FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1952
1952 - 0998.PDF
454 FLIGHT, n April 1952 THE INDUSTRY A New Nimonic FROM the outset of gas-turbine manufacture in this country, the nickel-chromium alloys developed under the name of Nimonic by the Mond Nickel Co., Ltd., have been the standard materials for the manufacture of the turbine rotor blades of every British aircraft gas-turbine in production. To maintain this remarkable record, the company now announces the development of Nimonic 95—an alloy generally similar to Nimonic 90, but with a higher percentage of hardening elements. The new material can still be hot-worked and machined, and, while exhibiting mechanical properties similar to those of Nimonic 90, can be employed at a temperature some 50 deg C higher. This means that Nimonic 95, at 800 deg C and under a stress of 19 tons/sq in, will take 50 hr to reach tertiary creep and 75 ht to rupture, with a creep-rate in the secondary stage of less than 0.01; the same figures will apply under a stress of 12 tons/sq in at about 920 deg C. Dollar Earners THAT the products of Desoutter Bros, Ltd.—electric and pneumatic power tools—are, in the export field, one of the most efficient converters of steel into foreign currencies is re marked by their chairman, Mr. E. R. Desoutter, in the annual report circulated to shareholders: he points out that this conver sion-rate represents over £6,000 per ton of steel. The report states that the sales volume for the year under review increased by 17 per cent over that for the previous year, and that a very large proportion of the total output is being exported to more than fifty countries. Low-frequency Generating Plant THE aircraft industry is finding numerous applications for a variable low-frequency generator supplying constant voltage. Recently, Electro Plant, Ltd., of Wembley, Middlesex, were asked by a leading aircraft manufacturer to design such a generator for supplying a 2 kW vibrator with a frequency varying between o and 50 c.p.s. A normal d.c. machine is used, the windings being converted to triplex form to give the required voltage of approximately 110. Power is supplied by a single-phase, squirrel-cage motor, which also drives a generator supplying a busbar voltage of 200. This latter voltage, after regulation, supplies the field current for the main d.c. generator, a secondary d.c. machine, and a d.c. motor. This second motor is supplied with armature current from the secondary d.c. generator and is employed to drive the brush-gear of the main output generator at any speed between o and 1,500 r.p.m., the speed being controlled by the potentiometer regulating the secondary generator field current. This rotation of the main brush-gear was expected to lead to trouble caused by variable centrifugal brush-loading; in the present apparatus, the brushes are held against the commutator by balance weights which have been found perfectly effective in practice. The prototype rig, which we examined recently, works satis factorily, giving very constant voltage throughout the range of frequencies. Northern Aluminium Appointments TT is announced that Mr. Fraser W. Bruce has been appointed -*• managing director of the Northern Aluminium Co., Ltd., in succession to Mr. Kenneth Hall, who has accepted an appoint ment in the head office of the Aluminium, Ltd., group of com panies in Montreal. Mr. Bruce, a Canadian who was well known in the British aluminium industry before the war, has for several years been vice-president and general sales manager of the Aluminum Com pany of Canada, Ltd., which he joined on graduating from the University of Toronto in 1927. He was in charge of the London office of Aluminium Union, Ltd., from 1936 to 1939. Mr. Hall has been managing director of Northern Aluminium for the past five years. Under his direction, the construction and installation of the large continuous strip mill at Rogerstone, South Wales, was successfully undertaken and completed. He has been prominent in the light metals industry in Great Britain, having served as president of the Aluminium Development Association and as chairman of the Aluminium Industry Council. Northern Aluminium also announce new appointments in their sales department. Mr. J. H. Mayes, manager of the develop ment division since 1946, becomes castings and forgings sales manager, with an office at the Birmingham works; he is succeeded by Mr. H. M. Louch, from the London sales office. Hitherto part of the development division, publicity now becomes a separate division under Mr. E. D. Iliff, who has been publicity manager for the last seven of his seventeen years with the company. Lightweight Tachometer Generator SIMILAR in principle to, and mechanically interchangeable with, the standard Mk VIII generator, a new lightweight engine-speed generator is being marketed by Smiths Aircraft Instruments, Ltd. A circular-magnet rotor is used, mechanically locked to the drive shaft. Tappings are taken from the three-phase windings of the slotted stator and crimped to a four-pin ceramic plug-cohnector which has been speci ally designed for the generator and is both leak- and fire-proof. The compact lightweight tachometer generator. *** ' - -•%, Drive is effected by a standard S.B.A.C. splined shaft and quill-drive and attachment is made by a mounting flange bolted directly to the engine. The generator is designed to operate effectively when immersed in oil; no oil seal is there fore fitted and the maximum operating ambient temperature has been placed at 125 deg C; this is 25 deg C higher than is per missible with the Mk VIII generator. Only one engine-speed indicator can be driven from this gener ator, due to electrical limitations imposed by the small overall dimensions. The unit is not, therefore, intended to be a substitute for the company's heavier generators. Essex Aero and the M.A.C. FOLLOWING the recent announcement of the setting-up of a body to be known as the Magnesium Advisory Committee the following statement has been made by Essex Aero, Ltd., Gravesend:— "Essex Aero, Ltd., wish to make it quite clear that they were not in any way concerned in the recent formation of a Magnesium Advisory Committee stated to have been set up by the principal companies of the magnesium industry. As Ministry of Supply returns show, this company was responsible during the period January 1st, 1950, to December 31st, 1951, for an output of 1,439 tons of rolled sheet and strip magnesium of the total U.K. output of 1,487 tons, some of which has been exported to the U.S.A., added to which there is a large output of cast products from the company's foundry. The company therefore considers itself a major producer. "Essex Aero, Ltd., were asked to participate in this enterprise, but felt bound in the interest of the industry as a whole to pre serve their complete independence. In the use of the words 'the principal companies of the U.K. magnesium industry have formed a consultative and advisory committee to be known as the Mag nesium Advisory Committee,' the statement is not strictly accurate. Similar remarks apply to the words 'It will also serve as the official liaison body for negotiations with Government departments on all matters concerning the industry.' "As producers of approximately 97 per cent of the U.K. total output of rolled and strip magnesium, Essex Aero, Ltd., are bound to point this out." Since the above statement was made, the following comment has been issued by the Magnesium Advisory Committee over the signature of the chairman, Mr. E. Player:— "The formation of this representative committee has been wel comed by the Ministry of Supply as affording a useful means of consultation between the industry and the Ministry on matters of mutual interest in the magnesium field. It is not concerned with sale prices and in no sense affects the independence of individual members. "Essex Aero, Ltd., refused an invitation to co-operate, as they were fully entitled to do. Their abstention is regretted and the invitation to join the new committee remains open to them at any time they care to accept it."
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
