US2199907A - Springing for railway trucks - Google Patents

Description

y 7, 1940- c. D. BARRETT ET AL 2.199.907

SPRINGING FOR RAILWAY TRUCKS 4 Sheets-Sheet 1 Filed Feb. 15. 1939 -INV ENTOR5: Charles D. Barrett 8:.

I NESSES:

flharles RJ llhiig ATTORNEYS.

' May 7, 1940. c. D. BARRETT ET AL SPRINGING FOR RAILWAY TRUCKS Filed Feb. 15', 1939 4 SheeiZs-Sheet -2 ,llllllll/llllll INVENTOR5:

Charles D. Barmii &.

WITNESSES:

Charla;

May 7, 1940 c. o. BARRETT :1- L SPRINGING FORVRAILWAY 'I RUCKS Filed Feb. 15, 1-959 4 Sheets-Sheet s Q :QQNQQ INVHN'IHRS: Charles ll barl'efi (Ya Charles ILWiLiiehead,

May 7, 1 0- c. DQBARRETT- El AL SPRINGING FOR RAILWAY TRUCKS Filed Feb. 15, 1939 Sheets- Sheet 4 all!!! x M 2 1W, WW

Patented May 7, 1940 SPRINGING FOR RAILWAY TRUCKS Charles D. Barrett and Charles R. Whitehead,

- Altoona, Pa.

Application February 15, 1939, Serial No. 256,463

13 Claims.

This invention relates to springing for railway trucks and the like, and is especially advantageous in increasing the space available for springs in bolster trucks, without necessity for corresponding increase in size or bulk of the truck and its parts. This permits a spring installation of greater load-carrying capacity than heretofore;

or, if preferred, an installation in which greater spring deflection is allowed, or in which the maximum intensity of stress in the springs is lower. Through the invention, the advantages of a nonharmonic or damped spring group can be secured in a freight truck,--including great reduction of shocks due to rail joints and other track irregularities, and generally improved riding qualities.

The invention can be applied to freight-car trucks of standard A. A. R. type, and can be installed on existing trucks by merely changing the springing itself,-or possibly also the bolster. It readily affords the further advantage of sheltering or enclosing springs that might be rusted by weather or car drip, and thus rendered ineffec tive.

American freight cars heretofore in common use have been equipped with very stiff springs of helical coil type: e. g., the springs of the standard A. A. R. 50-ton car deflect only inch when a capacity load is loaded into the car. Such stiffness and small deflection are due to the necessity of using comparatively small springs, that can be accommodated in the limited space afforded by a compact, inexpensive truck. With the increase in freight-train speeds in recent years, the shocks due to rail joints and other track irregularities are individually more severe, and the intervals between successive shocks tend to harmonize fairly closely with the natural periods of vibration of undamped helical freight-car springs, so that the spring vibrations build up periodically until the springs actually go solid from time to time,resu1ting in far worse shocks to car and lading than are produced by a single rough place in poor track. This may happen to a lightly loaded car, as well as to a car heavily loaded, and especially with very stiff springs, which have but little flexibility under light load.

In a freight-car truck, the high maximum loadcarrying capacity of stiff springs is desirable, to prevent the springs from going solid under severe shock; low maximum intensity of stress in the springs is desirable, to increase their life; and soft springs, with relatively large deflection in proportion to load, give easy r d q Taken alone, these considerations would point to larger and softer springs than heretofore used,

with larger and more expensive trucks. However, it is known that smoother, easier riding can be obtained without increasing the flexibility or softness of springs, by providing in the spring group suflicient friction to damp its action and 5 prevent the harmonic building up of spring vibration as above described. One preferred way of doing this is by a combination of coil and multileaf springs, preferably of elliptic type (e, g., elliptic or semi-elliptic); for while coil springs 10 give more capacity and do more work in proportion to their weight and the space they occupy, multileaf springsabs'orb in friction part of the work done in stressing them, instead-of returning all this werk on their recoll,thus damping out vibrations that would otherwise build up. Practically, the problem to install a damped spring group on a freight -car truck without ob- ,jectionably reducing the maximum spring'capacity or increasing the bull: of the springs, and the room required for them At the same time, it is desired to keep the maximum intensity of str -is in the springs low, and to allow considerable spring deflection under load If cost and weight did not have to be considered, and if the space available for springs were not limited by existing car bodies and clearances along rights of Way, it would be easy to devise many spring arrangements for freight cars which would give perfectly satisfactory riding qualities: indeed, trucks with springing similar to that of J passenger cars could. equally Well be used for freight cars, if this did not entail prohibitive increase in truck size, weight, or cost. As regards existing trucks, the problem is complicated by the fact that almost all freight cars now in use (though owned by many different railroads) are equipped with trucks having interchangeable cast steel side-frames and bolsters, of a standard A. A. R. design, and that a majority of these cast 40 steel side frames (installed within recent years) will be serviceable for many years to come; so

sign of side frame is impracticable for existing that any spring arrangement requiring anew de l trucks. Even for new trucks, also, there are strong reasons for preferring to install the A. A. R. truck and side frame, rather than any new design: 1. e., the effective strength and endurance of a truck design against the oft-repeated stresses which ultimately tend to destroy the frame cannot be determined by calculation, but only by the test of many years of actual service; and years of such experience with the A. A. R. design have proved it to be exceptionally satis factory as compared with other designs with I which railroads have had like experience.

In the effort to provide a non-harmonic spring arrangement that would be'practicable and satisfactory for freight cars, various expedients have been resorted to. Some of these have consisted in changes of the spring group under the bolster of the present standard A. A. R. truck; while others have surrendered the advantages of reinterchangeable with the side frames and bolsters of A. A. R. trucks. Certain designs of both kinds have been used to a substantial though minor extent; but they have all been subject to drawbacks, which account for theirnot finding general acceptance. I

The present invention allows of using a nonharmonic spring group in a standard A. A. R. truck, or in almost any ordinary bolster truck, without any of the drawbacks of previous freightcar trucks with non-harmonic spring groups, by a novel combination of spring means on the side frame of the truck and leaf-spring means (preferably of frictional, multileaf, elliptic type) extending lengthwise in the bolster, and acting in parallel with the first-mentioned spring means to aiford the bolster resiliently yielding support. Not only can standard A. A. R. side frames be used, but standard A. A. R. bolsters can be converted for use in our truck,or it can be built with specially modified bolsters interchangeable with standard A. A. R. bolsters. On occasion, the special combination of springs can be replaced with a standard A. A. R. helical spring group,as when replacements for broken parts of the special springing are not available. A spring plank is not necessary, though it can be used with our truck, if .desired.

.Instead of having reduced spring capacity as. compared with the standard A. A. R. truck, our truck may have greater spring capacity than any known truck using the A. A. R. standard side-' frame, or any other side-frame in general use. This is because the whole window opening of each side frame under the bolstercan be fully available for coil springs, as in standard practice; so that the leaf spring means inside the bolster represents a clear gain in spring capacity. Or, if preferred, the maximum load capacity of the springs in our truck may be the same. as heretofore, and the deflection in relation to load may be greater, or the intensity of stress in the springs lower, or both. The enclosure of leaf springs in the bolster not only prevents a broken leaf sprin from falling to the road-bed and causing a derailment, but allows of protecting the leaves of a multileaf spring from being rusted together by weather moisture or by drip from the car (especially in the case of a refrigerator car with brine tanks), 50 as to render the spring virtually rigid and ineffective. The force of the leaf spring means can be applied on the fore and aft center lines of the coil spring means and of the truck side-frame, so that there shall be no lateral shift of the resultant spring forces, and no special lateral thrust on the guiding surfaces for up anddown movement of the bolster relative to the side frame. And there is no dimculty in shimming up the bolster when wheels slightly smaller than standard are used, in order to maintain the proper elevation of car couplers above the track,

Various other features and advantages of the in accordance with our invention; Fig. II shows a partial longitudinal section through the bolster and the associated spring plank and coil springs, taken as indicated by the line and arrows II--II in Fig. III, the leaf spring and its supporting columns appearing in side elevation, and the truck side frame appearing in cross-section; and Fig.

. III shows a horizontal section through the bolster, taken substantially just below its top wall. I

Fig. IV is a sectional view similar to Fig. II, showing a leaf spring in the bolster with arms of unequal length. L

Fig. V is a view similar to Fig. Iillustrating a modified construction, the bolster, the spring plank, and associated parts appearing in vertical section substantially in the longitudinal central plane of the side frame; and Fig. VI is a corresponding fragmentary sectional view at right angles to Fig. V, taken as indicated by the line and arrows VI-VI in Fig. 'V,

Figs. VII, VIII and IX are views similar to Figs. I, II, and III, illustrating still another modification.

Figs. X and XI are views similar to Figs. II and III, illustrating yet another modification; and Figs. 1G1. and XIII show cross-sections through the bolster, taken as indicated by the lines and arrows XIIX1I and X[IIXIII in Fig.'X, but with all other parts omitted.

In Figs. I, II, and III, there is shown a cast steel truck frame l0 including the upper compression member H, the lower tension member 52, and struts [3, I3 interconnecting these members of either side of the bolster window, and providing guideways for the end, of the hollow bolster l5, which has guide shoulders 16 to engage said guidew'ays. There is also shown a spring plank ll (of channel section) resting on the bottom l2 of the bolster window of the side frame Hi, and connecting this side frame to the opposite side frame, not shown. In the' bolster window under the hollow bolster end is a group of four helical coil spring I 8, preferably with smaller helical springs l9 loose inside them, and oppositely coiled. As shown, there are four of the springs It (with internal springs I9) form- .ing two transverse rows in parallel vertical transverse planes, as well as two fore and aft rows in' parallel vertical fore and aft planes equidistant at opposite sides of the central vertical plane,

- of the side frame ill,though of course the numbet and arrangement of the springs may be varied as desired. As shown, the springs l8, l9 are arranged substantially symmetrically with respect to the longitudinal central plane of the bolster, in theopposite side of the bolster window. Each spring I9 is engaged around outstanding circular fianges on upper and lower spring plates 20, 2|. The plate 20 may rest on the spring plank I! at the bottom of the bolster window, while the plate 2! may engage against the underside of the bolster end: and the plates may be interlocked with these parts by the usual projection and socketengagement means. As thus far described, the truck corresponds essentially to a standard A. A. R. side frame and bolster construction.

Inside the hollow bolster I5 are leaf spring means 22, shown as multileaf semi-elliptic springs, acting in parallel with the helical springs l8 and I! under the bolster end. In the present instance, there are two such multileaf springs 22, arranged alongside one another at opposite sides of a longitudinal vertical web 23 in the outer end of the bolster I5, and extending substantially lengthwise of the bolster. This web 23 interconnects the upper and lower walls of the bolster, and thus strengthens it; and. said web also forms separate compartments for the springs 22, 22, to keep them in position. The springs 22 22 may be attached to the bolster l5 by their inner portions,-preferably in such a way as to permit these portions to bend,-'while their outerends are 7 j free in the bolster. As here shown, the springs 22, 22 bear upward against an intermediate bearing seat 24 on the upper wall of the bolster, about under its side bearing 25 and at mid-length of the springs, and they bear downward at their inner ends against a lower inner bearing 26 on the bolster. Each upper seat 24 may have a concave cylindrical bottom surface conforming to a cylindrical surface on the spring strap 21, and the lower bearing 26 may have a convex cylindrical upper surface to which the bent ends of the (lower) spring leaves conform,the axes of these cylindrical surfaces extending fore and aft of the truck. The bearing 26 is shown as comprising a separate semi-cylindrical surfaced member removably mounted in a seat 28 extending across the interior of the bolster as a connection between its side walls, and forming part of the bolster casting. This seat 23 may also .be intermediately supported by pedestals 29 upstanding from internal longitudinal ribs on the bottom of the bolster, integral with the bolster casting. Aside from special features pertaining to the mounting of the spring means 22, the bolster l5 may correspond to the usual A, A. R. design. i As here shown, the central vertical longitudinal plane of each spring 22 coincides substantially with the common vertical axial plane of a corre-.

sponding pair of the nested coil springs, l8 and I9, though this is not essential. The outer end i of each spring 22 bears downward against a supporting member or saddle 30 inside-the outer hollow bolster end, between the upstanding side flanges 3| of this saddle. The bent outer ends of each spring 22 engage and conform to a fore 5 and aft cylindrical-surfaced bearing ridge 32 on the saddle 30, whose axis lies in the fore and aft vertical central plane of the whole group of'springs l8, l9, and of the side frame in. The bearing members or saddles 30 are supported from the side frame l0 independently of the coil springs l8, l9, and preferably from the side frame member l2 at the bottom of the bolster window; As shown, the supporting members or I saddles30 rest on upright struts or columns 33 1 whose lower ends bear or rest against said member I2,--or, more properly, on the spring plank ll,'-and whose upper ends extend loosely through openings in the lower wall of the bolster l and in the upper spring plate 2|, and engage in shalb low sockets, in the lower sides of the saddles 30. Accordingly, the members 30 cap and bridge the pairs of columns 33 on which they rest. Thus the outer ends 'of the several springs 22 are independently supported by different struts or columns 33. The openings in the lower wall of the hollow bolster I! may afford sumcient clearance around the struts 33 to permit some movement of the members 30 transversely of the truck, as required by the slight bending of the spring 22 as the bolster l5 moves up and down. Thus the outer ends of the springs 22 do not rub across the cylindrical bearing surfaces 32 of the saddles 30, and wear at this point is minimized. As the coil springs l8, l3 are in parallel with the leaf springs 22 (rather than in series) and act directly against the bottom of the bolster l5, and as these springs I8; l9 are quite stiff transversely of their own axes, they tend to stabilize the. bolster transversely of the truck, thus reducing or minimizing the pressure and wear on the bolster guiding surfaces at l6 and I3. In Figs, 11 and III, the struts or columns 33 extend axially through the convolutions of the coil springs l8 and I9.

It will be seen from Figs. I, II, and III that the leaf spring 22 is entirely enclosed in the bolster l5, so that it cannot fall out, even if broken. It is also well sheltered from weather and from car drip, which might otherwise reach the spring and rust its leaves together. This protection from moisture can readily be made complete by suitably closing up or covering the various openings 34 shown in the bolster walls, including even that at its outer end. As shown in Figs. II and III, the bearing member 30 and the bearing seat 26 may have upstanding ridges or lips 35 and 36 high enough to prevent endwise relative displacement of the parts 30, 26 and the spring 22, but not high enough to interfere with installation of the spring as hereinafter described. The bearing part 30 being connected to the. outer end of the spring 22 and to the upper ends of the columns 33 as against relative displacement horizontally (by virtue of the socketed inter-engagement of the part 30 with the parts 22 and 33 as above described), and the spring 22 bein fixed longitudinally in the bolster [5 (by its engagement at 24), it follows that the spring 22 controls the positions of the columns 33 relative to the apertured lower bolster wall through which they extend.' The socketed engagement of the columns at the bottom of the side-frame bolster-window (inside the circular flanges of the spring plank or the like, as variously shown in Figs. II, IV, V, VII, and X) contributes to the effectiveness of this control of the columns by the leaf-spring. When truck wheels somewhat smaller than standard are to be used, it is an easy matter to insert shims under the lower spring plate 20 and the lower ends of the columns 33,,so as to maintain the proper height of couplers above the track. The matter of suflicient clearancebetween the bolster and the top I I of the side frame In to allow of thus shimming up the bolster oifers no difficulty.

In assembling the truck, one method is to put each spring 22 in place through the open outer end of the bolster I5, with its inner end engaging the bearing 26 as the latter rests in its seat 28; then insert a lever (such as a crowbar) into the open outer bolster end, engage it under the free end of sprin 22 and flex the spring upward in the bolster sufficiently; and then place a block (introduced through the opening 34 in the lower wall of the bolster) between the free end of the flexed spring 22 and the lower horizontal bolster wall, just inside of the holes in said wall that take the inner column 33, and withdraw the lever or crowbar. -These operations having been carrid out for both springs 22, and I the open outer end of the bolster l5 having been inserted in the window in the side frame ID, the supporting means including the saddles 30, the columns 33, the springs I8, I 9, and the associated parts may be put in place under the blocked-up free end of the springs 22 and under the bolster; and then, finally, the blocks may be removed, as by knocking them inward from under the springs 22, allowing these springs to bear on the supporting means as shown in Fig. II

Alternatively, the springs 22 and the saddles 30 may be put in place in the bolster IS in the absence of the lower inner bearing 26; the bolster l5 may be inserted inthe window of the side frame ID; the springs' l8, l9 and the associated parts may then be put in place as above described; and finally the bearing 28 may be put in place under the inner end of the spring 22, by v 1 taking advantage of the'opening 34 in the lower bolster wall.

'The construction shown in Fig, IV differs from that of Figs. I, II, and III in that the arms of the leaf spring 22a at opposite sides of its upper bearing 24 are of unequal length, the outer arm Whose end rests on the bearing member being approximately twice as long asthe inner arm whose end rests on the bearing member 26. In other respects, the construction here illustrated is essentially 'the same as in Fig. II.

The constructionillustrated in Figs. V and VI difieres from that of Figs. I, II, III, and IV in that the supporting struts or colunms 33b for the bearing members 30b are not placed inside the rows of three. The spring 22b may either have Figs. II and III.

equal .arms, as shown in Figs. II and III, or unequal arms as shown in Fig. IV. The columns 33b are directly under the outer ends of the leaf springs 22, between the coils springs l8b of the pairs in the opposite side of the bolster window.

The construction illustrated in Figs. VII, VIII, and IX differs from that of Figs. I, II, and HI mainly as regards the provisions for supporting the leaf spring saddles 300 from the lower frame member l2forming the bottom of the spring window. As here shown, this is not done by means of rigid struts-or columns as in Figs. 1, II, and VI, but through elastically yielding inner columns, comprising helical springs I90 and short abutment or head members 38 whose shouldered lower ends engage the spring convolutions and whose reduced upper ends extend up through the openings in the bottom wall of the hollow bolster endl Thus the outer springs l8 act in parallel with the leaf springs 22, while the inner helical springs l9c act in series with theseleaf springs. somewhat different, consisting merely of end sockets 39 on the bolster side walls and of the upstanding pedestals 290. The part 360 connects the pedestals 29c to one another and to the side walls, and provides a ridge or lip like that in favorable for giving more deflection and easier.

'served from Fig. XI that their straps 21 have The seat for the bearing 26' is also riding, though with a lower total spring capacity. Thus it is suitable for high speed trucks to be used under freight cars in express service, in cases where the maximum car load capacity is .less than the axle capacity. The arrangements of Figs. I-VI, on the other hand, are more suitable for ordinary freight trucks to be used under cars which may be loaded to the maximum capacity of the axles, since these arrangements are more favorable for maximum load-carrying ca-. pacity of the springs.

Nothing has so far been said as to the condition of loading corresponding ,to the positions of the parts illustrated in Figs. I-IX. While the positions shown may correspond to total absence 1 of load on the bolster, this is not necessarily the case: on the contrary, it may sometimes be preferable to proportion the parts so that the bolster I5 will not, when substantially unloaded, bear on the coil springs that act in parallel with 2 the leaf springs 22, but will only come to bear on them (as shown in Figs. I, H, and IV-VIII)v after the bolster is sufl'lciently loaded to stress and deflect the leaf springs somewhat. Such pre-stressing of the leaf springs 22 ahead of the 2 parallel-acting coil springs is applicable to any of the arrangements illustrated in Figs. I-IX, or to other arrangements embodying our invention.

Fig. X shows an arrangement similar to that 3 in Figs. I-III with the parts proportioned to prestress the leaf spring 22, and in their positions without substantial load on the bolster l5. Accordingly, there is agap X between the 'underside of the bolster l5 and the spring plate 2|, 3

which in practice may amount to in., say. With a leaf spring 22 of suitable design, such a gap X would just close under a comparatively light load on the bolster,-a load less, perhaps,

than the weight of an empty car.

The advantages of thus pre-stressing the leaf springs 22 are most felt when the car is traveling lightly loaded or empty; i. e., under such lightrunning conditions,,the leaf springs 22, which naturally have less capacity than the helical 4| in parallel with these leaf springs (as shown in u Figs. VII-IX, for example), the pre-stressing of the leaf springs ahead of the parallel-acting coil springs involves concurrently.pre-stressing the serially-acting coil springs.

Fig. X not only shows some of the parts in positions different fromFigs. I and II, but also illustrates certain differences in construction.

As regards the leaf springs 22d, it will-be oba working fit between the sides of the spring compartments of the bolster lid, which are thickened to afford bearing pads 40, 40 (Figs.

XIand XII) for engaging the straps. The upperintermediate spring bearing seat 24 on the top,

bolsterwall is shown provided with a separate removable wear plate or liner 4|, preferably of hard metal. Not only are the free outer ends of the springs 22d engaged between the side. flanges 3| of the saddle member 30d, but the inner ends of said springs are loosely engaged between the shoulders of depressions 42 in the 7 lower inner bearing 2Gd,see Fig. XIII. Thus the springs 22d are definitely guided and held in line. As shown in Figs. X, XI, and XIII, the bearing 26d is not a separate removably mounted member, but is an integralpart of the bolster casting, spanned between its side walls and integral with the supporting pedestals 29: in other words, it represents a merger of the bearing 26 and seat 28 of Figs. II and III.-

Instead of receiving the upper ends of the columns or struts 33:1 in shallow socket depressions, as in Fig. II, the saddle members 30d receive the reduced upper ends 43 of the columns 33d in corresponding socket holes, and reston the shoulders around said reduced ends. The lower ends 45 of the columns 33d that rest or bear on the side frame member 12 (or rather on the spring plank ll) are preferably rounded to allow them to rock the more easily with any movement of the saddle 30 transversely of the truck; and as shown in Fig. X, they are spherical 1y rounded. For clearness of illustration, this roundingat 45 is considerably exaggerated in.

Fig. X: in practice, the radius of the surface 45 may be as much as the overall length of the columns, or even longer.

In Figs. IV to XIII, various parts and features are marked with the same reference numerals as in Figs. I to III, as means of dispensing with repetitive description ,letters being added to the numerals in instances where such distinction appears desirable.

Having thus described our invention, we claim:

1. In a truck, the combination with a side frame'having a bolster window, a hollow bolster with an end in said window, and spring means in said window under the bolster end yieldingly supporting the latter from said side frame; of

leaf spring means mounted inside the bolster wherein said supporting means comprises 001- I umns supporting the free end of the leaf spring means at their own upper ends, and at their lower ends bearing against the bottom of the bolster window and rounded to permit them to rock transversely of the truck with transverse movement of the leaf spring means which they support.

3. The combination as set forth in claim 1 wherein said leaf spring means comprises a multileaf spring bearing upward at an intermediate 5. The combination as set forth in .claim 1 wherein said supporting means comprises columns bearing against the bottom of the bolster window at different positions transversely of the trucli, with a bearing member capping and bridging said, columns and engaging the outer end of said leaf spring means substantially in the fore and aft vertical central, plane ofsaid side frame. I, 6. The combination as set forth in claim 1 wherein the hollow bolster end has an apertured lower wall resting on the spring means in the bolster window; and the supporting means for the outer end of the leaf spring means comprises column means bearing against the bottom of the bolster window and extending with clearance therearound up through said apertured lower wall of the hollow bolster end, and a bearing member in the hollow bolster end supported by the upper end of said column means and connected to'the same and to the outer free end of said leaf spring means against relative displacement of the parts horizontally, so that the leaf spring means controls the position of the column means transversely of the truek relative to said apertured lower bolster wall.

. 7. The combination as set forth in claim '1 wherein the hollow bolster end has an apertured lower wall resting on the spring means in the bolster window; and said supporting means for the outenend of the leaf spring means comprises column means in socketed engagement with the bottom of the bolster window and extending with clearance therearound up through said apertured lower wall of the hollow bolster end, and a hearing member in the hollow bolster end supported by said column means and in socketed engagement therewith and with the outer free end of said leaf spring means, so that the leaf spring means controls the position of the column means transversely of the truck relative to said apertured lower bolster wall.

8. The combination as set forth in claim 1 comprising coilspring means in the bolster window under the bolster end, for yieldingly supporting the same; and for supporting the outer end of the leaf spring means comprising inner coil spring means bearing against the bottom of the bolster window and extending up through the convolutions of said coil spring means, and acting in series with said leaf spring means.

' 9. In a truck, the combination with a side frame having a bolster window, a hollow bolster with an end in said window, and coil spring means in said window under the bolster end yieldingly supporting the latter from said side frame; of leaf spring means mounted inside the bolster lengthwise thereof, to flex up and down therein, with its outer end in the side frame window and free within the hollow bolster end; and column means under said outer end of said leaf spring means supporting the latter from the side frame I member at the bottom of said window, independently of said coil spring means; whereby said coil spring means and said leaf-spring means support the bolster in parallel with one another.

10. The combination as set forth in claim 1 wherein said supporting spring means under the bolster end comprises coil springs arranged substantially symmetrically with respect to the iongitudinal central plane of the bolster; said leaf spring means in the bolster comprises a plurality of multileaf springs bearing upward at intermediate points on intermediate bearings in the bolster, and at their inner ends bearing downward against the bolster; and there are separate columns independently supporting the outer ends of said multileaf springs.

11. The combination as set forth in claim 1 wherein said supporting spring means under the bolster end comprises pairs of coil springs in 0pposite sides of the bolster window; said leaf spring means comprises multileaf springs in opposite sides of the hollow bolster end; and there is a supporting column directly under the outer end of each multileaf spring, between the coil springs of the corresponding pair aforesaid.

12. The combination as set forth in claim 1 wherein the hollow bolster end has an apertured lower wall resting on the spring means in the bolster window; the leaf spring means inside. the,

bolster extending lengthwise thereof bears upward intermediate its ends on an intermediate upper bearing in the bolster; the supporting means for the outer end of said leaf spring means comprises column means bearing against the bottom of the bolster window and extending with clearance therearound up through said apertured lower wall of the hollow bolster end, and a bearing member in the hollow bolster end interposed between the upper end of said column means and the outer end of said leaf spring means, and in socketed engagement with both of them; and the bolster is provided with lower inner bearing means removably mounted thereon under the inner end of said leaf spring means.

13. In a truck, the combination with aside frame having a bolster window, ahollow bolster with an end in said window, and coil spring means in said window yieldingly supporting the bolster end for movement up and down in the window; of leaf spring means mounted in the bolster and extending lengthwise thereof and bearing upward intermediate its ends on an intermediate-upper bearing in the bolster, while its outer end is free in the hollow bolster end for yieldingly supporting the bolster in parallel with said coil spring means; supporting means for supporting the outer end of said leaf spring means from said'side' frame in the fore and aft vertical central plane of said coil spring means, but independentlyv of the latter; and lower inner bearing means on the bolster under the inner end of said leaf spring means.

CHARLES D. BARRETT.

CHARLES R. WHITEHEAD. 25

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