Abstract: Spherical balls, notably microballs of welding alloys, are produced by passing a melted material through vibrating orifices of a granulation pot, in order to form droplets which solidify when falling, by gravity, into a cooling tower filled with an inert gas. To improve the surface condition of the balls, the inert gas comprises approximately 15 to 150 ppm of oxygen. Moreover, the melted material is subject to ultrasound stirring just before being fed into the granulation pot. The balls are, preferably, dampened at the outlet of the cooling tower by brushes composed of polyamide wires. Besides, the control of the vibration frequency of the vibrating orifices in relation to the percentage of balls meeting the standards enables to improve the output.

Abstract: Spherical balls, notably microballs of welding alloys, are produced by passing a melted material through vibrating orifices of a granulation pot, in order to form droplets which solidify when falling, by gravity, into a cooling tower filled with an inert gas. To improve the surface condition of the balls, the inert gas comprises approximately 15 to 150 ppm of oxygen. Moreover, the melted material is subject to ultrasound stirring just before being fed into the granulation pot. The balls are, preferably, dampened at the outlet of the cooling tower by brushes composed of polyamide wires. Besides, the control of the vibration frequency of the vibrating orifices in relation to the percentage of balls meeting the standards enables to improve the output.

Abstract: An automatically controlled cleaning device (14) for removing visibility-impairing foreign matter, e.g. rain, snow or mud, from the surface of a window such as a motor vehicle windscreen (8). The device uses a sensor such as an ultrasonic transducer (12a, 12b) in which the frequency (f) and the spacing (d) between the transmitter (12a) and the receiver (12b) enable the presence of foreign matter to be detected simply by measuring the phase difference between the transmitted signal and the received signal. This device may be used in automatic wiper systems or the like.

Abstract: An ultrasonic device for the continuous production of microdroplets of uniform particle size distribution. This device comprises a vibrating surface (11) which, by its orthogonal ultrasonic vibratory mode, atomizes a material in the liquid state brought up from the interior of the device by means (20,22,24) comprising an intermediate flow-regulating and/or heat-regulating chamber (22) subjacent the vibrating surface (11).

Abstract: A method of comparing a handwriting with a reference writing by the measurement of signals V.sub.x and V.sub.y characteristic of the speed components along the abscissa and ordinate respectively of a rectangular co-ordinate system. Each speed signal V.sub.x and V.sub.y of the handwriting and the reference writing are divided into discreet time segments of the movements which produced the writing, the position of each such segment of the writing being coordinated with the corresponding segments of the movement of the reference writing, and determining a correction factor which is dependent upon the time variation between each movement segment of the handwriting and the corresponding movement segment of the reference writing.

Abstract: A method for storing compressed data indicative of an analog signal and reproducing that analog signal from the compressed data. The analog signal to be stored is superimposed on a rectangular coordinate system. An elementary interval is defined on the X-axis of an X-Y coordinate system for the selection of a first series of points, a second series of points (R.sub.1, R.sub.2, R.sub.3) is determined by establishing a threshold ratio between the chord (C.sub.1, C.sub.1 ') separating two non-consecutive points and the sum of the chords (C.sub.1, C.sub.2, C.sub.3 ; C.sub.1 ', C.sub.2 ', C.sub.3 ') separating each of the consecutive points within two non-consecutive points. An interval (N) between these two non-consecutive points is selected to correspond to the maximum ratio below this threshold.

Abstract: The disclosed device comprises electric conductors (1, 1'; 2') arranged under the writing surface and associated to a writing implement provided with a permanent magnet of which the power supply is orientated in parallel to its longitudinal axis. Said conductors form elongated meandres-like windings covering the writing surface so that when the implement is displaced in parallel to said surface and tranversely to the meandres of the windings, a sinusoidal voltage is induced at the terminals of the windings provided the instrument is close enough to the writing surface. The pitch of the meandres of the windings is so elected as to induce a sinusoidal voltage having an amplitude higher than a given threshold for a predetermined interval between the writing implement and the writing surface.

Abstract: This device comprises two pairs of superimposed pick-up coils 1, 2, 5, 6. Each pair is formed by two windings coupled in series but with opposing winding directions, each winding of one pair having a layer of rectilinear conductive portions 1a, 2a, 5a, 6a side by side parallel to and superimposed on the similar portions of the other winding. These two windings extend on either side of their superimposed layers respectively. The superimposed layers of one pair of windings are orthogonal to those of the other pair.This arrangement is intended to induce in each pair of coils, under the influence of a permanent magnet having a flux approximately perpendicular to these windings, fluxes which add up when the inductive flux varies in a plane parallel to the coils and which are cancelled when the inductive flux varies perpendicularly to this plane.

Abstract: The sensor element of this device comprises at least two electrical conductor windings (E.sub.x) and (E.sub.y) which are superposed. Each of these windings is shaped so as to have a rectilinear portion over at least one portion of its length and the windings are disposed so that two of their respective rectilinear portions are superposed and so that the conductors of one of these portions are at right angles to the conductors of the other portion. The area covered by these two windings constitutes the surface in which the sensor element of the device may register, at the terminals of the two windings (E.sub.x) and (E.sub.y), voltages (U.sub.y) and (U.sub.y) as a function of the magnetic field variations following the displacement of a permanent magnet rigid with the writing instrument. The signals resulting from this device may be used to identify a signature, or to transmit written characters.