US2571475A

US2571475A - Leaf spring band construction

Info

Publication number: US2571475A
Application number: US632161A
Authority: US
Inventors: Michael V O'donnell
Original assignee: Crucible Steel Company of America
Current assignee: Crucible Steel Company of America
Priority date: 1945-12-01
Filing date: 1945-12-01
Publication date: 1951-10-16
Anticipated expiration: 1968-10-16

Description

Oct. 16, 1951 v Q'DQNNELL' 2,571,475

LEAF SPRING BAND CONSTRUCTION Filed Dec. 1, 1945 1515 15 Z INVENTOR.

MICHA EL v O'Do N N Patented Oct. 16-, 1951 UNITED STATES PATENT OFFICE I 2,571,475 LEAF SPRING BAND CONSTRUCTION Michael v. O'Donnell, Pittsburgh, Pa., assignor to Crucible Steel Company of America, New York, N. Y-, a corporation of New Jersey Application December 1, 1945, Serial No. 632,161

1 Claim. 267-52) This invention relates to multi-leaf elliptic springs and the like, and more particularly to the leaf-retaining metal band employed at the center of such springs for containing the spring plates and holding them in position in integral assembly. The invention is an improvement on such spring bands as heretofore produced, and upon the methods heretofore employed for fabricating the same.

One object of the invention is to provide a stronger spring band than heretofore, and one which is free from the forging strains and cracks such as are frequently encountered in such bands as made by prior methods.

Another object of the invention is to provide a spring band which can easily be adapted to fit the requirements of a number of springs of different designs. In accordance with this objective, the invention provides a spring band construction and method of fabrication, whereby a spring band may be produced in a size adapted to suit the greatest dimension of a group of springs of various sizes, and capable of being easily adapted to fit the smaller sizes in the group.

Spring bands, especially those employed for the elliptic springs used in railway car and locomotive constructions, serve two purposes: First, they contain and hold the superimposed spring plates in proper position in integral assembly; and, secondly, one end of the spring band, in contacting the spring seat, transmits the spring load to the spring seat and takes the Wear due to this contact. Because of this, the end of the spring band which contacts the spring seat is always made of a greater thickness and weight of material than is the other end and the two elongated sides of the band. How much greater this thickness is depends to some extent on the judgment of the designer of the spring and also on the thickness of the spring seat. For this reason, spring bands as designed by different desi ners to contain the same number of spring plates of the same size, may vary in thickness of the end of the band contacting the spring seat. This makes it necessary for the spring manufacturer to produce such spring bands in small quantities to suit the individual requirements of each purchaser.

In accordance with the practices heretofore in vogue, such spring bands have ordinarily been produced, by starting with a flat, rectangular steel plate, having a thickness equal to the thick end of the finished band. and other dimensions as required by the size of the finished article. The spring band is produced from this flat plate by forg t pp site ends thereof to the thickness required by the sides and opposite thinner end of the band, leaving, however, the central portion of the plate unforged up to a width corresponding to the thick end of the finished band. The forged ends are now bent downwardly at right angles to the thickened central section, and the ends thereof are curled inwardly toward each other until they contact, whereupon the curled ends are squared off and the contacting edges welded together to provide the desired open-ended, rectangular contour of the finished band. The above manufacturing steps are carried out under a forging hammer, which imposes severe forging strains in the metal, and often produces cracks and fissures in the metal, particularly in the regions where the forged ends are bent at right angles to the thickened central por-- tion. Moreover, the band as thus produced is suited for a spring of but one design.

In contrast with the prior practice of making spring bands as outlined above, the process-0i the present invention starts with a flat, rectangular metal plate having a substantially uniform thickness corresponding to the thinner sides and end of the finished band, the other dimensions of the plate, i. e., width and length, being selected to produce a resulting band of desired dimensions. This fiat plate is thereupon press-formed into a substantially rectangular tubular configuration, coniorming in length and width to the finished band, and with the opposite ends of the metal plate abutting each other along the median line of one of the ends of the so-formed rectangular member. A rectangular plate having a thickness preselected as noted below, and a width and length corresponding to the aperture width and length of the rectangular tubular member, is now inserted therein in overlapping relation to the aforesaid abutting ends, whereupon this plate is welded in position and at the same time the butting ends of the rectangular member are welded together.

The plate thus inserted and welded in position is referred to herein as a filler plate and serves, in one of its functions, to impart to one end of the resulting spring band the additional thickness required for wear-resisting and loadcarrying purposes above stated. Also, it serves to strengthen and reinforce the end of the resulting band which contains the weld seam of the originally abutting ends.

In accordance with a feature of the invention as above noted, the rectangular spring band member can be made of a width and length to accommodate a number of different spring designs,

56 wherein the leaf springs, although of the same width, vary in number, or in aggregate sectional length in the vertical direction, the differences between this dimension and the aperture length of the spring band being accommodated by employing filler plates of different thicknesses to fill up any space remaining between the leaf assembly and the spring band.

By employing the spring band construction and method of fabrication above outlined, no abnormal stresses are imposed by the press-forming operation, resulting in a spring band which is considerably stronger for given dimensions than is obtainable under prior practices.

Referring now to the annexed drawing:

- Fig. 1 is a vertical elevation, shown more or less diagrammatically, of a part of a locomotive assembly showing an elliptic spring mounted in operative position, with its spring band resting on the spring seat; while Fig. 2 is a section at 22 of Fig. 1.

Figs. 3 to 7 inclusive are perspective views illustrating the successive steps employed in producing a spring band in accordance with this invention; Fig. 3 showing the flat metal plate of requisite dimensions used as the starting material; while Figs. 4 and 5 illustrate the results of the successive press-forming operations employed for converting the flat plate of Fig. 3 into the substantially rectangular tubular member above referred to. Fig.0 shows the filler plate, and Fig. 7 the completed spring band comprising the Fig. 5 construction with the filler plate incorporated therein.

Referring for the moment more particularly to, Figs. 1 and 2, there is shown a portion of a locomotive truck I supported on a car wheel 2,

the truck in turn mounting a spring seat 3, on which rests the thickened end I of a spring band I of an elliptic spring shown generally at 8, and comprising a stack of superimposed spring plates 1, retained in integral assembly within the spring band 5. A body portion of the locomotive to be resiliently supported (and not shown because no part of the invention) is secured to a member I fulcrumed, as at 9, to one end of the elliptic spring 6, the opposite end of the spring being fulcrumed, as at ID, to one end of a tie rod ii, the opposite end of which is pin-connected, as at II, to the truck I.

Referring more particularly to Figs. 3 to 7 inclusive, the spring band 5 of Figs. 1 and 2 is constructed as follows: A rectangular steel plate It, Fig. 3, of the required length and width, and of the thickness indicated at H, Fig. 2, is initially press-formed to the configuration shown in Fig. 4 wherein the opposite ends l5, ii of the plate I! are bent downwardly, at right angles to the body portion of the plate, as indicated at I 5 and II in Fig. 4. The Fig. 4 construction is again pressformed to the substantially rectangular tubular form shown in Fig. 5, comprising the upper end l1, side walls It and I9, and lower end consisting of the abutting end portions l5 and IS. A filler plate 29, Fig. 6, having the desired thickness as aforesaid, and a width and length corresponding to the width and length of the aperture 2|, Fig. 5, ofthe rectangular member, is thereupon disposed within the rectangular member in'overlapping relation to the abutting ends Ii, ll, as illustrated in Fig. 7. Thereupon, the filler plate 20 is welded in place as shown in Fig. 7, and at the same time the abutting ends ii, I. of the rectangular member are welded together as indicated at 22 to provide the finished spring band.

As above stated, the vertical height of the rectangular member, Fig. 5, may be made such as to accommodate a series of leaf spring designs of diilferent sizes, the individual spring plates of which have the same width, but vary in number or in thickness in superimposed assembly, in which event the thickness of the filler plate 2| is so chosen as to take up whatever space remains in a particular design, between the aggregate height of the leaf spring assembly and the aperture height of the rectangular member, Fig. 5. In this way, and by employing filler plates of various thicknesses, the same spring band design may be employed for the various spring designs referred to.

I claim:

A'spring band for retaining a stack of spring plates in integral assembly, comprising a substantially rectangular tubular member consisting of a rectangular metal strip of uniform thickness,

, shaped into said tubular contour with the opposite edges of said strip butt welded together, a metal filler plate of uniform thickness disposed within said tubular member and spanning the full aperture width thereof and extending the full length thereof in overlapping relation to said butt weld, said plate being welded to said tubular member, and said plate being of a thickness preselected to provide a resulting inner aperture of said tubular member conforming substantially in cross-section to the cross-section of the spring plate assembly to be retained therein.

- MICHAEL V. O'DONNELL.

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,581,916 Broussouse Apr. 20, 1926 2,095,585 Yates Oct. 12, 1937 FOREIGN PATENTS Number Country Date 470,066 Great Britain Aug. 3,1937

OTHER REFERENCES Laminated Springs by T. H. Sanders, Bpon and Chamberlain, 123 Liberty St., New York, pages 478, 479 and 490. (Copy in Div. '45.)

The Welding Encyclopedia, 9th edition, edited by S. Plumley, The Welding Engineer Publishing Co., 608, S. Dearborn St., Chicago, Ill., page 481, Figure H. (Copy in Division 14.)