In 1940 there were fewer striking developments in machinery and in engineering generally than for several years past. This was undoubtedly due largely to the war, which has demanded large quantities of war materials of many kinds rather than the development of new devices. Perhaps the main development has been the utilization of machine building capacity already in existence to avoid loss of time and to avoid the building of new plants that may not be needed after the war is over.
Machinery for the making of munitions of all kinds has received careful attention, but much of it has been a revamping of the machines used in 1915 to 1918, as the work to be done has not changed materially. Better materials in the way of castings for the bodies or frames, better steels for the shafting, gears and driving members, better bearings and improved cutting materials, have all played their part in securing increased production.
Machine tools, as is always the case, are the bottleneck when greatly increased production becomes necessary. This has led to the adoption by some wide awake builders of the plan long used by the automobile builders, of having parts of their machines built in outside factories. A few have carried this to greater extremes than were believed possible, but with very good results. In most cases the complete assembly of the machine is done in the plant of the builder, who is responsible for its performance. This 'farming out' of work has been done to a much greater extent than ever before and has made for a greater utilization of the machine resources of the country.
The great demand for airplanes, guns and munitions has led to evolving methods of speeding their production. Plane builders are adopting more and more the 'farming out' method. In several sections where airplane plants are located a systematic survey of existing facilities has been made and tabulated. These facilities have been made available to all manufacturers and have helped to make increased output possible, and to spread employment without unduly disturbing housing facilities. The great accuracy required in the building of aircraft engines and similar parts has made the task difficult. But outputs have been materially increased by this method although not as yet to the desired extent. Airplane construction has, however, been stepped up considerably, particularly in the production of training planes and small planes for private use. One builder of small planes has been able to introduce line production methods and so greatly increase his output.
Air transport also has forged ahead, particularly in the matter of transoceanic flying. The Clipper ships to Europe and the Philippines are performing an invaluable service at a time when ocean travel is extremely hazardous. New routes are being tried out, particularly to link us more closely with our South American neighbors. (See also AVIATION.)
Machine tool builders have been busier than ever in their history, supplying Great Britain, and France before her collapse, as well as the great demands of our own country. Few new tools have been developed, however, except for shell work and other munitions. These are for the most part modifications of machines built for similar work for the last war, with the addition of hydraulic feeds in some cases. For hydraulic feeds and other movements are growing in use on machine tools, even on the smaller sizes. The hydraulic clutch, or 'fluid fly-wheel,' is also making its way in the automobile field. It is very simple, being merely a vaned impeller, a mating member connected to the drive shaft, both enclosed in an oil-tight case. It provides a very flexible connection between the engine and the rear wheels. It is not new, experimental work dating back at least twenty years in this country. It gives a very smooth start and is easy on tires. A recent application of hydraulics is a device to raise and lower the windows in high-priced automobiles.
One problem of demand for shell and other machinery is to keep it as simple as possible so that its operation can be taught to men and women who have never before handled machinery of any kind. This works in favor of the single purpose machine rather than the more highly developed and more universal machines that can perform many operations at a single setting. Shell work, too, has brought out the advantages of the high speed steels for removing large quantities of metal as is necessary in this work. With heavy simple machines it is easier to take heavy cuts and coarse feeds at a slower rate of speed than to use the carbide tools with high speeds and light cuts.
Another advantage of the simple machine is that it can be built in shops not familiar with, or equipped for, building machine tools of the more complicated types. This view is being held by the War Department, which has plans for extremely simple shell lathes, modified since the last war to meet present conditions. It has also a complete set of suggestions as to methods, speeds and feeds and depth of cuts. In addition it has tabulations as to the number of machines needed to turn out a given number of shells per hour of the various sizes likely to be needed, up to and including 16-inch projectiles.
The growth of furnace brazing for the joining of many metal parts has made possible the redesigning of many parts in a way that simplifies their manufacture. By this method several simple parts can be joined into one unit that would be very complicated if made in one piece.
New materials and new uses for older ones continue to appear. Stainless steel, for example, is widening its fields of usefulness in the air, in the new light-weight streamlined trains, and in marine work as well. Blades for steam turbines take more of this comparatively high-priced metal than many realize. In navy and coast patrol planes, stainless steel is used extensively in ribs, spars and for the covering of the fuselage. One of its advantages is that it can be joined by shot welding without materially reducing its strength. This gives it a marked advantage over duralumin, which must be carefully riveted with heat treated rivets.
Experiments with formed plastic sheets for aircraft continue to attract attention but have not yet gone into real production. They seem to offer possibilities for more rapid production of the plane fuselage and wings than any other method. The success of this method would be a great forward step in many ways.
New applications of the control of machines by light waves, known as the 'electric eye,' continue to be made. In one recent machine the light beam is used to detect, and reject, paper stock that does not come up to specifications. In this modern machine for making envelopes, a defective envelope blank, one that has a thin spot or other flaw, permits enough light to pass through to stop the machine. In other machines the light beam is used to operate relays which control hydraulic valves that, in turn, control powerful mechanisms.
Until the war is over and we again turn our attention to peacetime pursuits, engineering energy must be directed toward the making of implements of destruction. Development of devices to improve normal living must of necessity remain in the background.
No comments:
Post a Comment