Abstract: The invention relates to a collapsible core for a mould. The core comprises three relatively movable assemblies. The first assembly carries a cone, the second assembly carries an inner set of segments which form part of the core surface and engage the cone and the third assembly carries outer segments moved by inclined pins on the second assembly. As the assemblies are moved together the outer segments move radially outwards and the inner segments move axially in between them. Then the inner segments move radially outwards and the cone fills the center of the core. On reversal of the movement, the core is collapsed to enable it to be withdrawn from the moulded article.

Abstract: A method of detection of microbial growth which comprises preparing a culture of an organism, analysing a portion taken from the whole culture in a pyrolysis mass spectrometer, and monitoring the relative height of the peak in the mass spectrum corresponding to mass of 60 daltons, an increased height of the said peak relative to the remainder of the spectrum being indicative of growth of the microorganism.

Abstract: The invention relates to an intruder detector for use in a burglary in which infra-red radiation is imaged onto a sensor 16. The imaging system, which serves to divide the area of surveillance into monitored and unmonitored zones and to focus the radiation onto the sensor, consists of a window 12 constructed as a flat one-piece segmented Fresnel lens, each segment 12a, 12b and 12c focusing energy from a different respective monitored zone onto the sensor 16. The lens is double sided with one side acting as a convex lens and the other as a set of deflecting prisms.

Abstract: A circuit for generating a timing signal in a Manchester decoder comprises an oscillator 10, a frequency divider 14 for dividing signals derived from the oscillator, and a comparator 18 for comparing the times of transitions in the output signal of the divider with transitions in input Manchester data. To form a digital phase locked loop, gates 12 and 16 are provided for selectively adding a pulse to and subtracting a pulse from the pulses applied to the divider 14 by the oscillator 10 in dependence upon the relative timing determined by the comparator 18, in such manner as to lock the phase of the output signal of the divider onto the phase of the Manchester data. A squelch circuit is also provided for inhibiting phase control by the comparator 18 in response to a drop in signal strength of the received signal containing the Manchester data.

Abstract: An intra-ocular lens which is formed entirely of a polysulfone plastics material. This material is capable of being worked to produce a lens of optical quality, has a refractive index in excess of 1.55 and is capable of being autoclaved in steam at a temperature in excess of 110.degree. C.

Abstract: An electroacoustic transducer is provided in the form of a flexible tape formed of an inner flat metal foil 10 surrounded by a metal foil 14 and separated from the latter by an electret 12. The outer metal foil 14 is in turn surrounded by a PVC outer layer 20. This construction provides a flexible electret type of microphone with the additional advantage of immunity from ambient acoustic waves and electrical and magnetic fields.

Abstract: The invention relates to anterior chamber implants of the type having a haptic with feet resting on the anterior surface of the iris. To enable the implant to be autoclaved, the optic is made of glass and the haptic is separately formed from an autoclavable inert material. Titanium and a polyethersulphone thermoplastic material are disclosed as suitable materials for the haptic.

Abstract: Spring scissors are provided in which, in addition to the resilient means which provide jaw-opening bias, lateral-urging means are provided, which act on the handles of the scissors to produce or mechanically augment the cross-cutting pressure between the blades.

Abstract: A muffler for use with machines such as pneumatic drills consists of an elastomeric housing divided into an admission chamber and a series of muffler chambers. Within the housing are an inlet conduit communicating with the admission chamber and each muffler chamber, an exhaust conduit communicating with each muffler chamber as well as with a tail pipe outside the housing, and a Helmholtz resonator communicating with the admission chamber.

Abstract: An intraocular anterior chamber implant which can be used successfully in widths of 5 mm or less comprises an optic and a haptic which consists of a pair of bridging members each of which joins one of diametrically opposed edges of the optic to a support member. The support members each have a scalloped edge, whereby a pair of co-planar "U" shaped support surfaces is provided, and each bridging member has scalloped side edges to reduce its width relative to the optic.

Abstract: A bipolar electrode support structure for use in a lead acid battery is constituted by a porous matrix of valve metal, impregnated with lead or a lead alloy, and is provided on at least one surface thereof with a rim-portion at which little or no lead is exposed. The rim-portion is used to maintain an electrolyte-tight seal in operation.

Abstract: A copper-containing sulfidic material is dead-roasted at a temperature of at least 750.degree. C. and the resulting calcine is leached in a sulfuric acid solution to dissolve most of the copper in preference to any iron, nickel and cobalt in the material.

Abstract: Powder rolling apparatus, for the production of strip equal in width to the roll length, is provided with edge restraint devices in the form of cylindrical blocks mounted in the roll gap region with their axes parallel to the roll axes and rotatably driven to cause an end-face of each restraint block to move in frictional contact with the end-faces of the rolls.

Abstract: Use of a burner design featuring a tunnel of high length to diameter ratio enables the flash-smelting of sulfides to be carried out in a much more confined space than heretofore possible.

Abstract: A metal sorter including a pair of electrically conductive probes of identical metallic composition are placed in contact with a metallic specimen. A thermoelectric heat pump is positioned between the two probes to produce a temperature difference therebetween, a temperature sensing device senses the temperature difference and provides an electric signal to control the electric power supplied to the heat pump. A detection device provides an electric signal indicative of the potential difference between the probes.

Abstract: A process for separating nickel and cobalt present in a sulfate solution includes using a cationic extractant to extract both metals, treating the loaded cationic extractant with an aqueous chloride or thiocyanate solution to back-extract the cobalt and thereafter recovering the cobalt from the back-extraction aqueous solution by solvent extraction or ion exchange with an anionic extractant.

Abstract: A flash smelting furnace has an outer metallic shell from which portions are cut out to expose the outer surface of the refractory lining at a depth corresponding to the location of the matte-slag interface, and gaseous cooling jets are directed onto the exposed refractory lining.

Abstract: A sulfide containing copper and one or more of iron, nickel and cobalt, is dead-roasted at a temperature of 750.degree. C or above, then subjected to a pressure leach under reducing conditions to produce elemental copper and an aqueous solution of the other metals.

Abstract: A bipolar electrode support structure for use in a lead acid battery is constituted by a porous matrix of valve metal, impregnated with lead or a lead alloy, and is provided on at least one surface thereof with a rim-portion at which little or no lead is exposed. The rim-portion is used to maintain an electrolyte-tight seal in operation.

Abstract: A three phase mixture, of organic liquid, aqueous liquid and solid phases, is separated in a settler vessel equipped with means for imparting local agitation in the region of the aqueous/organic interface.