Fischer & Porter Company

Schlumberger Technology Corporation

Ecole Nationale Superieure De Mecanique Et Des Microtechniques

Pierre Maitre

Jean-Pascal Valentin

Raymond J Besson

Masahiro Kazahaya

Michel Valdois

Richard Delaite

Georges Renard

Jean-Jacques Boy

Daniel Thiebaud

Gerard Genestier

A laser welding technique for joining two parts together, the parts having contacting faces which define an interfacial region. One part is permeable to a laser beam directed toward and focused on the interfacial region, the face of the other part having light-disruptive characteristics whereby when the beam impinges thereon, multiple internal reflections are produced within the interfacial region which trap the energy of the beam to generate sufficient heat to cause the parts to superficially melt and fuse.

Laser welding technique

A differential pressure transducer of the capacitive type responsive to fluid pressure. The transducer includes a cylindrical body having insulating sections at either end provided with a planar end face and a concave cavity surrounded by an annular rim. The cavities communicate with each other through an internal duct in the body and are filled with a dielectric fluid. Covering each cavity and sealed to the surrounding rim is a diaphragm provided with a movable electrode which cooperates with a fixed electrode on the cavity surface to form a capacitor therewith whose value varies as a function of diaphragm deflection in response to an applied pressure. The contour of each cavity is defined by an inner concave portion whose center is aligned with the longitudinal axis of the body and whose periphery merges with an inflection zone, and an outer portion which curves from the inflection zone toward the rim to merge tangentially therewith to avoid a sharp angle at the inner edge of the rim, the inflection zone being about half the distance from the center to the rim.

Differential-pressure transducer

Device for supporting a piezoelectric resonator inside a casing. The device comprises two cross-shaped half-shells, each one comprising: four branches of which the free ends define angle pieces with a horizontal bearing surface of small dimension, which surface is slightly raised with respect to the central part of the corresponding half-shell, as well as one vertical branch holding the edge of the resonator: four identical independent securing flanges to secure the two half-shells in position, said flanges having the shape of a turned down U, each flange comprising, at the end of each branch of the U, two stop elements bearing against two superposed branches of the two half-shells, on the faces of those branches facing said horizontal bearing surfaces; and at least four pairs of springs for suspending the four securing flanges with respect to the casing. The symmetry of the device assembly with respect to three axes perpendicular one to the other, and the shape of the different elements considerably limit the influence of any external radial or axial effects on the resonator.

Device for supporting a piezoelectric resonator inside a casing

In a piezoelectric transducer (10) an external element (12) of tubular form receives a pressure, notably a pressure to be measured, on its external face (16). It is cut in a quartz crystal in one piece with a plate (25) capable of vibrating under the action of an electric stress and extending in a plane parallel to the longitudinal direction of the tubular element inside the latter. Each of the longitudinal edges of the plate is connected by a transverse connecting element (30, 31) to the internal face (14) of the tubular element so as to transmit forces (F1 and F2) resulting from the application of the external pressure to the plate (25) in a direction substantially parallel to its plane and perpendicular to the axis of the tubular element (12).

Piezoelectric pressure and/or temperature transducer

Growing community of inventors

Besancon, France

Pierre Maitre