Compass direction indicating system

Claim 1

A SYSTEM FOR INDICATING THE ANGULAR RELATIONSHIP OF A ROTATABLE DIRECTIONAL SONOBUOY HYDROPHONE WITH RESPECT TO MAGNETIC NORTH COMPRISING: A ROTATABLE CYLINDRICAL HOUSING HAVING A VERTICALLY SPACED LIGHT SOURCE AND PHOTODIODE MEANS SECURED THERETO, SAID HOUSING INCLUDING UPPER AND LOWER END MEMBERS AND BEING FILLED WITH DAMPING FLUID, A CENTRALLY DISPOSED INDENTATION FORMED ON THE INTERIOR SURFACE ON EACH OF SAID END MEMBERS, SAID INDENTATIONS BEING IN VERTICAL ALIGNMENT, A HYDROPHONE FIXEDLY SECURED WITH RESPECT TO SAID CYLINDRICAL HOUSING, A COMPASS ASSEMBLY WITHIN SAID HOUSING INCLUDING A ROTATABLE SHAFT, HAVING THE ENDS THEREOF LOOSELY SEATED IN SAID INDENTATION, A RING MAGNET COAXIALLY DISPOSED ABOUT AND RIGIDLY SECURED TO SAID SHAFT, AND A DISC MEMBER RIGIDLY SECURED TO SAID SHAFT BETWEEN SAID LIGHT SOURCE AND SAID PHOTODIODE MEANS, SAID DISC MEMBER INCLUDING A UNIFORMLY TAPERING WINDOW MEANS FOR VARIABLY IMPENDING THE QUANTITY OF LIGHT DIRECTED TOWARD SAID PHOTODIODE, THE CENTER LINE OF SAID TAPERING WINDOW BEING RADIALLY EQUIDISTANT FROM THE CENTRAL AXIS OF SAID SHAFT, SAID PHOTODIODE MEANS HAVING A RESISTANCE WHICH VARIES LINEARLY AS A FUNCTION OF THE LIGHT TRANSMITTED THROUGH SAID WINDOW; WHEREBY THE QUANTITY OF LIGHT RECEIVED BY SAID PHOTODIODE IS INDICATIVE OF THE ANGULAR RELATIONSHIP OF THE HYDROPHONE AND MAGNETIC NORTH, AND CIRCUIT MEANS CONNECTED TO SAID PHOTODIODE MEANS PROVIDING AN OUTPUT PULSE HAVING A DURATION PROPORTIONAL TO SAID LIGHT INTENSITY.

Claim 2

A SYSTEM FOR INDICATING THE ANGULAR RELATIONSHIP OF A ROTATABLE DIRECTIONAL SONOBUOY HYDROPHONE WITH RESPECT TO MAGNETIC NORTH COMPRISING: A ROTATABLE CYLINDRICAL HOUSING HAVING A VERTICALLY SPACED LIGHT SOURCE AND PHOTODIODE MEANS SECURED THERETO, SAID HOUSING INCLUDING UPPER AND LOWER END MEMBERS AND BEING FILLED WITH DAMPING FLUID, A CENTRALLY DISPOSED INDENTATION FORMED ON THE INTERIOR SURFACE ON EACH OF SAID END MEMBERS, SAID INDENTATIONS BEING IN VERTICAL ALIGNMENT, A HYDROPHONE FIXEDLY SECURED WITH RESPECT TO SAID CYLINDRICAL HOUSING, A COMPASS ASSEMBLY WITHIN SAID HOUSING INCLUDING A ROTATABLE SHAFT, HAVING THE ENDS THEREOF LOOSELY SEATED IN SAID INDENTATION, A RING MAGNET COAXIALLY DISPOSED ABOUT AND RIGIDLY SECURED TO SAID SHAFT, AND A DISC MEMBER RIGIDLY SECURED TO SAID SHAFT BETWEEN SAID LIGHT SOURCE AND SAID PHOTODIODE MEANS, SAID DISC MEMBER INCLUDING A UNIFORMLY TAPERING WINDOW MEANS FOR VARIABLY IMPENDING THE QUANTITY OF LIGHT DIRECTED TOWARD SAID PHOTODIODE, THE CENTER LINE OF SAID TAPERING WINDOW BEING RADIALLY EQUIDISTANT FROM THE CENTRAL AXIS OF SAID SHAFT, SAID PHOTODIODE MEANS HAVING A RESISTANCE WHICH VARIES LINEARLY AS A FUNCTION OF THE LIGHT TRANSMITTED THROUGH SAID WINDOW; WHEREBY THE QUANTITY OF LIGHT RECEIVED BY SAID PHOTODIODE IS INDICATIVE OF THE ANGULAR RELATIONSHIP OF THE HYDROPHONE AND MAGNETIC NORTH, AND CIRCUIT MEANS CONNECTED TO SAID PHOTODIODE MEANS PROVIDING AN OUTPUT PULSE HAVING A DURATION PROPORTIONAL TO SAID LIGHT INTENSITY.