Research/Patents/US 4939702
US 4939702

BARRIER SONAR

Assignee

Filed

Jul 19, 1968

Granted

Jul 3, 1990

Location

Abstract

An electronic barrier utilizes a bifurcated beam of wave energy to establ a barrier area having a null between the forks thereof. Objects encroaching on said beam cause a portion thereof to be scattered in the foreward direction. Suitable receiver equipment located remote from the source of the bifurcated beam and responsive to the foreward scattered beam is connected to provide an indication of said encroachment.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Jan 22, 1982

Rescinded

Mar 15, 1990

Duration

8 years, 1 month

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records