Abstract: An arrangement for storing cryogenic liquid comprises a Dewar-flask-like vessel. The vessel is filled completely with a material able to absorb a cryogenic substance when said substance is in liquid form but only capable of absorbing said substance to a limited extent when said substance is in gas form. Adjacent to the mouth of said vessel and externally thereof there is provided a cavity, which is arranged to cooperate with means by which any gases formed in said cavity can be released to atmosphere when the pressure in said cavity exceeds a given pressure.

Abstract: In an apparatus for mixing in given proportions two media, such as gases or liquids, the pressure of each said media is reduced to a working pressure by a respective regulator. The media from the regulators pass through a mixing means to a common mixing chamber through two gaps each of which is individual to a respective medium. The relationship between the length of the two gaps can be adjusted by means operative to control the proportions of the media in said mixture and the regulators are arranged to be controlled in a manner such that the pressures of the media before the gaps are held mutually equal.

Abstract: An arrangement is provided in a respirator for measuring the amount of gas passed to a patient through a supply line. The arrangement includes a self-oscillating fluidistor for dividing the gas flow into part volumes of a given magnitude and for generating an electrical pulse for each part volume passing therethrough. The fluidistor includes two outputs and a control channel having a temperature-dependent resistor located therein and an amplifier and pulse-forming circuit connected to the resistor so as to generate electrical pulses whose number is related to the number of part volumes flowing through the control channel of the fluidistor. A binary counter is connected to the amplifier and pulse-forming circuit for counting the number of pulses over a predetermined time interval while a digital-to-analog (D/A) converter, having first and second inputs, generates an analog signal corresponding to the number of pulses produced per time interval.

Abstract: A device for keeping an outer surface of an optical element clean, said element being located in surroundings where deposits can be quickly formed on said element. The device has a protective device or screen with an opening placed in front of the surface to be protected. This opening has inner walls extending out from said surface of the optical element. The screen has a slot, which extends peripherally around the edge of the opening facing the surface to be protected, and gas is forced to stream through the slot. At least a part of the inner surface of the opening has an inwardly projecting part having a surface remote from the optical element which is parallel to or inclined outwardly from a symmetrical plane through the element.

Abstract: In the decomposition of ozone in aircraft, the ozone level in an airflow upstream of the aircraft cabin is measured and a signal generated in accordance with the sensed level. This signal is amplified to a given value and a valve is opened or closed in response thereto. Connected to the valve is a source of nitric oxide under pressure. When the valve is opened a measured quantity of nitric oxide is dispensed to a location in said airflow remote from said ozone monitoring device.

Abstract: A method and apparatus are provided for balancing out interference caused by stray coupling between the internal circuits of a distance measuring apparatus of the phase-type in a simple manner which produces a substantial increase of the usable measuring range. At least two groups of mutually separate distance measurements are performed, with each group including at least one measurement operation. For each pair of groups of distance measurements, one measuring group is effected with the transmitter signal in a first phase and the other measuring group is effected with the transmitter unit of the transmitter section supplied with a transmitter signal in a second phase which is displaced substantially 180.degree. relative to the first phase. The mean value or the mean values of the measuring results in each measurement group are thereafter formed, with this calculation being made either by hand or automatically.

Abstract: Apparatus is disclosed for measuring the distance to a point on the inner wall of a hot furnace.

Abstract: A compact, highly versatile, modular solar energy collector is achievable through the employment of well distributed bypass flow components providing a bypass mass flow within a given range across a thin collector face, in conjunction with a low height, laminar interior flow having a predetermined proportionality to the bypass flow. A short flow path length along the collector together with the bypass flow relationship and other parameters permit high temperature differentials to be attained, accompanied by high efficiency. Further, the mass flow through the collector may be varied within a substantial range in response to changing insolation conditions while maintaining the bypass flow in an acceptable range by incorporation of a pressure drop having mass flow dependent characteristics in the principal flow path.

Abstract: An electromechanical positioner indicator is provided which comprises first and second relatively movable parts, the first part including two oppositely facing surfaces which are everywhere equidistant and the second part including two surfaces which are everywhere equidistant and which are everywhere equispaced from and lie, closely adjacent to respective ones of the two surfaces of the first part. A first coil, preferably in printed circuit form, is secured to the first part and sensing coils, also preferably in printed circuit form, are secured to each of the two surfaces of the second part. The inductive coupling between the coils is dependent on the relative positions of the parts and thus the output of the sensing coils provides an indication of position. In one embodiment, the surfaces in question are formed by cylinders and in another, the first part is a disc and the main coil comprises an annulus. Particular coil and coil conductor shapes are also disclosed.

Abstract: A readily fabricated, high efficient modular solar energy collector that may be arranged in a wide variety of arrays comprises a relatively small, typically but not necessarily rectangular, panel structure that is centrally coupled to an insulative support that may define an outlet conduit. In a specific example, a pair of coextensive, thermally conductive panels, the outer one of which preferably has a light absorptive black upper surface of low emissivity, defines flow paths directed laterally inwardly from side margins of the panel to a central mid-line region at which outlet apertures flow into a manifold region under the panel. The heated fluid in the manifold communicates with an outlet conduit within the support that is connectable at its respective ends to like conduits of adjacent modules. The centrally supported panels are sufficiently rigid to need no additional support, and freely expand and contract in response to temperature changes.

Abstract: A method and apparatus are provided for producing a color thermogram on a color film beginning with images, such as those of a black and white television monitor, projected on the color film through color filters, with preferably three achromatic images being formed. The intensity of the achromatic color in each image as a function of temperature is selected in accordance with a predetermined characteristic or relationship and the images are projected through a color filter having a separate color for each image, e.g., blue, yellow and red. In this way the same portions of the image with achromatic colors which conform to the characteristic selected for the different filters are projected through the different filters, so as to produce a picture having color hues which vary between the colors of the filters. For example, a green hue is produced for an "overlap" of the characteristics for blue and yellow.

Abstract: A method and apparatus for cleaning a surface of an optical element, such as germanium or silicon, of a larger arrangement, such as an infra-red camera. Cleaning liquid is applied to the surface and vibrated at a frequency to facilitate cleaning, such as 20-50 kHz. The invention is readily utilized in situations where the optical element frequently becomes dirtied such as in military equipment. A liquid container for the cleaning liquid has an outlet adjacent the surface to be cleaned. A vibrating device is also provided and may be directly on the surface or on a member adjacent thereto. The liquid is applied to the surface and the vibrator is actuated to vibrate the liquid to facilitate cleaning.

Abstract: A method of making a series of measurements of the relative position of a point on the surface of an object in an object related coordinate system is disclosed. The object is turnable around an axle. The point, which moves between each measurement, is measured by an optical distance and angle measuring device which is placed each time in an arbitrary position in an earth-related coordinate system. The measurements of the position of said point are transformed from an earth related coordinate system to the object related coordinate system. By comparing the current measurement of the point with past measurements of the point, the wear on the surface of the object can be determined.

Abstract: A protective device is disclosed which is useful in protecting an operator against radiation emitted during welding. The protective device, which is employed in the presence of a surrounding light source, includes an interference filter which has a spectrally selective portion with bands for one or more of the ranges of wavelengths present in the emission spectrum of the surrounding light source and a radiation absorbing portion which attenuates the radiation to a value harmless to the eye without interfering with the spectrally selective portion of the interference filter.

Abstract: This invention relates to apparatus for removing nitrogen from air. A compressor forces the air into a bed which is capable of adsorbing nitrogen from the air and also removes gas from the bed by suction. The cylinder of the compressor communicates directly with the bed through a pipe which permits gas to flow freely in both directions and the bed communicates with the chamber for collecting the gaseous mixture from which the nitrogen has been removed. That chamber is connected to an outlet pump via a first controllable outlet valve while the end of the cylinder which is in direct communication with the bed is provided with a second controllable outlet valve. The nitrogen free mixture passes out through the first controllable outlet valve and the nitrogen passes out through the second outlet valve.

Abstract: A warning valve arrangement is provided in a breathing apparatus for divers. The breathing apparatus includes a breathing circuit which functions as a closed circuit during a rebreathing phase and a dosing or supply bottle which is alternately connected through a dosing valve to (i) a breathing gas container, from which the dosing bottle is filled, and (ii) the breathing circuit, into which the contents of the dosing bottle are discharged. The breathing circuit comprises a warning valve, which in a closed state at least obstructs inhalation from a breathing bag connected to the breathing circuit. A timing and pressure sensing control device is connected to a supply conduit which interconnects the dosing bottle and the breathing circuit, and, responsive to pressure variations in this supply conduit, causes the warning valve to assume the open state for enabling rebreathing in the breathing circuit.

Abstract: A method and apparatus for transferring liquid from a first vessel to a second vessel. The second vessel communicates with the first vessel at a location beneath the surface of the liquid contained therein and means are provided for passing vapor present above the surface of said liquid to a heating zone where the vapor is heated to a temperature above the boiling point of the liquid. The heated vapor is then contacted with the surface of said liquid by means provided therefor. As a result of said contact, the surface liquid is caused to boil, thereby increasing the pressure above said surface, this increased pressure causing movement of liquid from the first vessel to the second vessel.

Abstract: An arrangement for perforation a stripe of a ductile material such as plastics or a ductile metal such as aluminum or copper and for forming a lattice of the stripe comprises a preferably rotating cutting roll, which cooperates with a holding-up tool. The cutting roll has at least one axially aligned row of cutting plates. Each cutting plate has a cutting edge and a partly cylindrical part, which forms a part of the cylindrical mantle surface of the cutting roll. In cooperation with the holding-up tool the cutting edges of the cutting plates make a row of slots in the stripe, whereupon the walls of the slots are extended in the longitudinal direction of the stripe, while the partly cylindrical parts of the cutting plates hold other parts of the stripe against the holding-up tool so as to form a lattice without changing the width of the stripe.

Abstract: A device for measuring the radiation from an object by means of an optical system. The optical system comprises scanning devices for horizontal and vertical scanning with refracting rotating prisms. At least one radiation reference source is arranged in the optical system along the path of radiation from the scanned object so that the radiation source can be scanned by the rotating prisms at intervals which are not coincident with the interval when the object is scanned.

Abstract: Breathing apparatus is provided for use under water which comprises a connection device such as a helmet, mask, or the like and a breathing circuit in communication with the connection device. The breathing circuit includes a carbon-dioxide absorber and an expansible gas chamber, and, in operation, provides a first operating period wherein the breathing circuit is closed and a breathing gas is caused to circulate in the breathing circuit until the oxygen concentration of the circulating breathing gas is reduced to a predetermined value and a second operating period, which alternates with the first, wherein the used breathing gas is released to ambient and a fresh gas, the quantity of which is substantially independent of the depth of the user under the water surface, is applied to the breathing circuit.