Focused arc beam transducer-reflector

• US 3,965,455 A
• Filed: 04/25/1974
• Issued: 06/22/1976
• Est. Priority Date: 04/25/1974
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Hurwitz, Michael J.
• Primary Examiner(s): Tudor, Harold
• Application Number:
  US05/464,281
• Time in Patent Office: 789 Days
• Field of Search: 343/837, 343/838, 343/840, 343/910, 343/914, 340/8 R, 340/9, 340/10, 340/8 FT, 340/8 L, 340/11, 340/12, 340/13, 310/8, 310/2, 310/8.5, 310/8.6, 310/9.1, 73/67.8 R, 73/67.8 S, 73/71.5 US, 350/294
• US Class Current: 367/151
• CPC Class Codes: G10K 11/28 using reflection, e.g. parabolic reflectors

Abstract

An acoustic transducer-reflector using a single disc-shaped piezoceramic element radiating into a compound reflector for obtaining a line focus sound beam that is characteristic of focused-arc transducers that maybe used for underseas applications and for non-destructive materials testing. The single transducer emits acoustic energy into the compound reflector which reshapes a circular beam into a focused arc beam. A shadow mask or aperture stop positioned in front of the reflector assures a beam such as would be radiated from a ring source.

Claims

1. An acoustic transducer-reflector for simulating a focused-arc beam comprising:

a disc-shaped transducer mounted forward of and concentrically with the transducer-reflector for radiating a beam of acoustic wave energy rearward toward the reflector;

compound reflector means attached behind said disc transducer for producing an emitted wavefront simulating that which would be radiated by a ring source to produce a line focus with great depth of field, said reflector means including a conical reflector concentrically behind said transducer for reflecting the acoustic waves radially outward, and a surface of revolution reflector, made of a truncated parabola for simulating a real-image ring source, concentric with and positioned radially outward from said conical reflector; and

an aperture stop disc with an annular slot positioned forward of and concentric with said surface of revolution reflector and in the focal plane of the real-image ring source.

2. The acoustic transducer-reflector of claim 1 wherein said conical reflector has a half-angle of approximately 50°

.

3. The acoustical transducer-reflector of claim 2 further comprising:

a plurality of struts connecting said transducer to said reflector;

said transducer radiating its beam of acoustic wave energy rearwardly into said conical reflector; and

said aperture stop disc attached to said transducer.