US2793816A - Rail joint - Google Patents

Description

May 28, 1957 H. L. LANSING RAIL JOINT 5 Sheets-Sheet l Filed Oct. 3, 1951 INVENTOR May 28, 1957 H. L. LANSING RAIL JOINT 3 Sheets-Sheet 2 Filed 001;. 5, 1951 INVENTDR Horace L. Lens;

ATTORNEY y 1957 H. L. LANSING 2,793,816

RAIL JOINT Filed Oct. 3, 1951 3 Sheets-Sheet 5 INVENTOR Horace L. Lansing.

ATTORNEY United States Patent ice RAIL JOINT Horace L. Lansing, Rutherford, N. J., assignor to Poor & Company, Chicago, 111., a corporation of Delaware Application October 3, 1951, Serial No. 249,572

1 Claim. (Cl. 238243) This invention relates to rail joints, and more particularly to a joint including bars which will minimize the critical stresses in the rail resulting from the wedging action of the joint bars caused by bolt tension.

According to the usual custom, rail joint bars for securing rail ends together are subjected to bolting forces of considerable magnitude which wedge the bars in the fishing space of the rail with the result that the head and base portions of the rail are forced apart with consequent great stress which tends to set up cracks or fissures in the rail in the zone of the joint. As wear ocours in the joint, the resulting looseness must be taken up by retightening the bolts so that the rail is again subjected to great stress. Usually, space is provided between the rail ends to permit relative movement between the rails and the bars, and in some cases lubricant is applied between the contacting surface of the bar and rail to permit them to more freely move. In any event, the relative movement referred to is one of the causes of wear between the bars and the rail and thus must be taken care of by periodically tightening the bolts as a part of track maintenance which is a costly item in servicing track.

The welding of rail ends together is an example of an attempt to avoid wear and the maintenance cost in connection therewith, but welded rail has numerous disadvantages, particularly in initial cost, difiiculty in repairing the breaks, and the cumbersomeness and expense of moving it from one location to another.

Accordingly, the present invention has primarily in view what may be termed a frozen joint so that jointed track structure will have all of the advantages of welded rail without its disadvantages. The reason that more serious attempts have not been made to intentionally freeze joints is that normal joint bar sections of either the headfree or head-contact type create dangerously high stresses in the rail due to the wedging action of the joint bars. In accordance with the present invention, however, it is proposed to so form the joint bars as to greatly minimize the stress produced by bolting the bars to the rail.

More specifically, the present invention is directed to a joint bar provided at its inner side with a web-engaging stop portion at the region of the bolt holes and the neutral axis of the bar. In that connection, the invention is adaptable to bars of both the head-free and head-contact type.

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings in which:

Figure 1 is a vertical half-section view of a head-free type of joint bar embodying the present invention.

Figure 2 is a view similar to Figure 1, illustrating the application of the invention to a bar of a head-contact type.

Figure 3 is a photoelastic study of the bars shown in Figure 1 assembled to a rail and subjected to a small amount of bolt tension.

Figure 4 is a photoelastic study of the same bars shown in Figure 3 subjected to three and one-half times the bolt tension of the barsin said Figure 3.

Figure 5 is aphotoelastic study of the bars shown in Figure 2 applied to a rail with a small amount of bolt tension.

Figure 6 is a photoelastic study of the assembly of Figure 5 wherein the bars are subjected to a bolt tension three and one-half times greater than the bars shown in Figure 5. Figures 7 and 8 are photoelastic studies illustrating the stress pattern in the bars and rail of a conventional head-free joint where the bolt tension is increased in Figure 8 to three and one-half times that shown in Figure 7.

Figures 9 and 10 are photoelastic studies illustrating another typical joint of the head-contact type wherein the joint assembly of Figure 10 is subjected to three and one-half times the bolt pressure shown in Figure 9. Compare Figure 10 with Figure 6 of applicants invention involving a head-contact bar.

Similar reference characters designate corresponding parts in the several figures of the drawings.

Referring first to Figure 1, the rail designated generally as R is provided with a joint bar A having a head portion 1 and foot portion 2 connected by a web 3. The head -1 is provided with an upper rail cont-acting surface 4 which engages the fillet-at the underside of the rail head while the upper surface 5 of the bar stands free of the underside of the-rail head. The drawings show the so-called toeless type of bars by way of illustration and not by way of limitation. The invention applies equally well. to flanged bars, that is bars having a base flange engaging the upper side of the base flange of the rail.

The web 3 is provided at its inner face in the region of the bolt holes and the neutral axis of the bar with an inwardly extending abutment or stop 6 intended to have a bearing with the surface 7 of the web when the bar is in final bolted position. Initially, as shown by dotted lines, the web engaging face of the abutment '6 has sufficient clearance from the web to enable the bar to be drawn in final seating position as shown in full lines under additional bolt pressure. Thereafter, the head and foot of the bar maintain a predetermined constant pressure on the rail ends sufficient to maintain them in adequate and proper alignment and supply adequate support. The shape of the abutment is preferably as shown but it may be of any desired profile so long as it is located in the region of the bolt holes of the rails and bars and the neutral axis of the bars. Moreover, the abutment may be continuous throughout the length of the bar or it may be intermittent, that is formed at the location of the bolt holes with intervening spaces therebetween.

(In Figure 2 the bar A is a head-contact type of bar having the same general structural characteristics as the bar A described in Figure 1. However, in this case the upper surface 5a of the head of the bar engages directly with the tangent portion of the underside of the rail head while the surface 2a at the foot of the bar engages the upper surface of the rail flange in the usual manner. The inner face of the bar A is provided with an abutment or stop 6a for engaging the related surface of the web of the rail when the bar is drawn to its final position under bolt pressure.

The abutment or stop portion 6 or 6a is preferably Patented May 28, 1957 formed continuously throughout the inner face of the bar for convenience in rolling and to equalize and dis tribute the bolts pressure uniformly between the bar and the rail.

In applying bars embodying the present invention to railway track the rail ends may be butted together to thereby avoid wheel batter in the rail ends while at'the same time the rail ends are frozen in the joint to avoid relative movement causing wear. Thus, a frozen joint is provided at the time of initial installation with the accruing advantages of welded rail, while at the same time track may be serviced, when required in the same manner as conventional jointed rail. Moreover, abutment 6 or its equivalent in the region'of the bolt holes and the neutral axis effectively prevents dangerously high stresses in the rail embraced by the joint which is recognized to be the cause of much breakage in rails at joint locations.

For example, reference is made to Figure 3 showing a photoelastic study of a bar according, to Figure 1 subjected to a small amount of bolt tension. Figure 4 shows the same bar with three and one-half times the tension shown in Figure 3. A comparison of these figures shows that there is no appreciable increase in the stress pattern of the rail.

Figures 5 and 6 show the same comparisons for the bar shown in Figure 2. In Figure 6 with the bar under increased tension, there is no appreciable increase in the stress pattern of the rail.

Figures 7 and 8 illustrate what happens in a conventional head-free joint where bolt tension is increased'three and one-half times. Figures 9 and 10 illustrate a similar comparison in bars of the head-contact type. The increased stress in the rail is apparent in Figure 10, as compared with Figure9.

Compare the low stress patterns of the rails of Figures 4 and 6 using bars of Figures 1 and' 2, respectively, under increased bolt tension, with the rails of Figures 8 and 10 with conventional head-free and headcontact bars where such bars are under equal bolt tension and the excessive stresses in the rails are manifested in the numerous fine lines which do not exist in Figures 4 and 5.

*I claim:

A rail joint including rail-ends, joint-bars, and bolts for freezing said ra-il ends together, in situ, at the time of installation and also minimizing critical stresses in the web, the head-web and base-web fillets of the rails, due to wedging action of the joint-bars in moving to seated position, in the fishing space of the rails under bolt pressure, comprising; joint-bars each having head and foot portions seated to initially engage at least a portion of the underside of the rail heads and the upper sides of the base flanges of the rails, respectively,

and connected by a web normally unfiexed when such initial engagement occurs, and an over-stress preventing abutment portion integral with and at the inner face of said joint-bar web and having a rail-web engaging stop face offset from the inner side of the bar in the region of all of the bolt holes between said head and foot portions and disposed in the neutral axis of the bar, said abutment being of a transverse width to have its stop face stand free of the rail web when the head and foot portions of the bar are initially seated against related parts of the rail ends, and whereby, when continuing boltclamping pressure is applied at the region of the abutments, the stopface will advance to contact the railweb toarrest further stresses in the rail heads and base flanges of the rail-ends.

References Cited inthe file of this patent UNITED STATES PATENTS 461,088 Wiley Oct. 13, 1891 834,292 Gillchrist Oct, 30, 1906 979,860 Huse, et a1 Dec. 27, 1910 1,054,843 Heinle Mar. 4, 1913 1,110,291 Keller Sept. 8, 1914 1,258,249 Roach Mar. 5, 1918 1,611,168 Dishong Dec. 21, 1926 1,737,669 Northey Dec. 3, 1929 2,021,297 Faries Nov. 19, 1935 2,170,018 Gadd Aug. 22, 1939 2,204,304 Gallagher June 11, 1940

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