US2403807A - Rail and joint structure - Google Patents

Description

July 9,1946;

H. L. LANSING 4 RAIL AND JOINT STRUCTURE 3 Sheets-Sheet 1 Filed Aug. 8, 1942 13 LToraceL July 9, 1946.

H. LANSING ,403,807

RAIL AND JOINT STRUCTURE Filed Aug. 8, 1942 3 Sheets-Sheet 2 INVENTORv flbraceL.LaJ1Jsi239,

July 9, 1946. H. L. LANSING RAIL AND JOINT STRUCTURE Filed Aug. 8, 1942 3 Sheets-Sheet 5 INVENTOR liar-ace Patented July 9, i946 UNITED, ,STATE RAIL AND JOINT STRUCTURE Horace L. Lansing,'Rutherford, N. J assignor to Poor & Company, New York, N. Y., a corporation of Delaware Application August 8, 1942, Serial No.. 454,169

I 2 Claims.

. t t 1 This invention relates to improvements in splice bar for connectingtogether the meeting end portions of railway rails, and to improved railjoints embodying saidimproved splice'bars.

The object of the invention, generally speaking,is to provide asplice bar of novel construction for cooperation in a novel manner with the rails which it isemployed to connect, whereby, in a joint embodying the improved splice bar, a condition approaching the Optimum of advantae geous stress distribution in both thesplice bar and the rail under both bolting and wheel load forces imposed onthe joint; is attained with the material advantage emanating from such stress distribution. 1

With the foregoing general objectin View, the invention consists in a splice bar having the novel features of construction, and in a railjoint embodying 'said bar having the novel features of combination and arrangement of parts, as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding 2 forms with said plane e an angle of not more than 17.

The under faces of the bases of the splice bars may; be formed in any suitable manner so that their contacts with the upper faces of the base flanges of the rails are within the limits stated. Moreover, the said contacts, designated at 2:, may be surface contacts of any desired widths within the limits stated, or they may be line contacts, or substantially line contacts. Preferably, however, they are line contacts afiorded by convexly curving the under faces of the splice bars transversely as illustrated in the drawings so that as the bars are drawn inwardly by the usual joint bolts I1, tendency of the bars to cock is minimized and proper seating of their bases upon the tops of the rail flanges is assured. As to the heads of the bars, these may have flat top faces or top faces of any other desired form engaging the or, alternatively and as is preferred, the upper inner'corners of the heads of the bars may be rounded and may have loading engagement with V the head fillets l8 of, the rails as, shown in the four photo-elastic studies. of rail joints. in which 1 t the splice bars have bearings upon the base flanges 0f the rail' within and outside the limits of the present invention for saidbearings.

Referring to the drawings in detail, A, A designate the meeting end portions of a pair of railway rails, each including, as usual, a head It, a web II and a base 12,-and B, Bdesignate a pair of splice bars connecting said rails together and each including, as usual, a head IS, a web l4 and a base l5. 1

In accordance with the invention the vunder face of the base ofeach of the splice bars B is suitably formed to have loading engagement initially with the upper faces of the related-flanges I6 of the rail bases solely between a plane aincludin the central, vertical, longitudinal plane of the web of the bar and a plane b including the inner face of the web of the bar. Also in accordance with the invention the said initial loading engagement between the base of each splice bar and the upper faces of the related flanges of the railbase is confinedbetween a pair of downwardly and outwardly diverging wheeleload-line-defining planesc and at both of which intersect the central, vertical, longitudinal plane e of the rails at thetops of the rails and the inner of which forms with said plane e an angle of not lessthan, 12 ,while the outer of which drawings. In any event-because of the initial loading cooperation of the bases of the splice bars with the flanges I5 of the rails within the limits stated, certain material and important advantages are attained. First, any tendency. of the bars to cook due to tightening of the joint bolt I! is minimized and proper initial seating of both the heads and the bases of the bars upon the head portions of the rails and the railflanges l6,"respectively, is assured as aforesaidJsecond, I

the setting up of lateral bending stresses in the webs of the rails under either bolt-tightening or wheel-load forces imposed on the joint are substantially entirely avoided; third, stresses in the heads, webs and bases of the rails are minimized and dangerous stress concentrations near the upper and the lower apexes of the joint bars are substantially entirely avoided, particularly if the heads of the bars have loading cooperation at their upper,.inner corners With the head fillets of the; rails as shown; fourth, tendency of the .rail flanges to droop under loads imposed on the joint are minimized; fifth, both bolting and wheel loads imposed on the joint are advantageously transmitted to the base flanges of the rails at the points of minimum eccentricity of both the rails and the joint bars, and, sixth, the bars are readily self-adjusting to fit with the rails and to compensate for the inherent rolling variations in the bars and the rails.

Experiments have demonstrated that a, rail jointin which the bases of the splice bars have line contact or narrow-width surface contact with the base flanges of the rails within limits as hereinbefore set forth afford an optimum of advantageous stress distribution in both the plice a u bars and the rails, and that shifting of said contacts either inwardly or outwardly beyond said limits results in progressive deterioration of said advantageous stress distribution. This is clearly evident from a consideration of Figs. 3 to 6 of the drawings which are reproductions of photographs of models of rail joints made from elastic material and subjected in each instance to the same load corresponding to the bolting load imposed on the splice bars and the rails in actual practice.

According to Fig. 3 the bases of the splice bars have loading engagement with the rail flanges to- 1 ward the heels of the bars beyond the inner limit of the present invention for said loading engagement. According to Fig. 4 the said loadin engagement is approximately at the inner limit of the present invention for said loading engagement. According to Fig. 5 the said loading engagement is approximately at the .outer limit of the present invention for said loading engagement. And according to Fig. 6 the said loadin engagement is outwardly beyond the outer limit of the present invention for said loading engagement. The reactance member IS. at the right hand side of each of Figs. 3 to 6 shows by the number of stress lines therein that the load corresponding to the bolting load imposed on the joint by the screw 23 was the same in each instance;

Several trends will be observed from Figs. 3 to 6. First, it will be observed that the regions of stress in the bases of the joint bars and the base of the rail retreat inwardly as the base bearin'gs of the joint bars upon the rail flanges move toward the heels of the bars from the inner limit of the present invention for said base bearings. Second, it will be observed that the amount of stressin the base of the rail increases as the base bearings of the joint bars upon the rail flanges move outwardly beyond the outer limit of the present invention for said base bearings, due to resulting droop of the outer portions of the rail base flanges. Third, it will be observed that the amount of stress produced in the webs of the joint bars also increases as the said base bearings moveoutwardly beyond the outer limit of the present invention for said base bearings. Fourth, it will be observed that the intensity of stress in the base-web connecting fillets of the rail also increases as the said base bearings move outwardly beyond the outer limit of the present invention for said base bearings. Fifth, it will be observed that the area of stress in the rail head decreases as the base bearings of the splice bars upon the rail flanges move outwardly beyond the outer limit of the present invention for said base bearings.

According to Fig. 3 the stress in the webs of the joint bars is a minimum, there is little stress due to droop of the base flanges of the rail and no stress in the toe portions of the splice bars. However, there are high stress concentrations at all bearing points due to the tendency of the splice bars to rotate outwardly at their heads and the bearings located as indicated are impractical as the heels of the splice bars are very close to'riding the base fillets of the rail.

Fig. 4, as compared with Figs. 5 and 6, shows lesser amounts of stress in the Webs of the splice bars, lesser amounts of droop of the baseflanges of the rail and no stress in the toe portions of.

the splice bars. Moreover, Fig. 4 demonstrates reduction in tendency, as compared with Fig. 3, of the heads of the splice bars to rotate out- 4 wardly and indicates practical take-up bearings of the bases ofjthe splice .bars. upon the rail flan es- I i;

Figure 5 shows the samecharacteristics as Fig.

- 4. A slight drooping of the rail base flanges may be observed together with a spreading of the stress patterns in the bases of the splice bars, but

the condition is very similar to the condition shown in Fig. 4.

Figure 6 shows a marked increase in the stress in the webs of thesplice bars and an increased tendency of the base flanges of the rail to droop, with increase of stress in the base-web fillets of the rail as well as increase in stress throughout the base of the rail. Figure 6 further shows the strain pattern spreading throughout the-entire base portions of the splice bars. I

In short, Figs. 3 to 6 of the drawings vividly indicate that a rail joint embodying splice bars having base bearings 'upon the rail base'flanges within the limits of th present invention afford a far superior joint as regards stress distribution than is afforded by a departure of said base bearings in either direction beyond said limits. These figures of the drawings also exemplify the improved results obtained by reason of the position of the point of contact of the bar on the upper flat fishing surface of the rail flange. That position is an important part of the present invention as certain desirable advantages are incident thereto. As herein noted the intensity of the stress in the base-web fillets of the rail increases as the base contact of the bar thereon moves outwardly beyond the outer limit of the present invention, and also the area of stress in the rail head decreases as such contact moves outwardly beyond the outer limit of the present invention.

By reference to photo-elastic study of Fig. 3 the bearing contact at the foot of the bar on the rail flange is well inside of the inner limit of the presentinvention resulting, as shown, in a heavy concentration of stress or strain in both the rail and the joint bar in the zone of contact; and in the photo-elastic study shown in Fig. 4 the point of contact between the base of the bar and the rail flange is farther out from the base web-fillet than shown in Fig. 3, showing a decided decrease in stress or strain within the base-web fillet, and also'in the bar. and inthe rail flange within the zone of contact. Thisrelative position of parts, as shown in Fig. 4, is within the scope of the presentinvention, and likewise the position of parts shown in Fig. 5 of the drawings, which represents what might be said an outer limit, as far as the joint bar is concerned, also shows reduction in stress or strain in the baseweb fillet over that shown in the example of. Fig. 3 and also in the stress ,or strain concentration within the zone of contact between the bar and the rail flange. The illustration of'Fig. 6 which definitely is outside of the limits of the present invention shows an extreme, but typical, advanced position, toward the outer edge of the rail flange, of the point of contact between the splice bar and the rail flange wherein the stress concentrations in the base-web fillet are materiall increased, aswell as a manifest increased drooping of the edges of the rail flanges.

Consequently, it will be seen that in order to obtain the maximum advantages of the use of the present invention with reference to minimizing of stress or strain in both the rail and the splice'bar, it will have been noted from what is said herein and whatisshown tliedrawings;

that the point -of contact for the joint bar on the flat upper fishing face of the rail flange,- is preferably at a point on said surface of the rail flange between the outer edge of the base webfillet and the longitudinal center of the said upper flat fishing surface of the rail flange. Also, it is shown, as essential to the present invention, that the loading engagement of the initial-contact bearing element with the rail flange is intersected by a plane at substantially right angles to the upper face of the rail flange and lies between a pair of downwardly and outwardly diverging planes, both intersecting the central vertical longitudinal plane of the rail atits top, at angles to said plane of the rail of not less than 12 for the inner plane and not more than 17 for the outer plane, thereby to confine the initial bearing element, and the major portion of the area-contact developed therefrom by abrasion, on the rail flange, between said diverging planes.

Prior to the development and utilization of the positioned curved base contact in accordance with the present invention, there was considerable difficulty in obtaining joint bars that had a reasonably good fit. With the advent of the higher rails the 112 and 131 R. E. due to increase in fishing height, the variations in fishing and angularity of the fishing surfaces became exaggerated- It was found that head contact bars developed the tendency to cook inward at the head. The result was the occurrence of a line bearing between the small upperouter fillet of the head of the bar and the head of the rail with a concentration of stress along this line and ultimately fatigue failures. With headfree bars either the initial contact occurred on the heel fillet, if the bar section was greater than the rail fishing, or at the outer edge of the toe, if the bar fishing was smaller than the rail fishing- In either case the stress concentration was at a most disadvantageous location. According to the present invention it was found that all of theseconditions were considerably improved by curving the base portion of the joint bar, and, in this connection, the location of the point of contact of this curve proved to be of vital importance. It was found that the position of contact advocated by the present invention gave the least disadvantageous distribution of stress in both the joint bar and rail. Also, it was found that as wear occurred and the initial line contact developed into an area contact of greater or lesser width according to the amount of wear, the contact remained in the zone where stress concentration isleast disadvantageous. It was additionally determined that, in order to insure against the development by wear of a shoulder on the rail flange, which might interfere with inward adjustment of the base portion of the bar to compensate for wear, it was necessary that the curvature of the underface of the bar be such that from its initial line contact with the upper face of the rail flange and from its subsequent area contact with the said upper face of the rail flange developed by wear, it should constantly recede upwardly and outwardly with reference to the upper face of the rail flange. In this connection the curved under face of the splice bar must extend inwardly at least to, but neednot extend inwardly appreciably beyond, th point where it contacts the upper face of the rail flange when the bar initially is applied, and, moreover, it must extend outwardly at least as far as, but not necessarily 6 beyond, the outer limit of the wear-developed contact area between the bar and the rail flange when the bar has been adjusted to its innermost limit relative to the rail to compensate for wear, Without further description it is thought that the features and advantagesof the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

' I claim:

1. A rail joint structure comprising vignoles rails and a splice bar, including a head, a web and a base, having loading engagement at its head with head portions of the rails and at the under side of its base with. the upper faces of the base flanges of the rails, the under face of the base of said bar being initially convexly curved transversely to a contour to have initial line .contact with the rail flanges between vertical f planes including the inner face and the center of the web of the bar, respectively, and between downwardly and outwardly diverging planes which intersect the central vertical plane of the rails at the tops of the latter and which are disposed at angles to said central vertical plane of the rails of not less than 12 and not more than 17, respectively, thereby to insure that initial and subsequent wear-developed contactbetween the base of the bar and the railflanges shall occur within limits transversely of the base of the bar and'the rail flanges where stress concentration is least disadvantageous, the said under face of the base of said bar from its portion in contact with the rail flanges constantly receding upwardly and outwardly with reference to the upper faces of said rail flanges to insure against development by wear of any shoulders in the upper faces of the rail flanges which might interfere with inward adjustment of the bottom portion of the bar relative to the rails.

2. A splice bar for connecting together the ends of vignolesv rails, said splice bar comprising a head to have loading engagement with head portions of the rails, a web, and a base having its under face initially convexly curved transversely to a contour to have initial line contact with the upper faces of the rail flanges between vertical planes including the inner face and the center of the web of the'bar, respectively, and between downwardly and outwardly diverging planes 7 which intersect the central vertical plane of the rails at the tops of th latter and which are disposed at angles to the central vertical plane of the rails of not less than 2 and not more than 17, respectively, thereby to insure that initial and subsequent wear-developed'contact between the base of the bar and the rail flanges shall occur Within limits transversely of the base of the bar and the rail flanges where stress concentration is least disadvantageous, the said under face of the base of said bar being curved to recede constantly upwardly and outwardly with reference to the upper faces of the rail flanges from the portion of said under face which contacts the rail flanges to insure against develop ment by wear of any shoulders in the upper faces of the rail flanges which might interfere with inward adjustment of the bottom portion of the bar relative to the rails.

' HORACE L. LANSING.

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