Resonant oscillating antenna drive

Claim 1

AN OSCILLATING ANTENNA DRIVE COMPRISING (A) A FRAME, (B) AN ANTENNA STRUCTURE AND A COUNTERWEIGHT STRUCTURE MOUNTED ON SAID FRAME FOR ROTATIONAL OSCILLATION ABOUT SUBSTANTIALLY PARALLEL AXES OF ROTATION, (C) A PAIR OF SUBSTANTIALLY PARALLEL TORSION BARS FIXEDLY SECURED TO THE ANTENNA AND COUNTERWEIGHT STRUCTURES RESPECTIVELY AND EXTENDING ALONG THE AXES OF ROTATION THEREOF RESPECTIVELY, (D) A COUPLING PLATE FIXEDLY SECURED TO THE PAIR OF TORSION BARS AT THE ENDS THEREOF AWAY FROM THE ANTENNA AND COUNTERWEIGHT STRUCTURES, (E) THE MOMENTS OF INERTIA OF THE ANTENNA AND COUNTERWEIGHT STRUCTURES AND THE TORSIONAL SPRING CONSTANTS OF THE TORSION BARS BEING PREDETERMINED TO ESTABLISH A RESONANT FREQUENCY OF OSCILLATION WITH THE ANTENNA AND COUNTERWEIGHT STRUCTURES OSCILLATING IN COUNTER DIRECTIONS AND THE COUPLING PLATE AT SUBSTANTIALLY A NODE, (F) DRIVING MEANS FOR OSCILLATING THE ANTENNA SUBSTANTIALLY AT SAID RESONANT FREQUENCY, (G) SAID DRIVING MEANS INCLUDING A DRIVING MEMBER OSCILLATING WITH A PREDETERMINED AMPLITUDE OF OSCILLATION AND A SLIP CLUTCH COUPLING SAID DRIVING MEMBER WITH ONE OF SAID ANTENNA AND COUNTERWEIGHT STRUCTURES, (H) THE SLIP CLUTCH BEING DESIGNED AND ADAPTED FOR DRIVING SAID ONE STRUCTURE AT AN OSCILLATION AMPLITUDE CORRESPONDING TO THAT OF SAID DRIVING MEMBER WITH SUBSTANTIALLY NO SLIPPAGE IN NORMAL OPERATION BUT ALLOWING SLIPPAGE FOR SUBSTANTIALLY SMALLER OSCILLATION AMPLITUDES OF SAID ONE STRUCTURE.