US2788750A

US2788750A - Railway car underframe construction

Info

Publication number: US2788750A
Application number: US403742A
Authority: US
Inventors: Henry M Priest
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1954-01-13
Filing date: 1954-01-13
Publication date: 1957-04-16
Anticipated expiration: 1974-04-16

Description

April 16, 1957 H. MQPRIEST RAILWAY CAR UNDERFRAME CONSTRUCTION Filed Jan. 13, 1954 lwentor: HEMP/M P0557,

fizz War/75 United States Patent RAILWAY CAR UNDERFRAME CONSTRUCTION HenryM. Priest, Pittsbni gh; 1 21., assi ns:- to United States Steel Corporatiomacorrioration of New Jersey Application January 13, 1954, Serial No. 403,742

2 Claims. (Cl. 105406) The present invention relates generally to the construction of railway cars and more particularly to the construction of the center sill and cross members of car underframes. I

In the construction of car underframes' prior to my invention, the center sill was usually made up of a pair of 2 sections positioned with their top flange ends extending toward each other and welded together to form" cross bearers were provided with a top cover plate which extended longitudinally along the tops of the bolsters and cross bearers from one side sill of the underframe to the other usually passing over the center sill at its point of junction with the bolsters and cross bearers. Each of the bolsters and cross bearers was provided with a top cover plate which was extended over the top of the center sill or wasbutt welded to'the outside top edges of the welded 2 section. Where the cross members crossed over the center sill, an eccentricity of construction resulted with consequent inevitable notch effects in the welding of the cover to the center sill which produced undesirable stress concentrations which in turn formed points of weakness. This form of structure also resulted in an uneven top surface on the underframe which necessitated the provision of additional elements to compensate for the unevenness so that the Wood flooring of the car would be uniformly supported. When the covers of the top members were butt welded to the center sill, the two lines of butt welds that resulted, together with the line of weld that held the Z sections together, formed three discontinuities in the base metal which sometimesbecame sources oftrouble. This latter construction is obviously inferior to a continuous single plate structure.

Another disadvantage inherent in the use of 2 sections for forming center sills wasthe amount of difiiculties encountered in the rolling of the sections. Rolling mills have always had difliculty in satisfactorily filling out the long thin top flange of the 2 section. Since it was necessary to-forrn the center sill by putting two 1 sections together and welding along the center line of the sill, the

variations in length of these top flanges caused welding difficulties because of the resultant varying width of gap which frequently occurred in the 40 or foot length of railroad cars. Due to the fact that the 2 sections were unsymmetrical in shape, they were also subject to differential cooling when rolled which warped the section so that it was frequently necessary to straightenit after r lling. i

The unsymmetrical nature of the bottom flange of each 2 section about an axis through the vertical web gave rise to a detrimental torsional effect when loads were applied to the center sill. There was also an eccentricity between the center of gravity of the center sill and the center line of the coupler through which end loads were Patented Apr. 16, 1957 2 applied to the sill which produced additional bending stress in the center sill.

I propose to eliminate the foregoing disadvantagesby forming the center sill from a relatively easy to rollsymmetrical H beam and covering the center sill, bolsters and cross bearers with an integral cover which lies wholly izi one plane. The formationof a'n int'e'gral coverin'g'is accomplished by providing a cover plate on the center sill which is cut out at intervals therealong' where the junctions with the bolsters and cross bearers occur to permit the insertion of the cross member covers. The center sill cover plate and the cross covers are tirade integral in a common plane by welding the abutting edges of the cross members and the center sill cover. The cross covers and the center sill cover are also welded to the tops of the webs of the center sill. By using a center sill cover plate which is rolled separately from the rest of the center sill, the width and the thickness of the cover plate can be varied to adjust the center of gravity of the center sill to coincide with the center line of the coupling. No such means of adjustment were present in the prior art center sills'formed with 2 sections.

It is, accordingly, an object of my invention to provide a car underframe construction wherein the center sill, body bolsters and cross bearers are formed into an integral unit having a continuous cover plate of unitary construction extending wholly in one plane whereby stresses are distributed uniformly and concentrations of stresses are minimized.

Another object of the invention is to provide a construction which may be easily assembled from conventional H beams and plates to form a car underframe which is stronger than those constructed prior tomy invention.

A further object of the invention is to provide a car underframe center sill, bolster and cross bearer construction having a flush top cover' plate whereby car flooring may be supported directly thereon without the necessity of providing additional leveling support construction.

The nature of the invention and its distinguishing features and advantages will be fully apparent from the following detailed disclosure and the appended claims when read in connection with the accompanying drawing in which:

Figure l is a perspective view of a car underframe embodying the construction of my invention;

Figure 2 is a partial view in perspective showing the center sill, bolster and cross bearer construction of my invention;

Figure 3 is a top plan view showing the construction of the center sill of my invention adjacent its end; and

Figure 4 is an end elevational view of the center sill which illustrates partly in dotted lines the source of the web sections of the center sill.

Referring more particularly to the drawing, reference numeral 2 designates generally a car underframe constructed according to my invention. The underfi'an'ie 2 consists of a pair of side sills 4, end cross members 6, center sill 8, bolsters 10, cross bearers 12, cross ties 14 and longitudinal stringers 16. The side sills, end cross ice members, cross ties and stringers are arranged in the underframe in the conventional manner.

The center sill 8 is made up of a pair of inverted T sections 18 each having an elongated vertical .web 20 and horizontal flanges 22 extending from opposite sides of the bottom of the web. The T sections 18 are arranged with the webs in spaced parallel relation and the flanges 22 lying in a common horizontal plane. A center sill top cover plate 24 spans and is welded to the tops of each of the webs 20 with the edge portions thereof overhanging the webs to form ledges 26. The top cover plate 24 is welded to the tops of each of the webs 20 preferably 'by two lines of welding as at 28 and 30.

The overhanging ledges 26 of the center sill cover plate 24 serve a twofold purpose. In forming ,the center sill, the cover plate 24 is placed on a'flat surface and the T sections are positioned on the plate with the tops of the webs 20 resting on the plate 24 in the desired position. The'T sections are then welded to the plate by a weld along each side of each of the webs 20 as at 28 and 30. t

' of the center sill 8 to one of the side sills 4. Although I have shown one vertical plate 32 on each side of the center sill, it will be noted that a pair of spaced parallel plates 32 on each side of the center sill may be used, if desired. The inner end 34 of the vertical bolster plate 32 abuts and is welded to the webs 20, as best shown in Figure 2. The bottoms of the inner ends 34 rest upon and are welded to the flanges 22. The top edges of the vertical bolster plates 32 are flush with the tops of the webs 20 and support a connecting bolster top cover plate 36 which is welded to the tops of the plates 32 and extends transversely from one side sill 4 to the other. The center sill cover plate 24 is cut away at the point of junction with each bolster so that the connectingtop cover plate 36 may span and be welded to the tops of the webs 29 and the adjacent ends of the center sill cover plate 24. Thus an integral and flush center sill and bolster assembly is formed. A bolster bottom cover plate 38, which is welded to the bottoms of the vertical bolster plates 'on each side of the center sill may be provided on the underside of each bolster. The inner end 40 of each of the bolster bottom cover plates abuts flush with and is welded ward flange 22 of the center sill. The notched portion of 7 each plate 42 is welded to the flange upon which it rests.

A cross bearer bottom cover plate 48 extends along and is welded to the bottoms of the vertical cross bearer plates 42 and the center sill. The-center sill top cover plate 24 is cut out at the point of junction with each pair of oppositely disposed vertical cross bearer plates 42 to accommodate a transversely extending cross bearer top cover plate 50 which extends along and is welded to the top edges of the vertical plates 42. The cross bearer top cover plate 50 spans and is welded to the tops of the center sill webs 20 as well as being butt welded to the adjacent ends of the center sill cover plate 24.

I have found it preferable to form the T sections 18 from an H beam rolled with flanges having a Width equal to the width of the flanges desired for the bottom of the center sill to be formed and an inside depth slightly greater than twice the depth of the T sections desired. The web of the H beam is cut to form two T sections by gas burning with two adjustably spaced burners; The depths welded to the bottom of each of-said vertical bolster of the T sections formed is positively and accurately controlled, notwithstanding variations in the inside depth of the H beam due to roll wear or other causes, by properly adjusting the burners so that the distance between each burner and a flange of the H beam is equal to the depth of the T section desired. This is illustrated graphically in Figure 4.

While one embodiment of my invention has. been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim: 7 I

1. In a car underframe, a center sill extending longitudinally of the car,a bolster extending transversely from opposite sides of said sill adjacent each end thereof, said center sill being comprised of a pair of inverted T sections each having a vertical web and horizontal flanges extending from opposite sides of the Web, :said pair of inverted T sections being disposed with the webs in spaced parallel relation and the flanges in a common horizontal plane, said webs forming the web of said sill and said flanges forming the flange of said sill, each of said bolsters including at least one vertical bolster plate extending transversely-from each side of said sill, the inner end of each of said plates abutting and being welded to the web of said sill, the bottoms of said inner ends resting on and welded to the flange of the sill, the top edges of said plates being flush with the top of the web of the sill, a transversely extending bolster top cover plate welded to the tops of said vertical bolster plates and the top of the sill, a transverse bottom cover plate welded to the connecting top cover plates of the bolsters,

' and a sill top cover plate spanning and welded to the top of said sill and extending longitudinally from each. bolster to the end of the sill, said last mentioned cover plates abutting and welded at their inner ends to respective bolster connecting top cover plates.

2. In a car underframe as defined by claim 1 characterized by a pair of spaced cross bearers extending transversely from opposite sides of said sill, each of said cross bearers including a vertical cross bearer plate extending from opposite sides of said center sill, a cross bearer connecting top cover plate welded to the tops of and extending longitudinally of each pair of oppositely disposed vertical cross bearer plates,tthe sill top'cover plate being cut away at the points of junction with said oppositely disposed vertical cross bearer plates, each of said cross bearer connecting top cover plates spanning said sill flush with the adjacent ends of the sill top cover plate, each of said cross bearer connectingtop cover plates being welded to the sill and to the sill cover plate.

References Cited in the file of this patent