Abstract: The electron gun comprises an ionization chamber, adjacent to a high voltage chamber. In the wall common the both chambers provision is made for an extraction grid. On the opposite side, the ionization chamber comprises an outlet window for the electrons similar in shape to the extraction grid, and accompanied by a fine metallic foil. The high voltage chamber comprises a cathode brought to a high negative voltage. By giving the two grids the shape of similar parallel strips, a masking effect and a focusing effect are obtained at one and the same time which allows the efficiency of the electron gun to be increased.

Abstract: A high-torque high-ratio transmission comprises a housing provided with a rigid annular surface with teeth juxtaposed with the teeth of a flexible element connected to a slow shaft. The fast shaft has a flange provided with a groove of varying depth in which an array of balls is guided, the balls pressing the flexible element against the housing crown of teeth as the rapid shaft is rotated. The flange of the rapid shaft can be braced by another set of balls on the opposite side thereof.

Abstract: Vehicle able to move by adhesion on a random surface, with a central body defining a pivoting axis which remains substantially perpendicular to a surface and which has two groups of central supports which adhere to the surface; first and second carriages, each provided with two groups of adhesive end supports; first and second members for the guidance in rectilinear translation and without rotation of the first and second carriages in accordance with two directions which remain substantially orthogonal to the pivoting axis. The first and second carriages are displaceable along the guidance members; the first and second guidance members are pivotal about the pivot axis and the groups of central supports are rotatable about the pivot axis.

Abstract: Device for the injection of a gas in a liquid, constituted by a gas feed tube in which at least a part of the walls is immersed in the liquid at the place where the injecting of the said gas is to be effected, flexible pipes having a small inside diameter being connected up along the said walls, the gas escaping in the form of bubbles from their free ends in the liquid.

Abstract: A device for bubbling gas into a liquid; means are provided at the point of exit of the bubbles from the device to provide a liquid flow that sweeps the bubbles into the liquid, thereby provoking early detachment of the bubbles from the device.

Abstract: A method and apparatus for producing a very fast succession of identical well-defined drops, driven at very high speed, in which a jet of liquid which is divided into droplets by high-frequency vibration is produced at very high speed.