Abstract: The invention provides a surveillance arrangement, and in particular an airborne surveillance arrangement, in which a television display of a scene is brightened up, by means of infra-red detectors, to emphasize heat emitting targets.In one example of airborne surveillance system, a linear array of infra-red detectors is arranged to view part of a scene viewed by a television camera, with the same horizontal field of view at a desired target range. In front of the array of detectors a light chopper is provided so that the output of each detector is a modulated carrier. The output of each detector is applied to a store, via individual impedance transformers, narrow bandpass filters and demodulators. Between each demodulator and the store, individual sharp out-off low pass filters and threshold detectors may be provided to provide a degree of discrimination against spurious responses.

Abstract: The invention provides a focalization process of spherical concave diffraction gratings, working by reflection for the dispersion of various radiations constituting a polychromatic light, in which fixed entrance and exit slits are used and in which only a certain rotation is imparted to the grating, the rotation is imparted to the grating in such a way as to make the radiations move in the exit slit. For a certain ruled width of a given grating and a given resolution, the sum of the object and image tangential focal length equations has a value .epsilon. different from zero and determined in function of the aberrations furnished by a concave grating corresponding to the retangular port.

Abstract: An early strength hydraulic cement comprising 7 to 90 per cent C.sub.12 A.sub.7 formed in an underlimed clinker burned to a low free lime, the underlimed condition being at least counterbalanced in the cement by a substance effective to raise the basicity.

Abstract: Automated apparatus for shaping the beaks of young fowl and simultaneously giving them an oral injection. A backing member is mounted for generally horizontal arcuate movement and a red-hot blade is mounted for generally vertical arcuate movement. The upper half of the fowl's beak is put on the top of the backing member which is urged forward by force exerted on the fowl's body. A pneumatic circuit is controlled by this forward movement and actuates a pneumatic jack which moves the blade downward clamping and cutting the fowl's beak at least partially. With the downward movement of the blade an injection gun may be triggered and compressed air injects a vaccine into the fowl's oral cavity through suitable apertures in the backing member. Compressed air is also carried through the backing member to blow away severed bits of beak. After a predetermined interval the pneumatic circuit returns the blade to its initial position.

Abstract: An early strength hydraulic cement is disclosed in which a clinker rich in C.sub.12 A.sub.7 and poor in CA or C.sub.3 A interground with Portland cement clinker, the resultant early strength cement including at least 10% by weight of C.sub.12 A.sub.7 with a majority of the balance being calcium silicates and including at least 10% by weight of C.sub.3 S.

Abstract: A friction brake includes a clutch device operable to connect friction plates to a rotary shaft so that they rotate with the shaft when the brake is to be operated by engaging said friction plates with a set of stator plates interleaved therewith.

Abstract: The invention provides a tracked air cushion vehicle comprising a vehicle body, a lift platform from which the vehicle body is suspended, end bogies provided at each end of the lift platform, the lift platform and the end bogies being adapted to run within an inverted channel section track so as to define a chamber which can be maintained at subatmospheric pressure, apparatus connected to the chamber for providing the sub-atmospheric pressure, and biasing apparatus coupled between the vehicle body and the end bogies for biasing the end bogies towards the roof of the track, the biasing apparatus exerting a force equal to at least a substantial portion of the weight of the end bogies.

Abstract: Apparatus for distributing power from a single alternating current supply to a plurality of loads having individual switches or thermostats comprises triacs placed in series with each of the loads, a generator to generate a continuous series of firing pulses timed substantially to coincide with the zero crossing points of the alternating current supply which pulses are utilized to fire the triacs and control logic operative to direct immediately suceeding trains of the firing pulses to switch on different triacs for successive integral numbers of half cycles of the supply in accordance with a continuous programmable sequence, the control logic being programmed in accordance with the condition of the individual switches or thermostats associated with the loads and advanced through its sequence by a clock generator preferably driven or synchronized by the supply frequency.

Abstract: A snubber for interpositioning between a substantially vertical surface on a transporting vehicle and an end member of a transported vehicle carried by the transporting vehicle comprises two elements, viz,: a first element for being secured to said substantially vertical surface on the transporting vehicle, and a second element mounted on the first element for cushioned vertical movements relative thereto, the second element having a substantially vertical surface engageable by the end member of a transported vehicle. Relative vertical movements between the transporting vehicle and the transported vehicle are accompanied by vertical movement of the transported vehicle end member substantially in unison with said second element, thus preventing undue rubbing of the end member on the snubber.

Abstract: A processor equipment has an input highway connected to receive a multiplex signal from a number of peripheral devices such as multiplex units time division multiplxing telephone handsets. A counter is arranged to scan the devices for a processor interrupt signal and upon the occurrence of such a signal the counter is inhibited to enable the processor to take the appropriate action for the interrupting device, e.g. apply a dial tone. If one of the peripheral devices becomes faulty a store memorizes the fact that on a previous scan the device produced a non-valid interrupt signal and causes the address of a predetermined other peripheral device to be written into the counter at which scanning is to recommence.

Abstract: This disclosure relates to a construction in a printer of the type utilizing an endless character-bearing band which is carried in a cartridge and which is mounted in the printer on two pulleys in a tensioned state, the construction including means for changing the spacing of the two pulleys only after a cartridge has been placed within the printer with the means being in the form of a key which rotates a cam and which key has associated therewith means for moving a protective member relative to the band when the key is in an operative position. The construction further includes locking means for preventing the insertion of the key into an operative position until such time as a cartridge is in position and the cover of the printer has been closed.

Abstract: An LED display is provided with a reflective surface over those parts of the display which do not themselves emit light. This enables a polarizer to be used to enhance the display contrast under conditions of bright ambient light.

Abstract: A method of producing book covers, which method includes cutting at least one elongated notch along the length of one side of a sheet of comparatively rigid plastics having a "memory" (as herein defined) and stretching the plastics defining the floor of the notch to alter its molecular structure so as to provide a readily foldable hinge, said stretching being effected by pressing the plastics defining the floor of the notch outwardly from the notch to raise a ridge on the other side of said sheet.

Abstract: A method of operating a storage tube having a secondary electron emissive storage target includes applying selected bias voltages to the target during the writing and erasure steps to control the electron emission ratio, which during writing is less than unity and which during erasure is greater than unity.This permits the voltage on the target during writing to be of the same order as the voltage present during reading, and this enhances the resolution and performance of the tube.

Abstract: A tracked air cushioned vehicle system comprising an inverted channel section track and a vehicle body suspended from a lift platform guided by end bogies. The platform and bogies define a chamber with the track, which chamber is maintained at subatmospheric pressure. The chamber is divided longitudinally into two separate subchambers, the dividing member including sealing members cooperating with the track and a gravitationally displaceable member is provided which is responsive to any lateral force exerted on the body except those due to centrifugal action, to cause a differential pressure between the subchambers for causing a rolling moment to be applied to the platform to counteract the lateral force. The dividing member may include a longitudinal flange depending from the roof of the track or a beam extending between the bogies and a flexible member extending longitudinally of the platform between the beam and the platform.

Abstract: A process of treating kiln flue dust from Portland cement manufacture which comprises calcining said flue dust together with a minor proportion by weight of a fluoride salt.

Abstract: A setup for use in a press for cold-forming metal parts, such as tripods of universal joints having a central body and radially projecting portions, from a cylindrical billet. A first setup is provided for forming an intermediate workpiece which may then be finished in a second setup. In the first setup the die sectors which make up the die are mounted on rams which are slidably mounted on slotted members between a spaced apart position when the press piston is in its raised position and a clamped together position by means of a toggle mechanism. Punches are provided on the table and the piston which compress the starting billet thereby extruding the metal into channels in each of the die sectors. In the second setup upper and lower die halves are carried respectively by the piston and the table of the press. The die halves have channels adapted to receive the various portions of an intermediate workpiece.

Abstract: A supporting collar for attachment to a tubular scaffold member having four radially disposed channel-shaped support brackets, said brackets being interconnected so that the open ends thereof are disposed about a circle. Said collar is formed in two hingedly connected parts, the free ends of said two parts being connectible by a nut and bolt device.

Abstract: A display device for portraying a scene having a foreground and a background, comprising a base board, one or more background replicas, shaped and designed to fit onto the base board and to represent a background, and one or more foreground replicas, each of the replicas being interchangeable with alternative designs of replicas, and wherein the replicas are arranged to be magnetically attached to the base board.

Abstract: A television camera arrangement includes a read only memory for storing character or symbol information in a form which can readily be combined with normal video picture information to produce a composite display. For example a symbol indicating the identity of a camera can be included in its video output.