Showing papers on "Bimorph published in 1967"

Transducer having spaced apart oppositely flexing piezoelectric members

Abstract: AN ELECTROACOUSTIC TRANSDUCER HAVING PIEZOELECTRIC DRIVING MEANS CONSISTING OF FIRST AND SECOND SPACED APART BIMORPHS HAVING A CENTRAL PORTION AND AN EDGE PORTION. A SPACER COUPLES THE SAME PORTION OF EACH BIMORPH TOGETHER. THE OTHER PORTION OF EACH BIMORPH IS COUPLED RESPECTIVELY TO SUPPORT MEANS AND A DIAPHRAGM. THE BMORPHS ARE ELECTRICALLY INTERCONNECTED SO THAT THEY FLEX IN OPPOSITE DIRECTIONS. A FURTHER EMBODIMENT INCLUDES THIRD AND FOURTH SPACED APART BIMORPHS OPERATING SIMILAR TO AND DIRECTLY ATTACHED TO THE FIRST AND SECOND BIMORPHS.

Improvements in electric relays

Abstract: 1,096,824. Piezo-electric and electro-strictive relays. PLESSEY-UK Ltd. March 17, 1965 [March 26, 1964], No. 12971/64. Heading H2B. A relay comprises a piezo-electric or electrostrictive member 12 carrying a contact or contacts 15 engageable with a contact or contacts 16 on body 11 according to the polarity of the voltage applied at electrodes 13, variable magnetic biasing being provided by a magnet 20 attracting an armature 14 on member 12, Fig. 1, or a magnetic element 21 included in the member 12, Fig. 4. A U-shaped magnet 20 holds member 12 in either contactmaking position and also provides for snapactuation of the contacts. Magnet 20 is slidably mounted, Fig. 4, to vary the magnetic interaction between the barium ferrite magnet 20 and the steel shim 21 in the bimorph element or member 12. Bimorph 12 is of lead zirconate titanate strips which have been polarized.

Improved method of making bimorph elements

Abstract: 1,097,013. Piezoelectric transducers. PLESSEY-U.K. Ltd. March 17, 1965 [March 26, 1964], No. 12970/64. Heading H1E. In the manufacture of a bimorph element having thin strips of a permanently polarizable material having piezoelectric or electroatrictive properties carried on opposite faces of a thin metallic support member, the strips are polarized before being fixed to the support member. A sheet of lead zirconate titanate ceramic material is coated on each face with silver and baked, and polarized by applying a voltage between electrodes secured to the two silver layers while the sheet is immersed in liquid paraffin at 140‹ C. The sheet is cleaned and cut into strips, and silver conductive cement applied to the positive face of one strip and the negative face of another, whereafter a shim of brass is sandwiched between the two cemented faces and the composite assembly is cured by heating under pressure. Alternatively, two sheets of polarized material may be cemented to the opposite faces of a brass sheet and cured prior to cutting the composite assembly into separate bimorph elements.

Bidirectional Detector of Ultrasonic Particle Motion in Solids

Abstract: A compact bidirectional detector of ultrasonic particle motion in solids has been developed and used in connection with a three‐dimensional seismic model study. It comprises a matched pair of bimorph crystals and sum and differencing circuits to separate vertical and horizontal motions. The ability of the apparatus to display motion trajectories similar to those predicted by theory is demonstrated.