Acoustic suspension system

US4402221A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Mark C. Lee · Poway, US
• Taylor G. Wang · Glendale, US

Key dates

• Filing date: Jun 12, 1981
• Grant date: Sep 6, 1983
• Expiry date: Jun 12, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G10K11/32
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

An acoustic levitation system is described, which can utilize a single acoustic source (12) and a small reflector (14) to stably levitate a small object (16) while the object is processed as by coating or heating it. The system includes a concave acoustic source (12) which has locations on opposite sides of its axis that vibrate towards and away from a focal point (36, FIG. 2) to generate a converging acoustic field. A small reflector (14) is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector can be located about one-half wavelength (L, FIG. 3) from the focal point and can be concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector.