Underwater sound source

Claim 1

A HIGH-POWER UNDERWATER SOUND SOURCE DESIGNATED FOR DEEP SUBMERGENCE AND CAPABLE OF BEING SELECTIVELY CONTROLLED FROM THE SURFACE SO AS TO PRODUCE PULSES OF VARIABLE SPACING AND TIME DURATION AND POSSESSING BROADBAND FREQUENCY CHARACTERISTICS, SAID SOUND SOURCE COMPRISING: A PNEUMATICALLY-OPERATED VIBRATOR DEVELOPING ACOUSTIC ENERGY AND ADAPTED TO OPERATE OVER A GIVEN FREQUENCY BAND; A CHAMBER ENCLOSING SAID VIBRATOR AND TO WHICH THE LATTER IS ATTACHED, SAID CHAMBER HAVING A NATURAL FREQUENCY OF VIBRATION AND BEING PROVIDED WITH AT LEAST ONE APERTURE DESIGNED TO PERMIT THE PASSAGE OF FLUID THERETHROUGH; MEANS FOR OPERATING SAID VIBRATOR AT THE NATURAL FREQUENCY OF VIBRATION OF SAID CHAMBER; WHEREBY SAID CHAMBER IS CAUSED TO RESONATE TO INCREASE THE ACOUSTIC OUTPUT OF SAID SOURCE ABOVE THE HIGHEST LEVEL CAPABLE OF BEING REACHED SOLELY BY OPERATION OF SAID VIBRATOR; A CONTAINER OF PRESSURIZED AIR FORMING PART OF SAID SOUND SOURCE AND SUBMERSIBLE THEREWITH, AND MEANS CONTROLLABLE FROM THE SURFACE, FOR SELECTIVELY ADMITTING AIR FROM SAID CONTAINER TO SAID VIBRATOR TO DETERMINE THE TIME PERIODS DURING WHICH ACOUSTIC ENERGY IS DEVELOPED.