Ultrasonic transducer

Claim 1

An ultrasonic transducer comprising: an elongated handle enclosing a motor adapted to impart linear reciprocating motion, said motor including a plurality of magnets disposed so as to have like magnetic poles of adjacent magnets facing each other; a plurality of iron spacers, each being disposed between adjacent magnets, said magnets and spacers being disposed in a non-magnetic case for forming a stack; a coil form disposed concentrically over said stack of magnets and spacers; a plurality of serially connected oppositely wound electrical coil windings axially disposed along said coil form, each coil being located opposite a respective spacer; a magnetic case disposed concentrically around said stack, coil form and coil windings; means for securing said stack stationary with respect to said magnetic case, and electrical means coupled to said coil windings for providing an electrical current for energizing said windings thereby to cause said coil form and stack to undergo linear displacement relative to each other; a transducer head assembly having an ultrasonic energy transmissive window joined to said handle and enclosing a crystal holder containing a crystal adapted to transmit and receive ultrasonic energy through said window; a stationary base disposed in said head; mechanical linkage means coupling said crystal holder to said base, and drive means coupling said motor to said mechanical linkage means for causing said crystal holder and crystal, when driven by said motor, to undergo reciprocating swinging motion relative to said base for transmitting ultrasonic energy to and receiving echo signals from an object in front of said window in a sector scanning motion.