Blade deflection monitoring allows unmanned sawing of super-hard alloys

international Diamond cleaving the preferred fibre optic connection method The move to fibre optics in telecommunications and data transmission has evoked a corresponding interest in establishing an optimum method of fibre-to-fibre connection. Of the options favoured, a strong candidate is a mechanical connection between two diamond-cleaved, optical fibre facesseveral companies in Europe, Japan and the USA manufacture purpose-designed devices to provide the high precision cleaved faces required. The Optall Division of the French Radiall Company produces a machine which cuts fibres of eight different diameters, with or without protective plastic sheath. At the heart of the machine is a high-quality, inclusion-free natural diamond which provides the means of indenting the fibre,

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thereby inducing a short precursor crack. The scored optical fibre is then pulled off its axis until it fractures. The diamond is a De Beers natural stone of 0.2-0.25 carats, set in a sintered bronze matrix; polishing is carried out to achieve specified, knife-edged geometry with a slight radius at the cutting edge. De Beers: Charters, Sunninghill, Ascot, Berkshire SL5 9PX

Blade deflection monitoring allows unmanned sawing of super-hard alloys A CNC bandsaw from Addison Tool, installed at Maher, is believed to be the first in the U K with a facility for monitoring blade deflection during operation. Until now, it has been necessary for an operator to be in attendance when cutting expensive alloys, as the presence of hard spots in an already very tough material can cause the blade to run off course. But the 241/S has full computer control, enabling any number of components to be produced in up to 99 different lengths in automatic cycle from one program. To avoid stopping the machine unnecessarily should deflection be only momentary, the deflection must be

sustained for one second before the machine is shut down. An L E D display on the control panel not only displays the amount of deflection in hundredths of a millimetre, but also indicates the direction of deflection and preset maximum. Addison Tool: Westfields Road, Acton, London W3 ORE.

Computer-controlled NDT technique branches out Quality control inspection using ultrasonic immersion techniques developed primarily for aerospace applications is now available for examining engineering materials in industry by companies with no previous experience of nondestructive testing. Utilising a microprocessor-controlled scanning system, developed as a standard package by Wells Krautkramer, materials such as plastics, ceramics and composites can be examined for flaws; applications for the technique include

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MATERIALS & DESIGN Vol. Vl No. 4 AUGUST/SEPTEMBER 1985