摘要 |
<p>Case 5781 RAILROAD CAR TRUCK A railroad car truck includes a pair of spaced side frames carrying therebetween a transversely positioned bolster. Ends of the bolster are positioned within a window formed in each side frame. A connection between the side frame and bolster includes an interposed set of springs which cushions vertical movements of the bolster. These movements are dampened by sets of friction shoes which interact with wear surfaces formed as part of the bolster and side frame. The bolster-side frame connection also accommodates pitching and yawing movements of the bolster and pitching movements of the side frames. These rotational movements are not cushioned and can produce substantial stresses when contact occurs between abutting structural members of the bolster and the side frames. To maintain such stresses below the yield point of the structural members, bolster-side frame contact is restricted to areas of the bolster where the stresses may be distributed to members having sufficient strength.</p> |