US2495570A - Truck arrangement - Google Patents

Description

Jan... WW R B. COTTRELL TRUCK ARRANGEMENT Filed Jan. 12, 1945 l l I II I i I +34 i i r 1 m L 13 L2! 'INVENTOR. ioadz'. ZQZfZf/JZ [Z atented Jan. 24, 1950 TRUCK ARRANGEMENT Robert B. Cottrell, Chicago, 111., assignor to American Steel Foundries, Chicago, 111., a corporation of New Jersey Application January 12, 1945, Serial No. 572,453

3 Claims. I

My invention relates to railway car trucks and more particularly to a truck of the type having snubbing means mounted in the ends of the bolster for engagement with the adjacent side frame columns.

The present invention is directed primarily to an improvement over the type of truck described and illustrated in a co-pending application, Serial No. 436,731, filed March 30, 1942, in the name of David M. Light, which application has matured to Patent No. 2,378,414 dated June 19, 1945. The said application illustrates a truck such as described wherein friction shoes are mounted in each side of each bolster end and are slidably engaged with diagonal walls of the bolster end in such manner as to maintain the friction shoes in engagement with the adjacent side frame columns during movements of the bolster longitudinally of the truck.

A more specific object of my invention is to devise such a car truck as that described wherein the friction shoes are so mounted in the bolster as to freely accommodate'such described movement of the bolster without causing misalignment of the engaged surfaces of the friction shoe and the side frame column.

A different object of my invention is to provide within the pockets of a bolster end friction shoes and actuating springs of novel form therefor formed and arranged to permit movement of the shoes laterally of the bolster while maintaining the friction face of each shoe in full engagement with the adjacent side frame column.

In the drawings,

Figure 1 is a fragmentary sectional view of a railway car truck embodying my invention, the section being taken in a longitudinal vertical plane bisecting the truck substantially as indicated by the line l! of Figure 2, only one end of the truck being shown inasmuch as it is similar at opposite ends thereof.

Figure 2 is a, view taken in the transverse horizontal plane indicated by the line 2-2 of Figure 1 with the bolster end being shown in top plan car truck shown in Figure 3, the section being taken substantially in the plane as indicated by the line 4-4 of Figure 3.

Describing my invention in detail and referring first to the modification shown in Figures l and '2,

the truck is substantially identical with that illustrated and described in said co-pending application. The side frame comprises a compressionmember 2 and tension member 4 merging adjacent each end of the truck with a column 6 defining with said members a bolster opening 8. The tension member 4 beneath the bolster open-' ing is of well known form comprising a box-section with the top chord ll) thereof widened and formed at each of the inboard and outboard side's thereof with an upstanding flange l2 affording convenient confining means for the lower ends of the bolster-supporting springs l4, l4 seated as at l6 upon the top chord ll] of the tension member.

Each column 6 is of U-section as illustrated in Figure 2, comprising the inboard and outboard legs I8 and connected by the transverse wall 22, said legs presenting respectively parallel inboard and outboard guide surfaces 24 and 26 for cooperation with the adjacent guide lugs 28 ofthe bolster generally designated 30, said bolster being seated at 32 upon the springs I 4', l4.

The bolster is of box section and comprises the top and bottom walls 34 and 36, as well as the spaced side walls 38 and the intermediate transverse wall 39 parallel with said side walls. Pockets 40, 40 are formed at opposite sides of the bolster, and each of said pockets is defined by the top wall 34, a rear wall 42, and spaced outboardand inboard vertical walls 44 and 46. At opposite sides of each pocket are ledges formed by diagonally arranged inboard and outboard walls 48,"

and 50. Each pocket 40 receives therewithinafriction shoe generally designated 52 frictionally: engaged as at 54 with the adjacent wear plate 56 secured to the wall 22 of the column. Each shoe 52- comprises front and rear walls 58 and 60 and: also comprises a bottom wall 62 affording a seat for the coil spring 64 extending between the diag-. onal walls 48 and in the associated pocket and seated at its upper end as at 66 against the wall 34 defining the top of the pocket. The shoe also comprises the side walls 68 and H! presenting at I. the bottom thereof diagonally arranged crowned friction faces in complementary engagement as at l2 with the diagonal walls 48 and 5B of the? pocket.

In the modification illustrated in Figures 1, and 2, the coil spring I54 is of conical form with the end coil 14 forming the apex .of the springseated against the top wall 34 of the bolster and the end coil-l6 forming the base of the spring seated on the horizontal wall 62 of the shoe, said spring being under compression between said walls. During movements of the bolster longitudinally of the truck, each shoe will move into and out of the pockets in the bolster and it will be apparent that during such movement of the shoe, the end coil 14 will not move and, therefore, will be maintained in its initial position on the top wall 34 of the bolster and the end coil 16 will move with the shoe laterally of the bolster. In explanation, due to the progressively diminishing dimeters of the convolutions of the spring from the base to th apex of the spring, resistance of the coils to lateral movement will also progressively diminish from the lower coils to the upper coils of the spring, and accordingly, a substantially greater lateral displacement will occur in the lower coils than in the upper coils which will decrease sufliciently as it approaches the upper coils to be nullified by the frictional resistance of the end coil 14 against the top wall of the bolster. Thus it will be apparent that my novel form of spring will permit free lateral movement of the shoe withoutv tilting of the shoe which might otherwise occur under certain conditions where a conventional spring of uniform diameter is used, as in the latter case, lateral movement of the shoe may be considerably restricted due to the substantially uniform resistance offered by the spring throughout its length to lateral movementv due to the frictional engagement of the upper end of the spring with the bolster top wall restricting th lateral displacement of the lower end of the spring seated on the shoe which may be sufiicient to prevent the friction surface of the shoe from having full engagement with the adjacent column wear plate.

It will be understood by those skilled in the art that for a given friction value at 54 (Fi ure 2) which affords proper damping of vertical bolster oscillations with the bolster in normal position equidistantly spaced between the columns, it is desirable to offer maximum resistance to horizontal bolster oscillations between the columns and at the same time provide a spring 04 which operates under minimum stress concentration in view of the space limitations inherent in this type of device. This is achieved in the preferred embodiment of Figures 1 and 2 by tapering the spring 64 from a normal diameter at its lower end, whereby normal resistance is offered to low value impacts tending to produce horizontal bolster oscillations and great.- er resistance is offered to impacts of greater value inasmuch as the lower portions of the spring, because of the larger diameter of the coils and therefore lower capacity, are com-1 pressed by impacts of low value and the smaller diameter or higher capacity portions of the spring are compressed by impacts of high value and afford a relatively great resistance thereto. Thus it will be understood that the tapered spring 64 afiords the same resistance to horizontal bolster oscillations afforded by a conventional spring of uniform diameter and affords greater resistance to relatively great impacts than that afforded by a conventional spring. Furthermore, high stress concentration is avoided by utilizing the maximum space available at the lower end of the spring. In addition, any tilting of the bolster or rocking of the shoe will not abrade the sides of the spring since the outer surface of the spring recedes upwardly from the surrounding portions of the shoe. This feature prolongs the life of the spring considerably since even a slight marring of the spring surface may quickly de- 4 velop into a fracture. Also, on wearing of the friction wall 58 of the shoe, the rear wall 60 of the shoe, which will move toward the spring, will not abut thereagainst.

A further modification of my invention is shown in Figures 3 and 4 and in this modification the side frame and bolster construction are fragmentarily shown inasmuch as they are identical with the bolster and side frame shown in the previous modification, the side frame being shown with the column in section and comprising the inboard wall I02 and the transverse wall I04, said wall I04 having secured thereto the wear plate 106 in frictional engagement as at I08 with the front wall IIO of the friction shoe H2. Th friction shoe H2 is similar to the shoe described in the previous modification and is received within each pocket H4 and is seated against the diagonal walls IIB of the pocket and actuated into engagement with the adjacent wear plate I06 bya coil spring I20 extending between the diagonal walls IIIi of the pocket and seated as at I22 on the bottom wall I24 of the shoe and as at I26 against the top wall [28 of the bolster. As in the previous modification, the spring I20 is formed and arranged for a similar purpose and is of uniform diameter with the upper end formed as an annular bar or pivot member I 30 frictionally engaging the bolster wall I28 and extending across the longitudinal axis of the spring so that the same will not only form a pivot about which the spring may rotate but will satisfactorily impart the reaction of the spring against the bolster wall I28 to the associated shoe. It may be noted that the bar I30 is positioned longitudinally of the bolster on the bolster wall I28 with the end coil of the spring seated at I22 on the horizontal wall I2 3 of the shoe, and it will be apparent that the engagement of the bar I30 of the spring will form a rocker whereby, during movement of the shoe along the diagonal walls of the bolster, the spring will rock about the pivot provided by the bar I30 so that the end of the spring seated on the friction shoe will move laterally therewith in the bolster pocket with minimum distortion of the spring and consequently free lateral movement of the shoe whereby the friction face of the shoe will be maintained in full engagement with the wear plate on the adjacent column. It may be noted that due to the fact that the bar I30 of the spring, pivotally and frictionally engaging the bolster wall I28, extends transversely across the longitudinal axis of the spring, the bar will be maintained in its original location on the bolster wall during movement of the opposite end of the spring with the shoe laterally of the bolster without diversion of the path of force of the spring to the shoe.

It is to be understood that I do not wish to b limited by the exact embodiments of the device shown which are merely by way of illustration and not limitation as various and other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

1. In a railway car truck, a side frame comprising spaced columns and an intervening bolsteropening, a bolster end resiliently supported on said frame in said opening, a pocket in each side of said bolster end, said pocket comprising a top wall and spaced flat diagonal surfaces facing an adjacent column, a friction shoe in said pocket comprising a bottom wall spaced from said top wall and spaced crowned wedge faces in slidable engagement with said diagonal surfaces, said shoe having a substantially vertical friction wall in frictional engagement with the adjacent column, and a substantially vertical coil spring extending between said diagonal surfaces and having the upper end thereof bearing against said top wall and the lower end thereof bearing against said bottom wall and being operative to urge said shoe along said diagonal surfaces and thus said friction wall of the shoe into said frictional engagement with the adjacent column, said spring being of conical form and presenting an outer surface sloping upwardly away from said front wall to afford a clearance therefor upon rocking movement of said shoe or lateral movement of said shoe along said surfaces toward said spring.

2. In a railway car truck, a pair of relatively movable members, one of said members having a friction surface and the other of said members having wedge surfaces sloping toward said friction surface, a friction shoe housed in said last-named member and having surfaces in engagement with said wedge surfaces and friction surface, and a coil spring extending between all of said surfaces and compressed between a wall of said last-named member and a wall of said shoe, said spring being formed to provide a smaller seat therefor against said member wall and a larger seat against said shoe wall, the coils of said spring receding from the portion of said shoe engaging said friction surface as they approach said member wall.

3. In a railway car truck, a side frame, a bolster spring-supported therefrom, a friction face on said frame, spaced wedge surfaces on said bolster sloping toward said face, a friction shoe of cuplike form comprising spaced substantially vertical front and rear walls, spaced side walls in wedge engagement with said wedge surfaces and interconnecting said front and rear walls, a web extending between said front and rear walls, spring means of conical'form extending between said Walls and having the apex thereof seated against a wall on said bolster and the base thereof seated against said web, the sides of said spring means receding from said shoe walls in a direction away from said web to accommodate various movements of said shoe along said wedge surfaces to prevent engagement between any of the shoe walls and said sides of said spring means.

ROBERT B. COT'IRELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number, Name Date 1,080,979 Kanane Dec. 9, 1913 1,631,079 Wellman May 31, 1927 1,851,973 Brandt Apr. 5, 1932 1,916,152 Hedgcock June 27, 1933 2,053,989 Goodwin Sept. 8, 1936 2,159,138 Duryea May 23, 1939 2,347,463 Couch Apr. 25, 1944 2,366,957 Cottrell Jan. 9, 1945 2,378,415 Light June 19, 1945 2,407,950 Cottrell Sept. 17, 1946

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