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Viewing 16501 to 16530 of 16558
1934-01-01
Technical Paper
340070
LOUIS WAIT
1933-01-01
Technical Paper
330003
A. L. MacClain, D. S. Hersey
THE purpose of this paper is to show that the value of commercial flight-testing depends largely upon the utility, reliability and accuracy of the equipment and instruments employed. In general, it is found that improvements in these three factors depend largely on the simplicity of the apparatus used. Special engine-tests have led to the development of instruments and apparatus not commonly available commercially, and the use of these has made it possible to employ the aircraft engine as an instrument for the measurement of power in flight. This ability to measure power has led to the development of a method of making comparative engine-temperature and other tests which eliminates or corrects for a number of the major variables ordinarily affecting such tests. Because of the increasing popularity of the controllable-angle propeller, tests are also described which enable one to determine the value of such a propeller when only an adjustable-angle propeller is available.
1933-01-01
Technical Paper
330011
E. E. Wemp
Summary FIRST consideration is given by the author to basic improvements in clutches of the lever-release single-plate and to those of the two-plate types. He emphasizes that the severity of clutch service has increased very materially in the last few years and that the increased clutch duty of today is further augmented by the car manufacturer in providing cars having greater acceleration and higher torque, particularly at the higher speeds and usually without a proportionate increase in clutch size. Developments along logical lines which have resulted in improvements in design are cited as being (a) the design of the driven disc and the selection of facings, to produce improved engagement and greater life; (b) design of the cover-plate assembly to permit higher spring pressure with less retracting movement of the pressure plate; and better selection of facing and pressure-plate materials to reduce facing wear and pressure-plate distortion or scoring.
1932-01-01
Technical Paper
320036
D. A. Dickey, O. R. Cook
THE DEMAND for a successful controllable or automatic propeller is greater today than ever. Such a propeller will enable commercial aircraft to take off safely with greater loads, and it may enable multi-engine airplanes that cannot now maintain altitude with one engine dead to do so with a safe margin of power. For military aircraft it means increased rate of climb and increased speed at altitude, especially with supercharged engines. To obviate confusion in nomenclature, the authors give definitions of adjustable, controllable and automatic propellers. Distinction is drawn between the needs of different classes of airplane for different types of changeable-pitch propellers. Many propellers falling within the several classes have been designed but few are in use. Cost, weight and complication are obstacles to their commercial success. Several problems still confront the designer in this field, the chief one being that of obtaining material that is sufficiently light and strong.
1932-01-01
Technical Paper
320043
Ralph H. Upson
BLIND flying without special training, together with general improvement in flight control, is possible with a new simplified type of artificial horizon. The instrument in most respects provides a safer reference for control than does the natural horizon, because it deals directly with the real source of control, which is the air. Air is to the airplane as the road to an automobile; the different movements of the airplane relative to its own road of air primarily determine its control. To make such movements visible is a function of instruments, but a set of several different instruments to show separate movements of the airplane is unnecessarily complicated and expensive. A single instrument giving the unity and simplicity of the natural horizon but having a directness of reading that can be obtained only from the directly adjacent air is the remedy.
1932-01-01
Technical Paper
320042
Harold Gatty
HEREIN the author describes methods and shows instruments, tables, scales and curves used for air navigation. The ground-speed-and-drift meter devised by him and used with such remarkable success in the round-the-world flight with Wiley Post in less than nine days, on which the author was navigator, is illustrated and described. Much has been accomplished in the last few years in providing methods and equipment for quickly and accurately determining the position and laying the correct course of aircraft, but considerable improvement remains to be made in instruments, particularly sextants. No one method of navigation can be used under all conditions; a combination of four is necessary to achieve the best results.
1931-01-01
Technical Paper
310036
Stephen J. Zand
AIRPLANE vibration produces many undesirable conditions during flight, such as fatigue of structural members, a bad effect on the nervous systems of the occupants and the like. Excessive vibration leads to premature deterioration or to erroneous indications of instruments. Vibrations can be analyzed from a mathematical viewpoint with gratifying results, but such analysis is sometimes difficult and often is applicable only to selected conditions. A serious mathematical analysis was carried out in the investigation of resonance conditions between engine and engine mount. Then the problem was approached from a rather empirical viewpoint to give vibration relations, not, as heretofore, to bodily sensation, but to such terms as amplitude, frequency, the relation between the two, form and the like.
1929-01-01
Technical Paper
290049
MICHAEL WATTER
THE causes and nature of the spinning of an airplane, and measures for the prevention of and recovery from a spin, are discussed. Tests and analysis are said to have shown that spinning is a stable motion of rotation, and that the real dangers are in its instability. Recovery from a spin is held to be more important than prevention, as complete knowledge of means of recovery will lead to mastery of the whole phenomenon. The spinning motion is a combination and balance of aerodynamic and purely dynamic forces and couples, asserts the author. Full-scale experiments prove beyond doubt that side-slip may be very pronounced in a spin, which changes considerably the rate of roll of the simple autorotational kind. The rolling of the wings leads to the establishing of a yawning couple which may become dangerous, tending to keep the craft in a spin because of the increased shielding of the tail surfaces.
1929-01-01
Technical Paper
290061
T. P. WRIGHT, W. R. TURNBULL
1928-01-01
Technical Paper
280018
JOHN SNEED
THE theory and characteristics of brakes of the Steeldraulic system are set forth and their application in practice is explained. Self-energizing brakes are said to be desirable because they allow large clearances, low pedal-effort and frictional coefficient and, if properly designed, give a high degree of efficiency with smooth uniform action. To accomplish these results, the controls should deliver equal and accurate actuation to all brakes at all times, be designed to minimize the possibility of becoming inoperative on account of dirt and rust, require no servicing, be noiseless and of good appearance, and remain unaffected by climatic changes. Shoe design should allow very liberal limits and tolerances in wheel, axle and drum assemblies, without causing erratic brake-action or noises. The brake hook-up should follow the simplest line and use the least number of connecting links.
1928-01-01
Technical Paper
280019
NEWTON F. HADLEY
AN effort is made to determine the essentials of an ideal shock-absorber and to describe the types that approach or depart from this ideal. Mathematical analysis is not used, but judgment is based on the experience of the author with various types. The requirements of a satisfactory shock-absorber are defined and the methods used by the author in culling out certain shock-absorbers that fail to meet these requirements are outlined. By means of a machine based on the principle, of a steam-engine indicator, the energy required to move a shock-absorber throughout its cycle at varying speeds is measured and charts are obtained. When these charts are compared with a characteristic shape of diagram of a shock-absorber found from repeated trials on the road to give the most satisfactory riding, the merits or shortcomings of any other shock-absorber can be deduced from the difference in shape.
1927-01-01
Technical Paper
270001
C. S. CRAGOE, J. O. EISINGER
PREVIOUS papers relating to the cooperative fuel-research investigation of engine-starting have attacked the problem along two distinct lines, namely, (a) by actual tests of the time required to start engines under various conditions, such as temperature, mixture supplied and the like, using different fuels; and (b) by laboratory tests of the volatility of the same fuels under somewhat similar conditions, using the method of equilibrium air-distillation. In this paper the results of these two methods of attack are correlated. For this purpose, it was necessary to extend the air-distillation data to lower temperatures than had been used in the tests. This involved an application of the laws of the perfect gas and the well-established law governing the relation between vapor pressure and temperature. The results of the engine tests were originally plotted with the rate of fuel supplied, as ordinate, and the time required to start, as abscissa.
1927-01-01
Technical Paper
270002
G. L. CLARK, A. L. HENNE
DETAILS are given of the method of control of the engine so that quantitative and reproducible measurements of detonation and comparisons with spectra can be made. Typical data are tabulated and photographs are shown of the free-burning flames of hydrogen, carbon monoxide, methane, gasoline in a blow-torch, and the like. The spectra of explosion and of detonation in the engine confirm earlier conclusions. By means of a synchronous shutter, the spectra of radiation during the four quarters of a stroke are obtained for straight-run gasoline under detonating and non-detonating conditions for the same fuel containing tetraethyl lead, aniline and iodine as knock suppressers and for cracked-gasoline blends. The outstanding result is that, during detonation, the first-quarter spectrum extends far into the ultra-violet, that of the second quarter, a somewhat less distance; the third and fourth quarters are characterized by very little radiation energy.
1927-01-01
Technical Paper
270074
A. F. HEGENBERGER, BRADLEY JONES
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.
1926-01-01
Technical Paper
260001
John O. Eisinger
ABSTRACT
1926-01-01
Technical Paper
260024
H M CRANE
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
250028
JOHN O EISINGER
Recent work in connection with the Cooperative Fuel Research is discussed in the paper, which presents data obtained as a result of the recommendation of the steering committee “that the factors contributing to easy starting be investigated.” It refers first to preliminary work discussed in previous reports, and then describes the test set-up. This was much the same as that used in the crankcase-oil-dilution tests, the chief difference being the replacement of the carbureter by a single jet mounted in a vertical pipe. The arrangement was such that changes in jet size, jet location, rate of fuel flow, throttle opening and choke opening could be obtained easily. Provision was made for measuring the amount of fuel used in starting. The test procedure consisted in driving the engine by the dynamometer until conditions became constant, then in turning the fuel on and noting the time required for starting and the amount of fuel used.
1925-01-01
Technical Paper
250024
J H HUNT, G F EMBSHOFF
Electrical instrumentation for research work has been developed to a high degree because of the great speed of action and the convenience of application of the electric current. The current serves to transmit instantly to a recording instrument the impulses imparted to it by a detecting device. There is available a great wealth of indicating, integrating and recording devices that can be used readily for automotive research by the aid of auxiliary devices, some of which can be purchased and some of which can be easily made in any ordinary model shop or toolroom. In the study of automotive mechanism the research engineers have drawn upon the investigation work of men in other lines of industry and have found it necessary to go back of these men to the scientific investigators who are attacking the elements of various problems in the physical and chemical laboratories.
1925-01-01
Technical Paper
250001
S W SPARROW, J O EISINGER
This report deals with further progress in the cooperative fuel-research. General factors underlying starting ability are discussed and experiments showing the effect of changes in spark character and of gas leakage are described. The probable mechanism of crankcase-oil dilution is treated, and further experiments with reference to this subject are explained. One experiment deals with operation with oil as a cooling medium to obtain high jacket-temperatures. Other experiments show the effect of change in piston clearance and in the number of piston-rings employed. Factors influencing the rate at which the diluent is eliminated from the diluted oil are shown to be of importance, and methods of examining these factors are stated.
1925-01-01
Technical Paper
250006
DALE S COLE
Progress made in the development of electrical equipment to serve adequately the needs of motorcoach service is reviewed. Electrical loads on motorcoaches are comparatively high, including the usual head, tail and dash lamps, body-marking and destination lamps and buzzer systems. As more and more electrical energy is used, the source of supply and its control become relatively more important. Not only does the electric generating system have to meet the demands of battery charging, but it should be able to carry the connected load with no battery in the circuit. This means that not only is sufficient energy necessary, but the voltage must be regulated in such a manner that the battery can be charged without endangering the life of the lamps because of excessive voltage, and no flicker in the light from the lamps must be perceptible. All these results must be attained under conditions of variable load, variable speed and the changeable temperatures encountered in service.
1925-01-01
Technical Paper
250044
J R CAUTLEY, A Y DODGE
Because of the increase of traffic on the highways in the last few years, retardation has become the most vital function of car operation; and safe retardation is as necessary as rapid retardation. Good brakes are as essential as a good engine. Becoming convinced of the many attendant advantages of four-wheel brakes, the authors began an intensive study of braking, the results of which are outlined. The features of construction of the Bendix-Perrot standardized four-wheel braking-system, which include: (a) standardized and improved controls, (b) standardized brakeshoes and (c) a simplified brake-operating layout or hook-up, are described and illustrated and the advantages to be obtained with these improvements are summarized.
1924-01-01
Technical Paper
240047
W C BROWN
General considerations that affect the attainment of adequate lighting are mentioned, it being stated that proper lighting of the interior of a motorbus is influenced by limitations peculiar to the service, such as vibration, scant headroom, a restricted energy supply and relatively large voltage-variations. Available types of bus-lighting equipment are analyzed as to their suitability, from six different standpoints that are stated. “Glare” is defined and means of obviating it are suggested, inclusive of a discussion of desirable types of finish for the interior with regard to reflecting surfaces. The severe vibration produced by many motorbuses demands head-lamps of more rugged construction than that used for the headlighting of private cars. Eight essentials for motorbus head-lamps are specified. A very large percentage of the glare and poor illumination of the motor vehicles on the roads results from improper adjustment or the lack of any means for adjustment of the head-lamps.
1922-01-01
Technical Paper
220003
THOMAS MIDGLEY, W K Gilkey
The paper is intended to familiarize automotive engineers with the general subject of spectroscopy, by pointing out the various methods that can be employed to determine the actual instantaneous pressures obtained in normal combustion, the temperature-time card of the internal-combustion engine and the progress of the chemical reactions involved in normal and abnormal combustion. The subject of spectroscopy is outlined and explained, illustrations are presented of different types of spectra, and spectroscopes and their principles are discussed. The remainder of the paper is devoted to an outline of what the spectroscope can reveal about the nature of combustion.
1921-01-01
Technical Paper
210001
H W Alden
The author brings to attention very emphatically the responsibility of the automotive industry for some things besides the actual building and selling of motor cars. The progress of civilization can be measured very largely by advances in means of communication. The transfer of messages by wire and wireless has made wonderful advances of a fundamental nature in recent years, but the transportation of commodities from place to place has not made such strides. The automotive industry has been concerned mostly with the actual development and production of the motor car and, as an industry, has stopped there without developing those allied activities which are vital to the long-time success of the business. The railroads afford a good example to follow in principle.
1921-01-01
Technical Paper
210037
L M WOOLSON
Abstract The general requirements for ideal carburetion are considered first, as an introduction to what the Packard fuelizer is and how it functions. Since it is difficult to secure uniform distribution with what is termed a wet mixture, this problem is discussed in general terms and it is stated that the fuelizer was evolved only after several different types of exhaust-heated manifold had been tested and found wanting. Detonation is treated at some length, four specific rules being stated that apply to the most desirable mixture temperatures to be maintained, and the source of the ignition spark for the fuelizer is discussed as an important element in the device. Further consideration includes comments upon the comparative merits of the hot-spot and the fuelizer, “hot-spot” being intended to mean any of the exhaust-heated manifold-designs in which the heat is more or less localized.
1920-01-01
Technical Paper
200062
A D T Libby
A discussion of the advantages of magneto ignition resolves itself into a comparison of magneto and battery-ignition systems, resembling early discussions of the relative merits of the direct and the alternating-current electric systems; both are in existence and fulfilling their respective parts. After stating that ignition is closely related to carburetion and generalizing on the subject of ignition, the author discusses the fundamentals of ignition systems at length, presenting numerous diagrams, and passes to somewhat detailed consideration of comparative spark values, using illustrations. Storage batteries and auxiliary devices receive due attention next and numerous characteristic curves of battery and magneto ignition are shown. Impulse couplings are advantageous in starting large truck and tractor engines, which generally use magnetos; these are described.
1919-01-01
Technical Paper
190069
J H HUNT
Manufacturers of carbureters and ignition devices are called upon to assist in overcoming troubles caused by the inclusion of too many heavy fractions in automobile fuels. So far as completely satisfactory running is concerned, the difficulty of the problem with straight petroleum distillates is caused by the heaviest fraction present in appreciable quantity. The problems are involved in the starting, carburetion, distribution and combustion. An engine is really started only when all its parts have the same temperatures as exist in normal running, and when it accelerates in a normal manner. Two available methods, (a) installing a two-fuel carbureter, using a very volatile fuel to start and warm-up the engine, and (b) heating the engine before cranking by a burner designed to use the heavier fuel, are described and discussed.
1919-01-01
Technical Paper
190064
D W DOUGLAS
The factors included in the commercial airplane problem are the practical use that can be made of airplanes, the volume of business that can be expected, the necessary changes from present military types to make an efficient commercial airplane and what the future holds for this new means of transportation. The requirements for passenger transportation, airmail and general express service, are first discussed in detail, consideration then being given to other possibilities such as aerial photography and map-making, the aerial transportation of mineral ores, sport and miscellaneous usage. Changes in the present equipment of engines and airplanes to make them suitable for commercial use are outlined, and special features of aerial navigation, landing fields and legal questions are mentioned.
Viewing 16501 to 16530 of 16558