US2093579A - Railway car - Google Patents

Description

sept. 21, 1937. 4 w. a. 51cm v RAILWAY cm 4 sheets-sheet 2 Filed Sept. 2, 1933 A sebum, 1937. w. B; swim 4 Sheets-Sheet 4 RAILWAY GAR Filed Sept MN ww MN MN @im S N Patentedl Sept. 21, 193.7

UNITEDV STATES,

PATENT OFFICE RAILWAY can wiluam stout, Detroit, Mien., signor to" y Pullman-Standard Car Manufacturing Com pany, acorporation o! Delaware Application September 2, 1933,4 Serial No. 688,000

The improvements in -air craft made in the last few years by using shapes and lines suited to the performance sought has stimulated the interest of automotlveengineers in reforming ltheir designs, and salesmen have again made streamlining a theme of sales talk with customary misuse to the deception of the ever gullible public that still buys many oddities as streamline cars.

`becomes an enveloping stream ilowing over theV bird from front to rear. The fastest fish is built to move through a supporting stream of water running from head to tail. These naturalshapes l are streamlined to suit air in one instance, and` water in the other. They teach much about air. andsubmarine craft, but give little help on a rail carortrain. A A land vehicle is supported on the solid ground and runs through air which has varyingmotionI relative to the land in one respect and relative to the train in another respect; and the air near the ground has diierent pressure characteristics from 4free air -well above the ground. V'

-The crab and turtle are shaped to res'tornive on theearth and letthe water flow over them,

` `in any-direction with little resistance. y But water is noncompressible and its motion relative tothe crab or turtle is slowx'neasured/in feet or inches per minute. Air, on the other hand, is .compressible, and often moves rapidly relative to the earth on which the vehicle is propelled in another di-f rection at high speed, I

l l Theoretically the contour of acar should minimize the resistance of. air without regard to the relative direction of' ow; andA if railroads could-' lbe built anew without regard to cost, many problems could be avoided, but any new rail' car o'r train must run on existing tracks within existing track clearancesand provide suitable additional' v room'for passengers and space forfreight. Car resistance is made up of parts due "to weight (gravity) that appear as track resistance,

journal friction, etc., and also parts d ue 'to the sizeandl shape of the car that determine-the .rearward components of wind,` actual or relative,

' yand low pressure areas induced by the movement 1 claim. (ci. 10s-2)- sion bridge when people walk over it. The cause and the remedy for track and roadbed diihculties are easily determined from such pictures. Theexcessive weight is the destroyer and must be reduced.-

The parts of car resistance in the second group are complicated by the fact that the path of the car, although through the air, is in the vicinity of the earth in shapes that vary from a tun nel through a cut to ties and ballast on a fill or a bridge.. Each of these shapes has its own peculiar reaction with the passing car and the intervening a.ir, and makes resistance in proportion as the adjacent surface of the car and the earthl approach the relation of a turbine run backwards. The turbine eiect is particularly noticeable between the broken, irregular underside of conventional carsand the cross ties and ballast over which it travels; i y

Wind pressure from the side, either directly,

or any position having a transverse component,

learned,because.the greatweight of conventional Lcars has prevented these transverse forces from showing their real overturning tendencies.

But thereduction in weight of conventional `structures wouldreveal a new problem:rkeeping the cars from being blown1 over.`

Itispeculianvbut none the less true, that a head-wind at approximately 16". /from the direction of travel produces the-'greatest overturning eiIect.. 'Ihis is because the pressure on the Windward side is aided by the suction or low pres- -sureproduced on the opposite side. I The conventional carshapefostersthis condition both by presenting large ilat areas on the Windward side and by presenting obstructions oi almost' every kind to theeasy flow of the air from the Windward side -to the leeward side, which would tend to maintain substantially uniform pressures atopv faster with'less power as compared -with prior .has a-"peculiar eilect, of which little has been cars, and also able to hold the track lin spite of the greater relative wind velocity at angles to the line of travel which arise from the increased speed, all with appropriate cost; and otherwise y to provide-'a rail car 'which combines the ad- Yvantages of reduced air resistance with the modl-V fying requirements dictated by clearance'lines and desired passenger and/or freight carrying capacity.

Further and other objects and advantages will become apparent as the disclosure proceeds and the description is read in conjunction with the accompanying drawings, in which Fig. 1 is a side, elevational view of a preferred form of the invention, a fragment of the body being broken away to expose one of the driving motors;

Fig. 2 illustrates in plan the air currents that result from the car moving against a 16 wind, the arrow indicating the direction of car movement;

Fig. 3 illustrates the passage of air currents above and beneath the car;

Fig. 4 represents a standard Pullman car moving against a 16 wind;

Fig. 5 illustrates the effect of a cross wind on a standard Pullman car, the scale being the same as that in Fig. 3;

Fig. 6 is a diagrammatic, perspective .view showing the general organization of the car;

Figs. 7 through 19, inclusive, are diagrammatic, transverse, cross sectional views of the body framework, the several views being taken on section lines (Fig. 20) corresponding to the respective figure numbers, and like cross sections being indicated by like section numbers; the dotted lines in Fig. 11 indicating the modifications corresponding tovsection I I'-I i';

Fig. 20 is a plan view showing the interior of the car;

Fig. 21 is an enlarged, side elevational view of the `car nose, the structural framework being shown in dotted lines; and

Fig. 22 is a front end view of the car.

At the outset, it should be understood that the selection of certain preferred and modified forms of the invention for illustration and description is merely for the purpose of disclosure, for the invention may be variously embodied within the scope of the appended claim.

General organization (Figs. 1 and 6', particularly) .`porting structure that would otherwise-be required if the driving equipment were placed at a higher level. Accordingly, a direct drive is used with the power plant mounted on one trucks.

The second broad concept is to divide the power l plant into at least two units so that they may be mounted at the sides of the truck and consequently permit the car body to rest relatively low on the supporting trucks. 'I'his arrangement, besides placing the principal weight close to the track, has the further advantage that passenger space is not sacrificed in the attainment of a low center of gravity.

The mounting-of as heavy an object as a driving motor upon the car truck requires in ordinary practice exceptionallystrong supporting elements, for the car truck is subjected to rapid impact loads as the car moves along the track.

of the car 'I'he provision of this normally required strength to counteract the impact loads is obviated in the present case by providing resilient wheels which are capable of absorbing a large portion of the impact shock. In this way, an exceptionally light truck may be used even though it carries a driving motor outboard on opposite sides of the truck.

Since the car of this invention is characterized by its light-weight and high speed, its resistance to air becomes an. exceedingly important factor. Cross winds which have no marked effect on conventional railway cars may very easily overturn a high speed light-weight car unless the car body is properly shaped to resist the overturning force. Curiously enough, a wind at an angle of 16 to the direction of travel produces the greatest overturning e'ect and at the same time offers substantial resistance to car movement. Therefore., in order to give the car stability upon the track and to minimize the resistance of air to forward travel, the car body of this invention is shaped with these problems in mind, and, furthermoref with a consideration of such limiting. factors as the A. R. A.-clearance line, the passenger space required, the appearance of the car, etc.

The illustrative embodiment of the invention, which is shown in diagrammatic perspective in Fig. 6, clearly shows the application of the several v fundamental concepts mentioned above to the general organization of the car.

The car body, it will be observed, comprises a space framework of metal tubing thatis welded together to form a rigid unitary bddy. The framework is covered by a metal skin 5i which is secured to the framework and assists in resisting tortional strain.

The body is supported by a front truck 52 and a rearA truck 53, the former having internal combustion engines 54 and 55 mounted outboard on opposite sides of the truck. The front truck includes wheeled axles 55 and 51, diametrical ends of which are driven'by the motors 54 and 55. The other diametrical ends of the axles 5'6 and 51 'are equipped with brake operating mechanism, gen- .erally indicated at 58.

The rear truck 53 includes wheeled axles 59 and GEB, each of which are braked by mechanism corresponding to the mechanism 58 of the front truck.

The axle of both frontand rear trucks are equipped with what may be termed resilient wheels, and this term is intended to include all ers 64 pivotally suspended from the truck frames.

AThe truck frames of each truck are fabricated of metal tubing welded together in such manner as to produce space frameworks of necessary strength, and at the four corners of each frame, a leaf spring 65 projects toward the adjacent axle -where it connects to a journal $6.' The point of connection between the projecting spring and the journal is, in each case, beneath the axle, so that the truck is underslung with respect to the axles.

Driving and braking forces applied to the car y axles are transmitted to the truck frames by radius rod GI.y Other radius arms 68 which connect the worm gear casing 59 to a xed point on the car truck,in` this case, the transmission housing IIL-take the thrust of the driving worm. Braking forces arel resisted by torque arms 'il frame.

The exterior ofl the car is best illustrated in Fig. 1, the front of the car being to the right. The body, as will be seen, is elongated and has a taper? ing blunt nose and tail to reduce wind resistance. 'I'he outer surfaceof 'the car consists of smooth broad curves. well blended together to produce a graceful appearance and v'at the same time directing the air currents around the car with minimum eifort. The windows 13 are flush with the outer skinl and are made stationary as it is contemlliated that a forced system of ventilation will used.

vThe bottom of theucar is uninterrupted in out-v Bod@ shape It is totally impractical to shape the car body so that it most eifectively reduces wind resistance. In the first place, a perfectly streamlined body presents a somewhat grotesque appearance and certainly is not pleasing to the eye. It may be said that a car shaped so as to offer the absolute minimum resistance to air currents would not respond to the art fundamental, a term which is used in art to signify certain relative proportions which have been found to have grace, 'symmetry and pleasing appearance. It is, therefore, de-l sirable =to sacriilce some of the advantages of reduced wind resistance in order to give vthe 'cdr a graceful appearance.-

The American .RailwayrAssociation clearance line l.(Figs. 3 and,5) imposes another limitation upon the shape of the car. The clearance line,

asis well known, fixes the'outside limits for car body contour, including all equipment that is carried by the car. No part of the car is supposed to project'beyond this limiting line, and

` all American car buildersrespect the rule.

A third limiting factor which forces a compromise in the shape of .the body is the interior space required for passengers and'baggage. The car body must be 'suiiicientlyf wide at its base to give reasonable seating capacity. But at the top it need not be as wide.y The sides of the car may, therefore, taper inwardly toward the top, and this enables cross winds to be properly dealt with.

A body shape which satisfies the three principal requirements set forth above is one which is substantially ovate in cross section and is provided with a tapered bluntnose and tail. "Wind tunnel testshave demonstrated that such a shape has low wind resistance both-as against a front wind and a cross wind. In addition, the car is graceful, affords ample passenger space. and can easily `be madel within the American Railway Association clearance' lines.

ltyreferring now to Figs. 1, 2, 3, vand '1-19, inclusive. a more accurate conception of the body shape may be discerned. It will nrstbe observed 1 that all lines of the body are blended ltogether with smooth broad curves and that there are no vprojections which impede the flow of air rover the surface of the car.

l The general ovate,v cross sectional shape, as

t shown 'in Figs. 7-19 has `several distinct advantages over Vconventional lcross sections. Air curwhich connect the brake housing-12 to the truck rents striking the sideof the car (Fig. 3) at right angles to the longitudinal axis of thecar are' lcarried along 'the upper and lower curved surfaces with comparatively little resistance andsince the side ofthe car tapers upwardly, there will be but a small area. at the side ofthe car .which'produces eddy currents. On the lee side ofthe car, there is a relatively smalllow pressure area, as indicated in Fig. 3. for in the same" manner that the smooth curves andl slopingV side wall carry the air currents over and beneath the', car on the windward side so also do they tend,

to reduce the low pressure on the lee side.

i A comparison of the aircurrents in Fig. 3 with those in Fig. 5 shows clearly the advantage ofy the ovate, transverse, cross'section as compared with a standard pullman car.

'I'he shape of the car in plan also contributes` to the low wind resistance which it offers to forward movement.V Since `the nose and tail are blunt and tapered, air currents striking the car from the most unfavorable angle.. viz.' 16 from the direction of travel, -will follow generally the contour of the body and will produce .a much smaller low pressure area on the lee side than.

theordinary pullman car. (Fig. 4).

'Ithas already been vstated that the possibility of overturning the car. becomes a very important consideration when the car is made of light weight materials and travels at a high rate of -speed. The relatively small low pressure area `by wind resistance.

on the leeward side combined with a reduced high Vpressure on the Windward side effectively eliminate the possibility of overturning the car The overturning eifect i-s further minimized bythe fact that the car body .rests relatively low upon the supportingy trucks so that'the force 4oi the wind acting through the center of pressure.' indicated by C. P. in Figs. 3 and 5. has a relatively short lever arm as compared with the lever arm in an ordinary-car.

The blunt tapering nose and -tail in their vertical projection "have the same eifect upon breaking the wind as the sides of the car have in allowing crossr winds to slip easily over and beneath the car.

The transverse cross-sections, taken adjacent the ends of the car, are more truly egg-shaped or ovate than the intermediatesections. but for convenience the term ovate will be used'to designate the characteristic shape which includes i upwardly4 tapering side walls and' smoothly v rounded top and bottom walls. As ,the intermediate sections are fuller and more nearly roundthan the end sections, the term ovaterotundate may be used to more specifically describe their shape.

The term ovate rotundate wherever it appears in the appended claim is used' in the sense above described.l This term also implies that the.7

car has its greatest width in the region of the floor level and a smaller width in the region of (above the lower curve) are substantially vertical. The essential relationship dei'lned by the term ovate rotundate is that the body is shaped (consistent with the above) so that when a horizontal wind strikes the car at an angie with respect to the longitudinal axis of the car, there 5 will be a substantially greater tendency for the air to pass over the car than beneath it (dlsre glarding the spacing of the -car body from the ground) but that in either case, the air is guided in its path across the car by smooth broadly rounded unobstructed surfaces. It is this increased tendency for the air to pass over a car of ovate rotundate form than beneath it and the spacing of the car body from the ground so that substantial quantities of air can pass beneath the body, that lowers the center of pressure as compared with a car of similar dimension that does not have this tendency (as for example Adams 489,912 and Zimmerman 542,746) Preferably the car trucks are provided with a metal skin 89 in the form of a pan, which carries out the reduced wind resistance eiect, but do'es not interfere with the relative movement between the truck and body. The pan is secured to the bottom of the truck frame by screws, or 2-3 other suitable means.

I claim as my invention:

A light-weight, high speed railway vcar for ground railservice having smooth, continuous and substantially unobstructed surfaces comprising a car body mounted on trucks and having a 5 relatively low center of gravity, nose and tail portions constructed with curves shaped to citer relatively small resistance to head winds and reduce drag respectively, the body as a whole being spaced a suillcient distance from the rail 10 that substantial quantities of air may pass transversely beneath the car body, said body having a substantially uniform cvate rotundate cross sectional form from end to end which gives the body a relatively low centerfof,.pressure and l5 which permits side and oblique winds to pass above and below the car body with relative ease and minimum turbulence, the car beig` oi' sumcient length so that the ovate rotundate cross sectional form of the car causes the air pressure 20 Y on the Windward side to be reduced, that on the leeward side to be increased, and the tendency of the car to overturn in strong oblique side winds to be held to a minimum. v

- WILLIAM B. STOUT.

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