Underwater acoustic projector

Patent metadata

Field	Value
Publication number	US-9906857-B2
Application number	US-201514689442-A
Country	US
Kind code	B2
Filing date	Apr 17, 2015
Priority date	Apr 17, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

An underwater acoustic projector for projecting acoustic energy through water is described. The acoustic projector includes a housing defining an internal cavity, a plurality of apertures in the housing that place the internal cavity in fluid communication with an external environment, an acoustic baffle disposed in the internal cavity at a first end that fluidly seals the first end of the internal cavity from the external environment, and a projector face that is disposed in the internal cavity at a second end of the internal cavity. The projector face includes a movable piston disposed between outer and inner diaphragms. A magnet is fixed within the internal cavity between the acoustic baffle and the projector face, and a moving coil is connected to the piston and arranged relative to the magnet so as to be driven by the magnet thereby driving the piston.

First claim

What is claimed is:

1. An underwater acoustic projector for projecting acoustic energy through water, comprising:
a housing defining an internal cavity and the housing having a first end and a second end;
a plurality of first apertures through the housing in a portion of the housing that extends from the first end to the second end of the housing, the first apertures being disposed between the first end and the second end of the housing, the first apertures placing the internal cavity in fluid communication with an external environment;
an acoustic baffle disposed in the internal cavity at the first end thereof that fluidly seals the first end of the internal cavity from the external environment;
a projector face disposed in the internal cavity at the second end thereof, the projector face including a movable piston disposed in a space between an outer diaphragm and an inner diaphragm;
a magnet fixed within the internal cavity between the acoustic baffle and the projector face; and
a moving coil connected to the piston, the moving coil is arranged relative to the magnet so as to be driven by the magnet and thereby drive the piston.

2. The underwater acoustic projector according to claim 1 , further comprising:
a liquid provided in the space between the inner diaphragm and the outer diaphragm.

3. The underwater acoustic projector according to claim 2 , wherein the liquid is one of water or oil.

4. The underwater acoustic projector according to claim 1 , further comprising:
one or more second apertures formed in the housing that can place the space between the inner diaphragm and the outer diaphragm in communication with the external environment.

5. The underwater acoustic projector according to claim 4 , further comprising one or more seals for sealing the one or more second apertures.

6. The underwater acoustic projector according to claim 1 , wherein the acoustic baffle includes an acoustic sound absorbing rubber.

7. The underwater acoustic projector according to claim 1 , wherein the first apertures are formed in the housing between the magnet and the acoustic baffle.

8. The underwater acoustic projector according to claim 1 , wherein the inner diaphragm includes an interior surface that faces toward the acoustic baffle and water that enters the housing through the first apertures is in contact with the interior surface and in contact with the acoustic baffle.

9. A method, comprising:
designing the underwater acoustic projector according to claim 1 to permit water to flood the internal cavity of the housing of the underwater acoustic projector when the underwater acoustic projector is submerged in water so that the water equalizes pressure between the internal cavity of the housing and exterior pressure acting on the projector face of the underwater acoustic projector.

10. The method according to claim 9 , further comprising:
designing the underwater acoustic projector to be fixable in a pressure hull, wherein the pressure hull includes part of any underwater body that is fluidly sealed to prevent entry of water.

11. The underwater acoustic projector according to claim 1 , wherein the housing is cylindrical and has a circumference, the first apertures being spaced from one another about the circumference of the housing.

12. A method, comprising:
submerging an underwater acoustic projector in water, the underwater acoustic projector including:
a housing defining an internal cavity and the housing having a first end and a second end;
a plurality of first apertures through the housing in a portion of the housing that extends from the first end to the second end of the housing, the first apertures being disposed between the first end and the second end of the housing, the first apertures placing the internal cavity in fluid communication with an external environment;
an acoustic baffle disposed in the internal cavity at the first end thereof that fluidly seals the first end of the internal cavity from the external environment;
a projector face disposed in the internal cavity at the second end thereof, the projector face including a movable piston disposed in a space between an outer diaphragm and an inner diaphragm; a magnet fixed within the internal cavity between the acoustic baffle and the projector face; and
a moving coil connected to the piston, the moving coil is arranged relative to the magnet so as to be driven by the magnet and thereby drive the piston,

whereby water floods the internal cavity of the housing of the underwater acoustic projector so that the water equalizes pressure between the internal cavity of the housing and exterior pressure acting on the projector face of the underwater acoustic projector.

13. The method according to claim 12 , wherein the underwater acoustic projector is disposed within a pressure hull.

14. The method according to claim 12 , comprising permitting water to flood the space between the inner diaphragm and the outer diaphragm of the underwater acoustic projector.

15. An underwater acoustic projector for projecting acoustic energy through water, comprising:
a housing defining an internal cavity having a first end and a second end;
a plurality of first apertures in the housing that place the internal cavity in fluid communication with an external environment;
an acoustic baffle disposed in the internal cavity at the first end thereof that fluidly seals the first end of the internal cavity from the external environment;
a projector face disposed in the internal cavity at the second end thereof, the projector face including a movable piston disposed in a space between an outer diaphragm and an inner diaphragm;
a magnet fixed within the internal cavity between the acoustic baffle and the projector face;
a moving coil connected to the piston, the moving coil is arranged relative to the magnet so as to be driven by the magnet and thereby drive the piston; and
one or more second apertures formed in the housing that can place the space between the inner diaphragm and the outer diaphragm in communication with the external environment.

16. The underwater acoustic projector according to claim 15 , further comprising one or more seals for sealing the one or more second apertures.

17. An underwater acoustic projector for projecting acoustic energy through water, comprising:
a housing defining an internal cavity having a first end and a second end;
a plurality of first apertures in the housing that place the internal cavity in fluid communication with an external environment;
an acoustic baffle disposed in the internal cavity at the first end thereof that fluidly seals the first end of the internal cavity from the external environment, wherein the acoustic baffle includes an acoustic sound absorbing rubber;
a projector face disposed in the internal cavity at the second end thereof, the projector face including a movable piston disposed in a space between an outer diaphragm and an inner diaphragm;
a magnet fixed within the internal cavity between the acoustic baffle and the projector face; and
a moving coil connected to the piston, the moving coil is arranged relative to the magnet so as to be driven by the magnet and thereby drive the piston.

18. An underwater acoustic projector for projecting acoustic energy through water, comprising:
a housing defining an internal cavity having a first end and a second end;
a plurality of first apertures in the housing that place the internal cavity in fluid communication with an external environment;
an acoustic baffle disposed in the internal cavity a

Assignees

• Lockheed Corp

Inventors

• Sylvia Russell M
• Kelly Patrick J
• Lewis Martin C

Classifications

• G10K9/13

  using electromagnetic driving means · CPC title

• H04R1/44 Primary

  Special adaptations for subaqueous use, e.g. for hydrophone · CPC title