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Viewing 15271 to 15300 of 15355
1929-01-01
Technical Paper
290001
MERRITT L. FOX, THOMAS J. CARMICHAEL
This paper describes the construction, theory and some uses of the Gyro-Accelerometer, an instrument capable of recording angular velocity, angular acceleration and the total angle turned. The design and development of this instrument came as the result of research into the riding-qualities of automobiles conducted by the Department of Mechanical Engineering at the State University of Iowa. These investigations demonstrated the necessity of measuring angular motions under road conditions which was impossible with available equipment. The instrument furnishes an analysis of angular movements whereby the characteristics of the springs and shock-absorbers can be so matched as to give the body the lowest values of angular acceleration and therefore the best riding-quality.
1929-01-01
Technical Paper
290087
LEONARD ROSE
HEREIN the author points out, as a preface to a description of the preventive-maintenance system which he describes, that any system of maintenance is only as good as the men behind it and the honesty with which they use it. The personnel must be convinced that if the system is followed it will help the men to better themselves by pointing out their mistakes. The workers must be made to realize that the thing which really counts is not so much who made the mistake but what the mistake was and why it was made. Daily, weekly and general inspections are practised in accordance with this preventive-maintenance policy, and details of the procedure with regard to records are given by the author. The company's repair and overhaul program is designed to eliminate guesswork to the greatest possible extent by providing instruments and standard testing-apparatus for determining the actual condition of the various motorcoach units both before and after repairs are made.
1929-01-01
Technical Paper
290036
V. VOORHEES, JOHN O. EISINGER
THIS PAPER is divided in two parts. The first part is devoted to engine tests made on gasolines having different gum contents. The tests made indicate the quantity of gum that can be tolerated in a motor fuel before it will noticeably affect engine operation. It was found that only the actually dissolved or preformed gum in a gasoline at the time of use directly affects engine operation. The gum usually collects on the hot parts of the intake system, particularly the inlet valve. Photographs showing the condition of the inlet valve and cylinder-head of the test engine are reproduced. Also, in the first part, the gum-forming tendency of fuels that are stored for some time prior to use is discussed. The second part of the paper, consisting of the appendix, takes up the causes and methods of testing gasoline for gum.
1929-01-01
Technical Paper
290033
ARTHUR W. GARDINER
SO-CALLED correction factors to compensate for variations in atmospheric temperature and pressure have been in practical use in connection with engine testing; but the influence of the varying amount of aqueous vapor present in the atmosphere has not had sufficient consideration. The author submits brief test-data indicative of the effect of humidity on some factors of engine performance and of the feasibility of using rational power-correction factors. By assigning due importance to the effect of humidity, he believes that a more satisfactory analysis of car and of engine performance can be obtained. Using a single-cylinder engine operated at full throttle and 1000 r.p.m. under stabilized conditions, tests were made observing maximum power, air-flow, fuel-flow, detonation and spark-advance requirements over a wide range of relative humidity for an air-intake temperature of 100 deg. fahr. Curves made from the data obtained are given and discussed.
1928-01-01
Technical Paper
280058
BIRGER EGEBERG
AFTER outlining the progress of research in the development of the alloy steels, the author says that alloys of steel containing nickel, chromium, and nickel and chromium, are the most important to the automotive industry, which is especially interested in alloys containing up to 5.0 per cent of nickel and up to approximately 1.5 per cent of chromium, with the carbon content ranging from 0.10 to 0.50 per cent. The additions of these amounts do not materially change the nature of the metallographic constituents, but the elements exert their influence on the physical properties largely by altering the rate of the structural changes. In straight carbon-steel, especially of large sections, it is not possible by quenching to retard the austenite transformation sufficiently to produce as good physical properties as are desired.
1928-01-01
Technical Paper
280062
CHARLES H. LOGUE, R. B. FEHR
BY means of the gear-correcting process described, spur and helical gears are corrected to give a high degree of uniformity in spacing and profile so that the gears become practically interchangeable. They acquire a “crown face” which enables them to run with unusual quietness under practical conditions. This is essentially an inspection-correction process, as it automatically finds and eliminates the errors. The lap is the important item in the process. It is of chilled cast-iron, gray cast-iron, or type metal, and is made by casting in a mold around a steel chill cut to approximate the gear to be corrected but has a face-width several times that of the gear. The lap, when completed, looks like a wide-faced internal gear.
1928-01-01
Technical Paper
280043
DONALD B. BROOKS
SELECTION of a method and development of apparatus enabling precise and detailed measurement of engine acceleration is discussed in the first portion of this paper, the latter portion of which is concerned with the experimental results thereby obtained. Previous work on the influence of engine conditions on acceleration is generally substantiated. A method is described for approximately deriving the effective air-fuel ratio delivered to the cylinders during acceleration, practical applications are suggested, and limitations are discussed. The effect of fuel volatility on engine acceleration was studied, using six fuels: Aviation gasoline; commercial gasoline; a blend composed of equal parts of the two; and three especially prepared fuels, all of which have equal 20 and 90-per cent points but differ widely at the 50-per cent point. It is shown that the relative values of these fuels for acceleration depend upon the amount of vaporization in the manifold.
1928-01-01
Technical Paper
280005
OSCAR C. BRIDGEMAN
FIRST referring to previous reports made on laboratory methods for measurement of volatility, the author states that data for a variety of gasolines, obtained by the equilibrium air-distillation method, have been analyzed recently in comparison with the distillation curves of these fuels as determined by the procedure practised by the American Society for Testing Materials. According to the author, this analysis appears to indicate a definite relationship between the results on volatility and those obtained by the standard A.S.T.M. distillation method, so that it seems possible to deduce from the latter with reasonable accuracy the information on volatility which is pertinent to satisfactory engine performance. It is stated also that volatility can be regarded as the tendency to escape into the vapor or gaseous state and this escaping tendency is determined by factors which must be precisely specified so that numerical values for volatility may have significance.
1928-01-01
Technical Paper
280008
GRAHAM EDGAR
NINE laboratories employing widely different methods have cooperated in the measurement of the knock characteristics of five selected motor fuels. Considerable divergencies are reported in the results obtained by different methods, particularly for certain fuels, although there is reasonable agreement for other fuels. Laboratories using the “bouncing-pin” method have shown consistent results among themselves. No system of rating the knock characteristics of fuels is in use at present by which the results of different laboratories are readily comparable. An analysis of the data obtained from the nine laboratories is included herein, and possible reasons for the divergencies are discussed. First reviewing the circumstances that led to the investigation reported in his paper, the author names the laboratories which cooperated, describes the sample fuels and how they were prepared, and outlines the method or methods practised by each laboratory and the equipment used.
1928-01-01
Technical Paper
280071
CHARLES F. SMITH
PROPER brake testing is stated to involve the measuring and recording of vehicle deceleration and rate of speed for every foot of individual wheel travel during the period from the initial application of the brakes up to the moment the car comes to a standstill. The brake synchrometer, designed to duplicate the conditions under which a vehicle is tested on the road, embodies the principle of traction between each tire of the vehicle, on one hand, and a rotor on the other hand. The kinetic enegery of the four testing rotors must be equal to the energy of a vehicle of a certain weight at a given testing speed. The author describes a brake synchrometer designed for testing vehicles of 3500-lb. weight, which machine, however, is adjustable to compensate for greater or lesser car weight, so as to include heavier or lighter vehicles in its test range.
1927-01-01
Technical Paper
270005
SAMUEL P. MARLEY, DONALD R. STEVENS, W. A. GRUSE
AN examination for detonating qualities of 18 petroleum gasolines was made by the authors, the methods used being those of direct engine-tests and of chemical analysis. A single-cylinder lighting-plant engine, suitably modified, and a direct-reading detonation-indicator were utilized and they are described. The method of Morrell and Egloff was followed in the chemical analysis. This consists in determining the proportions of paraffins, naphthenes, unsaturated and aromatic hydrocarbons and calculating the aromatic equivalence of the hydrocarbons so found by the use of data compiled by Ricardo on the relative knock-reducing tendency of unsaturated hydrocarbons, naphthenes and aromatic hydrocarbons. These data indicate an equivalence expressed by the ratio 5 to 4 to 1. Experiments were made in which a constant proportion of one hydrocarbon of each class was added to a gasoline, and the detonating tendency of the resulting mixture was determined by engine test.
1927-01-01
Technical Paper
270004
W. F. FARAGHER, W. H. HUBNER
AS the title indicates, this paper comprises a description of the construction of an apparatus and the development of a method of operating it in determining the rating of motor fuels in the order of their detonation. A Delco-light unit, consisting of a single-cylinder internal-combustion engine directly connected to a direct-current generator, was the basic outfit used but it was changed in many ways in its course of development as a testing-machine. The changes made are explained in detail. The method of testing adopted for rating a motor fuel was to match it, by trial and error, with a blend of chemically pure benzene and selected straight-run Pennsylvania gasoline. Several series of experiments were made to determine what blend or blends of benzene and the standard gasoline match a given fuel under widely different conditions of compression-ratio and spark-setting.
1927-01-01
Technical Paper
270011
George L. Clark, Robert H. Aborn, Elmer W. Brugmann
ABSTRACT
1927-01-01
Technical Paper
270003
H. K. CUMMINGS
THIS paper was prepared as part of the Cooperative Fuel Research program and presents mainly a review of published data on methods of measuring the anti-detonating qualities of motor fuels. Although detonation as a factor in gaseous explosive reactions is not a new subject, the general recognition of anti-knock value as an important quality of automotive engine-fuels is comparatively recent. Reference is made to bibliographies covering earlier work in this field, and an outline is given of work now in progress at various laboratories and universities. Ricardo's two test-engines and his methods of rating fuels in terms of highest useful compression-ratio and toluene value are described, and the applicability of his results to other engines is discussed. The British Air Ministry Laboratory, using a Ricardo variable-compression engine, compares fuels on the basis of percentage of increase in highest useful compression-ratio.
1927-01-01
Technical Paper
270037
H. H. LESTER
TESTS of metals with X-rays, as made at Watertown Arsenal, are of two classes: (a) radiographic tests in which photographic images of internal details of the gross structure are obtained and (b) diffraction tests in which images are obtained that may be interpreted to give information regarding details of micro-structure of the constituents in the metal. The present paper deals with tests in the first class. Diffraction tests will eventually result in steels that have better physical properties required for special applications in industry, but such improvement must be accompanied by elimination of defects in the gross structure of forgings and castings before the greatest utility of better steels can be realized. Radiographic testing gives pictures of defects whereby the nature of the defects can be determined, but their causes must be sought by logical deductions from other information.
1927-01-01
Technical Paper
270047
S. VON AMMON
A REPORT on the investigation of brake-lining materials by the Bureau of Standards was made by the author in 1922. The present paper gives information on work done in this field since that time. It places on record a summary and discussion of various test-methods and equipment at present employed by brake-lining manufacturers and others in the automotive industry. The difficulties connected with this work, resulting from the varying characteristics of brake-lining materials, are brought out. It is shown that some of the test methods in use do not furnish a basis for ready or fair comparison of different brake-linings. Other test procedures are so limited as to give only an incomplete picture of the characteristics of the brake-linings under conditions met in service; therefore, the test schedules generally require readjustment and amplification because a full and satisfactory knowledge of these materials can be obtained in this manner only.
1927-01-01
Technical Paper
270060
M. N. NICKOWITZ
MORE than 13,000,000 yd. of rubber-coated top-material was produced in this Country in 1926, and, in addition, approximately 6,000,000 yd. of other types of material, including pyroxylin and oil-coated fabrics, was used for automobile tops. Principal ingredients entering into the manufacture of rubber-coated top and deck material are base fabrics, crude and reclaimed rubber, naphtha, sulphur, accelerators, antioxidants, inert fillers, softeners, and varnishes. Methods of manufacture are much like those used in the production of cellulose-nitrate or pyroxylin-coated fabrics, and the types of fabric used and their preparation are similar. Processes of preparing the rubber compound, applying it to the fabric, varnishing the surface and embossing the material are described briefly.
1927-01-01
Technical Paper
270045
C. M. MANLY, B. LIEBOWITZ
THIS article reports research directed toward laboratory verification of deductions arrived at in Dr. Liebowitz's theoretical research.3 C. M. Manly, C. B. Veal4 and Dr. Liebowitz have been studying for some time the problem of devising an apparatus to test accelerometers. Mr. Manly and Dr. Liebowitz here summarize the results of the development work. The testing apparatus constructed incorporates an attempt to avoid the uncertain errors of any crank-motion by obtaining harmonic motion through the rotation of eccentric weights mounted on a spring-board, thus obtaining the advantage of extreme simplicity, minimum cost and at the same time avoiding the errors incident to lost motion by employing a molecular hinge. Results of a short series of experimental runs with a micrometer type of accelerometer are given.
1926-01-01
Technical Paper
260057
A. H. FRAUENTHAL
Although production has been increased greatly during the last decade by the use of special automatic machinery, conveyors and improved methods, plans for the application of wage incentives to indirect labor have not been widely adopted. Inasmuch as time-studies of some sort of wage-incentive system have served to keep the individual output of direct labor close to its assignment, the assumption is made that the labor of the indirect workers might also be so measured to a standard that the compensation would be governed by the quantity and the quality of the ultimate output. The advantages and functions of inspection are discussed and a method is suggested for establishing a quality-bonus incentive-plan based on the amount of rejected and scrap material per car and the number of inspectors employed per unit of production.
1926-01-01
Technical Paper
260007
T E COLEMAN, J B FISHER
Always prominent in the thoughts of automotive engineers, the lubrication of an internal-combustion engine presents continuous interest in that characteristic and elusive lubrication difficulties exist which largely baffle correction. Many of these difficulties are still existent because, according to the authors, more energy has been expended in correcting diseases of the lubricating system than has been spent in preventing the diseases by original design. When analysis is made of what has been done in the last few years of study on lubrication, it is irksome to realize that we still have to contend with all the former troubles such as oil-pumping or over-lubrication, fuel dilution of the oil supply, lubrication failures under certain conditions of engine operation, excessive wear on engine parts, and high maintenance-costs.
1926-01-01
Technical Paper
260032
T. S. SLIGH
Elementary theories regarding the evaporation characteristics of pure substances and mixed liquids are discussed briefly and the difficulties likely to be encountered in attempts to calculate the volatilities of motor fuels from data relating to pure substances or in the extrapolation of volatility data corresponding to the atmospheric boiling-range of the fuel to the range of temperatures encountered in utilization of the fuel are pointed out. A brief review of previous methods of arriving at fuel volatility is also presented. Volatility, as applied to motor fuels, is defined as being measured by the percentage of a given quantity of the fuel which can be evaporated under equilibrium conditions into a specified volume. The weight of air under known pressures is taken as a convenient measure of the volume. The new method described is an equilibrium distillation of the fuel in the presence of a known weight of air.
1926-01-01
Technical Paper
260001
John O. Eisinger
ABSTRACT
1926-01-01
Technical Paper
260017
O T KREUSSER
Layout, facilities and activities relating to making road-tests of motor vehicles at the 1125-acre proving grounds of the General Motors Corporation near Detroit, this tract being designed to provide a place where road conditions are suitable for obtaining data that can be interpreted accurately, compared with similar data and used constructively, are outlined and illustrated. Adequate facilities are provided and ideal road-conditions have been established so that motor-vehicle tests involving endurance, speed, acceleration, hill climbing, riding-quality and other comparative tests can be made. Conditions are such that tests can be repeated from day to day, thus compensating for the variations of the weather and other factors. Complete and conclusive tests can be carried out readily and promptly, and the results are free from guesses and personal opinions. The speed track is 20 ft. wide and nearly 4 miles long. Traffic is in one direction, clockwise.
1926-01-01
Technical Paper
260038
FLOYD A. FIRESTONE
Research methods applied to the inspection of automotive parts for noise-producing causes are analyzed by the author, who notes the increasing tendency toward the use of sound-measuring instruments and discusses first the units of sound intensity and loudness. The dyne per square centimeter is a convenient size of unit for measuring the pressure amplitude of sound-waves, since 1 dyne per sq. cm. lies within the range of amplitudes at which the ear normally functions, being approximately that at one's ear when listening to conversation. In calibrating at high frequencies, the thermophone is used. It consists of a small strip of thin platinum or gold a few centimeters long and about 1 cm. wide through which an alternating current of desired frequency is sent.
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
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
250064
E F COLLINS
Will sheet steel that is to be used in the manufacture of automobile parts form the parts for which it is intended without breaking, buckling or pulling coarse at the sharp corners is a question, the answer to which is sought through a series of tests applied to samples of the material by the Packard Motor Car Co. Three sheets are selected from different parts of every 1000 sheets received. After sections have been removed from the ends of these sample sheets, four test pieces are taken from each sheet at specified locations and these last samples are subjected to Erichsen, Rockwell and tensile-strength tests, each of which is discussed.
1925-01-01
Technical Paper
250058
C J ROSS
With the passing of the apprenticeship system and the introduction of the present method of employing unskilled labor on a piecework basis for assembling, careful inspection has become a necessity. Under these conditions, the only way in which the product can be held to the required standards is to make the component parts fit accurately. If the inspection is adequate, parts can be held to closer limits and cheaper labor can be used in the assembling process. Believing that no reason can exist for failure to maintain standards of accuracy if the ratio of the number of men engaged in production to one inspector does not exceed 15 to 1, the officials of the Buick Company have worked out a system, similar in many respects to a budget, in which a certain ratio of production hours to inspection hours is allowed in each plant, the number depending upon the nature of the work and varying from about 10 to 1 in the engine plant to about 34 to 1 in the gray-iron foundry.
1925-01-01
Technical Paper
250020
E A De Waters
In the summer of 1922 the Buick Company began experimenting with balloon tires. The first tires tested, being four-ply and 32 x 6.20 in. in size, produced a galloping action that was sufficient to prejudice the company's engineers against them, and the tests were discontinued. In addition to the galloping effect, other difficulties encountered included those usually present in steering, the development of wheel shimmying to a serious degree, the lack of proper clearance for external brakes because of the small 20-in. wheels, the excessively rapid wear of the tire tread, and the greater susceptibility to puncture. Leaks because of the pinching of the inner tubes also occurred. When, later, a set of 5.25-in. tires was tried on a smaller car, the galloping was noticeably less; but punctures were more numerous than was the case with high-pressure tires.
1925-01-01
Technical Paper
250009
A H HOFFMAN
Rapid wearing out of the engines of farm tractors, trucks and automobiles led the University of California to undertake a study of the dust problem and the efficiency of air-cleaners in removing field and road dust from the air before it passes into the engine. Work was begun in 1922 and several reports have been made on the methods devised and the progress made during the last 2 years. Results to June, 1924, were given in the paper published in August, 1924. The present paper gives results of the studies to the end of 1924 and includes data from tests of 12 new makes or models of air-cleaner not previously tested or not fully tested. Of outstanding importance is the discovery that the quantity of dust inspired by any cleaner or carbureter is greatly reduced if the intake is placed high and faces away from the direction of motion of the vehicle.
Viewing 15271 to 15300 of 15355