Patent US4262227A successfully refreshed from Google Patents.
US4262227A
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US
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Thickness-shear piezo-electric vibrator with additional mass for mode suppression
Assignee: Seikosha KK
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Filing: 1978-11-13
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Granted: 1981-04-14
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Expires: 1998-11-13
Abstract
Abstract A thickness-shear mode piezo-electric vibrator comprises a piezo-electric crystal operable in the thickness-shear mode, driving electrodes formed on opposed surfaces of the crystal, and an addition mass formed on at least one of the driving electrodes and positioned on the nodal line of a 3-fold harmonic vibration so that the frequency f o of the fundamental main vibration and the frequency f 3s of the 3-fold harmonic vibration always satisfy the following relation within the practical application ranges of temperature and load capacitance; ##EQU1## thereby effectively eliminating or preventing the "abnormal frequency phenomenon" which would otherwise occur due to the 3-fold harmonic vibrations.
Inventors
- 👤 Hitoshi Ikeno
- 👤 Tetsuro Konno
- 👤 Mitsuyuki Sugita
- 👤 Hirofumi Yanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:41
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17; H03H9/19; H03H9/02; H03H9/02007; H03H9/02062; H03H9/0207
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
113 words
A thickness-shear mode piezo-electric vibrator comprising: a piezo-electric crystal operable in the thickness-shear mode to vibrate in its fundamental mode, driving electrodes formed on opposed surfaces of said crystal, and an addition mass formed on at least one of said driving electrodes, the improvement wherein said addition mass is suitably positioned on the nodal line of a 3-fold harmonic vibration and on the area where the vibration energy of the fundamental main vibration is sufficiently large so that the frequency f O of the fundamental main vibration and the frequency f 3s of the 3-fold harmonic vibration always satisfy the following relation within the practical application ranges of temperature and load capacitance; ##EQU2##
Claim 2
Dependent Claim
113 words
A thickness-shear mode piezo-electric vibrator comprising: a piezo-electric crystal operable in the thickness-shear mode to vibrate in its fundamental mode, driving electrodes formed on opposed surfaces of said crystal, and an addition mass formed on at least one of said driving electrodes, the improvement wherein said addition mass is suitably positioned on the nodal line of a 3-fold harmonic vibration and on the area where the vibration energy of the fundamental main vibration is sufficiently large so that the frequency f O of the fundamental main vibration and the frequency f 3s of the 3-fold harmonic vibration always satisfy the following relation within the practical application ranges of temperature and load capacitance; ##EQU2##
Claim 3
Dependent Claim
23 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass overlies the entire nodal line of the 3-fold harmonic vibration.
Claim 4
Dependent Claim
26 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass overlies a major portion of the nodal line of the 3-fold harmonic vibration.
Claim 5
Dependent Claim
18 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass consists of a single mass.
Claim 6
Dependent Claim
32 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass comprises two separate masses each each positioned on a portion of the nodal line of the 3-fold harmonic vibration.
Claim 7
Dependent Claim
21 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass has the general shape of an elliptic annulus.
Claim 8
Dependent Claim
31 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said addition mass has the general shape of an elliptic annulus with at least one of its two ends cut off.
Claim 9
Dependent Claim
27 words
A thickness-shear mode piezo-electric vibrator according to claim 1; wherein said piezo-electric crystal is selected from the group consisting of plano-convex type, biconvex type and bevelled type.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |