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Viewing 19861 to 19890 of 19997
1929-01-01
Technical Paper
290004
W. B. BARNES
IN THIS paper, W. B. Barnes describes a device developed to give a graphical record of front-axle movements while the car is on the road. An analysis of these results reveals some startling facts concerning the amplitude and character of axle vibrations in various cars. When striking an obstruction or during brake application the axle as a whole may rotate forward as much as 5 deg., giving a negative value to the caster angle, which Mr. Barnes declares is utterly ruinous to any steering control. Furthermore, the instantaneous center of rotation may vary from a point near the level of the spring main-leaf to a point 4 or 5 in. above it. This paper was presented at the Chassis Conference at the Semi-Annual Meeting last June. The author supplements it with an explanation of the way in which certain of the principles developed in this research have been embodied in the design of the front-drive car announced by his organization since the presentation of the paper.
1929-01-01
Technical Paper
290009
ALEX TAUB
SIX CYLINDERS are used in the Chevrolet engine, because six cylinders give smoother action and a longer range of satisfactory performance than four. Maximum results per dollar has been the ideal in the design, and high output has been secured at a cost very little higher than for a four-cylinder engine. The piston displacement is large enough to give satisfactory performance without fine tuning. The bore is made as large as possible within the space required for water-cooling around the valves. The stroke is short, resulting in low inertia forces and a stiff crankshaft with the minimum amount of metal. Three main bearings are found sufficient, because of the stiffness of the shaft and the inherent balance of the groups of three cylinders. Positive lubrication is provided, without pressure. The overhead-valve mechanism is so proportioned and the cooling of the parts is so arranged that variations in expansion cancel each other and result in nearly constant valve clearance.
1929-01-01
Technical Paper
290011
T. J. LÍTLE
DEMAND for increased car-performance forces manufacturers to provide more powerful engines. It is desirable to obtain the increased power without designing a new engine, particularly in the case of large-scale manufacturers. The author lists possible means of doing this as making increases in the speed, the volumetric efficiency, the compression ratio, the thermal efficiency and the mechanical efficiency; and explores each of these methods in the light of latest developments in engine design. Among the concrete suggestions are greatly increased valve-lift, hydraulic valve-gears, multiple car-bureters, injection of vaporized fuel into cold air, cutting out the fan at high speed, and the use of superchargers. Higher compression generally involves changes in cylinder-head design, which are covered in some detail. Subjects covered in the discussion include lubrication, roller-chain camshaft drives, form of combustion-chamber, availability of engine power, and two-cycle engines.
1929-01-01
Technical Paper
290068
EDWARD P. WARNER
POINTING out that the fundamental object of securing speed, economy, safety and comfort is the same irrespective of the form of transportation used, the author emphasizes the necessity of establishing a balance among these more or less conflicting desirable factors of performance and determining just what that performance may be. The specific basic assumptions upon which the calculations of the paper are made are stated as being that an airplane cruises at 85 per cent of its maximum speed; that two-thirds of the maximum rated horsepower is consumed in level cruising-flight; fuel for a 400-mile flight is carried; the total weight of the powerplant is 2.5 lb. per hp.; weight of the airplane structure is 33 per cent of the total weight carried; and the pay-load is assumed to be two-thirds of the figure remaining after subtracting the structure, the powerplant, and the fuel weight.
1929-01-01
Technical Paper
290089
CARROLL C. HUMBER
METHODS of operation and maintenance pertaining to a small fleet of motorcoaches are described by the author, who outlines the development of this transportation service from July, 1922, when operation was begun. An inspection system was inaugurated in which due consideration was given to the type of equipment, the nature of the service performed, average loads, the speed maintained, and the nature of the roadway over which the vehicles traveled. In this manner preventive-maintenance methods were put into effect, the results being a steady increase in efficiency. In the author's opinion, itemized costs must be kept for each unit of the fleet so that the data will be available for the month, the year to date, the last full year and, if possible, for the last several years. The figures should be embodied in a statement so that comparison can be made between similar items for each unit operated. Units differing in make or type should be grouped and averages shown for each group.
1929-01-01
Technical Paper
290088
ADRIAN HUGHES
THE SATISFACTORY maintenance of motorcoaches probably has been the subject of more extensive discussion and study than has any other phase of fleet operation, in the author's opinion. Effective economical maintenance has a large influence on net profit, but the maintenance of motorcoaches is merely one phase of operation and, while it influences the other phases, it likewise is influenced by them. Cooperation is the most important factor contributing to successful maintenance, but the author remarks the difficulty of segregating any part of the organization which can be considered solely responsible. He asks where the maintenance organization begins and where it ends, and answers that it seems necessary to include the office, operating, garage and shop divisions and even the selling division. Each division must know something of the work of the other divisions and how its work fits in with that of the general organization.
1929-01-01
Technical Paper
290081
W. F. BANKS
MANY FACTORS gradually forced a recognition of motor-vehicles as necessary adjuncts to business, and now the motor-vehicle is being called upon more than ever before to serve also as a labor-saving device. The author believes that present-day business will demand further development of this nature. The groups interested in establishing and developing the motor-vehicle in business are the manufacturers thereof, the commercial organizations operating vehicles for their individual needs, the commercial operators supplying service for a variety of customers, and the railroads. The author pays tribute to the manufacturers for the present dependability of motor-vehicles and comments upon the extension of motor-vehicle service in the respective fields of the three other groups. Present competition in all forms of business makes the problem of cost accounting equally serious for all users of commercial vehicles, in the author's opinion.
1929-01-01
Technical Paper
290082
F. K. GLYNN
THE TECHNICAL requirements of motor-vehicle-fleet operation are receiving increasing attention, according to the author, who analyzes two distinctly different plans for fleet organization; one, that of providing for sufficient man-power to care for all repairs, and the other, of later origin and requiring a much smaller organization, the delegation of all repairs to the specialists of the commercial repair-shops. In analyzing these plans he considers a fleet of 500 vehicles. His analysis of the latter plan has to do with a fleet organization having no shop personnel and a total of 10 or more vehicles per employe, the fundamental requirements in this case being the provision of qualified inspector-repairmen and efficient manufacturers' and commercial service-stations.
1929-01-01
Technical Paper
290079
FREDERICK C. HORNER
AFTER defining the function of transport as the transfer of persons and things from one part of the earth's surface to another in the minimum time and at the minimum cost, and dividing modern transport into human, animal and mechanical, the author proceeds to describe the part played by commercial motor-vehicles in the Country's economic structure. Since food and drink are necessities of life, the first examples of motor-truck transportation discussed include the haulage of milk, bakery products, livestock, produce, vegetables and fruit. These are followed by the use of the motor-truck in local and long-distance general hauling, retail delivery service of dry-goods and chain-store supplies, the oil industry and for the transportation of express matter. A section follows on the use made of this form of transportation by public utilities and municipalities.
1929-01-01
Technical Paper
290080
R. A. C. HENRY
AFTER defining the meaning of store-door delivery and outlining its history in Canada, the author reviews in detail the functions of the cartage agent and the railroad company under that system, and gives an idea of the territory and population served. Operation of Canadian store-door delivery is fully described, both as to the terminal facilities and the methods of handling, recording and checking outbound and inbound freight shipments. The author shows that in eastern Canada more than 97 per cent of the carted inbound tonnage is delivered to consignees by the end of the day following its receipt at the railroad sheds. Cartage tariffs used in Canadian store-door delivery are given and the legal situation involved in the operation of cartage service by railroads is outlined.
1929-01-01
Technical Paper
290077
C. FAYETTE TAYLOR
SUPPLEMENTING the results of an investigation at the Massachusetts Institute of Technology on supercharging a single-cylinder automobile engine which were presented at the 1928 Annual Meeting, this paper reports a study that was made to determine whether the mechanical action of a high-speed centrifugal supercharger improves engine performance by increasing the degree of atomization and vaporization of the fuel in the inlet manifold. While changes in the degree of fuel atomization and vaporization might be measured directly by sampling the gases as they pass to each cylinder, an indirect evaluation of these changes by measuring their effect on engine performance was considered more practicable. Tests were made on a six-cylinder automobile engine connected to an electric cradle-dynamometer.
1928-01-01
Technical Paper
280053
A. MOORHOUSE, W. R. GRISWOLD
BECAUSE of the increased engine-speed and the limitations of progress by the previous method of designing valve-springs, Packard engineers entered upon fundamental studies of valve-spring behavior and of the influence of stress range upon durability. Various theories of the dynamics of valve-spring surge were investigated, and one was found which seems to agree fairly well with the observed phenomena. Jumping of valve push-rods and spring failures that could not be explained by the static analysis of spring design are accounted for by the dynamic analysis, which serves as an improved basis for design. Finding it impossible to design a single spring to meet the conditions, within the space limitations, a double spring with interlaced coils was designed. Descriptions are given of the provision for mounting the ends of the springs and the methods of assembly and inspection.
1928-01-01
Technical Paper
280065
E. E. WILSON
Abstract THREE basic ways in which naval aviation can assist the battle fleet to attain victory are stated, and the aircraft are classified as fighting, observation, torpedo and bombing, and patrol planes. The primary and secondary uses of the types are set forth, and, since their tactical employment controls the features of their design, a brief sketch is given of the tactical considerations of fleet air-work. The development of naval aircraft to date and the trend of future development are then described. As naval fighting planes must be carried on the ships of the fleet and must have the utmost possible performance and service ceiling compatible with low landing-speed, their size and weight have been reduced by the use of air-cooled radial engines and the intelligent employment of light alloys and ingenious detailed construction. The latest development in this class is a single-seater designed around the Wasp 500-hp. engine and equipped with a supercharger.
1928-01-01
Technical Paper
280041
DAVID GREGG
A STUDY of the effect of supercharging on the performance of the engines of passenger-cars showed that the power increase varied from 35 per cent at 1000 r.p.m. to 59 per cent at 3000 r.p.m., with a maximum supercharging pressure of only 6.5 lb. per sq. in. In acceleration tests made at the General Motors Proving Ground of two cars of similar model, one equipped with a supercharged engine and the other with a high-compression engine, the supercharged car accelerated from 5 to 25 m.p.h. in 5 sec.; the unsupercharged car, in 10 sec. From 15 to 50 m.p.h. the supercharged car accelerated in 12.7 sec.; the unsupercharged car, in 21.0 sec. On an 11-per cent grade up which the cars were started at 10 m.p.h., the speed of the supercharged car was 40 m.p.h. at the top; that of the unsupercharged car was 18 m.p.h. These and other results of the tests are portrayed by curves.
1928-01-01
Technical Paper
280038
D. SENSAUD DELAVAUD
Abstract MENTIONING the various attempts that have been made to secure continuous progressive changes of gear in the automobile, the author states that nothing of this sort is of value unless it is automatic. He has designed a transmission consisting of a wabble-plate which actuates six connecting-rods that operate as many roller clutches on the rear axle. Changes in speed result from varying the inclination of the wabble-plate, and this is controlled automatically through the combined effects of inertia and the reaction of resistance. This transmission has been applied to a number of cars of different weights, some of which have seen much service. The action of the various elements of the transmission is analyzed with the aid of drawings, diagrams and formulas, and the proportions that have been found most successful are stated. This transmission is combined with a gearless differential and a planetary reverse-gear.
1928-01-01
Technical Paper
280034
R. E. PLIMPTON
TO solve fleet-operation problems successfully, a professional consciousness is needed among the supervisors and the engineers engaged in the operating field, awakened by analyzing and making known generally the methods and practices used by the operators of individual fleets of motor-vehicles, according to the author. In developing his subject he asks the following questions and comments upon them: Has the operator any influence on design? Is that influence good or not? Whatever the influence is, can it be improved and made more effective? If it can be made more effective, how can this be done? If it cannot be made more effective, what is the reason? Regardless of variations in duties and of conditions in organization, each large-scale operator is vitally concerned with matters of design and construction.
1928-01-01
Technical Paper
280033
WALTER C. SANDERS
1928-01-01
Technical Paper
280032
H. F. FRITCH
1928-01-01
Technical Paper
280011
C. Fayette Taylor, L. Morgan Porter
1928-01-01
Technical Paper
280003
W. S. JAMES
AN attempt is made to show in their relative importance the more important of the major factors affecting car performance. The items dependent upon engine design that are considered are acceleration, hill-climbing ability, fuel consumption and maximum speed. The factors entering into engine and car design that are discussed are the size and speed of the engine, the compression ratio and the weight of the car. Experimental data have been used only in establishing reasonable engine and car characteristics. The effects of the changes desired were estimated on what are believed to be generally accepted bases.
1927-01-01
Technical Paper
270040
CHARLES FROESCH
THE engineering factors involved in the adaptation of the electric drive as applied to the motorcoach are presented by the author, who also enumerates the limitations of design. To raise the power curve at the higher engine-speeds and within the most efficient speed-range of the engine, which corresponds generally with a piston speed of from 1200 to 1600 ft. per min., without unduly sacrificing engine torque at the lower speed, the valve-timing must be changed. The author illustrates what effect this has by presenting data obtained with a four-cylinder engine of 4¼-in. bore and 5-in. stroke, together with other tabulated data and charts. With regard to the advantages and disadvantages of the electric drive, it has been fairly well established that the greatest asset, as applied to the motorcoach, is the permissible increase in scheduled speed where traffic is congested.
1927-01-01
Technical Paper
270027
C. C. CHAMPION
NAVAL aviation confined its activities to training and to coastal patrol during the World War. This limited operation was necessitated by the small amount of materiel suitable for operation over water, the strategical and geographical situation which determined the nature of the naval operations, the very limited performance of seaplanes of that period, and the fact that warships were not equipped for handling aircraft or prepared for aircraft cooperation. At the end of the War, naval aviation was made part and parcel of the fleet. Fighting airplanes are required to gain and maintain control of the air. Observation airplanes are used for short-range scouting and also for controlling long-range fire of capital ships by reporting the fall of shot to the ship by radio. For torpedo and bombing work, the first requirement is large weight-carrying capacity.
1927-01-01
Technical Paper
270071
C. M. KEYS
1927-01-01
Technical Paper
270070
A. H. G. FOKKER
1926-01-01
Technical Paper
260061
E. T. JONES
Confining his subject matter strictly to a discussion of the Wright Whirlwind engine and its bearing on the present status of the air-cooled aircraft-engine, the author says that the type of engine specified embodies in its development two distinct forms of cylinder construction, the first having been developed by Charles L. Lawrance and the second by S. D. Heron. The application of these cylinders to the engine under discussion is outlined and the subsequent development is traced. The development of the J-5 type of engine was undertaken in an effort to place the air-cooled engine fully on a par with the water-cooled type as regards fuel consumption. The cylinder is characterized by a hemispherical combustion-chamber employing two valves with axes inclined at 70 deg. The valve-seats are of aluminum-bronze shrunk into the cast-aluminum head. The cylinder-barrel with integral cooling-fins and hold-down flange is screwed and shrunk into the aluminum-head casting.
1926-01-01
Technical Paper
260060
E. E. WILSON
The purpose of the paper is to point out the basic policies which have resulted in the fostering of air-cooled-engine development by the Navy, and to indicate where the development has led. Two roles played by naval aviation are designated “air service” and “air force.” The former term refers to the functions of naval aircraft which are contributory to the ships of the fleets, such as scouting and the control of gun-fire. The latter term refers to the functions which involve the use of aircraft as an integral and component part of the Navy's striking force, such as combat, bombing and torpedo launching. Seven different types of aircraft are required by the Navy for its different purposes, these being airplanes for training, fighting, observation, scouting, torpedoing, bombing, and patrol use.
1926-01-01
Technical Paper
260013
C W ISELER
Progress has been made steadily in the application of superchargers to racing automobiles, and the author of the following paper has no doubt that the supercharger will be adopted as standard equipment on passenger automobiles of the better class within the next few years. Builders of the Mercedes car have placed on the market two models regularly equipped with a supercharger of the Roots blower type, and the increased power, flexibility and speed of these cars have shown the public the great possibilities obtainable by the supercharger. In addition to the foregoing advantages, the supercharger gives greater mechanical efficiency and fuel economy.
1926-01-01
Technical Paper
260045
F. C. Mock
This is an analysis of spring action such as occurs on an automobile driven on a highway having bumps and depressions, a discussion of the requirements of spring-recoil checking devices, and an account of experiments made with a car on which different combinations of springs of various lengths and flexibilities were used and the distribution of weight on the frame was varied. Spring action was analyzed previously by means of small models that simulated the suspension and weight distribution of a motor-car. The compression and recoil action of springs and their relation to the travel of the car as represented by the time element are discussed. Although the more-flexible springs absorb the bumps better, it is shown that their recoil is greater unless it is damped by a shock-absorbing device.
1926-01-01
Technical Paper
260018
F R FAGEOL
The problem in building the first “safety coach” was to short-cut evolution-to bridge the gap between what the industry had and what it needed. It is the purpose in this paper to consider the broad fundamentals and underlying principles of the Fageol safety-coach which have formed the basis of subsequent modern motorcoach construction, giving particulars of detailed design only to point out and illustrate the methods of definitely meeting the known needs. It was noted that equipment for all types of transportation had undergone a definite evolution, beginning with vehicles designed primarily for some other type of service. The early railroad equipment was adapted from the horse-drawn stagecoach. The first automobiles were literally “horseless carriages.” The first motor-stages were adapted from the touring car or the truck. Either of the latter was good for the purpose it was designed to fulfill-both had great shortcomings in public motor passenger-service.
1925-01-01
Technical Paper
250018
J W White
Inasmuch as the use of low-pressure tires has become established, the conditions of car design affected by them are reviewed, particular reference being had to the members of the chassis included under the term unsprung weight, namely, the axles, the wheels and the tires. Referring to the principles that underlie basic design, the author first investigates the effect on the steering of such changes and compromises from the perfect structure as failure of the king-pin to coincide with the vertical load-plane, the inclination of the king-pin toward the wheel, or the wheel toward the king-pin, or both, and the giving of a toe-in to the front wheels. Further modifications have served to reduce the car shock, to add to the strength of all the parts by increasing the dimensions, to improve the spring-suspension, and to reduce the car weight per passenger.
Viewing 19861 to 19890 of 19997