US1990379A - Spring suspension for railway cars - Google Patents

Description

Feb. 1935- c. J. HOLLAND 1,990,379

SPRING SUSPENSION FOR RAILWAY CARS Original Filed July 25, 1927 2 Sheets-Shet l 3mm k Feb. 5, 1935. I c. J. HOLLAND SPRING SUSPENSION FOR RAILWAY CARS Original Filed July 25, 1927 2 Sheets-Sheet 2 I gwue'nhw Civrzas ,zoZZ'ayd Patented Feb. 5, 1935 PATIENT OFFICE}? SPRING SUSPENSION FOR. RAILWAY cans Cyrus J. Holland, Chicago, Ill., assignor to Holland Company, Chicago, Ill., a corporation of Illinois Original application July 25,. 1927, Serial No. 208,349. Divided and this application August 20, 1934, Serial No. 740,700

8 Claims. '(Cl. 267-4) This application is a division of my co-pending application for patent for volute spring structure for railway trucks, filed July 25, 1927, Serial No. 208,349, and a substitution in part of my co- 5 pending application Serial No. 492,045, filed October 29, 1930, for Volute springs adapted for trucks.

The invention relates to cushioning devices or spring means for general use and adapted particularly for employment in railway trucks for resiliently supporting the load.

Until about ten years ago the provision of cushioning means in railway freight car trucks was a comparatively simple problem to solve, a common practice being to provide a suitable number of helical springs interposed between the spring plank and the bolster because the standard A. R. A. double coil freight car truck spring provided the necessary capacity for the various 20 classes of cars by varying the numberof coils used in accordance with the capacity of the car. Ordinarily the window openings in such trucks, both arch bar and cast steel truck side frame, limited the number of springs in the nest to five 2 double coils. About ten years ago, the American Railway Association changed the method of figuring the capacity of a car so that a 100,000 pound capacity car, which at that time was permitted to carry a 10% overload, became a car 30 that could carry a maximum of 169,000 pounds including the weight of the car. This change permitted cars to be loaded heavier under the new ruling than under the old, and developed the fact that the four double coil spring nest did not have suificient capacity to take care of the new load. 7 The A. R. A. have since that time endeavored to increase the capacity of their standard double coil truck spring from 16,000 pounds to 20,000 40 pounds per double coil. In an effort to do this they designed a chrome molybdenum double coil spring fully described in the Car Builders Encyclopedia of 1922 and subsequent issues. However, this spring appears not to have met the requirements because it has not gone into general use and as an alternative cars of 169,000 pounds capacity and over have generally been equipped with the Dalman or similar type of 50 truck in which a larger window opening is proin the spring nest.

It is with the above facts in view that I have designed the present invention which has for its general object the provision of truck springs of 5 such character as to have the necessary capacity vided which permits of using more than five coils without increasing the number in the group over the number of helical springs commonly used,

and without necessitating any change in the side frames, the size of the window openings or the wheel base.

An important object of the invention is to provide spring means of such high capacity type which maybe installed in already existing trucks without necessitating any changes or modificatlons therein.

More specifically stated, the invention resides in the employment of volute springs in railway trucks instead of one or more of the usual helical springs as I have discovered that springs of the first-mentioned form have a much greater capacity, size for size, than those of the latter mentioned type.

Another object of the invention is to provide a group of volute springs alone or in conjunction with helical springs and which may be initially assembled for subsequent installation within the window opening of a side frame, various alternative arrangements, in pointof relation, etc., being contemplated.

Another object of the invention is to provide a volute spring in which the relation of its capacity to its travel at any point in the latter may be constructed so as to insure the most emcient action at all varying loads, it being a feature that the spring may be formed from stock which vaportion .of the travel of the springs and a relatively faster rising ratio of load to deflection for the latter portion of the travel.

To the attainment of the foregoing and other objects and advantages; the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed,-

Fig. 2 is a section taken on the line 2--2 of Fig. 1;

Fig. 3 is a detail view partly in elevation and partly in section through one of the volute springs;

Fig. 4 is a side elevation of stock of varying width from which a spring may be formed in acthe numeral 1 designates a portion of a railway car truck including side frames 2, only' one of which is shown, each of which has a window opening 3 therein defined between column guides 4 at the bottom of which is a seat 5 supporting the spring plank 6. The numeral 7 designates the truck bolster which projects into the window ope-ning 3 and which is supported by my novel spring assembly-indicated as a whole by the numeral 8. It is, of course, well known that it is the customary practice to support the bolsterby compared therewith.

means of a nest or cluster of helical springs commonly confined between caps. In its broadest aspect, my invention contemplates the'employment of a corresponding nest or cluster of volute springs which may be held in place in substantially the same manner as the ordinary helical springs but which will have increased capacity as This cluster or assembly 8 is shown as comprising upper and lower caps 9 and 10 between which are arranged the volute springs 11 which are preferably constructed in the specific manner to be described and which may be arranged in the same relation as regards coiling or which may be arranged in reversed relation as disclosed in my -copending application above identified. Furthermore, in the case of a lateralmotion truck, the

' springs may be arranged with their small ends entering the small ends of the springs.

either at the top or at the bottom as set forth in my Patent No. 1,916,317. For holding the cluster assembled prior, to installation in the truck, the top and bottom caps are preferably connected by a tie bolt 12 having its head seated within a socket 13 in the upper cap and carrying a nut 14 seated within a similar socket 15 in the lower cap. The springs themselves may be held against displacement with respect to the caps as by providing flanges 16 on the caps engaging exteriorly of the large ends of the springs, and projections 17 stamped out of the caps or otherwise formed and These are mere mechanical details which may be readily varied without afiecting the general principles of the invention.

In accordance with the actual carrying out of the present invention, I contemplate using the springs 11 which'are peculiarly formed so as to possess certain desirable characteristics particularly as regards the relation between the capacity and travel, especially at different points in the latter so that the proper spring resistance under all varying loads will be obtained. I have found that the most desirable results can be brought about by providing more metal in the smaller convolutions than in the larger. This can be brought about readily in either one of two ways, namely by forming the spring of bar stock tapered in tion insures a better relation to the retaining flanges 16 on the caps.

The spring shown in Fig. 3 is made from a bar 18, illustrated in detail in Figs. 4 and 5, tapered in width and so coiled that the successive convolutions 19, 20, 21, 22 and 23 will be of progressively increasing width or height, the innermost active coil being the widest. The diagonally opposite corners are beveled off as at 24 so that the springwill stand square. Both ends of the bar are represented as tapered off .in thickness as at 25 and 26 so that the opening in the smallest convolution will be substantially concentric with the outermost convolution and so that both will be substantially circular.

Instead of using the bar stock shown in Figs. 4 and 5, I may form the spring from a bar such as that shown at 27 in Figs. 6 and '1, this bar being tapered in thickness from a point 28 near the end fonning the smallest convolution, the diagonally. opposite corners being beveled oif at 29 to provide bearing portions forming proper seats. less of whether the spring be formed from the stock illustrated in Figs. 4 and 5 or Figs. 6 and 7, the fact remains that the metal in the largest coil w.il have a smaller cross section than that in all of the other coils with the exception of the innermost. By properly proportioning the increment, the action of the spring, as regards its capacity or resistance to compression at any point in its travel may be determined and definitely fixed.

In the'operation, it is apparent that the springs will act to cushion the load in the same general manner as the well-known helical springs. However, I have found that increased spring capacity can be obtained in the same space by substituting volute springs for helical springs. The stiifness of the springs at diiferent points in the travel 30 Regard-.

thereof can be regulated by the tapering feature stressed, and it is therefore possible to construct the springs in such manner as to obtain what may be considered the ideal condition in service.

Above, I have described the employment of volute springs alone substituted for the usual and well-known helical springs. However, it should be understood that it is not necessary that I be restricted in this respect as I also contemplate making use of a combination of helical and volute springs, or in other words replacing one or more of the usual helical springs with the volute springs of the special construct ion above set forth. In Fig. 8 itwill be observed that the bolster 7 which extends within the window opening 3 of the side frame 1 is supported upon volute springs 11 and also upon helical springs 30 of conventional pattern. There is no restriction as to the relative number of volute and helical springs in each assembly. As shown in Fig. 8, one-half of the spring assembly comprises one volute and one helical. The other half duplicates this construction whereby the resistance to the downward movement of the bolster is substantially the same at opposite sides of the center line thereof. Other arrangements of these-springs may be made, if desired. Since these arrangements are obvious it is not thought necessary to further illustrate or describe the same. Moreover, it makes no difference whether the volute or the helical springs be located closer to the end of the bolster. All such variations come within the purview of the invention.

Regardless of whether the volute springs are used alone or in combination-with the helical springs, it is quite clear from the foregoing description that there will be a slowly rising ratio of load to deflection for the first portion of the travel of the spring nest and a relatively faster rising ratio of load to deflection for the latter portion of the travel. This is one of the primary objects sought for and by the construction and arrangement set forth it is apparent .that it has been achieved. The above characteristics may be varied, as desired by varying the cross-sectional area of the different portions of their volutes.

In order to secure the desired capacity and at the same time have sumcient travel for use in railway trucks, the volute springs are preferably made with few turns oicognparatively wide stock.

It is a dimcult problemto properly resiliently support railway freight carsfrom the car trucks.

If the springs are too stifi, there" will not be sum-' cient resiliency for the cars when empty or lightly loaded, and if they are not stiff enough, they are likely to go solid when the car is travelling at load capacity, often causing distortion or breakage of the side frames of the supporting trucks.

Helical springs are well adapted for resiliently supporting railway cars except that they require some means for preventing harmonic vibration as otherwise they are too likely to go solid under maximum load during these vibrations. By combining them with mcdified volute springs, the ideal condition of spring suspension may be approximated during compression; the turns of the volute frictionally engage each other, thereby dampening harmonic action of the whole assembly. Furthermore,when the turns of the volute begin to settle, the volute becomes much stiffer and its capacity is markedly increased during further compression, whereby the volute will not only dampen the periodic vibration of the springs,

but will also ofier an extremely great resistance to the springs going solid.

,Helical springs for use on freight cars are designed to carry a maximum load at only one-half of their maximum deflection in order that they may not go solid under abnormal conditions, as .when harmonic action occurs in the assembly. By the use of volutes with the helical springs to prevent this harmonic action, the maximum load may be increased without danger of the springs going solid under abnormal conditions. Now, if the turns of the volute in this assembly be tapered so that the largest cross section is in the smallest turn, the load deflection curve of the entire volute helical spring assembly will be a curve from .the start. As a result of tapering the turns of the volute, the assembly will support light loads with the desired resiliency as well as support heavy loads with the proper resiliency. The cross sectional area of the turns of the volute may be varied to obtain any characteristic load deflection curve that may be desired. Owing to the high resistance to compression its final movement, only one or two volutes of the conventinal dimensions for helicals are necessary in a spring assembly.

In the employment of volutes formed from tapered stock along with helicals in a spring assembly, the volutes will not only prevent harmonic action of the entire assembly-but will also cushion the finalmovement of the bolster-with such great resistance as to prevent the springs going solid and will also provide an assembly which will .carry a light load, as well as a heavy one with the desired resiliency.

While I have shown and described the preferred embodiment of the invention, it should be understood that the disclosure is merely an exempliflcation of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of 1 utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or the scope of assembly also comprising a helical spring formedof stock of substantially uniform cross section, all of the springs of said assembly operating in parallel when theassembly is compressed.

2. In a railway car, a truck provided with a frame having a spring seat thereon,abolster above said seat, 'a spring assembly for supporting said bolster from said seat, all parts of said assembly beingbeneath the plane of said bolster, said assembly comprising volute spring means and helical spring means, said volute spring means having its intermediate turns of different widths, said turns frictionally engaging one another for dampening the periodic vibration of said assembly during the movement of. said truck, the springs of said assembly acting in parallel for resisting the downward movement of said bolster.

3. In a railway car, a truck, a bolster, a spring assembly for supporting said bolster from said truck, said assembly comprising volute spring means and helical spring means, said volute spring means having its intermediate portion formed from tapered stoclr, said portion tapering, outwardly from the innermost coil and provided with rubbing surfaces for dampeningthe periodic ,vibraticns of said spring assembly during the movement of said truck, all parts of said assembly being located beneath the plane of said bolster, said springs operating in parallel when said assembly is compressed.

4. In a railway car, a truck, a spring assembly for supporting a load from said truck, said assembly comprising a plurality of coil springs at least one of said springs having between its ends, flexing turns of varying cross-sectional area, turns of said one spring being provided with rubbing surfaces for dampening the periodic vibrations of said assembly during the travel of said truck, follower members extending across theends of the springs of said assembly and movable toward each other for causing the compression of said springs in parallel when said assembly is compressed, all parts of said spring assembly being located between the planes of said members. 1

5. In a railway car, a truck provided with a frame having a bolster opening therein, a bolster having one end extending into said opening, a-

prising at least one helical spring and one volute spring, certain of the intermediateturns of said volute spring varying in cross-sectional area, and

frictionally engaging one another for dampening the periodic vibrations of said assembly during the travel ofsaid truck, said springs operating in parallel.

6. In a railway car, a truck having a side frame provided with a bolster opening, a bolster having one end portion extending into said opening, said frame being provided with a spring seat, a spring assembly insertable in said opening between the planes of said seat and bolster for supporting said bolster from said frame, said assembly comprising a plurality of coil springs operating in parallel, at least one of said springs being formed by a comparatively few turns of relatively wide tapered stock rectangular in cross section, the intermediate portion of said spring being provided with curved rubbing surfaces for frictionally resisting the harmonic action of said assembly during the travel of said truck.

'7. In a railway car, a truck side frame having a window opening and a spring seating portion therebeneath, a bolster having spring seating portions on its under side and an end portion in said window opening, a spring assembly for supporting said bolster from said truck frame, said assembly consisting of a plurality of springs having overlapping coils, certain of said coils varyingin cross sectional area and being substantially rectangular in cross section and having surfaces adapted for a rubbing action relative to one an-' other for resisting harmonic action of said spring assembly, and means at the ends of said springsincluding inwardly disposed flanged portions C011,

tacting outside portions of said springs for locating said springs in their relative positions in the assembly, said means movable toward each other for causing the compression of all of said springs.

8. In a railway car, a truck having a side frame provided with a bolster opening, a bolster having ing coil springs, all springs of said assembly op-.

erating in parallel and having their intermediate turns rectangular in cross section and provided with curved rubbing surfaces for resisting harmonic action of said assembly during the travel of said truck, said springs operating in parallel, and means for positioning said springs beneath said bolster.

' CYRUS J. HOLLAND.

Images