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1924-01-01
Technical Paper
240028
George J. Mead
ABSTRACT
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.
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.
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.
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
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
200074
GEORGE J MERCER
The author presents the practical side of the body designer's work and refers to him as being between the office and the shop, the one who stands in the way of the impatient man that wants action without preparation. The development of the body designer and body designing is reviewed and the position and duties of the designer are stated at some length. The design factors are considered in detail and the making and utilization of wax models are described, followed by a lengthy consideration of curved-surface bodies, wood body frames, style and body types. The fittings and minor design details are discussed and future designs predicted from present indications. The author explains the body designing business in detail to refute the suspicion that the working methods of body designers are different from those employed by the other members of an engineering force because body designing is different and distinct from the other branches of motor-car engineering work.
1920-01-01
Technical Paper
200072
F M LEWIS
Vibrations of several kinds can occur in crankshafts, but the principal ones are transverse and torsional; the paper deals entirely with the latter. A simple case of torsional vibration is considered first and the principles are applied to the torsional vibration of a shaft, the argument being carried forward at some length. A discussion of critical speeds follows and this is supplemented by a lengthy mathematical analysis, inclusive of diagrams. Calculations were made to determine the period of the shafting of United States submarines S4 to S13 and these are described. The three cases investigated include the charging condition when the engine is driving the dynamo, the after clutch being disconnected; the surface condition, when the engine drives the propeller; and the submerged condition, when the motors drive the propeller, the forward clutch being disconnected. Calculations were made also with a Sperry magnetic clutch substituted for the usual flywheel and clutch.
1920-01-01
Technical Paper
200003
WILLIAM BREWSTER
The author first considers the style and arrangement of the seats, the position of the rear axle as affecting the rear kick-up in the chassis frame, and the position of the rear wheels as determining the distance from the back of the front seat to a point where the curve of the rear fender cuts across the top edge of the chassis frame. The location of the driver's seat and of the steering-wheel are next considered, the discussion then passing to the requirements that affect the height of the body, the width of the rear seat, and the general shape. The evolution of the windshield is reviewed and present practice stated. Structural changes are then considered in relation to the artistic requirements, as regards the various effects obtained by varying the size or location of such details as windows, doors, moldings, panels, pillars, belt lines, etc., and the general lines necessary to produce an effect in keeping with the character of the car.
1920-01-01
Technical Paper
200031
C M McCreery
After stressing the importance of transportation, the possible uses of the motor truck are considered. The increased cushioning and traction obtained from pneumatic truck tires accomplish faster transportation, economy of operation, less depreciation of fragile load, easier riding, less depreciation of roads and lighter-weight trucks. These six advantages are then discussed separately and various data to substantiate the claims made are presented. Following detailed consideration of transportation and operation economies, and depreciation of loads and roads, the practicability of pneumatic tires is elaborated, and wheels, rims and tire-accessory questions are studied. The four main factors bearing upon truck design for pneumatic tires are stated and discussed; emergency equipment for tire repair is outlined and a new six-wheel pneumatic-tired truck is described.
1920-01-01
Technical Paper
200024
ALEXANDER KLEMIN
1920-01-01
Technical Paper
200026
SAMUEL R PARSONS
The paper defines properties that describe the performance of a radiator; states the effects on these properties of external conditions such as flying speed, atmospheric conditions and position of the radiator on the airplane; enumerates the effects of various features of design of the radiator core; and compares methods that have been proposed for controlling the cooling capacity at altitudes. Empirical equations and constants are given, wherever warranted by the information available.
1920-01-01
Technical Paper
200065
A L PUTNAM
Although disc wheels have not been produced in such great quantities as some of the other types, they have advanced far enough in practical application to demonstrate their possibilities and fundamental correctness. Distinction should be made between the wheel itself, the single-taper dished disc and other features such as tire, rim and hub applications. Single-taper dished-disc wheels were developed in France and in this country at about the same time but, on account of the variation in European and American tire practice, the resultant wheels took different forms. The author describes these forms and comments upon them, the argument being favorable to the single-taper disc, and the statement is made that, given the data as to the service expected, the weight and power of the car, the single-disc wheel will compare favorably with any other type, since, when properly designed, the strains are diffused over the entire surface.
1920-01-01
Technical Paper
200048
THURMAN H BANE
The author describes the Air-Service work at McCook Field, presenting and describing numerous types of airplane, airplane engine and auxiliary aviation apparatus. After reviewing the development and present status of the Air Service, he describes the airplanes developed during the war and comments briefly upon their chief characteristics, referring to the illustrations; airplane engines are treated in a similar manner. Among auxiliaries, mention is made of airplane armament, synchronizing outfits, parachutes and packs, machine-guns, bombs, cameras and photographic equipment, with comment upon their usage and characteristic features. Armored airplanes are considered specifically and the use of variable-pitch propellers exemplified. The relations of military and commercial aviation are stated and the possibilities of airplane transport and airplane hospital ambulance service are mentioned.
1919-01-01
Technical Paper
190024
CORNELIUS T MYERS
1919-01-01
Technical Paper
190026
C H DAY
1919-01-01
Technical Paper
190031
A F MILBRATH
THE design of a modification of the Class B Government standardized truck engine is presented, the principal object being a saving in weight without sacrificing either durability or safety factors. The crankcase design is rigid, but the metal is distributed so that the weight will be a minimum. The crankshafts are made of chrome-nickel steel of an elastic limit of 120,000 lb. per sq. in., which further carries out the idea of durability with low weight. The connecting-rod length is slightly more than twice that of the stroke, and this, with light-weight pistons, obviates vibration, without adding weight to the engine on account of increased cylinder height. The flywheel and bell-housing diameters were selected with a view to securing enough flywheel weight for smooth running without increasing the engine weight materially. All-steel supports reduce breakage of arms to a minimum. The manifolds are carefully designed to give economical performance, even with low-grade fuels.
1919-01-01
Technical Paper
190032
OTTO M BURKHARDT
SOME practical examples of correct as well as of incorrect methods of designing are studied, using a motor vehicle for illustration. The mechanism of such a vehicle should be very simple, and the elimination of certain links and members here and there may become more or less desirable. It is essential to know how much this will burden other members, and what strengthening or even redesigning may become necessary. It has been proposed to eliminate the torque and radius-rods. By formulas and drawings the author shows how complex the problem is and the various changes that must follow such an attempt. A vehicle must have much stiffer springs if the torque rod is to be eliminated. This inevitably leads to a study of springs and of the influences of brakes. A vehicle can be operated at somewhat higher speed with a torque-rod.
1919-01-01
Technical Paper
190007
O E HUNT
THE impression that recent aircraft experience should have taught engineers how to revolutionize automobile construction and performance, is not warranted by the facts involved. Aircraft and automobiles both embody powerplants, transmission mechanisms, running gear, bodies and controls, but their functions are entirely different. The controls of an airplane, except in work on the ground, act upon a gas, whereas with an automobile the resistant medium is a relatively solid surface. Similarly, the prime function of the fuselage is strength, weight considerations resulting in paying scant attention to comfort and convenience, which are the first requirements of an automobile body. Aircraft running-gear is designed for landing on special fields, and is not in use the major portion of the time. The running-gear is the backbone of an automobile, in use continuously for support, propulsion and steering; hence its utterly different design.
1919-01-01
Technical Paper
190065
R H UPSON
Airships were not generally considered important before the war. Many thought they would never become practical as a means of transportation. The proper conception of what an airship is having first been explained, the three principal ways in which progress has been made are specified as weight-saving, improvement of overall propulsion efficiency and decreasing resistance and increase in size. The last mentioned feature is discussed in some detail, the conclusion being that practically anything is possible, given an airship of sufficient size. The future needs of airship development are then considered, such as more suitable engines, multiple powerplants, dependability, the development of better fabric and better landing and hangar facilities.
1919-01-01
Technical Paper
190062
N L LIEBERMAN
1919-01-01
Technical Paper
190056
J C HUNSAKER
Naval aircraft are distinctively American types. Only one foreign seaplane was copied by the United States during the war, and when finally put into production it resembled the British prototype in externals only. While the Navy does a large part of its own designing and building through a corps of naval constructors, its theory of manufacture is to assemble parts procured from separate makers, and private design and construction are encouraged by contracting with builders. Available talent both in and out of the service and the facilities of parts makers, the new materials developed during the war and organized engineering which drove the entire process toward speedy results were appropriated by the Navy. The NC flying boat is typical of U. S. Navy practice. In the same way the dirigible C-5 is a purely American type. The development of really large flying craft before 1917 was held back because no suitable engine had been designed. When the 350-hp.
1919-01-01
Technical Paper
190055
F C GOLDSMITH
1919-01-01
Technical Paper
190049
E H BELDEN
Efficiency, appearance and comfort will be the catchwords of the car of the future. Extreme simplicity of chassis will be needed to reduce weight and permit the use of substantial sheet-metal fenders, mud-guards and bodies. The center of gravity should be as low as possible consistent with good appearance. For comfort the width and angle of seats will be studied more carefully and the doors will be wider. A new type of spring suspension is coming to the fore, known as the three-point cantilever. Cars adopting it will have a certain wheelbase and a longer spring base. A car equipped with this new mechanism has been driven at 60 m.p.h. in safety and comfort without the use of shock absorbers or snubbers. It is the opinion of the author that this new spring suspension will revolutionize passenger-car construction.
1919-01-01
Technical Paper
190044
LEWIS P KALB
The paper treats the subject of ability from the point of view of its relation to the present trend in motor-truck design, setting forth some of the fundamental considerations involved. An ability formula when applied to automotive vehicles is to determine a “factor of experience” from which engine sizes and gear ratios can be calculated. While passenger-car performance is measured in terms of speed and acceleration, the latter are not the most important considerations in motor trucks, the speed of which is limited by the use of a governor. Wind resistance also is negligible at truck speeds. Practically the only resistances to be overcome by a motor truck are road friction and the force of gravity. Both road and grade resistance are in direct proportion to weight carried and are usually expressed in terms of pounds per pound.
1918-01-01
Technical Paper
180014
J EDWARD SCHIPPER
Viewing 33361 to 33390 of 33425