Abstract: A device for the production of ink droplets as required includes a nozzle fed with liquid through a pipe connected to a tank and associated with a pressure transducer which produce pulsations in the liquid. The pressure transducer exhibits an internal cavity of very small volume with an inlet and an outlet for the liquid which is lying directly in contact with the wall of the material of the pressure transducer, this inlet being connected to the tank of liquid and to the outlet feeding the nozzle.

Abstract: A surface finishing device operates by means of a member designed for polishing, scouring, burnishing or the like and constituted by a resilient structure allowing some distortion along its longitudinal axis. This member has an annular constriction formed from its lateral surface, being designed as bellows formed of successive frustoconical sections.

Abstract: Process and apparatus for producing furfural from plant materials. The hydrolysis of pentosanes contained in plant materials is effected in a first reactor (2) in the presence of a strong concentrated acid, at 20.degree.-70.degree. C., at atmospheric pressure, and dehydration of the pentoses into furfural is effected in a second reactor (5) by vapor action at atmospheric pressure and at a temperature lower or equal to 110.degree. C., in a strong acid concentrated medium. Application: production of furfural.

Abstract: The reflector of an acoustic echo ranging system is matched so as to make up for the influence of the temperature at the bottom of the reflector, on the measurement of the back-reflected signal. The acoustic signal receiver being stationary the transmission frequency is controlled by a temperature responsive electronic circuit so that the receiver is always located at the same pressure antinode. Alternatively, the transmission frequency being fixed, the position of the receiver is controlled by a temperature responsive mechanical gear causing the position of the receiver to coincide with the same pressure antinode.

Abstract: A solar collector is designed for converting solar radiation into heat and transferring the heat thus collected, by means of a chamber formed of a window exposed to the sun and allowing passage of solar radiation, and of a bottom or opposite end-face. This radiation is absorbed by adequate means fitted inside this chamber, and the heat it entails is carried off outside the latter. Both the window and the bottom which form the chamber, are made of glass elements hermetically sealed to one another along their periphery by low-melt glass welding.

Abstract: A sealing device for a high pressure hydraulic piston mechanism in which the gap between the cylinder in which the piston is slideable to pressurize delivery fluid therein is sealed by sealing fluid drawn from a separate supply to that of the delivery fluid, delivery means being associated with the sealing fluid supply and being operable in response to pressurization of the delivery fluid to deliver sealing fluid to said gap at a pressure sufficient to form a seal therein, the sealing fluid of said seal being in direct contact with the pressurized delivery fluid and the piston being movable in at least one hydrostatic bearing supplied with sealing fluid in parallel to the supply thereof to said gap between the piston and the cylinder.

Abstract: A method of draining parts emerging from hot galvanizing baths using a range of vibration excitation frequencies capable of covering the fundamental frequencies of the parts to be drained. Three different methods are disclosed. According to a first method the vibrations are obtaining by exciting with a narrow band white noise the support for the parts to be drained. According to a second method, the vibrations are produced from a single exciter fed with narrow band white noise and energizing vibrators through the medium of amplifiers. According to a third method, the vibrations are produced by a number of small vibrators each of which furnishes one of the frequencies of the chosen spectrum, whereby said vibrators jointly synthesize the narrow band white noise.

Abstract: An equipment is described using n electrode sets implanted in the cochlea at n different locations for allowing the brain to identify n different frequencies. A receiver implant is coupled to the electrode sets through a selector and an external emitter is coupled to a single receiver coil of the implant by means of a single emitter coil. In the emitter the sound information signal is processed for forming n analysis signals of which the frequencies correspond to said n different frequencies and raster signals which are transmitted by modulating a high frequency a.c. signal. Each raster signal comprises at least n pulses of which the durations correspond to the energies to be transmitted to the n electrodes.

Abstract: The invention provides, at the end of a pipe which extends a valve being part of an exhausting device for pressure-relieving a pressurized fluid, a nozzle which is exactly at the input of a hood, the convergent portion of said nozzle reducing its exit section so as to make it substantially double the maximum passageway section through the valve.

Abstract: A solar energy collector having concave mirrors shaped as troughs of parabolic cross-section with a longitudinal pivotal axis enabling them to be aimed at the sun and having, at intervals, connecting members for maintaining at the mirror focus a heat receiving tube of small diameter by comparison with the mirror aperture. A dusttight and moisturetight transparent chamber isolates both the receiving tube and the surface of the mirror from the surrounding atmosphere.

Abstract: The gap between a bearing surface and the free edge of a wall extending opposite this surface and bounding therewith a volume of water or other liquid, is sealed against liquid leakages by a cushion of air or other gas surrounding the gap and having a pressure higher than that of the volume of liquid. This liquid is furthermore circulated along a closed circuit.

Abstract: Thin articles such as letters are conveyed over a supporting fluid layer formed against a track surface along which they move. This layer is built up by jets issuing from nozzles located on both sides of the track surface and opening flush with the latter. The nozzles are oriented towards the center line of the track with somme inclination in the direction of motion of the articles, in order that the velocity of the jets presents a longitudinal component parallel to this direction and a transverse component pointing towards the center of the track.

Abstract: A method of draining parts emerging from hot galvanizing baths using a range of vibration excitation frequencies capable of covering the fundamental frequencies of the parts to be drained. Three different methods are disclosed. According to a first method the vibrations are obtaining by exciting with a narrow band white noise the support for the parts to be drained. According to a second method, the vibrations are produced from a single exciter fed with narrow band white noise and energizing vibrators through the medium of amplifiers. According to a third method, the vibrations are produced by a number of small vibrators each of which furnishes one of the frequencies of the chosen spectrum, whereby said vibrators jointly synthesize the narrow band white noise.

Abstract: Apparatus for heating elements broken up in small pieces wherein the pieces are loaded into baskets with solid vertical walls and perforated or porous bases, and are pushed in a continuous line into a tunnel to there introduce a hot gas which passes vertically through each basket and its contents. A principal application is the preheating of products feeding a smelting or resmelting furnace, and in this case the hot gases used are fumes from the furnace.

Abstract: The invention comprehends a sound proofed valve for fluid under pressure, comprising a movable obturator for progressively uncovering a series of fluid expansion orifices positioned inside an expansion area, a sound proofing means also positioned inside said expansion area and located opposite fluid jets issuing, in operation of said valve, from said orifices, and a permeable splash guard obstacle placed between said orifices and said sound proofing means and spaced from said sound proofing means.

Abstract: The swell of a body of water is abated by dissipation of its hydraulic energy in response to variations of water head under the crest and under the trough of the waves. For this purpose, an enclosure is toto submerged in this body of water. It has on the one hand orifices designed to allow only a one-way flow of water upon exertion of a differential pressure of given sign, and on the other hand restricted or throttled passages designed to produce duct losses upon traverse thereof by water.

Abstract: A liquid level gauge or like meter designed to provide a reading of prolonged duration, is operated by means of a push-button which, upon depression by exertion of a push on its head, activates the basic sensor element of the meter which controls its index. The latter is located inside the push-button, under the head thereof which protects it against shocks and soil; it can be viewed through this head which is of transparent material. The index has a section which is carried by the transparent head of the push-button and is movable therewith. The required prolonged duration readability of the index is available after release of the push-button head.

Abstract: A heat-exchanger for fluids is designed with an outer cylindrical casing and, inside the same, a plurality of coaxial heat-exchange surfaces forming axial flow passageways for fluids therebetween, with two ends each bearing a connection-box for the fluid inlets and outlets. This connection-box is connected to the outer peripheral heat-exchange surface and includes partitions extending from the axis to the periphery and engaging the edges of the heat-exchange surfaces. Obturators join pairs of edges of successive heat-exchange surfaces whereby each end of the succession of heat-exchange surfaces offers annular passageway portions and annular obturated portions.

Abstract: Pasty materials are mechanically dried by passing them through a pressing zone established between conjugate elements for subjecting the material to be treated to the action of pressure in direct contact with the free surface of a layer of open and communicating cell foam which serves as a sponge and is supported by its surface opposite to said free surface against a wall for the application of pressure in such a manner that the spongy layer becomes impregnated in the said pressing zone with liquid previously contained in the said material to be treated. The liquid is caused to pass right through the spongy layer up to its opposite surface while filtering through the open communicating cells. It then issues from the supporting wall -- which is porous to this end -- so as to be finally evacuated.

Abstract: A conveyor apparatus is designed for the propulsion of metal sheets and more specifically sheets of ferromagnetic material. It operates by means of a linear induction motor associated with fluid cushion developing shoes. The apparatus is arranged to be movable perpendicularly to the sheets, its weight being counter-balanced so as not to react thereon. It is useful for sheet distributing machines.