further reduce the risk of bubble stagnation and coalescence. The hydrophilic coating is thin enough not to affect surface roughness but to prevent bubble coalescence. The hydrophilic coating preferably has a thickness in the range of 0.5 μm to 2.0 μm.

[0154] In various examples, the hydrophilic coating may be a monomeric component containing vinyl acetate, hexamethyldisiloxane (HMDSO) mixed with oxygen in a given ratio, wherein HMDSO is more abundant than O2.

[0155] Alternative padding configuration

[0156] refer to Figure 9 and 10 The atomizer 200 has a liner 201 instead of a liner 48, and all other components are identical and designated by the same reference numerals. The liner 201 has a downwardly drooping edge 202 around its outer edge, located radially between the two pins 31 and 32. This facilitates increased enveloping of both the liner and the funnel 21 around the piezoelectric element and the degree of contact with the vibrating surface. The enveloping effect on the radial sides and top of the piezoelectric element helps ensure reliability, even if slight moisture leakage occurs into the space above the liner due to the gap between the retainer and the housing.

[0157] refer to Figures 11 to 14 An alternative atomizer 300 has a liner 301 replacing the liner 48, and other components are identical and indicated by the same reference numerals. The liner 301 has a further radially extending body 302 and, in addition to the hole 304 for the pin 32, a hole 303 for the radially outward pin 31. It has upstream ridges 305 and 306, which are similar to ridges 74 and 75 of the liner 48. The liner body 302 extends radially far enough to engage the housing 5 at its outer peripheral edge. The liner 301 has an opening surface 307 formed in part of the throat above the AP, as... Figure 12 and 14 The best result is shown in the middle.

[0158] The advantage of this arrangement is that it provides a larger surface contact area at the top. Furthermore, it provides a resilient seal between the two mating plastic components (retainer and container / shell).

[0159] Alternative retainer

[0160] refer to Figure 15 and 16An alternative atomizer 400 has a housing 401 with an aerosol outlet channel 410 having a pair of opposing recesses 411 with a lower edge 412. A retainer 402 has a tubular body 403 with a pair of opposing legs 404, each leg 404 having toes for snapping into the opposing recesses 411, as in other embodiments. However, in this case, each leg 404 additionally has a radially outward bevel 405, which facilitates insertion of the retainer 402 during manufacturing. This reduces impact when the body is placed downwards onto the retainer during assembly.

[0161] Figure 17 A retainer 500 with a main body 502 is shown, the main body 502 having opposing legs 504, the legs having toes with bevels 505. These snaps engage in a notch 511 with a lower edge 512. In this case, the liner is a liner 201 that extends radially across the piezoelectric body and into the housing, engaging with the support on the radially outer side of the piezoelectric body.

[0162] The method of supplying power to the piezoelectric element may differ from the illustration, and there are no pins connecting the piezoelectric element and the support. For example, as shown... Figure 18 and 19 As shown, the atomizer has a top housing 665 providing a funnel and a lower aerosol outlet portion 660 supporting the aerosol generator assembly 600. In this case, a top liner 601 is provided, which forms a portion of the throat above the AP and extends radially above a portion of the support pad 610. An annular piezoelectric element 620 is adhered to the underside (downstream) side of the support 610 by a conductive adhesive, thus removing the component from above the support and leaving more space for a wider throat area. The pad 610 is supported below by an O-ring 630 in a manner generally similar to that of other embodiments. However, in this case, power is supplied by an annular spring clip assembly 650, which has an annular body supporting a C-shaped clip that extends radially outward and back inward to engage the underside of the pad 610. A clip 652, in the general form of a leaf spring, is also provided, which engages the underside of the piezoelectric element 620. Therefore, the power to the top surface of the piezoelectric element 620 is provided by the spring clip terminal 651 via the pad 610, and the power directly to the bottom surface of the piezoelectric element is provided by the spring terminal 652.

[0163] It should be understood that the present invention provides an atomizer with numerous significant improvements resulting from an upstream resilient seal. This seal, which forms part of the throat in the container and also functions as a seal, is a single component performing two very important functions. Particularly advantageous is that the housing has no overhang on the exposed surface of the upstream resilient seal, providing a streamlined method for liquid delivery to the orifice plate. Furthermore, the exposed surface of the seal can be modified to provide enhanced bubble prevention benefits, such as a roughened surface. This is particularly advantageous in examples where the exposed surface of the seal is funnel-shaped. Another key advantage is that the arrangement of the housing and the upstream seal allows for a relatively wide throat, thereby contributing to predictable and efficient liquid flow to the orifice plate.

[0164] This invention is not limited to the described embodiments, but can be modified in structure and details. For example, the area of ​​the throat region may be greater than 34 mm. 2 It is conceivable that, in other examples, the gasket may have a downwardly overhanging edge similar to gasket 201 and a top surface area and radial extent similar to gasket 301. The downstream resilient seal may not be in the form of an O-ring. It may be a ridge of resilient material extending from the housing, and it may be secured to the housing. It may have some characteristics of the gasket, such as a body that can extend radially outward beyond the extent of the O-ring shown. It is also conceivable that, in other examples, the downstream extending edge of the top gasket may not necessarily be at the gasket opening, but rather extend radially outward from it by a small portion.

[0165] In addition, such as in Figure 18 and 19 As shown, power can be provided by contacts other than conductive pins. The electrical conductor may include at least one first spring contact engaging with a support or vibration generator, and a second spring contact engaging with another of the vibration generator or support, the first and second spring contacts providing opposing electrical contacts for supplying power to the vibration generator. The support may extend radially beyond the vibration generator, and the first spring contact engages the support surface laterally to the vibration generator. The second spring contact may directly contact the vibration generator. At least one of the spring contacts may be in the form of an arcuate resilient ridge in axial (longitudinal) view, and terminal 652 is an example. The resilient ridge may extend at least partially around an orifice plate. The resilient ridge may extend upstream from the contact assembly base, and the base may also support spring contacts that extend radially outward and bend radially inward to engage the support or vibration generator surface. Bending can provide elasticity to the spring contacts. Spring contacts with bending can engage the support radially outward from the vibration generator.

[0166] Spring contacts can be mounted onto a contact assembly that is mounted onto the housing on the upstream or downstream side, but are preferably mounted downstream because this provides more space for a wide throat area.

[0167] It is also conceivable that the liner may have only a very limited radially extended body, but provides excellent advantages through the elastic upstream support and the roughness of the surface in contact with the liquid at the location where it forms part of the funnel throat. In one example, the liner body extends only to approximately the radial extent of ridge 74. Generally, any feature of the atomizer described herein can be used in different combinations with other features not described herein. Furthermore, it is conceivable that the housing may be provided by more or fewer interconnected components. For example, the aerosol outlet may be a separate component mounted to the container or to an intermediate housing component. Ultrasonic welding may be used, for example, to join the components together.

Claims

1. An atomizer, comprising: Shell (2, 6) Liquid supply container (3) formed by the shell. The aerosol outlet (4) formed by the shell. Aerosol generator (5), which is installed in the housing and includes: Vibrating perforated plate (41). An annular support member supporting the perforated plate. Vibration generator (46) attached to the annular support. Electrical conductors used to transmit power to the vibration generator A downstream resilient seal (43), which is mounted on the side of the orifice plate opposite to the liquid supply container between the housing and the annular support, and An upstream resilient seal (48) is mounted between the annular support (40) and the housing container (21) and has an opening (72) formed on a portion of a throat (8) above the orifice plate (41), wherein at least a portion of the exposed surface of the opening of the upstream resilient seal is roughened and has an average surface roughness in the range of 1.6µm to 3.2µm.

2. The atomizer according to claim 1, characterized in that, The upstream resilient seal includes a gasket having a body (70) and a downstream extending edge (71) near the opening (72), the body (70) extending radially from the edge (71) in an annular shape.

3. The atomizer according to claim 2, characterized in that, The liner includes at least one upward-pointing ridge (74, 75) for engaging with the surface of the housing (21).

4. The atomizer according to claim 3, characterized in that, It has two or more upward-pointing ridges (74, 75).

5. The atomizer according to claim 3 or 4, characterized in that, At least one of the ridges (74, 75) is circular in the plane.

6. The atomizer according to claim 5, characterized in that, The ridges (74, 75) are concentric circles in the plane.

7. The atomizer according to claim 5, characterized in that, The ridges (74, 75) have a height in the range of 0.1 mm and 0.5 mm, and the downstream extending edge has a depth relative to the pad body (70) in the range of 0.5 mm and 1.1 mm.

8. The atomizer according to any one of claims 1 to 4, characterized in that, The upstream resilient seal is configured such that, under axial compression, the opening (72) has an inner surface that tapers inward in the flow direction to form a funnel shape at the throat.

9. The atomizer according to any one of claims 1 to 4, characterized in that, The inner surface of the opening (72) of the upstream resilient seal forms a downstream continuation of the inner surface of the housing container when the seal is in a compressed state.

10. The atomizer according to any one of claims 2 to 4, characterized in that, The pad body (70) covers at least a portion of the annular support (40).

11. The atomizer according to any one of claims 2 to 4, characterized in that, The pad body (70) covers at least a portion of the vibration generator (46).

12. The atomizer according to claim 11, characterized in that, The pad covers and contacts the upper surface of the vibration generator (46), which is mounted on the top surface of the support (40).

13. The atomizer according to any one of claims 1 to 4, characterized in that, The housing includes a retainer (6) that can engage with the aerosol outlet, and the aerosol generator (5) is supported by the retainer (6).

14. The atomizer according to claim 13, characterized in that, The retainer (6) engages with the aerosol outlet within the recess (67) of the housing via the toe (62) of the retainer, and the engagement is aided by the compression and axial reaction forces of the downstream resilient seal (43) and the upstream resilient seal (48), with the retainer (6) snap-fitting into the aerosol outlet.

15. The atomizer according to claim 14, characterized in that, The retainer includes an annular seat (68) for a downstream resilient seal (43), wherein the support (40), the orifice plate (41), the vibration generator (46) and the gasket are supported above the downstream resilient seal.

16. The atomizer according to claim 13, characterized in that, The retainer (6) forms an annular seat for the liner.

17. The atomizer according to claim 16, characterized in that, The retainer includes circumferentially and axially oriented tabs (65) forming the sidewalls of the annular seat.

18. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has a depth of at least 18 mm in the plane of the orifice plate. 2 The area.

19. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has a depth of at least 20 mm in the plane of the orifice plate. 2 The area.

20. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has a depth of at least 25 mm in the plane of the orifice plate. 2 The area.

21. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has a depth of at least 30 mm in the plane of the orifice plate. 2 The area.

22. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has a diameter of 32 mm in the plane of the orifice plate. 2 Up to 40mm 2 The area within the specified range.

23. The atomizer according to any one of claims 1 to 4, characterized in that, The throat (8) has an area in the plane of the orifice plate that is at least twice the vibratory area of ​​the orifice plate (41).

24. The atomizer according to any one of claims 1 to 4, characterized in that, The opening (72) of the upstream resilient seal has a diameter exceeding 5 mm when it is in the housing and compressed.

25. The atomizer according to claim 24, characterized in that, The opening (72) of the upstream resilient seal has a diameter exceeding 5.5 mm when it is in the housing and compressed.

26. The atomizer according to claim 25, characterized in that, The opening (72) of the upstream resilient seal has a diameter exceeding 6.0 mm when it is in the housing and compressed.

27. The atomizer according to any one of claims 1 to 4, characterized in that, The opening (72) of the upstream elastic seal has an axial dimension in the range of 1.8 mm and 3.0 mm.

28. The atomizer according to any one of claims 1 to 4, characterized in that, The opening (72) of the upstream resilient seal has an axial dimension exceeding 2.0 mm.

29. The atomizer according to any one of claims 2 to 4, characterized in that, The atomizer includes a pair of conductive spring pins (31, 32) for driving the vibration generator, and one or both of the pins extend through a hole (76) in the liner.

30. The atomizer according to any one of claims 1 to 4, characterized in that, The upstream elastic seal (48) is a medical-grade liquid silicone rubber provided as a two-component composite that is mixed together and injected into a hot mold for curing.

31. The atomizer according to any one of claims 1 to 4, characterized in that, The upstream resilient seal has a Shore hardness in the range of 20 to 80 Shore A.

32. The atomizer according to any one of claims 1 to 4, characterized in that, The upstream resilient seal has a Shore hardness in the range of 30 to 60 Shore A.

33. The atomizer according to any one of claims 2 to 4, characterized in that, The liner includes multiple downstream ridges (71, 202).

34. The atomizer according to claim 33, characterized in that, The vibration generator is mounted to the upstream surface of the support (40), and at least one downstream extending ridge (202) extends around the outer periphery of the vibration generator (46).

35. The atomizer according to any one of claims 2 to 4, characterized in that, The gasket extends radially to form a resilient seal between the plastic housing components (21, 4).

36. The atomizer according to any one of claims 2 to 4, characterized in that, The pad extends radially to completely cover the vibration generator (46).

37. The atomizer according to any one of claims 2 to 4, characterized in that, The pad extends radially to completely cover the support (40).

38. The atomizer according to any one of claims 2 to 4, characterized in that, The gasket extends radially to engage the housing at its outer edge (302).

39. The atomizer according to any one of claims 1 to 4, characterized in that, The upstream resilient seal has a hydrophilic coating on at least a portion of its exposed surface.

40. The atomizer according to claim 13, characterized in that, The retainer includes at least two opposing bevels (405, 505) for guiding the retainer into the housing.

41. The atomizer according to any one of claims 1 to 3, characterized in that, The shell container is curved to widen from the throat, and the curve extends at an angle of more than 40° relative to the axial direction.

42. The atomizer according to any one of claims 1 to 3, characterized in that, The perforated plate has holes with diameters ranging from 2µm to 6µm.

43. The atomizer according to claim 42, characterized in that, The axial distance between the plane and the edge of the orifice plate and the bend is in the range of 1.8 mm and 3.0 mm.

44. The atomizer according to any one of claims 1 to 3, characterized in that, The axial dimension of the seal at the throat is in the range of 1.5 mm and 3.0 mm.

45. A method of manufacturing an atomizer according to any one of claims 13 to 36, the method comprising: The aerosol generator (5) is installed onto the retainer (6), and the retainer is automatically moved toward the housing container (221, 8) until the retainer is snapped into place on the housing (62, 67) and held in place by the axial elastic reaction force of the upstream elastic seal (48) and the downstream elastic seal (43).

46. ​​The method according to claim 45, characterized in that, The retainer includes at least two opposing bevels (405, 505) for guiding the retainer into the housing, and the movement of the retainer toward the housing container is guided and aligned by the bevels.

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