Abstract: An active sound control system is described in which allowance is made in a relatively uncomplicated circuit for acoustic coupling between a sound generating system for generating a cancelling sound wave and a detector for sensing a sound wave to be cancelled. Unwanted sound from a source is detected by a microphone and cancelled by sound from a speaker connected by way of an amplifier to the microphone. The amplifier has a feedback processing system with a transfer function which takes account of acoustic feedback between the speaker and the microphone in deriving, with the amplifier, a signal to drive the speaker.

Abstract: A method of automatically controlling the production of a weld bead including examining with reflected ultrasound from one surface of a piece of material the position of a weld pool on the material and the position of another surface of the material, and controlling the position of the weld bead on the material from the result of said examination.

Abstract: In order to provide for lengthening of a long bone, such as in place of natural growth, an endoprosthetic device (10, 20) is provided in a two-part telescopic form defining a longitudinal passageway (15) in which ball bearings (40) are progressively locatable to control adjustably the device length. At least one end (24) of the device will be adapted for securement in the bone, and the other end (11) can be similarly adapted or define an articulation surface for a joint. The telescoped parts are preferably mutually keyed (22, 23) against rotation, the passageway is preferably of like cross-sectional form as the ball bearings so that the latter form a singular sequence therein, and the ball bearings are suitably located by way of an acutely inclined branch passageway (17).

Abstract: A pelvic belt (10) to be worn by a patient whereby tension lines are connectable for the application of tractive force is provided with four pocketed zones (13) or so-called ilia crest sections therealong and two tension line connectors (20) respectively located adjacent alternate ones of said zones.

Abstract: Compounds which are a 1-hydroxypyrid-2-one in which one or more of the hydrogen atoms attached to ring carbon atoms are replaced by a substituent selected from aliphatic acyl, aliphatic amide, aliphatic amine, carboxy, cyano, aliphatic ester, halogen, hydroxy and sulpho groups, alkoxy groups and alkoxy groups substituted by an alkoxy, aliphatic amide, aliphatic amine, aliphatic ester, halogen or hydroxy group, aliphatic hydrocarbon groups and aliphatic hydrocarbon groups substituted by an alkoxy, aliphatic ester, halogen or hydroxy group, but excluding compounds in which said replacement of hydrogen atoms in the compound is effected only by substituents selected from aliphatic hydrocarbon groups, halogen groups and aliphatic hydrocarbon groups substituted by a halogen group, or a salt thereof containing a physiolgically acceptable ion or ions, are of value in the treatment of patients having a toxic concentration of a metal, particularly iron, in the body whilst the iron complexes of such compounds are of val

Abstract: Pharmaceutical compositions containing a 3-hydroxypyrid-2-one or 3-hydroxypyrid-4-one in which the hydrogen atom attached to the nitrogen atom is replaced by an aliphatic acyl group, by an aliphatic hydrocarbon group, or by an aliphatic hydrocarbon group substituted by one or, except in the case of ionizable groups, more than one substituent selected from aliphatic acyl, alkoxy, aliphatic amine, aliphatic amide, carboxy, aliphatic ester, halogen, hydroxy and sulpho groups and, optionally, in which one or more of the hydrogen atoms attached to ring carbon atoms are replaced by one of said substituents, by an aliphatic hydrocarbon group, or by an aliphatic hydrocarbon group substituted by an alkoxy, aliphatic ester, halogen or hydroxy group, but excluding compounds in which said replacement of hydrogen atoms in the compound is effected only by aliphatic hydrocarbon groups, or a salt thereof containing a physiologically acceptable ion or ions, are of value for removing toxic amounts of metals, particularly iron,

Abstract: An apparatus and method for detecting the direction of a sound. A thin shell structure is permitted to flex in response to incident sound and perturb the form of the shell. The perturbation is detected and from this the direction of the sound can be determined.

Abstract: In a process for making metal strip 7, a spray 9, 10 of molten metal is directed towards a nip 13 formed by two smooth cooled rolls 6, the rolls being rotated so that the nip hot-compacts the sprayed metal to yield a strip emerging from the exit of the nip. Splats formed by droplets of the molten spray impinging on the rolls 6 before reaching the nip 13 do not stick completely to the roll surfaces but at least partially detach themselves on freezing and form a new surface on which subsequent droplets of the spray land; when the nip is reached, the partially detached frozen droplets and their overlying deposit, on both rolls, are compacted hot.

Abstract: A balancing system for use in for example a motorcycle engine to balance forces generated by a piston and connecting rod arrangement connected to a crankshaft. The crankshaft supports a first gear meshing with a second internal gear supported by an intermediate member such that the intermediate member rotates in the same direction as the crankshaft. The intermediate member supports a third external gear driving one or more balance shafts. In a single balance shaft arrangement, the external gear drives the balance shaft directly. In a twin balance shaft arrangement, the external gear drives one of the balance shafts directly and drives the other balance shaft via a further gear supported by a further intermediate member.

Abstract: A solid titanium alloy comprises Ti+Co+Cu+ optionally other elements. The titanium is from 95 to 40 wt. %. The liquidus is below 1300.degree. C. and the structure is of small equiaxed high-melting grains surrounded by at least 10 vol. % of low-melting material. This structure is achieved by vigorously agitating the alloy between its liquidus and solidus so as to break up dendrites, and thereby permits the alloy to be subsequently thixocast.

Abstract: A device is proposed comprising a main support structure (10) and associated bone pins (32-36), each pin having leading and trailing treads (36, 34) of the same hand and pitch but with the latter thread of larger diameter to engage any one of a plurality of like threaded bores (19) through the main structure. Preferably the main structure includes an elongate frame (11) of closed loop form with a separable end (15) and two slide plates (12) mounted therein in adjustable end-to-end relation, each plate having at least two bores in an overall array orthogonal of the plates and longitudinal of the frame. The device also preferably has a cap (37) to cover the exposed trailing ends of the pins. The device is particularly useful in dorsal application for finger bone fracture fixation.

Abstract: Sorting apparatus conveying articles through an inspection station includes an operator manipulated indicator which cooperates with an orthogonal sensing matrix beneath the conveyor to provide position and article size information used to selectively actuate deflection fingers to deflect an indicated article.

Abstract: A root crop harvester includes an endless soil-separating conveyor-sieve and agitator means for agitating the conveyor-sieve so as to move to and fro the crop-bearing upper run of the conveyor-sieve substantially in the plane of said upper run.

Abstract: A device for focussing or collimating a beam of acoustic radiation comprises a body of acoustically transmissive material having first endface (12) coupled to a source of acoustic radiation (16, 18). The radiation is internally reflected by the side surface 20 of the body, this surface being of a shape such that it brings the radiation to a focus F after transmission through a second surface (14).

Abstract: A variable characteristic filter is described in which output signals are frequency analyzed by means of a frequency-to-voltage converter to derive a control signal. Variable impedance elements in the filter are controlled by the control signal to vary the filter characteristic automatically. The filter, including the frequency-to-voltage converter, may be such that the filter attenuation is reduced in the frequency region where the input or output signals mainly occur. The invention is particularly useful in Doppler blood-flow velocimeters to reduce noise.

Abstract: The invention provides a digital data processor which has been systemetized down to bit level. The processor includes a regular array of identical processing cells which perform a logic operation on incoming bits. The cells repeatedly perform a cell operation under the control of clocks which govern the inputting to and outputting from the cell of data bits. Each bit takes part in a maximum of one cell operation in one repetition of the clock having the highest repetition frequency.Processing cell arrays for dealing with larger numbers may be readily built up from smaller arrays used for smaller numbers.Having obtained a fully working design for one type of processing cell, the full array consisting of a plurality of cells is proven.

Abstract: A non-rigid bone fracture fixator comprising first and second bone pins for connection either side of a bone fracture and primary and secondary supports clamped to the bone pins by respective fixed and guide clamps. The second support and the guide clamps are connected slidably to the primary support such that the supports may execute a controlled degree of movement with respect to one another. A compression spring is arranged to bias apart the supports longitudinally of a fixated limb. In use the fixator is applied to the limb with the fracture in slight compression. Exercise of the limb then produces varying degrees of fracture compression stimulating bone callus formation and rapid healing. The fixator may include actuating means to provide passive fracture exercise for immobilized patients.

Abstract: A transducer with which mechanical rotary motion can be interconverted with the flow of an electro-rheological fluid. Two, electrically conductive, movable, conveying surfaces are partly disposed in parallel confrontation thereby defining a fluid transfer path. A fluid transfer port is located at each end of the fluid transfer path through which electro-rheological fluid can enter and leave the transducer. The conveying surfaces are electrically connected to a voltage source and movable by means of a rotor to which they are connected. On application of a voltage difference between the conveying surfaces the electro-rheological fluid gells after which rotation of the rotor will urge the fluid along the transfer path and vice-versa.

Abstract: An electroviscous (EV) fluid composition whose fluid properties are altered in the presence of an electric field comprises water-containing particles of a phenol-formaldehyde polymer dispersed in a non-conducting liquid. The composition, selected from the broad range of fluid compositions of UK Pat. No. 1570234, possesses improved fluid properties combined with markedly reduced electrical conductivity, and is thus more suitable for use in applications such as at the interface between electronics and power hydraulics for example.In a preferred embodiment of the present invention the polymer comprises the dilithium salt of 2,2', 4,4' tetrahydroxybenzophenone condensed with formaldehyde, dispersed at 30% V/V in a mixture of brominated diphenyl methane (BDM) liquid components having the averaged formula C.sub.6 H.sub.4 Br.CH.sub.2.C.sub.6 H.sub.5.

Abstract: In a potentiometric chart recorder, the speed of the chart motor 22 is, in one mode of operation (AUTO) selected by a switch 32, varied between two values in dependence upon the rate of change or slope of the input signal at 10 as detected in a detector 30. The slow speed is obtained by intermittent operation at the fast speed, and during the non-operative periods power-consuming circuitry e.g. 16, 18, 26 is switched off by a switch 40.