Abstract: The invention relates to components such as pyroelectric sensors which are particularly sensitive to piezoelectric effects and which, consequently, are disturbed by the mechanical deformations or the vibrations which the component may experience. In order to limit these disturbances, it is proposed to insert, between the chip (10) carrying the pyroelectric layer and the bottom of the package (30), a flexible sheet (42) of silicone which absorbs the deformations of the package without transmitting them to the chip. Ultrasonic bonding of the connecting wires (34) is still possible despite the presence of the flexible sheet. The chip is preferably fixed to a metallized ceramic plate (40) and abutments (44) are preferably provided at the bottom of the package in order to limit the compression of the flexible sheet (42) during the bonding operation.

Abstract: A compact image sensor is disclosed. This sensor comprises an insulating, imperviously sealed package, provided with a window which is transparent to light rays and is located on a front face. The inside of the package contains a stack arrangement which comprises, between the back of the package and the window, an insulating support, a set of photosensitive elements with a semiconducting substrate, surrounded by contacts. Connection terminals go through the back of the package and the insulating support. Connection means are interposed between these contacts and the ends of the terminals. The light rays are received by the photosensitive elements after they have crossed the semiconducting substrate which is thinned down beforehand. This arrangement of the photosensitive elements, the substrate and the connection means enables an appreciable increase in the area of the photosensitive surface and in the number of connection terminals, without an increase in the area of the front surface of the sensor.

Abstract: The invention uses a strip of infra-red detectors comprising a cold screen of the type that provides a constant viewing angle for all the directors in a direction that is prependicular to the axis of the strip. Two cylindrical mirrors are set at the ends of the strip and placed in the heated part of the cryostat containing the strip and the cold screen. The shape and dimensions of the mirrors as well as their positions are chosen so that the detector placed in the center of the strip detects, through reflection in two mirrors, only cold surfaces while the other detectors detect heated surfaces, through reflection in the two mirrors, in a proportion that increases with distance from the central detector of the strip, so that, along the axis of the strip, every detector has a substantially constant viewing angle. Applications: large-sized strips, for example in space applications.

Abstract: The mixture is produced in the liquid state by first of all introducing in a reservoir (2) the most volatile substance in the liquid state and then circulating in a coiled tube (6) immersed in this liquid the other or each of the other substances in the liquid state before causing it to fall in the form of a spray in the reservoir. Application in the obtainment of reconstituted air.

Abstract: The liquid is drawn from this vessel through a coiled tube (20) provided with a calibrated valve (21) at its inlet. The resulting drop in pressure is compensated for by means of a pressure raising circuit (27). Application in the storage of liquefied air.

Abstract: The device comprises a reservoir having a double wall 4-5 with an inlet pipe 24 having a valve 31 whose movable valve member 30 is connected to a float 35 and a drawing-off pipe 41 having a valve 45 whose valve member 50 is connected to a control rod 52. The drawing-off valve 45 is placed in the thermal insulation space of the reservoir. Application in the distribution of low and usually intermittent flows of cryogenic liquids and in particular nitrogen or argon for rendering inert pouring jets employed in metallurgy.

Abstract: A small size e.g. 12 mm diameter by 40 mm long cryostatic device with photodetectors. A hollow finger having the photodetectors at one end is adapted to be brought to a very low temperature by a cold fluid circulating in the finger. A wall or housing surrounds finger and provides a vaccuum space surrounding the finger. A window made from a material transparent to the radiation to be detected forms part of the wall and faces the detector. The cold finger is made from a ceramic material which is either a tight ceramic or a sealed ceramic which has low thermal conductivity.

Abstract: The present invention relates to a method of and a cryogenic installation for distributing gases.From a storage tank at low pressure, successive portions of cryogenic liquid are withdrawn to an enclosure, which is isolated by closing a valve. After this, a further valve is opened, the effect of which is to cause the pressure in a receptacle to rise to the high distribution pressure and to allow the gas concerned to condense to a certain degree so that said enclosure is filled with liquid under pressure. The liquid evaporates partially at the periphery and is thus transferred to a heater and from there to a buffer container.The invention is applicable in particular to the distribution of oxygen, nitrogen and argon under pressure.

Abstract: A miniature open circuit refrigerator of the Joule-Thompson type, functions as a demand cryostat by virtue of a pressure-operated refrigerant supply control. The refrigerant fluid under high pressure is introduced at a first relatively rapid flow rate into the cryostat through a calibrated opening that is fully open during the initial or start-up period of the device, for rapid cool down. This calibrated opening is thereafter at least partially closed by a valve which is urged open by a spring and which is urged closed, against the action of the spring, by a bellows containing a gas at high pressure and which is exposed on its outer side to at least a portion of the pressure of the refrigerant fluid. Upon the fall in pressure of the stored refrigerant fluid, toward the end of the start-up, the bellows expands so as at least partially to close the valve, thereby to decrease the flow of refrigerant during the final portion of the cool-down period and during the steady state or on-stream operation of the device.

Abstract: This invention relates to containers for liquified gases, of the kind which comprise an inner container intended to hold the liquified gas which consists of a container body and an elongated neck, and an outer shell spaced away from the said inner container which forms with the latter an evacuated insulating space packed with material made up of successive superimposed layers of materials which are alternately conductive and insulating, marginal portions of the said layers of conductive material being in individual thermal contact, along annular areas spaced above one another, with the neck of the inner container, which extends to the said outer shell. According to the invention, the neck of the inner container is made from a plastics material, the thermal contact between the screening layers of conductive material and the neck being ensured by simple free contact under pressure. The inner container may be made from resin or glass, either of which may be reinforced by fibres.

Abstract: A method and apparatus for generating low temperatures, of the type which employs two regenerators whose hot ends are connected via changeover valves alternately to the input and output of a compressor and cooler assembly and whose cold ends are connected by a constricted passage which form a cold source. In accordance with the invention, the changeover valves are controlled by means which are subject to a reference pressure.