Droplet ejector with oscillating tapered aperture
First Claim
1. A droplet ejector device comprising:
- a vibrating surface having a tapered aperture, said aperture having first and second openings, with said first opening being larger than said second opening;
means for supplying fluid to said vibrating surface to be in surface tension contact with said first opening; and
means for vibrating said vibrating surface to eject the fluid supplied to said vibrating surface.
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Accused Products
Abstract
A fluid injection device for ejecting fluid droplets in response to electrical signals comprises an oscillating surface that has one or more tapered apertures, each aperture having a first and second opening. The first opening of each aperture is larger than the second opening. The first opening is in surface tension contact with the fluid to be ejected. The fluid interaction with the tapered aperture wall creates cycles of fluid compression and decompression inside the aperture, causing fluid to be drawn from the large opening and ejected out the small opening of the aperture. The device includes a fluid supply nozzle that transports fluid to the oscillating surface at the large opening of the apertures. A discharge valve controls the fluid supply. An electronic wave generator induces oscillation in the tapered aperture containing surface. The device is used to great advantage for fluid atomization and fluid spray.
235 Citations
29 Claims
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1. A droplet ejector device comprising:
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a vibrating surface having a tapered aperture, said aperture having first and second openings, with said first opening being larger than said second opening;
means for supplying fluid to said vibrating surface to be in surface tension contact with said first opening; and
means for vibrating said vibrating surface to eject the fluid supplied to said vibrating surface. - View Dependent Claims (2, 3, 4, 5)
a fluid supply tube for carrying said fluid, including a supply nozzle positioned in close proximity to the free end of said vibrating surface; and
a flow control valve attached to the fluid supply tube governing the movement of said fluid through said fluid supply tube.
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5. The droplet ejector device of claim 1, further comprising a means for preventing overflow of said liquid in said surface tension contact with said first opening on said vibrating surface.
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6. A method for ejecting fluid, the method comprising the steps of:
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supplying fluid to a vibrating surface having a tapered aperture with first and second openings, said first opening being larger than said second opening, said fluid being in surface tension contact with said first opening; and
oscillating said vibrating surface to eject said fluid drawn into said tapered aperture at said first opening, from said second opening.
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7. An ejection device for ejecting fluid on demand, said device comprising:
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a vibrating surface having at least one aperture, said aperture having first and second openings wherein said first opening is larger than said second opening;
an oscillator attached to the said vibrating surface for imparting oscillating motion thereto at a selected frequency; and
a liquid supply means in fluid communication with said first opening of the aperture in said vibrating surface for supplying fluid to be ejected, said supplied fluid continuously adhering to said first opening through a solid/fluid surface interaction. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A fluid ejection device comprising:
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a mechanical member constrained at a portion thereof and free to move at another portion thereof and adapted for vibrating motion at its free portion in response to oscillations;
said mechanical member having a tapered aperture in its free portion, said aperture having first and second openings wherein said first opening is larger than said second opening;
an oscillator for imparting mechanical oscillations to said mechanical member in response to an electrical signal; and
a source of fluid in fluid communication with said first opening of said tapered aperture for supplying fluid to said aperture, said fluid continuously adhering to said first opening through a solid/fluid surface interaction. - View Dependent Claims (14, 15, 16)
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17. A method for ejecting fluid droplets, said method comprising the steps of:
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a. providing a vibrating surface of selected shape having at least one aperture, said aperture having first and second openings wherein said first opening is larger than said second opening;
b. oscillating said surface; and
c. supplying fluid in surface tension contact with the first opening of said aperture. - View Dependent Claims (18)
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19. In an unpressurized fluid injection system, a fluid droplet ejection device comprising:
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a mechanical member contained at a portion thereof and free to move at another portion thereof and adapted for vibrating motion at its free portion in response to oscillations, said mechanical member having a tapered aperture in its free portion, said aperture having first and second openings, said first opening being larger than said second opening;
an oscillator for imparting mechanical oscillations to said mechanical member in response to an electrical signal; and
an unpressurized source of fluid in fluid communication with said first opening for supplying fluid to said aperture, said fluid continuously adhering to said first opening through a solid/fluid surface interaction.
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20. A method of dispensing a liquid as an atomised spray comprising the steps of maintaining the liquid in contact with a rear surface of a vibratable perforate membrane defining an array of holes, each hole being flared such that the cross-section of each hole narrows in a direction from the rear surface towards a front surface of the membrane, and vibrating the membrane such that droplets of the liquid are dispensed through the flared holes as an atomised spray.
- 21. A method of dispensing a liquid as an atomised spray comprising the steps of maintaining the liquid in contact with a rear surface of a perforate membrane defining an array of holes, each hole being flared such that the cross-section of each hole narrows in a direction from the rear surface towards a front surface of the membrane, said membrane being stiffened by means of a grid of support elements, and said membrane having a sheet defining the array of holes and having thickened portions constituting the support elements, and vibrating said membrane with the grid of support elements and flared holes such that droplets of the liquid are dispensed through the holes as an atomised spray.
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23. Dispensing apparatus for use in dispensing liquid as an atomised spray comprising a vibratable-perforate membrane defining an array of holes and having a front surface and rear surface, liquid supply means for supplying the liquid in contact with the rear surface, and vibrating means operable to vibrate the membrane relative to the liquid supply means such that droplets of the liquid are dispensed through the holes as an atomised spray, wherein each hole is flared such that the cross-section of each hole narrows in a direction from the rear surface towards the front surface.
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24. Dispensing apparatus for use in dispensing liquid as an atomised spray comprising a perforate membrane defining an array of holes and having a front surface and a rear surface, liquid supply means for supplying the liquid in contact with the rear surface, and vibrating means operable to vibrate the membrane such that droplets of the liquid are dispensed through the holes as an atomised spray;
- wherein each hole is flared such that the cross-section of each hole narrows in a direction from the rear surface towards the front surface, wherein the perforate membrane comprises a sheet defining the array of holes through which liquid is dispensed in use and support means supporting the sheet, and wherein said support means comprises a grid of support elements.
- View Dependent Claims (25, 26, 27)
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28. A method of dispensing a liquid as an atomised spray comprising the steps of maintaining the liquid in contact with a rear surface of a vibratable perforate membrane having at least one hole, the hole being flared such that the cross-section of the hole narrows in a direction from the rear surface towards a front surface of the membrane, and vibrating the membrane such that droplets of the liquid-are dispensed through the flared hole as an atomised spray.
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29. Dispensing apparatus for use in dispensing liquid as an atomised spray comprising a vibratable perforate membrane having at least one hole and having a front surface and rear surface, liquid supply means for supplying the liquid to the rear surface, and vibrating means operable to vibrate the membrane relative to the liquid supply means such that droplets of the liquid are dispensed through the hole as an atomised spray, wherein the hole is flared such that the cross-section of the hole narrows in a direction from the rear surface towards the front surface.
Specification