US2758549A

US2758549A - Railway truck with air springs

Info

Publication number: US2758549A
Application number: US472610A
Authority: US
Inventors: Richard L Lich
Original assignee: General Steel Castings Corp
Current assignee: General Steel Castings Corp
Priority date: 1954-12-02
Filing date: 1954-12-02
Publication date: 1956-08-14
Anticipated expiration: 1973-08-14

Description

Aug. 14, 1956 R. LICH 2,753,549

RAILWAY TRUCK WITH AIR SPRINGS Filed Dec. 2, 1954 2 Sheets-Sheet 1 INVENTOR. e/c/mea 1. L/CH Aug. 14, 1956 R. L. |c|-| RAILWAY TRUCK WITH AIR SPRINGS 2 Sheets-Sheet 2 Filed Dec. 2, 1954 INVENTOR. E/CHAED L. L/CH United States Patent "2,758,549 RAILWAY TRUCK AIR SPRINGS RichardL. Lich, St. :Louis, Mo., assigu'or to General Steel Ciifinge'Corporatiou, Granit'e'City, 111., a corporation 0 111015 a I Application December 2, 1954, Serial No. 472,610 '15 Claims. '(Cl.105-'197)- The invention relates to railway rolling stock and more particularly to trucksfor lightweight railway cars embody-' ing elastic-walled air springsfor yieldingly supporting the truck frame and bolster from the axles and wheels.

In conventional heavyweight railway cars, where the ratio of light to loaded weight is relatively high, metal springs having a constant deflection rate are fairly satisfactory because there is little change in the natural frequency of spring oscillation between full-load conditions and no-load conditions. The present trend in railway passenger rolling stock is toward lightweight cars. In such cars the ratio of light to loaded weight is much lower than in heavy weight cars, with the result that metal springs of the type generally used inaconventional heavyweight cars do not provide desirable riding qualities under all load conditions, If such springs are designed to provide a smooth ride when the car is fully loaded, "they willnot provide a correspondingly smooth ride Whenthe vehicle is lightly loaded or unloaded, since good riding qualities are largely a function of the natural frequency of oscillation of the springs, which, in turn, is a function of deflection rate and load, and varies inversely with respect to the load, all other factors beingequal. For example, if a constant-deflection spring is designed to provide a desirable natural frequency for a loaded car, as the load is decreased or removed entirely, the natural frequencyincreases, with consequent deterioration in riding characteristics. Uniformly good riding characteristics can be provided for lightweight cars under all load conditions by using air spring systems, since such systems can be readily designed to provide a variable deflection rate which increases as the load increases, resultingin a substantially constant natural frequency throughout the load range. Furthermore, vin lightweight ears equipped with conventional metal springs, variations in loading cause large spring deflections with corresponding variations in coupler'height. The maintenance of standard couplerheight is of the utmost importance'in order that cars may be coupled to each other whenever desired, regardless of variations in loading. With air springs, simple mechanisms may be utilized to maintain coupler height substantially constant under all load conditions.

Air springs of the general type referred to have been suggested for use on railway trucks but in such fashion that the truck does not retain some desirable features generallypresent in conventional truck structures, such as stability of the truck bolster, a low center of gravity of the truck load-supporting member, and accommodation of relative movement of the truck load-supporting member and the truck running gear transversely of the frame to readily absorb and damp lateral forces when the truck passes from straight track to curved track and vice versa. Accordingly, it is the general object of theinvention to provide a truck :for lightweight railway cars in which a desirable spring frequency is maintained substantially constant-throughout the load range of the cars, and with which simple means may be utilized. for maintaining 2,758,549 Patented Aug. 14, 1956 coupler'height substantially constant regardless of loading.

A further objectof the invention is to provide .a truck adapted "to accommodateair-springs and their reservoirs and at the same time provide greater lateral and longitudinal stability than is provided by trucks heretofore adapted for use with air springs.

These and other detail objects of the invention are attained by the structures illustrated in the accompanying drawings, in which:

Figure l'is a top view of one longitudinal half of a railway four-wheel truck embodying the invention.

Figure 2 is atop view of the structure shown in Figure .1, the right hand portion of the drawing showing only the truck frame and theleft hand portion showing only the truck equalizers with equalizer spring seats.

Figure 3 is in part aside elevation and in part a longitudinal vertical section taken on the line 33 of Figure 1.

Figure '4 is a vertical transverse section taken on the line 44 of Figure Figure 5 is a detailed vertical transverse section taken on the line '5-5 of Figure 1.

Figure 6 is a side elevationlargely diagrammatic, of a truck embodying another form of the invention, 'a portion of the right hand end of the truck being sectionalized along the line 6' 6 of Figure 7.

Figure 7 is a transverse vertical section taken on the line 7-7 of Figure 6.

Figure 8 is a similar side elevation similarly sectionalized illustrating another form of the invention.

Figure 9 is 'a' similar elevation illustrating another form o'fthe invention.

The truck shown .in Figures 1-5 includes axles 1, 2 with

Wheels

3 and 4, respectively, and journal boxes 5 and 6, respectively. An equalizer comprising spaced bars 7 extends between the wheel axles and is of the type in which the end'portions of'the bars are elevated and rest upon the boxes and the intermediate portions of the bars are dropped to a lower level and extend to points adjacent the opposing faces offthe Wheel treads.

The axles are heldin spaced relation to each other and against substantial relative movement transversely of the truck by a rigid truck frame, preferably of one piece casting, having wheel pieces 8, transverse end members 9, and transverse intermediate transoms 10. The Wheel pieces are provided with depending pedestals 11, 12, slidably receiving journal boxes 5, 6 between them.

The truck frame is supported from the equalizers by upright coil springs 13, spaced apart lengthwise of the truck and mounted on seats '14 adjacent to the ends of the drop portion'o f the equalizer. Projecting outwardly and downwardly from each Wheel piece 8 is a bracket 15 alongated lengthwise of the truck and forming an upwardly facing seat for an air spring.

The air spring consists'essentially of a pair of elongated chambers 16, 17, having elastic walls and separated by an intermediate web 18 and forming a bellows-like structure capable of retaining 'air under compression and adapted to compress and expand vertically to absorb vertical load and shocks during operation of the vehicle. Preferably an air reservoir 19 is associated With each elastic wall chamber assembly and mounts'the latter on the truck frame bracket '15. Chambers 16 and 17 are interconnected by restricted ports 20 and the chambers are connected to reservoir 19 by suitable valves well-known in the air spring art which maintain air pressure in the overlie and receive the upper portion of air spring chamber 17.

This construction results in. a four wheel equalized truck with the truck frame supported at widely spaced points lengthwise of the truck to better resist galloping, the simultaneous rising of one end and lowering of the other end, and the truck bolster is similarly supported at widely spaced points lengthwise of the truck, whichincreases its stability lengthwise of the truck. The narrow elongated contour of the air spring and its mounting outboard of the truck frame and equalizers makes possible the support of the air spring at a low level inasmuch as the reservoir portion of the air spring is at substantially the same level as theequalizer coil springs.

There is no air spring structure inboard of the wheel pieces and equalizers to interfere with brake rigging and accordingly it is not necessary to increase the truck wheel base to accommodate the air springs. The narrow elongated formation of the air spring avoids such outward projection of the parts beyond the clearance limit line indicated at L. Preferably, the truck frame and bolster are held against movement longitudinally of the truck by a well-known anchor device 21, adapted to yield transversely of its length to accommodate relative vertical and lateral movements of the bolster and truck frame. The air spring will yield laterally of the truck to accommodate shifting of the bolster when the truck passes between curved and tangent track.

Figures 6 and 7 illustrate, largely diagrammatically, another arrangement corresponding generally to that shown in Figures 1-5 but differing therefrom in the provision of an air spring structure for supporting the truck frame on the equalizers 31. In this arrangement, two

air springs

32 and 33 are arranged end to end and lengthwise of the equalizer, each spring including elastic-wall pneumatic chambers similar to chambers 16 and 17, but shorter, and each having associated therewith an air reservoir 34 positioned between equalizer bars 31. This support of the truck frame does not affect the truck frame brackets 35, or the mounting of the air springs 36 thereon, or the support of the truck bolster 37 upon air springs 36.

Figure 8 illustrates another arrangement in which the truck frame 40 is supported from equalizer bars 41 by air springs 42 and the bolster 43 is supported from the truck frame by air springs 44, but the relative lengths of

air springs

42 and 44 are the reverse of the arrangements shown in Figure 6. A single elongated unit 42 is mounted upon the equalizers and a pair of shorter elongated units 44 are mounted upon the truck frame end to end lengthwise of the truck.

Figure 9 illustrates another arrangement embodying a combination of air springs and coil springs, as shown generally in Figures 1-5, but the elongated air spring unit is supported on the equalizer bars 51 and upright coil springs 52 spaced apart lengthwise of the truck are seated upon the bracket 53 projecting from the truck frame 54 and support the bolster 55 outboard of the truck frame wheel pieces and equalizer springs, as in the other arrangcments.

Each of the structures illustrated attain the advantages set forth in the introductory portion of the specification and it is obvious that the details of the arrangements may be varied other than as shown without departing from the spirit of the invention and the exclusive use of those modifications coming within the scope of the claims is contemplated.

What is claimed is:

1. In a railway truck, wheeled axles, an equalizer extending between said axles and supported therefrom at each side of the truck, yielding structure supported by each equalizer, a truck frame mounted on said yielding structure and including a wheel piece overlying the same and having a bracket projecting outwardly therefrom,

yielding structure supported by said bracket outboard of the equalizer, and a load carrying bolster mounted on said latter-mentioned yielding structure, at least one of said structures comprising an elastic-wall pneumatic chamber.

2. A railway truck according to claim 1 in which one of the yielding structures comprises a plurality of steel springs spaced apart lengthwise of the truck.

3. A railway truck according to claim 1 in which the yielding structure supported by the equalizer comprises upright coil springs spaced apart lengthwise of the truck and the yielding structure supported by the frame is a pneumatic chamber elongated lengthwise of the truck and corresponding in length approximately to the distance over the equalizer springs.

4. A railway truck according to claim 1 in which the yielding structure supported by the equalizer comprises an elastic-wall pneumatic chamber elongated lengthwise of the truck and extending substantially the entire distance between the adjacent wheels, and the yielding structure supported by the truck frame consists of a plurality of steel springs spaced apart lengthwise of the truck to bring them adjacent to the end portions of the elongated pneumatic chamber.

5. A railway truck according to claim 1 in which the yielding structure supported by the equalizer comprises an elastic-wall pneumatic chamber elongated lengthwise of the truck and extending substantially the entire distance between the adjacent wheels, and the yielding structure supported by the truck frame consists of a pair of relatively short similar chambers spaced apart lengthwise of the truck adjacent to the end portions of the elongated chamber on the equalizer.

6. In a railway truck, wheeled axles, an equalizer at each side of the truck extending between said axles and supported therefrom, yielding structure supported by each equalizer, a truck frame mounted on said yielding structure and including wheel pieces overlying the same, each provided with a bracket extending outwardly and downwardly below the level of the top of the yielding structure supported by the corresponding equalizer, yielding structure supported by each bracket, and a load-carrying bolster extending over the wheel pieces and mounted on the latter-mentioned yielding structures, at least one of said yielding structures comprising an elastic-wall pneumatic chamber positioned outboard of the equalizers and frame Wheel pieces.

7. A railway truck according to claim 6 in which the yielding structure supported by the equalizer comprises upright coil springs spaced apart lengthwise of the truck, and the bracket and the yielding structure carried thereby is elongated lengthwise of the truck to an extent corresponding to the distance across the upright coil springs on the equalizer.

8. A railway truck according to claim 6 in which an air reservoir is associated with the pneumatic chamber and is seated on the truck frame bracket.

9. A railway truck according to claim 1 in which an air reservoir is associated with the pneumatic chamber and carries the latter on the air spring supporting part.

10. In a railway truck, wheeled axles with journal boxes, an equalizer at each side of the truck extending between said axles and including relatively elevated end portions resting on the journal boxes and a relatively low drop portion extending substantially from alongside one wheel tread to alongside the other wheel tread, yielding structure supported by each equalizer adjacent to the ends of its drop portion, a truck frame supported by said structure over the ends of the equalizer drop portion, a yielding structure positioned wholly outboard of each wheel piece supported by the truck frame over the ends of the equalizer drop portion, and a load-carrying bolster having an end portion extending lengthwise of the truck and supported on said latter-mentioned yielding structure over the ends of said equalizer drop portion, at least one of said yielding structures comprising an elastic-wall pneumatic chamber.

11. In a railway truck, wheeled axles with journal boxes, an equalizer extending between said axles at each side of the truck and supported from the journal boxes, a rigid truck frame having depending pedestals slidably receiving all of said journal boxes and having wheel pieces extending between pedestals at the same side of the truck, yielding structures supported by each equalizer and supporting the truck frame at points near adjacent pedestals, there being a bracket extending outwardly from each Wheel piece and elongated lengthwise of the truck fora distance corresponding to the distance between the points of support of said frame, a rigid bolster extending transversely of the truck over the frame wheel pieces and having a relatively narrow vehicle-supporting central bearing andhaving relatively wide end portions outboard of the wheel pieces and extending lengthwise of'the truck a distance corresponding to the distance between the points of support of the truck frame, and an elastic-wall pneumatic chamber extending along the underside of each of said bolster end portions and resting upon the corresponding truck frame bracket.

12. In a railway truck, wheeled axles, an equalizer extending between said axles and supported therefrom at each side of the truck, yielding structure supported by each equalizer, a truck frame mounted on said yielding structure and including a wheel piece overlying the same, and provided with' a bracket extending outwardly and downwardly below the level of the top of the yielding structure supported by the equalizer, yielding structure supported by said brackets and comprising an elasticwall pneumatic chamber projecting upwardly above the level of the wheel piece, and a load-carrying bolster extending over the wheel piece and mounted on the lattermentioned yielding structure.

13. A railway truck according to claim 1 in which one of the yielding structures consists of a pair of devices spaced apart lengthwise of the equalizer and the elasticwall pneumatic chamber is elongated lengthwise of the equalizer bar and extends lengthwise of the equalizer throughout the distance between the axes of the spaced yielding structures.

14. A railway truck according to claim 1 in which each equalizer comprises a pair of bars spaced apart transversely of the truck, there being an air reservoir for the elastic-wall pneumatic chamber positioned between the bars. 7

15. A railway truck according to claim 1 in which each equalizer is of the drop type with a lower portion extending substantially from axle to axle and with upwardly offset end portions overlying the axles, each equalizer comprising a pair of bars spaced apart transversely of the truck, the elastic-wall pneumatic chamber extending substantially the full length of the lower portion of the equalizer, there being an air reservoir for the elastic-wall pneumatic chamber positioned between the equalizer bars.

References Cited in the file of this patent UNITED STATES PATENTS