US3796167A

US3796167A - Elastomeric railway car side bearing

Info

Publication number: US3796167A
Application number: US00328858A
Authority: US
Inventors: Moss J Van
Original assignee: MOSS J VAN
Current assignee: MOSS J VAN
Priority date: 1973-02-01
Filing date: 1973-02-01
Publication date: 1974-03-12
Anticipated expiration: 1991-03-12

Abstract

A side bearing or snubber having an upright body member constructed of a hard elastomeric material such as polyurethane and having an integral flanged base for attachment to the truck bolster of a railroad car providing for the resilient support of the car frame when installed for the absorption of dynamic forces of car motion by the compressive travel thereof, the snubber having a central bore extending through said body and base containing a shortened steel column therein for limiting said compressive travel, the bore being relieved adjacent to said base whereby under substantially full compression with the tilting of the car against the snubber, the snubber is compressed into a shallow oval-like bulbous shape, whereby the upper portion of the body grips the upper end of the column and urges it in frictional restraint forcing it to return to static position and in support of the car frame from its dynamic travel from car swaying and tilting.

Description

[ 1 Mar. 112, 1974 1 ELASTOMERIC RAILWAY CAR SIDE BEARING [76] Inventor: John H. Van Moss, Jr., 3 Mavor Ln., Highland Park, 111. 60035 [22] Filed: Feb. 1, 1973 [21 Appl. N0.: 328,858

Related US. Application Data [63] Continuation-impart of Ser. No. 176,119, Aug. 30,

1971, abandoned.

[52] US. Cl 105/199 CB, 267/3, 267/63 R, 308/138 [51] Int. Cl. B61f 5/14, F16c 17/04, F160 17/08 [58] Field of Search 105/199 C, 199 CB; 267/3, 267/63 R; 308/138 FORElGN PATENTS OR APPLICATIONS 1,354,286 l/l964 France 267/63 R Primary Examiner-Robert G. Sheridan Assistant Examiner-Howard Beltran Attorney, Agent, or FirmW. A. Snow; C. W.

Rummler [57] ABSTRACT A side bearing or snubber having an upright body member constructed of a hard elastomeric material such as polyurethane and having an integral flanged base for attachment to the truck bolster of a railroad car providing for the resilient support of the car frame when installed for the absorption of dynamic forces of car motion by the compressive travel thereof, the snubber having a central bore extending through said body and base containing a shortened steel column therein for limiting said compressive travel, the bore being relieved adjacent to said base whereby under substantially full compression with the tilting of the -car against the snubber, the snubber is compressed into a shallow oval-like bulbous shape, whereby the upper portion of the body grips the upper end of the column and urges it in frictional restraint forcing it to return to static position and in support of the car frame from its dynamic travel from car swaying and tilting.

8 Claims, 9 Drawing Figures 1 ELASTOMERIC RAILWAY CAR SIDE BEARING This application is a cont-inuation-in-part of my copending application Ser. No. 176,119 filed Aug. 30, I971, now abandoned.

BACKGROUND OF' THE INVENTION This invention relates to the art of dynamic stabilization of all types of freight cars in transit on standard roadbeds by the absorption of energy of shock and the dampening and limitation of dynamic motion of the body of the car in the vertical, lateral and horizontal or swaying directions.

Side snubbers embodying rollers movably mounted in a frame supported on a truck bolster which are contacted by the car body are old. Also, some preloaded side snubbers are known to utilize spring-loaded cam systems. Insofar as solving the problem of dynamic rocking motion resulting .in derailments of railroad cars, snubber members have been used in conjunction with the springs between the truck bolster and the side frame of the car. None of the foregoing have been found to provide an inexpensive structure which will reduce the dynamic condition which causes the car bodies to sway from side to side under self-excited vibration and create a problem which is known in the railroad industry as resonant rock and roll. More specifically, this condition has been encountered with high covered hopper cars and some high-side gondolas capable of carrying between a hundred and a hundred and twenty-five tons of material. These cars are normally approximately the same length as the standard rail and with the staggered joints between the rails and a forced resonant vibration condition, can be set up at some of the lower speeds of travel.

As now understood, this swinging of the car body from one side to the other contacts the side snubber which is located between the car body and the truck bolster. The forces are transmitted through the bolster and into the spring group and the side frame of the truck. From there, the force goes to the car journals and onto the axles on the outboard side of the wheels of the truckQThis causes the wheels and the rail on that particular side to-form a fulcrum point, lifting the wheel from the track on the opposite side. Most of the time the wheels on the far side return and make contact with the rail. In newer cars with larger loads and greater excitation forces, the wheels, on returning to the level, miss the rail, causing derailments. A second condition which is causing derailments occurs when the dynamic rocking of the car becomes so violent that the forces transmitted down through the truck bolsters and frame into the wheels are great enough to actually turn the rail over on the tie.

At the present time, there are no firm specifications by the Association of American Railroads regarding resilient-type side snubbers. However, it has been decided informally that such side snubbers should have an initial preload of 5,000 pounds on each side of the car, at a resilient deflection of approximately one-quarter inch. As the car body rocks in dynamic motion, the resistance of the side snubber should increase 50,000 pounds with an additional deflection of approximately 1 inch. The side snubber disclosed herein substantially meets the foregoing informal specifications and contributes to a reduction of the aforesaid conditions which have resulted in derailments.

There is thus a need in the railroad industry for a low cost, preloadable side snubber which retains its original resilience throughout its life and which stabilizes the dynamic motion ofa freight car in transit at all reasonable operating speeds and rated car loadings. Reduction of rocking of the car, lift of the wheels off the rail and lateral hunting of the trucks by means of positive action shock control of the freight car motion through the use of such side snubbers will reduce excessive wear of rail, wheel and equipment during life, and lead to trouble-free maintenance during operation and improve customer service relations from reduced damage to lading for sales.

Side snubbers containing short rods therein, which rods were designed to return to their upper static position, have a tendency to fail under extreme load conditions,'because the rods having a less hardness than the truck bolster will tend to form a permanent enlargement at the bottom thereof, due to constant impact, so that the snubber becomes ineffective. Under such conditions, the rods and ends remain in contact with the bolster rather than contacting the car frame.

SUMMARY OF THE INVENTION The inventive concept involved in this improved side snubber for railroad cars comprises a hard elastomeric side bearing having an upright body member and an axial bore with a bore relief adjacent the base thereof, the bore containing a shortened steel column for limiting the compressive travel of the snubber under dynamic car loading. The upper portion of the body, in combination with the bore relief, grips said column adjacent its upper end under dynamic loading and urges it in' frictional restraint to return to its static position against the car frame with its top end flush with the body top upon the relief of load while the bore relief also provides clearance ifa permanent enlargement at the end of the steel column coming from continued impact on the truck bolster occurs, thereby maintaining resilience of the side bearing during operating life.

It is thus another object of this invention to provide for energy-absorbing elastic truck side snubbers satisfying the above need.

Another object of this invention is to provide elastic truck side snubbers which provide toughness and resistance to abrasion and having the ability to absorb energy and to dampen the vertical, lateral, longitudinal and swaying shock forces having their origin in high speed and heavy load travel, thereby preventing wear and tear on the rolling stock-and the rails and roadbed of the railroad.

Another object of this invention is to provide means for retaining a short steel column in the upper end of the side snubber when the bearing is in static position.

Still another object of this invention is to provide for the continued safety of the shock control operation of the freight car by limiting maximum car motion with positive action steel stops which are maintained in physical contact with the plate on the ear frame by the urging action of a side snubber. Such stops will continue to function as stops without reducing the resilience of the side snubber regardless of the possibility of permanent deformation at the lower end of the stop from successive impacts imposed thereon as the limit of maximum travel is reached.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmented elevation view of the railroad car frame and truck bolster with the improved side snubber mounted therebetween;

FIG. 2 is a perspective elevation view of the improved side snubber of upright body member and shallow frusto-conical-like shaped top;

FIG. 3 is a vertical sectional view through the center line of the body and the mounting holes of the flanged base of the side snubber showing a bore relief providing frictional restraint of the steel column therein;

FIG. 4 is a perspective view of the center steel column with deformed end;

FIG. 5 is a vertical sectional view of a modification showing another type of stepped bore relief;

FIG. 6 is a vertical sectional view of a modification showing a flanged restraint of the steel column in the body of the snubber;

FIG. 7 is a perspective view of another body form of side snubber;

FIG. 8 is a vertical cross-sectional view ofa modified form of snubber body and FIG. 9 is a cross-sectional view of another modified form of structure similar to FIG. 6.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIG. 1, the side bearing or snubber 10 that is the subject invention is located on a truck bolster l2 and is installed with conventional bolts 16 running through flanged base 18 in the same position and manner as the current solid side snubbers. The top end 20 of side snubber 10, shown in FIG. 2, bears on wear plate 22 which is integrally formed on the bottom ofthe car frame 14, shown in FIG. I. The integral flanged base 18 of the snubber 10 in FIG. 2 has mounting holes 24 in opposite ends of the base 26 for receiving bolts 16 in the mounting of the side snubber base 18 to bolster 12.

A body member 30 of the side snubber 10 is an integral part of the base 18, as shown in FIG. 2. As shown in FIG. 3, the body member 30 is centrally located on base 18 extending up therefrom as side surface 19 having the shape of an upright frustrum of a circular cone and terminating in top 20 in the form of a shallow frusto-conical-like shape 34 from a flat center section 36 to the upper surface 19 of the body member 30, giving maximum stability and preventing rollover of the side snubber under load, and maintaining bearing contact of the upper end 43 of steel center column 42 against plate 22 on car frame 14 when the snubber 10 is compressed into a shallow oval like bulbous shape, as shown in dotted line in FIG. 3, whereby the upper portion 31 of body member 30 grips the upper surface 43 of column 42 as indicated by the force vectors indicated by the arrows in FIG/3 shown in dash lines. This shaping of the body member 30 of the side snubber l0 permits a limited amount of elastomeric material to compress under maximum deflection forces. The top 20 may be impregnated with particles of either teflon or molydisulfide to make the surface slippery to facilitate relative movement between the top 20 and plate 22 depending from car frame 14.

the side snubber is provided with bore 38 extending axially from the top 20 through the base 18, as shown in FIG. 3. The bore 38 is preferably 1% inches in diameter before shrinking during cooling after being removed from the mold. The overall free height H of the snubber is preferably 5% inches. The installed height H', as compressed by the static weight of the railroad car, is approximately 5 /2 inches. The minimum working height H" of the snubber under maximum loading is approximately 4 to 4% inches. Bore 38 has a straight taper terminating in downwardly and arcuately formed relief 40, the relief extending up through base 18 into body member 30 a distance terminating preferably approximately 2 inches from the top 20 of a steel center of the body member 30. The arcuate portion forming the relief 41 is preferably on a 4- inch radius. Counterbore 46 of the modified side snubber l0 shown in FIG. 5 is preferably of 1% inches diameter and of the same depth into the body member 30' from the base 18 and serves equally satisfactorily to relieve the bore 38.

In a further modification, side snubber l0 as shown in FIG. 6, is of the same outline as that shown in FIG. 3 except the steel column 42 has an integrally formed flanged upper end 47 for restraining the column 42" in body 30" and urging it toward the top 20 of side snubber M).

Steel center column 42, as shown in FIG. 4, which preferably has a diameter of approximately 1% inches plus, is slightly greater than the diameter of the bore 38, and has a length of approximately 4% inches, which is less than the preloaded height H of the snubber 10. The column 42 is frictionally restrained in bore 38 with upper end 43 flush with the top surface of body member 30 for contacting plate 22 on car frame 14, as shown in FIG. 1. The lower end 45 of the column 42 is preferably spaced about 1% inches from the truck bolster in static position. Thecolumn 42 thereby limits maximum compression travel of the side snubber under maximum load with lower end 45 coming into contact with bolster 12. The body 10 will then be compressed into the bulbous shape shown in dashed outline in FIG. 3, thus causing the upper end 43 of body 10 to grip and constantly keep in contact against the lower surface of plate 22 in the process. Thus the column 42 is always assured of being returned to its starting static position. The effect of the introduction of the steel column 42 in the center of the body member 30 also is to increase the non-linear load response characteristics of the

side snubber

10, 10' or 10" under high loadings.

The enlargement 44 on lower end 45 of steel center column 42 shown in FIG. 4 comes as the possible result of the peening over of the end of column 42 under repetitive impact up against the limit of travel of the snubber from dynamic loading during use, because the column 42 is constructed to be not as hard as the bolster 12 or plate 22. The relief 41 will still allow the column 42 to return to static position since the relief forms a clearance for the enlargement 44. Thus, as installed with the preferable dimensions and under rated static preload, the working travel between lower end 45 of column 42 and bolster 12 before bottoming-out under maximum dynamic loading will normally approximate to 1 inch unde loading conditions of 50,000 pounds attainable when the railroad car is moving on a curved banked track.

In the modification of FIG. 6, the flanged member 47 of the column 42" is seated in a recess 48 formed in the upper surface 20" to insure return of the column 42" to its static position as aforesaid.

The elastomeric material of the side snubber of this invention is most preferably a polyurethane having a hardness of at least 50 to 90 Shore D Scale.

FIGS. 7 and 8 disclose another form of side snubber 50 with an integrally formed, outwardly extending flanged base 52 adjacent the lower end of the body 54. The flanged base is provided with a pair of opposed apertures 56 each containing a bushing 58.

The body 54 is substantially cylindrical in shape and substantially from 4 V2 to 5 /2 inches in diameter with the side wall provided with a taper of about 5 to allow the same to be molded. The molding material is polyurethane having a hardness of 50 to 90 Shore D Scale, similar to the other embodiments disclosed herein. The top wall 60 is a flat surface.

The axial bore 38 and the

relief

40 and 41 shown therein are the same as in the other embodiments described hereinabove, as is the column 42.

The side bearing 50 of FIG. 9 is identical to that shown in FIG. 8 except the top 60 is formed with a recess 62 to seat the head 64 of the column, similar to the device shown in FIG. 6.

Major railroads have tested the device of this invention at high speeds on 89 inch flat cars with containers, 70-ton bulkhead flat cars, standard 50 inch box cars, covered hoppers, Vert-A-Pacs, Stac-Pacs, steel coil cars, auto parts cars and 60 inch appliance cars.

The consensus of these tests is that the device of this invention will raise the threshold of high-speed lateral truck hunting l0 m.p.h., and reduce it substantially beyond that.

For instance, lateral twist on 89 inch flat cars with containers was cut by percent to 60 percent, depending on speed. On 70-ton bulkhead flat cars and standard 50 inch box cars, the threshold of sustained lateral truck hunting was raised from 45 m.p.h. to 70 m.p.h.

All this-means that the device of this invention will greatly decrease center plate damage, wheel flange wear and lading damage caused by high-speed vibra tlon.

The device of this invention has also performed an excellent job on low-speed wheel lift. Tests have shown that the load transferred from bolster to bolster through the device of this invention is about 55,000 lbs., compared to 150,000+ with solid side bearings.

As a result, it eliminates cracked bolsters, center plate separation and broken springs.

ln a recent high-speed Vert-A-Pac test, the device of this invention produced the lowest vertical force among a number of devices. Yet it also reduced vertical force at low speeds.

A leading railroad is now installing these side bearings on its fleet of Vert-A-Pac cars.

lt was also found that the device substantially reduces the noise levels in cabooses and improves the ride.

Thus the device of this invention will substantially increase mileage between car shoppings, and it will also keep standard cars from wearing out.

ALthough several specific embodiments of this invention have been herein shown and described, it will be understood that details of construction shown may be altered or omitted without departing from the spirit of the invention as defined by the appended claims.

l claim:

1. A device of the class described comprised of a hard elastomeric material having a flanged base, an upright cylindrical-shaped body integrally formed on said base having a flat top, an axial bore extending from said top to and through said base, a bore relief means coaxial with said bore extending from said base into said body, a steel column held in said bore and having a length less than the preloaded height of said snubber, whereby the column is restrained by the body of said snubber and urged to its static position.

2. The device of claim 1 wherein the top surface of the steel column is provided with a flange and the upper end of said body contains a recess for seating said flange.

3. A side snubber for a railroad car comprised of hard elastomeric material having a flanged base, a tapered upright body member integrally mounted on the base, a top of said body having a flat center section, an axial bore extending from said top through to said base of said body, a bore relief means coaxial with said bore extending from said base into said body, a steel column held in said bore having a diameter slightly less than that of said bore and a length somewhat less than the preloaded height of the snubber whereby the steel column is restrained by the body of the snubber and urged to its static position.

4. A side snubber as set forth in claim 3 wherein said bore relief means comprises clearance providing for the operational enlargement of the end of the steel column during the life of the snubber to keep the resilience of the snubber maintained.

5. A side snubber as set forth in claim 4 wherein the elastomer is a polyurethane material.

6. A side snubber as set forth in claim 3 wherein the bore relief means is formed by an arcuate taper extending from the lower surface of the body upwardly to a straight conical taper terminating in said axial bore whereby when said snubber is compressed under full load condition, the body member forms a shallow ovallike bulbous shape and the upper portion of the body grips the upper end of the column and urges it toward the top of the snubber when the load is released.

7. A side snubber as set forth in claim 6 wherein the hardness of said elastomeric material is at least 50 to 90 Shore D Scale.

8. The device of claim 3 wherein the top surface of the steel column is provided with a flange and the upper end of said body contains a recess for seating

Claims

6. A side snubber as set forth in claim 3 wherein the bore relief means is formed by an arcuate taper extending from the lower surface of the body upwardly to a straight conical taper terminating in said axial bore whereby when said snubber is compressed under full load condition, the body member forms a shallow oval-like bulbous shape and the upper portion of the body grips the upper end of the column and urges it toward the top of the snubber when the load is released.

8. The device of claim 3 wherein the top surface of the steel column is provided with a flange and the upper end of said body contains a recess for seating said flange.