US2597909A

US2597909A - Snubbed truck

Info

Publication number: US2597909A
Application number: US776603A
Authority: US
Inventors: Carl E Tack
Original assignee: American Steel Foundries
Current assignee: American Steel Foundries
Priority date: 1947-09-27
Filing date: 1947-09-27
Publication date: 1952-05-27
Anticipated expiration: 1969-05-27

Description

c. E. TACK 2,597,909

SNUBBED TRUCK.

4 Sheets-Sheet l chf Z. @che May 27, 1952 Filed Sept. 27, 1947 M ay 27, 1952 C, E, TACK 2,597,909

SNUBBED TRUCK Filed Sept. 27. 1947 4 Sheets-Sheet 2 INVENTOR. Cafz/ c// C. E. TACK SNUBBBD TRUCK May 27, 1952 4 Sheets-Sheet 3 Filed Sept. 27, 1947 INVENTOR. CZZJJZ E Zc C. E. TACK SNUBBED vTRUCK May 27, 1952 4 sheets-sheet 4 Filed Sept. 27, 1947 JNVENTOR. Ccz'zZZ ZZzc// BY v Patented May 27, 1952 SNUBBED TRUCK Carl Tack,r Chicago, Ill.,-.=ass.ignor to American Steel Foundries;- Chicago,` I1l.,f-.a corporation: of

New Jersey Applicatiomseptember 27',y 1947,-'SeriallNo. 776,603

11 @lai-ms. l

This :invention relates to railway .cartrucks and :more particularly'to a friction devicejor damping oscillations of the truck' bolster .which supports the car body.

In .the prior art various trucks 'havejceenx proposed and a number have. been .placed inservice wherein bolster. oscillations .are dampedby frictiondevices associated with the bolsterfor `developing frictionto resist its oscillations. .Such

arrangements have been generally .successfulin eliminatingharmonic;action of the .bolster-:supporting springs and theresultant harmfulV effect Well known to those skilled in the art. However, one fault inherent in all such devices vheretofore proposed in the transmission `of vibrations,v from the truck frame to the bolster and the .structure supported thereby, due to the fact that :the static friction developed in devices such as those `heretofore used for damping purposes f is relatively great in order to afford satisfactory:` kinetic friction to prevent harmonic oscillationsaof vthe bolster-supporting springs.

'In other words, in prior art arrangements, whether the friction devicehas been mountedzon the frame for cooperation with thebolster .or has been mounted on the bolster for cooperation with the frame, severe vibrations have been transmitted from the frame to the bolster during periods when the bolster has vbeen static relative to the frame. This phenomena-has .beendue to the relatively great coeicient of static, friction inherent in such arrangements to afford `satisfactory kinetic coeiicient of friction. Reduction of thestatic coeicient of friction has heretofore been regarded as impossible due to the ccnsequent reduction of the kinetic coeicient toa h useless` value.

Accordingly, a primary object of the :present invention is to afford a friction device for damping oscillations of a railway car truck bolsterat av lower static coeicient of friction -than-has heretofore been possible.

Another object ofthe invention is to aforda friction device, such as above-described, having a static coeicient of friction not substantially greaterthan the kinetic coeilicient to afford satisfactory damping of bolster oscillations tat all times.

Still another object ofthe invention-is toireduce transmission of vibrations fromithe frame tothe bolster by affordingmeans-for absorbing such vibrations and also capable of Adeveloping a'suicient kinetic coefficient of friction'tozaiford satisfactory damping vof bolster oscillations.

Still another object of the inventionzisrto providexaifriction device, rsuch' as above-described, wherein Jthe static and Vkinetic: coecients Y of frictionn'are substantially equalto accommodate dampingiofzthe bolsterloscillations-ata uniform coeiicient of )friction throughout the bolster stroke.

.flhepforegoingand Vother objects and advantages. of the invention Willbecomeapparentfrom aiconsideration; of the following specification and the accompanying draWingsw-herein:

:Figure 1 is afragmentary sideelevation of: a .car '..truck embodying .the invention;

:,'Illigure 2..is;.a sectionalview on the line .2-2

yof'fliigiure .1 :With the-bolster shown iny sidejv elevation;

'.FigurerS' isL a fragmentaryutop plan viewof the bolster 2 and ,-iassociated friction devices with the side: framegshowninfsection through the columns thereof;

Figure 4 is a sectional View on the line 4 4 of Figure. 3;

Figure 5 is a sectional viewon the line 5 5 l Vof-ligure 3;

.l Figure 6 is a fragmentary side elevational View .1 lFigurev'lis afsectionalview ofthe line '1 -lof `Figure 6 with the bolster shown inside elevation;

Figure is-a fragmentary top plan view of the Abolster'shown-in Figures 6 and 7 With the side framev shownin .section through the columns thereof;y

`Figuresi9 .to 14, inc1usive,lllustrate the'novel friction .shoe.-utilized'in theY arrangement of Figures 6,150.58, Figure .9 being a front elevational viewofthe shoe, -FigurelO being a side elevational viewthereoffFigure. lllbeing a rear elevational view, kFigure .12 .being a "fragmentary'top plan =view,v Figure l13 being a. fragmentarylbottom planvieW, ,f and Figure 14 v:being .a fragmentary lsectional viewonthelline i3d-'|14 of,- Figure 10;

.Figures "15 to 18 illustrate a modification. of .the :shoe .utilized in` thearrangement :of .'.Figures y6 :to8,-.Figure.1f5'being= aside; elevational viewo'f thefshoer Figureslbeing a rear elevational view, Figure `1'7 ibeing A.a :fragmentary v top -plan view, .and-Figure lbeing a fragmentary `.bottomc plan view;-and

Figure'il l is aside-:elevational view of another modification of-rthef. shoe Y utilizedl in the :arrangement` offFigures 6y to 8.

One embodiment. of .my novel -truck arrangement is, shown iniFigures -I- toa 5 inclusive, ywhereinnthe'` side :Hamai-generally: designated f2, com- :prises tension '.and` .compression i members F4=and-f6 merging adjacent corresponding ends thereof with columns 8 dening therewith the bolster opening l wtih widened upper portion I2 (Figure 1). The tension member beneath the bolster opening is a box section with the inboard and outboard Webs l and |6 and the top and bottom chords |8 and 20 as well as the vertical reinforcing rib 22 disposed intermediate the walls I4 and |6. The top chord I8 is widened and formed with upstanding inboard and outboard flanges 24 and 26 defining a spring seat 28 upon which are seated a plurality of coil springs 30 aording support for the bolster, generally designated 32.

The bolster comprises the top and

bottom walls

34 and 36 and the spaced side walls 38, and a pocket 40 is formed in each side of the bolster,

said pocket being defined in part by the inboard and

outboard walls

42 and 44 offset respectively at 46 and 48 and merging with a rear wall 50 at the inner end of the pocket. Integrally formed with the inboard and

outboard walls

42 and 44 are the spaced ledges 52 and 54, said ledges presenting wedge surfaces sloping upwardly and' outwardly toward the adjacent column and engaged at 56 and 58 respectively with

wing portions

60 and 62 of a friction shoe, generally designated 64, said shoe comprising a top wall 66 affording a seat 68 for the upper end of a spring l0, the lower end of said spring being seated at 'l2 against the bottom wall 36 of the bolster.

Each friction shoe 64 also comprises a front wall 14 for engagement at 16 with a wear plate 18 mounted on the adjacent column 8. The wear plate is preferably one which has substantially the same static coefficient of friction as the kinetic coecient. Such a material having the following composition may be obtained by conventional curing at about 325 F. and under adequate pressure to produce the desired density:

. Parts by Material Weight Rubber 4. Phenolic Formaldehyde Resin 5.0 Cashew Nut Shell Polymer. 3. 0 Graphite 7. 0 Bakelite impregnated Asbestos W Y 70.0 Carbon Black 2.0 Barium Sulphate. 7. 5 White Lead 7. 5

Another such material is disclosed in United States Letters Patent No. 2,052,779, issued'September 1, 1936, to Harvey J. Lidkea and Ray E. Spokes. It will be understood that any desired friction material may be utilized wherein the static coeflicient of friction is not appreoiably greater than the kinetic coecient and preferably where they are substantially equal.

Each shoe also comprises a rear wall 80 offset at 82 to form a handlelike loop received `within a complementary offset 84 in the rear AWall 50 of the pocket 40, the loop 82 being aligned with openings 86 in the inboard and

outboard walls

42 and 44. It will be understood that a tool may be inserted into the openings 86 and may be engaged with the oifset portion 82 of the wall 80 whereby the shoe may be Withdrawn from engagement with the associated wear plate 18 during assembly and disassembly of the bolster and side frame.

As may be seen in Figures l and 5, the surfaces on the shoes are crowned from top tobottom thereof. It may also be noted that the bolster 32 comprises inboard and outboard guidelugs 88 and 90 at each side thereof for engagement with the inboard and outboard surfaces of the adjacent F., li)

column 8, the outboard lugs 90, as may be clearly seen in Figure l, being of less depth than the widened portion |2 of the bolster opening, whereby the bolster may be elevated therein and removed therefrom during a quick wheel change Without disturbing the supporting springs 3D.

Figures 6 to 8 show another embodiment of the invention wherein the constant coefficient friction material is carried by the shoe. In this embodiment the truck is generally similar to that shown in Figures 1 to 5 and comprises a side frame, generally designated |02, and a bolster |04 supported therefrom by springs |06 adjacent a column |08 integrally formed with the frame adjacent each end thereof to define a bolster opening H0 (Figure 6).

The bolster, as in the previously described embodiment, is a box-section member with a pocket I I2 in each side thereof containing spaced wedge surfaces H4 sloping downwardly from the adjacent column and engaging complementary wedge surfaces of a friction shoe, generally designated H6, actuated by a spring ||8 seated on the bottom wall of the bolster.

The friction shoe I I6 is shown in detail in Figures 9-14 wherein it will be seen that the shoe comprises a front wall |20 with a narrow up- Wardly extending projection |22 merging with a top wall |24 affording a seat on its under side for the before-mentioned spring ||8. The rear end of the top wall |24 is integrally formed with a diagonal rear Wall |26 having at its lower extremity an inturned portion |28 (Figure 10) defining a loop or socket |30 to afford convenient means for keying the shoe within the bolster, as described in connection with the embodiment of Figures 1 to 5.

At each side thereof the shoe ||5 is formed with a diagonal wall or ledge |32 connected at its upper end to the front wall |20 and to a gusset |34 (Figure 10) formed with the top wall |24. The ledges |32, as will be understood by a ccnsideration of Figures 6 and 8, are engageable with the complementary wedge surfaces ||4 of the bolster. Each diagonal wall |32 is connected at its lower end to the inturned portion |28 of the rear wall |26 which is formed with a gusset |36 at each side thereof reinforcing its connection to the ledge |32. Each ledge |32 is connected to the front wall |20 by a side wall |38 reinforced by a gusset |20.

A friction liner |42 is secured to the front surface of the wall |28 and is provided with spaced lugs |44 received within complementary openings in Athe wall. The liner |42 is preferably formed of a constant coeflicient friction material, such as that described in connection with Figures 1 to 5, and is bonded to the wall |20 by any desired thermal setting cement.

Referring again to Figures 6 to 8, it may be noted that the above-described construction of the friction shoe is such that the shoe-actuating spring ||8 is seated against the spring seat wall |24 of the shoe at a point above the top wall of the bolster |04, thereby affording aV spring of maximum capacity. This feature'as above-noted, is accommodated by the extension |22 of the front wall |20 of the shoe.

Referring now to Figures 15 to 1B,l a modified friction shoe, generally designated |50, is illustrated for use in connection with the arrangement of Figures 6 to 8. 'I'he shoe |50 comprises a front wall` |52 having an upwardly extending projection |54 integrally formed with a top YWall |56 affording a seat on its under side for the scribed. is secured to. the. front-Walle landcomprisesaneupwardlyiextending projection lilsoomf plernentaryato theproiection 154 .of e,.shee The projection All! is y'seouredby a bolt 5 H2 threaded.v .into 'the-projection invalidi tbozznortion of. the; .top vWall- ISG joined thereto. Beneath the v,bolts |12 .are a Apair ofA boltsf |14 thre ded through the-"frontwau |52 .andinto the. edges |64 adjacent the upper extremity thereof. fg-Beneathzthe bolts |14 vare :a naif of ab .ts H6 threaded. through; the frontwall .lland nto the sidewalls 1.6.6. It- ;may befnoted-.that-,by means ofthe above-,described arrangementtbe; .friction face. I 68.1s securelybolted'to theishoef ,|50 Joystud bolts passing through relatively thick sections ofthe shoe particularly designed@toaocommodate .this means of ,seouromont :Furthermore the friction face |68 is ooextensivewithth ntre front wall |52 including theextension-E |54` thereof, thereby affording a somewhat greater friction area than in the previously described shoe IIE.

Figure 19 showsanother modification of a frictionshoe designed for use in .thearrangement of Figures 6 to 8. The modicationofligure 19 is substantially identical with that shown in Figures 9 to 13 and corresponding parts are identified by corresponding numerals. In Figure 19.-each ledge. |32 is recessedy as at 200 to-receive a,.wedge face orliner 202. of` constant coeicientfriction materiaLsuch. as .that above described,A thea liner 202having lugs or. bossest204 projecting` inP the complementary socket withinl .the ledge. 32gand being bonded theretowithfany desiredther-mal settingfcement.

lt. may be noted. thatV the modification ofrEigure .19. is Vsubstantially .identical with that of Figures 9 to 14 except for the .provisionvoffthe wedge face 202 having a static coecient of friction not greater than the kinetic coefficient of friction and preferably about equal thereto for the purpose of preventing sticking of the shoe along the associated bolster Wedge faces as sometimes occurs due to the relatively high static coeicient of friction at that point where the wedge face 202 is not utilized. It will also be understood that friction developed against the Wedge face 202 during oscillations of the lbolster laterally thereof between the side frame columns is substantially constant.

It is to be understood that I do not Wish to be limited by the exact embodiments 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.

Iclaim:

1. A railway car truck comprising a side frame member with a column, a bolster member springsupported adjacent said column, said bolster member comprising top and bottom walls and spaced walls defining therewith a box section, a pocket in the bolster comprising a wedge surface sloping toward said column, a friction shoe actuator in said pocket in wedge engagement with said surface, said actuator comprising a spring ns. carried hereby, anothenmemberrsupported,by saidspringmeans. ands friction-means f ondamping rela-.tira uertical vmcmement between.x saidmembers-comprising@ friction: surface; fiXedwith respechto oneeoffthe members.;anotherffriction'surface carriedfby the othertmember. iandactuatingsmeansafor; urging saidiother surfaceintorengagement .withthef-rstg mentionedsurfacef said-.actuating meansr-com- Drsingaspring.meanscarriedby one-of; ther-.meme ber-stand operatively. connected to said ,otherasurg. face.;l the-,surface .of .onenmember being; formada-.of material having ,asstatc f coefficient :of ffriction whcntengagedwith the-surface ofthe other meme ber :notsubstantiallygreater than .thek-inetic-.cof

efcientof'- friction offsaid materialwhen engaged withgthe'1- llast' -mentioned surface, and ;.said'fsur,. faceszibeingethe.sole means,v .undernormalrcontiiv. tions for 5 frctona'lly e resisting relative Yvertical moyementbetweensaid members.

33. A'rai'lway car truck comprisingfasidefiame. memberawithspacedcolumnsgai holsters-member springesupported between .said-columns, andrfric-f` tionfmeans.. at.: each ,side of said.y bolsterfmember A comprisinga pair, ofrffriction .surfaces -carriedeby thebQISten-member .andi the .adjacentfcolumnfree spectively, wedge .meansyinterposed fbetweernone of said; surfaces Aand,therelatedmembenfin .wedge engagement lwith; the .latter,. and spring s. means carriedy- -onezofr themembers `under. compression againgt saidvwedge means f for urgingffsaid-Qsuna faces. into ngagement, Yone of ,saidfsurfacesibeing formedy` gmaterial having .astatic coefficient-mf friction-M henfengagedwith .the otherfsurfacegnot subs antiajllyg greater1 than the: kinetic, coefficient of, :-tion;;of;.sa i d-;.materialv whenrengaged vwith saidotherrsurface.

4. A truck, according to claim 3, wherein the Wedge engagement of said Wedge means and the related member is along surfaces, one of which is formed of material having a static coefficient of friction when engaged with the other surface not substantially greater than the kinetic coefficient of friction of said material when engaged with said other surface.

5. A railway car truck .comprising a side frame with a column member, a bolster member springsupported adjacent said column member, and friction means comprising a wedge in wedge engagement with one of said members along corresponding wedge faces having a static coeiiicient of friction not substantially greater than their kinetic coefficient of friction, said wedge and the other member having engaged friction surfaces, one of which is formed of material having a static coefcient of friction when engaged with the other surface not substantially greater than the kinetic coefficient of friction of said material when engaged with said other surface, and spring means carried by one of said members for actuating the wedge.

6. A railway car truck comprising a frame member, a bolster member spring-supported therefrom,and friction means for damping relative vertical movement between said members comprising a friction surface fixed with respect to one member, and a friction surface carried by the other member, one of said surfaces being formed of material having a static'coeificient of friction when engaged with the other surface not greater than the kinetic coefficient of said material when engaged with said other surface, said surfaces being the sole means under normal conditions for frictionally resisting relative vertical movement between said members, and means for urging said surfaces into engagement.

7. A railway car truck comprising a side frame, a bolster spring-supported thereby, a wedge face on the bolster sloping toward a friction surface on said frame, a friction shoe engaging said face and having a friction surface engaging said frame surface, and spring means carried by the bolster and engaged with said shoe for actuation thereof, one surface being formed of material having a kinetic coefficient of friction, when'e'ngaged with the other surface, at least equal to the static coefficient of friction of said material when engaged with said other surface.. A 8. A railway car truck comprising a side frame member with a friction surface, a bolster member spring-supported by said side frame member, a wedge face on said bolster member sloping toward said friction surface, a friction shoe engaging said face and having a friction surface engaging said frame surface, and spring means compressed between one of said members and said shoe for actuation of the latter, one of said surfaces being formed of material having a kinetic coefficient of friction, when engaged with the other surface, not substantially less than the static coefficient of friction of said material when engaged with said other surface. 9. A railway car truck comprising a sideframe member, a bolster member spring-supported by said frame member, a friction shoe, said frame member and shoe having a pair of engageable friction surfaces, respectively, and said bolster member and shoe having a pair of engageable wedge surfaces, respectively, slopin-g toward the friction surfaces and means carried by one of said members for urging said shoe surfaces against the bolster member and side frame membersurfaces respectively, one surface of at least one pair being formed of material having a static coefficient of friction, when engaged with the other surface of said one pair, not substantially greater than the kinetic coefficient of friction of said material when engaged with said other surface of said one pair.

10; A railway car truck comprising a side frame member with a friction surface, a bolster member spring-supported by said frame member, a friction shoe carried by said bolster member, and means for urging said shoe against said surface, said shoe and surface having engaged areas, one of which is formed of material having a static coefficient of friction, when engaged with the other area, not substantially greater than the kinetic coefficient of friction when engaged with said other area.

11. A railway car truck comprising a pair of relatively movable frame members, and friction means for damping relative movement therebetween comprising friction surfaces carried by respective members, one of said surfaces being formed of material having a static coefficient of friction not substantially in excess of its kinetic coefficient when engaged with the other surface, and means for urging said surfaces into engagement with each other.

CARL E. TACK.

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

UNITED STATES PATENTS Number Name Date 1,817,570 Latimer Aug. 4, 1931 2,052,779 Lidkea et al Sept. 1, 1936 2,147,398 Blunt Feb. 14, 1939 2,237,953' Webb Apr. 8, 1941 2,308,966 Saurer Jan. 19, 1943 2,348,942 Watson M ay 16, 1944 2,378,414 Light June 19, 1945 2,381,378 Brown Aug. 7, 1945 2,447,368 Schlegel et al Aug. 17, 1948 2,516,072 Piron July 18, 1950