US2206487A - Railway car truck - Google Patents

Description

y 1940- I E. P. o'coNNoiQ 2,206,487

RAILWAY CAR TRUCK Filed March 15, 1939 INVENTOR ATTORN Y Patented July 2, 1940 iJNlTED s'r rss RAILWAY GAR TRUCK Edward P. OConnor, Pittsburg, Kans., assignor of one-third toJohn S. Lemley, St. Louis, Mo., and one-third to William N. Nelson, Pittsburg,

Kans.

Application March 15, 1939, Serial No. 262,000

1 Claim.

My invention relates torailway car trucks and more particularly to a truck provided with novel means of resiliently supporting the load to be carried thereby.

This invention is an improvement over that shown in my Patent 2,110,004, bearing date March 1, 1938. p

In the railway car trucks of the known art, the bolsters are mounted upon a nest of springs, usually a group of four at each spring plank, or alternatively upon elliptical springs. These springs are compressed under load and shock and recoil with approximately a force equal and opposite to that which caused them to be compressed. This recoil results in periodic oscillations and vibrations which depend upon the speed, the load, the wheel and track conditions. These oscillations will pass through many cycles before the car returns to its normal riding plane.

Excessive shocks due to spring recoil are transmitted to the car body and have been known to cause damage to the load, to the cars and to the track. Then, too, the oscillations resulting from excessive spring recoil cause rocking and bouncing which tend to permit the wheels to leave the rails, thus presenting a danger of derailment. The diniculties above mentioned are not eliminated by increasing the spring capacity. Numerous attempts have been made to counteract this known condition by the use of snubbers, shock absorbers and damping springs which are intended to break up the undesirable harmonic motions.

In my Patent 2,110,004, I have shown one spring construction in which periodic oscillations and vibrations are dampened. In my previous construction, the cam members are formed along surfaces lying in a single plane. I have found that there is a tendency for the cams to move laterally with respect to the followers.

One object of this invention is to provide a construction in which lateral motion of the cams with respect to the followers is obviated.

In the accompanying drawing which forms part of the instant specification and is to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views;

Figure 1 is a fragmentary elevation with parts in section, of a railway cam truck equipped with one embodiment of my invention.

Figure 2 is an end elevation of the spring, cam and follower assembly with a portion of the upper follower broken away.

Figure 3 is a side elevation of the spring, cam

and follower assembly shown in Figure 2, with parts in section.

Figure 4 is a sectional view, taken along the line 4-4 of Figure 3.

Figure 5 is a plan view of one of the follower members, showing the surfaces with which the cams coact.

In general, my invention contemplates the use of a pair of cams forced outwardly by springs whose axes are at right angles to the thrust whereby friction to movement of the cam surfaces will act as a damping force, in which the cams are formed with surfaces lying along planes forming angles with each other.

More particularly, referring now to the drawing, the wheels I support the customary axles 2, upon which are mounted spring planks 3. The spring planks carry a channel member 24 and support the spring assemblies of my invention. The spring assemblies support the usual truck bolster 4, which, in turn, supports the railway car body.

The spring assembly comprises a lower follower member 5 and a like upper member 6.

Referring now to Figure 5, it will be seen that the follower member is provided with a surface I, inclined with respect to the horizontal and also inclined with respect to surface 7 which is likewise inclined to the horizontal. The surfaces I and 1' meet along the line Ia and form a v. Similarly inclined surface 8 extends along a plane which forms an angle with the plane of inclined surface 8'. The cam members II and M are formed with correspondingly inclined surfaces adapted to coact with the inclined surfaces of the followers 5 and 6. The surface l2 of the follower I4 is inclined with respect to the vertical and is formed along a plane which makes an angle with the plane of the surface I211 which is likewise inclined with respect to the vertical. Similarly, the lower cam surface I3 is inclined to the vertical and is formed along a plane forming an angle with the plane of the inclined surface l3a. Cam member I I is likewise formed with four sets of inclined surfaces. A pair of springs I8 and 22 urge the cam members I 4 and II outwardly and into engagement with the respective inclined surfaces of the followers 5 and 5. A bolt l9 passes axially through the springs l8 and 22 and is provided with a bolt head 20 and a nut 2|. The bolt head and the nut act as stops to limit the outward movement of the cam members II and M.

In operation, the assembly is such that the lowermembers 5' are supported on the spring planks as can readily be seen by reference to Figure 1. The upper followers 6 directly support the truck bolster 4. Since the load is carried by the bolsters, any thrust occasioned by the load will be directly transmitted to the upper follower members 6. This thrust will serve to compress members 5 and 6, tending to move along toward each other. When this occurs, the inclined surfaces of the followers will force the cams II and I4 toward each other against the action of the springs l8 and 22. There will be motion of the follower members along the inclined surfaces of the cams. This motion is resisted by friction. which friction acts as a snubbing or damping means, preventing harmonic motions. Due to the fact that the followers are formed with a pair of surfaces extending along intersecting planes, lateral motion of the cams with respect to the followers is prevented.

It will be seen that I have accomplished the objects of my invention and have provided a novel railway car truck fitted with a spring assembly comprising an improvement over my prior Patent 2,110,004. The coacting inclined surfaces formed along intersecting planes act to prevent lateral motion of the cams.

Having thus described my invention, I claim:

In a railway truck, a spring assembly comprising in combination, a channel member having a pair of upstanding flanges formed with downwardly and inwardly inclined surfaces, said surfaces being formed along intersecting planes, a second channel member spaced above said first channel member having flanges formed. with upwardly and inwardly inclined surfaces, a pair of cam members positioned between said channel members, having inclined surfaces in contact with the inclined surfaces 'of said channel members, a coil spring horizontally positioned between said cam members, urging them to cam said channel members apart, and a limiting rod axially positioned within the spring for limiting the outward movement of said cam members, recesses in the outside surfaces of the cam members adapted to recessthe end of the limiting rod below the surfaces of the cam members.

EDWARD P. OCONNOR.

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