OSCILLATING CONSTRUCTION FOR AN ULTRASONIC ATOMIZING INHALER

Abstract: This oscillating construction for an ultrasonic atomizing inhaler includes an oscillation element which is excited to vibrate ultrasonically, and this oscillation element has two adjoining regions which have substantially different vibra- tional characteristics. Liquid supply is made to one of the regions, and the oscillation for atomization takes place in the other region, according to the particular frequency of ultrasonic excitation of the oscillation element which is appropriately chosen. The region to which liquid is supplied has a resonance frequency which is different from that of the region for atomization, and substantially no atomization takes place in the liquid supply region. Therefore, even when the load imposed on the oscillation element by liquid, thereon changes, as for example if the amount of the liquid thereon has changed, oscillation of a constant frequency continues in the atomization region, and thereby proper atomization is maintained. Thus, there is provided an ultrasonic atomizer which affects proper supply of liquid to be atomized, which does not cause oversupply or under­ supply of liquid to be atomized, and which further can handle fluids of various different viscosities. including even quite viscous liquid, and is not wasteful of atomization liquid. Thus, this ultrasonic atomizer is not uneconomical during use. Further, it is not prone to dribbling of atomization liquid, and thus is not liable to cause a mess.

Description: The present invention relates to the field of ultrasonic atomizing inhalers, and in particular to an improved oscillating construction for such an ultrasonic atomizing inhaler which improves on the prior art. There are various types of ultrasonic atomizing inhalers; one of these typically has a horn construction for vibrating at an ultrasonic frequency and for atomizing liquid supplied thereto, and the atomized liquid drifts away from said horn construction and enters into the mouth and/or the nose of a user. Such an ultrasonic atomizing inhaler is typically used for the inhalation of liquid medicine, and for humidification of the larynx of the user. The horn construction of a typical such ultrasonic atomizing inhaler is shown in Fig. 1a of the accompanying drawings in side view, and in Fig. 1b in an end on view. In this inhaler, the cone shaped horn construction e serves for concentrating ultrasound waves produced at its larger end a by the vibration of an ultrasonic oscillating element c which is driven by an oscillation circuit g, into its smaller end b, so as to vibrate an oscillating plate d integrally formed at its said smaller end b. A supply of liquid such as medicine is held in a storage bottle (not shown), and is picked up therefrom by a wick construction or absorptive bar f and is delivered little by little to the oscillating plate d by capillary action, whence it is atomized into the air by the vibrations of said oscillating plate d, to drift into the mouth and the throat and lungs of a user. And the horn construction b is held in place by a flange h which is connected to a main body (not shown) of the inhaler. In such a conventional ultrasonic atomizing inhaler, the oscillation member such as the plate d is typically a circular plate or disk, and proper atomization is possible only when the oscillation frequency produced by the oscillation circuit g and the resonance frequency of the oscillation plate d are well matched, so that said plate d becomes excited. But, when the supply of liquid from the absorptive bar f or the load condition has changed, as for example when a more viscous liquid is being used for atomization than before, the resonance frequency of the oscillation plate d with the load of liquid thereon accordingly changes, whereby the atomization action is weakened. Also, by droplets which have not been atomized adhering to the atomization surface of the oscillation plate d and thereby causing overload, the power consumption for driving the oscillation circuit g can become increased, and the durability of the battery is thereby undesirably reduced. When the quantitative control of the liquid supply is not proper, droplets tend to build up on the atomization surface of the oscillation plate d, thereby causing over supply of liquid, and because the liquid is not properly atomized by the power of the device the droplets have to be removed by hand, which is a great inconvenience and is also wasteful of possibly expensive liquid such as costly medication. Also, in the worst case, these accumulated droplets could dribble down out of the atomizer, which would be very messy. Therefore, in order to accomplish proper atomization, it is necessary to properly control the liquid supply, but since the liquid supply unit (not shown) is often removed away from the atomization plate d of the horn e for supply and replenishing of liquid, the engagement between the liquid supply unit and the atomization plate d of the horn e tends to change every time they are put together, whereby it has been difficult to satisfy the above mentioned conditions. Accordingly, unsatisfactory atomization action has sometimes occurred with the prior art. Another problem that has tended to occur with ultrasonic atomizing inhalers of this sort has related to particle size. The optimum particle size for inhalation of medication into the larynx varies according to the type of the medication and according to the exact point in the respiratory tract to which the medication is to be applied and to the symptoms of the patient, and in particular application of medication to the deep part of the trachea requires quite a different particle size for the atomized medication from that required by application to the shallow part of the larynx. Accordingly, it is desirable for an ultrasonic atomizing inhaler to be able to operate to atomize medication into particles of differing particle size. However, since the oscillation plate of the horn of a conventional ultrasonic atomizer is circular, it can have only one basic resonance frequency, and accordingly only can satisfactorily perform atomization at one frequency and at one particle size, with respect to a particular type of medication. Therefore, in order to change the average particle size of the atomized particles, it is necessary to prepare a plurality of ultrasonic atomizers (or, at least, horn assemblies) having different resonance frequencies. From FR-A-2 507 087 there is known an oscillating construction for an ultrasonic atomizing inhaler according to the preamble of claim 1, in which the oscillation element has uniform vibrational characteristics. The oscillation element can be excited to oscillate at either of two different frequencies. It is the primary object of the present invention to provide an oscillating construction for an ultrasonic atomizing inhaler which overcomes the above outlined problems. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which always effects proper atomization of the liquid supplied, even when the load on said oscillating construction changes. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which does not cause over supply or under supply of liquid to be atomized, and which can satisfactorily supply even viscous liquid. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which is not prone to accumulation of non atomized droplets of atomization liquid. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which is not wasteful of atomization liquid, or uneconomical during use. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which is not prone to dribbling of atomization liquid, or to being messy. It is a further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which can be easily replenished without any difficulties of adjustment. It is a yet further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler which can easily atomize liquid into mist of varying particle sizes, according to requirements. It is a yet further object of the present invention to provide such an oscillating construction for an ultrasonic atomizing inhaler with particle size variation capability, without requiring any proliferation of parts. According to the most general aspect of the present invention, these and other objects are accomplished by an oscillating construction for an ultrasonic atomizing inhaler, comprising an oscillation element which is excited to vibrate ultrasonically, characterised in that said oscillation element comprises two adjoining regions which have substantially different vibrational characteristics. According to such a structure, liquid supply is made to one of the regions having substantially different vibrational characteristics, and the oscillation for atomization takes place in the other region, according to the particular frequency of ultrasonic excitation of the oscillation element which is appropriately chosen. The region to which liquid is supplied has a resonance frequency which is different from that of the region for atomization, and substantially no atomization takes place in the liquid supply region. Therefore, even when the load imposed on the oscillation element by liquid thereon has changed, as for example if the amount of the liquid on the liquid supply region thereof has changed, the oscillation of a constant frequency continues in the atomization region, and thereby proper atomization is maintained. Thereby, there is provided an ultrasonic atomizer which effects proper supply of liquid to be atomized, which does not cause oversupply or undersupply of liquid to be atomized, and which further can handle fluids of various different viscosities, including even quite viscous liquid, and is not wasteful of atomization liquid. Thus, this ultrasonic atomizer is not uneconomical during use. Further, it is not prone to dribbling of atomization liquid, and thus is not liable to cause a mess. Further, according to a more particular aspect of the present invention, these and other objects are more particularly and concretely accomplished by an oscillating construction for an ultrasonic atomizing inhaler as described above, further comprising a means for exciting said oscillation element so as to cause it to vibrate ultrasonically, selectable to either of two different frequencies. According to such a structure, when the oscillation means is selected to oscillate at one of the frequencies and the ultrasonic oscillation element is driven by it, one of the two regions corresponding to this frequency alone oscillates, so that atomization is performed by this region, but when the oscillation means is selected to oscillate at the other frequency, then accordingly the other region of the ultrasonic oscillation element oscillates, and this region performs the atomization action. Since the two regions of the oscillation element have different oscillation frequencies, the two regions can perform atomization to produce different particle diameters. The present invention will now be shown and described with reference to the preferred embodiments thereof, and with reference to the illustrative drawings. It should be clearly understood, however, that the description of the embodiments, and the drawings, are all of them given purely for the purposes of explanation and exemplification only, and are none of them intended to be limitative of the scope of the present invention in any way, since the scope of the present invention is to be defined solely by the legitimate and proper scope of the appended claims. In the drawings, like parts and spaces and so on are denoted by like reference symbols in the various figures thereof; in the description, spatial terms are to be everywhere understood in terms of the relevant figure; and: Fig. 1a is a side view of an essential portion of a conventional ultrasonic inhaler, and Fig. 1b is an end on view thereof; Fig. 2 is a sectional view relating to an ultrasonic atomizing inhaler incorporating the first preferred embodiment of the present invention, showing a bottle thereof, a nozzle thereof as fitted into said bottle, and a horn unit thereof properly positioned with respect to said bottle, thereto, as seen from the side; Fig. 3 shows these parts as fitted to the top wall portion of the main body casing of the ultrasonic inhaler; Fig. 4 is a longitudinal sectional view of said ultrasonic atomizing inhaler incorporating the first preferred embodiment of the present invention as a whole, taken in the same sectional plane as Fig. 2; Fig. 5a is a side view, similar to Fig. 1a, of an essential portion of an ultrasonic inhaler incorporating the second preferred embodiment of the present invention, and Fig. 5b is an end on view thereof, similar to Fig. 1b; Fig. 6a is a side view, similar to Figs. 1a and 5a, of an essential portion of an ultrasonic inhaler incorporating the third preferred embodiment of the present invention, and Fig. 6b is an end on view thereof, similar to Figs. 1b and 5b; Fig. 7a is a side view, similar to Figs. 1a, 5a, and 6a, of an essential portion of an ultrasonic inhaler incorporating the fourth preferred embodiment of the present invention, and Fig. 7b is an end on view thereof, similar to Figs. 1b, 5b, and 6b; Fig. 8 is a circuit diagram for a drive circuit for driving an oscillation element, in a fifth preferred embodiment of the present invention; and Fig. 9a is an end on view, similar to Fig. 1b and so on, of an essential portion of an ultrasonic inhaler incorporating a sixth preferred embodiment of the present invention, and Fig. 9b is a side view thereof, similar to Fig. 1a and so on; The present invention will now be described with reference to the preferred embodiments thereof, and with reference to the appended drawings. Fig. 4 is a longitudinal sectional view of an ultrasonic atomizing inhaler which incorporates the first preferred embodiment of the oscillating construction of the present invention. In this figure, the reference numeral 1 generally denotes the ultrasonic inhaler as a whole, and this is made up of a main body assembly 2, a liquid supply assembly 3, and an inhalation unit 4. The main body assembly 2 defines the external contour of the ultrasonic inhaler, and comprises a main body casing 5 and a bottom plate 6. In the main body casing 5 there are housed a pair of batteries 9, 9 in a battery receiving portion thereof, and a power plug 8 with a power source circuit board 7 is further held within the main body casing 5 below said batteries 9, 9. The bottom plate 6 serves for closing the bottom of the main body casing 5 and for retaining the batteries 9, 9 and the power plug 8 therein. An oscillation circuit base board 11 is fitted parallel to the batteries 9, 9 at one side thereof, and bears an electronic circuit unit 10 including for example an oscillation circuit, as will be described later. A micro switch 12 is provided for controlling the apparatus, and is covered by a slidable switch cover 15. And a drive circuit base board 14 is provided at the top end of the main body 5, just below a top wall portion 5a thereof, for driving an oscillation element 13 which will be particularly described hereinafter. On the other side of the top wall portion 5a are provided the liquid supply assembly 3 and the inhalation unit 4. When the ultrasonic inhaler is not in use, a hygienic cap 21, shown in Fig. 4 by double dotted lines only, covers both these assemblies. The liquid supply assembly 3, which will be discussed in greater detail later, comprises a storage bottle 16 for containing water or liquid medication and a liquid supply nozzle 17 fitted into said storage bottle 16 for allowing the controlled removal of liquid therefrom to the inhalation unit 4. The inhalation unit 4 comprises an inhalation nozzle 20 adapted to be approached to the nose and mouth of a user, and a horn unit 19 which has an oscillating atomization plate 18 integrally formed at the small end 32 of a rigid cone shaped portion 19a and an ultrasonic oscillation element 13 fitted at the larger end 31 of said rigid cone shaped portion 19a. The main body casing 5, the bottom plate 6, the switch cover 15, and the hygienic cap 21 are made of a material such as ABS resin, while the storage bottle 16, the liquid supply nozzle 17, and the inhalation nozzle 20 are made of a material such as styrene resin. In detail, the horn unit 19 is mounted at the lower portion of the top wall portion 5a of the main body casing 5 of the ultrasonic inhaler, with the ultrasonic oscillating element 13 facing towards the inside and the oscillating atomization plate 18 facing outwards, and the inhalation nozzle 20 is detachably mounted to said top wall portion 5a over said horn unit 19 with its opening confronting the oscillating plate 18 and facing outwards. And the storage bottle 16 is detachably mounted at the upper portion of the top wall portion 5a, with the liquid supply nozzle 17 fitted thereinto substantially positioned at the lowest point thereof, and with the lower end of said liquid supply nozzle 17 positioned very close to the oscillating atomization plate 18 as will be explained hereinafter in detail. Thus, when it is desired to use this ultrasonic inhaler, first the user - who has, as will be more particularly explained later in this specification, previously filled the storage bottle 16 with liquid such as water or medicine which is to be atomized and inhaled - removes the hygienic cap 21, and, after approaching his or her mouth and nose near the opening of the inhalation nozzle 20, switches ON the microswitch 12 by pushing appropriately on the switch cover 15. Thereby, the oscillation circuit of the electronic circuit unit 10 drives the ultrasonic oscillating element 13 of the horn unit 19 to oscillate at an ultrasonic frequency, as will be particularly described later, and this causes the atomization plate 18 to similarly oscillate with a considerable amplitude, due to the amplifying effect provided by the rigid cone shaped portion 19a. As will be explained shortly, a controlled supply of the liquid in the storage bottle 16 is provided to this atomization plate 18, and thus the vibration at ultrasonic frequency of the oscillation plate 18 atomizes this liquid into very minute droplets, which drift away from the atomization plate 18 in the direction indicated by the arrow A in Fig. 4 through the inhalation nozzle 20 to enter the mouth and nose of the user of the ultrasonic inhaler 1, as desired, to provide medication and/or humidification of the user's larynx. Now, the detailed construction of the storage bottle 16, the liquid supply nozzle 17, and the horn unit 19 will be explained, with reference to Figs. 2 and 3. In Fig. 2, there is shown a sectional view of the bottle 16, the nozzle 17 fitted thereinto, and the horn unit 19 taken in the same plane as In Fig. 4, but in enlarged scale; and Fig. 3 shows these parts as fitted to the top wall portion 5a of the main body casing 5. The storage bottle 16 is shaped in an inverted U shape as seen from the front, as in Fig. 3, and further is shaped in a rectangular shape as seen from the side as in Fig. 4. As previously mentioned, the bottle 16 is formed from a transparent or translucent styrene resin. And from the bottom surface 16a of the storage bottle 16 there projects a tubular nozzle fitting member 22. Into this tubular nozzle fitting member 22 there is fitted the aforementioned liquid supply nozzle 17, with the interposition therebetween of a tube 23 made of a rubber like elastic material. This tube 23 is required to be somewhat distended, in order to be fitted over the nozzle 17, and further is then required to be somewhat compressed, in order for the nozzle 17 with said tube 23 fitted thereover to be fitted into the nozzle fitting member 22; accordingly, when this fitting has been accomplished, the inner cylindrical surface of the tube 23 is closely and sealingly contacted to the portions of the outer surface of the nozzle 17 with which it is in contact, and the outer cylindrical surface of said tube 23 is similarly closely and sealingly contacted to the inner cylindrical surface of the tubular nozzle fitting member 22. And thereby the nozzle 17 is securely held in said nozzle fitting member 22. The form of the liquid supply nozzle 17 will now be explained. This nozzle 17 has a generally cylindrical shape, with a flange 28a formed near its one end 30 which is outside the storage bottle 16 and another smaller flange 28b formed near its other end 23 which is inside said storage bottle 16. The tube 23 is fitted between these two flanges 28a and 28b and is axially retained between them. And the larger lower flange 28a further serves for locating the nozzle 17 relative to the bottle 16, when said nozzle is fitted into the tubular nozzle fitting member 22 of said bottle 16. A plurality of circumferential grooves 26 (two in the shown construction) are formed as extending round the portion of the nozzle 17 between said two flanges 28a and 28b; and a pair of liquid supply grooves 24 extending in the axial direction of the nozzle 17, thus being orthogonal to the circumferential grooves 26, and spaced diametrically opposite from one another around said nozzle 17, are formed as cut quite deeply into the material of said nozzle 17; these liquid supply grooves 24 are extremely fine, for proper obtaining of capillary action as will be explained hereinafter, and function for leading liquid from the interior of the storage bottle 15 to the atomization plate 18 of the horn assembly 19. The circumferential grooves 26 are provided for forming temporary storage reservoirs for fluid which is being taken out from the storage bottle 16 through the liquid supply grooves 24, as will be explained in greater detail later. And through the two flanges 28a and 28b and through the flange portions remaining between the grooves 26 on either side thereof there are cut, superimposed upon the outer portion of the liquid supply grooves 24 and wider than said liquid supply grooves 24, two air supply grooves 25; these air supply grooves 25 are substantially wider than the liquid supply grooves 24, and function for leading air from the outside to the interior of the storage bottle 16. The end 27 of the liquid supply nozzle 17 inside the storage bottle 16 is quite long, and has the continued end portion of the liquid supply grooves 24 formed on it, thus appropriately leading said liquid supply grooves 24 well into the liquid inside said bottle 16. And, as best seen in the sectional view of Fig. 2, the lower end 30 of the liquid supply nozzle 17 is formed with two projecting end portions 29a and 29b separated by the two liquid supply grooves 24: the longer projecting end portion 29b is substantially longer than the other portion 29a, being formed in a substantially triangular shape, and its inside surface 29d is substantially planar; while the shorter projecting end portion 29a is cut off straight, having a substantially straight downwardly facing edge 29c. The horn unit 19 comprises the rigid cone shaped portion 19a, and at the larger end 31 of said portion 19a is fitted the ultrasonic oscillation element 13. At the smaller end 32 of said rigid cone shaped portion 19a there is integrally formed the oscillating atomization plate 18, in an orientation perpendicular to the axis of said cone shape thereof; and this atomization plate 18 is in this first preferred embodiment of the present invention formed as a disk with a portion thereof defined by a chord 35 cut away, leaving the remainder 33 of its circumferential circle intact. Thus, the surface 34 of the plate 18 facing away from the cone shaped portion 19a is substantially planar. As best shown in Fig. 2, the horn unit 19 is so mounted to the top wall portion 5a of the main body casing 5, relative to the storage bottle 16, that this surface 34 of said atomization plate 18 confronts the aforementioned substantially planar inside surface 29d of the longer projecting lower end portion 29b of the liquid supply nozzle 17 with a certain very narrow gap 36 being defined therebetween. And, moreover, in this position the edge of the plate 18 defined by the chord 35 confronts the flat lower edge 29c of the shorter projecting end portion 29a of the liquid supply nozzle 17 with another very narrow gap 37 being defined therebetween. Accordingly, it is seen that, in this first preferred embodiment of the present invention, the atomization plate 18 is formed with a boundary divided into two parts, which are generally at different distances from the center of said atomization plate 18. And the surface 34 of said atomization plate 18 can be considered as made up of two regions 34a and 34b: the region 34a is the one principally delimited by the chord line 35, while the other region 34b is the one principally delimited by the remainder 33 of the circumference of the disk shape of said atomization plate 18. The boundary between these two regions is necessarily conceptually vague, and it is accordingly indicated in Fig. 3 by a dashed line. Thus, when the ultrasonic inhaler 1 as described above is being used, the atomization plate 18 is caused to vibrate at ultrasonic frequency as explained above; or, more exactly, the region 34b of said atomization plate 18, which is the one principally delimited by the remainder 33 of the circumference of the disk shape of said atomization plate 18, is caused to vibrate at high amplitude, since the frequency of the ultrasonic excitation provided to the ultrasonic oscillating element 13 by the oscillation circuit of the electronic circuit unit 10 is so chosen; but, since the region 34a of the atomization plate 18 which is principally delimited by the chord line 35 has a different fundamental frequency, it does not vibrate so much or with such a high amplitude. At this time, liquid in the storage bottle 16 passes by the action of gravity and also by capillary action from the interior of said bottle 16, into the upper ends of the liquid supply grooves 24 where they are formed in the inwardly projecting portion 27 of the nozzle 17, and down through these grooves 24. The two circumferential grooves 26 define intermediate fluid reservoirs along this fluid flow path, said reservoirs being communicated to the sides of the grooves 24 at intermediate points therealong. Then the liquid flows to the outside of the bottle 16 down through the portions of the liquid supply grooves 24 formed in the outwardly projecting portion 30 of the nozzle 17, and therefrom flows to the surfaces 29c and 29d of the projecting end portions 29a and 29b, from which it flows across the narrow gaps 37 and 36 respectively, to the surface 34 of the atomization plate 18 - in particular, to the region 34a thereof which is principally delimited by the chord line 35, and which, as explained above, is not vibrating with a very great amplitude. From this region 34a, the supplied liquid quickly creeps to the other region 34b, which is the one principally delimited by the remainder 33 of the circumference of the disk shape of said atomization plate 18, and which as explained above is vibrating at an ultrasonic frequency with a comparatively great amplitude. Then, as outlined previously, this liquid is atomized by the vibration at ultrasonic frequency of said portion 34b of the atomization plate 18, and drifts away from said plate 18 to pass through the aperture of the inhalation nozzle 20, in the direction indicated in Fig. 4 by the arrow A, to enter the mouth and nose of the user of the ultrasonic inhaler 1. Meanwhile, an amount of air substantially equal in volume to the amount of fluid thus taken out from the bottle 16 enters into the interior of said bottle 16 through the two air supply grooves 25. And since a relatively large volume of liquid may be satisfactorily supplied by the action of gravitation and by capillary action through the two liquid supply grooves 24, and since further reservoirs of liquid en route are provided by the circumferential grooves 26, this supply of liquid to be atomized is performed smoothly and efficiently, according to the amount required, and interruption of liquid supply is never likely to occur. During this liquid supply process, in fact mostly the liquid flows from the liquid supply grooves 24 onto the surface 29d of the longer projecting end portion 29b of the liquid supply nozzle 17, said end portion 29b being triangular in shape and the defining edge of its said surface 29d coming closest to the defining chord edge 35 of the above described non strongly vibrating region 34a of the oscillation plate 18 at two points P and Q (see Fig. 3). Then this liquid flows from this surface 29d over the gap 36 to said non strongly vibrating region 34a of the oscillation plate 18, principally around the two points P and Q, and accordingly is supplied to the strongly vibrating region 34b of the oscillation plate 18 from two directions, i.e. from the vicinities of said points P and Q. Since the liquid is thus supplied to substantially the whole circumference 33 of said strongly vibrating region 34b from these two directions, the area of the atomization plate 18 utilized for atomization is broadened. Furthermore, even when the conditions of liquid supply, such as the volume thereof, or the viscosity of the liquid and so on, at the non strongly vibrating region 34a of the oscillation plate 18 have changed, since this portion of the oscillation plate 18 does not substantially contribute to the atomization action for the liquid, no problems arise, and the oscillation of the strongly vibrating region 34b of said atomization plate 18 is not substantially influenced or affected. Therefore, even when the load imposed on the oscillation plate 18 by the liquid changes, the resonance frequency of the operative portion thereof, i.e. of the strongly vibrating region 34b thereof, is not substantially altered, and the atomization action can be maintained. Now, when the ultrasonic inhaler 1 is switched off, with the atomization plate 18 not vibrating, then by the action of the surface tension of the liquid in the storage bottle 16 no undue supply of liquid from the bottle 16 can occur, and no improper dribbling of liquid can occur. This is further properly ensured by arranging that the liquid supply grooves 24 and the air supply grooves 25, as well as the circumferential grooves 26, are of appropriate dimensions in view of the surface tension and the viscosity, as well as possibly other characteristics, of the type of liquids to be used for atomization. Since by the shown construction for the ultrasonic inhaler and for the nozzle 17 the bottle 16 is positioned above the atomization unit 4, with the nozzle 17 at the bottom side of said bottle 16, not only is capillary action relied upon for performing liquid supply but also gravitational action is utilized, and thus there is no problem in supplying for atomization even the last few drops of the liquid contained in the bottle 16, which accordingly may satisfactorily be drained to its uttermost dregs. But this is not intended to be limitative of the present invention, and it would be possible, also, to supply the liquid to the region 34a of the atomization plate 18 which is principally delimited by the chord line 35 via a bottle located below said atomization plate by using an absorptive bar, in the general manner shown in Fig. 1 and discussed hereinabove. In fact, in Figs. 5a and 5b, there are shown the horn assembly 19 and the liquid supply system relating to a second preferred embodiment of the present invention, in which this concept is implemented. In these figures, the orientation of the atomization plate 18 is opposite to the orientation of the corresponding atomization plate of the first preferred embodiment of the present invention as shown in Figs. 2 and 3. In these figures, parts which correspond to parts of the first preferred embodiment shown in Figs. 2 through 4 and discussed above, and which have the same functions, are denoted by the same reference symbols. The way in which this second preferred embodiment operates will be clear to one of ordinary skill in the ultrasonic atomizer art, based upon the disclosure hereinabove, and hence will not be expatiated upon. Again in this second preferred embodiment, the liquid is supplied, by an absorptive bar 40 this time, to a region 34a of the surface 34 of the atomization plate 18 which is principally delimited by the chord line 35, and which is not vibrating with a very great amplitude. From this region 34a, the supplied liquid quickly creeps to the other region 34b, which is the one principally delimited by the remainder 33 of the circumference of the disk shape of said atomization plate 18, and which as in the case of the first preferred embodiment is vibrating at an ultrasonic frequency with a comparatively great amplitude. Then, as outlined previously, this liquid is atomized by the vibration at ultrasonic frequency of said portion 34b of the atomization plate 18, and drifts away from said plate 18 to pass to enter the mouth and nose of the user of the ultrasonic inhaler 1. Accordingly, this second preferred embodiment of the present invention has the same advantages as outlined above with regard to the first preferred embodiment. In Figs. 6a and 6b, there are shown the horn assembly 19 and the liquid supply system relating to a third preferred embodiment of the present invention. In these figures, the orientation of the atomization plate 18 is the same as the orientation of the corresponding atomization plate of the first preferred embodiment of the present invention as shown in Figs. 2 and 3, and is opposite to that of the second preferred embodiment. In these figures, carts which correspond to parts of the first preferred embodiment shown in Figs. 2 through 4 and discussed above, and of the second preferred embodiment shown in Figs. 5a and 5b, and which have the same functions, are denoted by the same reference symbols. Again in this third preferred embodiment, the liquid is supplied, by an absorptive bar 51 this time which is shaped in an inverted J shape and leads said liquid by capillary action from a tank 50, to a region 34a of the surface 34 of the atomization plate 18 which is not vibrating with a very great amplitude. From this region 34a, the supplied liquid quickly creeps to the other strongly vibrating region 34b. Then, as outlined previously, this liquid is atomized and drifts away to enter the mouth and nose of the user. The way in which this third preferred embodiment operates will be clear to one of ordinary skill in the ultrasonic atomizer art, based upon the disclosure hereinabove, and hence will not be expatiated upon. Accordingly, this third preferred embodiment of the present invention has the same advantages as outlined above with regard to the first and second preferred embodiments. In Figs. 7a and 7b, there are shown the horn assembly 19 and the liquid supply system relating to a fourth preferred embodiment of the present invention. In this fourth preferred embodiment, the horn assembly is configured differently, being a stepped shape horn 60; however, the oscillating plate 18 is of the same type as in the first through the third preferred embodiments discussed above. In these figures, parts which correspond to parts of the first through third preferred embodiments shown in Figs. 2 through 6 and discussed above, and which have the same functions, are denoted by the same reference symbols. Again in this fourth preferred embodiment, the liquid is supplied by an absorptive bar 64 to a region 34a of the surface 34 of the atomization plate 18 which is not vibrating with a very great amplitude. From this region 34a, the supplied liquid quickly creeps to the other strongly vibrating region 34b. Then, as before, this liquid is atomized and drifts away to enter the mouth and nose of the user. The way in which this fourth preferred embodiment operates will be clear to one of ordinary skill in the ultrasonic atomizer art, based upon the disclosure hereinabove, and hence will not be expatiated upon; and it has the same advantages as outlined above with regard to the first through the third preferred embodiments. As a further possible modification of the present invention, although this is not shown in any of the above figures, it could be possible for the oscillation plate 18 to be formed as a rectangular member with long sides and short sides. Thus, it is seen that, according to the horn oscillation unit of this invention, since the oscillation plate comprises two regions having different vibrational characteristics, and in the shown preferred embodiments having different distances between their edges and their center, by supplying liquid to one of the regions and producing atomization action in the other region, the fluctuations in the load imposed by the liquid do not affect the atomization action, whereby an ultrasonic atomizer which is immune to fluctuations in load can be obtained. Furthermore, since the liquid is supplied to the oscillation plate in two directions separately (from the regions around the points P and Q in Fig. 3), the oscillation surface of the oscillating plate is well utilized, and the atomization efficiency is improved. Now, another aspect of the present invention will be discussed. Fig. 8 shows a circuit diagram for a drive circuit 72 on the base board 14 for driving the oscillation element 13, which is provided at the top end of the main body 5 just below the top wall portion 5a thereof, in a fifth preferred embodiment of the present invention; the remainder of this fifth preferred embodiment is like the first preferred embodiment shown above and described with reference to Figs. 2 through 4, and hence will not be described in detail. The voltage of the batteries 9 is raised by a DC - DC converter 74 and is supplied as a power source voltage to this drive circuit 72. The drive circuit 72 is a per se known type of blocking oscillator, and comprises a transistor Tr, a pair of transformers T1 and T2, a capacitor C, a resistor R, and so on, and by the action of a switch 75 it is possible to select one of the transformers T1 and T2 for use therein. In other words, depending upon whether the switch 75 is set to the a side or to the b side, one or the other of the transformers T1 and T2 of the oscillation circuit 72 is selected, and thus the oscillation circuit 72 can oscillate at two different frequencies. And the frequencies which may be switched over are designed so as to correspond to the resonance frequencies of the portion 34a of the oscillation plate 18 largely delimited by the chord 35 and the other portion 34b of said oscillation plate 18 largely delimited by the remainder 33 of the circumference of the disk shape thereof. In this ultrasonic inhaler, when the switch 75 is set to the side a or to the side of the transformer T1, and the power is turned ON for starting oscillation for instance at the higher of the two frequencies, the ultrasonic oscillation element 13 oscillates at this higher frequency, and the ultrasonic waves thereby generated are transmitted through the main body 19a of the horn assembly 19 to the oscillation plate 18, causing the portion 34a thereof largely delimited by the chord 35 to vibrate strongly; and thus the liquid existing adjacent to said portion 34a is atomized. On the other hand, when the switch 75 is set to the side b or to the side of the transformer T2, the oscillation circuit 72 starts oscillating while connected to the transformer T2. If this oscillation frequency is lower than the one which was produced when the oscillation circuit 72 was connected to the side of the transformer T1, the ultrasonic oscillation element 13 oscillates at a frequency which is lower than the one which was produced when the switch 75 was selected to the side of the transformer T1. Accordingly, this time, the other portion 34b of said oscillation plate 18 largely delimited by the remainder 33 of the circumference of the disk shape of the oscillation plate 18 oscillates. And the liquid existing adjacent to this other portion 34b is atomized. And, since the resonance frequencies of the two portions 34a and 34b differ from each other, the resulting particle diameters of the atomized liquid also differ. Although the horn was of a conical type in the above described fifth preferred embodiment, the concept thereof could be likewise implemented by using horns of other types, such as a step horn and so on. And, although the oscillation plate was defined into two regions having different resonance frequencies by cutting off a portion of a circular plate delimited by a chord in the above described embodiment, it is also possible to define the atomization portion with a rectangular shape having long sides and short sides, so as similarly to define two regions having different resonance frequencies. And, although in the above described embodiment supply of liquid to the atomization portion was made by an absorptive band, it is also possible to use other means such as a liquid supply nozzle and so on. Thus, according to this aspect of the present invention, since atomization in different particle diameters is possible by a simple switch over of a switch, thereby one unit of the ultrasonic inhaler can perform the treatment of both the deep part of the trachea and the shallow part of the larynx, according to the current medical requirements, and the present invention can further be adapted to a wide variety of medications. Further, in Fig. 9a there is shown a side view, and in Fig. 9b there is shown an end on view, of a sixth preferred embodiment of the present invention; again, like parts are denoted by like reference numerals. This structure is intended for use with a two frequency type of drive circuit 72 like that of Fig. 8, and differs from the previous ones in that the oscillation plate 18 is formed as a disk shape with two diametrically opposite portions cut away by two chords, so as to define two portions 34a thereof largely delimited by the chord 35 which tend to vibrate at one characteristic frequency and one intermediate portion 34b of said oscillation plate 18 largely delimited by the remainder 33 of the circumference of the disk shape thereof which tends to vibrate at the other characteristic frequency. The effects and advantages are the same as in the fifth preferred embodiment described above, and hence detailed discussion thereof will be omitted.

Claims: An oscillating construction for an ultrasonic atomizing inhaler, comprising an oscillation element (18) which is excited to vibrate ultrasonically, characterized in that said element (18) comprises two adjoining regions (34a, 34b) which have substantially different vibrational characteristics. An oscillating construction for an ultrasonic atomizing inhaler according to claim 1, wherein said oscillation element is shaped substantially as a plate (18). An oscillating construction for an ultrasonic atomizing inhaler according to claim 2, wherein said two adjoining regions (34a, 34b) of said plate shaped oscillation element (18) have respective edges which are separated by different distances from a central point of said plate (18). An oscillating construction for an ultrasonic atomizing inhaler according to claim 3, wherein said plate shaped oscillation element (18) is shaped as a circular disk with a portion cut away by a chord (35). An oscillating construction for an ultrasonic atomizing inhaler according to claim 3, wherein said plate shaped oscillation element (18) is shaped as a circular disk with two portions cut away by two chords. An oscillating construction for an ultrasonic atomizing inhaler according to claim 5, wherein said two portions cut away by two chords are substantially diametrically opposite, on said plate shaped oscillation element (18). An oscillating construction for an ultrasonic atomizing inhaler according to anyone of the preceding claims, further comprising a means for exciting said oscillation element (18) so as to cause it to vibrate ultrasonically, selectable to either of two different frequencies.

Inventors: ASAI, KEI OMRON TATEISI ELECTRONICS CO., MATSUMOTO, KAZUHIRO OMRON TATEISI ELECTRONICS CO., YAMAMOTO, HIROHITO OMRON TATEISI ELECTRONICS CO.
Applicants: OMRON TATEISI ELECTRONICS CO.
Application year: 1985
Main classification: A61M15
IPC codes: B05B17, A61M15