US3109387A - Side frame-bolster interlocking arrangement for snubbed trucks - Google Patents

Description

N 1963 c. E. TACK SIDE FRAME-BOLSTER INTERLOCKING ARRANGEMENT FOR SNUBBED 'mucxs Flled Nov 6, 1959 2 Sheets-Sheet l 1 w v n INVENTOR.v 5M a @104 Nov. 5, 1963 c. E. TACK SIDE FRAME-BOLSTER INTERLOCKING ARRANGEMENT FOR SNUBBED TRUCKS 2 Sheets-Sheet 2 Filed Nov. 6. 1959 United States Patent F 3 109,387 SIDE FRAME-BOLSTER INTERLOCKING AR- RANGEMENT FGR SNUBBED TRUCKS Carl E. Tack, Elmhurst, IiL, assignor to Amsted Industries Incorporated, Chicago, Ill., a corporation of New r e Je s y Filed Nov. 6, 1959, Ser. No. 851,423

3 (Iiaims. (Cl. 105-197) This invention relates to railway freight car snubbed trucks, and more particularly to an improved side framebolster interlocking arrangement therefor.

The invention comprehends a side frame-bolster interlocking arrangement adapted to prevent or minimize horizontal and rotational movement of the bolster relative to the side frames.

Before the present day snubbed trucks came into existence, all of the freight car trucks were constructed with a minimum of clearance between the inside surfaces of the side frame column walls and the adjacent outer surfaces of the bolster side walls, so that transverse shifting of the bolster on the load supporting springs in a direction longitudinal of the truck and also rotation of the bolster about its longitudinal axis was minimal and not sufficient to create any problems.

In the snubbed trucks of the present day freight cars, however, in order for the snubbing mechanisms to be operable the friction shoes must have room to move transversely of the bolster as they are actuated by their springs. When the friction springs are in normal compressed or expanded condition they urge their related friction shoes into snug engagement with the adjacent side frame column surfaces and normally in so doing serve to maintain clearance between the bolster and side frame columns. However, it has been found that in certain instances where cars have been subjected to unusually severe longitudinal jolts or bumps, as a result of abusive humping practices, bolsters have been displaced to such an extent that the friction springs are no longer effective in maintaining proper clearance between the bolster and side frame column surfaces.

As most cars can incur bumps at speeds up to six miles per hour without having their bolsters displaced, this problem does not occur during normal switching operations but only as a result of negligent or careless handling of the cars during switching or humping operations.

Although in recent years the introduction of automatic classification yards has reduced, to a certain extent, the great volume of conventional switching operations Wherein freight cars are humped, nevertheless it is completely impossible to eliminate humping altogether.

Actual tests have demonstrated that at speeds of approximately mph. or greater there is a tendency of the bolster to rotate about its longitudinal axis relative to the side frame. With the arrested motion of the car body the truck tends to continue forward and an instantaneous tilting action is imparted to the truck bolster, releasing part of the supporting springs, and, if violent enough, enabling the springs to pop out of the side frames.

Another result of severe shock is that with the truck tending to continue forward the rotational movement of the bolster tends to release the forward supporting springs and compress the rear springs, so that the bolster is jammed against forward side frame columns and released from the rear side frame columns. With the bolster tilted and jammed against one pair of side frame columns the friction devices on the side of the bolster adjacent those columns are over-compressed while the friction devices on the opposite sides of the bolster are over-extended. This naturally produces abnormal wear patterns 3,109,387 Patented Nov. 5, 1963 ice If the bolster has been jammed against corresponding side frame columns with enough force, it can shift laterally on the load supporting springs so that the frictional resistance between the upper surfaces of the load springs and the lower surface of the bolster is too greater to permit the bolster to return, or be urged by the friction springs, to proper position relative to the side frame columns.

It is possible that a relatively slight displacement of the bolster and a minor dislodgement of the load springs could occur without being noticed as a car continues in service. Under these conditions snubbing action would still take place as the load taken from the snubbing devices on one side of the bolster would be added to the other; however, uneven or erratic wear patterns would occur and the service life of the parts would be shortened.

Thus, inasmuch as a snubbed truck requires a definite predetermined distance between the side frame columns and the friction shoes in the bolster opening, in order to prevent any erratic or uneven wear patterns on the snubbing surfaces and to insure optimum service life of the parts, it is desirable to maintain this distance and provide some other means for restricting horizontal or rotative movement of the bolster Within the opening.

Accordingly, it is a primary object of this invention to provide in a snubbed railway car truck a means of restricting undesirable horizontal or rotative movement of the bolster relative to the side frames without decreasing the space between the friction surfaces of the side frame column walls.

A more specific object of the invention is the provision of a side frame-bolster arrangement having special stop means on the side frame, engageable with the side walls illustrated in FIGURE 1, with portions of the structure shown in vertical section;

FIGURE 3 is an enlarged top plan view of a portion of the structure illustrated in FIGURE 1, with portions of the structure shown in horizontal section, and

FIGURES 4 and 5 are schematic diagrams illustrating the relationship of related bolster and side frame column surfaces in a conventional snubbed truck and in a snubbed truck embodying features of the invention, respectively.

It will be understood that certain elements have been intentionally omitted from certain views where they are illustrated to better advantage in other views.

Referring now to the drawings for a better understanding of the invention it will be seen that the invention is applied to a railway car truck comprising a pair of side frames, indicated generally at 10, which are interconnected by a transversely extending bolster, indicated generally at 12, and which are supported at their ends by a pair of wheel and axle assemblies, indicated generally at 14. Only portions of one side frame and one Wheel and axle assembly are shown in the drawings as the side frames are identical, as are the wheel and axle assemblies, and each side frame is symmetrical with respect to its vertical transverse center plane.

As best seen in FIGURE 1, each side frame comprises 3 a pair of longitudinally extending tension and compression elements 16 and 18, respectively, which are merged at their ends to form housing means 20 for journally receiving the wheel and axle assemblies 14 in a conventional manner. Intermediate of their ends the tension and compression elements are spaced from each other and interconnected by a pair of integral vertically extending columns Z2 spaced from each other lengthwise of the side frame to define a holster opening 24 therebetween.

As best seen in FIGURE 1, bolster 12 includes a pair of box-like ends 26 (only one of which is shown) each of which is supported on a plurality of coil compression load springs 28 which in turn are positioned on a spring seat 60 presented by side frame tension element 16 in bolster opening 24.

Each bolster end, as best seen in FIGURE II, has a pair of pockets 3-2 disposed on opposite sides thereof adjacent related side frame columns 22. Within each pocket there is provided a friction shoe 34 and spring 36 operable to urge the shoe into frictional engagement with a Wedge wall 38 presented in the bolster pocket and with a vertical friction surface 4% presented by a wear plate 4I2 rigidly secured to a vertical wall 44 of the adjacent side frame column 22.

The structure of the friction shoe and spring arrangement is notshown in detail as it does not form an essential part of this invention and may be of any desired type such as that described and illustrated in detail in Patent 2,378,414, particularly in connection with FIGURES It is well known by those familiar with the art of railway car trucks that snubbing devices of the type previously described are commonly used to damp vertical oscillations of the bolster supporting springs 28. In their operation the friction springs 36 react between the bolster and friction shoes to urge the shoes up against the wedge walls 38 and the wedging action between the wedge walls and the shoes urges the shoes outwardly and into frictional engagement with friction surfaces presented by adjacent side frame columns. The entire snubbing arrangement can be reversed with the friction shoes and springs being carried in pockets of the side frame oolumns so that the friction springs react between the side frame columns and the shoes to urge the shoes into engagement with wedge walls in the columns and with vertical side walls of the bolster. In either arrangement the result is the same. In both arrangements (only the first described arrangementbeing herein illustrated) the bolster opening must be wide enough to afford some degree of lateral or sidewisemovement in the bolster opening in a direction lengthwise of the side frame. It is also known that the bolster must be afforded freedom for some limited degree of lengthwise movement in a direction sidewise of the side frame.

Longitudinal movement of the bolster can be limited by providing on each side of the bolster end a pair of inboard and outboard lugs tor gibs 4.6 and 48, respectively,

which project in a direction normal to the longitudinal axis of the, bolster and which are disposed adjacent the inboard and outboard sides, respectively, of inboard and outboard vertical flanges 50 and 52, respectively, of the side frame columns.

Although the friction shoes are only aiforded a limited degree of horizontal movement, they can not be used as stop means to limit sidewise movement of the bolster between the columns of the side frame, because if they were the only stop means they would merely ride back and forth on the wedge walls and permit the bolster to move freely in both vertical and horizontal directions.

In the prior art the means for limiting lateral or sidewise movement of the bolster between the side frame columns has been the engagement between the corners 56 or the sideframe columns, which are located outboardly adjacent opposite sides of the wear plates 4-2, and the adjaopening of the side frame.

cent shoulders 54 of the bolster, which are located inboardly adjacent opposite sides of the bolster pockets 32.

In the prior art devices there has been a great variation in the amount of over all distance provided between the side frame column flange surfaces 56 and the bolster wall vertical surfaces 54, but in all cases this distance was so great as to permit an undesirable amount of lateral shifting of the bolster in the bolster opening of the side frame. As a result of this excessive play, when cars are subjected to extreme longitudinal shocks as in coupling operations, the bolster tends to do two things: It shifts sideways up against the forwardmost columns causing the load springs 28 to tilt, or angle relative to the vertical. When this occurs the springs sometimes remain in a tilted or cooked position and maintain the bolster jammed up against the front columns so that it never centers itself. This results in a malfunction of the snubbing means as the car continues in service. Also, at times of longitudinal shock to the car the bolster, if permitted an excessive amount of play, tends to rotate about its longitudinal axis. Rotation of the bolster member, if great enough, can cause the load springs 2-8 to pop right out of the car, or at least tilt enough to jam the bolster against. the front columns. Also, if great enough, it can displace the pivotal connection between the bolster and car body.

Although the harmful effects of bolster rotation or shifting were known in the art, no way was known to reduce the clearance between the bolster and side frame members in a manner that would still perrnit easy assembly of the truck and proper functioning of the snubbing means.

Attempts were made to build up the surfaces 54 of the bolster so as to decrease the distance between them and the adjacent surfaces 56 of the side frame, but because the areas of contact between them are so small and the pressure is so great these corner and shoulder surfaces wore down, after extremely brief periods of service, to the point where excess play between the members again occurred.

I have discovered that lateral movement of the bolster can be properly restricted to the desired degree by providing stop lugs 58 on the inboard sides of inboard flanges of the side member columns. Stop lugs 58 extend in- ,boardly and present surfaces 60 which face outwardly facing surfaces 62 presented by adjacent inboard bolster gibs 46. With this arrangement, if surfaces 60 are disposed a proper distance from surfaces 62, the holster movement can be limited to that degree which is absolutely necessary.

Although prior art devices, such as that disclosed in the previously mentioned Patent 2,378,414 have been pro columns, and thereby eliminate the need for providing bolster gibs on both the inboard and outboard sides of the side frame columns. In these prior art devices the column lugs were never intended to function as a stop means for limiting sidewise or transverse movement of the bolster lengthwise of the side frame in the holster This sidewise bolster movement was, in conventional snubbed trucks, limited by the engagement between the surfaces 54 of the bolster side walls and the surfaces 56 presented by the side frame column flanges 5 0 and 52.

As the clearance between the bolster gibs and side frame column lugs was greater than the clearance between the related vertical surfaces of the bolster and side frame columns, the latter clearance was controlling and determined the maximum amount of movement of the bolster in the bolster opening of the side frame.

FIGURES 4 and 5 are schematic diagrams illustrating the relationship of engaging bolster and side frame column surfaces in conventional snubbed truck arrangements and in a snubbed truck embodying my invention, respectively.

The dimensions for both figures are based on the nominal dimensions of :a conventional 50 ton snubbed truck and are as follows:

FIGURE 4 (Conventional Snubbed Truck) BDistance between bolster gib surfaces (62 62) 16 /8 C-Distance between side frame column stop surfaces 6fl6i3) 16 D'Effective transverse diagonal dimension of bolster 17. 12 2E-Overall clearance between bolster and side frame surfaces E'-Clearance at one side between bolster and side frame surfaces In the arrangement illustrated in FIGURE 4 the ratio of the overall clearance between the bolster and side frame surfaces (2E) to the effective transverse diagonal bolster dimension (D) is approximately 3 to 100 or, in other words, the clearance is 3% of the effective bolster dimension. In this arrangement the bolster is free to 1'0- tate about its longitudinal axis to the extent that it can angle in excess of 7 relative to the horizontal.

In the arrangement of FIGURE 5, however, the ratio of the overall clearance (213') between the bolster and side frame surfaces to the effective transverse diagonal bolster dimension (D) is approximately 1 to 100 or in other words the clearance is 1% of the effective bolster dimension. In this arrangement the spacing between the abutment surfaces so and 62 is less than one-quarter inch and the maximum angle of rotation for the bolster is less than 2.

The difference between the amount of rotation permitted in conventional snubbed trucks and that permitted in snubbed trucks embodying my novel bolster stop arrangement has been proven by actual tests to be highly significant.

When cars equipped with conventional snubbed trucks were subjected to bumping shocks at speeds in excess of 10 m.p.h., bolster displacement was a common occurrence; whereas cars equipped with trucks having my bolster stop application were subjected to bumping shocks at speeds up to 18 mph. without appreciable bolster displacement.

I claim:

1. In a railway car truck the combination of: a side frame having a pair of spaced rigid vertical columns defining a bolster receiving opening therebetween; vertically extending frictional guide surfaces formed on respective columns in planes substantially transverse to said side frame; a bolster member extending transversely of said side frame and having an end extending through said opening; snubbing means carried by said bolster and resiliently urged outwardly against said frictional guide surfaces in a manner causing clearances between the sides of said bolster and said columns; spring means in said opening supporting said bolster end on said side frame; first abutment surfaces formed on said vertical columns inboard of said side frame in planes substantially longitudinal of said frame; second abutment surfaces formed on said vertical columns outboard of said side frame in planes substantially longitudinal of said frame; first vertically extending gibs formed on said bolster end outboard of said side frame; third abutment surfaces formed on said firs-t gibs in a manner causing said second and third abutment surfaces to be in juxtaposition to each other; second vertically extending gibs formed on said bolster end inboard of said side frame; fourth abutment surfaces formed on said second gibs in a manner causing said first and fourth abutment surfaces to be in juxtaposition to each other; third vertically extending gibs formed on the inboard side of said side frame and oppositely disposed about said bolster; fifth vertically extending abutment surfaces formed on said third gibs in planes substantially transverse to said side frame; and vertically extending sixth abutment surfaces formed on said second gibs substantially transverse to said side frame and in juxtaposition to said fifth abutment surfaces; said respective fifth abutment surfaces and said respective sixth abutment surfaces being so spaced from each other so as to have a total clearance therebetween no greater than one-quarter inch and substantially less than the total clearance existing between said sides of said bolster and said friction guide surfaces on said columns, whereby rotation of the bolster about its longitudinal axis is limited to less than 2.

2. In a railway car truck the combination of: a side frame having a pair of spaced rigid vertical columns defining a bolster receiving opening therebetween; vertically extending friction surfaces formed on respective columns in planes substantially transverse tosaid side frame; a bolster member extending transversely of said side frame and having an end extending through said opening; snubbing means carried by said bolster and resiliently urged outwardly against at least one of said friction surfaces in a manner causing a clearance between said bolster and said columns; resilient means in said opening supporting said bolster end on said side frame; first abutment surfaces formed on said vertical columns inboard of said side frame; second abutment surfaces formed on said vertical columns outboard of said side frame; first vertically extending gibs formed on said bolster end outboard of said side frame; third abutment surf-aces formed on said first gibs in a manner causing said second and third abutment surfaces to be in juxtaposition to each other; second vertically extending gibs formed on said bolster end inboard of said side frame; fourth abutment surfaces formed on said second gibs in a manner causing said first and fourth abutment surfaces to be in juxtaposition to each other; third vertically extending gibs formed on the inboard side of said side frame and oppositely disposed about said bolster; fifth vertically extending abutment surfaces formed on said third gibs in planes substantially transverse to said side frame; and vertically extending sixth abutment surfaces formed on said second gibs substantially transverse to said side frame and in juxtaposition to said fifth abutment surfaces; said respective fifth abutment surfaces andsaid respective sixth abutment surfaces being so spaced from. each other so as to have the total clearance therebetween no greater than one-quarter inch and substantially less than said clearance existing between said bolster and said friction surfaces on said columns, whereby rotation of the bolster about its longitudinal axis is limited to less than 2.

3. A railway car truck, comprising a side frame having axle journal means at its ends, a bolster resiliently mounted on said side frame, first means for positively limiting relative lateral movement of said bolster transversely of said side frame, second resilient means effective for inhibiting both the vertical movement of said bolster relative to said side frame and the lateral movement of said bolster longitudinally of said side frame, and additional means for positively limiting rotation of the bolster about its longitudinal axis to less than 2, said additional means comprising rigid abutment means on the bolster and frame for positively limiting the total lateral movement of said bolster longitudinally of said side frame to a distance no greater than one-quarter inch and less than that distance permitted by said second resilient means.

UNITED STATES PATENTS Clasen -4 Jan. 6, 1931 Hamilton Apr. 14, 1931 Hobson Feb. 20, 1940 Darrows May 14, 1940 Cottrell Apr. 5, 1949 Cottrell Jan. 24, 1950 Le-ese n Feb. 14, 1950 Settles Nov. 15, 1955

Claims (1)

1. IN A RAILWAY CAR TRUCK THE COMBINATION OF: A SIDE FRAME HAVING A PAIR OF SPACED RIGID VERTICAL COLUMNS DEFINING A BOLSTER RECEIVING OPENING THEREBETWEEN; VERTICALLY EXTENDING FRICTIONAL GUIDE SURFACES FORMED ON RESPECTIVE COLUMNS IN PLANES SUBSTANTIALLY TRANSVERSE TO SAID SIDE FRAME; A BOLSTER MEMBER EXTENDING TRANSVERSELY OF SAID SIDE FRAME AND HAVING AN END EXTENDING THROUGH SAID OPENING; SNUBBING MEANS CARRIED BY SAID BOLSTER AND RESILIENTLY URGED OUTWARDLY AGAINST SAID FRICTIONAL GUIDE SURFACES IN A MANNER CAUSING CLEARANCES BETWEEN THE SIDES OF SAID BOLSTER AND SAID COLUMNS; SPRING MEANS IN SAID OPENING SUPPORTING SAID BOLSTER END ON SAID SIDE FRAME; FIRST ABUTMENT SURFACES FORMED ON SAID VERTICAL COLUMNS INBOARD OF SAID SIDE FRAME IT PLANES SUBSTANTIALLY LONGITUDINAL OF SAID FRAME; SECOND ABUTMENT SURFACES FORMED ON SAID VERTICAL COLUMNS OUTBOARD OF SAID SIDE FRAME IN PLANES SUBSTANTIALLY LONGITUDINAL OF SAID FRAME; FIRST VERTICALLY EXTENDING GIBS FORMED ON SAID BOLSTER END OUTBOARD OF SAID SIDE FRAME; THIRD ABUTMENT SURFACES FORMED ON SAID FIRST GIBS IN A MANNER CAUSING SAID SECOND AND THIRD ABUTMENT SURFACES TO BE IN JUXTAPOSITION TO EACH OTHER; SECOND VERTICALLY EXTENDING GIBS FORMED ON SAID

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