US2813711A - Package spring group - Google Patents

Description

Nov. 19, 1957 Filed Aug. 26, 1954 R. B. COTTRELL 2,813,71 1

PACKAGE SPRING GROUP 2 Sheets-Sheot 1 INVENTOR.

Nov. 19, 1957 R. B. COTTRELL PACKAGE SPRING GROUP 2 Sheets-Sheet 2 Filed Aug. 26, 1954 PACKAGE SPRING GROUP Robert B. Cottrell, Deer-field, 111., assignor to American Steel Foundries, Chicago, 111., a corporation of New Jersey Application August 26, 1954, Serial No. 452,333

17 Claims. (Cl. 267-9) This invention relates to removable spring groups and more particularly to a friction snubbing device built therein for controlling the oscillation of the loading springs in railway car trucks.

Although railway car trucks now have snubbing or spring oscillation dampening devices integral therewith, it has become necessary to design a spring group package, or unit, complete with built-in snubbing devices that can be easily installed in older railway car trucks.

One general object of this invention is therefore to devise a package spring group with a builtin snubbing device.

Another general object of the invention is the provision of friction control means wherein the capacity of the load springs is supplemented by the friction springs.

A specific object of the invention is to devise a spring group, wherein the physical arrangement is such that the friction assembly will not interfere with the operation of the load spring.

Yet another specific object of the invention is the defining of a snubbing friction shoe that is easily accessible and replaceable.

These and other objects of the invention will become apparent from an examination of the following specification and the accompanying drawings, wherein:

Figure 1 is a fragmentary top half plan view of a spring group embodying the invention.

Figure 2 is a side elevatio-nal view of the structure shown in Figure 1 with the left half being shown in section taken along line 22 of Figure 1.

Figure 3 is an end elevational view of the structure shown in Figure 1 with the right half being shown in section taken along line 3-3 of Figure 2,

Figure 4 is a side elevational view similar to Figure 2 illustrating another embodiment of the invention, and

Figure 5 is a partial sectional view of the friction shoe taken along the plane indicated by line 5-5 of Figure 2.

Describing the invention in detail and referring first to the embodiment thereof illustrated by Figures 1 to 3, the spring group comprises a plurality of load coil springs 5 interposed between a top spring plate 6 and a bottom spring plate 8. Also included between the plates at each end thereof are friction assemblies 10, each comprising a friction shoe 12 angularly abutting the top plate 6 and supported from the bottom plate 8 by a friction shoe spring 14.

The bottom plate 8 is a relatively flat casting having end walls 16 and side walls 18 cast integrally therewith, all four walls defining a cavity for friction springs 14 and load springs 5. The end walls 16 additionally have friction surfaces 17 on the inboard sides thereof abutting friction surfaces 21) on the outboard sides of friction shoes 12. The bottom plate 8 additionally has lugs 22 and 24 disposed on the floor thereof to position friction springs 14 and load springs 5, respectively.

The top plate 6 is also a flat casting having vertical side walls 26 and vertical end walls 28. Extending outboardly from top plate at each end thereof are bifurcated 2,813,711 Patented Nov. 19,

flanges 30 approximately triangular in shape as seen in side elevational view, each having as sides the end walls 28, a downward curving extension 32 of top plate 6 and a friction side 34 angularly disposed therebetween and having on its under and outboard side a friction surface 36 abutting another friction surface 37 of the friction shoe 12.

Disposed on diagonally opposed corners of top plate 6 and bottom plate 8 are retaining lugs 38 and 40, their function being to anchor interconnecting retaining loops 42, which serve to secure the spring group in an assembled position.

The friction shoes 12 are one-piece castings, each comprising a cylindrical structure housing friction spring 14 and having a flat vertical outboard wall 13 on which is disposed friction surface 20, abutting and engaging a friction surface 17 of bottom plate 8. The shoes additionally comprising end wall 20 and arcuate inboard wall 19 and on either side thereof angular walls 21, which are approximately parallel to friction sides 34 of top plate 6 and have friction surfaces 37 engaging friction surfaces 36.

It will be apparent from an examination of Figure 4, wherein is illustrated another embodiment of the invention, that the friction shoe assembly is separated from the load springs by end wall 50 and the assembly is reversed from that of the previous embodiment so that its friction contact with the bottom plate is at the friction surface on the outboard side of the end Wall 50.

Describing the operation of the invention, it will be noted that the weight of the car carried by a bolster, which is supported by the spring group in the usual manner, known to those familiar to the art, exerts a downward vertical pressure on the top plate 6. This pressure of course is greatly increased when a bump is encountered. This pressure is transmitted through friction surface 36 of top plate flange 30 to friction shoe 12 through its friction surface 37, and at the same time friction spring 14 is exerting an upward pressure on friction shoe 12; thus because of the wedge shape of the friction shoe, the pressure from the top and the side combine to force its friction surface 20 against the vertical friction surface 17 of the bottom plate end wall 16, causing a snubbing or dampening the oscillation of the load springs to take place.

This snubbing process is the same, in the case of the embodiment illustrated by Figure 4, even though certain of the parts are in the mentioned reversed position.

To retain spring group in an assembled position for purposes of installation and shipping, a retaining loop 42 may be secured around retaining lugs 38 and 413 on the top plate 6 and bottom plate 8 while spring group is in an assembled condition.

I claim:

1. In a removable package spring group for railway car trucks, a base plate having transversely extending walls with friction surfaces on the inboard sides thereof, a plurality of coil load springs carried on the base plate centrally thereof, a cover plate supported by said load springs and having downwardly extending walls, flanges transversely extending and angularly related to the cover plate on the ends thereof and having friction surfaces on the outboard sides thereof, friction members disposed adjacent said springs, each of said friction members having wedge surfaces thereon engaging a related friction surface of said cover plate, said members having friction surfaces abutting the friction surfaces of said base plate, and springs supported by said base plate and carrying said friction members.

2. A spring group for railway car trucks, said group comprising top and bottom plates, each plate having Walls with friction surfaces thereon extending transversely of the group and disposed adjacent each other, a plurality of coil springs disposed within and centrally of the group, friction members disposed within said group at the ends thereof and outboardly of said coil springs, said members having friction surfaces abutting and engaging the friction surfaces of said plates, and springs interposed between said members and the bottom plate, the compressional axes of said last mentioned springs extending in the longitudinal vertical center plane of the group.

3. A spring group for a railway car truck according to claim 2, wherein the friction surfaces on the top plate converge toward the transverse vertical center plane of the group.

4. A spring group according to claim 3, wherein the friction surfaces on said top plate are spaced from each other transversely of the group, and other of said friction surfaces on the members engage the friction surfaces of said top plate, and the last mentioned springs are interposed between said spaced friction surfaces.

5. In a spring group, a top plate generally flat having end and side walls extending downwardly, the end walls having wedge shaped flanges with friction surfaces thereon, a bottom plate generally flat with end and side walls extending upwardly, the last mentioned end Walls having friction surfaces on the sides thereof, a plurality of springs disposed centrally of the group between said plates, friction means to engage the friction surfaces of said top and bottom plate, said means comprising friction shoes, each of said shoes having a partly cylindrical body portion and wing-like wedge flanges extending laterally therefrom approximately parallel to the flanges on the top plate, friction surfaces on the wing-like wedge flanges and on the body portion, and springs supported by the bottom plate, said springs carrying said shoes in order to engage the last mentioned friction surfaces with the related friction surfaces of the top and bottom plates.

6. In a readily removable spring group package for a railway car truck, an upper plate being generally flat and having longitudinally spaced end walls and transversely spaced side walls extending downwardly therefrom, said end walls extending transversely of the group and having wedge shaped flanges with friction surfaces thereon, a lower plate being generally flat and having longitudinally spaced end walls and transversely spaced side walls extending upwardly therefrom, said last mentioned end walls having friction surfaces on corresponding sides thereof, a plurality of load coil springs disposed centrally of the group intermediate said plate, friction means to engage the friction surfaces of said upper and lower plates, said friction means comprising friction shoes each having a substantially cylindrically shaped body portion, Wedge flanges extending laterally therefrom, said flanges being disposed in planes approximately parallel to the flanges on the upper plate, friction surfaces on said last mentioned flanges and said body portion, spring means disposed between the lower plate and friction shoes whereby said spring means forces said last mentioned surfaces into engagement with the related friction surfaces of the upper and lower plates.

7. In a readily removable spring group package for a railway car truck, a base plate, vertical friction walls on said base plate extending transversely of the plate and disposed on opposite ends thereof, atop plate vertically spaced from the base plate, a plurality of coil load springs supported by the base plate intermediate the ends thereof and supporting the top plate, said friction walls being disposed outwardly of the load springs on opposite sides thereof, wedge means on the top plate disposed on opposite ends thereof above and adjacent the respective friction Walls, each of said wedge means comprising wedge surfaces spaced from each other transversely of the plate, said Wedge surfaces converging on the transverse center plane of the group, friction shoes disposed at opposite ends of the group adjacent the friction walls and the wedge means, each shoe having a substantially cylindrieally shaped body portion disposed intermediate the related surfaces of the wedge means, and wing-like wedge walls extending laterally from opposite sides of the body portion, wedge surfaces on the wedge walls engageable with the wedge surfaces of the top plate, other friction surfaces on the body portions engageable with the friction Walls of the base plate, and resilient means compressed between each shoe and said base plate wherein said compressed resilient means forces said Wedge surfaces and said other friction surfaces to engage their related surfaces.

8. in a friction assembly for a snubbing spring group, an actuating spring, a friction shoe comprising spaced vertical walls and a horizontal wall with a spring seat thereon extending therebetween, one of said vertical walls being flat and having a friction surface on the outer side thereof, the other of said walls having a semi-cylindrical center portion and spaced flat end portions substantially parallel to said one wall, spaced wedge walls extending between said friction wall and the respective end portions of said other wall, and having wedge surfaces thereon, said friction and wedge surfaces being angularly related to each other and operative to engage certain abutting structure in the group in a wedge-like manner.

9. In a spring group, an arrangement comprising two vertically spaced substantially transversely extending flat plates, the upper plate having cast integral therewith vertical side Walls and wedge shaped end walls having friction surfaces thereon, the lower plate having vertical side Walls vertical and outer end walls, said lower plate also having an inner set of vertical walls intermediate the outer walls and having friction surfaces thereon, a pinrality of coil springs disposed between said plates intermediate the inner walls of the said lower plate, friction shoes disposed between said plates intermediate the respective inner and outer walls of the lower plate, said shoes having friction surfaces on the upper and inboard sides thereof engaging the associated surfaces of the respective plates, and springs supported by the lower plate forcing the friction shoes against related friction surfaces.

10. A spring group according to claim 9, wherein the friction surfaces on the wedge shaped end walls converge upwardly.

11. In a removable spring group for railway car trucks, a horizontal relatively flat cover plate having vertical side Walls and end walls angularly depending therefrom, said end walls having friction surfaces on the inboard sides thereof, a horizontal relatively flat base plate having vertical side walls and end walls, the end walls having friction surfaces on the outboard sides thereof, a plurality of springs mounted between said plates centrally thereof and disposed between the end walls of said base plate, a pair of snubbing devices, each having friction surfaces on the upper and inboard sides thereof engaging the friction surfaces of said plates, and spring means operatively engaging said devices in order to engage the friction surfaces of the snubbing devices with the friction surfaces of said plates.

12. In a spring group for a railway car truck, an arrangement comprising a cover plate relatively flat having vertical side and end walls and having extending beyond each end wall a wedge-like flange, said flanges having friction surfaces on the undersides thereof, and 'a base plate relatively flat having vertical side and end walls, said end walls having friction surfaces on the inboard sides thereof, a plurality of coil springs interposed between said plates centrally thereof, friction members interposed between said plates adjacent said springs and having friction surfaces on various sides thereof engageable with the friction surfaces of said plates, and springs supporting and offering pressure against said friction members.

13. In a spring group, a base plate, vertical friction walls on the base plate, said walls extending transversely of the group and disposed at opposite ends thereof, a

top plate vertically spaced from the base plate, a nest of coil springs supporting by the base plate centrally thereof, said springs supporting the top plate, said friction walls being disposed on opposite sides of said coil springs, wedge means on the top plate located on opposite ends thereof above and adjacent said friction walls, respectively, each of said wedge means comprising wedge surfaces spaced from each other transversely of the group, said wedge surfaces converging on the transverse vertical center plane of the group, and friction shoes at opposite ends of the group adjacent the friction Walls and the wedge means, each shoe having a central substantially cylindrical shaped body portion disposed intermediate the related wedge surfaces of the wedge means and wing-like wedge surfaces on opposite sides of the body portion engageable with the mentioned related wedge surfaces of the wedge means, each shoe having another friction surface engaging the related friction wall, and spring means compressed between one of the plates and each friction shoe.

14. A spring group according to claim 13, wherein the wedge surfaces on the wedge means converge downwardly on each other.

15. A spring group according to claim 13, wherein the wedge surfaces on the Wedge means converge upwardly on each other.

16. A spring group according to claim 13, wherein the spring means is compressed between the related shoes and the base plate.

17. A spring group according to claim 13, wherein the wedge surfaces on one plate are disposed on the outer surface thereof, and wherein the friction surfaces on the other plate are disposed on the inner surfaces thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,295,548 Cottrell Sept. 15, 1942 2,295,556 Flesch Sept. 15, 1942 2,483,184 Cottrell Sept. 27, 1949 2,527,356 Cottrell Oct. 24, 1950 2,657,040 Ramos Oct. 27, 1953

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