US2024868A - Balanced draft gear - Google Patents

Description

. 17, 1935. w. H. MUssEY ET AL BALANCED DRAFT GEAR Filed May 25. 1931 2 Sheets-Sheet l Q [www o o o o omvllmmollm- Dec. 17, 1935. w. H. MUssEY ETAL BALANCED DRAFT GEAR Filed May 25, 1951 2 Sheets-SheeI 2 OOOOOOOOGOO@ I... up

@@OOOOOGIG@ vPatented Dec. 1.7, 1935.

PATENT oFFIcE BALANCED DRAFT GEAR William H. Mussey and Martin P. Blomberg, Chicago, Ill., assignors, by mesne assignments, to Pullman-Standard Car Manufacturing Company, a corporation of Delaware Application May 25, 1931, Serial No.4539,'128

2 Claims.r (Cl. 213-7) The invention relates to' draft and bufflng gears for railway cars designed to substantially equalize the application of bufllng stresses to the center sill upon opposite sides ofthe respective bolsters, whereby the sill under shock is stabilized about` the center pin and the concentration of bufling forces upon the center sill between bolsters and adjacent car ends,`is prevented.

'I'he invention further contemplates the division of forces applied to the center sill at one vbolster position between the two bolsters of the car underframe, whereby the forces transmitted to the side sill or car side by the rst bolster will be neutralized by the second bolster, thereby The invention has for its further object the provision of means in one embodiment of the invention whereby the normal series of spring units of one or more of the several spring groups may be automatically broken up in draft operations for utilizing lessmthanvall of the spring units of the series in the spring group or groups selected for that purpose and permit all of the spring units of the series comprising the groups affected, to be used in builing operationsl only.

The foregoing and other objects and advantages are achieved by the mechanism illustrated in the accompanying drawings, in which- Fig. 1 is a plan View in partial horizontal section showing one embodiment of the gear;

Fig, 2 is a vertical longitudinal section through the gear taken on line 2 2, Fig. 1, showing the spring groups lmounted between the spacer barrel and the respective follower stops on the center sill;

, Figs. 3 and 4 show respectively similar views of another and preferred embodiment of the invention, Fig. 4 being a section taken on line 4 4, of Fig. 3;

Figs. 5, 6, '7, andl 8, are vertical transverse sectional views through the gear and center sill.'

' side.

taken online 9 9, of Fig. 4, showing the draft.l yoke and the telescoping follower cylinders;

Fig. 10 is a similar view taken on line |ll l0, of Fig. 4, showing one form of means for pre s venting forward movement of the spacer barrel 5 under draft; and

Fig. 11 is a similar half sectional view taken on line Il ll, of Fig. 4, showing the type 'of follower plate used, and the relation thereof to the stops. 10

In draft gears heretofore generally employed, all of the gear parts have been positioned in the space between the'bolsters and adjacent car ends whereby all o f the blows delivered by the coupler were concentrated upon the adjacent portions of 15` the center sills. Since the center of draft is usually found below the neutral axis of the center sills supporting the gear, the resultant eccentric loading ofthe sills causes a vertical vdisplacement of the sillsdownwardly between 20 bolsters and adjacent car ends, and upwardlybetween the bolsters of the underframe.

The eccentric loading is especially marked in the center sill at the bolster structure in which f the neutral axis is' stepped up by the presence ofv25 of the center sill under buiiing operations. Such 30 *l upward thrust of the sill between the bolsters is communicated to the lading in the ear with resultant shifting thereof from simultaneous car movement under impact.

Under frames thus equipped with draft gears 35 mounted between bolsters and adjacent car ends only, transmitted the full stress of bufling to adjacent bolster and the center sill, whereby an undue proportion of such load was transmitted .by such bolster to the side sills or car 4o The difficulties enumerated are overcome by the placement f substantial portions of the gears at each end of the carupon opposite sides of respectively adjacent bolsters, to the end` that the forces of bufling transmitted to the 45 bolsters will be reduced by an amount corresponding .substantially to the capacity of the respective gear parts between the bolsters.-

'Ihus distributed, the forces generated are split up over a longer distance along the center sill, the eective columnbetween the nearest gear part at one end of the car and the bolster at Vthe opposite end being substantially shorter than that hitherto obtaining between such bolster and the gear positioned between the other the car, permitting a lighter construction of underframe with a corresponding reduction in cost of materials and Without impairing the strength of the structure. Such disposition 'of the gear parts and distribution of bufiing at isolated points on the center sill, promotes stability in the structure by overcoming the tendency of the sill to fulcrum vertically about the truck centers and admits of the use of center sills having areas well below the American Railway Association minimum requirement of 28 `square inches for the section.

As indicated in the drawings, I0 represents the center sill With its members spaced apart and connected by a cover plate II and extending from end to end of the car. The bolster structure is built up around the sill and comprises preferably a plurality of diaphragms I2 spaced apart upon opposite sides of the center if sill and connected at their inner endsto the webs of adjacent sill members and at their relspective upper and lower margins by top and bottom cover plates I3 and I4.extending across the sills, as shown in Figs. 1 to 6, and 9.

The relation between the sill members and bolster cover plates is further maintained by a filler casting I5 of substantially box section and secured to sill and cover plates by means of circumscribing flanges I6 on walls I1 of the casting, as best shown in Figs. 1 to 4. The walls of the casting are connected by" a base wall portion I8 resting upon bottom cover plate I4, as shown in Figs. 2, 4 and 6, and a cylindric web portion I9 immediately above the base plate and reinforced by radial flanges 20 extending between and further vconnecting the walls and cylinder, as illustrated in Figs. 1, 3

and 6. The cylindric wall I9 provides a bearing 2| for a spacing barrel 22 slidable therein for a purpose hereinafter to bel described, and functions to stiffen the bolster and sill assembly. 'Ihe upper side of the cylinder I9 is formed with a perforated socket 23 designed to receive the head and shank of a center pin 24 extending downwardly through corresponding openings 25 in the filler base I8 bolster bottom cover plate I4, and the center bearing 26.

As the bolster, sill and draft gear assemblies at the opposite ends of the car are identical, but one end assembly has been shown and but one described, the effect of the operation of one assembly upon the other being obvious.

. The bolsters are connected at their ends by side sill members 2l extending preferably-to the end sills 28 and by them connected to the center sill to insure rectilinear stability between longitudinal and transverse members of the underframe whereby stresses of builng may be distributed as contemplated from one bolster and draft gear assembly to the other. The center sill is fitted at its opposite ends with coupler 'carriers 29 for supporting drawbars 30 movably Iheld by draft keys 3I slidably mounted in slots 32 in the center sill.

The draft mechanism of the Invention is mounted between the sill members I0 and fore and aft of the bolsters, the gear divisions upon opposite sides of the respective bolsters being separated by spacer barrel 22 conforming in general outline to bearing 2| defined by the 5 cylindric wall portion I9 of the bolster filler casting I5 above noted. 'I he spacer barrel is formed at its ends with buing faces 33 and 34 designed for engagement 'with respectively adjacent gear yokes in front of and rearwardly 10 of the holsters, and is provided with registered slots 36 extending longitudinally of the casting in its upper and lower peripheral sides to receive the center pin 24. i

illustrated in Figs. 1 and 2, wherein the barrel 555 22 is provided with a lug 39 projecting downwardly from its underside and designed to engage one or more sides lof notch 48 in base ange I6 on the filler I5, the lug and notch being held normally interlocked under pressure 30 of spring units'4I of spring groups 42 and 43 in the rear yoke. As indicated in Figs. '1, 2, 7 and 8, the rear yoke is formed with its spaced arm portions 44 and end wall portions v-45 integral to provide` a housing for the series of spring $5 units 4I comprising group 42.

The yoke arms 44 are proportioned to Withstand pressure under builing shocks and formed with their opposing faces grooved `as shown at 46 to accommodate and retain circular rubber 40 spring units 4I -of the type illustrated in Figs.

1 to 5 inclusive, 7 and 8, comprising the core plate portions 41 and concentric rubber rings 48, the springs being entered in the yoke at a point adjacent the rear end Wall 45 through a pas- 45 sageway formed by enlarging the opening bevveen the yoke arms 44 adjacent the rear wall The rear yoke is further provided with rearwardly extending lug portions 49 to which is 50 secured an auxiliary housing portion 58 comprising a plate section bent U-shape with a pair of arms 5I secured at their free ends to respectively adjacent lugs 49 on adjacent yoke wall 45, and their opposite ends connected by a rear 55 Wall portion 52, and forming a support for the second spring group 43, as best `shown in Figs. 1, 2, and 8.

The spring groups 42 and 43 are held normally in compression respectively between folo lower 53 and.yoke front wall 45 and between follower 54 and rear wall 45 of the rear yoke, the respective followers having bearing against stops 55 and 56 on the center sill I8, as best shown in Figs. l, 2, 7 and 8, and since pressure 35' during bufling is utransmitted through the rear yoke and not at all by housing 50, the latter may be only of suicient strength to carry the springs and follower enclosed by it. The rear A yoke andattached spring housing 58 are oper- 70A ylo of the buing load caused vertical displacement of the sill about the bolster whereby that portion of the sill in front of the bolster would drop and that behind the bolster thrust' upwardly.` When a portion of the buiiing load is leccentrically applied to the sill at the draft stops 55 and 56 back of the bolster as shown in Figs. 1 and 2, these stops in effect, mark the ends of sill columns extending thence in opposite directions, the end of the shorter column yto adjacent bolster tending to rise and the contiguous end of the longer column to opposite bolster tending to droop under bufdng impact whereupon the forces are neutralized with the result that the sill columns are stabilized under shock and the car lading and truck springs freed of objectionable stressing, as before noted.

The gear mechanism of the same embodiment includes a front yoke member having forwardly projecting spaced ear pieces v6l) slotted to receive draft keys Stand forming integral parts of av yoke body comprising front, intermediate, and rear wall portions 6I, 62, and `l63, respectively, connected by arm portions 64, and together providing housings for spring group 65 and draft spring group 66. The yoke is slidably supported upon plate 61 removably secured to underside of center sill Il' by bolts 68. Since the yoke transmits theforce of bufling to spac-` ing barrel 22 in the bolster, the arms 64, as in the ca se of the rear yoke arms 44, are shaped to provide maximum section of material in the arms with portions adjacent intermediate vand end walls 62 and. 63 removed to receive spring units 4I of respective spring groups 65 and 66 and associated followers 69, 18 and 1I. Followers 69 and 18 normally engage draft' stops 'l2 and follower 1| will be normally free from adjacent draft stops 13 on the center sill for a purpose hereinafter outlined. The springs of these groups like those of groups 42 and 43 are held normally compressed within their respective housings. I

'Ihe spring group 66 alone will function in.

draft but is adapted to combine with the other spring groups of the series during bufllng operations, the remaining spring groups 42, 43 and 65, being inoperative in draft, during which4 periodthe front spring group 65 is shifted bodily and without distortion with the yoke walls 6I and 62, and follower 88, moving forward with the coupler 38. On the other hand,.the second spring group 66 will be' compressed vbetween follower 18 held by draft stops 12 dand companion follower 1I and rear wall 63 movable forwardly with the yoke.

'Ihe second spring. group 68 has been chosen for draft purposes primarily for the reason that its position provides a longer radius for the draft arm with arelatively small angularity foi"- a .given lateral movement of the coupler at the carrier 28. Conceivably, the lfront spring group 66 can be made the draft spring group of the gear by the simple expedient of positioning 'operation from draft to bufng stages or vice versa, during. the normal lag and surge of coupled cars in train movement, the draft spring group 86 is initially compressed an amount approximating that of the remaining spring groups combined. It becomes necessary then to permit such other spring groups to be severally compressed an amount substantially equal to the compression' of the draft spring before follower li engages the draft stops 13, the time interval thus required to equalize the compression in all of the springs being afforded by space ld. to permit the building up of the desired compression so that all of the springs will function uniformly in bufling. Duringl the initial stage of this operation, the second or draft spring group 66 will be shifted bodily with adjacent followers 18 and 1l for a distance corresponding to space 14 between follower li and adjacent draft stop 13. In the 20 preferred embodiment shown in Figs. 3, 4, 9 and 1i, the number of spring groups upon opposite sides of the bolsterhas been reduced but the groups themselves have been enlarged to seven spring units each to approximate the 25 capacity of the four spring groups of five spring units each and to permit correspondingly greater gear movement during buiing. 'I'he rear yoke comprises the head 35 having upper and lower rearwardly projecting lug portions 49 to which 30 is secured a housing portion comprising a plate section bent U-shape as in the case of the other f embodiment and provided with a pair of arms 5l secured Uat their free ends to respectively adjacent lugs 46 and connected by a rear wall portion 52, and forming a support for the rear spring group 15. During buifing operations the springs are compressed between head 35 of the yoke and follower 16 normally engaging adjacent draft stops T1 on center sill I8. The yoke is slidably supported on plate 18 removably secured to underside of center sill by bolts 19, as best shown in Figs. 3, 4 and 10.

Buifing shocks are transmitted to the spring group 16 behind the bolster by a coupler yoke member formed with forwardly projecting spaced ear pieces 60 slotted to receivedraft keys 3l and forming integral parts of a yoke body comprising front and rear wall portions and 8l, respectively, connected by arm portions 82, and 5 together. providing a housing for )associatedspring groups 83 and 8 4, the latter of which constitutes the draft spring in the assembly. The groups 83 and 84 are spaced by a pair of followers 86. and 86' normally engaging each 55 vother and the respective spring groups 83 and 84, to permit the functional union of said spring groups in bumng operations and theirvsepara- -tion in draft. 1

The spring group 83 is held normally com-l w pressed between front wall 88 of the yoke and follower bearing against stop lugs 81 o'n yoke arms 82, and draft spring group 84 under relatively higher compression between draft' stops 88 on the center sill I8 and follower 88 bearu 65 ing against rear wall 8l of the yoke and normally free of adjacent draft stops 98 on the center sill. 'I'he space 9| between draft stop 488 and adjacent follower 89 is designed to permit the building up of compression in front 70 spring group 83 and the rear spring group L16 to approximate that of draft spring group 84 andfor the reasons outlined above in connection with a similar arrangement for draft l spring group 66 of the other embodiment.

In draft operations the forward movement of coupler 30 will carry with it the yoke with front spring group 83 and associated follower! 85 case of the draft spring group of the other em bodiment, draft group l84 only will function in draft operations, and all of them will function to resist bufling shocks.

To insure working alinement of followers 85 and 86, their opposing faces are formed with circular flanges 93 and 84, respectively, functioning telescopically under draft movements, as shown in said figures, the flanges 94 of smaller diameter being relatively shorter than companion flange 93 of larger diameter to engage adjacent face of follower 8G to obtain the benefit of the relatively large area of that section in buffing.

For the purpose of i slidably supporting the front yoke and contained spring groups a plate 95 is removably secured to the underside by bolts 96, as best shown in Figs. 3, 4 and 9.

It will be noted that the spring ygroups in front of the bolster of the preferred form function in series on buff with respect to each other as though the spring units comprising them were in a single group, and both in parallel with the spring group 15 back of the bolster, to the tudinally between the center sills and upon op- 10,

posite sides vof said bolster, and an intermediate transmitting member slidably supported within and projecting normally rearwardly of the bolster for engagement with said rear springs,

and projections cn said member engageable with y15.

said bolster'for restraining forward movement thereof under thrust of the rear springs during draft operations.

2. 'I'he combination with a car underframe including a bolster and a pair of center sills, 20:

of a draft gear comprising springs spaced longitudinally between the center sills and upon opposite sides of said bolster, and an intermediate transmitting member slidably mounted within and projecting normally rearwardly of the bol- 25 ster, and restraining means on said member and bolster for preventing displacement of said transmitting member-under thrust of the rear springs during draft operations.

WILLIAM H. MUSSEY. MARTIN P. BLOMBERG.

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