Ultrasonic atomizer, ultrasonic inhaler and method of controlling same

• US 6,651,650 B1
• Filed: 10/04/1994
• Issued: 11/25/2003
• Est. Priority Date: 04/09/1992
• Status: Active Grant

• Current Assignee: Omron Healthcare Company Limited (Omron Corporation)
• Original Assignee: Omron Corporation
• Inventors: Obata, Masaru, Asai, Kei, Yamamoto, Hirohito
• Primary Examiner(s): Lewis, Aaron J.
• Application Number:
  US08/313,249
• Time in Patent Office: 3,339 Days
• Field of Search: 128/200.16, 128/200.18, 239/102.2, 239/142, 239/145, 239/343, 239/360, 239/396, 239/397, 239/505, 239/506, 239/516, 239/517, 239/519, 239/524, 239/552, 239/553.3, 239/557, 239/558
• US Class Current: 128/200.16
• CPC Class Codes: A61M 15/0083 Timers
• CPC Class Codes: A61M 15/0085 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: B05B 17/0623 coupled with a vibrating horn
• CPC Class Codes: B05B 17/063 having an internal channel for supplying the liquid or other fluent material
• CPC Class Codes: B05B 17/0638 spray being produced by discharging the liquid or other fluent material through a plate comprising a plurality of orifices
• CPC Class Codes: B05B 9/03 characterised by means for supplying liquid or other fluent material B05B9/002 takes precedence

Abstract

A bush (31) is fitted into a housing (10) and an ultrasonic pump (12) is supported liquid tightly by the bush (31). The ultrasonic pump (12) is constituted by a pump shaft (21) formed to include a pump bore (22) passing through it axially and having upper and lower ends which are open, and an ultrasonic vibrator (23) mounted on the pump shaft (21) in the vicinity of the midpoint thereof in terms of the axial direction. A liquid vessel (16) is mounted in the housing (10) in a freely attachable and detachable manner, and the lower end portion of the pump shaft (21) is received inside the liquid vessel (16). A cap (15) is freely detachably attached to the upper end portion of the housing (10) so as to cover the upper end portion of the pump shaft (21). The top side of the cap (15) is provided with a spray port (51), and a step portion (57) is formed for supporting a mesh plate (14) at the periphery thereof at a position below the spray port (51). A compression spring (42) is provided between a portion of the top side of the cap and the mesh plate. The mesh plate (14) is formed to have a multiplicity of minute holes (14a) and is held in pressured contact with the upper end face of the pump shaft (21) by the compression spring (42).

Claims

1. An ultrasonic atomizer comprising:

an ultrasonic pump comprising a pump shaft having an upper end, a lower end, and a pump bore passing axially through said pump shaft to form openings in the upper and lower ends,

said ultrasonic pump further comprising an ultrasonic vibrator mounted on said pump shaft substantially at a midpoint thereof with respect to the axial direction of said pump shaft;

a liquid vessel arranged such that it is penetrated by a lower end of said pump shaft;

a mesh plate placed on a face of the upper end of said pump shaft, said mesh plate having a plurality of minute holes; and

a resilient biasing member for biasing said mesh plate toward the upper end face of said pump shaft, said mesh plate intermittently contacting the upper end face of said pump shaft, wherein the upper end face of said pump shaft comprises a shape in which the upper end face is slightly and smoothly curved so as to attain maximum height at the position of the opening in the upper end of the pump bore and to diminish in height as the periphery is approached.

2. An ultrasonic atomizer according to claim 1, further comprising:

a housing configured to support said ultrasonic pump, said liquid vessel being attached to said housing in a freely detachable manner; and

a cap attached to a portion of said housing in a freely detachable manner so as to cover the upper end of said pump shaft;

a top side of said cap being provided with a spray port, said cap having a step portion for supporting said mesh plate at the periphery thereof at a position beneath said spray port, said resilient biasing member being provided between a portion of the top side of said cap and said mesh plate.

3. An ultrasonic atomizer according to claim 1, wherein said mesh plate is curved slightly by said resilient biasing member at a peripheral edge of said mesh plate extending outwardly from the upper end face of said pump shaft, and wherein the curvature of the upper end face of said pump shaft, the elastic force of said resilient member, and the strength of said mesh plate are determined such that the degree of curvature of said mesh plate is less than the degree of curvature of the upper end face of said pump shaft.

4. An ultrasonic atomizer according to claim 1, wherein said resilient biasing member comprises a compression coil spring.

5. An ultrasonic atomizer according to claim 1, wherein the minute holes of said mesh plate flare outwardly in a direction extending from a top side to a bottom side of said mesh plate.

6. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises a shape in which the minute holes flare outwardly in a direction extending from a top side to a bottom side of said mesh plate, and wherein a recess is formed in the top side of said mesh plate between mutually adjacent ones of the minute holes.

7. An ultrasonic atomizer according to claim 1, wherein cut-outs of different size are formed in the periphery of said mesh plate at least at two locations other than locations having point symmetry about the center of said mesh plate.

8. An ultrasonic atomizer according to claim 1, wherein said minute holes are formed at equal intervals along the sides of a plurality of regular hexagons having diagonals that vary at fixed distances.

9. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises a small area devoid of minute holes said small area being surrounded by said minute holes.

10. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises a small area devoid of minute holes, said small area opposing the opening in the upper end of the pump bore of said pump shaft over a region broader than said opening.

11. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises an annular plate at a peripheral portion of said mesh plate, wherein said annular plate causes the biasing force produced by said biasing member to be applied uniformly to said mesh plate.

12. An ultrasonic atomizer according to claim 1, further comprising a bush for encircling and supporting a portion of said pump shaft excluding upper and lower end portions of said pump shaft, said bush being liquid-tight;

an annular lip seal, in liquid-tight contact with a portion of the pump shaft situated higher than said ultrasonic vibrator, said annular lip seal being formed integrally at least at two locations, one above the other, on an upper portion of said bush, and a gap being provided between said portion of the pump shaft and said bush between the annular lip seal at the at least two locations.

13. An ultrasonic atomizer according to claim 1, further comprising:

a bush for encircling and supporting a portion of said pump shaft excluding upper and lower end portions of said pump shaft said bush being liquid tight;

a housing into which said bush is fitted in a liquid tight arrangement; and

a cap attached in a freely detachable manner to an annular projecting wall that is formed on said housing about the upper end portion of said pump shaft, said cap covering the upper end portion of said pump shaft when attached;

a reservoir having (i) a bottom surface formed by a top side of said bush and (ii a peripheral wall formed by at least one of said cap and said annular projecting wall.

14. An ultrasonic atomizer according to claim 1, wherein a lower end of said pump shaft is disposed in close proximity to a bottom surface or side surface of said liquid vessel such that residual liquid remaining inside said liquid vessel is pumped upon attaching to the lower end of the pump shaft by surface tension.

15. An ultrasonic atomizer according to claim 1, wherein said liquid vessel is formed to have a recess for collecting the residual liquid remaining inside said liquid vessel, and the lower end of said pump shaft is disposed so as to face said recess.

16. An ultrasonic atomizer according to claim 1, further comprising:

a drive circuit for driving the ultrasonic vibrator of said ultrasonic pump;

an operating switch;

first control means responsive to an on/off operation of said operating switch for controlling the driving of said ultrasonic vibrator by said drive circuit; and

second control means for determining, in response to said operating switch being turned on and off at least one time, an OFF time for automatic intermittent operation based on the ON time and the OFF time of said operating switch, and for controlling said drive circuit such that said ultrasonic vibrator is driven using the ON time and the OFF time determined by said second control means.

17. An ultrasonic atomizer in which a liquid inside a liquid vessel is supplied to an inlet side of a mesh plate formed to have a plurality of minute holes and said mesh plate is vibrated by an ultrasonic vibrator, whereby the liquid supplied to the inlet side of the mesh plate is sprayed from an outlet side of said mesh plate, said mesh plate comprising a plate-shaped body having a recess between mutually adjacent ones of said minute holes, said plate-shaped body being formed such that peripheral wall surfaces of said minute holes project from the inlet side.

18. An ultrasonic atomizer according to claim 17, wherein said minute holes flare outwardly from the inlet side to the outlet side.

19. An ultrasonic atomizer according to claim 17, wherein cut-outs of different size are formed in the periphery of said mesh plate at least at two locations other than locations having point symmetry about the center of said mesh plate.

20. An ultrasonic atomizer according to claim 17, wherein said minute holes are formed in said mesh plate at equal intervals along sides of a multiplicity of regular hexagons having diagonals that vary at fixed distances.

21. An ultrasonic atomizer according to claim 17, wherein said mesh plate comprises a small area devoid of minute holes, said small area being surrounded by said minute holes.

22. An ultrasonic atomizer according to claim 17, wherein said mesh plate comprises a small area devoid of minute holes said small area opposing a liquid-supply port over a region broader than said supply port.

23. An ultrasonic atomizer comprising:

an ultrasonic pump comprising a pump shaft having an upper end, a lower end, and a pump bore passing axially through said pump shaft to form openings in the upper and lower ends, said ultrasonic pump further comprising an ultrasonic vibrator mounted on said pump shaft substantially at a midpoint thereof with respect to the axial direction of said Dump shaft;

a liquid vessel arranged such that it is penetrated by a lower end of said pump shaft;

a mesh plate placed on a face of the upper end of said pump shaft, said mesh plate having a plurality of minute holes;

a resilient biasing member for biasing said mesh plate toward the upper end face of said pump shaft; and

an annular plate provided on a peripheral portion of said mesh plate, or a spacer provided between said mesh plate and the upper end face of said pump shaft, to cause the biasing force produced by said biasing member to be applied uniformly to said mesh plate.

24. An ultrasonic atomizer having an ultrasonic pump comprising a pump shaft formed to have a pump bore passing through it axially and having open upper and lower ends, and an ultrasonic vibrator mounted on the pump shaft in the vicinity of the midpoint thereof with respect to the axial direction, wherein a liquid inside a liquid vessel is pumped up from the lower end of said pump bore and the liquid is supplied to a mesh plate from the upper end of said pump bore so as to be sprayed, and wherein a bush is provided for encircling and supporting liquid tightly a portion of said pump shaft of said ultrasonic pump excluding upper and lower end portions of said pump shaft, an annular seal lip, in intimate liquid-tight contact with a portion of said pump shaft situated higher than said ultrasonic vibrator, is formed integrally at least at two locations, one above the other, on an upper portion of said bush, and a gap is provided between said portion of the pump shaft and said bush between said annular seal lips at the at least two locations.

25. An ultrasonic atomizer comprising:

an ultrasonic pump comprising a pump shaft having an upper end, a lower end, and a pump bore passing axially through said pump shaft to form openings in the upper and lower ends, said ultrasonic pump further comprising an ultrasonic vibrator mounted on said pump shaft substantially at a midpoint thereof with respect to the axial direction of said pump shaft;

a liquid vessel arranged such that it is penetrated by a lower end of said pump shaft;

a mesh plate placed on a face of the upper end of said pump shaft, said mesh plate having a plurality of minute holes;

a resilient biasing member for biasing said mesh plate toward the upper end face of said pump shaft;

a bush for encircling and supporting liquid tightly a portion of said pump shaft of said ultrasonic pump excluding upper and lower end portions of said pump shaft;

a housing in which said bush is fitted liquid tightly; and

a cap attached in a freely detachable manner to an annular projecting wall that is formed on said housing about the upper end portion of said pump shaft, said cap for covering the upper end portion of said pump shaft;

a reservoir having a top side of said bush forming a bottom surface and at least one of said cap and said annular projecting wall forming a peripheral wall.

26. An ultrasonic atomizer according to claim 25, wherein a top side of said cap is provided with a spray port, a step portion is formed for supporting said mesh plate at the periphery thereof at a position beneath said spray port, and said resilient biasing member is provided between a portion of the top side of said cap and said mesh plate.

27. An ultrasonic atomizer having:

a liquid vessel for accommodating a liquid to be atomized; and

an ultrasonic pump comprising a pump shaft having a lower end situated inside said liquid vessel and formed to have a pump bore passing through the pump shaft axially and having open upper and lower ends, and an ultrasonic vibrator mounted on the pump shaft, wherein a bottom surface or a surface of said liquid vessel is formed to be oblique with respect to a horizontal plane;

a lower end of said pump shaft being disposed in close proximity to the oblique bottom surface or the oblique side surface of said liquid vessel such that residual liquid remaining inside said liquid vessel is pumped upon attaching itself to the lower end of the pump shaft by surface tension and ultrasonic vibration.

28. An ultrasonic atomizer according to claim 27, wherein said liquid vessel comprises a recess for collecting the residual liquid remaining inside said liquid vessel, and wherein the lower end of said pump shaft is disposed so as to face said recess.

29. An ultrasonic atomizer according to claim 27, wherein said liquid vessel is freely attachable and detachable.

30. An ultrasonic inhaler having an ultrasonic pump comprising a pump shaft formed to have a pump bore passing axially therethrough, said pump further comprising an ultrasonic vibrator mounted on said pump shaft, wherein liquid is pumped through said pump shaft and sprayed by ultrasonic vibration, said inhaler comprising:

a drive circuit for driving the ultrasonic vibrator of said ultrasonic pump;

an operating switch;

first control means responsive to on/off operation of said operating switch to control the driving of said ultrasonic vibrator by said drive circuit; and

second control means for determining, in response to said operating switch being turned on an off at least one time, an ON time and an OFF time for automatic intermittent operation based on the ON time and the OFF time of said operating switch, and for controlling said drive circuit in such that said ultrasonic vibrator is driven using the ON time and the OFF time determined by said second control means

third control means for controlling said drive circuit to drive said ultrasonic vibrator continuously in response to an ON time of said operating switch that is greater than a first predetermined time.

31. An ultrasonic inhaler according to claim 30, wherein said second control means performs automatic intermittent operation in response to on/off operation of said operating switch being repeated a prescribed number of times.

32. An ultrasonic inhaler according to claim 31, wherein said second control means transitions to automatic intermittent operation upon verifying that the ON time of said operating switch for the last time in the prescribed number of times is greater than a second predetermined time.

33. An ultrasonic atomizer according to claim 30, further comprising an automatic intermittent-operation mode switch, said second control means initiating automatic intermittent operation in response to an input from said automatic intermittent-operation mode switch.

34. A method of controlling an ultrasonic inhaler having an ultrasonic pump comprising a pump shaft formed to have a pump bore passing axially therethrough, and an ultrasonic vibrator mounted on said pump shaft, wherein liquid is pumped through said pump shaft and sprayed by ultrasonic vibration, said method comprising:

driving said ultrasonic vibrator during a time in which an operating switch is ON;

measuring a duration of the ON time;

halting driving of said ultrasonic vibrator during a time in which the operating switch is OFF;

measuring the duration of the OFF time;

determining an ON time and an OFF time for automatic intermittent operation based on the measured ON time and OFF time of said operating switch after said operating switch has been turned on and off and a prescribed number of times;

said ultrasonic vibrator intermittently using the determined ON and OFF times when an ON time of said operating switch is less than a predetermined time; and

driving said ultrasonic vibrator continuously when the ON time of said operating switch is greater than or equal to the predetermined time.