US3461815A - Snubbed railway truck bolster - Google Patents

Description

Aug. 19, 1969 A, E. cas-oms r-:rAL

SNUBBED RAILWAY TRUCK BOLSTER FiledvAug. 1, 196e 5 Sheets-Sheet 1 Aug. 19, .1969 A' E GEDRIS ET AL SNUBBED RAILWAY TRUCK BOLSTER 3 Sheets-Sheet a Filed Aug. l, 1966 4 v M 7S@ Z m H m /J Z I5 M d x FIN -N l Aug.. 19, 1969 A. E. GEDRls ETAL 3,461,815

` SNUBBED RAILWAY TRUCK oLsTER l Filed Aug. -1, 1966 3 sheets-Sheet s United States Patent O U.S. Cl. 10S- 197 9 Claims ABSTRACT F THE DISCLOSURE A snubbed railway car truck of the type wherein pockets for Ifriction wedges are formed primarily by downward-opening recesses in the sides of the end portions of the bolster received in the side frames but having an improved construction enabling full-size load springs standing on the spring seats of the side frames to engage the friction wedges of the truck-snubbing system.

This invention arises out of the need to provide this type of car truck, generally known to the railway and related industries is the Barber truck, in a form adapting it for carrying greater loads while providing adequate snubbing control. Railway car construction, particularly in respect to the trucks thereof, is subject to various dimensional limits dictated lby standardization arising out of the need for railway cars to be able to travel over any commercial railway coupled with any other vehicle adapted for interchange service. Hence, difficult design problems arise in providing an adequate snubbing system along with adequate bolster and side frame strength in car trucks adapted to carry heavier loads than heretofore carried by the Barber truck. For example, a car designer is confronted, as in the present case, with the situation that signicant strengthening of the vehicle in one aspect can be obtained apparently only by weakening the vehicle in some other aspect in order to maintain, e.g., a standard distance between center lines or other required predetermined features of a vehicle.

An especially difcult zone of a Barber car truck in which to achieve strengthening of the bolster or side frame without weakening the other includes structure of each side frame surrounding the bolster opening and those portions of the bolster received in the side frames. For example, any attempt to increase spring capacity entails greater spring seat area. However, if that portion of the bolster within the bolster opening is made wider and stronger, the bolster opening must be made larger with consequent weakening of the side frame and infringement on the region needed for the brake beam brackets and brake mechanism. Moreover, there is an external standard transverse contour of the truck structure established by the Association of American Railways to enable railway undercar parts to clear trackside installations. Present truck designs are already extended to the limits mposed by this standard transverse contour in meeting present demands for greater capacity.

It is a principal object of this invention to provide design criteria for a Barber truck which increase the load capacity of this type of truck from conventional levels, and to provide a truck in accordance With such criteria.

Other objects ancillary to the above objects are (1) to increase the spring capacity and load capacity in general of the truck while avoiding (a) increases in the effective width of the bolster opening as measured lengthwise of the side frame and (b) increases in dimension 0f the spring seat as measured transversely of the side fra-me length; (2) to increase the frictional snubbing capacity of the Barber type car truck; and (3) to increase the width of the bolster relative to the width of the bolster opening in order to achieve high strength values in both the bolster and the side frame.

The above and such other objects as are apparent hereinbelow are achieved in a snubbed car truck of the type having friction wedges housed primarily within bolster recesses in vertically rectilinear guide relation with respective side frame columns. The invention resides essentially in the construction of the bolster, the side frame, and the wedges which enables the undersurface of each wedge to be sufficiently extensive to function as a seat for a full size load spring. To obtain the larger spring seat needed on each of the bottom surfaces of the wedges, the lower portion of the wedge is extended as a flange toward a vertical longitudinal center plane of the bolster, and the bolster spring seat surface is correspondingly indented to provide a shallow extension of each of its wedge recesses. For high strength side-frame construction, the friction surfaces of the columns are recessed inwardly of the column from the periphery of the bolster opening, and the columns comprise anges which extend rectilinearly from the tension member to the compression member of the side fra-me. Thus the columns are of high strength channel-like conformation along their full height and are spaced at opposite sides of the bolster opening merely to an extent which will admit the bolster portion normally received therebetween at any height therealong.

In the drawing in respect to which this invention is described:

In illustration of prior art construction, FIGS. 1, 2, and 3 are (l) a fragmentary view sectioned along line I-I of FIG. 2 in plan, (2) a fragmentary view in elevation and partial longitudinal vertical section of a bolster and side frame, and (3) a perspective view of a friction wedge shown in FIGS. 1 and 2, respectively, of a Barber type truck in common use.

FIG. 4 is a plan view of a railway car truck according to the invention;

FIG. 5 is a perspective view of a friction wedge included in the embodiment of the invention illustrated by FIGS. 7 and 8;

FIG. 6 is a perspective view of a friction wedge included in another embodiment illustrated by FIGS, 9 and l0;

FIG. 7 is a fragmentary plan view illustrating portions of a bolster and a side frame at different levels of cross section as taken along line VII-VII of FIG. 8;

FIG. 8 is a fragmentary elevation partly in section taken along line VIII-VIH of FIG. 7;

FIG. 9 is a fragmentary plan view illustrating portions of a bolster and side frame at diierent levels of crosssection as taken along line IX--IX of FIG. 10; and

FIG. 10 is a fragmentary elevation and cross-section as taken along line X-X of FIG. 9.

Before proceeding with a description of the invention, a brief glance at the prior-art car truck fragmentarily illustrated in FIGS. 1, 2, and 3 is made in order to note several features respecting which improvements are made in the embodiments of the invention illustrated by FIGS. 4 to l0. For example, the friction wedge springs 1 of FIGS. 1 and 2 are smaller in comparison to the load spring 2. Because the prior art bolster 3 and side frame 4 are not interlocked horizontally by the wedges 5, the bolster is equipped with lugs 6. This in turn requires that the columns 8 and 9 of the side frame be provided with notches 10 and 11 which accommodate the bolster lugs 6 when the bolster is removed from the side frame. These notches and notches 12 and 13 at the upper ends of the columns extend the beam length of the tension and compression members, respectively, across the bolster opening of the side frame with consequent reduction of side frame strength. The lugs 6 of the prior art bolster retain the bolster within the side frame during operation by engaging side surfaces 14, of the columns above the notches 10 and 11. Clearance between the bolster lugs and the columns define the lateral movement that the bolster may make relative to the side frame. In the limiting of such lateral movement, wearing away of metal occurs on the opposing surfaces of the lugs and the adjacent side surfaces of the columns thereby causing an expensive repair problem.

Leaving now the prior art construction as discussed above, and considering below a car truck in accordance with the present invention as illustrated in FIGS. 4 to 10, the embodiment of the invention as illustrated in FIGS. 4, 5, 7, and 8 is first described.

As shown in FIGS. 7 and 8, one of the two opposite end portions of the bolster is supported in one of two side frames 19, 21 by two groups of springs of different diameter seated at their lower ends on the bolster spring seat 22. The springs of `both groups are of equal length but differ in diameter so that the smaller springs 23 of the one group t concentrically within the larger springs 24 of the other group. As shown, each of the larger springs 24 has disposed within it a spring 23. The number of smaller springs 23 exceeds the seven larger springs 24 by two. Each concentrically associated pair of springs 23, 24 may be considered a coil spring unit. The two smaller springs 23 not received in a unit are disposed along a central longitudinal plane N-N of the bolster for more efiicient utilization of the available load spring seating area in meeting load capacity load requirements of the car truck.

As shown by FIG. 8 and the right side of FIG. 7, the upper seat for the assembly of springs 23, 24 is defined by the undersurface 26 of the bolster and the undersurfaces 27 and 28 of a pair of friction wedges 31, 32. Wedges 31, 32 have sufficient undersurface area to completely cover the upper end surfaces of coil units 34 and 35, each of which comprises a pair of springs 23 and 24. As shown in respect to wedge 32, each wedge has a corner portion overlying the adjacent spring unit. For example, corner portions 36 and 37 extend over a small portion of the spring 24 of the spring units 38 and 39. In a similar manner, the wedge 31 is related to associated spring units.

While the spring unit centered under either wedge primarily activates the wedge in its snubbing function, the adjacent spring units in supporting relationship wth corner portions of the wedge assure that the wedge will always be supported within its respective recess as provided by both the bolster and the side frame column, and that the bolster and the side frame will thus be interlocked from separating in the longitudinal direction of the bolster. For example, any two of the three spring units supporting a wedge could be inoperative and the third unit would maintain the wedge in its recess. However the wedge, bolster, and side frame are originally manufactured to dispose the undersurface of the wedge at a level at least as high as that of the bolster undersurface 26. It is understood, of course, that, as the wedge and the wedge-engaged surfaces of the bolster and side frame become worn, the wedge will rise out of the plane of the bolster undersurface to retain engagement only with the spring unit centrally thereunder.

So that the snubbing system is always slack-free, the springs under the wedges preferably have a slightly greater free height, e.g., a half inch greater, than springs under the bolster spring seat. For example, if the springs under the bolster seat 26 are of the standard free height of 9%6 inches, then the springs under the wedge are provided in the next standard free height of 95/8 inches provided by the spring manufacturers.

In adherence to the present invention, the end contour of the bolster 20 is without lugs and preferably rectangular with its width slightly less than that of the straightsided bolster opening 41 to enable the bolster end portion to be withdrawn at any level providing the Wedges 31, 32 are removed. The opposite vertical sides of the bolster opening are defined on the one side by column flanges 43 and -44 and on the other side by column flanges 45 and 46. These flanges are vertically rectilinear and join with the side frame tension member 48 and the side frame compression member 49 in fillets for maximum side frame strength. This mode of construction has the effect of minimizing the effective width of the bolster opening and maximizing the effective width of the bolster received in the opening in order to achieve high strength in both the bolster and side frame. Another advantageous aspect of the present truck design is that, as may be plainly seen in FIGS. 7, 8, 9, and l0, the flanges of each column and the vertical transverse wall which connects the flanges, eg., wall 51, defines a recess in the column which becomes a substantial portion of the pocket in which the wedge is housed. Hence, an appreciable portion of the wedge is housed within the column outside the periphery of the bolster opening to dispose also a portion of the undersurface of the wedge within the column recess.

By this structural feature, an important advantage of the invention is realized in that the designer is no longer conned to the area immediately under the bolster for distribution of the load springs on which the bolster is supported. As FIGS. 7 to l0 show, the load springs under the wedges are disposed slightly outside the lateral confines of the bolster and, at the option of the designer, may be disposed even further outwardly. Hence, the present invention provides a mode of obtaining greaterseat area with respect to the longitudinal direction of the side frames.

A further advantageous aspect of the invention is that the wedges provide flanges which are extensions of the bottom wall of each Wedge forming a downward-facing spring seat of sufficient size to receive a full sized load spring employed in the car truck. Noting Wedges 31 and 32, for example, the bottom walls 53, 54 are extended by flanges 55, 56, respectively, in order to provide adequate spring seat area for respective double spring units. In providing the wedges with such flanges, the wedges must be constructed of suflicient width in the longtitudinal direction of the bolster to correspond to increased dimension afforded by the wedge flange in the transverse direction of the bolster. Hence, it is to be noted that the wedge is necessarily of wider construction than those heretofore employed in the Barber type car truck.

Correlating to the flanged construction of the friction wedges is the modified bolster construction that the Wedge flanges entail. In the two modifications of the invention presented by FIGS. 5 to l0, the bolster portion which extends into the bolster opening of the side frame in each case has an undersurface functioning primarily as a seat for the load springs. As viewed in FIG. 8, this undersurface and the lateral surfaces of this bolster portion are deeply recessed to provide major portions of the wedge pockets and the inclined bolster surfaces 5S and 59 of each wedge pocket.

As special construction in accordance with this invention, the undersurfaces of the bolster are indented to a further extent by a shallow recess forming a portion of the wedge pocket extending from the inclined bolster surfaces thereof toward the central longitudinal vertical plane of the bolster. This portion of each wedge pocket provides space for the flange of each wedge. Such recesses are of a depth exceeding the thickness of the flange such as to provide vertical clearance and allow adjustment upward of the Wedge as a result of wear sustained by various relatively moveable surfaces of the friction system while maintaining sufficient contact with the primary snubbing surface 66 of the column as provided by a wear plate 67. As the wedges of the car truck may be identical in construction, wedge 32 as shown in FIG. 5 is exemplary of the wedges of a car truck according to FIGS. 7 and 8.

A car truck of modified design is shown in FIGS. 9 and 10. It differs from the embodiment of FIGS. 7 and 8 primarily in (1) the arrangement, number, and aggregate capacity of the load springs, and (2) in the design of the friction wedges. 'I'he spring group thereof may comprise springs of the same sizes as used in the car truck of FIGS. 7 and 8. The seven spring units of the earlier described embodiment may be grouped in a tighter cluster to exclude the two small springs 23 as shown in FIG. 7 to make room for four of the small springs 23 in each of the four corners of the generally rectangular spring seats afforded by the side frame and the bolster as shown in FIG. 9. The arrangement of FIGS. 9 and l0 enables a car truck of the general dimensions of the one shown in FIGS. 7 and 8 to be constructed to somewhat greater capacity.

The wedges 71, 72 may be of identical design as shown. In conformity with the invention, they comprise anges 73 and 74 which permit construction of the bottom walls of the wedges to any size necessary to provide a spring seat adequate for covering coil spring units of one or more springs of any size desired without substantial weakening of the bolster. However, wedges 71 and 72 have upper flanges 75 and 76, respectively, which distinguish them in an essential manner from the wedges 31, 32 of the earlier described embodiment.

Because the arrangement of the bolster and side frame as taught by this invention disposes a portion of the wedges in outward relation with the periphery of the bolster opening, it is possible to achieve a heavier and wider cross-section of the bolster in that portion thereof which is recessed for the friction wedges. Comparing FIG. 10 and FIG. 8 it may be seen that the bolster 80 in FIG. 10 has a top wall 77 of full bolster width between the points 78 and 79. Other dimensions being comparable, such a result is achieved by, e.g., sloping the wall 81 of the wedge 72 at a less steep angle with respect to bottom wall 82 than the analogous wall 60 of the wedge 32 so that the width of the top wall 77 may be extended to full width of the bolster between the wedges. However, such an expedient results in a shortened vertical wall of the wedge where this wall is not extended by an upper flange. Hence, the wall 84 is upwardly extended by a ange 76 to provide a friction surface on the wedge of sufficient length for desired snubbing action. Because of the recessing of the columns to provide the primary friction surface 85 brought into play during snubbing operation, the ange is conveniently disposed within the column recess outside the full width of the bolster and, preferably, outside the periphery of the bolster opening.

As the slope of the wedges with respect to the bolster controls the friction force between the wedges and the columns, construction of the wedges 71, 72 and the bolster V80 as described above, indicate freedom of the designer to employ any desired bolster-to-wedge angles which produce the wedge-to-column snubbing forces desired. The structure of wedges 71, 72 further teaches freedom of the designer to extend the vertical column engaging surfaces of the wedges upwardly or downwardly relative to the body of the wedge by anges =in order to achieve greater areas, hence reduced wear rates, and to achieve proper disposition of the sloping surface of each wedge relative to its vertical column-engaging surface in order to transmit a horizontal force component along a desired axis to the vertical column and wedge surfaces in frictional engagement.

In addition to the advantages just indicated, the design of a car truck as herein taught lends itself readily, as has been pointed out before, to recessing of the columns to any extent desired to dispose portions of the spring acting on the wedges within the columns themselves to thus extend the spring seat of the side frames longitudinally of the respective side frames.

The design features entailed in the friction snubbing system hereinabove described provides a clear departure from the conventional Barber truck design to achieve greater snubbing capacities, larger spring seat areas, and hence greater load capacities within design standards required by the Association of American Railroads (A.A.R.).

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention of excluding such equivalents of the invention described or of the portions hereof as fall within the claims.

What is claimed is:

1. In a car truck:

(A) a side frame having columns at opposite sides of a bolster opening and an upward-facing spring seat along the bottom of the opening, said columns defining parallel opposed vertically rectilinear surfaces at opposite sides of the opening;

(B) a bolster having an end portion disposed in said opening defining a downward-facing spring seat, said end portion having at each side an inclined substantially rectilinear surface sloping toward a vertical longitudinal median plane of the bolster in dihedral relation with the adjacent one of said column surfaces to define a wedge-receiving pocket, said downward-facing spring seat being vertically indented to define a shallow extension of each pocket projecting away from said sloping surface toward said plane;

(C) a friction wedge disposed in each pocket against the pair of said surfaces defining the pocket, the wedge having a bottom surface approximately flush with said downward-facing spring seat, said bottom surface being partially defined by a flange of the wedge projecting horizontally into said pocket extension, said flange in operative position having vertical clearance with any surface defining said pocket extension; and

(D) a group of coil springs of approximately equal diameter and height disposed between said lower spring seat and the combination of said upper spring seat and the bottom surfaces of the wedges;

(E) each of said bottom surfaces including the portion thereof defined by said ange, and one of said coil springs being in vertical alignment and of relative size to disposed said bottom surface in covering engaged relation with the end surface of said spring thereunder.

2. The truck of claim 1 wherein:

said vertical column surfaces are recessed with respect to other column surfaces defining the side sections of the periphery of the bolster opening, said other column surfaces extend vertically rectilinearly from an upper compression member to a lower tension member of the frame, and said bolster portion is horizontally traversible through the bolster opening at any level, in the absence of said wedges.

3. The car truck of claim 1 comprising:

a second group of coil springs of approximately the same height and of smaller diameter than the firstnamed springs, each spring of the second group being received in one of the first named springs, the springs of each of said group being of uniform size.

4. The car truck of claim 1 wherein:

(A) said wedges each comprise converging walls defining outer surfaces in substantially mating engagement with a pair of said dihedrally related surfaces, the wall of said Walls engaging each of said vertical column surfaces extending vertically beyond the line of intersection of the planes of said outer surfaces to provide a second flange of the wedge defining an upper extension of said wedge surface which engages each vertical column surface; and

(B) said vertical surfaces of the side frame are in recessed relation with the periphery of the bolster opening to an extent disposing said second ange generally outwardly of said periphery.

S. The car truck of claim 1 wherein:

(A) the top wall of said bolster portion extends the full width of said portion and said vertical surfaces of the side frame are recessed relative to the periphery of said opening; and

(B) said Wedges each comprise converging walls delining outer surfaces in substantially mating engagement with a pair of said dihedrally related surfaces, the top portion of each said walls engaging each of said vertical column surfaces extending vertically beyond the line of intersection of the planes of said outer surfaces to provide a second flange dening an upper extension of said wedge surface engaging each vertical column surface.

6. The car truck of claim 1 wherein:

(A) said vertical column surfaces and other column surfaces at each side thereof define a recess for partly receiving one of said wedges within each column outside the periphery of the bolster opening;

(B) said lower spring seat defines the lower extremities of both column recesses; and

(C) said springs in alignment with said wedges are partly received in said column recesses.

'7. The car truck of claim 1 wherein:

(A) the side frame has an upper compression member and a lower tension member, each column comprises a pair of spaced rectilinear anges joining with the tension and compression members between which one of said vertical column surfaces is recessed with respect to the bolster opening, said llanges of both columns defining opposite portions of the periphery of said opening;

(B) said bolster portion comprises side walls spaced at close proximity with said flanges for passage of said bolster portion in an endwise direction at all levels within said opening;

(C) said flanges of each column are spaced for a wedge width providing an undersurface of each wedge enabling said undersurface to function as a spring seat entirely covering the spring in vertical alignment therewith and the springs of said group are of uniform size.

8. The car truck of claim 7 comprising:

(A) seven springs as said group of springs;

(B) a second group of coil springs of uniform size and of the same length as the first group but of smaller diameter, certain springs of the second group being received in a corresponding number of springs of the rst group to for-m a corresponding number of double-coil units;

(C) said units, and other springs of the second group not included in said units, being disposed in an arrangement wherein each of three double-coil units of a central subgroup are generally centered with respect to a vertical plane extending lengthwise of the side frame, and two other subgroups are located symmetrically with respect to said plane at opposite sides of the rst subgroup, the two end units of the first subgroup being disposed under said wedges; and

(D) each of said other subgroups comprise one of said smaller springs disposed between the two doublecoil units of the same subgroup and in laterial juxtaposition with the middle double-coil unit of the rst subgroup.

9. The car truck of claim 7 comprising:

(A) seven springs as said group of Springs;

(B) second group of coil springs of uniform size and the same length as the first group but of smaller diameter, certain springs of said group being disposed inside a corresponding number of springs of the rst group to form a corresponding number of double-coil units;

(C) said units, and springs of the second group not included in said units, being disposed in an arrangement wherein each of three units form a central subgroup generally centered with respect to a vertical plane extending lengthwise of the side frame, and two other subgroups are located symmetrically with respect to said plane at opposite sides of the first subgroup, the two end units of the rst subgroup being disposed under said wedges; and

(C) each of said other subgroups comprising two units included in a circle of six units surrounding the center unit of the `first subgroup, and two of said smaller springs in each of said other subgroups being disposed to engage corner portions of the spring seats.

References Cited UNITED STATES PATENTS 2,169,715 8/1939 Webb 10S-193 2,571,519 lO/l95l Barber 10S- 197 2,873,691 2/1959 Guins 10S-197 2,797,914 7/1957 Barber 10S-197 2,953,995 9/1960` Baker 105-197 3,072,076v l/l963 Warnock 10S-197 2,065,992 12/1936 Barrett i 10S-197 ARTHUR L. LA POINT, Primary Examiner HOWARD BELTRAN, Assistant Examiner U.S. Cl. X.R.

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