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Precision Engineering advisory editor wins award
Precision Engineering advisory editor wins award The prestigious Annual Achievement Award from the Worshipful Company of Scientific Instrument Makers has been awarded to Precision Engineering advisory editor Dr Mike Downs for his laser length measuring interferometer and interference gas refractometer- inventions which have been patented by British Technology Group. The laser interferometer, developed at the National Physical Laboratory (NPL), for the precision measurement of length, represents an
important advance in the field of nanotechnology as it is simpler than others currently available and uses a low cost single frequency laser. The design permits large misalignments of the optical system to occur whilst allowing tracking of moving objects at very high or very low speed. The NPL laser interferometer has been designed to meet the measurement and calibration needs of industry and is a response to the inherent drive to higher dimensional precision in component manufacture
Gauging system checks valve dimensions Automatic dimensional checking of over 50 different sizes of valves produced by TRW Valves, has been made possible with a programmable, gauging machine designed and manufactured by Tesa Metrology. The flexible gauging system, accurate to 1 /~m, completes three valve stem diameter measurements in a cycle time of only 1.2 s including loading and unloading. Valves enter the inspection station on a walking beam. Each in turn is loaded onto a meauring head where three pairs of transducers, equispaced along the axis of the valve stem, close and measure stem diameter. Following measurement the valves move on for automatic
segregation. Valves outside the tolerances programmed into the computer are displaced off the production line and classified either as suitable for rework or for scrap. Those passing inspection carry on to a manual inspection station for a final visual check for surface defects, prior to packing. Full dimensional results, including calculated values for taper of the valve stem, are collected for each component. The computer then compiles mean and range data for statistical analysis and process control. Tesa Metrology Ltd, PO Box 418, Halesfield 8/13, Telford, Shropshire TF7 4QN, UK
Tesa Metrology's flexible gauging system is accurate to 1 l~n and can complete three valve stem diameter measurements in 1.2 s, including loading and unloading
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and a requirement for greater ease of assembly. It is particularly relevant for use by companies involved with machine tools and machine measurements. It is suitable for use by the semiconductor manufacturing industry and can be used by the microelectronics industry for the control of stages of manufacture. In order to achieve optimum accuracy, Dr Downs developed his gas refractometer to maintain the accuracy of length measuring interferometers and to enable high precision measurements to be made in the free atmosphere. Both interferometer and refractometer have been engineered for industrial use: they are simpler to use and cheaper than similar machines available on the market. The technology is available for licence from British Technology Group. British Technology Group, 101 Newington Causeway, London SE1 6BU, UK. National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK
CNC slantbed lathe has hydrostatic spindle and slide guideways The Slantbed-Mikroturn CNC, from Hembrug, is a fully hydrostatic CNClathe, equipped with linear slide measuring systems for an accuracy of 0.1 #m or 0.05/~m or 0.02 #m. The machine has hydrostatic bearings for the main spindle, giving an axial and radial runout of ~<0.1 /~m. The longitudinal and cross slides (also the third slide or rotary table, if mounted) have hydrostatic guideways. Hydrostatic spindle and hydrostatic slide guideways offer good running accuracy, thermal stability, freedom of wear, high stiffness independent of speed and good damping. This precision lathe has a slantbed of natural granite, covered with stainless steel protection guards. Between bed and base a system of vibration dampers are mounted. Heat and vibration generating elements, such as hydraulics, oil cooler, electrics are isolated from the actual machine and centralized in a separate service unit. Consequently favourable dynamic and static stiffness, as well as excellent thermal stability are achieved by optimal cooling of the hydraulic oil within 0.2°C
APRIL 1990 VOL 12 NO 2
important advance in the field of nanotechnology as it is simpler than others currently available and uses a low cost single frequency laser. The design permits large misalignments of the optical system to occur whilst allowing tracking of moving objects at very high or very low speed. The NPL laser interferometer has been designed to meet the measurement and calibration needs of industry and is a response to the inherent drive to higher dimensional precision in component manufacture
Gauging system checks valve dimensions Automatic dimensional checking of over 50 different sizes of valves produced by TRW Valves, has been made possible with a programmable, gauging machine designed and manufactured by Tesa Metrology. The flexible gauging system, accurate to 1 /~m, completes three valve stem diameter measurements in a cycle time of only 1.2 s including loading and unloading. Valves enter the inspection station on a walking beam. Each in turn is loaded onto a meauring head where three pairs of transducers, equispaced along the axis of the valve stem, close and measure stem diameter. Following measurement the valves move on for automatic
segregation. Valves outside the tolerances programmed into the computer are displaced off the production line and classified either as suitable for rework or for scrap. Those passing inspection carry on to a manual inspection station for a final visual check for surface defects, prior to packing. Full dimensional results, including calculated values for taper of the valve stem, are collected for each component. The computer then compiles mean and range data for statistical analysis and process control. Tesa Metrology Ltd, PO Box 418, Halesfield 8/13, Telford, Shropshire TF7 4QN, UK
Tesa Metrology's flexible gauging system is accurate to 1 l~n and can complete three valve stem diameter measurements in 1.2 s, including loading and unloading
118
and a requirement for greater ease of assembly. It is particularly relevant for use by companies involved with machine tools and machine measurements. It is suitable for use by the semiconductor manufacturing industry and can be used by the microelectronics industry for the control of stages of manufacture. In order to achieve optimum accuracy, Dr Downs developed his gas refractometer to maintain the accuracy of length measuring interferometers and to enable high precision measurements to be made in the free atmosphere. Both interferometer and refractometer have been engineered for industrial use: they are simpler to use and cheaper than similar machines available on the market. The technology is available for licence from British Technology Group. British Technology Group, 101 Newington Causeway, London SE1 6BU, UK. National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK
CNC slantbed lathe has hydrostatic spindle and slide guideways The Slantbed-Mikroturn CNC, from Hembrug, is a fully hydrostatic CNClathe, equipped with linear slide measuring systems for an accuracy of 0.1 #m or 0.05/~m or 0.02 #m. The machine has hydrostatic bearings for the main spindle, giving an axial and radial runout of ~<0.1 /~m. The longitudinal and cross slides (also the third slide or rotary table, if mounted) have hydrostatic guideways. Hydrostatic spindle and hydrostatic slide guideways offer good running accuracy, thermal stability, freedom of wear, high stiffness independent of speed and good damping. This precision lathe has a slantbed of natural granite, covered with stainless steel protection guards. Between bed and base a system of vibration dampers are mounted. Heat and vibration generating elements, such as hydraulics, oil cooler, electrics are isolated from the actual machine and centralized in a separate service unit. Consequently favourable dynamic and static stiffness, as well as excellent thermal stability are achieved by optimal cooling of the hydraulic oil within 0.2°C
APRIL 1990 VOL 12 NO 2