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Viewing 15901 to 15930 of 16003
1931-01-01
Technical Paper
310008
Edward M. Getzoff
MORE THAN SEVEN YEARS of investigation of the problem of preventing valve-seat erosion under severe operating conditions in motor-truck and motorcoach engines are reviewed briefly. Engineers are said now to be generally agreed that an insert of some non-ferrous material is the only means of obtaining a valve seat that will stand severe service. A theory for the cause of a thin spotty deposit or pick-up on the valve seat that accelerates erosion is advanced, and this deposit is said to be absent on valve seats made of non-ferrous metals. Aluminum bronze gives satisfactory results but is difficult to secure to cast-iron cylinder-blocks because of its greater coefficient of expansion. Several partially successful methods of securing aluminum-bronze rings to cast iron are shown. A method that is applicable to one alloy which has reduced erosion under the most severe operating condition to such an extent that it is almost negligible is described.
1930-01-01
Technical Paper
300010
FRANK JARDINE
1930-01-01
Technical Paper
300003
F. A. Moss
This is the fourth report by Dr. Moss on the investigation of riding comfort at the George Washington University and is a progress report on the measurement of automobile riding-qualities. The previous reports were published in the S.A.E. JOURNAL as follows: September, 1929, p. 298; January, 1930, p. 99; and April, 1930, p. 513. In this report, which was presented at the 1930 Semi-Annual Meeting, the author describes improvements made in two wabblemeters for measuring physiological fatigue caused by riding and the use of two accelerometers to correlate the behavior of the automobile with the physiological results. Results obtained with two groups of subjects, one consisting of taxicab drivers and the other of university students, are summarized, and the results of preliminary tests of the comparative riding-qualities of different cars as shown by their effects on the subjects are also given.
1930-01-01
Technical Paper
300002
F. A. Moss
EXPERIMENTS that have been in progress since the 1929 Semi-Annual Meeting to measure the fatigue caused by an automobile ride, using the human body as a measuring instrument, and to predict there-from the possible effects of various types of spring-suspension, shock-absorber and other comfort-giving components are described. Initially, the problem was approached from the physiological standpoint because fatigue is definitely known to be a physiological phenomenon and, if the physiological changes are sufficiently marked to be measured, physiological tests are definite and quantitative. Changes in the human body are a good index of relative comfort, and, if the normal reactions of an individual or any group of individuals before a test are known, similar measurements at the end of a test or at the end of an automobile ride should show an appreciable difference.
1930-01-01
Technical Paper
300040
R. L. Templin
COMPARATIVELY large rake and clear angles required for best results leave a relatively thin cutting-edge on a cutting tool for aluminum. One difficulty encountered is that tools of such form are not always available or suitable, for various reasons, for instance, small tools of various types are available only with cutting edges suitable for steel and bronze, and the desirable amount of top rake cannot well be provided on circular form-tools. Tool bits of various sorts can be reground to the desired angle. A simple round form of tip that is shown can be utilized in tools for various purposes, including use as inserted teeth in a face-milling cutter. High-speed-steel tools are suitable for most aluminum alloys, but alloys containing a high percentage of silicon can be machined to advantage only by using cemented tungsten-carbide. Machine-tools should be suitable for high speed.
1930-01-01
Technical Paper
300024
S. D. Heron
FUELS for use in aircraft engines are discussed with reference to their antiknock value, volatility, vapor-locking and engine-starting properties, gum content and availability, and to antiknock agents. The usefulness of a fuel for spark-ignition engines is stated to be limited by its tendency to heat the cylinder and the piston unit. Definite evidence is available that the tendency of fuels to heat the cylinder unit is not always in accord with their tendency to cause audible knocking. The fuel required depends upon the compression ratio of the engine, its volumetric efficiency, the design, size and temperature of the cylinder unit, and the rate of revolution. Mid-Continent Domestic Aviation gasoline having an approximate antiknock value of 50 octane-50 heptane gives excellent results if the engine output is kept within the limitations of this fuel but is not suitable for many modern aircraft engines if flown wide open at sea level.
1929-01-01
Technical Paper
290045
R. H. SOULIS
FIRST reviewing briefly the history of molded brake-lining, the author states that the introduction of molded lining has, until recently, met with considerable opposition. After the first volume-production adoption in 1924, there were no further adoptions of the strictly molded types in production until 1927, when the trend in brake design seemed to change suddenly from the external type to the internal type of brake. The present movement toward the use of molded brake-lining was brought about through the inability of woven lining to meet the exacting demands of some of the newer types of internal brake. In the author's opinion, the molded type of lining has more nearly fulfilled the present requirement of internal brakes than has any other type. He states that at least seven different brands of molded lining are now on the market, and that three of them are in large-volume production.
1929-01-01
Technical Paper
290043
A. B. Cox
1929-01-01
Technical Paper
290003
FRED AUGUST MOSS
THIS IS a preliminary report of the results obtained to date in the study of fatigue incident to motor travel, which is part of the Society's Riding-Qualities Research program. A series of physiological tests were conducted after muscular fatigue had been induced by a known amount of work, with the hope of finding some tests sufficiently sensitive to measure less pronounced types of fatigue. These fatigue tests conducted on subjects after riding showed that a decrease in the carbon-dioxide combining power of the blood and an increase in metabolism are fairly satisfactory indications of muscular fatigue, but the results led to the conclusion that the fatigue which accompanies riding in automobiles does not represent a very marked muscular fatigue, and suggested that it may represent a condition more closely similar to nerve fatigue. Consequently, a rather extensive study of various tests of nerve fatigue was undertaken.
1929-01-01
Technical Paper
290064
E. H. DIX
ALUMINUM and magnesium, being the lightest commercial metals and therefore the most suitable for aircraft construction, are discussed in their pure and alloyed states. Physical properties of the pure metals and their alloys are given and the effects of adding small quantities of alloying elements are shown. Heat-treating as a means of increasing the strength per unit weight of the alloys is discussed at length, together with the effects of natural aging and artificial aging at elevated temperatures and of quenching in hot and in cold water after heat-treating. The several types of corrosion are considered and resistance to corrosion of the metals and their various alloys are discussed. Protection afforded to aluminum alloy by a surface coating of pure aluminum is described, and other methods are mentioned.
1929-01-01
Technical Paper
290071
ZAY JEFFRIES
1929-01-01
Technical Paper
290063
G. D. WELTY
A NUMBER of the more important commercial alloys having aluminum as their base are discussed by the author, who points out their main physical characteristics and outlines methods which can be used in their fabrication, indicating in a general way which alloys are best suited to various aircraft-engine requirements. Tables are given showing chemical compositions and physical properties, including a table of physical properties of various casting alloys at elevated temperatures. Special-purpose alloys are commented upon, and also a new aluminum alloy for pistons which is beginning to find commercial application and possesses properties particularly desirable in aircraft engines. Recent developments in magnesium alloys and their application to aircraft-engine design are specified, tables of physical properties are given, and comments are made on the characteristics of the material as compared with aluminum alloys.
1929-01-01
Technical Paper
290066
L. B. RICHARDSON
AT first believed immune, aluminum alloys have been found extremely susceptible to both surface corrosion and intercrystalline corrosion. The latter goes on under paint that has been applied to imperfectly cleaned surfaces, and shows only as blisters. Because of this, it has become commonplace to break with the fingers the ribs and the trailing edges of duralumin lower wings and tail-surfaces. Contact of duralumin with brass or steel hastens corrosion, and protective paint coverings are dissolved by dope where fabric surfaces meet metal parts. All-duralumin structures are not considered suitable for sea-going aircraft unless all joints and seams are of water-tight construction, not only in hulls but in other members of the structure. Corrosion over the land is much less severe. Few manufacturers seem awake to the importance of corrosion. The fight to avoid it should begin with avoiding seams that are difficult to protect and hollow members that cannot be sealed hermetically.
1929-01-01
Technical Paper
290040
E. R. LEDERER, F. R. STALEY
SELECTION of the proper crude is an important consideration in the manufacture of aviation-engine oils. The authors class petroleum into asphalt-base, paraffin-base and mixed-base crudes, stating that scientific research and actual-performance tests have demonstrated the advantages of paraffin-base oils over asphalt-base oils for aviation engines, and that their superiority is now conceded by most authorities. Much attention has been given recently to the dewaxing and fractionating of lubricating oils, and this has resulted in an improvement in their quality and in their unrestricted use as “all-weather aero oils.” After quoting statements from several authorities who agree that an oil which will meet both summer and winter requirements is desirable, the authors give the definitions of viscosity, fluidity, consistency and plasticity determined by the American Society for Testing Materials and then discuss the fluidity or consistency of aviation-engine oils below their A. S. T.
1928-01-01
Technical Paper
280058
BIRGER EGEBERG
AFTER outlining the progress of research in the development of the alloy steels, the author says that alloys of steel containing nickel, chromium, and nickel and chromium, are the most important to the automotive industry, which is especially interested in alloys containing up to 5.0 per cent of nickel and up to approximately 1.5 per cent of chromium, with the carbon content ranging from 0.10 to 0.50 per cent. The additions of these amounts do not materially change the nature of the metallographic constituents, but the elements exert their influence on the physical properties largely by altering the rate of the structural changes. In straight carbon-steel, especially of large sections, it is not possible by quenching to retard the austenite transformation sufficiently to produce as good physical properties as are desired.
1928-01-01
Technical Paper
280025
C. D. HOLLEY
THE finishing of automotive products with lacquer is still in the transition stage, according to the author. Sufficient time has not elapsed to provide an adequate background of experience which establishes principles and practices that fully meet the requirements of the production engineer. In other words, many of the things we think we know about lacquer finishes and lacquer undercoatings are either not true or are correct in part only. The general function of a surfacer is to provide a smooth surface for the finishing coats. Inasmuch as the larger part of the material applied to provide such a surface must be cut away by sanding so as to bring the surface as a whole to the requisite smoothness, a satisfactory surfacer is one that can be applied with the minimum effort, can be sanded with the minimum amount of labor, and can be purchased cheaply, the reason being that most of it is carried away by the wash water during the sanding process.
1928-01-01
Technical Paper
280022
THOMAS H. WICKENDEN
THE hardness or chemical composition of an iron is, by itself, no indication of the wearing property and machinability of the iron. Irons containing a large amount of free ferrite have been found to wear rapidly, whereas others having considerable pearlite or sorbite in their structure show good wearing properties. The presence in cylinder-blocks of excess-carbide spots or of phosphides of high phosphorus-content is deleterious, because such spots wear in relief and the material ultimately breaks out, acting as an abrasive that scores the surfaces. Causes of wear in cylinder-blocks are discussed, and nickel, or nickel and chromium, intelligently added to the iron is suggested as a means of obtaining the correct microstructure for a combination of good wearing properties and machinability.
1928-01-01
Technical Paper
280024
EDWIN M. BAKER, WALTER L. PINNER
1928-01-01
Technical Paper
280023
E. J. JANITZKY
AN outline is given of the work performed and the method of procedure followed in correlating test results on specimens of heat-treated S.A.E. chromium-vanadium steel 6130 as a basis for revision of the physical-property charts for certain automotive steels. Revision of the charts was proposed by the Iron and Steel Division of the Standards Committee of the Society, and a subcommittee, of which the author is a member, was appointed to carry on the preliminary work of revision. The paper is a report of the results of the tests made. Test specimens of S.A.E. Steel 6130, to be drawn at three different temperatures after quenching, were prepared by four steel manufacturers. These were distributed among 30 cooperating laboratories, which made a series of about 115 tests including complete chemical analysis, tensile-strength, and Brinell, scleroscope and Rockwell hardness tests on the specimens.
1928-01-01
Technical Paper
280016
H. A. HUEBOTTER
COMPROMISES are necessary in designing a piston, sacrificing the quality of least importance under the given conditions. Aluminum alloy is seen as a most desirable material because of its high conductivity and low rate of absorbing heat from hot gases. Aluminum-alloy pistons are now made for oil engines with bores up to 18 in., as well as for small gasoline engines, those described in this paper having their expansion controlled by steel bands embedded in the aluminum but not bonded thereto. Slots cast in the piston allow for linear expansion of the alloy without a corresponding increase in piston diameter and change in cylinder clearance. Advantages of strut-type pistons are shown by thermal diagrams. Illustrations show large pistons and engines in which they are used. Cores and steel inserts for producing such pistons are shown also.
1928-01-01
Technical Paper
280059
R. S. ARCHER
THE rapid progress of the present age in technical matters is highly gratifying, the author says, but most of us find it something of a problem to keep up with this progress. The automotive industry draws from many highly specialized arts and sciences and there are perhaps few individuals who have time to keep up with the details of progress in all these fields. The last decade has been one of intensive research and development in the aluminum industry. The close relation between this industry and the automotive industry is indicated by the fact that the automotive industry has at times consumed as much as half of the entire aluminum production. It is natural, therefore, that much of the work on aluminum has been done to provide improved products for the automotive industry and some of them are described.
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
270025
S. E. SHEPPARD
AFTER giving a brief description of the nature of rubber latex and a review of investigations made in Europe of its physico-chemical properties, the author tells of experiments made in Rochester to develop a method for the electrodeposition of rubber particles. These proved that the process was possible but the problem of producing a coating containing all the ingredients requisite in a compound suitable for vulcanizing remained to be solved. The nature of the rubber particles and of rubber after coagulation of the particles is described and the method of rubber-plating as developed is explained. It is stated that the deposit can be built up almost indefinitely and at a very rapid rate; that the composition remains substantially unchanged during coating, and that the current efficiency is remarkably high.
1927-01-01
Technical Paper
270014
E. F. BEHNING
ACCORDING to the author, gear clatter and clash caused by metal-to-metal contact develops into an annoying whir or howl at high gear-speeds, and a material was sought that is flexible and resilient enough to absorb the vibrations or change their frequency to a pitch inaudible to the average human ear. Since vibrations in the crank, the cam and the generator shafts are transmitted to the timing-gears, which run at high speeds, a material was needed that would silence the consequent noise and provide a noiseless timing-gear train. A great variety of materials was investigated and the development of laminated, phenolic, condensation products resulted; these have proved mainly suitable for timing-gear-blank stock and stock for other gears such as those suitable for crankshafts and generator shafts. A further development was that of the flexible-web cam-gear made of the composition material.
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
270058
W. A. Gibbons
1927-01-01
Technical Paper
270066
R. D. WEYERBACHER
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
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
270059
E. H. NOLLAU
Viewing 15901 to 15930 of 16003