摘要:
A method for continuously coating individual fibers of a fiber bundle with resin. The individual fibers are grouped at a single grouping pint defined by a first concave supporting surface. The fibers are directed through a resin bath while spreading the fibers apart on a convex surface in a regularly spaced arrangement to form a continuous coating of resin along at least a portion of the fibers. The convex surface is at least partially described by an arc rotated about a horizontal axis, and comprises at least a portion of a surface of maximum radius R which is symmetrical relative to a vertical plane of symmetry passing through the fiber grouping point. The convex surface is substantially defined by the equation ##EQU1## wherein: r=the radius of the arc at a distance x from the plane of symmetry passing through the grouping point;L=the length of a tangent to the symmetrical surface passing through the grouping point, in the plane of symmetry, between the grouping point and a point tangent to the symmetrical surface; and.phi.=the radian angle formed between the tangent and a vertical line passing through the center of the second surface.The coated fibers are cooled to harden the resin thereupon, and are collected thereafter.
摘要:
An apparatus for continuously coating individual fibers of a fiber bundle with resin, which comprises a first concave support surface for grouping the fibers of the bundle substantially at a single grouping point and a second, convex, support surface at least partially described by an arc rotated about its horizontal axis, having a maximum radius R, which at least approximately satisfies the relationship expressed in the following formula: wherein r designates the radius of the arc at distance x from the plane of symmetry, passing through fiber grouping point (P): ##EQU1## and wherein L designates the length of a tangent to the second support surface which passes through grouping point (P), in the plane of symmetry, and .phi. designates the radian angle formed between the tangent and the vertical line.
摘要:
The invention relates to phase-shifting cells constituting the passive reflectarrays of antennas with a reconfigurable transmission direction, transmitting in the microwave range. More particularly, the invention describes, within the context of phase-shifting cells of the type having dipole strands angularly distributed in a star configuration, a novel type of switch consisting of a microelectromechanical device essentially comprising a suspended micromembrane which, under the action of an electrostatic force caused by a control voltage, deforms sufficiently to ensure electrical connection between the strands, making it possible to form a dipole in the desired orientation. In one particular embodiment, the micromembrane can be likened to one of the plates of a capacitor and its deformation corresponds to a substantial increase in the capacitance of this capacitor, thus providing the electrical connection. This switch technology has the advantages of greater fabrication simplicity and of enhanced performance compared with the known technologies. The invention provides the main geometrical and technological characteristics for obtaining optimized performance.
摘要:
The invention relates to phase-shifting cells constituting the passive reflectarrays of antennas with a reconfigurable transmission direction, transmitting in the microwave range. More particularly, the invention describes, within the context of phase-shifting cells of the type having dipole strands angularly distributed in a star configuration, a novel type of switch consisting of a microelectromechanical device essentially comprising a suspended micromembrane which, under the action of an electrostatic force caused by a control voltage, deforms sufficiently to ensure electrical connection between the strands, making it possible to form a dipole in the desired orientation. In one particular embodiment, the micromembrane can be likened to one of the plates of a capacitor and its deformation corresponds to a substantial increase in the capacitance of this capacitor, thus providing the electrical connection. This switch technology has the advantages of greater fabrication simplicity and of enhanced performance compared with the known technologies. The invention provides the main geometrical and technological characteristics for obtaining optimized performance.
摘要:
A method for setting stones in the surface of a jewel produced by electroforming, comprising the following steps: producing a base having external shapes and dimensions with a thickness close to the gold film forming the wall of the jewel to be produced and having seats for receiving the stones; depositing on the base, before setting the stones, a protective coating, then a thin gold film; setting the stones in the seats; then depositing a second thicker gold film; and finally extracting or removing the base and the protective coating. The invention is characterized in that when the base is being produced, at least one passage is provided perpendicular to each seat, capable of communicating, once the stone is set, the space between it and the bottom of its seat with outside, so as to enable the depositing of the second gold film to reach the space. The invention is useful for jewels produced by electroforming.
摘要:
Device for regenerating digital signals transmitted along a coaxial line.So as to transmit information at flow rates greater than or equal to 650 Mbauds, the storage comparator of the invention is constructed in the form of an integrated circuit on AsGa and with negative threshold voltage MESFET transistors. It comprises an adjustable threshold voltage comparator stage, a type-D flip-flop for storage and resynchronization with respect to an external clock, and an output matching stage which may provide summation at its output.