US 2620751 A
Description (OCR text may contain errors)
M. wA'rTER 2,620,751
UNDERFRAME FOR RAILWAY CARS AND SIMILAR VEHICLES Dec. 9, 1952 Filed Sept. 24, 1948 IN V EN TOR. MICHAEL WATTER Patented Dec. 9, 1952 UNITED STATES T T F F I C E UNDERFRAME FOR RAILWAY CARS AND SIMILAR VEHICLES Applicationseptember 24, 1948, Serial No. 51,045
The invention relates -to the construction of bodies for railway cars and similar land vehicles of long prismatic shape.
More specifically, the invention relates to a novel construction of an underframe provided with a center sill and designed for the indicated type of vehicles.
Among the objects of the invention is an underframe construction having .a center sill which is light of Weight yet strong enough to sustain the loadimposed on it, which lends itself to the economical manufacture of its component parts from sheet metal and to the convenient yassembly of such parts into the completed sill structureY and with adjoining parts of the underframe, which provides a maximum of space for equipment suspended beneath the underframe, which greatly facilitates the crossing of the center sill by wires, pipes and other accessories, and which is well adapted for the carry-through connection of bolsters, cross bearers and other transverse structural elements.
These objects and other advantages are yachieved by a generally X-section or hour-glass section center sill comprising a pair of generally channel or U-section sheet metal proles secured together back-to-back by their webs, having their upper yarms structurally connected to a floor shear panel and their lower arms to one or several longitudinally extending horizontal reinforcing plates, and being shaped to form with said shear panel and plates a closed box section below and, preferably, `also above the inter connected webs. The form of the center sill may appropriately be called X-section.
Several embodiments of the invention are illustrated in the attached drawings and described in the following.
In the drawing,
Figure 1 is a fragmentary diagrammatic plan View of one end of `a railway car Figure 2v is a fragmentary perspective View and section on a larger scale of the underframe of the sameV car, the section being taken along the line 2-2 of Figure l Figure 3 is a straight-on cross section of the center sill and the adjoining portion of the shear panel shown in Figure 2; and
Figures 4 to 8 are cross sections corresponding to Figure 3 but showing modifications of the center sill.
The railway car, fragmentarily illustrated in Figure l, comprises an underframe, side walls, end walls :and a roof which form together the stress-transmitting and load-sustaining struc- CTI.
ture. The posts of the side Walls are indicated at I0 in Figure 1; apart from this, merely the underi'rame structure is illustrated in greater detail in Figures l and 2; The side walls, end Walls and roof may be of customary construction. The body is supported at each end on a truck (not shown) by means of a center plate I I.
The underframe, illustrated in Figures 1 :and 2, comprises a center sill I2, longitudinal side sills I3, a shear panel I4 reinforced by transversely extending, longitudinally spaced upright Webs l5 and longitudinal stringers I6, I1 carrying the floor boards I8 together with the webs I5. The shear panel with its webs presents la, floor construction of great transverse stiffness. The side sills I3 serve not only for the reinforcement of the underframe, but also for the known structural connection of the underframe with the lower margins of the side walls of the body (not illustrated). The shear panel and its webs are formed by angle-section pans integrally connected with each other by welding along overlapping margins.
The center sill, illustrated in Figures 2 and 3, is formed by a pair of U, channel or trough sections IS, two superimposed bottom reinforcement plates 2i), 2I and the longitudinal midportion of shear panel Ill and its webs I5. The U-sections I9 have their vertically arranged webs 22 secured to each other back-to-back by several rows of spot welds 23. The upper arms 2t of the U-sections are spot welded :at 25 to shear panel iii. The plates 2t and 2l have their longitudinal margins overlappingly secured to each other and to the underside of the lower arms 26 of the U-sections by double rows of electric spot welds 2l.
The U-sections I9 have their webs 22' extended and connected to their arms 24 and 26 by diverging wall or web portions 28, 29 so that the latter form closed box-sectional structures with the midportion of shear panel I4 and plates 2B, 2l respectively. The lower bottom plate 2| is constituted by a flat strip or band, whereas the upper reinforcing plate 2d has horizontally arranged, iiat marginal portions and an inverted channelor V-section middle portion 3d, the arms or side walls of which are secured by welds 3| to the diverging wall portions 29. Plate 2Q divides the lower box section into a double box section.
In the embodiment illustrated in Figure 4, two channel or U-sections 32 are connected with each other by their central web portions 33 of relatively small height, the connection being made preferably but not necessarily by electric spot welding. The top arms 34 of the U-sections are connected to shear panel 35 and its webs 35, yand the bottom arms 3.' are connected to a flat web or plate 38 and an upper web 39 having a raised middle portion. Between the web portions 33 Iand the arms 31% and 3l, the channel sections 32 have their edge or wall portions 40 laterally outwardly offset toward 'the open side of the sections S2, thereby forming relatively large hollow sections which are closed by shear panel 35 and bottom plates 33, 39, respectively. The locations of the welds connecting the different members are conventionally shown in `the draw-1 ing. The remainder of underframe and body structure may be the same as illustrated by and described in connection with Figures l and 2.
Inasmuch as the embodiments illustrated in Figures and 6 are identical with the embodiment illustrated in Figures 2 and 3 in regard to the form of the channel sections and their connection with each other and the shear panel, identical parts are marked in Figures 5 and 6 by the same reference numerals used in Figures 2 and 3 land are not described again.
rThe center sill illustrated in Figure 5 has its U-sections I9 reinforced at the bottom by a strip, plate or web 4I of curved, for instance lpartcircular, section. Plate 4l is secured along its margins at 42 to the diverging or offset portions 29. rllhe strength of this sill, other things being equal, is less than the strength of the sill illustrated in Figures 2 and 3 while weight, number of members entering into the structure and the number of connecting welds are reduced.
In Figure 6 there is only one bottom web or plate 43 having horizontal marginal portions 44 secured to the bottom arms 26 of the channel sections I9 and having its mid region 45 downwardly arched. This form increases the area of the closed box section formed by plate 43 and the diverging portions 29 of the channel sections.
The channel sections 45, 41, respectively, illustrated in Figures 7 and 8, are in the region of and above the connected vert-ical webs 22, the same as in the embodiment illustrated by Figures 2 and 3, so that again the same reference numerals are used without repeating the description of the parts in question.
The bottom arms 48 of the channel sections 46, illustrated in Figure 7, are each adje-ined by an inwardly and downwardly facing angle-section portion 49. These portions 49 of both members 46 constitute together a large-area inverted channel section which is `closed by lower bottom plate 50 and sub-divided by the inverted V-section portion 5I of upper bottom plate 52. Plates 50 and 52 have their m-argins secured to the arms 48 of the channel sections 46 'as in the previously-described embodiments per Figures 2, 3 and 4.
The webs 22 of the channel sections 41, `illustrated in Figure 8, are adjoined by wall portions 53, quarter-circular in section, by outwardly diverging wall portions 54 and the lower arms 55. The lower arms 55 are again secured to the margins of bottom plates 55 and 5l. rI'he upper bottom plate 56 has its inverted V-section mid portionoverlappingly secured by spot welding at 58 to the diverging portions 54 of the channel sections 47.
Center sills of the illustrated types for cars of passenger trains may, for instance, -be about high and 14" wide, have top and bottom Yarms or ilanges of about 3 width, and be made of high-tensile austenitic chromium-nickel steel of' 0.20 gauge. Sills manufactured in this manner and having the general cross sectional forms. illustrated in Figures 3, 4, 7 and 8 were found tohave a compression strength of -about 1,150,000v to 1,350,000 pounds. The members entering into the sill construction can easily be formed from coil stock on draw or roller benches, :and they can easily be -connected with each other by electric spot welding, all the welds being easily accessible.
All illustrated embodiments have the following features in common: a pair of channel, trough or U-sections are secured back-to-back by their vertically arranged webs; the horizontally arranged top arms of thevchannel sections are secured to floor structure of great transverse stiffness which is substantially coextensive with the length of the channel sections and the width of the car; the horizontally arranged bottom arms or adjoining lower portions of the `channel sections are secured to and interconnected by one or more narrow elongated plates; the edges between or adjoining marginal -portions of the Webs land the horizontal arms of the channel section are laterally offset 4relative to the middle portion of the web toward the open side of the respective section'or, differently expressed, the marginal por tions of the webs diverge toward top and bottom of the sill,rrespectively; and the ofsetor diverging porti-ons formV closed box-section structures with the shear panel and plates, respectively.
The new center sill in its diierent forms has: a great moment of inertia in regard to its liorizontal neutral axis giving the sill great vertical bending strength. The moment of inertia in regard to the vertical neutral axis is considerably smaller, but horizontal bending of the sill is prevented by the great transverse stiffness of the iioor structu-re and the connection of the latter with the sill. While only the top of the center sill is connected with the floor structure, the moment of inertia in regard to the vertical neutral axis is suilicient to prevent the lower portion of the center sill from buckling out laterally.
It is self-evident from the `drawing that equipment and accessories can be placed on both sides of the center sill and extend to points adjacent the webs of the two channel sections connected with each other. rIhis means that in the new underf-rame construction the center sill-in comparison to widely used box-section Icenter sillsoccupies only a small fraction of the space underneath the floor of the car, which space becomes increasingly valuable with the increase in number and size of equipment of modern railway cars.
It is, furthermore, self-evident from the drawing that the solid web of the center sill formed by the connected individual webs of the two channel sections, permits a much easier piercing and extension of pipes, wires, etc., therethrough as compared with center sills of closed boxsectional form over their entire height while, on the other hand, the advantages of box-sectional structures are retained to a large extent in all illustrated embodiments of the invention by the box-sectional formations above and below the solid web. The solid web, furthermore, permits the effective connection of the two halves of bolster beams and other cross bearers and of transverse structural elements in general with the center sill and with each other so that stresses are transmitted across the sill without interruption.
Though several r'embodiments' of the invention have ybeen illustrated anddescribed, it is to be understood that the invention is susceptible to Various otherA modifications and refinements and isnot limited to the illustrated embodiments. For instance, the box-sectional portion of the sill may be provided at the top or at the bottom only, though the illustrated constructions having a box-sectional portion at the top as well as at the bottom is considered best. Another ini-nor modification would alsov consist in the substitution of spot welding by other connecting means, for instance riveting.
What is claimed is:
1. In an underframe for railway cars and similar land vehicles of elongated generally prismatic shape, a sheet metal center still comprising a pair of channel-section members, each having a bottom wall, side walls and wall portions interconnecting the margins of the bottom wall with the inner margins of the side walls, said members having their bottom walls secured back-to-back in upright position, said interconnecting wall portions diverging laterally outwardly in the direction toward said side walls and forming between them one hollow section in the upper and another in the lower region of the sill, a shear panel coextensive with the length of said members and the width of the underframe being structurally secured to the side walls and closing said hollow sections in the upper region of the sill, and an elongated sheet metal strip secured to the side walls and closing the hollow section in the lower region of the sill.
2. In an underframe for railway cars and similar land vehicles of great length and small width, a sheet metal center sill comprising a pair of channel-section members, each having a bottom wall, side walls and wall portions interconnecting the margins of the bottom wall with the inner margins of the side walls, said members having their bottom walls structurally secured back-to-back in upright position, said interconnecting wall portions diverging laterally outwardly in the direction toward said side walls and forming between them one hollow section in the upper and another in the lower region of the sill, a shear panel coextensive with the length of said members and the width of the underframe being structurally secured to the side walls and closing said hollow sections in the upper region of the sill, longitudinally spaced upright webs integral with said shear panel and extending over the width thereof thereby forming a transversely stii oor structure, and an elongated sheet metal strip secured to the side walls and closing the hollow section in the lower region of the sill.
3. In an underframe for railway cars and similar land vehicles of elongated generally prismatic shape, a sheet metal center sill comprising a pair of longitudinally arranged channelsection members, each having a bottom wall, side walls and wall portions interconnecting the margins of the bottom wall with the inner margins of the side walls, said members having their bottom walls secured back-to-back in upright position, said interconnecting wall portions being laterally outwardly oiset relative to said interconnected bottom walls and forming between them one hollow section in the upper and another in the lower region of the sill, a transversely stiff floor structure vstructurally secured to and forming the sole interconnecting means between the side walls in the upper region of the silL, and a: narrow longitudinally arranged sheetr meta-1 band secured'to and vinterconnecting said'. members belowi theirY bottom wallsY so that itV closes the hollow sectionin the lower region of the sill.
fl. In an underirame for railway cars and similar long but narrow land vehicles, a center sill comprising a pair of channel-section members, each having a bottom Wall, side walls and at least along one of its edges a wall portion interconnecting the margin of the bottom wall with the inner margin of a side wall, said members having their bottom walls secured backto-back in upright position, said interconnecting wall portions diverging laterally outwardly from the bottom walls and forming between them an upwardly open hollow section, a reinforced oor structure designed as a main load-supporting element being structurally secured to and interconnecting the side walls in the upper region of the sill, and an elongated sheet metal strip being secured to and interconnecting said members below their bottom walls, one of said floor structure and metal strip closing said hollow section to form therewith a closed box-sectional structure.
5. In an underframe for railway cars and similar vehicles, a sheet metal center sill comprising a pair of U-sections, each having a Vertically arranged web and horizontally arranged upper and lower arms, said sections facing in opposite directions zand being structurally secured together back-to-back by their webs, the edge portions of each U-section, which connect the web with the arms being offset toward the open side and the horizontal middle plane of the respective section, a horizontal shear panel structurally secured to and alone interconnecting the upper arms of both said sections, said panel extending over the length of the center sill and substantially over the width of the underframe, said shear panel and said offset edge portions adjoining said upper arms of both said sections forming together -a closed box-sectional structure, and a pair of superimposed narrow elongated plates structurally secured to and interconnecting said lower arms of both said sections, said plates being vertically spaced from each other between said last-named arms and forming together and with the adjoining oiset edge portions a closed double box-section.
6. In an underframe for railway cars and similar vehicles, a center sill comprising a pair of U-sections, each having `a vertically arranged web and horizontally arranged upper and lower arms, said sections facing in opposite directions and being structurally secured together back-to-back by mid portions of their webs, edge portions of the webs adjoining the lower arms being arranged at least partly in planes diverging laterally and outwardly from said mid portions, a horizontal panel structurally secured to and interconnecting the upper -arms of both said sections, and a narrow elongated plate of inverted channel section having diverging side walls and lateral horizontal flanges being structurally secured by its anges to said lower arms and by its side walls to said edge portions of both said U-sections.
7. In an underframe according to claim 6, a narrow elongated plate secured to the underside of said channel section and to said lower arms, said plate having its mid portion spaced from the channel section to form a closed box-section therewith.
8. Underframe for railway cars and similar 7 vehicles, comprising a center sill of X-section, a floor structure stress-transmittingly secured to and alone interconnecting the upper arms of the X-section, and `a longitudinally elongated plate structurally secured to and interconnecting the lower arms of the X-section.
REFERENCES CITED The following references are of record in the le of this patent:
Number Y 8 UNITED STATES PATENTS Name Date Krause July 17, 1894 Brown et al Nov. 30, 1920 Carns Mar. 26, 1929 Milburn Feb. 10, 1931 Dean June 8, 1937 Dietrich Nov. 19, 1940 Lundvall May 25, 1943 Dean Oct. 19, 1943 Dean Jan. 9, 1945 Ledwinka Apr. 18, 1950