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Viewing 33091 to 33120 of 33174
1929-01-01
Technical Paper
290007
AUSTIN M. WOLF
1929-01-01
Technical Paper
290021
RICHARD E. BISSELL, GORDON T. WILLIAMS
DESIGN and the material used in the construction of automotive poppet valves, particularly exhaus valves, are discussed in connection with the necessity of resistance of the valves to physical and chemical actions of wide variety. The problem of resisting these actions lends itself to mechanical and metallurgical solution. Each part of the valve-the head, the stem, and the end and tip of the stem-is discussed separately; and the design of the head is considered as it relates to the upper or combustion-chamber surface, the edge, the seat and the lower or manifold-radius portion. Provisions made for the grinding-in of the valves are shown and described.
1928-01-01
Technical Paper
280034
R. E. PLIMPTON
TO solve fleet-operation problems successfully, a professional consciousness is needed among the supervisors and the engineers engaged in the operating field, awakened by analyzing and making known generally the methods and practices used by the operators of individual fleets of motor-vehicles, according to the author. In developing his subject he asks the following questions and comments upon them: Has the operator any influence on design? Is that influence good or not? Whatever the influence is, can it be improved and made more effective? If it can be made more effective, how can this be done? If it cannot be made more effective, what is the reason? Regardless of variations in duties and of conditions in organization, each large-scale operator is vitally concerned with matters of design and construction.
1928-01-01
Technical Paper
280048
H. A. HUEBOTTER
In this article the author presents analytical methods for determining the unbalanced inertia force and the tangential effort in a line engine. These methods are thought to be of interest for investigation of the effects of various engine design-features on its vibration characteristics. An equation for the resultant reciprocating force is set forth and methods of expressing the inertia and fluid-pressure torque are given. The determination of minimum and maximum resultants and the balance of inertia and fluid-pressure torques are other topics dealt with. The results of a series of analyses are incorporated in tabular form.
1928-01-01
Technical Paper
280037
MAURICE PLATT
EUROPEAN trends in some of the major features of engine, chassis and body design and in several items of equipment are reviewed in this paper; which is based on the observation and analysis of the British engineer editor who is its author, and of the staff of The Motor, of London, during the last five years. Although American automotive engineers who follow European practice are acquainted with most of the designs here shown and described briefly, this paper is of interest and value as showing the present principal lines along which development is taking place abroad. Popular chassis types are divided into three classes: (a) the “baby” four-cylinder car of 7 to 9 hp., Royal Automobile Club rating; (b) the “family-type” four-cylinder car of 12 to 14-hp. rating; and (c) the light six-cylinder car of 15 to 20-hp. rating. Typical acceleration curves for well-known cars in each of these classes are given, as well as cylinder dimensions, volumetric capacity, car weight and price.
1928-01-01
Technical Paper
280065
E. E. WILSON
Abstract THREE basic ways in which naval aviation can assist the battle fleet to attain victory are stated, and the aircraft are classified as fighting, observation, torpedo and bombing, and patrol planes. The primary and secondary uses of the types are set forth, and, since their tactical employment controls the features of their design, a brief sketch is given of the tactical considerations of fleet air-work. The development of naval aircraft to date and the trend of future development are then described. As naval fighting planes must be carried on the ships of the fleet and must have the utmost possible performance and service ceiling compatible with low landing-speed, their size and weight have been reduced by the use of air-cooled radial engines and the intelligent employment of light alloys and ingenious detailed construction. The latest development in this class is a single-seater designed around the Wasp 500-hp. engine and equipped with a supercharger.
1927-01-01
Technical Paper
270052
H. D. CHURCH
The paper deals primarily with internal wheel-brakes for trucks and motorcoaches, but passenger-car brakes with similar characteristics are considered possible. A simple two-shoe internal-expanding type developed mainly by empirical methods is found to be the most practical solution in spite of relatively low circumferential contact. Self-energization is necessary to reduce driver effort with normal pedal-travel. The factors controlling self-energization are explained in detail, and the effect of difference in the coefficient of friction of brake-linings is noted. Distortion of brake-drum and brake-shoes must be limited by a drum of heavy section and by extremely rigid shoes. Rotation of cam with respect to self-energizing shoe should tend to deflect the toe of shoe away from brake-drum surface. A floating cam is necessary to balance unequal wear on the brake-shoes and assure adequate braking with normal pedal-pressure.
1927-01-01
Technical Paper
270016
F. M. HAWLEY
TOOTHED and friction-gearing are said by the author to be the two distinct classes of power transmission between two shafts, and the silent chain he describes is in the toothed-gearing class according to his statement, since it has a fixed speed-ratio and causes a bearing pressure that varies almost directly with the power transmitted. It is argued that, because of its elasticity and the peculiar method of contact with the teeth of the sprocket, the silent chain constitutes a medium that absorbs shocks and variations in angular velocity, and has a bearing action similar to that of a belt. The improved silent chain is made of stamped, arch-shaped link-plates assembled in alternate succession and joined by pins that act as bearings. The spacing of the pins forms the “pitch” of the chain. When assembled, the chain can be considered a flexible gear or rack.
1927-01-01
Technical Paper
270034
M. V. DAVIDSON
MATHEMATICAL analyses of the force required to accelerate the reciprocating parts of six and of eight-cylinder engines and of the axial and perpendicular components of the force needed to accelerate the connecting-rod are presented by the author. He then shows mathematically that the division of the connecting-rod into reciprocating and rotating elements is correct theoretically. Having obtained exact expressions for the forces required to accelerate the reciprocating parts and the connecting-rod and having shown that the usual treatment given the connecting-rod is correct theoretically, mathematical study is made of the reciprocating balance of six and of eight-cylinder engines for comparative purposes and comparison is made numerically between six and eight-cylinder engines having equal total weight of reciprocating parts. A study of the angular acceleration of the connecting-rod is also presented in the article.
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
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
270071
C. M. KEYS
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.
1926-01-01
Technical Paper
260063
ARTHUR NUTT
The marked advance that has been made in the last 10 years in constructional details and in performance of airplane engines and in airplane performance is reviewed, beginning with the year 1916 when the Curtiss OX-5 eight-cylinder water-cooled engine was brought to its final stage of development. The author describes briefly each type of engine produced successively by the company he represents and tells of the changes that were made to improve the performance. From the 8-cylinder V-type the constructors changed to the 6 and 12-cylinder water-cooled type and are now developing a 9-cylinder air-cooled radial engine that was built in 1925. An important field of usefulness is foreseen for the air-cooled engine.
1926-01-01
Technical Paper
260020
L C HUCK
A heavy high-speed vehicle, such as a modern motor-coach, combines weight and speed, requires frequent brake-applications and necessitates the dissipation of an increased quantity of heat. As it weighs about four times as much as a passenger car approximately four times the braking-effort is required; consequently four times as much pedal-pressure must be exerted. To supplement the driver's muscular equipment, some outside force, such as compressed air, the vacuum of the intake-manifold or the inertia of the moving vehicle, must be utilized. The author limits his present discussion to the use of the last-named force which he terms the use of “self-actuation,” and also to its application to the rigid-shoe type of internal wheel-brake. Through mathematical analysis he determines the effect of self-actuation measured in terms of the increase or decrease of the cam pressure required to sustain the same normal pressure before and after an outside torque has been applied to the brake drum.
1925-01-01
Technical Paper
250051
C O GUERNSEY
Various efforts have been made to apply the internal-combustion engine to self-propelled rail-cars. The greatest development along this line prior to the war was in connection with the McKeen and General Electric cars that were built from 1906 to 1914. The builders of those cars were greatly handicapped by the lack of available experience in connection with the design of gasoline engines, particularly of the larger type. Since the war a gradual development of rail-cars has taken place, starting with small converted motor trucks and gradually increasing in size and adaptability to the service, until now gasoline-electric cars of 250 hp. and about 75 ft. in length are available, while mechanically driven cars are available up to 190 continuous horsepower.
1925-01-01
Technical Paper
250027
L M WOOLSON
Advances in airplane performance during the last few years may be ascribed mainly to advances in aerodynamics and to improvements in powerplants. The latter have resulted in producing more power for the same weight of engine and smaller over-all dimensions for engines of the same power-rating. The accompanying paper describes two engines of 500 and 800 hp. respectively that have been recently developed by the Packard Motor Car Co. for aircraft service. When these engines are compared with previous types they are found to be more compact and to produce more power per pound of weight. When each is operated at its rated speed, the Model 1500 engine develops 100 hp. more than the Liberty while weighing 140 lb. less, and the Model 2500 engine develops 250 hp. more than its predecessor, the Model 2025, with a decrease in weight of 75 lb.
1925-01-01
Technical Paper
250043
H H ALLEN
Claims and counter-claims as to the deceleration possible under certain conditions, especially when applied to the legal questions arising at the time of an accident, induced the author to make an investigation of the subject. An attempt has been made to include all the variables that are of significance or of sufficient magnitude to affect appreciably the performance of a car under a given set of conditions of the vehicle or of the environment. Inasmuch as the calculations are simplified by doing so and because the difference between the amounts of deceleration and of power involved are small, the assumption is made that the maximum deceleration occurs when the wheels are locked, rather than when they are still rotating. The stopping-distances, theoretically obtained, apply to level-road conditions only.
1925-01-01
Technical Paper
250067
W L GILMORE
A racing airplane seems to possess a special quality that sets it distinctly apart from the conventional type of airplane; but, unless a person has at least dabbled in its design, he cannot realize the enormous amount of time, effort and ingenuity that has been expended by the designers who have made these super-speed airplanes possible. Therefore, an outline is given of the procedure adopted in designing and producing a specific model of racing airplane, as well as an outline of the yearly progress made in development. The first procedure is to allocate the work to the various members of the engineering organization. Finally, a type of design is chosen after a series of engineering conferences, and the design section studies the detail design of the component parts. A wing section that is adapted to the design already chosen is developed, and an accurate weight estimate is made of each unit part of the complete airplane.
1924-01-01
Technical Paper
240028
George J. Mead
ABSTRACT
1923-01-01
Technical Paper
230045
J W WHITE
Disc wheels are the answer to a demand for something better at a more reasonable price. The art of making wood wheels has been established, the machinery has become standardized and further reduction in cost is improbable; whereas the cost of suitable wood is steadily advancing and the trend, consequently, is upward. When the wire wheel was first introduced its use was a mark of distinction and to it can be traced the origin of the sport model, but its price cannot be reduced and it cannot compete, therefore, with the disc wheel on a price basis. The development of the disc wheel brought an equal distinctiveness of design and of pleasing appearance, but its progress has been different. The initial expenditure involved in the production of disc wheels is large; but the output also is large, and, as the volume increases, the prices become lower.
1923-01-01
Technical Paper
230004
THOMAS MIDGLEY, ROBERT JANEWAY
The authors present in this paper an explanation of gaseous detonation based upon what are considered incontrovertible laws, and show by the functioning of these well understood natural laws that gaseous detonation is a phenomenon that does not require any hypothetical assumptions to account for its existence. The physical conditions that must exist within an enclosed container when it is filled with an explosive mixture of gases and these gases are ignited are stated and analyzed mathematically, and an application of this analysis is made to the internal-combustion engine. The apparatus and the procedure are described inclusive of photographs and charts, and it is shown how the formulas can be applied (a) for constant throttle, by varying the temperature of the entering charge and (b) for constant temperature, by varying the throttle opening and the compression-ratio. The results are illustrated and discussed in some detail.
1923-01-01
Technical Paper
230029
E P Warner
The author discusses commercial-airplane design in general terms, considering the subject under the main divisions of economy, safety, speed and comfort. Under economy, mention is made of possible reductions of first cost by designing for long life and reliability, the effect of the former on the depreciation allowance being obviously advantageous. Airplane size is debated also, the trend of progress being seemingly toward the giant airplane. Safety is stated to be dependent upon reliability, structural strength, stability, control, fire prevention and reduction of risk of injury to passengers in the event of a crash. Minimizing the results of a crash is considered suggestively. Speed is governed almost solely by the ratio of wing loading to power loading; hence, speed will always be kept as low as possible without loss of business to competing transportation enterprises. Included among desirable measures to secure comfort are adequate ventilation and the elimination of noise.
1923-01-01
Technical Paper
230039
J G VINCENT, W R GRISWOLD
Stating the fundamental characteristics of the modern motor-car under the headings of performance, safety, economy, comfort and taste, the authors define these terms and discuss each basic group. The specifications of the car in which the single-eight engine is installed are given, and the reasons governing the decision to use an eight-cylinder-in-line engine are enumerated. Following a somewhat lengthy discussion of the components of engine performance, the design of the engine is given detailed consideration under its divisions of crankshaft design and the methods employed, gas distribution, the operation of the fuelizer, cylinders, valve gear and the arrangement of the accessories. Transmission design and the wearing quality of gears receive similar treatment.
1922-01-01
Technical Paper
220052
W L BEAN
The rail motor-cars now used by the New York, New Haven & Hartford Railroad are illustrated and commented upon, and statistical data regarding their operation are presented. The features mentioned include engine type and size, transmission system, gear-ratio, double end-control, engine cooling, heating by utilizing exhaust gases and exclusion of exhaust-gas fumes from the car interior. A table gives revenue data.
1922-01-01
Technical Paper
220054
CHARLES O GUERNSEY
1922-01-01
Technical Paper
220065
C N MONTEITH
The author presents, in outline only, the various features of airplane-development investigation that have been prosecuted. After mentioning the principal types of airplane designed and built shortly before the armistice and the types in service on the battle front at that time, four specific requirements for increasing the speed, the rate of climb and the ability to reach great altitudes are enumerated and commented upon, the further statement being made that an increase in performance can result from any one or from a combination of all four. Remarks upon design features are interspersed with the discussion of performance improvements, brief explanations being given of the variable-area and the variable-camber-wing schemes, the idea of having a thick wing-section with trailing and leading edges hinged, and that of modifying the wing-section by making the leading edge a small detachable airfoil that can be shifted.
1921-01-01
Technical Paper
210053
CHARLES O GUERNSEY
The majority of the reputable truck builders are attempting to build a high-quality product that will operate over a period of years with the minimum of maintenance expense; however, many designers lose sight of the effect of shocks and strains, which is of even greater importance. Stating that a truck is scrapped for some one or a combination of the three reasons of obsolescence of design, wear on vital parts that cannot be replaced economically and failure of parts due to shock loads, fatigue or crystallization, the author comments upon these and then discusses chassis strains under five specific headings, illustrations also being given.
1921-01-01
Technical Paper
210060
G J MEAD, L E PIERCE
In discussing the probable trend of aeronautical powerplant development and subsequent to a brief survey of the present situation, the authors review the evolution of various engine types and analyze the effect of their characteristics on airplane performance, considering also the proper installation of airplane powerplants. The problem now confronting the industry is one of establishing standard types for the powerplants required by each service and setting up reasonable power requirements for each unit. For each service, factors must be developed to permit the making of correct comparisons of the performance of the different engines. The future types of engine are considered at some length and special reference is made to radial engines. Curves and tabular data accompany the discussion of variations in engine elements and the characteristics of a high-speed airplane are treated in a similar manner.
1920-01-01
Technical Paper
200024
ALEXANDER KLEMIN
Viewing 33091 to 33120 of 33174