US3787743A - Flexion mode crystalline bar for an oscillator - Google Patents

Flexion mode crystalline bar for an oscillator Download PDF

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Publication number
US3787743A
US3787743A US00224704A US3787743DA US3787743A US 3787743 A US3787743 A US 3787743A US 00224704 A US00224704 A US 00224704A US 3787743D A US3787743D A US 3787743DA US 3787743 A US3787743 A US 3787743A
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United States
Prior art keywords
pair
bar
faces
plane
flexion
Prior art date
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Expired - Lifetime
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US00224704A
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English (en)
Inventor
G Gibert
P Vidal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Compagnie Electronique et de Piezoelectricite CEPE
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Compagnie Electronique et de Piezoelectricite CEPE
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/0504—Holders; Supports for bulk acoustic wave devices
    • H03H9/0533—Holders; Supports for bulk acoustic wave devices consisting of wire

Definitions

  • the crystal elements used take the form of elongated bars whose section is nearsquare, equipped with electrodes whose shape and disposition are such that the resultant vibrations involve a bending or flexion of the bar.
  • Bars equipped with fixings designed in accordance with the invention have exhibited improved characteristics of operation compared with the prior art ones.
  • the present invention overcomes these drawbacks, by cutting the crystal bars following new external contours, taking into account the anisotropy of the material of which they are made.
  • the invention relates to an oscillatory bar of parallelepiped form capable of mechanical oscillations in a flexion mode in one plane, said bar comprising two pairs of faces parallel to its longitudinal axis of symmetry, the first pair being perpendicular to said flexion plane and the second parallel thereto, and a pair of terminal faces limited by external straight contour lines, wherein said contour lines contained in the first pair of faces, make an angle ranging between 0 and 60 with a straight line perpendicular to said second pair of faces.
  • FIG. 1 illustrates a prior art crystal bar
  • FIG. 2 illustrates a first embodiment of a crystal bar in accordance with the invention
  • FIG. 3 illustrates a second embodiment of a crystal bar in accordance with the invention.
  • FIG. 1 illustrates a crystal bar, fixed in a partially illustrated support, designed to operate in the flexion mode, said bar being of a conventional kind.
  • the crystallographic axes X, Y and Z being respectively the electric, mechanical and optical axes
  • the bar is equipped with fixing devices 4 and 5 the locations of whose points of attachment to the fixing faces, e.g., at 10, are chosen in accordance with French Patent No. PV 71 05,751 dated Feb.
  • the straight line D is on the other hand contained in a plane P perpendicular to the fixing faces and containing the point M the straight lines of intersection with these faces can be considered as lines of minimum vibration,upon which there can be freely selected, in the manner hereinbefore described, the locations of the points of attachment of the device used to fix the crystal.
  • FIG. 2 illustrates a first embodiment of the oscillating bar in accordance with the invention.
  • This angle the value ranges between and 45 depends upon the ratio between the thickness 2 and the width w of the bar, and is measured in the reverse direction, namely the clockwise direction.
  • the determination of this angle has been based upon theoretical considerations checked by practical trials, from considerations similar to that which have led to the adoption of new positions for the fixing points, this explaining why in both cases, the senses of the angles alpha relating to the straight lines linking the pairs of points, and the senses of the angles gamma relating to the terminal faces, are the same.
  • FIG. 3 illustrates a second embodiment of an oscillatory crystal bar in accordance with the invention. It exhibits the same general geometric features as that of FIG. 2, but the terminal faces planes have additionally been rotated through an angle delta about the axis Z.
  • This angle whose value ranges between 0 and 60", is measured in the plane parallel to the plane X Y in the reverse direction, namely the clockwise direction.
  • This rotation angle tends, in the crystal, to make the directions of the terminal faces and those of the lines of minimum vibration of the crystal, already referred to, to approach one another, in magnitude and direction,thus satisfying over the whole external surface, the limit conditions characterising a given mode of vibration in an anisotropic medium.
  • a quartz crystal bar, cut in accordance with the invention having a length of 47 mm, a thickness of 2.4 mm and a width of 1.6 mm, with termina] faces having gamma and delta angles of 1 l and 40 respectively had an aging rate four times less than that exhibited by a crystal bar cut in accordance with the prior art.
  • a crystalline bar of parallelepiped form capable of piezoelectric oscillations in a plane, in a flexion mode, comprising two pairs of faces parallel to its longitudinal axis of symmetry, the first pair being perpendicular to said plane, and the second parallel thereto, and one pair of terminal faces limited by external straight contour lines, said second pair including the fixing points for attaching at zones of minimum flexion vibration one of the ends of bar suspension wires respectively attached by their other end to a support, each of said pairs being equipped with a pair of plane electrodes, each pair of electrodes being respectively connected to one of the two terminals of an alternative voltage source, wherein those of said straight contour lines contained in the first pair of faces make an angle of between 0 and 45 with a direction perpendicular to said second pair of faces, counted in a clockwise direction.
  • a crystal oscillator comprising a crystalline bar as claimed in claim 1.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
US00224704A 1971-02-26 1972-02-09 Flexion mode crystalline bar for an oscillator Expired - Lifetime US3787743A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7106696A FR2127185A5 (ja) 1971-02-26 1971-02-26

Publications (1)

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US3787743A true US3787743A (en) 1974-01-22

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US00224704A Expired - Lifetime US3787743A (en) 1971-02-26 1972-02-09 Flexion mode crystalline bar for an oscillator

Country Status (6)

Country Link
US (1) US3787743A (ja)
CH (2) CH157872A4 (ja)
DE (1) DE2209101A1 (ja)
FR (1) FR2127185A5 (ja)
GB (1) GB1386822A (ja)
IT (1) IT947879B (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267479A (en) * 1977-09-16 1981-05-12 Citizen Watch Co., Ltd. Mounting clips for thickness shear piezoelectric oscillator
EP1445858A1 (en) * 2003-02-04 2004-08-11 Nihon Dempa Kogyo, Co., Ltd. Piezoelectric crystal material and piezoelectric resonator

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485722A (en) * 1945-01-31 1949-10-25 Gen Motors Corp Crystal
US2925502A (en) * 1956-12-21 1960-02-16 Philips Corp Piezo-electric quartz crystal of elongated shape
US3311854A (en) * 1962-06-13 1967-03-28 Bell Telephone Labor Inc Single crystal quartz filter elements, transducers and delay lines

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485722A (en) * 1945-01-31 1949-10-25 Gen Motors Corp Crystal
US2925502A (en) * 1956-12-21 1960-02-16 Philips Corp Piezo-electric quartz crystal of elongated shape
US3311854A (en) * 1962-06-13 1967-03-28 Bell Telephone Labor Inc Single crystal quartz filter elements, transducers and delay lines

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267479A (en) * 1977-09-16 1981-05-12 Citizen Watch Co., Ltd. Mounting clips for thickness shear piezoelectric oscillator
EP1445858A1 (en) * 2003-02-04 2004-08-11 Nihon Dempa Kogyo, Co., Ltd. Piezoelectric crystal material and piezoelectric resonator
US20040155305A1 (en) * 2003-02-04 2004-08-12 Nihon Dempa Kogyo Co., Ltd. Piezoelectric crystal material and piezoelectric resonator
US6924588B2 (en) 2003-02-04 2005-08-02 Nihon Dempa Kogyo Co., Ltd. Piezoelectric crystal material and piezoelectric resonator

Also Published As

Publication number Publication date
GB1386822A (en) 1975-03-12
IT947879B (it) 1973-05-30
CH560926B5 (ja) 1975-04-15
FR2127185A5 (ja) 1972-10-13
CH157872A4 (ja) 1974-11-15
DE2209101A1 (de) 1972-09-07

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