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Viewing 188461 to 188490 of 189418
1924-01-01
Technical Paper
240045
HUGH G BERSIE
Classes of service already provided by the street-car and the passenger automobile influence the expectations of the motorbus passenger regarding the quality of transportation service afforded by the motorbus. If an operator persuades people to ride in his motorbuses, it will be because they offer safety, economy, convenience and comfort to a greater degree than that offered by competitive transportation media. Since the public has demonstrated that, under favorable conditions, it will patronize the motorbus to an extent that yields a profit to the operators, the future success of this means of transportation lies wholly within the control of the motorbus builders and those who operate it. Of the factors that determine the degree of success attained, motorbus-body design bulks very large. Discussion of the subject is presented from the viewpoint of the passenger, as the motorbus approaches him, as he enters it and as he judges the quality of transportation it affords.
1924-01-01
Technical Paper
240043
TOM W GREENE
In this investigation to determine strength and physical properties 12 motor-truck rear-wheels were tested, comprising two each of the following types: Class-B trucks, standard wood; Class-B truck, cast-steel; I-beam type; steel disc; aluminum; and rubber-cushion, each having a 34-in. diameter and a 12-in. tread. The wood, the I-beam and the cushion wheels each had 14 spokes; the aluminum and the steel-disc wheels had a solid web between the hub and the rim. All the wheels were tested without tires or brake-bands, were bushed to fit a 4-in. axle and the area of contact between the hub and the bushing was the same as that in service. Illustrations show the construction of the wheels. Requirements considered essential in a wheel were listed, and the tests were conducted to obtain data concerning them. One wheel of each type was subjected to a radial-compression test.
1924-01-01
Technical Paper
240042
WILLARD F ROCKWELL
Tendencies of the industry toward lower costs have been reflected in axle design. Large-volume business has made it worthwhile to introduce changes in the design of passenger-car and light-truck axles to increase production economy and improve design. For heavy trucks, the trend has been to keep costs down by making no changes that would involve added expense for tools, jigs, dies and fixtures. Front-wheel brakes for passenger cars have resulted in changing front-axle I-beam sections and front-spring design to take care of the increased stresses such brakes introduce. In the design of rear axles for passenger cars, no fundamental change has occurred, although the change from the full-floating and three-quarter floating types to the semi-floating axle and a change in mounting the bevel pinion are two features that seem to be coming to the fore.
1924-01-01
Technical Paper
240048
JAMES W CAIN
Referring to the McKeen gasoline-driven car and one of the gasoline-electric type that were introduced in the early part of the present century and were the pioneers among self-propelled cars for railroad use, the author ascribes their limited success to their excessive weight and to engine and transmission troubles. Both these types, he thinks, might have been developed successfully had the gasoline engine been in its present state of efficiency and reliability. The early attempts having been more or less unsuccessful, the construction of all types was discontinued during the war. More recently the progress in the design and construction of highway motor-trucks has caused them to be adapted to railroad service by applying flanged tires to the rear wheels, pivotal pony-trucks forward and a motorbus body for the carrying of passengers and a limited amount of baggage.
1924-01-01
Technical Paper
240049
W L BEAN
Gasoline rail-cars for branches of trunk-line railroads and for short-line roads have been the subject of much discussion since 1920. Mechanical officers of interested railroads, the engineers of companies building highway motor-trucks and others specializing on this subject have now developed designs to meet the different service requirements. Several hundred cars of various types have been built and are in service. The railroad with which the author is connected has in operation or on order 24 cars. Consideration of several principal factors of design is necessary if a selection is to result in obtaining equipment suitable for the particular service requirements of the carrier and if the knowledge accruing from the engineering development and operating experience of the past several years is to be of value.
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.
1924-01-01
Technical Paper
240046
A F MASURY
Substantial reduction of motorbus depreciation by materially increasing the useful life of the vehicle is an important problem now facing the automotive engineer. The author contrasts present motorbus life with that of street-cars; he finds a probable life of 4 or 5 years only for the former and 20 to 25 years for the average type of trolley-car. This, in the case of the motorbus, he says, is too short a period of usefulness and directly affects operating costs, since the increased cost of motorbus maintenance offsets its lower initial-cost. Demand for maximum comfort, safety and speed from the public and for economical operation from the operators has renewed interest in the six-wheel motorbus and given its design an impetus, although present four-wheel motorbuses of 25 to 30-passenger capacity have, and will continue to have, a very definite field and will not become obsolete due to replacement by other types.
1924-01-01
Technical Paper
240037
E H LOCKWOOD, L B KIMBALL
A portable instrument of the seismograph type has been designed for measuring the riding-quality of vehicles. Headings are made by a continuously revolving counter that automatically sums up the vertical displacements of a partly suspended weight. As the counter readings are a measure of the riding-quality, a large reading indicates poor riding and, conversely, a small reading indicates good riding. An arbitrary scale graduated into revolutions of the counter per mile of travel translates the readings into riding-quality; a reading of 10 indicates “very smooth,” 20, “good,” etc. The instruments have been calibrated in a special testing-machine in which the readings can be observed under an harmonic motion of fixed period and amplitude. Comparison of the riding-qualities of balloon tires and of cord tires, made on three different automobiles run over a variety of roads, shows results that are very favorable to balloon tires.
1924-01-01
Technical Paper
240036
JOHN A C WARNER
The ascertaining of the factors that determine the riding-qualities of automobiles and the methods employed in studying these factors and the lines along which research should be directed in an effort to improve riding conditions are proposed in this paper with a view to encouraging further helpful discussion of the riding-qualities problem. Relative to the first of these questions, the factors treated in this paper comprise (a) road characteristics with respect to the vehicle; (b) the vertical, the longitudinal and the transverse motions of an automobile, as well as small vibrations or oscillations of high frequency; (c) vehicle characteristics, such as springing, accessory control, tires, wheels, chassis frame, seating, body, engine and transmission, steering-gear, brakes, heating, ventilating and lighting.
1924-01-01
Technical Paper
240035
A B SQUYER
A good air-cleaner is an essential part of automotive engine equipment. Many types of cleaner are on the market and the user must choose on the basis of the three essential requirements of maximum cleaning efficiency, minimum attention from the operator and minimum power-loss. With respect to these three essentials, the development of a laboratory method of testing air-cleaners starts with the premise that the test for efficiency should consist of feeding in a weighed quantity of dust, and an account be made for that which is not separated by the cleaner. The first method was to insert a white outing-flannel cloth in the airstream from the cleaner. The varied degrees of soiling of the cloths from different cleaners were a relative measure of their efficiency. This method was found unsatisfactory for several reasons. An attempt was made to use a dry centrifugal cleaner of predetermined efficiency, in series with the cleaner under test, to catch a portion of the dust escaping.
1924-01-01
Technical Paper
240034
A H HOFFMAN
References are made to published results of similar tests of air-cleaner devices conducted in 1922, and the scope of the 1924 tests is described. Road tests of air-cleaners were carried out and the tabulated data are presented. Efforts were made to find out how much dust the engine would draw in if the cleaner and connections were removed and to catch and weigh the dust the air-cleaner under test failed to catch. Dust was raised by a car running about 50 ft. ahead of the test-car and, to produce heavy dust-conditions, the road was dragged with a chain attached to the car and forming a loop behind it. The leading drivers maintained as nearly as possible a constant speed of 25 m.p.h. and chose the dustiest part of the road, following the same course on all the rounds.
1924-01-01
Technical Paper
240041
R B DAY
Shimmying was noticeable before four-wheel brakes began to be used, but since that time the trouble has been greatly increased. Two kinds are distinguishable; (a) low-speed shimmying, a violent wabble of the front wheels about the king-pins without a bouncing of the front axle, and (b) high-speed shimmying, a severe bouncing of the front axle during which one hub is up while the other is down. This occurs at somewhat higher tire-pressures and at high car-speed. Believing that both forms are not correctible by changing the design of the tire and are only slightly affected by changes in the steering-gear, efforts were directed toward prevention rather than correction.
1924-01-01
Technical Paper
240040
J E HALE
Balloon tires have caused the points at which the greatest trouble formerly occurred to be reversed; the greatest wear hitherto has occurred on the rear tires; now it occurs on the front. The carcasses of old tires were heavy and thick and carried a large part of the load; balloon tires are flexible and will support very little load. The air-pressure carries the load and gives greater cushioning effect. Four-ply tires have proved to be the most satisfactory and have none of the disadvantages of high-pressure tires. Balloon tires steer harder than high-pressure tires because of lower air-pressure, which necessitates a greater area of contact. Steering resistance is caused by the load on the tire and the increased area of contact. Many designers, in making the steering gear free to overcome steering resistance, make wheel-twitching possible. Shimmying may be classified as low-speed and high-speed, the latter occurring at speeds between 35 and 40 m.p.h. and being very violent.
1924-01-01
Technical Paper
240039
JOHN J MCELROY
An air-spring and a steel-spring combination has a characteristic load-curve that allows maximum flexibility in the general working-range of the axle yet has an increasing resistance to dissipate large shock-loads. By varying the compression volume in the air-spring, the load curve of the combination can be made more flexible or stiffer as occasion demands. Tests show that the steel-spring vibration alone had a duration of 5½ sec. with a period of 87.2 vibrations per min.; the combination, a 3-sec. duration with 60.0 vibrations per min. Field tests of front-axle movement were made, the test apparatus for these and other tests being illustrated and explained. The maximum axle-movement either above or below the normal line is increased when using air-springs, and the subsequent rebound shows more action on the underside of the normal line, the general tendency of the air-springs being to float the chassis on a slightly higher plane at the time of rebound.
1924-01-01
Technical Paper
240038
S P HESS
Riding-comfort is defined as the transportation of an automobile passenger in so easy a manner that the trip will be a pleasure and not a hardship. Since spring-suspension constitutes the basis of riding comfort in passenger-cars, the paper deals with some of the important factors that determine correct chassis spring-suspension. An analysis made by the National Automobile Chamber of Commerce of replies received to a questionnaire it circulated among 20,000 car-owners is presented in proof of the genuine interest the motoring public has in the riding-quality of a car and the variable factors that have an influence on spring-suspension are stated to be the type of spring used, its physical dimensions, the amounts of sprung and unsprung weight, frame construction, wheelbase dimension and the kind of material used. Horizontal, vertical and sidewise motions of a car are analyzed, and a periodicity chart is shown for passenger cars of from 112 to 116-in. wheelbase.
1924-01-01
Technical Paper
240029
JOHN O EISINGER
This paper deals with progress in the Cooperative Fuel Research since the last report was presented to this Society. Previous tests had shown that the temperature of the jacket water exerted a major influence on the rate of dilution of crankcase oil. The reason for this influence was investigated and it was concluded that it was due to differences in the rate at which diluent was added to or eliminated from the oil-film upon the cylinder-walls, the temperature of this film being dependent upon the temperature of the jacket water. Experiments failed to show that changes in the temperature of the piston head or changes in the viscosity of the oil upon the cylinder-walls exerted a major influence upon the rate of dilution. These conditions were investigated as being probable consequences of a change in the temperature of the jacket water. Evidence is presented which demonstrates that under certain conditions the diluent may be eliminated from the oil at a fairly rapid rate.
1924-01-01
Technical Paper
240028
George J. Mead
ABSTRACT
1924-01-01
Technical Paper
240026
J F WINCHESTER
Solicitation of sales and the delivery of the product to the customer constitute the most important operative features of the motor-truck fleet supervised by the author. Endeavor is made to install the vehicles in the various fields along standardized lines. The volume and the extent of the business and the topographical conditions of each locality determine the size and the mechanical equipment of the vehicle that is employed, and it is installed only after a study of all the conditions pertaining to its operation. Adequate training of vehicle operators, not only along mechanical lines but also as direct sales representatives of the company, is made a feature; and so is accident prevention. These interests are promoted in various standard ways and are furthered by the publication of “house organs.” After a vehicle is installed the slogan adopted is: Keep It Moving With a Pay Load.
1924-01-01
Technical Paper
240027
R E PLIMPTON
Operating costs and their relation to the age of the vehicle have been a subject of controversy for some time. One faction maintains that after a certain indefinite period it is economy to salvage or junk the equipment and replace the vehicles with later uptodate designs. The opposing faction believes that the costs depending on maintenance and operating efficiency can be kept fairly constant. Comparing a motor truck with a locomotive they cite the opinion of railroad officials that when proper running repairs are made locomotives can be maintained continuously in the same service and retain their original earning capacity for many years. When new locomotives are built it is usually for the purpose of replacing types that have become obsolete and the old ones are then relegated to some other branch of the service.
1924-01-01
Technical Paper
240033
S D HERON
Trouble with the exhaust-valves of the Type-J air-cooled cylinder caused an investigation to be made of valve-cooling and of valve and guide wear. A temperature of 1300 deg. fahr. invariably caused fractures of the exhaust-valve stem at the junction of the stem and the neck. A file-hard tungsten-steel valve with a shallow hole and no filling eliminated breakage but scaling was apparent. The same valve, using a hard tungsten-steel guide, when tested with salt filling, gave improved cooling; the area of the hot zone was reduced in size and the stem remained dead-black. Scaling was reduced and the wear of the valve-stem and guide that appeared was overcome by substituting a roller tappet for the solid tappet previously used. Tests showed that extreme hardness is of advantage even for inlet-valves. Experiments with a Type-K air-cooled cylinder gave excellent results with a salt-cooled valve in spite of a very high head-temperature; with an unfilled valve the results were not so good.
1924-01-01
Technical Paper
240032
RALPH L SKINNER
It is generally recognized that the dilution of crankcase-oil with water and unburned fuel tends to accelerate the wear of engine bearings, cylinders and pistons. The author traces the engineering development of a rectifying device and system designed to combat this problem. In this system, diluted oil that tends to work-up past the pistons, in company with the water vapor and unburned fuel that tend to work down into the crankcase, is drawn from the cylinder-walls and pistons by vacuum. This diluted oil is conducted into a still or rectifier where it is subjected to heat from the engine exhaust. The heating action is just sufficient to volatilize the fuel and water, the resulting vapor being returned to the intake-manifold and thence to the engine where it is burned. The lubricating oil that remains behind is conducted back into the crankcase. The system functions automatically.
1924-01-01
Technical Paper
240030
NEIL MACCOULL
An independent study of a similar nature to that made by the Bureau of Standards on fuels in 1923 was conducted by the company the author represents, and the paper presents first the results of the tests made on five 7½-ton trucks during the regular course of business deliveries. Curves plotted from the data thus obtained are presented and analyzed in considerable detail. These data were then utilized as a basis for a series of dynamometer experiments in an attempt to explain further the effects of the many temperature and mechanical variables on the rate of oil consumption and oil dilution when only one factor was allowed to vary at a time. The dynamometer apparatus and the engine used are described, together with the test routine, and an analysis is made of the result of wear of the test engine. The “standard” conditions under which the test runs were made are stated.
1924-01-01
Technical Paper
240031
A Ludlow Clayden
Describing the three ways in which water may reach the oil-pan, the author says that the danger-point for water accumulation is reached when an emulsion becomes too highly viscous or when an accumulation of free water reaches the pump intake. The effect of using an emulsifying oil is explained and consideration is given the quantities of water actually deposited because of cylinder-wall condensation. An emulsion of oil with water up to 5 or 6 per cent differs hardly at all from the pure oil so far as film-forming and lubricating qualities are concerned. On the other hand, with an oil that is absolutely non-emulsifying, the tendency is for the water to segregate and collect in comparatively large globules. The ability of an oil to absorb a small percentage of water has the advantages of minimizing the danger of complete failure of oil circulation when starting in cold weather and of reducing somewhat the rate of piston-ring and cylinder-wall wear.
1924-01-01
Technical Paper
240020
Edwin M Baker
The quality of plated steel may be tested by exposing the article to the action of a salt spray and noting the appearance at intervals. A numerical method of rating the appearance is presented, and the rust resistance of steel plated with nickel and copper is shown to be dependent on the thickness of the plating. The effect on the salt-spray resistance of some common variables in nickel-plating, such as boric acid, ferrous sulphate, current density and defective steel, is disclosed and charted. The need of close technical control of the plating process is indicated, and some of the advantages of controlled electroplating at high current-densities are set forth.
1924-01-01
Technical Paper
240021
A J LYON, SAMUEL DANIELS
The importance of the development of a light alloy for use in parts that are subjected to elevated temperatures has already been emphasized in many papers, among which that by S. D. Heron on Air-Cooled Cylinder Design and Development4 should be particularly mentioned. It was with this purpose in view that the foundry of the Engineering Division of the Air Service at McCook Field undertook a brief survey of the alloying, the casting, the heat-treatment, the physical properties and the metallography of an aluminum-copper-nickel-magnesium alloy of the Magnalite type as sand-cast under ordinary foundry conditions. It was found that the alloying involved no particular difficulty. The casting, however, showed the necessity for proper pouring temperatures, gating and placing of the chills and the risers. Several photographs are shown illustrating satisfactory and unsatisfactory methods of molding pistons and air-cooled cylinder-heads.
1924-01-01
Technical Paper
240018
L A DANSE
The Cadillac Company has used S.A.E. 3250 steel for at least 8 years. This is medium nickel-chromium steel. Many other kinds have also been tried. Experience has shown that transmission gears made of carburized steel are not within 30 per cent as accurate as those made of oil-treated steel. This may be because of the fact that more attention has been paid to oil-hardened than to carburized steel gears. Efforts to control the distortion of carburized gears were unsuccessful. The hardening was done in salt pots, lead pots and open furnaces, heated by gas, oil and electricity. The same thing applies to spur gears. Oil-treated steel for rear axles has not been tried. When transmission gears were made from drop-forged blanks made by the conventional pegged-out process from flat stock they became oval. Upset gear forgings are used as fast as the forging suppliers can become equipped for the work.
1924-01-01
Technical Paper
240019
GORDON LEFEBVRE
Recent improvements in the mechanical equipment and the processes employed in the various car-assembling plants of a large motor-car-building company are described. As a result of the changes these departments have been transformed from the most unsightly parts of the factory into the cleanest, most comfortable and least dangerous. The processes to which special attention is devoted are those for the enameling of fenders and sheet-metal parts and such small parts as various stampings, forgings and malleables and cover the application of two coats of an asphaltic-base enamel and a subsequent baking at about 450 deg. fahr.; in body enameling they cover the application of three coats of similar material and baking at from 290 to 350 deg. fahr. The course of the various parts is followed from the time of their receipt to that of their delivery to the assembling department to which they belong.
1924-01-01
Technical Paper
240024
M L MCGREW
Because of tremendous demand for mass transportation over long distances in this Country, railroad equipment has become less and less suited for small transportation needs; but a large amount of small-unit transportation exists which can earn a profit for the railroads if they have the equipment best suited to handle it. Gasoline-propelled rail-cars have demonstrated their ability to meet the needs of this small-unit traffic. Types of such rail-cars now operating range from 25-passenger or 10 tons of freight capacity to 60-passenger or 30 tons of freight capacity; in certain services, their capacity can be increased by using trailers and by running them in trains operated by one driver at the front end, who has them under multiple-unit control, at speeds up to 50 m.p.h. and for from 20 to 50 cents per car-mile.
1924-01-01
Technical Paper
240022
ARTHUR T UPSON, LEYDEN N ERICKSEN
Shortage of the most desirable kinds of wood for automobile-body purposes has necessitated the substitution of second-choice woods having the essential required properties and the buying of stock for body parts in cut-up dimensions that conform in size with those now produced in the cutting-room. An investigation by the United States Forest Products Laboratory as to the species, kinds, grades, sizes and amounts used by the automotive industry shows that maple and elm comprise over one-half the total amount used and that ash and gum constitute one-half of the remainder. Although the quantity of ash used has not decreased, the increase in the production of medium and low-priced cars in the last few years bas caused a proportional increase in the demand for maple and elm.
1924-01-01
Technical Paper
240025
E J BRENNAN
A brief summary of the history of motor rail-car equipment on the railroad represented by the author is given in his paper. Three gasoline-driven rail-cars were put into operation in 1910. The engine used for each car was a six-cylinder, 10 x 12-in., slow-speed, four-cycle reversible-type having overhead valves, an open crankcase and a 200-hp. rating, but experience has proved that the four-cycle reversible-type engine equipped with an air-operated starting-apparatus makes rather a complicated unit that is the cause of many difficulties. Details are given concerning these first three cars, their performance and the changes made in their equipment. In 1922, a two-car train consisting of a motorcoach and a trailer was installed. The coach is 28 ft. long, has a 12-ft. baggage-space, carries 30 passengers and weighs 28,000 lb.; the trailer is 32 ft. long, weighs 17,000 lb. and seats 36 passengers.

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