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Viewing 109741 to 109770 of 110622
1925-01-01
Technical Paper
250055
W D'A Ryan
Although agreeing in general with the sentiments expressed by Mr. Crane and Mr. Hunt, exception is taken to the statement that the solution of the headlighting problem is to be found in diffused lighting, because it has not sufficient range, is too glaring and is too dangerous in a fog. The trouble is said to lie not in the specifications but in the devices that they are supposed to cover. Suggestions are offered regarding modifications that might advantageously be made in the present specifications, and a detailed summation is given of the requirements considered essential to a first-class headlight. The statement is added that a headlight embodying all the points enumerated, while at the same time using a 21-cp. bulb, has already been perfected.
1925-01-01
Technical Paper
250054
J H HUNT
Two points are cited as illustrating the difficulty of enforcing the present regulations, namely, (a) the variation in the angle of the headlight beam caused by the compression of the springs when the loading of the car is changed from no load to full load and (b) the variation of the tilting of the beam caused by the pitching of the car on an ordinary road, the effect being similar to that produced by flashes of lightning in a pitch-dark night. Denial is made of the author's alleged advocacy of diffused lighting and comparison is made of the distribution-curves obtained with frosted bulbs and those obtained with fairly good lamps conforming to the Society's specifications.
1925-01-01
Technical Paper
250053
H M CRANE
After referring to the recommendations made to the National Conference on Street and Highway Safety by the Committee on Motor Vehicles and the Committee's further explanation of the recommendations, the author amplifies more fully the difficulties that have arisen in the operation of the system of headlight regulations sponsored by the Illuminating Engineering Society and this Society and suggests a line of fundamental research with a view to drafting more desirable regulations. Inasmuch as road conditions have changed greatly since the regulations at present in force were first proposed, he believes that a new study of the subject might result in marked improvement. Definite control of a concentrated headlight beam, deflected below a horizontal line, as originally proposed by the Society, failed to produce the desired result, and the next step was the formulation of the regulations listed in the S.A.E. HANDBOOK.
1925-01-01
Technical Paper
250052
H C MOUGEY
Public demand for more durability in automobile finishes has led to new developments in finishing materials and methods through cooperation of finishing materials manufacturers and automobile builders. By experimentation it has been found that certain cellulose nitrate materials, when applied over suitable under-coats, dry quickly in the air by evaporation of the solvents and leave a film that is hard and tough. Its durability is many times greater than that of the most durable finishing-varnish and, as it has been discovered that sufficient luster can be produced by rubbing and polishing the unprotected cellulose-nitrate surface, one of the large automobile production plants adopted, in July, 1923, as its standard method of finishing, the use of such a finishing coat over primer and surfacer coats, obtaining the luster by polishing the cellulose-nitrate top-coat. A number of companies have now adopted this process.
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
250050
HENRY S BALDWIN
Development of the uses of electricity having begun approximately three decades ago, about the time that the automobile made its appearance, the application of electricity to the needs of the automobile has enabled manufacturers to meet the demands of the public for its production. When electricity was applied to starting the internal-combustion engine and to lighting the automobile 15 years later, the popularity of the automobile greatly increased. Now, 5 per cent of the weight and nearly 10 per cent of the selling price of a five-passenger sedan represent electrical apparatus that adds to the comfort and convenience of the public.
1925-01-01
Technical Paper
250049
A F MASURY
Reviewing the present transportation problem in regard to its demand for larger motor-vehicle units of transport, the author says that the motor truck is proving to be successful in the movement of practically all local freight and that the motorcoach is meeting with greater and greater favor as the logical vehicle with which to meet the demands of the traveling public for better transportation facilities. Although the present types of motor vehicle are serving present needs in a more or less successful manner, when strict economics becomes the standard for measuring road transportation a demand will be made for vehicles that will accommodate the maximum freight or passenger loads in the minimum of street space. At speeds governed within limits of safety they will offer the utmost comfort for passengers and will haul perishable goods over long distances in quantities large enough to assure strictly economic operation.
1925-01-01
Technical Paper
250048
J W WHITE
Experiments with hydraulic steering-control with the object of preventing or reducing shimmying and tramping were made by the author, who asserts that the elimination of backlash by doing away with mechanical joints and by holding the front wheels as rigid as the rear wheels has been amply proved by the results to be a long step in the right direction. With a Marmon car fitted with an hydraulic steering-system and driven over the roughest roads it was impossible to discern any front-wheel wabble as the car approached and passed the observer.
1925-01-01
Technical Paper
250047
R W BROWN
Inasmuch as the forces that act when a vehicle passes over a road obstruction are very complex, comparative analysis of the riding-qualities of the different parts of a vehicle is difficult; hence, to obtain even an approximation of them, measurement of the different displacements that occur must be confined to a given representative condition or series of conditions. The displacement that causes the most discomfort to a passenger is probably that which takes place in a vertical plane. Its three leading characteristics are the amplitude of the vertical movement, the velocity of the motion and the rate of change of the velocity. Of these the last mentioned is the most important. It is sufficiently exact to assume that tires and springs which reduce motion increase riding-comfort.
1925-01-01
Technical Paper
250046
F C MOCK
Riding-discomfort from road inequalities can be divided into two general classes, of which the first, direct discomfort, includes jolts, jars and unpleasant forces that occur during, and as the immediate result of, passage over the inequality. The extent of these discomforts depends chiefly upon the magnitude of force exerted against the passenger and the rate at which this force is applied. The second type of discomfort may be called potential and includes such motions of the car, following, and resulting from, passage over the road inequality, as lead to “not holding the road,” extreme pitching motion, or throwing the passengers off the seat and the like. This potential discomfort is more or less proportional to the amplitude of spring motion and the extent to which this motion interferes with the uniform straight-forward progression of the car. The springs of a vehicle supported at the front and the rear seldom operate individually.
1925-01-01
Technical Paper
250045
H E MAYNARD
The principles of hydraulics have long been known and the use of a liquid for transmitting power has proved safe and reliable in many applications, notably in the operation of passenger elevators. Hence it was natural to make use of these principles in a device for controlling an automobile under traffic conditions that demand an efficient and dependable braking mechanism. The ideal of equalized braking-effort is sought but variation in the coefficient of friction between brake-bands and brake-drums and between tires and road introduces complications, so we must be content for the present with the nearest possible approach to equalized pressure at the brake-bands. In the hydraulic system, pressure is transmitted equally throughout the liquid and to the levers that actuate the brake-bands. These levers are also designed to transmit the pressure equally to the brake-bands on all four wheels.
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
250041
E E WEMP
Reviewing briefly the history of the automotive clutch and summarizing the most interesting achievements in clutch design during recent years, the author discusses friction facings and says that the development of the asbestos-base friction-bearing has made possible the multiple-disc dry-plate and the single-plate types. For severe service, the qualifications of a satisfactory friction-facing are density of structure, together with a reasonably high tensile-strength; the coefficient of friction should be high and fairly constant over a wide range of temperature; the facing must be able to withstand high temperature without deterioration; the impregnating compound must not bleed out at high temperature; and the permeation of the impregnating solution must be complete so that the wear resistance is constant throughout the thickness of the facing. The molded and the woven types of facing are treated at length.
1925-01-01
Technical Paper
250040
EARLE BUCKINGHAM
Discordant sounds from transmission gears can be avoided by using gear-tooth ratios that give pleasing combinations of tones; a 5:6 ratio produces a minor third note; a 4:5 ratio, a major third; a 2:3 ratio, a perfect fifth; and a 2:1 ratio, an octave. Careful attention to selection of relative tooth-numbers, therefore, will aid greatly in the production of quiet or un-objectionable transmissions. Careful design and accuracy in the production of gears will not, alone, insure quiet operation; the shafts must be sufficiently rigid to hold the gears in proper operating position and large flat surfaces in transmission cases, which act as sound amplifiers, should be avoided. Bearings may also be noisy through faults of their own or because of improper mounting and alignment.
1925-01-01
Technical Paper
250038
PHILIP L SCOTT
What the Diesel engine has done, its possibilities of development and future application to automotive service are major topics of the paper. When modified for automotive use, the author asserts that the Diesel engine would not only allow the burning of cheaper fuel and provide greater fuel economy, but give immediate opportunity to use the two-stroke cycle; that is, it would generate about twice the power for an equal weight of mechanism, compared with present power attainment. In addition, the two-stroke cycle makes possible partial or entire elimination of exhaust-valves, exhaust through ports being better in every respect, and the Diesel-engine principle affords the possibility of a two-stroke-cycle double-acting engine in which, theoretically, four times the power of the present gasoline engine would be available.
1925-01-01
Technical Paper
250039
P M HELDT
If automobile builders had available a variable transmission that was capable of giving any ratio between the upper and the lower limits and that substantially was equally satisfactory at all ratios from the viewpoint of efficiency of transmission, wear and quietness of operation, a comparatively large reduction-ratio would be used most of the time, because that would assure the greatest fuel-economy. Several types of continuously variable gears have been used on automobiles, or merely suggested for such use. Of these, the systems employing belts and friction discs or wheels need hardly be considered at present, because of their bulkiness and comparatively low efficiency.
1925-01-01
Technical Paper
250036
T A BOYD
As the automobile, a chemical factory on wheels, converts gasoline and air into energy for propelling itself and its load, its prinicpal problems of operation center on the properties and impurities of the raw materials, the utilization and disposition of the by-products and the proper maintenance of the plant equipment. After discussing the nature of gasoline, the author enumerates the five sources from which motor fuel is derived. The major part of the gasoline is said to be obtained directly by distillation from petroleum; about one-quarter of American gasoline, to be secured by the cracking of heavier petroleum oils; about one-tenth, to be gasoline that is separated from natural gas; from 1 to 2 per cent, to consist of benzol and similar material; and fuel used in some sugar-producing localities, to comprise alcohol made from molasses.
1925-01-01
Technical Paper
250037
ALEXANDER HERRESHOFF
Piston friction is much the largest item of mechanical loss in an engine, amounting to fully one-half the indicated horsepower at light loads. Although opinions differ as to the most desirable temperature of the jacket-water for full-load operation, no question has arisen as to that for part load. It should be as high as possible, in order that piston friction can be reduced by keeping down the viscosity of the oil on the bearing surfaces, and that complete vaporization of the fuel may be secured. By reducing the friction of the piston and improving the vaporization, steam-cooling increases economy, which, on a number of cars of different makes, has been found to average 20 per cent more miles per gallon. Water is practically a non-conductor of heat. Boiling water, or a mixture of water and steam, is far more effective for cooling than is water that is not boiling.
1925-01-01
Technical Paper
250034
LAWRENCE T WAGNER
Effects of engine operation on the lubricating oil used in it determine to a large extent the ability of the oil to maintain continuous lubrication and, consequently, of the engine to function efficiently. Engine operation has three major effects on the oil: (a) complete destruction of part of the oil, (b) physical and chemical changes in the oil and (c) contamination of the oil by foreign matter. Oil is not worn out by friction but is destroyed by burning or decomposition caused by exposure to the intense heat of fuel combustion in the cylinders or the metallic parts of the combustion-chamber. The quantity so destroyed depends upon (a) fuel-combustion temperatures, (b) temperatures of the metallic parts, (c) quantity of oil exposed to these temperatures, (d) length of time of such exposure, and (e) volatility of the oil.
1925-01-01
Technical Paper
250035
C F Marvin
The usual laboratory tests of lubricants do not indicate to what degree a given oil may possess the important property of “oiliness,” a property, apparently independent of viscosity, upon which the ability of an oil to maintain lubrication between two surfaces under high pressure seems partly to depend and by which some sort of extremely tenacious and adherent thin layer of oil is held on one of or both the rubbing surfaces so that metal-to-metal contact is in part prevented. Oiliness is of special importance in metal-cutting operations and in some machine parts, such as gear teeth or cams under heavy loads, in which the pressures between the surfaces are far in excess of those permitted in plain bearings. With a view to investigating the behavior of various lubricants, cutting compounds and bearing materials under high bearing-pressures, a special machine has been designed, of which a description is given and data are presented.
1925-01-01
Technical Paper
250030
FRANK JARDINE
Corrosion in gasoline engines is generally believed to be due to sulphuric acid formed by the combination of sulphur carried in low-grade fuels and oils with water that enters or is generated in the engine. Much of this trouble occurs in winter and may be traced directly to the action of water that condenses on the inside of the cylinders and crankcase when a cold engine is started. The water destroys the oil-film and comes into direct contact with metal of the pistons, cylinders and other parts, causing them to rust. If this occurs and the lubricating system does not supply more oil to the surfaces immediately upon the restarting of the engine, scored cylinders and pistons are likely to result, or, if the engine is stopped before it is warmed up, condensation and rusting will be rapid and will result in excessive wear.
1925-01-01
Technical Paper
250031
M A THORNE
There is almost unanimous agreement that water in the crankcase is responsible for corrosion in internal-combustion engines. The quantity of water present in the products of combustion of the fuel is dependent upon the hydrogen content of the fuel, the mixture-ratio and the humidity of the air that enters the engine. The amount of water that may be condensed on the cylinder-walls or in the crankcase depends upon the effectiveness of the pistons and piston-rings in preventing gas leakage, the temperature of the cylinder-walls and crankcase and the extent of the breather action. The relative freedom of some engines from water accumulation is due to their higher operating-temperatures or to the better interchange of air by breather action which results in dilution of the gases in the crankcase and consequent reduction of the saturation temperature of the gases. Water alone will cause corrosion but the action may be accelerated by the formation of weak sulphurous or sulphuric acid.
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
250029
A H DENISON
Inasmuch as the heat or power developed by any fuel or combustible compound depends on the rate of flame propagation through the mixture, to increase the power and efficiency of present types of internal-combustion engine, the rate of flame propagation must be increased. Improvements in production engines to date have resulted primarily from modifications of the engine. Although the burning characteristics of conventional and low-priced fuels have received attention, nothing, with the exception of the heating of the hot-spot, has changed the conditions of the delivering and mixing of the charge during the last 20 years.
1925-01-01
Technical Paper
250026
F A MOSS, H H ALLEN
Although many variables enter into the personal equation of the driver of an automobile, this paper concerns principally his reaction-time. The tests described had for their objects the determining of (a) the average time that elapses between the hearing of a signal, such, for example, as the shot of a pistol, and the applying of the brake; (b) the relation between the reaction-time and the variability of the individual; and (c) the effect on reaction-time of such factors as the speed of driving, training, age, sex, race, and general intelligence. The reaction-time was determined by two pistols mounted on the under-side of the running-board of an automobile and pointed toward the ground, the first being fired by the experimenter when the car had reached the desired speed, the second, by the person under test in making the initial motion of operating the brake-pedal.
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
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
250025
J E MILLS
Successful operation of a general service-station depends upon the application of several business fundamentals. The service division of a car sales organization can be made to produce a fair profit by following proper methods, but the importance of the service division as a possible asset or liability has only recently begun to be recognized by the more progressive sales companies; surprisingly few service-station operators or managers have attempted to study the condition and to correct faults and increase the efficiency of their shops, while fewer still have any definite control-records for their guidance. Too many organizations try to conduct their service divisions with little or no attempt to follow the business principles that are observed by the foremost corporations in many lines of industry, with the inevitable result that the monthly balance sheets of the service-stations vary from a heavy loss to a fortunate profit.
1925-01-01
Technical Paper
250068
THOMAS H FROST, WALTER E RICHARDS
Principal stresses in one type of eye-bolt have been determined in the laboratory of photoelasticity at the Massachusetts Institute of Technology by the photoelastic method. In the test, an eye-bolt, designed in accordance with a method suggested for circular eyes in a course in machine design by the Institute, was made of celluloid 0.25 in. thick, 1 in. wide on either side of the eye, with a 1.405-in. diameter of eye, and a 1.333-in. width of shank. Steel loading-plates were pinned to the broadened end of the shank and a load of 100 lb. was suspended from the bolt, which gave a mean stress of 300 lb. per sq. in. in the shank. Plain polarized light was passed through the celluloid model and the isoclinic lines, or lines of equal inclination of principal stress, were observed and recorded. Two families of lines of principal stress, designated as P and Q stresses, were determined graphically from these isoclinic lines.
1925-01-01
Technical Paper
250069
J J FEELY
Following a description of airplane structure, the author discusses structural requirements and outlines the main features of properly coordinating the engineering and the manufacturing activities. He says that each of the three subdivisions of airplane design has its own series of calculations, these being related to predictions of performance before the machine is built, to stability determinations and to the design of a self-contained structure of sufficient strength to withstand any stresses developed in flight or in landing. He states also that no inspection is worth the name or the money spent on it that does not include constructive work and a knowledge at all times that the intentions of the designers are being carried out in detail so that the safety of the craft is assured. Materials used in aircraft should be light and easily workable and should possess the desired physical and chemical properties; they must have the specified cross-section and be free from defects.