Abstract: An acoustical lens for focusing ultrasonic energy having a transducer, a curved focussing lens and a voltage generator coupled with the transducer. The transducer is comprised of an array of piezoelectric crystal elements. The focussing lens has a concave upper surface and a planar bottom surface allowing the array of piezoelectric elements to be coupled to the bottom surface of the array. The piezoelectric elements receive voltage from the voltage generator and transmit an energy ray through the focussing lens producing a focussed energy beam.

Abstract: An acoustical lens for focusing ultrasonic energy having a transducer, a curved focussing lens and a voltage generator coupled with the transducer. The transducer is comprised of an array of piezoelectric crystal elements. The focussing lens has a concave upper surface and a planar bottom surface allowing the array of piezoelectric elements to be coupled to the bottomsurface of the array. The piezoelectric elements receive voltage from the voltage generator and transmit an energy ray through the focussing lens producing a focussed energy beam.

Abstract: An eyeglass retainer is provided for holding eyeglasses afloat in the event the eyeglasses accidentally fall into a body of water. The eyeglass retainer is comprised of an elongated, water impervious, resilient hollow flexible tube having open ends which grip the bows of an eyeglass frame and a float in the form of an open celled plastic block having a pair of parallel openings therethrough. The flexible tube is threaded through the openings prior to attachment of the ends of the tube to the eyeglass bows. The block has a buoyancy greater than the weight of the eyeglasses to thereby hold the eyeglasses close to the surface of a body of water.