US2598359A - Car truck - Google Patents

Description

3 Sheets-Sheet l May 27, 1952 R. B. coTTRELL CAR TRUCK Filed Aug. 22, 194'? May 27, 1952 R. B. coT'rRELl. 2,598,359

CAR TRUCK Filed Aug- 22, 1947A s sheets-sheet 2 INVENToR. 5 joezif Cyoe/Z May 27, 1952 R. B, coTTRELL CAR TRUCK 3 Sheets-Sheet 3 Filed Aug. 22, 1947 INVENToR. jozef Coffre/ Patented May 27, 1952 UNITED STAT CAR TRUCKl -Robert B. Cottrell, Chicago, Ill., assigner Ato American Steel Foundries, Chicago, Ill., a corporation of New Jersey Application Augus't 22, 194'?, Serial N o. 770,063

'support a railway car truck bolster.

Another object of the invention is to provide a bolster-supporting hydraulic spring group with desirable snubbing characteristics to prevent the development of synchronous bolster oscillations.

In this connection it is also the object of this invention to provide .a simple and eiiicient 'hydra'ulic spring group designed for special application to a railway car truck side frame for use as bolster-supporting spring means.

A further object of the invention is to devise hydraulic spring means such as described, capable of accommodating tilting movements of the side frame and bolster.

Another object of the invention is to devise a bolster-supporting resilient, hydraulic unit comprising snubbing or damping means to control bolster oscillations.

Another object of the invention is to provide novel cushioning and positioning means for the hydraulic spring unit.

These and other objects of the invention will be apparent from the specication and the drawings wherein:

Figure 1 is a fragmentary top plan view of a truck structure embodying one form of the i'nvention, the view being partly in section taken in a substantially horizontal plane;

Figure 2 is a vertical section of the structure shown in Figure 1 with the bolster and resilient support units shown in elevation;

Figure 3 is a view corresponding to Figure 2 but illustrating another form of Vthe invention;

Figure 4 is a side view of one of the resilient support units shown in Figures 1 'to 3 inclusive, the right half of Figure 4 being shown in elevation and the left half of Figure 4 being shown in longitudinal vertical section;

Figure 5 is a fragmentary top plan view of a truckA embodying another modification of the invention, with the side frame shown in section through the columns thereof; and

Figure 6 Ais a sectional view in the liue 6&6 of Figure 5 with the bolster shown in elevation.

Describing the Ainvention in `detail and referring rst lto the embodiment thereof illustrated in detail in Figures l and the side frame comprises a compression member "2, a tension 'member 4 and spaced columns 6, 6 merging therewith to define the bolster opening 8 -(Figure 2) centrally of the frame. V

The tension member 4, as best illustrated in Figure 2, is o'f box section beneath the bolster Yopening' with a bottom chord I2, inboard l'and outboard Walls 'lli and I 'a'n intermediate wall i8, and a top chord 20, said top chord'rbe'ing widened and formed with upstandin'g ir'iboard and outboard ange's 22 and 24 dening the spring seat 2,6 on the tcp 'chord '20.

A resilient pad 2l, such as rubber, is superposedon the seat 2S, the pad 'affording a resilient support for a pair of bolster-supporting hydraulic spring units, generally designated 28, 28.

Each unit 28, as best illustrated in Figure 4,

comprises an elongate cylinder block or casing Se provided with a plurality of spaced vertical cylindrical pistonchambers or openings 32, 32 open at the top of the block, said chambers 3,2, 32 communicating at their lower ends through passages or ports 36, 36 in the lower portion of the block with areservoir chamber 34 formed centrally in the block.

The block is provided with an opening 38 leading into the Achamber 34 for the admission of hydraulic duid 4B (Figure 4) into the chamber 34, it being noted that the liquid completely nils all the available space in the chambers A32, 32, the passages '36,j35, and chamber 3ft. The opening 3B is closed by a threaded plug 42.

Each chamber 32 is provided at its upper open end or mouth withA a pressure-tightl packing 44 bearing at its inner face against the step 46 in the associated chamber 32 and being secured in positionby means of a closure plug orgland 43 threaded into the block.

Within each chamber 32 is positioned a piston assembly, generally indicated 5t, comprising a stem or rod 52 slidable through the associated packing 44 and closure plug d.

The upper end of each stern is provided with an abutment or bearing member 54 threaded thereon, each member 54 having a spherical surface 5% on the top side thereof affording a rockable seat for an end of the bolster 58 extending into the bolster opening 3. The bolster is 'provided with inboard and outboard gibs or lugs en and |52` on each side thereof embracing the adjacent side frame column therebetween, thus interlocking the bolster with the side frame in conventional manner.

Shifting of the units 28 within the bolster opening is limited by lugs 59 on the bolster received within openings 51 in the members 54 and associated piston rods, thereby preventing contact between the units 28 and between each unit and the adjacent portions of the side frame to prevent damage resulting from contact between these parts under the severe vibrations encountered in railway service.

A piston head 64 is threaded on the inner end of each stem for reciprocation with the associated stem within the associated cylindrical chambers 32, 32 and is in tight engagement with the associated chambers 32 by means of packing G5 tted in a circumferential groove in each head; however, it will be understood that the heads do not function to compress the liquid in the block.

This function is performed solely by the stems which, as they are moved under axial load, that is, by downward movement of the bolster, into the respective chambers 32 in the block, displace the liquid, thereby compressing it, thus resiliently supporting the bolster. 'Ihe heads, through metering means provided therein, to be described, serve merely to damp or control the reciprocating movements of the respective piston assemblies and control the rate of compression to a certain extent although they principally serve to control the upward or rebound movement of said assemblies.

The metering means in each head comprises a one-way ball check valve arrangement, generally designated 68 (Figure 4), and an orince f indicated at 68, said orifice extending through the `head to the opposite sides thereof, the lower end of the orice being frusto-conical in form to reduce turbulence of the ow of the liquid therethrough, as will be readily understood by those .5

skilled in the art.

The valve arrangement comprises a bore lil (Figure 4) extending through the head, said bore being of reduced diameter at its lower end and affording a seat as at 12 for a valve element or ,E

ball T4, said element being urged against the seat by a spring 16 positioned in the bore and compressed between said element and an apertured abutment member or fitting 18 threaded in the enlarged upper end of the bore 18.

In operation, as the bolster descends, the piston assemblies are moved inwardly of the respective chambers 32, 32, thus causing the iiuid 4B to move from below the heads to above the heads through the orifices 68, 58 and valves B6, 6G in the respective heads, it being noted that the fluid passing through the bore 1U is under greater pressure below the head and unseats the element 'i4 by compressing the spring 16. The stems of the respective piston assemblies as they enter the associated chambers 32, 32 displace the liquid therein, compressing it and thereby affording a resilient support for the bolster. When the load is relieved, the fluid-exerting pressure on the piston assemblies causes them to move upwardly, rapid rebound of the same being prevented by the iuid entrapped between the top sides of the respective heads and the packing. It will be noted that on the extension stroke of the units, the fluid is metered only through the oriiices E8, 63 in the respective heads, the one-way valves 55, 65 being closed by the action of the springs i6, '13.

Referring now to the modification illustrated in Figure 3 wherein the same reference characters are applied to designate similar parts, the

tension member 4 is generally similar to that shown in the rst embodiment with the exception that the top chord 2G is relatively narrow, said tension member being of box section and comprising, in addition to the top chord, the bottom chord l2, inboard and outboard walls i4 and it, an intermediate wall i3, and opstanding inboard and outboard flanges 22 and 24 formed on the top chord 20 and dening the seatz therewith, upon which is superposed a resilient pad 21 affording a resilient support for a single bolster-supporting resilient hydraulic unit 28, which in all respects is identical with either of the units 28 described in the previous modification.

Referring now to the modification illustrated in Figures 5 and 6 wherein similar parts are designated with the same reference characters as in the first two modifications heretofore described. the block 13o is provided with piston chambers 132, |32, |32, each connected to a separate reservoir chamber i341 through a passage or port 13% in the lower portion of the block. The only dii ference between this modication and the two previously described is that each piston assembly operates independently of the other. With this exception the construction of the piston assemblies and their functions is the same as heretofore described in connection with the other two modifications.

It is to be understood that i do not wish to be limited by the exact embodiment of the device shown which are merely by way of illustration and not limitation as various and other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

l. In a railway car truck, a side frame with a bolster opening, spring means in said opening seated on said frame, a bolster supported by said spring means, said spring means comprising a pair of hydraulic units each comprising a cylinder block with spaced closed intercommunicating chambers containing liquid filling all the available space therein, and piston assemblies arranged for reciprocation within respective chambers, each assembly comprising a piston head disposed within the associated chamber in uidtight engagement therewith, a piston rod extending into said chamber and iixed to said head and in duid-tight engagement with said block, metering means in said head for restrictively transferring the liquid from one side of said head to the other side thereof within said chamber for controlling the movements of said assembly, said stem being movable under axial load with said head into said chamber with the stem only compressing said liquid, an abutment member on said stem presenting an arcuate surface seated against said bolster to accommodate rockable movement thereof, and interengaging positioning means on said bolster and said stern.

2. In a railway car truck, a side frame having a bolster opening, a bolster in said opening,

means in said opening between said bolster and side frame to resiliently support said bolster from said frame comprising a pair of hydraulic spring units each comprising a cylinder block with communicating chambers containing liquid completely filling all of the available space therein, stems extending into respective chambers and movable thereinto under load for compressing said liquid therein, a piston head on each stem in fluid-tight engagement with the associated chamber dividing the same into two axially spaced portions, a through kportin each head 'for metering Vtheliquid upon movement of said head from one side to the other side thereof, and a ball check vvalve in said head operable to move to its open position upon the movement of the associated head inwardly of the related chamber and to rnove to its closed position on the reverse movement of said head.

3. In a railway car truck, a side frame having `a. bolster opening, Va bolster in said opening, means in said opening between said bolster and vsidefrainie to'resiliently support said bolster comcylinder, each assembly comprising a piston head nslidable huid-tight engagement with the associated cylinder, a piston rod connected to said head vand adapted to compress said liquid upon movement into said cylinder, and variable metering means in said head for damping the movements of the associated assembly by metering said liquid through said head in a direction opposite the movement of the assembly.

4. In a railway car truck, a side frame having a bolster opening, a bolster in said opening, and kmeans in said opening between said bolster and side frame to Yresiliently support said bolster from said frame comprising a resilient hydraulic unit including 4a cylinder block with a pair of spaced cylinders, a liquid reservoir chamber in said block. ports communicating with said cylinders and said reservoir, liquid completely filling all the available space in said reservoir, cylinders and ports, a piston assembly in each cylinder, each assembly comprising a piston head in slidable fluid-tight engagement with the associated cylinder, a piston rod connected to said head and adapted to compress said liquid upon movement into said cylinder, and Variablev metering means in said head for damping the movements of the associated assembly by metering said liquid through said head in a direction opposite the movement of the assembly.

5. In arailway car truck, a side frame comprising tension and compression members, spaced columns merging with said members and defining a bolster opening therewith, a bolster in said opening, and a hydraulic spring group in said opening between said bolster and said tension member affording a resilient support for said bolster comprising upper and lower members, the lower of said members comprising chambers having all the available space illed with liquid, the upper of said members comprising independent stems adjacent said columns in rockable engagement with the bolster, each stem extending into an adjacent chamber for reciprocation therewithin and upon movement into said chambers being adapted to compress said liquid to achieve resilience, a piston head in each chamber connected to the associated stem for reciprocation therewith, and metering means in each head for metering said fluid upon movement of the associated stem to control the movements thereof and thereby the movements of said bolster.

6. A structure according to claim 5, in which the lower of said members is formed with communicating chambers.

7. A structure according to claim 5, in which iii) l6 the lower of said members is .formed 'with :individual chambers.

28. A structure according -to claim 5, in which the lower Vof vsaid members is formed vwith three individual chambers.

-9. In a railway car truck, a side frame having spaced columns, a bolster therebetween, a spring unit comprising a pair of blocks seated on vsaid frame lbetween said columns, each block having spaced interconnected cylinders, one disposed adjacent each column, a pistonin each cylinder in fluid-tight engagement therewith, a compressible hydraulic fiuid filling said cylinders, said pistons supporting ysaid bolster at opposite sides Yof its longitudinal l.center line to yieldingly resist relative tilting movement between the side frameand bolsterduring compression of said unit.

10. In -a railway car truck, a side frame with a bolster opening, a spring group in said opening,

a bolster seated on said group, said group-comprising a pair of hydraulic units each comprising a cylinder block with spaced intercommunicating chambers containing liquid filling all the available space therein, a piston assembly in each chamber, and comprising a stem movable under axial load into the associated chamber to achieve resilience by .compression of said liquid, and damping means on each stem for metering said fluid for controlling the movements of the associated assembly, said piston assemblies associated with each block being spaced transversely of said bolster 'and engaging the same adjacent opposite sides thereof. 1l. In a railway car truck, a side frame comprising spa-ced columns, a bolster therebetween,

. a spring unit comprising a block with spaced interconnected cylinders, Lone disposed adjacent each column, a piston in each cylinder influidtight engagement, a compressible hydraulic iiuid filling said cylinders, each of said pistons supporting said .bolster at one side of its longitudinal center line to yieldingly resist relativetilting movement between the side frame and ybolster during compression of said unit.

12. In a railway car truck, a side frame comprising spaced columns, a seat on the frame Abe tween said columns, a bolster above the seat, and a pair of spring unitsv on the seat affording resilient support for the bolster, each springunit comprising independent pistons adjacent the columns and iny rockable engagement with .the bolster, casing means on said seat comprising chambers receiving said pistons, and a compressble .fluid iilling said chambers for compression by said pistons.

13. In a truck, a frame with a bolster opening, a bolster in said opening, a spring unit between a portion of said frame at the bottom .of said opening and said bolster and supporting the latter, said unit comprising telescoping members, certain of said members comprising independent pistons disposed adjacent opposite sides of the bolster and the other of said members comprising a casing with chambers receiving said pistons, a compressible fluid filling said chambers for compression by said pistons, positioning means on said pistons and bolster, and abutment means on each piston presenting a substantially spherical convex surface affording a rockable seat for the bolster.

14. In a railway car truck, a side frame having spaced columns, a bolster between said columns, and a resilient hydraulic spring unit supporting said bolster from said frame, said unit comprising a block mounted on the frame and extending lengthwise from adjacent one column to adjacent the other column and comprising a plurality of cylindrical chambers disposed adjacent opposite ends of said block, a reservoir chamber in said block between said cylindrical chambers, a compressible iiuid lling said chambers, a piston in each chamber reciprocal therein for compressing the uid, each piston comprising a substantially vertical stem, a bearing at the upper end of the stem surrounding the same and having an arcuate top face engaging a at face on the bottom of the bolster, said cylindrical chambers communicating with each other through said reservoir chamber to equalize the load between said pistons and to distribute the forces resulting from compressing said fluid around the entire casing.

15. In a railway car truck, a frame comprising spaced columns and tension and compression members merging therewith, a bolster between said columns, and spring means supporting said bolster from said tension member comprising upper and lower elements, the lower of said elements extending from adjacent one column to adjacent the other column and comprising chambers including cylinders adjacent respective columns, the upper of said elements comprising stems eX- tending into respective cylinders, said chambers being illed with compressible liquid for compression by said stems upon the imposition of a load thereagainst, a resilient pad between the lower of said elements and said tension member for accommodating angling of said spring means with respect to the frame, and abutment means on said stems in arcuate face engagement with the bolster to accommodate angling between the bolster and said spring means.

. "16. In a truck., a side frame comprising spaced columns, a block supported on the frame and extending from adjacent one column to adjacent theother column and comprising chambers containing compressible fluid, means abutting said 'bolster and reciprocal Within the chambers of said block for compressing said uid to aord resilient support for the bolster and including independent pistons adjacent the columns and rockably bearing against the bolster at opposite sides of the vertical plane bisecting said bolster longitudinally.

17. In a truck, a frame comprising spaced columns, a bolster, a spring group between said columns supporting said bolster, said group comprising spaced hydraulic units seated on the frame adjacent the inboard and outboard sides thereof, respectively, each unit including a chambered casing extending from adjacent one column to adjacent the other column and containing compressible fluid, a plurality of pistons reciprocal in each casing for compressing sai-d fluid, said pistons being disposed adjacent respective columns and rockably engaging said bolster.

18. In a truck, a frame with a bolster opening,

a bolster extending thereinto, aspring group mounted on the frame in the opening and sup` porting the bolster and comprising a plurality of cylinder blocks spaced transversely of the frame and extending lengthwise longitudinally of the frame, each block including interconnected cylindrical chambers disposed adjacent opposite ends of the block, compressible iiuid in said chambers, a piston in each chamber reciprocal therein for compressing said iluid, the pistons at one end of said blocks engaging said bolster :at one side of the longitudinal vertical center plane thereof and the pistons at the other end of said blocks engaging the bolster at the opposite side of said plane.

19. In a railway car truck, a side frame with.

spaced columns dening a bolster opening, a bolster extending into the opening, a resilient group supporting said bolster from the frame in the opening, said group comprising a casing mounted on the frame and extending laterally inboar'dly and outboardly of said frame and extending longitudinally from adjacent one column to adjacent the other column, spaced chambers adjacent one side of the casing disposed at opposite ends of said casing, a chamber adjacent the opposite side of said casing disposed intermediate the ends thereof, compressible iluid in each chamber, a piston in each chamber reciprocal therein for compressing said fluid, a bearing on the upper end of each piston presenting a spherical top surface engaging a substantially flat horizontal surface on the bottom of said bolster, the bearings of the pistons in the nist-mentioned chambers engaging the bolster at opposite sides of a vertical plane bisecting the bolster longitudinally and the bearing of the piston in the second-mentioned chamber engaging said bolster at a point disposed within said plane.

ROBERT B. CO'I'IRELL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,911,330 Symington May 30, 1933 1,970,841 Cottrell Aug. 21, 1934 2,099,240 Sproul Nov. 16, 1937 2,241,418 Nystrom et al May 13, 1941 2,333,095 Dowty Nov. 2, 1943 2,333,096 Dowty Nov. 2, 1943 2,394,082 Light Feb. 5, 1946 2,397,640 Bingham Apr, 2, 1946 2,411,630 Lehman et al Nov. 26, 1946 FOREIGN PATENTS Number Country Date 350,260 France Oct. 25, 1905 352,361 France May 27, 1905

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