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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
270045
C. M. MANLY, B. LIEBOWITZ
THIS article reports research directed toward laboratory verification of deductions arrived at in Dr. Liebowitz's theoretical research.3 C. M. Manly, C. B. Veal4 and Dr. Liebowitz have been studying for some time the problem of devising an apparatus to test accelerometers. Mr. Manly and Dr. Liebowitz here summarize the results of the development work. The testing apparatus constructed incorporates an attempt to avoid the uncertain errors of any crank-motion by obtaining harmonic motion through the rotation of eccentric weights mounted on a spring-board, thus obtaining the advantage of extreme simplicity, minimum cost and at the same time avoiding the errors incident to lost motion by employing a molecular hinge. Results of a short series of experimental runs with a micrometer type of accelerometer are given.
1927-01-01
Technical Paper
270009
S. A. MCKEE
A STUDY of the performance characteristics of journal bearings when an abrasive is in the lubricant was undertaken to obtain an indication as to what effect an increase in the viscosity of the lubricant might have on the performance of the bearings of automobile engines when diluted or low-viscosity crankcase-oil is contaminated with road dust or other solid matter. The general scheme of conducting the tests involves acceptance of the common theory of lubrication of complete journal-bearings and actual operation of bearings under conditions simulating practical applications, with oils of different viscosities and with and without the addition of an abrasive. During one series of runs, an attempt was made to measure the wear that occurred. The wear on the shaft was practically negligible, but the wear on the bearings was found to have been sufficient to change the average clearance-diameter value from 1/663 at the commencement of the test to 1/597 after the test was completed.
1927-01-01
Technical Paper
270010
A. C. FIELDNER
NO danger exists of the imminent exhaustion of the petroleum reserves of the United States, as is shown by a committee report published early in 1926 by the American Petroleum Institute, from which figures are given in the following paper. It is reasonable to assume that a sufficient supply of oil will be available for all purposes beyond the time when the demand therefor will be reduced by more efficient use of petroleum products or by the production of substitutes for them. The possibility of a future shortage of petroleum fuel suitable for automotive engines, however, and of the production of substitutes to avoid such a contingency, is receiving considerable attention in America and Europe. The author presents a general review of the situation and the status of research in the manufacture of gasoline substitutes from coal, of which enormous quantities remain unmined in this Country.
1927-01-01
Technical Paper
270012
W. A. FREDERICK
SIMPLICITY is the keynote of the only two types of sleeve-valve engines that have stood the test of time, namely, the double-sleeve, or Knight, engine and the single-sleeve, or Burt-McCollum, engine, the latter type being the subject of this paper. After noting the vicissitudes through which the single-sleeve-valve engine has passed since its first introduction in 1911 and outlining the patent situation, the author describes the mechanical construction of the valve and the sleeve-driving mechanism, discusses the inherent advantages of the characteristic twisting-movement of sleeve-valves, points out the advantages of a detachable head for each cylinder, explains the principles underlying the determination of the size, shape and number of the ports and tabulates the average timing-practice of single-sleeve-valve engines. He states that the chief advantages of the single-sleeve-valve engine are sustained operating efficiency, good power-output, and silent operation.
1927-01-01
Technical Paper
270015
R. S. DRUMMOND
AFTER outlining the present status of the forms of drive for timing-gear trains, the author describes modifications of gear design made by the company he represents to overcome noise that involve lengthening gear-teeth for a given pitch. Various modifications in this regard were made and one having 16-pitch teeth with 12-pitch length had 10,000 miles of use in fourth speed without developing excessive wear. A further development resulting from experiments was the use of case-hardened timing-gears for motorcoach engines, such usage being thought to provide the most extreme conditions. Characteristics of so-called anti-stub gears are stated and predictions are made as to the future of timing-gear practice.
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
270011
George L. Clark, Robert H. Aborn, Elmer W. Brugmann
ABSTRACT
1927-01-01
Technical Paper
270026
J. W. SCHADE
ACTUAL production-equipment for making rubber goods by the anode process has not been installed and studied to yield accurate quantitative data, but laboratory work has been begun in Akron, Ohio, and although some of the facts learned cannot be discussed by the author at this time, enough general indications have been secured to lead to belief that widely varied and valuable applications of the process will be made. Factors that influence the commercial application of any process are enumerated and the properties of rubber that the technologist usually studies to determine its suitability for specific uses are listed. Thorough comparison of anode rubber with the milled product has not been made but confirmatory experimental evidence supports belief that the process must yield stronger and tougher material than do current methods of production. The reasons for this are explained.
1927-01-01
Technical Paper
270033
D. B. BROOKS, S. W. SPARROW
THE paper is limited to a discussion of the factors governing flow of the lubricant through the crankshaft and connecting-rod bearings. Apparatus for measuring the flow is described, and the fact that it permits measurement under operating conditions is emphasized. Results obtained by increasing main and connecting-rod bearing clearances are enumerated first. The paper then treats of the influence of engine-speed. Centrifugal force is shown to have a major influence on flow at high speeds, but it is pointed out that the magnitude of this influence can be controlled to a considerable extent by the radial location of the oil-hole in the crankpin. The fact that the effect of changes in pressure differs with differences in engine-speed and oil-flow is commented upon, and a possible explanation for this condition is advanced. Some results which at first appeared surprising were obtained in static tests in which the flow was measured at various crank-angles.
1927-01-01
Technical Paper
270055
H. L. Miner
1927-01-01
Technical Paper
270048
J. E. HALE
THE author compares tread-wear of front and rear tires. Considering wear of rear tires as normal wear he analyses the abnormal wear observed on front tires and traces it to its causes, which are found to be camber, toe-in and imperfect geometrical layout of steering-arms and linkages. A theory of the scuffing action is developed. It is due partly to various rolling diameters at different parts of the tire tread and partly to the setting of the two front wheels so they tend to roll in slightly different directions. Reducing the camber angle to ¾ deg. and the toe-in to 1/16 in., reduces both these errors and results in longer tire-wear. No definite theory for camber is found. Toe-in depends on camber, counteracting the tendency of cambered wheels to diverge. A method is described for testing accuracy of rolling action by means of paper on a greased floor. Service stations must be put in a position to test and correct toe-in and camber.
1927-01-01
Technical Paper
270047
S. VON AMMON
A REPORT on the investigation of brake-lining materials by the Bureau of Standards was made by the author in 1922. The present paper gives information on work done in this field since that time. It places on record a summary and discussion of various test-methods and equipment at present employed by brake-lining manufacturers and others in the automotive industry. The difficulties connected with this work, resulting from the varying characteristics of brake-lining materials, are brought out. It is shown that some of the test methods in use do not furnish a basis for ready or fair comparison of different brake-linings. Other test procedures are so limited as to give only an incomplete picture of the characteristics of the brake-linings under conditions met in service; therefore, the test schedules generally require readjustment and amplification because a full and satisfactory knowledge of these materials can be obtained in this manner only.
1927-01-01
Technical Paper
270051
THOMAS R. AGG
AN impetus to more scientific highway-construction was given by the World War, and, while it is necessary to limit the weight and size of motor-vehicles to safeguard the existing investment in highways, these limitations are being made as liberal as conditions permit. It is necessary for highway engineers to obtain a clear understanding of the interrelation of the highway and the vehicle. The author explains briefly the effects each has on the other and discusses these in connection with the problems of road location, grades, safety of users, cross-section of concrete slabs, the design of non-rigid road-surfaces, classes of highway and their cost to the public, and the economics of highway improvement and transportation. It is believed to be possible, the author states, to show that, under certain conditions, road improvement creates wealth, either in the form of lowered transportation costs or as improved social and educational conditions, or both.
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
270059
E. H. NOLLAU
1927-01-01
Technical Paper
270023
K. L. HERRMANN
THE author enumerates and describes various inter-related movements of the front end of the car that are commonly known as automobile shimmy. A long list is given of experiments made in an attempt to correct the trouble. These did not produce consistent results but showed that caster angle acts as a considerable influence, while the influence of camber and toe-in seems to be more on tire wear than on shimmy. Lubrication of springs and conditions affecting the free motion of the steering pivots have some influence but the author sees imperfections in the tires as fundamental causes. The nature of the road is also important, particularly of concrete roads having regularly spaced depressions at joints. Some of the tire imperfections are described and blame is placed on the tire makers for being less thorough in their methods of testing and inspection than are car manufacturers.
1927-01-01
Technical Paper
270065
J. A. ROCHÉ
1927-01-01
Technical Paper
270068
EDWARD P. WARNER
INFLUENCE that the research and development work done in aeronautics by the naval and military services has had in the advancement of design and construction of airplanes and aircraft engines suitable for commercial operations is pointed out and exemplified by citing a few instances of direct adaptability of military types of airplane to commercial uses. Nearly all of this work would have been done much later or not at all if the airplane had been purely a commercial vehicle, but the constructor for purely commercial purposes and the commercial operator have had the benefit of it. Major fundamentals, such as speed, safety, reliability and economy, are the same in both types of aviation; divergencies between the requirements for the two kinds of service begin to appear in materiel, personnel, or methods of operation only at a somewhat advanced stage of evolution.
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
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
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
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
1927-01-01
Technical Paper
270070
A. H. G. FOKKER
1927-01-01
Technical Paper
270069
CHARLES N. MONTEITH
MAJOR problems that have been encountered in the operation under contract of that portion of the Transcontinental Air Mail line between Chicago and San Francisco are outlined and discussed briefly. The more serious difficulties cited are: first, the operation of a single type of airplane from points at altitudes as great as 6400 ft. as well as at sea level, together with the fact that, in the case of this particular line, the heaviest loads are carried between the points of greatest altitude; second, the proper design of cowling and manifolding for the operation of the air-cooled radial engine at the extremes of temperature that are encountered throughout the year; and, third, the need for an engine that is geared down to the propeller or an engine delivering its normal power at a lower engine-speed.
1927-01-01
Technical Paper
270061
M. R. SCHMIDT
ALL large users of petroleum lubricants are endeavoring to reduce to printed form their individual ideas of what the lubricants they want should contain and what their physical and mechanical properties should be. The lubricants manufacturer finds, however, that anarchy prevails among the requirements and that the technique of writing the specifications is distinctly amateurish. One method followed is to analyze a satisfactory lubricant and embody the results in the specifications, but the specifier does not know that the product is the best for his purpose and does not possess the facilities for accurate analysis and the ability to determine the pertinent from the irrelevant factors. Another method is to select from a number of analyses and specifications items that seem important and incorporate them in the writer's specification. The result calls for a non-existent hybrid that may be impossible to produce.
1927-01-01
Technical Paper
270054
L. A. BECKER
1926-01-01
Technical Paper
260066
W. H. MURPHY, L. M. WOLFE
The equisignal method of airplane signaling consists in receiving signals, sent out by one or more transmitting stations, alternately on two loops the planes of which differ by a certain angle. If the signals obtained on the two loops are equal in intensity, the bisector of the angle between the loops will correspond to the line of sight or of wave propagation. In the development of the apparatus described in this paper, the fundamental idea made use of was that of the old Telefunken compass, which was later used to a considerable extent by the German Navy during the war as an aid to the flight of Zeppelins in their raids on England, and in which the transmitting system consisted of a number of similar directional antennae that could be thrown into the circuit in succession and had directional effects differing in orientation by 10-deg. steps.