Abstract: The invention relates to a mechanical valve prosthesis that includes a base having an external portion forming a suture ring, and an internal portion forming a rim, in which a blood flow can move in a main flow direction (F), as well as at least two closing leaflets (10) which can move, under the action of the blood flow, between a closed position and an open position, and vice versa. The opening occurs in the physiological direction, that is from the axis of the rim (3) of the center of the prosthesis and thus toward the rim. A region (40) of each one of the leaflets (10) borders, in the open position, a natural wall and defines with it the peripheral duct regions (19). The region (40) of each leaflet (10) presents a zone (22) in which, in the closed position, it turns its concavity toward the rim (3). In this manner, when the leaflet (10) is in the open position, the peripheral duct regions (19) present a form which produces a beginning of closing of the valve (10) during the deceleration of the blood flow.

Abstract: An end station of a both-way optical link comprises: a receiver (RX) preceded by a receive optical amplifier (RA); a transmitter (TX) followed by a transmit optical amplifier (TA); a pump laser diode (PX) for delivering the pumping waves required by said amplifiers; and a coupler (B) of the passive type having two groups of two branches. The two branches of one group (BL and BP) are connected respectively to a line fiber (L) for both-way light guidance and to the pump (PX), the two branches of the other group (BR and BT) being connected respectively to the receive optical amplifier (RA) and to the transmit optical amplifier (TA). An in-line optical amplifier apparatus can be constituted in similar manner. The invention is applicable to telecommunications.

Abstract: The invention relates to a temporary towing device intended to impart a very high acceleration to a mobile mass (A, TAV, CF). It comprises a guidance device (G), a carriage (C) mounted so that it can slide with respect to this guidance device (G), a motive device (M, PI) for imparting a movement of acceleration along this guidance device (8, 9) to the carriage (C) in a direction running in the direction of acceleration of the mass (A, TAV, CF). Coupling means (CR) make it possible temporarily to secure the mass and the carriage together as they are accelerated. A braking device (F) makes it possible to brake the carriage at the end of the acceleration of the mass.A device (1) for modulating the towing force (EC) is designed to bring the elements (TAV, CF) of the mass (A, TAV, CF) to the state of rest with respect to one another, or close to this state of rest, the moment the connection is broken.Application to the catapult of an aircraft carrier.

Abstract: A simple implementation of a high-capacity switching matrix includes four input functional modules each having one input and four outputs and four output functional modules each having four inputs and one output. A broadcast network has 16 inputs connected to the 16 outputs of the input functional modules and 16 outputs connected to the 16 inputs of the output functional modules to broadcast four signals from each input functional module simultaneously to each output functional module. The broadcast network includes four send subsystems each sending four optical carriers at four different wavelengths .lambda..sub.1, . . . .lambda..sub.4 and four receive subsystems each receiving four optical carriers at these respective wavelengths. The broadcast network further includes four optical buses each connected to a respective input of a receive subsystem and to a respective send subsystem so that the jth bus for j=1 through 4 receives from the kth send subsystem the carriers at the wavelengths .lambda..sub.

Abstract: A wind-propelled hydrofoil comprising a forward assembly with at least partially submerged forward foils and a fully submerged aft foil. The forward foils (43, 44) are such that the resultant of the vertical forces drops when said assembly is translated vertically upwards, with a heave characteristic (F), and increases when said forward assembly is subject to upward pitching, with an incidence characteristic (A). The aft foil (46) has an incidence characteristic (R) such that R(d-g)-Ag+F(g.sup.2 +r.sup.2)>0, wherein d is the distance between the aft foil (46) and the center of heave, g is the distance between the center of gravity and the center of heave, and r is the gyration radius of the hydrofoil.

Abstract: An add-drop optical spectrum-division multiplexer for dropping a drop multiplex from an incoming multiplex signal and for adding an add multiplex into an outgoing multiplex signal. The multiplexer includes a demultiplexing device for separating a number of optical carriers from the incoming multiplex signal and for selecting drop carriers which constitute the drop multiplex as well as through carriers which are to be output as the outgoing multiplex signal. The multiplexer further includes an apparatus for selecting a certain number of add carriers from the total number of carriers of the add multiplex, and a coupling device and wavelength converter for allocating fixed wavelengths to the signals which modulate the through carriers and the add carriers.

Abstract: Bidirectional transmission over a single optical fiber is obtained in an optical communications system by using a three port circulator in customer premises equipment together with an optical fiber amplifier and a narrow band filter. The fiber amplifier can be locally or remotely pumped. The acousto-optic modulator is advantageously used because it reduces the coherent Rayleigh noise by detuning upstream and downstream wavelengths.

Abstract: An optical connection system for connecting customer premises networks to a switching center of a telecommunication network providing interactive and non-interactive services includes a switching center comprising central office termination equipments, a connection network, a control unit, an optical distribution network and customer premises networks. Non-interactive services are connected to the control central office termination equipment so that non-interactive service signals are sent to all customer premises networks on standby at the control central office termination equipment wavelength. These customer premises networks can therefore use these services without having to set up a call individually and so without having to busy a central office termination equipment for each customer premises network.

Abstract: A molded case circuit breaker includes standard compartments each designed to accommodate a standard auxiliary indication or control unit. Each compartment is assigned to a predetermined function, the control device associated with this compartment being connected to the corresponding components of the circuit breaker supplying the information relating to this function. Customization of the circuit breaker can be performed by the distributor or fitter who fits a standard auxiliary unit in the compartment or compartments.

Abstract: An automatically configurable optical connection system for connecting customer premises networks to a switching center of a telecommunication network includes an optical distribution network connecting all central office termination equipment optical senders to all customer premises network optical receivers and connecting all customer premises network optical senders to all central office termination equipment optical receivers. A control unit assigns a different wavelength to each customer premises network communicating at a given time, this wavelength representing an available central office termination equipment which is not the control central office termination equipment.

Abstract: This bidirectional transmission system, especially one using optical fiber, between a source terminal and a user terminal employing a single carrier for both transmission directions obtained from a source in the source terminal characterized in that it comprises for each transmission direction means for modulating one parameter of said carrier, this parameter being intensity for the two directions and subject in all cases to the condition that the modulation applied first for transmission in the downward direction from the source terminal to the user terminal the depth of modulation is sufficiently high to leave sufficient power for application of the second modulation to which that applied second can be applied for transmission in the upward direction from the user terminal to the source terminal.

Abstract: An operating for a circuit breaker including a pivoting handle for controlling opening and closing of the circuit breaker and resetting of the latch after tripping. The handle bears a resetting roller which cooperates with a cam surface of the latch, which surface has a first cam section and a second cam section separated by a slope change point. The second section corresponds to the reset position and the slope of this section is chosen in such a way as to obtain a stable reset position of the handle.

Abstract: A modular low voltage multipole circuit breaker, including a plurality of identical single-pole breaking units each including a parallelipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact cooperable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch.

Abstract: A low voltage multipole circuit breaker having a double housing, each pole including a single-pole breaking unit having a parallelepipedic plastic box having two extended side faces. Contacts are further provided and are associated with an extinguishing chamber housed within the single-pole breaking unit. Several units are mounted side by side in the parallelepipedic box to form a multipole circuit breaker.

Abstract: A prosthetic heart valve comprising a base and at least two flaps. The valve includes means for guiding the flaps and for retaining them, said means being constituted, for each flap, by: two arcs for guiding the trailing edge of the flap; and at least one arc for guiding the leading edge of the flap. The invention is applicable to the manufacture of prosthetic heart valves.

Abstract: This invention describes a tunable optical filter to be used in an optical communication system. The filter of this invention has a pair of resonator cavities which are cascaded. The lengths of each of the cavities change simultaneously with the change in length of a piezoelectric sleeve which contacts a reflective surface of each of the cavities through spacers. The sleeves and spacers are set so as to move the reflecting surfaces of the cavities along a single axis in response to a single control signal. When optical signals are passed through the two cavities and when the ratio of the length of the cavities is adjusted to a predetermined ratio of integers, the resonator cavity will resonate at a desired wavelength.

Abstract: An optical message distribution system is described which includes both a plurality of message sources and destinations. Each optical message includes a destination address portion and a data portion containing data signals. At a message source, an encoder generates, for each data signal of one kind, an optical pulse whose time position relative to a frame is indicative of a message destination address. An optical summer, common to all message sources combines the optical pulses onto an optical transmission medium and transmits them to an optical decoder associated with the each message destination. Each optical decoder determines if the time position of a received optical pulse relative to the frame is equal to a preset time delay, and if so, generates a data pulse of the one kind for the message destination.

Abstract: An optical communication system is described wherein a message pathway is indicated by a destination address, manifested by an address time interval between a reference optical signal and an address optical signal. The optical communication system includes an optical switch for directing messages onto selected pathways. The switch includes a gate summer, and a reference circuit for applying a destination address portion of a message to the gate summer. A first delay circuit also applies the address portion of the message to the gating summer, while retarding it by a first address time interval. The gate summer sums the address portion from the reference circuit and the retarded address portion to produce a gating signal when the reference optical signal and address optical signal are time coincident. Switch means are further provided which are responsive to the gating signal to direct the message along a first selected pathway.

Abstract: The limiting circuit breaker comprises a Thomson effect propelling device for opening of the contacts.The main contact bridge is securedly united to an operating rod surrounded by an annular opening coil of the propelling device. The latter comprises an opening disk which is movable in relation to the rod and an annular piston securedly united to the rod, springs being disposed between the disk and the piston, so as to return the disk to the rest position facing the coil at the end of the opening travel.

Abstract: A tunable optical filter having a number cascaded resonator cavities with each cavity having electro-optic material in its interior. The resonator cavities will resonate at a select wavelength when the index of refraction of the electro-optic material is changed to a predetermined value in response to only a single control voltage. The index of refraction of the electro-optic material is adjusted to a predetermined value by application of the single control voltage to one of a pair of electrodes which are on opposite sides of the resonator cavities.