Ultrasonic transducer

• US 4,421,118 A
• Filed: 08/12/1981
• Issued: 12/20/1983
• Est. Priority Date: 08/12/1981
• Status: Expired due to Fees

• Current Assignee: Elscint Limited (Elbit Imaging Limited), Elscint Imaging Incorporated
• Original Assignee: Smith Kline Instruments Incorporated
• Inventors: Meyers, Paul F., Dow, Julian
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US06/292,053
• Time in Patent Office: 860 Days
• Field of Search: 128/660, 128/661, 128/618-620, 310/13-15, 310/17, 310/20, 310/22-24
• US Class Current: 600/446
• CPC Class Codes: G01S 15/8934 using a dynamic transducer configuration
• CPC Class Codes: G10K 11/355 Arcuate movement

Abstract

An ultrasonic transducer is disclosed comprising a transducer head assembly containing a movable crystal holder containing a crystal which is coupled to a stationary base by mechanical linkage means. A motor adapted to provide linear reciprocating motion is coupled to the mechanical linkage means for causing the crystal holder and crystal, when driven by the motor, to undergo reciprocating swinging motion for transmitting ultrasonic energy to and receiving echo signals from an object in front of the transducer in a sector scanning manner.

Claims

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.

2. An ultrasonic transducer as set forth in claim 1, said crystal holder having three pins therein, one centrally disposed pin and two laterally disposed pins, said centrally disposed pin being at the same elevation or at a different elevation from said two laterally disposed pins, said base having three pins therein one centrally disposed pin and two laterally disposed pins said centrally disposed pin being at the same or different elevation as said two laterally disposed pins, said mechanical linkage means comprising:

a pair of links, each link being pivotally connected at their respective ends to respective same sided laterally disposed pins in said crystal holder and said base;

an L-shaped drive bar pivotally connected at one end to the centrally disposed pin in said crystal holder and pivotally mounted at the base of the L to the centrally disposed pin in said base, the other end of said L-shaped bar being coupled to said drive means.

3. An ultrasonic transducer probe as set forth in claim 2, said centrally disposed pin in said base being adapted to flex.

4. An ultrasonic transducer as set forth in claim 1, and further including sensing means for sensing the angular position of said crystal holder.

5. An ultrasonic transducer as set forth in claim 1, said electrical means comprising a power supply for providing an alternating current electrical signal to said electrical coil windings for causing said coil form and stack to undergo relative linear reciprocating motion.

6. An ultrasonic transducer as set forth in claim 1, said electrical means comprising a power supply for providing a direct current electrical signal to said electrical coil windings for causing said coil form and said stack to be displaced relative to each other.

7. An ultrasonic transducer as set forth in claim 1, including a spider guide bonded to one end of said coil form and a multi-pronged two sided spider disposed within said spider guide securely fastened to an end of said non-magnetic case, a first spring disposed between one side of said spider and said non-magnetic case and a second spring disposed on the other side of said spider within said spider guide.

8. An ultrasonic transducer as set forth in claim 1, said transducer being filled with a non-ionic fluid.

9. A motor adapted to impart linear motion comprising:

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 signal for energizing said windings thereby to cause said coil form and stack to undergo linear displacement relative to each other.

10. A motor as set forth in claim 9, said electrical means comprising a power supply for providing an alternating current electrical current signal to said electrical coil windings for causing said coil form and stack to undergo relative linear reciprocating motion.

11. A motor as set forth in claim 9, said electrical means comprising a power supply for providing a direct current electrical current signal to said electrical coil windings for causing said coil form and said stack to be displaced relative to each other.

12. A motor as set forth in claim 9, including a spider guide bonded to one end of said coil form and a multi-pronged two sided spider disposed within said spider guide securely fastened to an end of said non-magnetic case, a first spring disposed between one side of said spider and said non-magnetic case and a second spring disposed on the other side of said spider within said spider guide.