Abstract: A positioning device, particularly applicable to positioning a visor on a helmet comprising a clutch output member, a datum member, and a clutch input member, the output member constrained to move along a particular path with respect to the datum member, usually an arcuate path, and the output member containing the input member and detent members at either side of the input member which lock the output member to the datum member until released only by movement of the input member which drives the output member to another locked position.

Abstract: An electrothermal thruster includes an electrical heater comprising a copper pipe surrounded by a co-axial tubular copper jacket, and a resistance heated chamber cooperating to heat and decompose liquid fuel which flows into the pipe to effect a gaseous discharge through a propelling nozzle. The jacket has a closed end soldered to the pipe which is supported from the open end by wires. The pipe, jacket and wires constitute the secondary winding of a transformer. The primary winding is of toroidal form round an annular core disposed co-axially about the pipe within the jacket. Induced current in the secondary causes heating of the pipe in turn heating fluid therein.

Abstract: A code synchronizing apparatus for synchronizing a local pseudo-random binary-sequence code generator with signals of a pseudo-random binary-sequence carried on incoming signals from a remote source, includes a sampler for obtaining sequences of samples of an input signal and of local code signals from a signal generator, a correlator for correlating the sequences of samples with those of local code signals which are offset by different integral numbers of bit-periods from a sequence of local code signals produced while the input signals were being sampled, an adder for summing the correlation values for each offset, means for identifying the offset which produces the maximum summation of correlations, and a correlation counter for correcting the timing of the local code generator by an amount dependent on the magnitude of the offset so identified.

Abstract: An automatic radio direction finding method and apparatus which employs a scanning directional wide aperture aerial system, a receiver, and a computer which effectively simulates the methods of a skilled direction finding operator in determining the direction of arrival of a radio wave using all the pattern information derived from the aerial system. A representation of the amplitude distribution of the receiver output signal as a function of the direction of maximum sensitivity of the scanning aerial system is stored, and the computer then determines the point about which this distribution is most symmetrical using an algorithm which folds the distribution, in sampled data form, in half, and computes the sum of the difference amplitudes between the overlaid samples.

Abstract: An acoustic wave device employing surface skimming bulk waves comprises a piezo electric substrate having a flat surface which carries an input transducer and an output transducer for respectively lanuching and receiving acoustic waves into and from the bulk of the substrate. The substrate may be of quartz, lithium tantalate, or lithium niobate and has the flat surface orientated so that a surface skimming bulk wave is launched without generation of surface acoustic waves.

Abstract: A process for coating an article such as a turbine blade composed of nickel-base alloy, comprises the steps of surrounding the article by a particulate pack in a chamber, the pack including coating material in elemental or chemically combined form, said coating material selected from the group comprising aluminium, chromium, titanium, zirconium tantalum, niobium, yttrium, rare earth metals, boron and silicon together with a halide activator, preferably of low volatility, and cyclically varying the pressure of an inert gas or a reducing gas or a mixture of said gases contained within said chamber, while maintaining the contents of the chamber at a temperature sufficient to transfer coating material onto the surface of the article and form a diffusion coating thereon.

Abstract: An infra red transmitting glass has up to 30 atomic percent of telluride substituted for selenide in a glass within the following range:Germanium: 10-35 atomic percentArsenic: 9-45 atomic percentSelenide: 45-70 atomic percentThe glass may be formed into infra red lenses or formed into infra red transmitting fibres using two slightly different glasses from the above range for the core and cladding of each fibre.

Abstract: The present invention discloses chiral thermochromic liquid crystal mixtures which do not contain cholesterol or sterol residues.

Abstract: Apparatus for supplying a mixture of oxygen and air for respiratory purposes and comprising a supply regulator having a first chamber with an inlet and an outlet for oxygen and a second chamber with an inlet and an outlet for air, control means responsive to a higher pressure in said first than said second chambers to permit air to enter said second chamber, adjustment means for modifying the action of said control means, first and second restrictors in the first and second outlets respectively, the second restrictor bore being larger than that of the first, said first and second outlets leading to a common supply duct and then to a first demand regulator responsive to an inspiration pressure drop to permit a flow of gas therethrough.

Abstract: A dye compound suitable for use in solution with a liquid crystal material is characterized by one of the following formulae: ##STR1## (III) a derivative of (I) or (II) containing one or more simple lateral substituents or bridging groups on the benzene rings: ##STR2## where n.sub.1, n.sub.2, n.sub.3 are integers in the range 0 to 4, A is azo or azoxy, X is cyano, or nitro and Y.sub.1 and Y.sub.2 are one of the following: hydrogen, alkoxy, arylalkoxy or N.sub.R.sbsb.2.sup.R.sbsp.1 where R.sub.1 and R.sub.2 are alkyl, substituted alkyl or alkylene groups.

Abstract: An Electrolytic cell having a separator positioned between a positive electrode and a negative electrode is disclosed in which the separator is a moulding of polymer material derived from a particulate polymer material having a polar graft-copolymerized surface. The separator may be deposited as a coherent film of the surface of an electrode by sintering the particulate material into a coating around the electrode using heat and/or pressure. Alternatively a shaped article such as a case, envelope, sheet film or the like may be prepared and used to wrap around or encase an electrode.

Abstract: This invention provides an improved reinforcement for a bridge span, the reinforcement including a reinforcing member for attachment in an underslung position to the span, a reinforcing strut adapted at its first end for pivotal connection to a point intermediate the ends of the reinforcing member and jacking means for urging the reinforcing strut into its working position in which the reinforcing member is under tension. The improvement resides in that the jacking means is adapted to be mounted upon the bridge span and, in use, exerts a force transverse to the longitudinal axis of the strut to urge it into said working position in which the strut is, at its point of connection to the member, inclined at acute angles to the member.

Abstract: A method of treating a hydrophilic polymer film is described in which the film is immersed at a temperature greater than 80.degree. C., and preferably greater than the crystalline melting point of the polymer, in a liquid capable of swelling the polymer. Polymers to which this method can be applied include graft copolymers of for example polyethylene, polypropylene, polytetrafluoroethylene, and nylon with acrylic or methacrylic acid. The films when treated have decreased electrical resistance and increased hydroxyl ion permeability and are then useful as battery separators and in other semi permeable membrane applications.

Abstract: Apparatus for use in compensating for gun sighting errors due to misalignment between the muzzle axis of a gun and the optical axis of an associated gun sighting system is described, comprising a marker and a collimator mounted on the gun remotely from the muzzle and in fixed relation to one another, a reflector fixed to the muzzle portion of the gun barrel so as to be capable of reflecting into the collimator an uncollimated marker beam emanating from the marker, and means for defining an initial coincidence mark whose position is fixed in relation to the said optical axis so that after leaving the collimator the reflected marker beam can form a marker image superimposed upon the said initial coincidence mark, whereby any subsequent deviation of the muzzle axis from the said optical axis results in a corresponding movement of the marker image away from the initial coincidence mark.

Abstract: The invention concerns an edge connector for mounting on the edge of flat panel displays, e.g. liquid crystal or electroluminescent display panels, arranged in matrix format. The edge connectors have mounted therein drive electronics, e.g. serial input parallel output shift registers. Two series of conductors are carried by the edge connector body, one series of conductors connect with external control circuits and the other series of conductors connect with addressing electrodes on a display panel. Faulty drive electronics are easily replaced by unclipping the edge connector from the panel and substituting a new edge connector complete with new drive electronics.

Abstract: A display comprises a plurality of addressable display panels each having a display zone for displaying visual information and arranged in a formation so as to collectively provide a composite display of increased area. A fibre optic image transform construction is arranged in front of the display panels for transforming an image collectively provided by the panels into a corresponding continuous image in which discontinuity between adjacent panel display zones is eliminated.

Abstract: A filament-reinforced resin-impregnated hollow body having at least one internal circumferential strengthening flange or rib is fabricated by winding a first filamentary winding on each of two mandrel portions, the filament being wound across at least one end of each portion so that the winding extends inwards towards the axis of each mandrel portion. With these two ends spaced opposite one another, a second filamentary winding is wound between the inwardly extending parts of the first winding. A third winding is then applied over the first and second windings. After curing the resin-impregnated windings, the mandrel is removed, leaving an internal flange formed by the inwardly extending parts of the first winding in conjunction with the second winding.

Abstract: A d.c. electroluminescent panel comprises a transparent substrate, a transparent first electrode film, a phosphor layer, and a second electrode film. Application of a voltage across the phosphor layer causes it to emit light.In this invention the phosphor layer is produced in two layers, a first semi-insulating thin layer of activator doped phosphor and a second electrically conducting layer of phosphor.

Abstract: Apparatus for transferring electromagnetic signal energy between a signal circuit and an antenna that extends outwardly from a ground-plane surface includes a conductive shield that substantially encloses the antenna to confine the signal energy and to exclude all others. The shield has an open end to admit the antenna and suction-cup means disposed around the opening to mechanically connect the apparatus to the surface. A plug of dielectric material inside the open end includes a through passage and a recessed portion that conforms to a base of the antenna and operates to align the antenna within the shield. Conductive mesh lines the recessed portion and is electrically connected to the shield. Flexible contacts extend inwardly from the shield and engage mounting screws in the antenna base to electrically connect the shield to the surface.

Abstract: A flotation stole having a chest portion of greater capacity at one side than the other so that it will invert an unconscious wearer who is face down in the water, even though the wearer may also be wearing clothing and an immersion suit and the stole being disposed to be symmetrical below the water level to ensure that the wearer may then lie in a substantially symmetrical configuration when face up in the water, that is without one shoulder being lower than the other.