US1931620A

US1931620A - Car truck bolster

Info

Publication number: US1931620A
Application number: US490772A
Authority: US
Inventors: Percy W Ott
Original assignee: Buckeye Steel Castings Co
Current assignee: Buckeye Steel Castings Co
Priority date: 1930-10-23
Filing date: 1930-10-23
Publication date: 1933-10-24
Anticipated expiration: 1950-10-24

Description

.Oct 24, 1933. P. w. OTT

CAR TRUCK BoLsTER Filed oct. 23, 1930 2 sheets-sheet 2 a n h/ 9 i Patented ocr. 24, 1933 UNITED? STATES PATENT oer 1,931,620 can `TRUCK BoLs'rEa Percy W. Ott, Columbus, Ohio, assigner to The Buckeye Steel Castings Company, Columbus,

Ohio

Application October 23,

, 12 Claims.

This invention relates improvements in car truck bolsters.

Truck bolstersfor railway cars are usually calculated in accordance with the exure theory for 5 simple beams, but owing to thefact that these bolsters are made deeper at the central portion than at the ends, and also to the relatively thin, boxlike section, as well as to the practical necessity ot placing holes in the walls for inspection, assembling, and holding in place the cores used in the ,manufacturing process;v the completed bolster, in test or service, does not behave in accordance with the design theory, but rather in accordance with the action of a cambered 5 truss. That is, the top andv bottom walls are the bolster, and so to distribute the material of the bolster that the stresses resulting from vertical loads may take their natural paths through elements or members properly proportioned and without setting up unduly large secondary stresses. At the same time, consideration is given to the Afact that the bolster must resist side forces, and acts, laterally, as a simple beam, due to the relative straightness of the sides..

With the foregoing object outlined and with. 35 other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, .and 1more particularly. pointed out in the appended claims.

In ythe drawings,

Figf is a side elevation of one-half of one form o1' bolster constructed in accordance with the invention. l

Fig. 2 is atop plan view of the same.

Fig. 3 is an elevation of the other half of a Aruoded iorm of the bolster.

Fig. 4 is a bottom plan view of in Fis. 3.

Fig. 5 isa transverse vertical sectional view ontheline5-5ofFig.1-. f

Placisasimilarviewontheline-fof F18. 3.

It will be understood that the other half of the form shown "ss'the bolster snownmriga. iandz aexactly the 1930. Serial No. 499,'Zl2

(Cl. MI5-230) In each form of the invention, the bolster is a metal casting of transverse bos section throughout substantially its entire length.

Referring to Figs. l and f?, the bolster has uri-s broken side Walls a bottom la which is liori zontal at the ends ofthe holster, and of how@ y shape'as shown at lh between the end port tions'la.

The top of the bolster is horizontal at the ends, as shown at lc, and then stepped upwardly to provide a side bearing 9 and an upwardly inclined portionv 9a, which merges into the `flat medial portion 9b.

The top, bottom and side Walls or" the en1bodi ment shown in Figs. 3 to t inclusive are the same in conjiguration as those illustrated in Figs. i and 2.

In each form o the invention, the side walls l, which function as web plates Under the action of vertical loads on the bolster, and as tension or compression elements under the action of c 'lateral forces, are made, as nearly as practicable,

complete, unbroken plates.

Within the bolster, a central system 2 extends throughout its length and acts only as a web member under vertical load, and this system is made as a truss or lattice girder, continuous end to end, except for certain missing elements, referred to and explained hereinafter.

The usual center post construction is omitted,

and the center plate 3 is reinforced and stifi'ened by two internal longitudinally extending flanges or ribs l` placed under it, which flanges sustain and are connected together by a bridge 5 formH lng the king-pin pocket. At the ends oi' these danses are positioned two of the members c or nearly as practicable, .tree from holes or inter ruptions.

Under the center plate, the diagonal bracing of the central truss system is omitted for purpose or lightening the structure, since the shear in the panel is sere when the load een trally located. When the load. is partially or wholly on a side bearing 9, the shear in this panel is small, and in order that it may be properly transferred to the side walls,4 the top and bottom plates of the bolster are laterally stiliened. For instance, at the top there is a heavy upstanding ring `around the center plate, serving as a stiener. At the bottom, the stiiening may be made by flaring outwardly from each compression member 6, lateral stiiening flanges 11, as best shown in Figs. 4 and 5. Further lateral stiffening may be accomplished by widening at this point, the bead or internal flange 12 around the lightening hole 12a adjacent to the lower end of the compression member.

Diagonal bracing members or struts 8 may extend upwardly from the lower ends of the members 6 to the top of the bolster, as shown in Fig. 3, but for the purpose of lightening the structure and also for ease in manufacture, such diagonal bracing may be omitted, as in Fig. 1. At any rate, the shear in these panels is small, due to the slopes of the top and bottom at these points, and the consequent non-horizontal action of the compressions and tensions therein. At the outer ends of these panels also, provision is made for a lateral stiffening of the top and bottom of the bolster. At the bottom, this may be done as shown in Fig. 4, by widening or flaring the bead around the hole 12a as at 14 in the bottom under the panel. At the top, the side bearing pad 9 which extends entirely across the bolster, and is thickened, is made to serve as a lateral stiiener.

`lines from joint to joint.

Outwardly from these panels, the latticed trussed central system extends unbrokenly to the ends of the bolster as at 18 in Figs. l Iand 2, and 18a in Figs. 3 and 4, and at this point, it will be noted that the lattice work at 18 is slightly diierent from that at 18a. In both forms, the struts which make up the part 18, 18a, generally intersect at points where the end spring loads are normally applied, and at points where the top and bottom of the bolster change curvature.

Between the points of juncture of the central latticed system, the top and bottom of the bolster, serving as chords of a truss, are simple compression and tension members, and as such, have their neutral axes extending in straight For this purpose, and to retain the desirable curved outline and avoid sudden changes of curvature, (which are undesirable from a manufacturing standpoint), the beads or anges around the lightening holes in the top and bottom are disposed in a novel manner to counter-act the bending effect usually apparent at these points when the bolster is excessively loaded. As will be noted, each-

bead

12 and 13 is of essentially equal area at all cross sections, the bottom bead 12 being high and narrow opposite the central portion of the hole 12a and decreasing in height and flaring outward toward the ends of the hole, while the top bead 13 of the hole 13a is just the reverse. The top beads, instead of being carried around the ends of the holes 13a, are merged into the compression members of the central truss system, while the bottom beads are flared at the ends to produce a lateral stifening of the bottom of the girder, as previously referred to.

Further, to counter-act the usual tendency of the top wall to cave inwardly under excessive loading, the central portion of the top is extended horizontally outward for a considerable distance beyond the inner ends of the top lightening holes, as shown at 15, and these portions are stabilized by arranging substantially trianguiar ribs 16 between the beads 13 and compression members 6.

Both forms of the invention have vertical compression posts 17 in Figs. 1 and 2, and 17a. in Figs. 3 and 4. These posts form part of the central lattice system, and in each instance, a post is arranged directly under the side bearing pad 9. Each post is of hollow halfy cylindrical shape, open toward the medial portion of the bolster. This construction admits of its being properly placed with respect to the loads on and the curvature of the bolster, at the same time giving access to a central rivet hole 17h for the side bearing casting, (not shown), as well as arranging for its convenient merging at the upper end with the `bead 13 which extends around the top lightening hole.

The advantage of such designs rests mainly in economy of material for by distributing the metal in the manner disclosed, agiven load can be carried by a lighter weight bolster member than with the conventional metal distribution.

While I have disclosed what I now consider to be preferred embodiments of the invention in such manner that the same may be readily understood by those skilled in the art, I am aware that changes may be made in the details disclosed, without departing from the spirit of the invention, as expressed in the claims.

What I claim and desire to secure by Letters Patent is:

l. A car truck bolster having a box section throughout substantially its entire length and provided interiorly with a vertically disposed central latticed system, substantially continuous from end to end of the bolster, most of the members of said system being diagonally arranged.

2. A hollow car truck bolster having a box cross section throughout its entire length and reinforced internally by a central truss system, said system being made up mainly of inclined struts, the medial portion of the top of the bolster being horizontally disposed and provided with an upstanding circular bead, said horizontal portion extending outwardly for some distance from the bead toward the ends of the bolster.

3. In a car truck bolster having a box cross section, a top having an opening to reduce weight, a bead extending around said opening, the medial portions of the bead being widened transversely of the bolster, and the end portions of the bead being deepened vertically.

4. A car truck bolster having a top plate and a bottom plate, one of said plates having an opening for reducing weight, a bead extending about the opening, the sides of the bead having their medial portions widened transversely of the bolster, andthe end portions of the bead being gradually deepened away from the .medial portion of the opening.

5. A car truck bolster having a top plate and a bottom plate, one of said plates having an opening therein for the reduction of weight, a bead extending about said opening, the medial portions of the sides of the bead being reduced in thickness, and the end portions of the bead being gradually widened in directions away from the medial portions of the bead.

6. A car truck bolster of hollow form and of` box-shaped cross section throughout substantially its entire length, downwardly diverging compression members joining the top and bottom of the bolster, side bearings at the top of the bolster, and diagonal struts extending upwardly from the lower ends of the compression members to said side bearings.

'7. A car truck bolster of hollow form and provided at its top with side bearings, posts beneath the bearings and extending from the bottom to the top of the bolster, and a centrally disposed truss extending from each post to the end of the bolster, each truss comprising a plurality of inclined elements.

8. A car truck bolster of hollow form provided with an internal inclined compression member extending from the bottom to the top of the bolster, said member having laterally extending wings at its lower end merging into the bottom of the bolster.

9. A car truck bolster of hollow form, provided nteriorly with a channel-shaped compression member extending from the top to the bottom of the bolster, and lateral wings at the lower end of the compression member joining the sides of the latter to the bottom of the bolster.

10. A car truck bolster of hollow form, having a center plate at its top, downwardly diverging channel-shaped compression members joining the central plate to the bottom of the bolster, the top of the bolster and the bottom of the bolster having openings for reducing weight, arranged between said compression members and the ends of the bolster, channel-shaped vertical posts joining the top and bottom of the bolster and arranged between the openings and the ends of the bolster, and beads extending along each of the openings and having their ends merging into the compression members and posts.

1l. A car truck bolster of hollow form, having a center plate at its top, downwardly diverging channel-shaped compression members joining the central plate to the bottom of the bolster, the top of the bolster and the bottom of the bolster having openings for reducing weight, arranged between said compression members and the ends of the bolster, channel-shaped vertical posts joining the top and bottom of the bolster and arranged between the openings and the ends of the bolster, and beads extending along each of the openings and having their ends merging into the compression members and posts, the bead of one of said openings being widened at its end portions.

12. A car truck bolster of hollow form, having a center plate at its top, downwardly diverging channel-shaped compression members joining the central plate to the bottom of the bolster, the top of the bolster and the bottom of the bolster having openings for reducing weight, arranged between said compression members and the ends of the bolster, channel-shaped vertical posts joining the top and bottom of the bolster and arranged between the openings and the ends of the bolster, and beads extending along each of the openings and having their ends merging into the compression members and posts, the bead along one of said openings being widened at its medial portions.

PERCY W. O'I'I.