Ultrasonic motors and converters

• US 4,012,647 A
• Filed: 08/01/1975
• Issued: 03/15/1977
• Est. Priority Date: 01/31/1974
• Status: Expired due to Term

• Current Assignee: Ultrasonic Systems, Inc.
• Original Assignee: Ultrasonic Systems, Inc.
• Inventors: Kuris, Arthur, Balamuth, Lewis, Karatjas, Manuel
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US05/601,046
• Time in Patent Office: 592 Days
• Field of Search: 310/8.1, 310/8.3, 310/8.7, 310/26, 318/116, 318/118
• US Class Current: 310/317
• CPC Class Codes: B06B 1/0261 taken from a transducer or electrode connected to the driving transducer
• CPC Class Codes: B06B 2201/40 with testing, calibrating, safety devices, built-in protection, construction details
• CPC Class Codes: B06B 2201/55 Piezoelectric transducer
• CPC Class Codes: B06B 2201/70 Specific application

Abstract

The invention discloses various embodiments of an ultrasonic motor and converter adapted to be used in home or industrial ultrasonic devices. The ultrasonic motor is generally of a piezoelectric material having a removable tip or of a design in which the complete motor is contained in a housing, which housing has electrical contact means adapted to be plugged into an adapter which, in turn, is connected to a converter. The motor is designed such that frequency sensing means is provided therein and the feedback signal is utilized by the converter to adjust itself thereto. The converter includes tuned circuit means tuned to a band including a desired frequency for sustaining the vibration of said motor at the desired frequency.

Claims

1. A driving circuit for driving an ultrasonic transducer having a piezoelectric element, said transducer being capable of vibration at a plurality of frequencies including a desired frequency, comprising:

A. a power supply for producing a power signal;

B. a reference voltage;

C. a single transistor means having a conductive path coupled intermediate said power supply and a reference voltage and further having a control terminal, a control signal applied to said control terminal controlling the conductivity of said conductive path and therefore controlling the application of said power signal to said piezoelectric element as a driving signal, said conductive path of said transistor means being coupled to said power supply at a junction terminal;

D. transformer means having a primary winding and a secondary winding, said primary winding being electrically coupled intermediate said junction terminal and said piezoelectric element for detecting a detected signal representative at least of the frequency of said driving signal; and

E. tuned circuit means tuned to said desired frequency and formed from inductor means, and capacitor means connected in parallel with said inductor means, said transformer means secondary winding defining said inductor means, said tuned circuit means being operatively coupled between said transistor means control terminal and said reference voltage for applying a control signal to said control terminal for controlling the conductivity of said conductive path at said desired frequency in response to said detected signal to produce said driving signal at said desired frequency.

2. A driving circuit as defined in claim 1, wherein said transistor means includes an emitter, collector, and base, said conductive path being defined by the emitter-collector path of said transistor means, said control terminal being defined by the base of said transistor means.

3. A driving circuit as defined in claim 1, wherein said power supply produces an essentially D.C. power signal

4. A driving circuit as defined in claim 1, wherein said transducer has a desired frequency of vibration at each of load and no-load conditions, said tuned circuit means being tuned to a band of frequencies including both said load and no-load desired frequencies so that the vibration of said transducer is sustained at both load and no-load conditions.

5. An ultrasonic system, comprising:

A. an ultrasonic motor having an output portion for transmission of high frequency mechanical vibrations said motor being capable of vibration at a plurality of frequencies, including a desired frequency;

B. driving circuit means operatively coupled to said ultrasonic motor for applying thereto a driving signal of said desired frequency for sustaining the vibration of said motor at said frequency, said driving circuit means including;

1. a power supply for producing a power signal;

2. a reference voltage;

3. a single transistor means having a conductive path coupled intermediate said power supply and a reference voltage and further having a control terminal, a control signal applied to said control terminal controlling the conductivity of said conductive path and therefore controlling the application of said power signal to said ultrasonic motor as said driving signal, said conductive path of said transistor means being coupled to said power supply at a junction terminal;

C. transformer means having a primary winding and a secondary winding, said primary winding being electrically coupled intermediate said junction terminal and said ultrasonic motor for detecting a detected signal representative at least of the frequency of said driving signal; and

D. tuned circuit means tuned to said desired frequency and formed from inductor means, and capacitor means connected in parallel with said inductor means, said transformer means secondary winding defining said inductor means, said tuned circuit means being operatively coupled between said transistor means control terminal and said reference voltage for applying a control signal to said control terminal for controlling the conductivity of said conductive path at said desired frequency in response to said detected signal to produce said driving signal of said desired frequency.

6. The system as defined in claim 5, wherein said ultrasonic motor includes a piezoelectric transducer means, said transformer primary being electrically connected between said junction terminal and said piezoelectric transducer means.

7. The system as defined in claim 5, wherein said transistor means has an emitter, collector and base, the emitter-collector path of said transistor means defining said conductive path, said base defining said control terminal.

8. The system of claim 5, wherein said power supply includes rectifier means for producing an essentially D.C. power signal.

9. The system as defined in claim 5, wherein said power supply includes a battery for producing a D.C. power signal.

10. The system as defined in claim 5, wherein said tuned circuit means is tuned to a band of frequencies.

11. The system as defined in claim 9, wherein said ultrasonic motor has a desired frequency of vibration at each of load and no-load conditions, said tuned circuit means band of frequencies including both said load and no-load desired frequencies so that the vibration of said motor is sustained at both load and no-load conditions.

12. The system as defined in claim 5, wherein said system includes:

A. adapter means having first electrical and mechanical connector means mounted thereon;

B. cable means for electrically connecting said driving circuit means and said first electrical connector means; and

C. accessory means including;

1. a housing having an outlet opening, said ultrasonic motor being mounted within said housing with the output portion thereof extending through said outlet opening;

2. second electrical and mechanical connector means mounted on said housing and adapted to be releasably connected to said first electrical and mechanical connector means for the mechanical coupling of said housing and adapter means and the transmission of electrical energy therebetween; and

3. means within said housing for electrically connecting said second electrical connector means and said ultrasonic motor.

13. An ultrasonic system as defined in claim 5, including:

A. housing means formed with an outlet opening and a cable aperture, said ultrasonic motor being mounted within said housing means with said output portion extending through said housing means outlet opening, said housing means and ultrasonic motor defining an instrument means adapted to be hand held by the user;

B. cable means passing through said housing means cable aperture and electrically interconnecting said driving circuit means and said ultrasonic motor; and

C. interchangeable means each adapted to be removably secured to the outlet portion of said ultrasonic motor to permit a variety of applications of ultrasonic mechanical vibrations to selected objects for various results.

14. An ultrasonic system as defined in claim 5, including electrical plug means for connection to an electrical outlet, said driving circuit means being mounted in said plug means.

15. The system as defined in claim 5, wherein said ultrasonic motor output portion has a rear section and a front section, said front section having a smaller cross-sectional area than said rear section to act as an acoustical impedance transformer to amplify the mechanical vibrations transmitted to said rear section for transmission by said front section, said ultrasonic motor including support means extending longitudinally from said output portion rear section, said piezoelectric transducer means being positioned on said support means, said ultrasonic motor further including a rear member mounted in telescopic relation to said transducer means on said support means, and locking means for maintaining said output portion, transducer means and rear member under compression.

16. An ultrasonic system, comprising:

A. an ultrasonic motor having an output portion for transmission of high frequency mechanical vibrations, said motor being capable of vibration at a plurality of frequencies including a desired frequency; and

B. driving circuit means operatively coupled to said ultrasonic motor for applying thereto a driving signal of said desired frequency for sustaining the vibration of said motor at said frequency, said driving circuit means including;

1. transistor amplifier circuit means for producing said driving signal having an input and an output;

2. a load circuit operatively coupled to said amplifier circuit means output, said load circuit being free of a tuned circuit and including said ultrasonic motor for the application of said driving signal to said ultrasonic motor;

3. tuned circuit means tuned to said desired frequency for defining a filter means and coupled to said amplifier circuit means input; and

4. sensing means mechanically coupled to said ultrasonic motor for detecting the frequencies of vibration thereof and producing a detected signal representative of the frequencies of vibration of said ultrasonic motor and electrically coupled to said tuned circuit means for applying said detected signal thereto, said tuned circuit means passing only the desired frequency portion of said detected signal to said amplifier circuit means input, said amplifier circuit means amplifying said filtered signal to produce a driving signal of said desired frequency.

17. The system as defined in claim 16, wherein said driving circuit means includes a power supply for producing a power signal;

said amplifier circuit means input controlling the application of said power signal to said ultrasonic motor as said driving signal.

18. The system of claim 16, wherein said power supply includes rectifier means for producing an essentially D.C. power signal.

19. The system as defined in claim 16, wherein said power supply includes a battery for producing a D.C. power signal.

20. The system as defined in claim 16, wherein said tuned circuit means includes capacitor means and inductor means connected in series.

21. The system as defined in claim 16, wherein said driving circuit means includes a power supply operatively coupled to said amplifier means, said power supply including rectifier means for producing an essentially D.C. power signal for said amplifer means.

22. The system as defined in claim 16, wherein said driving circuit means includes a power supply operatively coupled to said amplifier means, said power supply including a battery for supplying a D.C. power signal for said amplifier means.

23. The system as defined in claim 16, wherein said amplifer means includes transistor means having an emitter, collector, and base, said tuned circuit means being operatively coupled to said base, said driving circuit means including a power supply and connecting circuit means operatively connecting said power supply, the emitter-collector path of said transistor means and said load circuit.

24. The system as defined in claim 16, wherein said sensing means is a piezoelectric sensing member mechanically coupled to said motor output portion.

25. The system as defined in claim 24, wherein said ultrasonic motor includes a piezoelectric transducer means electrically connected to said driving circuit means for receiving said driving signal therefrom.

26. The system as defined in claim 25, wherein said motor output portion has a rear section and a front section, said front section having a smaller cross-sectional area than said rear section to act as an acoustical impedance transformer to amplify the mechanical vibrations applied thereto for transmission by said front section, said ultrasonic motor including support means extending longitudinally from said rear section, said piezoelectric transducer means being positioned on said support means, said ultrasonic motor further including a rear member mounted in telescopic relation to said transducer means and locking means for maintaining said output portion, said transducer means and said rear member being under compression.

27. The system as defined in claim 26, wherein said piezoelectric sensing member is mounted in telescopic relation to said rear member on said support means, said locking means maintaining said output portion, transducer means, sensing member and rear member under compression.

28. The system as defined in claim 16, wherein said ultrasonic motor includes a piezoelectric transducer means having sensing electrodes and driving electrodes, said driving electrodes being connected to said driving circuit means for receiving said driving signal therefrom, said sensing electrodes defining said sensing means.

29. The system as defined in claim 16, wherein said tuned circuit means is tuned to a band of frequencies.

30. The system as defined in claim 24, wherein said ultrasonic motor has a desired frequency of vibration at each of load and no-load conditions, said tuned circuit means band of frequencies including both said load and no-load desired frequencies so that the vibration of said motor is sustained at both load and no-load conditions.

31. The system as defined in claim 16, wherein said system includes:

A. adapter means having first electrical and mechanical connector means mounted thereon;

B. cable means for electrically connecting said driving circuit means and said first electrical connector means; and

C. accessory means including;

1. a housing having an outlet opening, said ultrasonic motor being mounted within said housing with the output portion thereof extending through said outlet opening;

2. second electrical and mechanical connector means mounted on said housing and adapted to be releasably connected to said first electrical and mechanical connector means for the mechanical coupling of said housing and adapter means and the transmission of electrical energy therebetween; and

3. means within said housing for electrically connecting said second electrical connector means and said ultrasonic motor.

32. An ultrasonic system as defined in claim 16, including:

A. housing means formed with an outlet opening and a cable aperture, said ultrasonic motor being mounted within said housing means with said output portion extending through said housing means outlet opening, said housing means and ultrasonic motor defining an instrument means adapted to be hand held by the user;

B. cable means passing through said housing means cable aperture and electrically interconnecting said driving circuit means and said ultrasonic motor; and

C. interchangeable means each adapted to be removably secured to the outlet portion of said ultrasonic motor to permit a variety of applications of ultrasonic mechanical vibrations to selected objects for various results.

33. An ultrasonic system as defined in claim 16, including electrical plug means for connection to an electrical outlet, said driving circuit means being mounted in said plug means.

34. A driving circuit for driving an ultrasonic transducer having a piezoelectric element, said transducer being capable of vibration at a plurality of frequencies including a desired frequency comprising:

A. sensing means mechanically coupled to said ultrasonic transducer for detecting the frequencies of vibration thereof and producing a detected signal representative of said frequencies of vibration;

B. transistor amplifier means having an input and an output;

C. tuned circuit means tuned to said desired frequency and electrically connected intermediate said sensing means and said amplifier means input, said tuned circuit means being adapted to filter said detected signal and pass to said amplifier means input the component of said detected signal of said desired frequency; and

D. load circuit means free of a tuned circuit operatively connecting said amplifier means output and said piezoelectric element for applying a driving signal to said piezoelectric element of said desired frequency.

35. The driving circuit as defined in claim 34, wherein said tuned circuit means includes capacitor means and inductor means connected in series, said sensing means being a piezoelectric sensing member mechanically coupled to said ultrasonic transducer.

36. A driving circuit as defined in claim 34, wherein said transducer has a desired frequency of vibration at each of load and no-load conditions, said tuned circuit means being tuned to a band of frequencies including both said load and no-load desired frequencies so that the vibration of said motor is sustained at both load and no-load conditions.

37. A driving circuit for driving an ultrasonic transducer having a piezoelectric element, said transducer being capable of vibration at a plurality of frequencies including a desired frequency comprising:

A. sensing means mechanically coupled to said ultrasonic transducer for detecting the frequencies of vibration thereof and producing a detected signal representative of said frequencies of vibration;

B. amplifier means including a transistor means having a conductive path and a control terminal, the signal applied to said control terminal being amplified in said conductive path;

C. tuned circuit means tuned to said desired frequency and electrically connected intermediate said sensing means and said transistor means control terminal, said tuned circuit means being adapted to filter said detected signal and pass to said transistor means control terminal the component of the detected signal of said desired frequency for amplification by said transistor means;

D. a power supply; and

E. load circuit means free of a tuned circuit operatively connecting said transistor means conductive path and said piezoelectric element for applying a driving signal to said piezoelectric element of said desired frequency, said load circuit means including a transformer having a primary winding connected in series with said power supply and said transistor means conductive path and a secondary winding electrically connected to said piezoelectric element, whereby the amplified component of said detected signal of said desired frequency is applied as a driving signal to said piezoelectric element.

38. An ultrasonic system, comprising:

A. an ultrasonic motor having an output portion for transmission of high frequency mechanical vibrations, said motor being capable of vibration at a plurality of frequencies including a desired frequency; and

B. driving circuit means operatively coupled to said ultrasonic motor for applying thereto a driving signal of said desired frequency for sustaining the vibration of said motor at said frequency, said driving circuit means including;

1. amplifier circuit means having a transistor means including a conductive path and a control electrode;

2. sensing means mechanically coupled to said ultrasonic motor for detecting the frequencies of vibration thereof and producing a detected signal representative of the frequencies of vibration of said ultrasonic motor;

3. tuned circuit means tuned to said desired frequency and electrically connected intermediate said sensing means and said transistor means control electrode, said tuned circuit means being adapted to filter said detected signal and pass to said transistor means control electrode the component of said detected signal of said desired frequency, said transistor means amplifying said detected signal, the amplified detected signal appearing in said conductive path;

4. a power supply for supplying a power signal; and

5. load circuit means free of a tuned circuit operatively connecting said transistor means conductive path, power supply, and said ultrasonic motor including a transformer having a primary winding electrically connected in series with said power supply and said transistor means conductive path and a secondary winding electrically connected to said ultrasonic motor, whereby said motor is driven by said amplified detected signal.