Abstract: A process for glueing together two non-metallic substrates with a hot polymerizable adhesive wherein a ferromagnetic or ferrimagnetic filler material is distributed within the substrate and/or adhesive and the combination is subjected to induction heating by means of a magnetic field. The filler comprises particles having a defined size range, resistivity, coercive field and induced magnetic field such that the sum of the Foucault current losses and hysteresis losser permit the filler to provide power of 1000 to 10,000 W/cm.sup.3. The heating temperature is limited to about the maximum temperature of polymerization of the adhesive by fixing its duration to less than 60 seconds whereby the temperature of the adhesive/substrate interface is at least the minimum polymerization temperature.

Abstract: An elongated substrate made of an electric insulating material carries an elongated conductive track made of aluminium which has a constriction in its centre part in order to increase the heating of the said centre part with a view to reducing as much as possible the volume of material to melt. The ends of the track each comprise an annular part which partially covers a nickel or aluminium pad. The connection and cooling of the ends is carried out by connection brackets. This fuse is calculated in such a way that for a rated current IN, a maximum temperature variation .DELTA.T and a length of the electric conductor designated 2b, thermal equilibrium is obtained when the relationship between the cross section S of the said conductor and that S' of the base material corresponds approximately to:S=.rho.'.sub.th..rho..sub.e.b.sup.2.IN.sup.2 /2S'..DELTA.Tmaxwhere .rho.'.sub.th is the thermal resistivity of the substrate and .rho..sub.e the electrical resistivity of the conductive track.

Abstract: A pulse of current of several hundreds of volts is established between two electrodes immersed in a resistive liquid. By concentration of the current at the end of one electrode, which is bonded onto an insulating support, a volume of liquid in contact with the end of this electrode is vaporised, causing an abrupt drop in current. Because of the voltage of the pulse, which is several hundred volts, a greater current re-establishes itself immediately across the volume of vaporised liquid, as a result of a sort of ionization of the vapor, causing superheating and energy sufficient to expel a droplet of liquid through an opening provided in a membrane. In order to limit the energy of the superheating phase and control the size of the droplets, the current of the energizing pulse is limited.

Abstract: The method is based on the exploitation of the "skin effect" occuring in any current-conducting material as a function of the current frequency going through said material. A transformer (5) is supplied from a generator (2) and an amplifier (4) to produce the current intended to supply the tube (T) and to measure the voltage at the terminals of a shunt (6). This voltage which is characteristical of the energization current is amplified by an amplifier (8) and brought to the reference input of a phase correlation amplifier (1). The resistive component of the signal on the tube is then measured by said amplifier (1) by just measuring the signal phase component.

Abstract: In a knitting machine, a selection latch having two end positions for selecting a knitting-needle is actuated so as to engage a cam which moves the selected latch towards a second end position. The actuation of the selection latch in two stages reduces the displacement brought about by the actuating means and increases the selection frequency. According to the invention the latch is actuated by a thin needle similar to a needle-printer needle, producing an impact on the latch, resulting in transmission of motion with high efficiency and moving the latch into an intermediate position in which the cam brings the latch into its second end position. This substantially eliminates friction between the actuating means and the latch, and enhances the selection frequency.

Abstract: In a knitting machine, a needle position control device comprises knitting needles each having five butts, of which one is fixed and the four others are secured in pairs to two needle latches mounted for oscillation in two recesses formed in the stem of the needle. A selection mechanism acts on the latches so as to move one or the other of their two respective butts out of the guide trick of the needle. By means of this combination of butts, the motion of the needle in the three knitting positions is constantly controlled in both directions of motion of the needle, by moving out two of the three butts. Another embodiment comprising a single latch can give the same result for two knitting positions.

Abstract: The printer comprises a series of needles (1) each associated to an electric lead (8) which extends in the gap of a permanent magnet (11). The extremities of each lead are fixed to respective supports (9,10) and are selectively connected to a current source to make a current (I) circulate in said leads so that, in the presence of a magnetic field in the air gap, a force (F) acts upon the lead (8) which communicates to the needle (I) an elongation (e) in the direction of the surface to be printed.

Abstract: The needles (1) of this printer are fed by an electrical conductor (10) associated with the secondary of a step-down transformer (9) connected to a current pulse generator (8). The needle (1) having been placed in the magnetic field of a permanent magnet (7), the current (I) which passes through the needle gives rise to forces which tend to restore this needle to a straight line joining its points of support and guidance (2,3) while displacing the free end against a writing support.

Abstract: This device comprises an electrode, the diameter of which is of the same order of magnitude as the drop to be projected, which emerges on the surface of an electrically insulating support. This support is immersed in a reservoir of liquid which comprises an opening. The support is placed so that the face thereof with which the electrode is flush, is located at a certain distance recessed from the plane of the opening so that it is covered with the liquid contained in the reservoir in which is located the counter-electrode. These electrodes are connected to a source of intermittent current designed to form an electric field through the liquid which, by concentrating on that part of the electrode emerging from the support, causes the projection of a drop of liquid.