Abstract: The switching aid device includes, in the case of a main static switch, (1), a switching aid capacitor (10), parallel connected to the main static switch (1) via a loading diode (11) and, parallel connected to the latter, a series set up formed by an anti-return diode (12), primary winding (13) of transformer (14) of which secondary winding (15) is connected to an energy recovery circuit on an electrical power source (4) via diode (16) and an auxiliary static switch (17) fitted with control means (20) for closing the auxiliary switch in presence of an inverse voltage at the terminals of loading diode (11) and for opening the auxiliary switch in absence of such voltage.

Abstract: The rollers (2) carrying a steel strip (1) to be heated between two rolling mill procedures are mainly constituted by a lamination of magnetic sheet metal plates to channel the variable magnetic flux generated by inductors which consist of magnetic circuits (4) and field coils (5), and so that the rollers are not heated up by this flux.

Abstract: As known the product to be heated (7) is made to scroll longitudinally in the flow of an inductor (IC) with a dual frequency along a longitudinal pitch and along a transverse pitch. According to the invention this produce is made to scroll in the flow of two successive inductors with a common transverse pitch (PT) which is adjustable (31a) practically between the two longitudinal pitches of these two inductors, this transverse pitch is set to make the width of this product coincide with an integer number of transverse pitches thus obtaining the same heating on the two edge areas (7a, 7b) of this product as on the intermediate areas, and firstly the ratio of the currents supplying these two conductors is set to homogenize the heating in each transverse pitch, and secondly the total power adjusted to reach the temperature required. The invention applies to metallurgy.

Abstract: Electromagnetic pump for electrically-conductor fluid containing an external pipe (1) enveloped by magnetic half-yokes (11, 11') containing slots (14) in which half-coils (19, 19') are installed forming two polyphase half-windings (35, 35') permitting a symmetry plane.The fluid is contained in a duct (31) comprised between the external pipe (1) and an internal pipe (5) which is closed and contains a magnetic core (24). The duct (31) is provided with partitions (29, 29', 34) which separate the duct (31) into two active half-ducts (32, 32') in which the fluid flows and two passive streams (33) in the vicinity of the joint plane in which the fluid scarcely flows at all.Pump with a high degree of efficiency and easy to dismantle.

Abstract: A thyristor (TR) is used to switch over between traction and braking states. Rather than supply a special extinction circuit for the switch-over thyristor, it is connected to make use of the extinction circuit already provided in the chopper circuit (H).

Abstract: A method and system for controlling the heating of a product in an electromagnetic induction heating installation having a pair of essentially identical inductors placed on either side of the product with the poles of one of the inductors of the pair facing the poles of the other inductor. The average heating power electromagnetically induced in a moving or stationary, flat, conducting product positioned without contact by electromagnetic forces correlatively induced by the electromagnetic heating field is controlled by effecting a sequence of inversions of the instantaneous polarity of the poles of one of the inductors with respect to the instantaneous polarity of the corresponding poles of the other inductor. The ratio of the durations during which the polarities are on the one hand opposite and on the other identical determines the average value desired of the heating power induced, and the position of the product remaining practically unchanged by said inversions.

Abstract: A method and apparatus for minimizing the power induced in a moving or stationary, flat, conducting product which is maintained in position without contact by electromagnetic forces. Inductors on each side of the product subject certain zones of the product to two alternating, essentially equivalent, opposing magnetic fluxes acting perpendicularly to surfaces of the product on opposite sides thereof so that, in each of the zones, with the product in a position of equilibrium, the component of magnetic flux of the resultant field perpendicular to each zone is minimal and the component parallel to each zone is at a maximum, due to the mutual deflection of the two fluxes. Each inductor has a plurality of poles and the opposing fluxes are produced by generating magnetic fields of like polarity in opposing poles of the inductors while generating, in adjacent poles of the inductors themselves, magnetic fields of opposite polarities.

Abstract: A continuous current electric machine with a cylindrical air gap and with permanent magnet stator excitation in which stacked sheets forming the stator of the continuous current machine have closed cut-outs of a polygonal contour extending therethrough such that each closed cut-out extends into the immediate proximity of at least one of two ends of an effective region of a pole forming the air gap and leaves only a very narrow strip of the sheet between the cut-out and the air gap. At least one magnetic plate, preferably of a rare earth, is inserted in each cut-out to thereby form a permanent magnet pole. Each cut-out comprises a series of rectangular slots in the shape of a V or a U, the opening of which is oriented toward the corresponding effective region of a pole. One embodiment includes at least one wound pole formed on the stacked sheets so as to equip the electric machine with a hybrid, permanent magnet and wound inductor.

Abstract: A process and apparatus for inductive heating of flat, thin, conductive, nonmagnetic products of variable dimensions. A plurality of currents are inductively generated in the product in such a way that elementary current arrays are formed in the product in both the longitudinal and lateral directions. Current arrays of local heating heterogeneity, each comprising at least one of the elementary current arrays, are defined, and the intensities of the inductively generated current in the arrays of local heating heterogeneity are controlled as a function of the volume of the array of local heating heterogeneity with which they are associated, so that the average value of power dissipated per unit volume in each array of local heating heterogeneity is approximately the same as for all other arrays. The apparatus specifically includes an inductor with individually controllable coils (poles) arranged to extend longitudinally and laterally over the area of the product to be heated.

Abstract: Magnetic induction heating apparatus for flat, rectangular metal products travelling in the direction of their longitudinal axis, comprising at least one inductor mounted so as to rotate about an axis perpendicular to a wide face of the metal product and comprising at least two magnetic poles having polar surfaces sweeping out an annular area as the inductor rotates about the perpendicular axis. In order to effectuate the homogeneous heating of the metal product in the transverse direction, the polar surface of each magnetic pole has the shape of a curvilinear triangle with a truncated apex directed toward the axis of rotation of the inductor, two concave sides which are symmetric with respect to a straight line passing through the truncated apex and perpendicular to the axis of rotation, and a convex side of circular arc centered about the axis of rotation having a radius of curvature essentially equal to the external radius of the annular area sweep by the polar surfaces of the magnetic poles.

Abstract: A cooling water distribution system for an air cooler includes a condenser that is subdivided into two independent bodies forming separate compartments, one or the other of which may be temporarily shut down. The water distribution system itself may be, similarly to the condenser, subdivided into two independent hydraulic circuits, each having its own pump and serving its own sprinklers, so that in the case of the shutdown of one of the two hydraulic circuits, the sprinklers in the other circuit remain in service, as they continue to be normally supplied without being affected with repect to their supply by the shutdown of the first circuit. The invention is particularly applicable to central air conditioning installations.

Abstract: Continuously moving, elongated, thin work products are subjected to homogeneous electromagnetic inductive heating in the transverse direction. The heating is achieved by an induction heating apparatus having a rotating inductor with a plurality of magnetic poles and an adjustable yoke. The inductor is rotatable about an axis and the work product is guided by a rotatable support in a loop path coaxial with the axis. The yoke includes at least two elements that are movable relative to one another to vary gap between the inductor and the yoke to thereby generate a traverse profile of the resultant moving magnetic field across the width of the work product. The magnetic field is uniform in the center zone of the work product, then at either edge of the work product, first increases and then subsequently decreases to a value below the uniform field with increasing distance away from the center zone.

Abstract: A translating field inductor for the stirring roller of a continuous slab caster includes a grooved arbor carrying flat magnetic sheets disposed parallel to the axis of the arbor, the latter and the sheets being notched by a series of circumferential grooves spaced over the length of the arbor and housing circular induction coils. In order to concentrate the magnetic flux on the moving slab in the course of the continuous casting, the arbor is stationary and is made of a nonmagnetic metal with good electrical conductivity. It has a longitudinal groove with a wide transverse cross section housing a single packet of sheets, which constitutes the magnetic core of the inductor. The arbor forms a screen for the magnetic flux generated by the induction coils with the entire assembly being such that the magnetic flux is oriented in a fixed, prescribed direction.

Abstract: This invention pertains to a direct current, series excited traction motor, the armature coil of which is connected in series with the field coil and a smoothing coil, and the power supply of which is adjusted by a current chopper. The inductor includes, in addition, a shunting device for reduction of excitation, and a free wheeling diode is in parallel with the motor and the smoothing coil. This device is unique in that the field coil is divided into at least two series connected partial coils to generate additive flux, one of them only being provided with the shunting device. The chopper is advantageously of a type which may operate in a continuous conduction mode.

Abstract: A brush-holder for rotating electrical machines includes a brush and a compression spring disposed in a shaped metallic sleeve encased in an insulating support adapted to be mounted on the frame of the engine. The insulating support includes at least one projecting stop which cooperates with a notch provided on the sleeve, so that the sleeve is precisely located at a predetermined longitudinal position within a sheath on the support. In addition to positioning the sleeve, the stop also serves to limit travel of the spring as the brush wears down.

Abstract: A process is provided for the separation of a gas and a condensable vapor present in the gas. The vapor-containing gas is contacted in a condensation zone with a heat-exchange fluid to cool the gas whereupon the vapor condenses and is collected as condensate. The condensate is then contacted with the heat-exchanger fluid to cause it to vaporize.

Abstract: An electromagnetic inductor for generating a helically moving magnetic field includes a first magnetic circuit having an annular core with radially inwardly projecting teeth and a winding for generating a rotating magnetic field, and a second magnetic circuit formed by foliated bars and a second winding comprising an axial series of circular coils for generating an axially moving field. The two fields combine to generate a field with helical movement. At least some consecutive teeth of the core are hollowed to provide axial grooves in which the foliated bars are disposed. The coils of the second winding are cylindrical and set inside the cylindrical volume defined by the teeth. The inductor is particularly adapted for the electromagnetic rabbling of a billet in a continuous casting process.

Abstract: An electromagnetic centrifuging inductor structure for creating a rotating magnetic field for rotating molten metal about its casting axis while passing through the casting conduit of a continuous casting type ingot mold includes an annular core body of magnetic material surrounding the casting conduit and which is provided with six poles or teeth on which are respectively mounted six different arcuate coils for energization by a three-phase a.c. source. Two coils are provided for each phase and these are so distributed that two coils of the same phase have different radii, are mounted on two diametrically opposite teeth and are coupled in such manner that their generated magnetic fluxes are additive. The coils are mounted in recesses formed between adjacent teeth and the coils of different phases partially overlap within the same recess.

Abstract: An air-tight molded resin enclosure for containing a fluid under pressure is disclosed. The enclosure includes a safety membrane which can rupture at a fluid pressure less than the pressure at which the enclosure will rupture. The enclosure may contain an electric device such as a circuit breaker and a pressurized insulating fluid such as sulfur-hexafluoride (SF.sub.6) gas. When an electric arc occurs in the circuit breaker, the pressure of the gas contained in the enclosure increases in magnitude. When a sizable over-pressure exists inside the air-tight enclosure, the safety membrane will rupture without damage to the circuit breaker or to any neighboring equipment. The safety membrane includes grooves which act as rupturing primers. The thickness of the safety membrane and the depth of the grooves determine the pressure at which the safety membrane will rupture.

Abstract: An airconditioning system includes a heat exchanger having high and low temperature heat exchange chambers in which a fluid is cooled or heated, respectively. An air circuit is associated with each chamber. A register having four orifices and a valve is associated with each air circuit, and the system can easily be switched from a heating to a cooling mode, or vice versa, by actuation of the valves to cause the air entering the environment to be conditioned to flow through a selected one of the two air circuits.