US2305518A - Rail car underframe - Google Patents

Description

' Dec. 15, 1942.

AQGJDEAN RAIL CAR UNDERFRAME Filed Sept. 14, 1940 3 Sheets-Sha e. 1

1 I INVENTOR- Qlbert CLDCUQ ATTORNEY A. s. DEAN RAIL CAR UNDERFRAME Filed se t, 14', 1940 w 1 s sheets-sheet v2 INVENTOR:

n WWW M um m w A Dec. 15, 1942. G. DEAN RAIL cm UNDERFRAME Filed Sept. 14, 1940 a Sheets-5M6; s

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Patented Dec. 15, 1942 The invention relates to rail cars andmore particularly to the underframe structure of such cars, and is variant of the underframe structure} shown in my prior co-pending application'Serial I No. 296,026, filed September 22, 1939;

According to this earlier construction, the underf rame comprises an intermediate?longitudinal box-section center sill portion arranged directly; in vlinewith and adapted to directly receive theburfing loads from the couplers,jand this sillis connectedthroughout its length and atfrequent intervals to the side Walls through deep trans:

verse floor beams and bolsters, connected at their ends to the side Sills of the underframe formedv by the reenforced lower chords of the trussed side walls. The said intermediate portionof the cen ter sill passes through the bolsters andprojects at its ends some distance beyond the bolsters ad- I jacent the opposite ends of the underfrarne., It I is extended to the end silland the vertical collision postssecured thereto by vertically deep and laterally widened sill extensions 'which iorm; a pocket between, them for housing the draftgear r;

connected to. the coupler. longitudinal members of the underframe are further tied together into a unitary underframe by;

The transverse and longitudinal stringers secured to thejbolsters and floor beams and transversely corrugated floor sheeting secured to the end sills, side sills, center" sill extensions and stringers.

' It is well known that, due to metal of which it is the elasticity'of the l fabricated,the center sill-of this arrangement will shortenslightlyiunder the heavy buifing forces to which it is subject,and

such foreshortening, in view of. its strong connection to the rest of the underframawilltend to foreshorten the entire width of the under-.' framefland to deflect the side wall trusses 'connected to the sides of the underframe',,unless the I parts entering into the structure are fabricated with suflicient strength to counteract this foreshortening. Such foreshortening of. thesidefsills of the underframe, vantage that it causes trussed side walls of the interior appointments of the car. cation above referred undue deflection of the body, and this'affects the In the appli for example, has the .disade to, undue deflection is avoided by strengthening the under frame to take 1 care of it. Strengthin the under-frame is, ,of. course, advantageous-in case of collision where G the shock is transmitted to the entire unden,

frameidirectlyfrorn the end sill and, in such case, it is desirable that the center sill, work in I conjunction with the rest of the underframe in However, in taking taking the collision load.

' nected ca t ihe, f n the inner faces of the draltflgear pockets At vvide' strong'colu" 'na dependently of the sill portion with strong normal bufflngiloads through the coupler, ter,v sill has sufficient conot. necessary, it-the cen .lumnar strength,-;to ,havetherest of. the underframework W h i ak these lo dsan it Y will-be obvious that, if the restof the underframe is not securedto thecenter silLto work with it, I I the sill under these nor mal loads will not cause deflectionvoithe rest 01]v the foreshorteningz of 'side walls,

the underirame and body It mtheremewall ec at-invention to} the rigidly connect d overcome the defectsof I I I center. sill, and thusmakeit possible. to lighten the overall weightotthe underframe by so con-- structing the underira'me that the center. sill unpendently of the restof theunderframe and con With theWe n d sill.

theunderfrarne working to'ge'therto resist it.

T01 achieve hi l i t, I the center 'sill,. extending d pl ers at oppositejends o' fv the car'; a strong co-j lum'nar' structureunconnected to the rest of the ends of this sill po guided in the bol'ste I sills sides of the said s lportion' ends, I pmopposite between thebolst e'r's and the end-sill which provlde'the sides of-"the draft gear housing pockets; i

The ends of theunderframe,between and includingthe end'sillaiid take the-relatively light: draft forces as compared with the bufflng forces To enable the saidportion of to work-with therest of the underframe-in case of'collision loadagainstathe end-sill or the :col- 7 end of the car,'I- providesaid A lision posts at. the

rigid shoulders which normally abut coacting faces on the rigid end underframe structures so that collision forces on, said structures are transmitted throughthem I said'center silliportionas well as to the rest of the underframe vHowev er, under normal but! I I II transmittedftoit through Ithe coue I plers'acts by itself to absorb 1110885108 115 .inde

where, in case of collision. nd p ibwoll si n e d, is transmittedbythefcenter-sill andthe rest or intake the portion of I I rectl'y in line withfthe 1 draft; gear, mechanism ass'ociated' ,Iwith the cou,

underframe, or alternatively connected atone I end only, except iiorl spaced slidingly fitted guides provided to" prevent, buckling: of th'e sill, I The' on extend beyond and are" s: and terminate between the where I they p rovide sill extensions; extending I the bolster; are rigid struc tures rigidly tied into the side walls and act' to through the-car body in columnar center sill portion extending betweenithe-dra'ft gear pockets .atthe opposite-ends of the tinderframe. i the: center sill frequent deflection forces due to the buffing loads acting on the center sill. Fatigue strains in the rest of the body structure due to the buning forces are'also avoided.

Other and further objects and advantages and the manner in which they are attained'will become clear from the following detailed description when read in connection with the appended drawings in which- Fig. 1 is a plan view of a car underframe, with parts broken away, showing the invention applied thereto; 1,

Figs. 2, 3, 4, 5, 6 and 7 are enlarged fragmentary sectional views, the sections taken, respectively, on the correspondingly numbered section lines of Fig. 1 and look ng in the d rection of the arrows'at the ends of the section'lines; Figs; 8', 9 and 10 are similar d agrammatic central lon itudinalsectional views through a car body equipped with the invention ,.showing, by means of arrows, the path through which the forces ma nly act, Fig. 8 indicating the draft forces, Fig. 9 the buff forces, and Fig. 10 the collision forces,

In the embodiment of the invention shown in Figs. 1 to 7, inclus ve-the underframe is built up almost wholly of formed strips oi. high strength steel such as high-tensile stainless steel, and in most respects follows the structure disclosed in my application above identifiedv It will be understood,'however, that'the invention is applicable to other types of underframe construction, the form selected being merely illustrative.

The underframe may comprise a main center sill portion in extending the greater portion of the length of the car and through gu d ng o enings in the bolsters H adjacent its ends: This sill portion terminates some d stance beyond the bolsters adjacent each end of the car, and these ends are substantially directly in line with the draft gear, indicated generally at 12, and connected coupler i3 at each end of the car. I

Each and of the sill thus forms the inner end 01' a draft gear pocket and is adapted to directly receive the forces in bufl' transmitted from the couplers I! to the associated draft gears l2.

From Figs. 4, 5, and 6, it will be seen that this.

sill portion 10 comprises a compact column built up of a plurality of formed sheet metal strips secured together as by spot welding to form a generally rectangular box-section structure hav-.

ing free edge flanges.

This sill portion is entirelyfree to contract and foreshorten under the bufiing forces transmitted to its ends, since it is not connected to the bolsters through which it passes nor to any other parts 01'. the underframe to transmit any of these buffing forces to the underframe. A1- ternatively, it 'mayh'owever be rigidly connected to the bolster and/or columnar structures 22, .22 at one end thereof. Such connection at but one end would not interfere with the, free contracnated generally by numeral l4 between the I bolsters.

The guides I4 may consist oi a sleeve [5 slidably receiving the sill portion l0 and strongly secured to two spaced vertically-deep transverse floor beams l6 through its top and side walls. The top may be directly welded to the bottom of the floor beams, while the side walls of the sleeve l5 may be secured by angles ll overlapping and welded through their respective arms to the floor beams and sleeve.

The sill portion l0 so mounted to have longitudinal sliding movement with respect to the bolster and the guides H would, without further provision, be inoperative to transmit collision loads directly transmitted to the end of the underframe independent of the couplers,. To enable this sill portion to act with the rest of the underframe and car body to take collision loads, I provide the sill portion ill with an enlargement, designated l8, directly abutting the inward face of each bolster, such enlargement, in

the form shown, consisting of a sleeve strongly tion or foreshortening of the sill throughout substantially its entire length. The sill portion I 0 is stabilized against bending under buiilng load by the guided connection with the bolsters, and additionally by a pair of spaced guides, desigwelded or otherwise secured to the sill. These sleeves provide shoulders, indicated at I 9, each shoulder directly abutting the corresponding shoulder 20 surrounding the opening in the bolster through which the sill extends. From this it will be seen that any collision forces transmitted tothe "bolsters are also transmitted through the abutting shoulders l9 and 20 to the sill' portion l0 extending between the bolsters.

The end portion of the underframe, including the bolster ll and'the end/sill 2|, is reenforced to take collision by a spaced pair of strong columnar built-up structures 22, see Figure '7, which are of vertically-deep section and increase in width transversely from the'bolster to the end sill, to both of which they are strongly secured. The laterally outer widened portions of these columnar structures are in line with the vertical collision posts 23 of the end wall, and'the space between these posts is further reenforced by a bufier casting 2l secured to the posts and sill.

These columnar structures 22, 22 form the sides of a draft gear pocket and receive between upper portion of the sill is guided by angles 28' secured to the verticalportions of members 22.

Of course, the underframe so far described is strongly reenfor'ced at the sides by the strong columnar side sills 21 which may also form the bottom chords of the side wall trusses, the vertical members of which are indicated at 28. Other and shallower floor beams 29 mayconnect the side walls between the bolsters and the floor beams I6 supporting the guides l5, and between the spaced guides l5 themselves. Similarly, the end portion of the underframe between the bolster and the end sill may be additionally transversely reenforced by the floor beams 30. Finally, the entire underframe may be stiffened and strengthened by the transversely corrugated floor sheeting 3|, indicated in Fig. 1, this sheeting being secured directly to the end sills, to the columnar structures 22, 22, and indirectly through longitudinal stringers 32 to the bolster and the transverse fioor beams I8, 29 and 30.

Since the ends of the underframe are thus strongly reenforced and tied into the side sills 'I'he spacedguides along its length prevent its and side walls of the body, the draft forces acting through the coupler the body without utilizing the center sill l0, since the draft forces are comparatively light as compared with the forces in bufi.

According to the form of the invention shown, the forces in buff are transmitted from the coupler l3 to a yoke 33 guided in the draft gear pocket and having an inwardly extending portion 34 directly engaging the outer abutment'35 of a ,bufi spring nest 36, the inner face of this spring nest engaging'the abutment 31 directly engaging the end of the sill.

In draft, the, draft spring nest 38 is compressed between the transverse wall 39 on the yoke 33 andabutment 40 which brings up against a, pair of draft lugs, as 41, one secured to each of the columnar structures 22 forming the sides of the draft gear pocket. a

The operation will be clearly apparent by reference to the diagrammatic showing in Figs, 8,

9 and 10, wherein corresponding parts are given corresponding reference characters. From the showing in Fig. 8, it will be obvious that, when couplers l3 are subjected to draft forces, as; indicated by the arrows, the forces will be transmitted through the draft spring nest 38 and draft lugs 4| to the reenforced .underframe structure between and including the bolster H and the end sill M, and through this reenforced forces are carried. not only by the portions underframe carrying the draft loads, but also end underframe structure, as well as through the longitudinal stringers corrugated flooring between the bolsters and, by reason of the connection of the underframe to the side walls, through the side walls also. The arrows of Fig. 8 indicate generally the path-of the main portion of the draft forces. It will be couplers are subject to draft forces.

. Refer now to Fig. 9 where the couplers ii are shown to be subjected to buff forces. It will be seen that these forces are directly transmitted through the couplers to the the yokes and buff spring nests 36 to the ends of the sill portion I0. Since the sill portion I is can very well be takenby and the transversely yokes and through derframe, and a center seen that sill portion H! is entirely idle, while the free to contract or foreshorten under the load,

none of the forces in buff are transmitted to the rest of the underframe or body structure, so that under these heavy bumng forces the body structure is relatively free from fatigue strains and from deflection such as might harm the interior appointments of the body. Since these normal buff loads are taken wholly through the center sill portion Hi, the rest of the underframe. especially that portion of it between the bolsters,

can be very considerably l ghtened by the usev of shallow floor beams 29, shown in Figs. 1 and 3, and otherwise.

Referring now to Fig. 10.

are shown applied directly where collision forces to the ends 'of the car underframe, it will be seen that here such a of the by the center sill portion In by reason of its shouldered engagement I9, 20 with the inner faces of the bolsters. It will be understood, of course, that the hollow bolsters I l are reenforced between their side walls around the openings therein to transmit these loads from the bolsters to the sill l0 through the shouldered connection. Thus, the center sill adds its effect in resisting collision to the rest of the body structure, while free to contract and foreshorten in bufl without placing any strain upon the rest of the structure.

bolsters adjacentltheends sill member extending between and through' openings in said bolsters and having its ends thereby with its ends jacent theends of the underframe bending under the buff and collision loads.

While Ihave herein shown and described a specificembodiment of the invention, it will be understood that changes; and modifications may be made without departing invention, and such changes and modifications are. intended to be included within the scope of the appended claims.

What is-claime'd is: v

1., A -railcar underframe comprising spaced of the body, a center beyond the bolsters in line with the draft gear to directly receive forces in buff, said sill being free to foreshortenun'der forces in buff without 5 7 having. normally direct shouldered engagement with the affecting the rest of the, underframe,'but

inward faces of the bolsters, whereby collision forces transmitted to the ends of the underframe are taken by said sill member aswell as the re,- mainder of the underframe.

2. A rail car underframecom rising end sills,

bolsters spaced from said end sillsglongitudinally extending members including side sills connecting the ends of said end sills and bolsters, center sill end extensions spaced draftigear' pocket between interconnecting the bolsters and end sills at each end ofv the un sill member extending between the bolster and guidingly supported in line with the'dra ft gear pockets, and arranged to directly receive ,the forces in buff, said sill member being free to foreshorten under forces ing the rest of the underframe, but having normally'direct shouldered engagement with I the inward faces of the bolsters, whereby'it assists in taking collision forces transmitted to the ends of the underframe. H r I 3. In a rail car underframe, draft gear pockets adjacent'the ends thereof, bolsters inwardly of said pockets and having openings thereinin line with said pockets, a center sill'member extending between the bolsters. guided in said bolster openings, and having its ends form the inner ends of sald'pockets, the center sill member having normally direct shouldered engagement with the inward faces of said bolsters, but being otherwise free topermit relative longitudinal movement between it and the rest of the underframe under bufllng forces transmitted to its ends.

. 4. In a rail car underframe, end portions stiffened and strengthened to take compression and tension loads and including a bolster at their inner ends, a center sill member slidably supported by said bolsters and terminating beyond the bolsters, draft gear mechanism arranged adin line with thev center sill portion, whereby to transmit forces in bufi to said center'sill member only independent of the rest of the underframe, the sill member having normally engagement with the inward faces of said bolsters, whereby it aids in taking collision/ forces transmitted to the ends of the underframe.

5. An underframe'for rail cars comprising end sills, bolsters inwardly spaced from the endsills,

center sill end extensions comprising spaced longitudinal members interconnecting I each said bolsters and the/adjacent end sill and forming the side walls of draft gear pockets, draft gear including a draft yoke and cushioning means disposed in each of said pockets, a rectilinear center from the spirit of the apart to provide a' in buff without affectdirect shouldered sill member directly in line with said pockets, extending at its ends between said spaced end extensions and forming the inner ends of the respective pockets, the rectilinear center sill member being free of positive connection to the rest of the underframe, at least, from one end thereof for substantially its entire length and adapted to take the forces in buff from the draft gear directly against its ends, whereby it is free to foreshorten under the action of the forces in buff without transmitting such forces into,the rest of the car structure, and means whereby all the forces in draft are transmitted from the draft gear to the longitudinal members forming the side walls of the draft gear pockets and from them through the rest of the underframe independently of said rectilinear center sill member.

6. An underframe for rail cars having inwardly extending draft gear pockets at its opposite ends,

draft gear disposed and guided in each of said pockets, a rectilinear centersill member in line with said pockets, having its ends form, respectively, the inner end walls of said pockets and arranged to receive directly on its ends forces in buff transmitted to the draft gear in the respective pockets, longitudinally spaced transverse members of the underframe supporting and guiding said center sill member the said center sill member providing the'sole main generally centrallyfarranged longitudinally extending strength member of the'underframe in the region between the, endmost of said transverse members supporting and guiding it and being free of positive connection to the rest of the underframe, at least, from one end thereof for substantiallyits entire length, whereby it is free to foreshorten under the action of forces in buff without transmitting such forces through it into the rest of the car body.

7. An underframe for rail cars comprising bolsters adjacent the ends thereof, end sills, draft gear pockets the sides of which are formed by spaced longitudinal members connecting .each bolster with the adjacent end sill, draft gear .disposed and guided in each of said pockets and means for transmitting the forces in draft from ends thereof, the center sill member being free of positive connection to the rest of the underframe throughout substantially the entire length thereof whereby it is free to foreshorten under the forces in buff transmitted to it through said draft gear without transmitting such forces into the rest of the car structure.

5 8. A rail car underframe comprising spaced transverse membersincluding end sills and bolsters, draft gear pockets adjacent the ends of the underframe having their sides formed by spaced longitudinal members interconnecting the bolsters, respectively, with their adjacent end sills, draft gear disposed and guided in each of said pockets and means for transmitting forces in draft from said gear to the longitudinal members forming the sides of the pockets, a rectilinear centersill member forming the sole main generally centrally arranged longitudinally extending strength member of the underframe in the region between the draft gear pockets and being supported and guided by certain of said spaced'transverse members arranged inwardly of the end sills, theends of said center sill member being directly engaged by said draft gear in said pockets and the said sill member being free of positive connection to the rest of the underframe throughout substantially its entire length whereby it is free to foreshorten under buff forces 'transmitted to its opposite ends through said ALBERT G. DEAN.

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