Abstract: Thermosetting resins selected from aminoplast, unsaturated polyesters, and cross-linkable high-vinyl polybutadienes and certain derivatives thereof (a thermosetting moulding material containing said resins) are modified by incorporation of up to 50% by weight (based on the total weight) of a low-vinyl polybutadiene or certain derivatives thereof.

Abstract: A method of and system for locating a position in which a plurality of frequency standard devices are synchronized or phase compared at the same initial location. Two of three frequency standard devices, in a two-dimensional embodiment, are placed at transmitting stations on a known baseline. The third device is at a (third) receiving station, which receives signals from the two transmitting stations. At each transmitting station, means are provided for producing and transmitting a different radio frequency carrier signal of fixed frequency and of fixed phase, phase modulated by a periodic modulating signal in the form of a time signal produced under the control of its frequency standard device. At the receiving station, means are provided for producing a reference signal corresponding to the periodic modulating signals and two radio frequency signals related in frequency, to the radio frequency carrier signals transmitted.

Abstract: A method of reducing the transmission bandwidth for television pictures is described in which the frame is divided into at least three fields each consisting of picture information from an apparently random distribution of picture elements and the transmitted signals are obtained by sampling the video output of a line scanned television camera as the scanning spot passes each of the picture elements. Usually no picture element will be sampled more than once during the formation of a complete frame and therefore each line scanning field contributing to the picture will consist of information from a different set of randomly distributed elements.

Abstract: A pulse Doppler radar utilizes a rapidly switched pulse repetition frequency, and is provided with a pulse integrator arranged to commutate at the prevailing pulse repetition frequency. By this means ambiguities in the Doppler frequency shift relating to range can be removed.

Abstract: A co-axial line to waveguide junction is formed from a length of waveguide with a co-axial line section along the length with the center conductor of the co-axial line entering the interior of the waveguide length. Connecting means are provided at each end of the length to enable connection of selectably short circuiting means. When any of the short circuiting means is in the short circuited state, a path is created between the co-axial line section and the other end of the waveguide length.

Abstract: Elevating means for use with a wheelchair said means being adapted to be secured to the side frames of the wheelchair and having hydraulically actuated lifting means which when operated extend downwardly to engage the ground and lift the side frames of the chair upwardly.

Abstract: This disclosure relates to a device for centering a V-block relative to a tool which is to perform a machining operation on a workpiece to be mounted in the V-block. The center finder is in the form of a block contoured to seat in the V-block and having formed in the upper surface thereof grooves of a width corresponding to various machine tool widths so as to effect the centering of the center finder block relative to the tool which, in turn, automatically centers the V-block relative to the tool.

Abstract: A photo-conductive target pick-up tube has a vacuum sealed envelope housing a tubular anode electrode on the gun cathode side of the target. The anode electrode is roughened on its inner surface to provide light scattering from a lamp which is mounted in a cavity protruding into the envelope but which cavity is sealed from the vacuum inside the envelope. The lamp is mounted on the longitudinal axis of the axis so as to provide an artificial dark current which tends to reduce build-up and decay lag at low light level operating conditions.

Abstract: A vehicle location system for vehicles travelling over a predetermined route in which equipment in the vehicle derives information concerning the distance travelled from predetermined junctions and the turns made and computing means within the vehicle computes the route between road junctions on which the vehicle is travelling. Each vehicle carries transmitter means for transmitting computed location information to a base station when interrogated by the same.

Abstract: The invention relates to a method of correcting errors, particularly double adjacent errors, which occur in a transmission path of a data handling system. A family of error correcting codes can be used to provide a similar correcting power for such errors as conventional BCH codes have for single random errors. The invention is applicable to transmission systems in which data is present in the form of a sequence of fixed length blocks.

Abstract: A switching arrangement for use at very high frequencies (gigahertz) consists of a number of four port microstrip switches interconnected to provide a versatile routing matrix. The use of P.I.N. diodes in each switch provides low insertion loss and also high isolation between different routes. The arrangement can be made in a very compact form.

Abstract: This invention relates to a so-called live anchorage for use in the prestressing of concrete structures, the stressing element being anchored in a hole having a frusto-conical portion and a cylindrical portion by means of a frusto-conical wedge device, the leading or narrow end of said wedge device being such that it extends into said cylindrical portion.

Abstract: Spectrometric gratings formed by holographic techniques are disclosed. The gratings are employed in monochromator mounts of the type in which fixed entrance and exit slits are combined with simple rotation of the grating to scan the spectral range of interest, the angles of incidence and diffraction and the positions of the slits being so related that the mounts are characterized by improved optical performance due to phase balancing and improved focussing properties according both to geometrical and diffraction theories. The parameters involved in the holographic formation of the gratings, specifically the angularities and positions of the point sources forming the holographic image of the grating lines, are specifically related to the characteristics of the mount as to improve further their optical characteristics, particularly with respect to mounts either employing "normal" (i.e., relatively small) angles of incidence with large grating apertures or employing grazing incidence (i.e.

Abstract: A bone implant for attaching fibrous connective tissue such as a tendon or ligament, either artificial or natural, to bone, which comprises a tapered porous plug, preferably of sintered metal; a tendon prosthesis having such a plug at its distal end is also disclosed.

Abstract: Improvements in a gas generator having a "rambine" rotor on which compression, combustion and expansion take place. The improvements include a counter rotating compressor rotor with blades shaped to impart a component of velocity in the direction of rotation of the compressor rotor, hence increasing the whirl velocity of inlet air to the rambine rotor.Preferred embodiments include a plurality of compressor rotors for successively increasing the relative whirl velocity; a rambine rotor having a combustion zone with increasing cross-sectional area over an ignition delay distance for obtaining higher heat release using a weaker shock wave; a zero work rotor with sets of blades spaced by an annular combustion chamber; an ignition stabilizer and starting nozzle arrangement, and apparatus for controlling the gas generator over a range of power settings.

Abstract: A method of making a pyrolytic graphite grid electrode for a high power transmitting tube includes the steps of holding a metallic grid electrode core between two copper blocks, heating the core to 1750.degree.C by passing an electric current through it and passing a carbonaceous gas over the heated core so that graphite is deposited thereon.Because the graphite thickness is reduced towards the copper blocks supporting the core, where the grid is to be used in a high voltage tube annular shields are provided around the supported ends of the grid.

Abstract: A so-called dead end anchorage assembly for use in prestressing concrete structures which comprises a frusto-conical element received in a correspondingly shaped hole in combination with a stop element fixed to a stressing element to engage one end of said frusto-conical element. Further, said hole has a frusto-conical portion and a cylindrical portion, and the narrow or leading end of said frusto-conical element extends into said cylindrical portion.

Abstract: A toy comprising a base and means on the base rotatably mounting a plurality of pinion wheels in interengaging relationship one with another so that different patterns of the pinion wheels may be created.

Abstract: A method of treading or re-treading tires involves compression of the wearing surface of the tread. A tread strip, which may be an annular band, is compressed in a direction parallel to its longitudinal axis and is bonded to a tire carcass, while being maintained under compression. This may be done by compressing a tread band into an undersized mould; apparatus for assisting this is also described. Alternatively, the tread strip may be of finite length, for example to form a lug, in which case the strip is formed with a radius of curvature less that of the surface to which it is to be applied, so that the convex (wearing) surface of the strip is compressed upon application to the carcass.

Abstract: A mobile stone crushing machine comprising a chassis on which is mounted a stone crushing unit and endless conveyor, a front end of which is adapted to collect stones from the ground as the machine is advanced over the ground, and from which the stones are continuously discharged into a stone crushing unit, characterized in that the stone crushing unit includes two crushing zones, each of which incorporates at least one crushing roller, so arranged that the stones to be crushed first pass through a nip associated with the roller at the first zone and on discharge from this nip the partially crushed stones and other matter then pass through a nip associated with the roller at the other zone. Preferably, the two crushing zones are arranged one above the other and each incorporates a pair of crushing rollers, one of which is rotatable about a fixed axis and driven and the other of which is supported upon a pair of trailing swing arms.