US2936721A - Bolster damping arrangement for railway car trucks - Google Patents

Description

May 17 1960 c. w. wuLFF 2,936,721

BoLsTER DAMPING ARRANGEMENT FOR RAILWAY CAR TRucxs Filed July 1, 1957 s sheets-sheet 1 jz den il@ 7@ May 17, 1960 C, w, WULFF 2,935,721

BoLsTER DAMRING ARRANGEMENT RoR RAILWAY CAR TRUCKS Filed July 1, 1957 s sheets-sheet 2 I 'HIIIIIIIIZQIIIzz gIllmmII/ I; RIU.

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BoLsTER DAMPING ARRANGEMENT RoR RAILWAY cAR TRUCKS Filed July l, 1957 5 Sheets-Sheet 3 A I l lf WWHIIM. IHIHIIHIHAHHIHIII I|IU i cn w. Wulff, Elmhurst, nl., fassgnor to Holland Company, va corporation of .-Illin'ois Application July 1, 1957, Serial No. 669,368

Y 19 Claims. `(Cl. 10S-1.97)

This linvention .relates Vto a'bo'lste'r damping arrangement for controllingthe movement of 'a bolster 'relative .to its pnifd Salies supporting side frame and, more particularly, it is concerned A with. a high-strength bolster end construction which accommodates and cooperates with a novel form of friction-'producing system that acts upon the opposed 'verticalfriction surfaces provided on vthe side frame col- Y vmovement to permit them to maintain continuous flush engagement with the side frame;y wherein the control springs that load the 'blocks are free to .flex along vtheir entire .length in following the movements of the friction blocks.; and wherein the movable parts of thea .friction system 'are retained compressed for handling, shipping, andinstallation of vthe bolster.

' Briey, this is accomplished by providing straightsided, longitudinally and transversely extending 'vertical walls inthe ends of the bolster with the walls extending between the usual top and bottom walls of the bolster .topform large-sized internal Ahousings arrangedV in back- `-'tQ-l: ack Vrelationship and .reinforcing the jbols'ter ends. l.Each -housing -re'ceives a frictiongblock with a controlled x,clearance to permit vthe rdesired -controlled- Vor klimited floating offthe' friction block for maintaining flush con- -tact with the friction .surface on vthe side frame columns.

:The friction block and the transverse walls of the housing provide spring seats for vengaging vonly the end for. dead coils `of the control spring so that all vof `the live coils of th'e'sprin-g 4are completely free lto liex. This Vrelationship .not vonlyeinsures that the block will continuously :mainrtain; flush engagement with the r'friction surface on the -side'iframe, even Iduring moments-when lthe bolster and `side frame are :slightly Vout-of-scpia'ra but it also eliminates .the buildup of harmfulstress concentrations inthe control spring itself.

. Patented May 17, 19Go rangement Vaccording 'to the'inventon, with parts of "the truck broken away tov better illustrate the construction of the friction-producing apparatus and its housing;

Fig. 2 is an elevational view of one of the housings. as seen from its open outer end;

Fig. `3 is an enlarged, fragmentary top plan view through the housing portion of the bolster, with .parts broken away and sectioned;

Fig. 4 is la view corresponding to the yright half of Fig. `3 but Villustrating the parts compressed to yreceive a retaining key;

Fig. 5 .is la vperspective view of the. friction block oo nstruction and illustrates the seating relationship betweenr the `control spring and the` friction block;

Fig. 6 is a side elevational view of a forked-type tool for compressing the parts of the friction-,producing ap.-

.paratus to facilitate the insertion of the retaining key;

and

Fig. 7 is a plan sectional view corresponding to the `view at the right half of Fig. 3 and illustrating a Vmodi- .ed friction block construction.

YReferring now to Fig. 1, there is shown Va conventional side frame 10 of a freight car truck. The side frame includes an upper compression member 11, a lower tension member (not shown), and spaced side columns 12 that definera bolster opening 13 within which the truck bolster, generally designated 14, is received for relative vertical movement. -The bolster is supported on a plurality of springs 15, which rest upon springseats Y (not shown) at the bottom of the bolster opening 13.

The general arrangement of the bolster 14 is familiar and comprises top and bottom walls, numbered 17 and 18 respectively, and side walls 19 having the usual outboard and inboard .guide flanges 20 that cooperate with the side frame `columns 12 to restrain the bolster against endwise movement. A pair of internal housings 21 are formed in back-toback relationship at each-of the opposite ends of -the columns r12.

. 'A'novel `arrangement is provided'for `retaining the parts .ofthe friction system, andrthisfincludes a retention arm 'extending rearwardly Vfrom the middle ofy thef friction iblock fand through the center of the control spring to project Vthrough a central relief opening provided in the .transverse housing wall that wforms the lseat for the Vtion. The side walls 24 and 25. :are offset transversely `cox'rtr'olspring. The rear end 'of -the retention arm'is y slotted `to'fre'ceive a retainer key.

'Other objects Iand advantages of the rinvention will' esignate ilike' parts throughout the saine', 4gil. 'is-vr a-fragme'ritary side-elevational View of 'a ac'zc'ompanying drawings forming a 'part of this l grei'ght'car truckequipped with -a' bdlsterdampingar- .As best seen in Figs. 1, 2 and 3, the walls defining the internal housings 21 are preferably cast integrally with 'the bolster, and the "top and bottom walls* of the bolster serve as the top and bottom walls of `these housings. With this arrangement, the housings 'are of maximum size.

Each housing is defined by longitudinally extending in board and outboard vertical side walls 24 and 25, respectively, and a transversely extending vertical rearY wall 26 that connects the rside walls. All of these wallsrextend the full heightV of the'fbolster to rigidly connect the top and bottom bolster walls, and this arrangement presents a remarkably high-strength bolster end construe (seeFig. 3)'so Athat their outer ends form an enlarged housing'in-whichthe friction block 28'is disposed and so that their inner ends denea housing that accommodates the control springs 29 for free lateralflexing movement. The innerends of the side Walls are preferably formed with the usual inspection slots 27.

The preferred form of friction block is best seen in Fig. 5, and it comprises a flat front wall 30, portions of the periphery of which are formed with integral rear- 'wardly extending cornered guide wings 31, the lopposite` sides of which extend adjacent to and surround the spring seat surface provided Von the rear face of )the friction block. The guide wings give the block arnaximum `.depth A of 15/s, but as indicated at 32, Vtheportionso''tlre to accommodate large-diameter control springs.

wings adjacent to the control spring are bevelled to avoid conict with the active coils of the control spring.

According to the invention, a controlled clearance is provided between thefriction block and its housing. For example, in the disclosed form, the housing for the fric'- tion block may be Wideand 41/2 high,.while the corresponding dimensions of the friction block arel" less. This limited clearance arrangement between the block and its restraining housing permits a controlled or limited floating action of the block to enable the block `to tilt as necessary and maintain ilush engagement with the friction surfaces on the wear plates. Under certain running conditions, such as when the car is negotiating curves and one side of the truck tends to run ahead of the other or when the brakes are so sharply applied as to produce tilting of the bolster, the relationship between the side frames and the bolster becomes slightly out-ofsquare, and if the block is to maintain a full, flat-surfaced bearing engagement with the wear plate, it must realign itself within its housing. The controlled clearance concept of the present invention allows suilicient free-heating movement of the block to compensate for such out-ofsquare conditions.

The present arrangement is to be distinguished, however, from instances where the friction block merely h appens to be loosely mounted in its housing since, in the present case, the control spring is conned only at its opposite ends where the dead coils engage spring seats that are so arranged as to permit all desired free-ilexing movement of the active coils of the control spring. Thus, as

'the friction block adjusts in its housing, the control spring To permit this free ilexing, the ends of the guide wings of the friction block are bevelled, as mentioned previously, to prevent contact with the active coils at the outer end ofthe control spring while at the inner end of the control spring, this concept is carried out by providing an upwardly facing arcuate support flange 34 that fixes the position of the dead end coil of the control spring Z9, which actually seats against the rear transverse wall 26. Preferably, the flange includes an outwardly extending ramp 35 that facilitates .the insertion and positioning of the control spring. Attention is directed to the fact that at all points, the internal housing provides suicient clearance to avoid contact with the active tcoils of the control spring.

As described thus far, the invention contemplates a floating friction block loaded by a control spring that is free to ex along its entire length, with the parts being mounted in internal housings of maximum size in orldler e larger the control spring, the lower its stress and, hence, the longer its life. Further, the greater the spring diameter, the greater is the bearing area that is subjected to `spring pressures and, hence, the more uniform are the resultant pressures. Another advantage accruing from a oating friction block arrangement is concerned with the fact that the bolster-damping action does not come into play during certain low-energy shocks which projduce only very limited vertical movement of the bolster.

UnderV normal running conditions, a limited clearance, as indicated at the region 36 in Flg. 1, will exist between the top of the friction block 28 and the underneath surface of the top Wall 17 of the bolster; and when low-energy shocks depress the bolster against the cushioning action of the springs 15, the bolster will move down independently of the friction block so long as the bolster movement does not exceed this limited clearance; therefore, all such bolster movements will be cushioned only by the springs 1S and no shocks will be delivered to the car as would be the case if the friction-damping system were brought into play immediately.

While the principles of the invention may be embodied in a bolster-damping arrangement that utilizes an adjustable spring seat, such as shown in co-pending application, Serial No. 564,294, filed February 8, 1956, now Patent No. 2,896,550, the disclosure of which, to the extent it is not inconsistent herewith, is specifically incorporated by reference, it is preferred to embody the invention in an arrangement wherein the parts of the friction-producing apparatus are retained in compressed condition during installation of the bolster by a suitable retaining element which holds the friction block in a retracted positionagainst the expansive action of the compressed control spring.

In this preferred form of the invention, the friction block includes an integral rearwardly extending central retention member 38, with the retention member projecting through a relief opening 39 formed in the rear transverse wal1'26 of the housing. `It will be noted from an inspectionof Figs. l and 3 that the relief opening provides a substantial clearance for the retention memb'er to accommodatethe tilting movement of the friction block. This central retention arrangement utilizes the otherwise dead space at the center of the control spring so that the size of the control spring need not be reduced to accommodate the retaining arrangement. Furthermore, the retaining member itself may be of appreciable size and, hence, of great strength.

In addition to the above advantages, an axially positioned retention member'directsv the forces of retraction along the axis of the control spring to produce uniform retraction of the friction block and thereby eliminate tipping of the friction `block and reduce the actual distance and, hence, effort, required to realize complete disengagement between the friction block and its wear plate. Also, olf-axis bending stresses on the control spring are avoided and this also increases control spring life.

At its rear end the retention member 38 is provided with a horizontal slot 40, dened by a bevelled rear surface 41, so that the retaining key 42 engages only the peaked mid-point of the surface 41 and thus acts directly along the axis of the control spring. As shown in Fig. 4, Ithe retaining key may be provided with a wedge-shaped leading edge 43 to permit the key to be sledge-driven into place. An alternative and preferred manner for retracting the friction block is to employ the fork-shaped tool 44 shown in Fig. 6, which may be used for reti-'acting the block suiciently to-permit the retaining key to be inserted manually. For this purpose the retention Amember 38 is provided with vertically extending nubs 46 and the transverse rear Wall 26 is cast with the upper and -lower fulcrum projections 47,V best seen in Fig. 1, so that the arms 48 of the retraction tool will straddle the end-of the retention member as the tool `is inserted into the position shown in Fig. 4. The use of the retainer tool has'the advantage that it eliminates the necessity of driving the retainer keyl 42 with a sledge. This is not only anunpleasant task, but it subjects the key and retention member to unnecessary damage and may cause failures at inconvenient times and locations.

The central retention member 38 of the friction block, while preferably integral, could, of course, be formed separately and rigidly aixed to the friction block by a threaded connection or by welding or by a suitable pinning arrangement. Alternatively, the retention member and friction block could be connected through a ball and socket connection, and this would allow free movement of the friction block relative to the retainer, in which case the retainer may be arranged for a sliding lit-inthe beseitigt ferred form of ythe invention 4is for the purpose of complying with section 112, Title 35., of fthe U.S. Code.

l. `:Ina railway ca'r `truck :including a side 'framehaving longitudinal-ly spaced columns providing opposed vertical friction .surfaces'anda bolster resiliently supported Ebetween `said Vcolumns Pand having side walls facing said surfacessaidbolster being provided with 4opposed internal housings opening 'outwardly toward said friction `surfaces to .form aligned :openings in saidfside Walls, said internal housingsk each receiving ia controlr spring :and a :friction blockV withfhe control springs Aurging the friction blocks through said aligned openings :into engagement with said friction surfaces; said .internal housings each being formed f by4 transversely spaced, longitudinally extending -inboard and outboard sidewalls offset away from eachother adjacertftheirv outer lends, and a transversely extending rear wall formed with a spring seat for said control springand arelief opening snrrounded vby and centered in said spring seat, said rear wall connecting vsaid housing sidewalls,

each Vof said frictionblockshaving a spring seat for the outer end V'of its :control springV and vincluding `a 'rearwardly projecting central'retention member telescoped through said central spring to vproject through said .relief opening with vthe Vrearmost portion of said .retention member .hav-- ing a retaining slot extendingtransversely therethrough and cooperatingwith a-'retaining key that is gripped between the rear of said slot and said transverse rear wall to retain the friction block. y

` 2.i Ina railwaycar truck including aside frame having longitudinally spaced'colurnns providing opposed Vvertical friction surfaces yand a bolster resiliently supported between-said columns and having-side walls facing said surfaces, said bolster being provided 'with opposed internal housings opening outwardly toward said friction surfaces |to form aligned openings in said side walls, said interna-l housings each receiving a control spring and a friction block with the control springs urgingthe friction blocks through said aligned openings into engagement with said friction surfaces; said internal housings each being formed by transversely spaced, longitudinally extending inboardY and outboard side walls offset away from each other adjacent their outer ends, and a transversely extending rear wall connecting said housing side walls and forming a Vfriction block, said separate spring seat and vsai n 'producing apparatus Arin veach housing, each apparatus in cluding a control spring and 'a .at-faced'frictio'n block with 4thecoritrol springs yurging the-friction 'block'sthrough said aligned openings :into :fiat-faced engagement with seid frictionV facesgthe improvement wherein nach` housing is defined by -a transverse rear wall formed with a central relief opening'and each friction block .includes ya rear wardly Vextending 'central 'retention member telescoped through said control spring and :having its .rearmost pon tion 'projecting through 'said relief opening and formed with a retaining slot, and 'a retaining :keyiin each 'slot and gripped 'between Athe rear fend of .fits vslot and 4the rear surface of the adjacent transverse rear wall to retain-each frictionblcch f 4. The arrangement of claim 3 wherein the .rear surface of each 'transverse wall "carries vertically spaced ttul;- crum projections outboard of said relief opening and ea'ch retention `member "carries 'upper and :lower external nubs at Sits rrear'end that fovela'p vertically vwith said projections.

' A5. Ina bolster damping arrangement for'use dn n frailway car 'truck that includes aside iframe :having'space'd columns providing ilat, opposed vertical friction `faces land a-bolster resiliently supported between saidficolumns and having side walls facing said columns, said bolster carrying opposed internal housings disposedbetwcen said Lfric Vtion faces and opening outwardly through said sidefwalis to :form aligned openings therein, and .fa friction-producing `apparatus in each housing, each apparatus including alicontrol spring and a fiat-faced friction block-.withfthe control springs urging the friction blocksfthrouglh .said

aligned' openings .into flat-faced 'engagement with .said fric tion faces; the vimprovement wherein eachihousing @is -de; lined by a transverse rear 'wall .formed with fra @cent-rater@ liefopening and a separate spring seat .for sai control spring `is disposed between said fcontrol..sprin` d block having complementary, spherically-shaped rfa is accommodating `universal relative pivotal".` .mo ent therebetween, said spring Yseat including a rearwardly -ii 'tending central retention member 'telescoped through said control springand having its rearmost portion projecting through said relief opening and formed with a retaining slot, and a retaining key in each slot and gripped be tween the rear end' of its slot and the rear surface Aof the adjacent transverse rear wall `to retain each separate spring seat.

6. Ina bolster damping arrangement for use in a railway car truck that includes a bolster having `side, top, and bottom walls, said bolster having each of its ends vresilently supported for vertical movement between side frame columns that dank the bolster opening, with a fric-` tion producing apparatus incorporated in' each bolster end for cooperative engagement with a vertical friction sur face provided on the adjacent side frame column, each bolster end having internal walls forming a housing that deiines a chamber opening outwardlyV through the' side wall of the bolster and each friction producingjapparatus including a control spring and a at faced friction block to said housings for limited floating movement therein,- V

each block providing a spring seat for the outer dead end vwith the control spring urging the friction block outwardv `ly-,through the chamber into flat faced engagement with '-the friction surface of the adjacent side frame column,

coil of its control spring with the housing walls providing columns providing at, opposed vertical friction facesl and a bolster resiliently supported between said columns and having side wallsfacing said columns, said bolster carrying opposed internal housings disposed between said friction faces and opening outwardly through said side walls to form aligned openings therein, and a friction- Vthe improvement wherein each housing has a transverse rear wall bounding the chamber dened thereby, said transverse wall having lan opening therethrough, each friction block includes a rearwardly extending retention member projecting axially through its control spring and having a rearmost portion 'projecting through said relief opening and terminating in Vstructure having an abutment facing toward said rear wall, said Vabutment cooperating with a retaining member that is gripped between the abut ment and said wall to retain the friction block retracted within its housing. l

7. A friction block comprising a substantially flat base plate having a at front friction surface of rectangular configuration a'nd'a rear spring seat surface, right-'angle guid wings at each corner of said block and extending along the marginal edges thereof to partially surround said jspring seat surface with opposed portions of adjacent ones of said wings being immediately adjacent said spring seat surface and being bevelled to slant towards said base plate, said block including a retention member projecting rearwardly from thecenter of said base plate and terminating in structure having a forwardly facing abutment that is disposed rearwardly of the maximum rearward extension of said wings.

`8; In a railway car truck of the type having a side frame providedl with a bolster opening defined in part by a side frame column: the combination with .a bolster hav'- ing. side, top and bottomwalls, said bolster being supportedin said bolster opening for cushioned movement therein',` one of the side walls of 4the bolster having an opening thereinat a point adjacent 'and facing said column; of 'friction-producing apparatus mounted on said one side wall for frictionally engaging the column to dampen movement of the bolster, said friction-producing apparatus comprising wall structure fixed within said bolster to form a housing rigidv with said bolster and having a'transverse wall at its inner end and having an open outer end in register with said wall opening, said transverse wall having a relief opening centrally therein, a coil spring in said housing and seated against said transverse wall atpoints surrounding the opening therein, a friction block`at 'the outer end of said housing and urged towards engagement with said column by said spring and including an inwardlyextending retention member projecting lengthwise through the spring and the vrelief opening and terminating in structure having an abutment facing `toward said/ transverse rear'walLand a retaining member engageable between said abutment and said y transverse i'ea' wall to retain Vthe friction block retracted within the housing.` Y

i 9.`In a'railway car vtruck of the type having a side frame provided with a bolster lopening defined in part by a side frame column: the combination with a bolster having side,l top'and bottom walls', said bolster being 'supported in said bolster opening for cushioned movement therein, one of the side ywalls of the bolster having an opening therein at a point adjacent and facing said colf umn; of friction-producing apparatus mounted on said one side Wall for frictionally engaging Vthe Vcolumn to dampen movement of the bolster, said friction-producing apparatus comprising Wall structure fixed Within said bolster to form a housing rigid with said bolster and hav-` ing a transverse wall at its inner end and having an open outer end in register With said wall opening, said transverse wall having a relief opening centrally therein, a coil spring in said housing and seated against said transverse wall at points surrounding the opening therein, a friction block at the outer end of said housing and urged towards engagement with said column by said spring, said friction block corresponding in cross-sectional shape to said housing and having an overall clearance dimension in all transverse directions within its housing on the order of IAG" for limited following'movement therein, said block including an inwardly extending retention member projectingllengthwise through the spring and the relief opening and terminating in structure having an abutment facing toward said transverse rear Wall, said transverse rear wall and said friction block each having structure providing a spring seat for contacting only the end coil at the corresponding end of the control spring, said housing providing lateral clearance for the remaining coils of the control spring to accommodate `free flexing movement between the ends of said spring as its follows the floating movement of its friction block, and a retaining member engageable between said abutment and said transverse rear ywall to retain the friction block retracted within the housmg. References Cited in the le of this patent UNITED STATES PATENTS 716,294 shauenberger Dec. `1'6, 1902 l1,866,762 Find July 12, 1932 2,366,913 Light Jan. 9, 1945 2,437,359 Pierce Mar. 9, 1948

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