US1735347A - Rail joint - Google Patents

Description

Nova 12, 1929.

E. W. CARUTHER5 RAIL JOINT Filed May 9, 1928 2 Shams-Shem l Patented Nov. 12, 1929 PATENT OFFICE EUGENE w. oanu'rnnns, or SECALNE, PENNSYLVANIA.

RAIL JOINT Application tiled Kay 9, 1928. Serial No. 276,347.

My invention relates to splice bars for use in tying together the adjoining ends of the rails of railroad tracks.

One purpose of my invention is to give the head of a splice bar a contour that will insure a live joint between the bar head and rail head even after the bar has from long service worn inwardly to a seat against the web of the rail.

A further purpose is to avoid permanent engagement between the bar head and rail fillet even after the bar has from long service worn inwardly to a seat against the web of the rail.

A further purpose is to change the vertical alinement of a splice bar after its head portion has worn to a seat against the web of the rail, drawing the foot ortions of the cooperating bars inwardly event an abutment 20 below the rail lillet as an axis and thereby free the engagement between the rail fillet,

and the bar head and maintain a live joint between the bar and rail where formerly the joint has become permanently dead as soon as the bar head reaches a seat on the web of the rail.

A further purpose is to" relieve the lower portion of the base of the bar so as to adapt it to move inwardly afterthe top of the bar has found a seat against the web of the rail.

A further purpose is to accommodate the.

sectional area of the track bolts which unite cooperatin splice bars to the length of the bolts, there y maintaining any desired definite strain for a given bolt tension irrespective of bolt length.

A further purpose is to provide interfittin arcuate bearing surfaces between the bee and nut or washer portions respectively of 49 a bolt member and the cooperating splice bars tied together by the bolt to form a rail joint, I may make the interfitting arcuate bearing surfaces either spherical or cylindrical and may locate these bearing surfaces between the head of the bolt and the outside of one splice bar at one end of the bolt and between the cooperating splice bar and a nut or a washer beneath a nut at the other end of the bolt. r

A further purpose is to vary the contour of the splice bars according to service conditions and also according to the material of the splice bars and of the rail.

A further purpose is to lessen the requisite sectional area of track bolts by lessening the distance between the web portions of the cooperating splice bars. I thus lessen the cost of track bolts by providing a contour of splice bar that permits the use of smaller and shorter bolts than have hitherto been considered necessary. A further purpose is to provide the nuts of track bolts with extension portions for wrench holding thereby permittin thq use of greater outward extension of the cod portion or foot portion, either or both, of the splice bar without interfering with the adaptation to easy tightening of the nuts.

A further purpose is to provide 9. splice bar with a contour that will adapt it to pivot slidingly upon the web portion of the rail at the inside lower edge of the bar head after the her head has worn to a seattagainst the web, resulting in a slight canting and upward movement of the bar so as to support the lower portion of the rail head at a point out from the rail fillet.

A further pur ose is to maintain supporting engagement etween the under side ofa" rail and the head of a splice bar at points outwardly from the rail fillet while the bar head is finding a seat against the rail web.

Further purposes will appear in the specification and in the claims.

While I show my invention in forms that differ in detail, as with respect .to the bolt connection between the cooperating splice bars, size and contour of bar foot and location of her web with respect to its distance from the rail web, I have elected to illustrate the invention with but a single contour of rail and but a single contour of inwardly presented surface on the bar head Figure 1 is a vertical section through. a. rail joint embodying my invention, showing the splice barsinthree positions.

Figure 2 is a reduced scale broken topplan view of structure shown in Figure 1.

Figures 3 and 4 are crosssections corre we -.produced undesirable dead? joints from the b sponding generally with Figure 1 but showing slightly modified forms.

Figures 5, 6, 7, 8 and 9 are fragmentary views illustrating different forms of arcuate connections between the splice bar and the nut and bolt membersat the nut end of the bolt, each of the forms shown having certain advantages that may under certain conditions make it desirable as compared to any of the others illustrated. v

Figure 1 shows a form of splice bar very similar in general appearance to one that has hitherto been widely used, but from which it differs at the head to prevent the head from wearing to a dead seat against the rail head fillet, and diilers at the foot to permit the foot to wear inwardly after the head has worn to a seat against the rail web.

The figure shows the bars in three positions, a full line contour showing the rails in their initial positions, a dot-and-dash line contour showing the position of the bars when they have worn horizontally inwardly to seat against the rail web, (after perhaps two to three years of service,) and a dotted line contour showing their canted position at a considerably later period, with a freed rail fillet and a live bearing under the rail head.

Lihe'numerals refer tolike parts in all figures. r

Describing in illustration and not in limitation and referring to the drawings in the past splice bars have been given a form such that thesplice bar headsafter a period of considerable service find permanent seats against'the rail head fillets, This has time that the bar heads wear into engagement with the rail fillets, dead joints being joints that do not adequately support the under side of the rail head at points out beyond the rail fillets. The wedging action of the support has been lost. j

One of the principal objects of my invention is to prevent the rail heads from wearing into dead seats against the rail fillets and by this means to maintain a supporting engagement under the rail head at points further out than the rail fillet and thereby to increase materially the efiective life of the joint. l

In Figures 1 and 2 adjacent ends of rails 10 and 11, supported upon suitable tie-plates 12 and i3 and ties i4: and 15, are held together intermediate the ties by preferably interchangeable splice bars 16 and track bolts 1?.

The rails 10 and 11 are shown of a weil known type and the splice hare 16ers shown with a sectional contour that is very similar I in general appearanceto that or a type of splice bars that has heen widely used the,

past.

The illustrated contour only slightly from that or tneprior art, dieters in way that results in a material increase in the eifective life of the bar.

I have extended the lower part of the bar head 18 somewhat inwardly to provide a fulcrum19, in position to ultimately engage the rail web 20 of the rail.

1 have also decreased the outer curvature of the head portion '21 that is presented to ward the rail fillet 22 making its radius of curvature as great as or greater than the radius of curvature of the fillet 22, and have also made the lower contour of foot 23 of the bar such as to adapt the foot to gradually ride inwardly up the flange portion 24 of the rail after further inward movement of the bar head has been stopped by the bar head engaging the rail web.

The forward relief of the foot at 25 should be sufficient to permit the more nearly central portion 27 to ride up the rail flange and in the same way the outer relief at 26 should be sufiicient to avoid locking the bar from vertical canting.

'top of the rail flange at a relatively considerable distance from the rail web.

After the joint has been in service for a considerable period during which period the bolts have been periodically tightened the spliced bars will occupy somesuch position as that indicated by the dot-and dash line 29, the caring surfaces between the rail head and bar head and between the rail flange and bar foot having progressively worn away until the bar head finds a seat against the web of the rail as indicated in the dot and dash line.

In the illustration the adjoining contours of the rail head and bar head are coincident, the curved portion 21 of the bar head temporarily fitting the fillet 22 of the rail.

Optionally the radius of curvature of the bar headicontour at 21 maybe made greater than that of the rail fillet in which event the two surfaces will never quite coincide but I prefer to make the curvature of the bar head at 21 as small as but no smaller than that of the rail fillet.

I make thisradius of curvature at least as small as that of the rail fillet in order that the rail fillet may never determine the inward position of the head, a condition that has existed with the bars of the prior art after the bars not much smaller than that of the fillet be--.

cause this would mean an unnecessary elimima am nation of metal from points on the head relatively far from the neutral axis of the bar.

The dot and dash position corresponding to line 29 may be considered as a temporary one that the bar occupies for a short perir d before it begins to be canted by inward travel of the foot after the corresponding inward travel of the head has been stopped by an engagement between the bar head and rail web.

Further wear and additional tightening of the bolts results in drawing the lower portion of the bar inwardly with respect to the upper portion until the bar occupies some such position as that indicated by the dotted line 30.

The result of thus moving the bar foot further in than the baehead is to relieve the engagement between the curved portion 21 of the bar head and the rail filler. This may be seen by examination of the dotted line 30 which shows the curved portion of the head at some little distance from the fillet.

The exact position of the upper surface of the bar head and of the lower surface of the rail will vary with variant service conditions and for this reason the illustration should be taken as merely a diagrammatic one to bring out the fact of the freeing of the rail fillet and the maintenance of engagements between the rail and bar head upon each side of the fillet but not at the fillet.

It will be seen that the de'ad connection between the bar head and rail fillet is avoided, the rail head being effectively supported at points further out than the fillet and the eftective life of the joint is materially increased. I

If the bearing surfaces between the bars and bolt members are flat, one flat surface 31 (Figure 1) of one bar supporting a flat surface 32 under the bolt head 33 while the corresponding flat surface on the other bar supports a flat surface 34 under a bolt washer 35, then any relative canting of the bars, produced by tightenin the bolts with inward movements of the cot portions of the bars without a corresponding inward movement of the bar heads, will stretch the upper fibers of the bolts more than the lower fibers and thereby produce greater stresses in the upper bolt fibers.

I preferably provide interfitting arcuate bearing surfaces between the bolt head and one splice bar and the bolt nut or bolt washer and the other splice bar to avoid these uneven stresses and strains when the bars are canted vertically to maintain live joint connection between the ma heads and bar heads.

I have not illustrated these interiitting arcuate connections in Figure 1, which is intended primarily to illustrate the canting of the bars and the maintenance of the live head support. A bar of the'prior art is there mod1- fied to embody some of the features of my 1n vention, but without effecting much change in the sectional contour and placement of metal.

This general type of bar has been built upon the theory that the upper and lower section moduli of the bar should be substantially equal. My invention applies whether this be true or not and hag-therefore, been applied to both forms.

It will be'understood that the strength of the upper portion of the bar may be considered as determined by the upper section modulus,which is themomentof inertia of the whole bar, divided by the distance from the horizontal axis passing through the center of gravity to the extreme upper fiber, and that the strength of the lower portion 0'? the bar is determined by the lower section modulus, which is the ratio between the same moment of inertia of the whole bar, divided by the distance from the same horizontal axis pass ing through the center of gravity of the bar to the lower extreme axis.

I have discovered that this theory that the upper and lower section moduli of the section should be substantially equal is basically incorrect and that as a matter of fact in any usual conditions of service the head portions of the bars should be considerably stronger than the foot portions it the two are to wear out simultaneously and have disclosed and claimed bars having a greater upper section modulus-than lower section modulus in an appliclation, Serial No. 276,348, copending herewit 1.

Fi ure 3 shows a bar substantially like that of Flgure 1 except that the outwardly extending flange portion 36 of the foot has been removed to a point even with the outside edge of the rail flange and also in that the bearing surfaces between the bars and bolt members are interfitting arcuate surfaces instead of flat as in Figure 1. f

The effect ofcutting oil a major portion of the flange 36 is to raise the center of gravity of the bar and to make its lower section modulus less than its upper section modulus, both of which I have found desirable. However cutting off the outer portion of the flange correspondingly weakens the foot flange in so far as it is used to prevent any distortion of the bar when the bolts are tightened.

The arcuate interfitting surfaces between the bolt member and the respetcive bars may be either spherical or cylindrical, either form having certain advantages and in certain cases being most desirable, and both forms permittingthe bars to cant without an introduction of uneven stresses and strains either in the bolt or in the bar members.

An arcuate cylindrical concavity 37 along the outside of the splice bar web gives a section that is easily rolled and that has a minimum thickness along the middle or" the web, which is in accord with an efiicient placement of the metal of the flange.

The convexly curved spherical bolt head surface 37 fitting one cylindrical surface and the c'onvexly curved spherical washer surface 37 2 fitting the other cylindrical surfaces are also surfaces very easily formed when manufacturing the bolts and washers respectively.

The interfitting cylindrical bearing surfaces are of course not adapted to relative r0- tation so that washers are needed under the nuts when this type of web and bolt bearing connection is used.

There are some advantages in making the in'terfitting arcuate bearing surfaces between the bolt members and bars spherical instead of cylindrical and when this is done the washer under-the nut may be omitted, the inner end 39 (Figure 6) of the nut being formed with a spherical bearing surface to seat in a spherical depression on the web of the bar. The bolt must then be of non-circular section to prevent turning in a non-circular bar opening. I

The omission of the washer shortens the distance between the nut and head of the bolt, thereby proportionately lessening the total longitudinal strain or stretch of the bolt I sulting in a very live joint.

On the other hand when the bolts are made of a more usual stock that is only imperfectly elastic, they take a permanent set when tightened and it is then desirable to limit the bolt elongation to a definite value, in that this limits the undesirable permanent set of the bolt. It will be evident that the total permanent set of a bolt incident to a given total pull will vary directly with the effective length of the bolt and that a shorter bolt should also be sectionally smaller if the permanent set of the bolt is to be the same as that of the longer bolt.

I may accommodate the sectional area of the track bolts to their effective length, using shorter and optionally smaller bolts when conditions are such that it is desirable to limit the totat elongation of the bolts when the nuts are'tightened to a definite value, or using longer bolts when conditions make it desirable to'have a fairly high elongation, which is usually only the case when the material of the bolt is such as to very perfect- 1y maintain strict proportionality between longitudinal stress and longitudinal stretch without any substantial permanent set when the stress has been removed.

It may sometimes be desirable to reduce the stress in the bolts to a definite value below which it has been found stress and strain are substantially perfectly proportional and in the joint by increasing the bolts elongation.

When conditions make it desirable'to use long bolts I may use washers under the nuts, as in Figures 3, 4, 5 and 8 and use a form of splice .bar having web portions spaced far from the web of the rail as in Figure 3, while if conditions are such as make it desirable to use short bolts, I avoid the use of washers (Figures 6 and 7), and form the splice bars with webs relatively close to the rail web.

It will be seen that the spherical bearing surfaces between the bar and nut members are preferable when shorter bolts are desirable.

, It is obvious that the advantage of making "the bearing surfaces. between the bars and bolt members of an interfitting arcuate contour is one that avoids uneven stresses and strains in the bolts and in the webs of the bars when the bars are relatively canted and also one that avoids uneven stresses in the'bolt if the bolt becomes bent, which is not at all unusual.

Bolts become bent during service most fre quently in a direction longitudinal of the rail,

the bending being due to stresses tending topull the rails apart longitudinally.

When a bolt becomes bent longitudinally of the rail the spherical seating of the nut and head members is preferable to the cylindrical,

in that the spherical seating more effectively avoids uneven stresses and strains when the bolts are tightened.

In the form shown in Figure 3 the strength of the head of the bar is materially greater than that of the foot. There are very heavy shear stresses upon the portions of the bars that are at the ends of the rails. I

If these shear stresses are perfectly supported, the functioning of the splice bars as earns subjected to bending moments first up and then down is to a considerable extent avoided. .For this reason, and also for the reason that the stresses on the bar are to a very considerable extent the result of blows or sudden impacts, the section modulus of the upper portion of the bar needs to be under usual conditions of service considerably greater than that ofthe lower.

- The head has to be strong enough to stand up under impact stresses and blows that have a relatively smaller effect at the foot portion of the bar.

Both the head and foot musthave a very considerable strengthagainst horizontal discenter 0 gravity of the bar.

This strength in horizontal direction should be suflicient to prevent any distortion of the bars along their lengths incident to tightening the bolts, and for this reason the foot should usually be fairly heavy but less heavy than tlie head.

The actual dimensions of both the foot and head will preterablyvary according to service conditions, both being big enough to satisi'actorily meet the intended service without bending inwardly at the bolts when the bolts are tightened but the foot portion should not be heavier than is needed to do this. It is probable that the foot section shown in Figure 3 is smaller than in many cases will be desirable.

In Figure 4 I have moved the web portion of the bars inwardly as compared to the bars shown in Figure 3, and-have also increased the size of the foot 23.

Ihe line 40 between the bearing surfaces at the foot and head respectively here passes I through the web portion of the bar.

The positions of the bar websclose to the rails made possible by the large lateral overhangs of-the head and foot flange ortions at 41 and 42 permit the ready use of olts of shorter length in orderto accommodate the length of the bolt to service conditions.

in Figure 4 ll show upon the bolt a washer member d3 of suficientlength to permit the use of a square nut 44- outside of the outwardly extending flange portions of the bar.

It is usually quite advantageous to use square nuts instead of hex nuts because of the better grip they afiord a wrench.'

It will be seen that the effective length of the bolt is then suflicient to reach from the outside of the web oi? one bar to a point beyond (lid - many cases, may mean a tbhe laterally extending flanges oi the other @bviously the nut member may extend inwardly to any desired degree toward the web of the bar and in Figure 5 I illustrate this, a nut 45 being provided with a reduced por tion 4:6 between the flange portions of the bar and a washer 4c? of any desired length that is seated against the web of the bar. In this illustration the nut member is not threaded throughout its length, one end, shown in the figure as the inner end being given'a sectional interior greater than the threaded portion of the bolt. ihis gives a bolt that is eftectively long and will be desirable when the bolt stock has very low permanent set under service conditions.

lln Figure 6 I member integral.

show the nut and washer The seat in this case should be spherical and only the inner end'portion of the nut need lee threaded. The advantage of the nut, shown in Figure 6, lies in shortening the effective length of the belt, which, bolt not only of the nuts are tightened at a definite value.

It will, of course, be obvious however that reduction in the bolt area and reduction in bolt length will mean a greater stress upon the material of the bolt if the total stretch when the nuts are tightened is to be the same as before.

The form shown in Figure 7 illustrates a nut 48 of sufficient length to afiord ample wrench hold and still avoid the use of a washer.- The'nut may be threaded at any desired portion of its length to obtain any desired effective length of bolt and is illustrated as threaded at the outer end of the nut. The nut is provided with an en larged bore wherever it is not threaded, as toward its inner end. In this figure as in the other figures the nuts'may be square or hex as desired.

When the nut is threaded only at its outer end the effective length of the bolt is relatively great. With some service conditions and bolt characteristics this may be very desirable, for example, when the bolt stock has high elasticity and the tension stress does not exceed a predetermined safe value. A live joint is then obtained by giving the bolt'a sectional area to limit its tension stress during service to the predetermined value. The bolts are made long to increase the uniformityof the clamping force of the bolts upon the splice bars.

Figures 8 and 9 may illustrate a slight modification ofthe form shown in Figure 6 in that the arcuate seat 49 maybe cylindrical instead of spherical and a washer 50 may be inserted between the nut and the web at the bar.

in Figure 8 the inner end 51 of the bore of the nut is threaded whilethe nut is extended at 52 beyond the head and foot lateral flanges a distance sufficient to ailord a wrench hold. In Figure 9 the outer end of the bore of the nut is threaded and the interiorly enlarged inner end is in effect merely an inner extension of the outer nut portion for engagement with the washer. I

it will be seen that I have provided a construction that materially increases the effective life of the splice bars by avoiding a dead engagement between the splice bars and the rail fillets after the bar heads have worn inwardly so as to engage the opposite sides oil the rail web.

l have also provided a novel construction that avoids uneven stresses and strains in the bolts and splice bars during this period.

of increased life-and have also'pointe'd out in what way the relations between the bolt permit an intelligent selection of bolt dimensions according to variant service conditions and variant characteristics of the stock materials, and have disclosed the method of varying dimensional and form characteristics of the bar foot as well as the characteristics of the bolt members to generally improve spirit and scope of my invention.

Having thus described my invention, What I claim as new and desire to secure by Letters Patent is:

1. The method of maintaining a supporting engagement between the under side of a rail head and the head of a splice bar, after the splice bar has engaged the rail web and points outwardly beyond the railfillet, which consists in providing the inner portion of the bar head-with a fulcrum adapted to engage the web of the rail below the fillet after continued service and in drawing the lower portion of the bar inwardly with respectto the bar head so that it bears upon the web to free the fillet, and rides upwardly to engage the rail head beyond the fillet.

2. A splice bar for joining the adjacent ends of railroad track rails havinga head.

initially fitting against the outer portion of the under side of the rail head and fitting against the top of the rail flange at its foot, a fulcrum on the head of the bar adapted to engage the rail web after continued wear between the engaging surfaces of the rail and bar, the bar having a curved contour between the fulcrum and the bearing surface of the head of radius not less than the radius of the rail fillet, and said barhaving also a foot supported upon the rail flange that is relieved upwardly upon each side of its bearing surface at the rail flange.

3. In a rail joint, a splice bar, a head thereof having a fulcrum adapted to engage the rail web after wear has taken place, and a, foot on the lower portion of the bar resting upon the'rail flange and curved upwardly at front and rear for adaptation to inward movement about the fulcrum, after the fulcrum engages the rail web. 4. In a rail 'oint, a splice bar having a head and a foot, a fulcrum on the head adapted to engage the rail web after wear has taken place to limit the inward movement of the ar head without limiting the inward movement of the foot, the said foot being relieved upwardly at each side of its bearing upon the rail 1flange, and a bolt member holding the bar to p ace.

5. In a rail joint, a splice bar having a head and a foot, a fulcrum on the head adapted to engage the rail web after wear has taken place to limit the inward movement of the bar head without limiting the inward movement of the foot, the said foot being relieved upwardly at each side of its bearing upon the rail flange, and a-bolt member holding the I bar to place and having an arcuate socket connection therewith.

6. In a rail joint, a splice bar having a head and a foot, a fulcrum on the head adapted to engage the rail web after wear has taken place to limit the inward movement of the bar head without limiting the inward movement of the foot, the said foot being relieved upwardly at each side of its bearing upon the rail flange, and a bolt member holding the bar to place and having a ball and socket connection therewith.

7 In a rail joint, a rail, a pair of splice bars each havin the web of the splice bar nearer the inner flange extremities than the outer flange extremities of thebar permitting the use of a short bolt, a bolt therethrough and a nut for the bolt extending beyond the outerbar flange extremities for access to the nut.

8. In a rail joint, a rail, a pair of splice bars on opposite sides thereof having the heads of the bars nearer to the rail web than the feet thereof and adapted to swing about theheadsas axes and a bolt passing through the splice bars and having bearing against the splice bars accommodating the tilting of the splice bars.

9. In a rail joint, a rail and apertured splice bars on opposite sides of the rail, the splice bars being grooved horizontally to accommodate the bolts for the splice bars and bolt-heads and nuts or washers being curved in vertical contact planes with the splice bars to accommodate tilting of the splice bars.

EUGENE W. CARUTHERS;

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