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Viewing 12751 to 12780 of 13192
1928-01-01
Technical Paper
280066
GERARD F. VULTEE
THE monocoque type of fuselage construction seems to promise satisfaction of the three requisites of prime importance; namely, high strength-weight ratio, “streamlined” form, and unobstructed interior, according to the author. The conventional method of building a fuselage consists, first, in the construction of a “form” of the required shape, upon which a layer of veneer is fastened. Other layers are applied, and thus a fuselage shell of two or three plies is completed. But the process is expensive and laborious, involving the handling and individual fitting of many small pieces. In the process described by the author, a wooden form of the exact shape of one half of the fuselage body, divided on a vertical plane passing through the center line, is built. This form, or pattern, is next suspended in a large box in which reinforcing bars previously have been woven, and concrete is poured in.
1927-01-01
Technical Paper
270049
R. E. CARLSON, W. S. HADAWAY
LABORATORY and road tests of headlighting on dry and wet road-surfaces, with various types of head-lamp beam, are described and the effects obtained are shown pictorially and data are given statistically. The test equipment and the conditions of the tests are described. Strength of the beam was controlled and the photographs were made under standard conditions so that results would be comparable. Results obtained show that depressing the beam of a depressible-beam head-lamp when an asphalt or concrete road surface is wet greatly increases the apparent intensity of the beam above the road, evidently due to reflection from the road surface, and that this intensity extends far above the horizontal height of the head-lamp, thereby defeating the object of depressing the beam.
1927-01-01
Technical Paper
270046
W. S. JAMES
1927-01-01
Technical Paper
270042
M. J. ZUCROW, H. A. HUEBOTTER
C. W. SPICER, in a paper entitled Torsional Strength of Multiple-Splined Shafts,3 which was presented at the 1927 Semi-Annual Meeting, gave results of a number of tests which supplemented an earlier series of tests, conducted by him, directed toward the same object and previously reported.4 The results of these practical tests of actual splined shafts all indicate that, while the elastic-limit of the multiple-splined shaft is considerably less than that of a plain round shaft of diameter equal to the diameter of the splined shaft measured at the base of the splines, the ultimate-strength of the splined shaft exceeds greatly that of a plain round shaft of diameter equal to the base diameter of the splined shaft.
1927-01-01
Technical Paper
270053
E. P. BLANCHARD
WE are in a new era of production that has been made possible by the broader vision of the production engineer, who is now an established factor in industry because of the demand for reduced production costs. The two factors over which he has control are labor and machinery. Labor cost is of diminishing significance as machinery takes over an increasing proportion of the responsibility for performance. To the two production principles of the division of labor and the transfer of skill to machinery is added a third principle deduced from facts observed in modern production practice. This principle is integrated production, the combining of work units, which are the smallest possible divisions into which operations are broken down by the time-study man, so that a number of identical or similar operations are performed simultaneously by multiple tools, with the maximum efficiency and economy for each tool or each work unit.
1927-01-01
Technical Paper
270011
George L. Clark, Robert H. Aborn, Elmer W. Brugmann
ABSTRACT
1927-01-01
Technical Paper
270013
Alan R. Fenn
ECONOMIC and other conditions that favored and practically forced the development of the light car in England, and the history of that development, are dealt with at length by the author. He recalls the light cars of the pioneer days of the automobile and then the putting on of weight about 1898 to increase reliability and riding comfort. He comments on the reaction that resulted in the advent of the cyclecar in 1911 and its quick demise because of its failure to perform satisfactorily. The keen interest of the public, however, indicated that a big business could be done in a light, efficient, cheap motor-car if it could be produced in a practical form. Genuinely light cars minus the crudities of the cyclecar began making their appearance and quickly “caught on,” due to the tax on gasoline, low selling prices, and automobile-club competitions giving the public confidence in these vehicles.
1927-01-01
Technical Paper
270022
JOHANNES PLUM
REMARKING the difficulty of explaining logically the strange phenomenon known as the “pivoting” of a car, the author, after presenting citations of actual experiences with various combinations of front-wheel and rear-wheel braking and their tendencies to cause a car to pivot, analyzes pivoting and explains its causes under (a) “dry-roadway” and (b) “skiddy-roadway” conditions. Concerning (a), the author states that when two-thirds of the braking force of a four-wheel-brake system is distributed to the rear wheels, the preponderance of the stopping or braking force will remain active to the rear of the center of gravity of the car, causing a so-called “drag-anchor” effect to counterbalance what is termed the “spin effect,” and no dry-roadway pivot can occur. Since the friction available between the roadway and the tires is comparatively small on a skiddy roadway, the retarding forces at the two sets of wheels should be utilized to their utmost.
1927-01-01
Technical Paper
270024
E. J. Lowry
CAST iron is purchased on a basis of price instead of quality, according to the author, who says that this has depreciated the qualities of the material generally and caused engineers to look askance at its application. Combined with such factors is the influence of misinformation about cast iron that has been widely broadcast. Questions regarding the design of patterns and cheaper raw-materials have involved the foundrymen in controversial discussion concerning the influence of various elements to the detriment of the economic condition of the iron industry as well as that of the consumer of castings. Due to the lessening of the consumption of cast iron, the foundry world has inaugurated research to better the quality of cast iron, not only through investigations of raw materials but also by improvement in melting practice.
1927-01-01
Technical Paper
270032
H. A. HUEBOTTER
ENGINE power is an expression that has a wide range of meaning. In its most fundamental sense, it is the capacity for doing work developed in the engine cylinders and is limited by the breathing capacity of the engine, that is, its rate of air consumption. The author describes a positive rotary-displacement measuring apparatus designed to overcome the objections often raised to the use of the customary type of air-meter in the induction system. The contribution describes a method for attaining greater accuracy or simplicity of operation evolved in the course of an investigation, and the method described is easily applicable by others who may have similar problems requiring solution.
1927-01-01
Technical Paper
270027
C. C. CHAMPION
NAVAL aviation confined its activities to training and to coastal patrol during the World War. This limited operation was necessitated by the small amount of materiel suitable for operation over water, the strategical and geographical situation which determined the nature of the naval operations, the very limited performance of seaplanes of that period, and the fact that warships were not equipped for handling aircraft or prepared for aircraft cooperation. At the end of the War, naval aviation was made part and parcel of the fleet. Fighting airplanes are required to gain and maintain control of the air. Observation airplanes are used for short-range scouting and also for controlling long-range fire of capital ships by reporting the fall of shot to the ship by radio. For torpedo and bombing work, the first requirement is large weight-carrying capacity.
1927-01-01
Technical Paper
270029
JOHN O. EISINGER
REPORTING on the progress of the Cooperative Fuel Research, the author considers first the general subject of engine acceleration and then describes the test equipment and procedure of the present investigation. Discussing the degree of accuracy essential and before presenting the results obtained, he calls attention to the determination of a change in engine-torque of the order of 1 lb-ft. if a tachometer or a chronograph is used to determine acceleration. The smallest change in engine-speed that could be detected by the equipment used in this investigation was 2½ r.p.m. per sec., which is equivalent to a torque of about 2 lb-ft. The calculation of theoretical acceleration is explained. A description of the first series of engine tests, consisting of a comparison of the maximum acceleration obtained with three different carbureters used without accelerating wells, is included.
1927-01-01
Technical Paper
270028
E. N. FALES, L. V. KERBER
DISCOVERY of a satisfactory method of increasing the maximum lift of an airplane wing that should have structural simplicity, high wing-loading, low landing-speed and reasonably low drag, was the object of experiments and wind-tunnel tests made by the engineering division of the War Department Air Service at McCook Field. Previous study of the “burbling” characteristics, or discontinuity of air-flow, of airfoils at McCook Field indicated that the attainment of high lift depends upon an extension of the burble angle, that the angle at which burbling occurs can be controlled, within a range of about 5 deg., by changes in velocity or in turbulence of the wind, and that if burbling can be deferred artificially still further than the 5-deg. range the lift will increase in the same proportion. Studies abroad with rotating cylinders and the magnus effect confirmed the boundary-layer theory and principles enunciated by Dr.
1927-01-01
Technical Paper
270041
C. W. SPICER
BECAUSE of interest which has developed in a previous paper by the author on the same subject, and on account of questions raised as to the nature of the deformation of splined shafts when the deformation is carried beyond the elastic-limit, the previous tests which were carried only a little beyond the elastic-limit of the specimens have been repeated and extended to the rupture point. Additional specimens typical of those commonly used for permanent fittings were also tested for their own characteristics and for comparison with the form of test-specimens that were used in the series of tests that were previously described. As in the previous tests, the results show that the torsional strength of the multiple-splined shaft is considerably less than that of a plain round shaft of diameter equal to the base diameter of the splined shaft.
1927-01-01
Technical Paper
270036
C. L. CUMMINS
1927-01-01
Technical Paper
270006
EDGAR GRAHAM
TENDENCY to detonate is probably the most important factor in determining the usefulness of fuels for internal-combustion engines. Although it is possible, by various means, to measure more or less accurately the relative knocking-characteristics of fuels, no way has heretofore been found of rating fuels that does not depend upon some arbitrary non-reproducible conditions and measurements. The general methods adopted have consisted in comparing one fuel with another, but no absolute standard has been available. Knocking is a function of several variables, the knocking characteristics of which have been found by keeping a certain number of them constant while certain others are varied, thus rating them in terms of load, the spark-advance necessary to produce knocking, the position of the throttle at which knocking begins, and the like.
1927-01-01
Technical Paper
270065
J. A. ROCHÉ
1927-01-01
Technical Paper
270063
F. G. SHOEMAKER
THE fundamental electrical and mechanical requirements of ignition equipment for aircraft engines are outlined and the special requirements peculiar to this service and that apply, in general, equally to military and commercial aircraft, are described. Brief descriptions are given of various new types of both magneto and battery ignition and the developments in each are pointed out. Characteristics of an ideal ignition system are enumerated as a basis for further development. Among the general requirements reliability is given place of first importance, followed by light weight, compactness, low cost and adaptability of a single model to engines of different types. The chief design-requirements are speed, ruggedness, simple mounting, light rotating-parts, resistance to vibration, ample lubrication, protection against moisture, and fire-proof ventilation. Each of these subjects is dealt with specifically.
1927-01-01
Technical Paper
270060
M. N. NICKOWITZ
MORE than 13,000,000 yd. of rubber-coated top-material was produced in this Country in 1926, and, in addition, approximately 6,000,000 yd. of other types of material, including pyroxylin and oil-coated fabrics, was used for automobile tops. Principal ingredients entering into the manufacture of rubber-coated top and deck material are base fabrics, crude and reclaimed rubber, naphtha, sulphur, accelerators, antioxidants, inert fillers, softeners, and varnishes. Methods of manufacture are much like those used in the production of cellulose-nitrate or pyroxylin-coated fabrics, and the types of fabric used and their preparation are similar. Processes of preparing the rubber compound, applying it to the fabric, varnishing the surface and embossing the material are described briefly.
1927-01-01
Technical Paper
270073
EDWARD P. WARNER
1927-01-01
Technical Paper
270072
LAWRENCE B. RICHARDSON
Abstract MORE and more is being demanded of Navy airplanes beyond the requirements of commercial planes. Catapulting and deck landings are required of some planes and corrosion must be guarded against. Bombers and fighting planes each have their special requirements, and planes must be able to land safely on either land or water. The most important developments in aerodynamics now going on are to restrict the travel of the center of pressure of the wings as the angle of attack changes; but widespread adoption of slotted wings and other results of experimental development may be expected. Metal is being used more than formerly in structural work but there are as yet no all-metal service-types in the Navy. Chrome-molybdenum steel is replacing mild carbon-steel in the tubular frames of fuselages, and there is a tendency to seek substitutes for welded joints. Duralumin is slowly replacing steel where welding is not required, but its adoption is retarded because of corrosion.
1927-01-01
Technical Paper
270071
C. M. KEYS
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