US1828002A - Railway truck centering device - Google Patents

Description

Oct. 20, 1931. J. c. TRAVILLA, JR 1,328,002

RAILWAY TRUCK CENTERING DEVICE 2 SheetsSheet l Filed Feb. 2. 1931 Oct. 20, 1931. J. TRAVILLA, JR 1,828,002.

RAILWAY muck CENTERING DEVICE Filed Feb. 2. 1931 zsneets-sheen 2 MVen/or A ffornfg M/WIJC7/ZYM/a, 1:

wa 2c, 1931 umreo s'r firas- PATENT -O FF C JAMES O. TRAVJILA, m, PHILADELPHIA, PEHNSYLVANiA, ASSIGHOR T0 GENERAL I STEEL OASTIN'GS COBZPOBATION,'OF GRANITE CITY, ILIINOIS, OOBPOMTIOH OI nnnawm mnwnr rnucx cnn'rname nnvron n application fled Iebruary 2,- 1981. Serial 11o. 518,038.

My invention relates to railway rolling stock and consists particularly in a novel r enewable rocker centering device for use n locomotives, tenders, 'and other railway I vehicles.- 1.

It is at present customary in railroad practice to equip engine trucks with fioatlng or laterally movable bolsters and rocker bearings for the purpose of reducing the wear on m the driving'wheel flangesand the strain on the frame when the locomotive is moving around a curve. Various types of rocker bearings hav been developed in which the degree of resistance to lateral movement of the bolster, determined with reference to the vertical load remains constant. Somedlfliculty has been met, however, especially 1n high speed electric locomotives, in providing a sufiicie'ntly high initial resistance to maintain the proper stability when the locomotive is running on straight or slightly curved track at l u h speed, while, at the same time, providing or a low resistance when the 1000'- motive is running at low speeds on a sharp curve in the railroad ards.

The main object o my present invention is to construct a rocker centering device which will overcome these difiiculties. I attain this general object and others, later appearing, in the structure illustrated in the accompanying drawings in which- Figure 1 is a vertical transverse section taken on the transverse center line of a locomotive truck embodying my invention.

Figure 2 is a vertical longitudinal section taken on the longitudinal center line of the same.

Figure 3 is a top view showing one of the rockers. Y

Fi ures 4, 5 and 6 are detail views corresponding with Figure 1 and showing successive positions of the rocker as the bolster moves laterall of the frame.

The truck mine is of familiar construction and includes box-shaped side members 1 tied together at each end by transverse members 2, and intermediate transoms 3 having connecting yokes 6 depending therebetween. The frame is carried on the journals by .any suitable spring equalizer system includ-ing equalizer'bars shown in Figure 1.

The load from the locomotive is carried directly upon a center bearing 7 formed integrally with ,swing bolster 8 which is supported from the yokes 6 through a rocker centering device to be described later. The bolster is free to move laterally between transoms 3 which serve as guides. All ofthe structure above mentioned, except the rocker centering device, is similar to that described in Patent No. 1,060,222, issued toW. E. Woodard, April 29, 1913. i v

The rockers are counte arts and each is composed of an III-shaped ody' portion 11, end cams 14, and segmental journals12 and. 13 which normally rest within arcuate depressions 15 formed in a renewable rocker seat 9 provided on gokefi. Each rocker cam surface is de'scribe upon the same center as the bearin%surface of the opposite segmental journal. olster 8 has curved bearings 16 on its lower surface, each of which restson the convex upper surface of the corresponding end cam 14. Links 19 and 20 are each pinned at one end to a lu 18 depending rom the center plate portlon of bolster '8 and at the other end secured to lugs 17 extending upwardly from the body portions of the rockers. These links hold the rockers in fixed relation-to each other when the bolster moves laterally and irrespective of slip page which might otherwise occur between the bolster and the rockers.

The curvature of the lower surfaces of the bearings 16 are preferably identical, as are the upper convex edges of cams 14, and each bearing surface includes a central concave portion, that is, a portion of increasing slope of curvature, and outer portions of decreasing slope at each side thereof. The rockers and bearings are so arranged as to offer a.

high resistance to initial lateral movement tion. The relative resistances at bolster dis-.

placements of one inch, three inches, and six inches from the normal rest position shown in Figure 1 are indicated graphically in Figures 4, 5' and 6 by the distances as, y and 2 which are the horizontal components of the turning moments in each case. The resistance at rest is 35% of theload; at a displacement of one inch, 40%; at three inches, 25% and at six inches 10%. i This arrangement provides a high resistance when the locomotive is traveling on straight track at high speeds and a low resistance when traveling on sharp curves in the yards.- The low resistance will reduce the flange wear on the wheels. The theoretical desired resistance when the locomotive is on a straight track would be a greater resistance than the desired resistance when the locomotive is on a curve. However, since the friction for starting lateral displacement is very high, the device is designed for an initial resistance less than that attained after a slight displacement.

The essential features of the invention may also be embodied in a rocker centering device for connecting the locomotive underframe type in which there is no swinging bolster and each rocker cam would constitute a separate element. Moreover, the device might be modified for application to' any two vehicle frame memberscapable of relative lateral movement and varied as to various details without departing from the spirit of the invention and I contemplate the exclusive use of all such variations as come within the scope of my claims.

I claim- 1. A rocker centering device for railway vehicles comprising a rocker and a rocker bearing mounted respectively on vehicle members capable of relative lateral movement, said bearing being inclined downwardly and outwardly on each side of the center thereof, the inclinations being steeper near the center of the bearing than near the outer ends thereof.

2. In a railway truck, the combination of a frame, a bolster adapted to move laterally relative thereto, and a rocker supporting said 60 bolster from said frame, there being a bearing on said bolster for engagement with said rocker and having a surface inclined downwardly and outwardly on each side of the transverse center line of the bearing, the inclinations being steeper near the center of faces and convex side portions approaching" the horizontal near the ends thereof.

4. A rocker centering device for railway with a leading or trailing truck of the radial the bearing than near the outerends thereof.

concave central portion and outer portions of a high resistance to the initial lateral displacement of said members, a slightly higher resistance after a small lateral displacement, and a comparatively low resistance after additional displacement. l

6. A rocker centering device for railway vehicles comprising a rocker and a rocker decreasing slope at each side thereof, and said rocker and bearing being arranged to ofier bearing mounted respectively on vehicle members capable of relative lateral movement, the bearing surfaceof said rocker being convex and the engaging surface of said bearing being curved "and including a central concave portion and an outer portion of decreasing slope. u

7. A rocker centering device for railway vehicles comprising a rocker and a rocker bearing mounted respectively on vehicle members capable of relative lateral move ment, the bearing surface of said rocker being convex and the engaging surface of said bearing being curved and'including a central concave portion and an outer portion of decreasing slope, and said device being arranged to ofler increasing resistance during initial relative displacement of said members and decreasing resistance after a certain.

point has been reached.

8. In a railway truck, the combination of a frame, a bolster adapted to move laterally relative thereto,-and a rocker supporting said bolster from said frame, said rocker and bolster engaging along curved surfaces, theengaging surface of saidbolster including a concave central portion and portions of decreasing slope at each side thereof, and said rocker and the engaging surface of said bolster cooperating to offer a high resistance after a small lateral displacement of said bolster, and a comparatively low resistance after additional displacement thereof.

9. In a railway truck, the combination of a frame, a bolster adapted to move laterally thereto, and a rocker supporting said bolster from said frame, said rocker and bolster engaging along curved surfaces, the engaging surface of said bolster including a central concave portion and outer portions of decreasing slope, and said rocker and the 'engaging surface of said bolster cooperating to ofier a resistance to initial lateral movement of said bolster of approximately 35% of the load thereon, a. resistance of approximately 40% of the load after a small lateral movement of said bolster, and a resistance of approximately 10% of the load near the extreme lateral movement of said bolster.

In testimony whereof I hereunto afiix my signature this 27th dag of J anufi, 1931-. JAMES TRAVI A, JR. I

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