US2296853A - Rail joint - Google Patents

Description

P 1942- Ki 1.. JOHNSON 2 2,296,853

IIIIIII NT Filed April l9, 1941' 5 Sheets-Sheet l l N V E N T 0R CD IGD CD Sept. 29, 1942. K. L. JOHNSON 2,296,853

RAIL JOINT Filed April 19, 1941 3 Sheets-Sheet 2 m N ca l A Q Q Q q t m INVENTOR Md? P 1942- K. JOHNSON 2,296,853

RAIL JOINT 7 Filed A ril 19, 1941 5 Sheets-Sheet s MIOIEJ'Z/ENTOR Va m Patented Sept. 29, 1942 RAIL JOINT Kenneth L. Johnson, Allison Park, Pa., assignol to Hubbard and Company, a corporation of Pennsylvania Application April 19, 1941, Serial No. 389,355

18 Claims.

This invention relates to rail joints.

In present day rail joints in which the abutting end portions of rails are joined together by splice bars, wear of the fishing surfaces, wear of the rail surfaces which contact with the fishing surfaces and stretching of the bolts loosens the joints. Loosening of these joints is progressively accelerated and not only requires constant tightening of the bolts, but is a source of much trouble and expense to railroads.

Present day splice bars used by railroads are designed with tapered top and bottom fishing surfaces so as to permit tightening of the joint by periodic tightening of the bolts to drawn the splice bars into close contact with the rails. In time, however, this wear allows the bars to strike the webs of the rails. When this occurs, the looseness due to wear cannot be remedied by tightening the bolts, and the present practice is to remove and reform the splice bars to fill out or renew their fishing surfaces. Besides wear of the fishing surfaces of the splice bars, wear also takes place in the rails, and some splice bar reforming methods provide for reshaping the bars to conform to the contour of the worn rail nead and flange. While the reforming of splice bars is effective, the time comes when it is necessary to remove and discard the bars and crop off the worn ends of the rails to provide new bearing surfaces.

Beside the labor expense involved in cropping off the rail ends, and the expense of reforming the bars, it is generally necessary to delay and reroute traflic while these repairs are being made. This is not only a troublesome, but at times costly procedure.

In the past, a number of attempts have been made to eliminate wear of the fishing surfaces as well as wear of the rails, by providing renewable fibrous or rubber shims or cushions between the splice bars and the rails, but so far as I am aware, none of these attempts has been successful.

An object of this invention is to produce a rail joint that will not wear and become loosened under the pounding of trafiic.

Another object is to produce a rail joint that does not need constant maintenance.

Another object is to produce a rail joint-that is capable of absorbing shock and vibrations and shims or cushions between the splice bars and rails which will not be forced out of place by the hammering effect of traffic.

These, as well as other objects which will be apparent to those skilled in this particular art, I attain by means of the rail joint construction disclosed in the specification and illustrated in the drawings accompanying and forming part of this application.

Throughout the specification and drawings, similar elements are denoted by like characters.

In the drawings:

Figure 1 is a transversesectional view of a rail joint embodying this invention and is taken on line I--I of Fig. 2;

Fig. 2 is a side view in elevation of the rail joint of Fig, 1;

Fig. 3 is an elevational View looking toward the inner face or rail side of one of the splice bars entering into the make-up of the rail joint of this invention;

Fig. 4 is a perspective View of one of the rubber or rubber-like cushions or shims entering into the make-up of my rail joint;

Figs. 5, 6 and '7 are Views similar to Fig. 3, and illustrate modifications of the inner face or railside of the splice bar of this invention;

Fig. 8 is a diagrammatic view illustrating in an exaggerated manner the action of the downward forces to which the rail joints are subjected in service;

Fig. 9is a perspective view looking toward the rail-side of a splice bar for use in a modified form of rail joint embodying this invention;

Fig. 10 is a perspective View of a metal grid and part of a rubber or rubber-like cushion for use with the splice bar of Fig. 9; and

Figs. 11 and 12 are sectional views taken between the transverse bars of the grid and illustrate modifications in the cushion material.

In Fig, 8, it is assumed that the abutting ends of two rails AA' are joined together by splice bars B. In order to obtain a clear understanding of the principles of this invention, an attempt will be made to analyze the downward forces involved, and the resultant action of the component parts of a joint assembly of the type now in common use.

While the forces due to loading are applied to both splice bars entering into the make-up of the assembly, the diagram of Fig. 8, for the purpose of simplification, deals with the forces as though applied to one such bar only.

When a train passes over a railjoint, the first effect of the wheel load represented by X (Fig. 8) is to depress the entire joint assembly until the supporting ties have a solid bearing in the ballast. When this point is reached the load tends to bend the splice bar, thus causing greater bearing pressures at the point C on its top bearing surface and at the points F and H at the extremities of its lower bearing surface. This bending of the splice bar causes a downward deflection of the rails, which deflection begins at points positioned on opposite sides of the joint assembly and which have been arbitrarily located at Y and Y. From this it can readily be seen that if the splice bar fits snugly between the head and flange of the abutting rails, the load X tends to immediately flex the splice bar without first depressing it. If, however, there is any clearance between its fishing surfaces and the rails, in other words, if the joint assembly is loose, the splice bar as an entirety is depressed to the point where the clearance is closed before the bar is flexed. This is borne out by a study of the Wear in splice bars that have been in service.

In a rail joint that is kept tight, each splice bar has elliptical cavities worn in it adjacent C and G. Similar cavities are also worn in the underside of the head of the rails adjacent C and in the top surface of the rail flange adjacent G. This occurs because of the fact that the load is greatest at these points and there is greater movement between the parts at points C and G during flexing of the bar.

However, in a rail joint that has been in a loosened condition for some time, there will be a greater amount of wear in areas adjacent points C, H and F, showing that the bar as an entirety is depressed until the clearance at points C, H and F is taken up before flexing of the bar occurs. The rail joint of the diagram (Fig. 8) is shown as having clearance between the fishing surfaces of the bar and the bearing surface of the rails, and as under load. The clearances are exaggerated for the purpose of illustration and are represented by the distance between the lines K--K and LL. The top surface of the splice bar has been depressed from KK to M-M.

In its normal position, that is, prior to de-- pression under load, the clearance space between the top fishing surface of the bar and the underside of th head of the rail is represented by the rectangles N, O, P, P and N, O, P, P. If the rails had remained relatively co-axial and paral- V C, but, since the rails flex downwardly about the indeterminate points Y and Y, with their greatest movement at their abutting ends OG, the under surfaces of the rail heads lie along diagonals N, C, and N, C of the rectangles M, N, P, C and P, M, N, C, respectively. In order to set up the foregoing conditions, it must be assumed that all of the above mentioned points and lines, except the points X and Y, are relatively placed and that the entire diagrammed structure moves downward through space, due to force X, a distance equal to the sum of the distance from the top surface of the splice bar to the underside of the rail head, and the distance from the bottom surface of the splice bar to the flange of the rail.

As shown by the diagram of Fig. 8, points J and I are neutral points about which the line KK pivots. This line represents the under surfaces of the rail heads when the joint is depressed. Any points located along the lines JJ or II' are also neutral points. The area of the clearance space becomes greater on one side of one such line JJ or II by the amount that the space on the opposite side thereof becomes less.

Since the indeterminate points Y and Y are spaced at distance outwardly from the ends of the splice bar, and the rail heads lie along the diagonals of the rectangular space bounded by the top of the splice bar and the rail heads prior to depression, the points JJ and II must lie exactly midway between the center of the splice bar and its ends.

As is shown in Fig. 8, the clearance in the region OJ becomes greater by the amount that the clearance in the region JP becomes less, and the clearance in the region IO becomes greater by the amount that the clearance in the region I--P becomes less. This also applies to the clearance spaces between the bottom surface of the splice bar and the top surfaces of the rail flanges, except that the clearance becomes greater in the central region by the same amount that it decreases in the outer regions.

In the rail joint of this invention, the splice bars are of less height vertically than the fishing distance between the under face of the rail heads and the upper face of the rail flanges. That is, the splice bars are so designed that when in use, there is a substantial space between them and the heads, flanges and webs of the abutting rails. Rubber pads, or pads of elastic material having the properties of rubber, are interposed between each splice bar and the rails and are confined in place by the metallic components of the rail joint which are secured together by the rail joint bolts, thus placing said pads or members under compression.

Each splice bar at its top is provided with a longitudinally extending shoulder l6, and at its bottom with a longitudinally extending shoulder l1. These shoulders extend throughout the entire length of the bar and when the bars are in assembled position, the distance from the upper face of shoulder [6 to the lower face of shoulder II is approximately one sixteenth of an inch less than the fishing distance. between the underside of the rail heads and the upper side of the rail flanges.

Each splice bar of Figs. 1 and 3, on its inner or rail-side, is provided with a centrally located longitudinally extending rib l8, transversely extending end ribs I9 and 20 and transversely extending intermediate ribs 2|, 22 and 23. The transverse ribs i9, 20, 2|, 22 and 23 connect at their upper ends with shoulder l6 and at their lower ends with shoulder l I, and with said shoulders and central rib I 8, form eight recesses or cavities which are preferably of substantially uniform depth and are numbered from 24-3I inelusive. Longi-tudi-nally extending rib I8 is provided with holes '32 for receiving the bolts.

Each rubber or rubber-like member or pad is preferably formed as a unitary structure having eight pad-like portions which are numbered 33-40 inclusive and which are connected together by what might :be termed a web which is numbered 4|. The pads are adapted to more or less loosely yet accurately fit recesses or pockets 24-3! inclusive. The pads, when in position, project approximately a? of an inch beyond the outer faces of said ribs and the upper and lower faces of shoulders 16 and II. The web portion 4| overlies intermediate ribs 2 I, 22 and 23 and longitudinal rib 1-8. That portion of the web which overlies rib I8 is provided with holes 42 which register with holes 32 of said rib. Since this web is approximately of an inch in thickness, it assures a clearance of approximately a of an inch between the outer faces of the ribs and the adjacent surfaces of the rails, which clearance is filled with the ruber'or rubber-like web.

As above pointed out, when the splice bars are bolted in place or in assembled position, there is approximately $5 of an inch between the upper face of shoulder l6 and the rail head and between the lower face of shoulder l1 and the rail flange.

Within the range of working pressures due to the loads to which r-ail joints are subjected, the rubber pads can be considered as entirely confined. In a practical sense, this is so, since pressures far greater than any ever encountered would be required to extrude the pad material through the 312 inch slit-like openings at the top, bottom and ends of the rail joint. Aside from this, it would require actual relative movement between the metallic components of the rail joint to extrude the pad material through such slit-like openings, and it can readily be seenthat if this relative movement occurs, the slit-like openings will become smaller or entirely closed.

Entirely confined. rubber is incompressible, in a practical sense, since its coefiicient of compression approximates that of water.

A study of the downward stresses to which a rail joint is subjected reveals the fact that if ribs 2|, 22 and 23 were omitted and. the upper and lower pads extended throughout the area between end ribs I9 and 2|],an entirely diflerent situation would be encountered, when such a rail joint is downwardly stressed, than is encountered in the downward stressing of the rail joint of this invention.

If ribs 2| and 23 were omitted the rubber above longitudinal rib 3 would flow from the central region to the outer region, the lines JJ and II being the boundaries between such regions. The rubber below longitudinal rib l8, forming the bottom bearing area, would flow from the two outer regions to the central region.

This is so because, as was above pointed out, the clearance located between points J and I decreases or closes when the rail joint is depressed while the clearance outward of the points J and I increases. Thus the rubber in the upper bearing area would flow from the inner region to the outer region and the reverse would be true in the case of the rubber forming the bottom lbearing area. Here the clearance in the outer regionoutward of the points J and Icloses, and would force the rubber into the central region.

It can be readily seen that with such rubber pads confined only at the top, bottom and ends, the rail joint would be depressed until the rail touched the splice bars at points H, C and F.

By employing the transverse members or ribs 2|, 22 and 23, with rib 22 placed opposite the abutting ends of the rails, and members or ribs 2| and 23 placed along the lines J-J and II', respectively, as in Fig. 3, the decompressed regions are separated from the compressed regions.

The longitudinally extending member or rib l8 prevents the flow of rubber from region QQ' to region RR and from the outer lower regions H--R and R-F to the outer upper regions M-Q and MQ', respectively. Central transverse member or rib 22 prevents pad material from being forced into any space that may exist between the ends of the rails.

Since each of the rubber pads 34, 35, 31 and 40 is completely enclosed except for said slit-like openings above described, and which are too small to permit any flow of the rubber therethrough, the downward load on the rail joint results in compression only of these rubber cushions, and flow of rubber within the pad as a whole is prevented. Since the rubber is incompressible, it will be readily seen that depression of the rail joint is impossible prior to flexure of the splice ibar. Loadings on the joint, no matter how great, cannot harm the rubber pads. Such loadings will be transmitted through the pads to the spice bars. The splice bars are thus immediately flexed without metal to metal contact and resulting wear in the component parts of the joint.

At the present time, in order to suit particular conditions of road bed, ballast, etc., some rail joints are designed to use splice bars having a vertical camber of as much as .040" while others are designed to have a vertical camber of as little as .015. Such cambers are provided so that the bars under load will be straight.

In rail joints of this invention in order to meet conditions where a vertical camber is desired, it will be found advisable to allow more flexibility than can be obtained by the structure just de-' scribed in which transverse members or ribs 2| and 23 are located along the lines J-J and II'.

If the rubber pads are confined to the extent of preventing all internal flow of the rubber, interfacial movement between the pads and the rail surfaces will take place when relative movement of the metal parts of the joint incident to fiexure of such cambered bars occurs. This will cause wearing of the pads.

The necessary flexibility to take care of such conditions can readily be obtained by varying the positions of members or ribs 2| and 23 It will be apparent that if the top portions of members or ribs 2| and 23, that is, the portions above longitudinal member or ribs l8, are moved outwardly of lines JJ' and II', (Fig. 6), some of the decompression zone pads will be added to the compression zone pads. Thus pads 34 and 35 are increased in length while pads 33 and 36 are decreased in length. This makes: possible some internal flow of rubber within pads. 34 and 35 resulting in increased resiliency.

Likewise, if the lower parts of members or' ribs 2| and 23, that is the parts below longitudinal member or rib I8, are moved inwardlyof lines J--J and 1-1 (Fig. 6) pads 31 and 40' are increased in length while pads 38 and 39; are decreased. This adds rubber from the de-- compression zones and takes away rubber from. thus obtaining more:

the compression zones, resiliency.

Another modified form of splice bar embodyingthis invention and which is comparable to that. In this; modification, the members or ribs 2| and 23 are:

shown in Fig. 6 is illustrated in Fig. 5.

bars of Figs. 5 and 6 is that it is somewhat easier to produce.

Since the railroads require forged or rolled steel splice bars, it is necessary in order to produce commercially the splice bars of Figs. 1, 3,. 5, 6, and 7 to die roll the same. This is not 7 sides of the grid bars.

only diff cult, but more or less expensive, because of the initial cost of the matrix rolls and the cost of their up-keep.

Figs. 9 to 12 inclusive disclose a modification of this invention in which a simple form of splice bar can be utilized in the make-up of the rail joint.

The splice bar (Fig. 9) is provided with an upper shoulder l6 and a lower shoulder 11. These shoulders, when the splice bars are in place, are designed to leave a clearance of approximately es of .an inch between their upper and lower surfaces and rail heads and flanges respectively, as in the splice bars previously described having the pad recesses in their rail sides. The rail-side of the splice bar of Fig. 9 between shoulders l6 and I? is contoured to conform to the contour of the rails,

Pads of rubber or rubber-like material are positioned between the splice bars and the rails as set forth in connection with the rail joint of Figs. 1 to 7 inclusive. The ei ht pads are separated by the members or bars of a metal grid such as illustrated in Fig. 10.

Each of these grids is provided with a longitudinally extending central member or bar l8a, end members or bars l9a and 20]. a transverse center member or bar 22 and transverse members or bars 2m and 230, which are located between the end members or bars and member or bar 220.. These grids are preferably punched from sheet steel approximately thick and are bent to conform to the rail-side of the splice bars and the rail faces between shoulders I6 and I! of the splice bar.

The spaces between the members or bars contain the pads of rubber or rubber-like material such as shown at 36a. and 40a. Pads 35a and 39a are shown partially cut away for the purpose of illustration. The pads are joined by a weblike portion 4 la which overlies the rail-side faces of central member or bar l8a and the rail-side faces of the transverse members or bars lSa to 23a inclusive.

Fig. 11 is a transverse section taken through a modified form of grid and cushion between two of the transverse members or bars and shows the web Ma overlying the members or bars of the grid on the splice bar side thereof instead of on the rail-side as in Fig. 10. Fig 12 is a transverse section similar to the section of Fig. 11, but in this modification, webs 4 la overlie both In other words, in this form, the grid is completely covered by pad material.

The rubber or rubber-like pads are preferably molded onto the grids so that each grid and its pads becomes an integral structure and can be handled as a unit.

While the pads of Fig. 10 are shown as about one half the size of the pad portions of Fig. 4, it will be apparent that the width of the pads is dependent upon the width of the transverse members or bars and that it is only necessary to have the transverse members or bars strong enough to hold the pads in position when the rail joint is under load.

For the purpose of conserving rubber and'for this purpose only, the pads and the transverse bars in Fig. 10 are shown of the same width.

The transverse members or bars of the grid may be of the same width as the transverse ribs of the splice members or bars of Figs. 3, 5, 6, and '7, if desired, thus making the pads of the same width as the pads of Fig. 4.

If it is desired to form the splice bars without shoulders l6 and I1, the grids may be formed with top and bottom bars which join the transverse bars and which then will take the place of shoulders l8 and I1. If such a construction is adopted, the rubber or rubber-like web material may extend to the outer edge of the top and bottom members or bars of the grid or it may terminate at the inner edge of such members or bars. I

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

1. In a railroad rail joint, splice bars located on opposite sides of the rails, and each having a central portion which parallels the rail webs, and top and bottom portions which extend outwardly below the rail heads and above the rail flanges; the rail-side of each bar being provided with eight recesses four of which extend from an area adjacent its longitudinal center into the top portion of the bar, and four from said area into the bottom portion of the bar, rubber-like pads located within said recesses and extending outwardly therefrom beyond the recess walls, thus spacing the splice bars from the rails, and bolts for securing together the component parts of the rail joint.

2. In a railroad rail joint, metal grids located between the rails and splice bars and each having a central longitudinal bar, transverse bars which extend above and below said central bar, rubber pads located within the spaces between said transverse bars and extending outwardly therefrom beyond the same, and means for securing together the components partsof the rail joint.

3. In a railroad rail joint, splice bars located on opposite sides of the rails and each, on its rail side above and below its longitudinal center having recesses which extend into its top and bottom portions, pads of elastic material located within and extending outwardly from said recesses, and means securing together the component parts of said rail joint with said pads in contact with the web, flange and head portions of the rails.

4. In a railroad rail joint, splice bars located on opposite sides of the rails, metal grids between the splice bars and the rails and each having a longitudinally extending central bar and a series of transverse bars; said splice bars having shoulders extending along their upper and lower longitudinal edges and which, with said grids form a series of upper and. a series'of lower recesses, rubber-like pads located within and extending outwardly from said recesses beyond said grids and said shoulders, and means securing together the component parts of the joint with said pads in contact with the web, flange and head portions of the rails.

5. In a railroad rail joint, splice bars located on opposite sides of the rails, metal grids located between the splice bars and the rails and each having a longitudinally extending central bar and a series of four transverse bars; said splice bars having shoulders extending along their upper and lower longitudinal edges, and with said grids forming a series of. upper and a series of lower recesses, pads of elasticv material located within and extending outwardly from said recesses beyond said gridsand said shoulders, and meanssecuring together the component parts of the jointwith said pads in contact with the web, flange and, head portionsof the rails.

6. Means for securingtogether the adjacent ends of railroad rails, and which includes splice bars located on opposite sides of the rails, grids located between the splice bars and the rails and each having a central longitudinally extending bar, transverse bars at its ends and center, and bars between its transverse end and center bars, pads of elastic material located within the spaces between said grid bars and which extend outwardly therefrom, and means for securing the splice bars in place.

'7. A splice bar having shoulders extending along its longitudinal edges and having its rail side provided with a central longitudinally extending rib, transversely extending ribs at its ends and center and transversely extending ribs intermediate said center and end ribs and which with said shoulders form pad recesses.

8. A rubber-like cushion member for use in the make-up of a railroad rail joint and which comprises a plurality of rows of pads connected together by rubber-like material which is flush with one face of said pads and is of materially less thickness than said pads.

9. A device for use between a splice bar and the end, portions of adjacent railroad rails, and comprising a metal grid substantially co -extensive in length with the splice bar, conforming to the rail-side of the splice bar and having a central longitudinally extending bar, transverse bars at its ends and center, and bars between its transverse end and center bars, and pads of elastic material located within the spaces between said bars and which extend outwardly therefrom on at least one side thereof.

10. In a railroad rail joint, pads of cushion material located on opposite sides of the rails and contacting with the rail webs, heads and flanges, and means including splice bars and grids for confining said pads and holding the same in place.

11. In a railroad rail joint, pads of cushion material located on opposite sides of the abutting ends of the rails and contacting with the rail heads and opposite sides of that portion of the rail webs above the rail bolt holes, pads of cushion material located on opposite sides of the abutting ends of the rails and contacting with the rail flanges and that portion of the rail webs below said bolt holes, splice bars having recesses within their rail-side portions within which said pads are located, and means for securing together the component parts of the rail joint.

12. In a rail joint for connecting the ends of track rails, juxtaposed rows of pads of material having the properties of rubber arranged in spaced relation on opposite sides of the rails, extending longitudinally of the rails above their longitudinal center line and contacting with the webs and the under surfaces of the rail heads, juxtaposed rows of similar pads arranged on opposite sides of the rails below said center line and contacting with the webs and the upper surfaces of the rail flanges, rigid members which surround said pads and are spaced from the rails by said pads, and means for securing together the component parts of the rail joint; the construction and arrangement being such that said rigid members hold said pads in place during Vertical loading of the rail joint and prevent flow of pad material from compression to decompression areas of said joint.

13. In a rail joint for connecting the ends of track rails, a row of at least four pads of elastic material having the properties of rubber arranged in spaced relation longitudinally of the rails and positioned between the splice bars and the rails above the longitudinal center line of the rails and contacting with the webs and the under surfaces of the rail heads, another row of at least four similar pads arranged in spaced relation below said center line and contacting with the webs and the upper surface of the rail flanges, rigid members which surround said pads and hold the same in spaced relation, and bolts for securing together the component parts of the rail joint; the space between the rigid members and the adjacent surfaces of the rails being such that extrusion of pad material through such space, because of pressures exerted on the pads during vertical loading of the rail joint, is prevented.

14. In a rail joint for connecting the ends of track rails, a row of at least four pads of elastic material having the properties of rubber arranged in substantially equally spaced relation longitudinally of the rails and positioned between the splice bars and the rails and contacting with the under surface of the rail heads, another row of at least four similar pads arranged in substantially equally spaced relation and contacting with the upper surfaces of the rail flanges, rigid members which surround said pads and hold the same in spaced relation, and bolts for securing together thecomponent parts of the rail joint; the construction and arrangement being such that said rigid members, during vertical loading of the rail joint, prevent flow of pad material from compression to decompression areas of said joint.

15. A structure according to claim 12 in which the pads of each row are connected together by a web of less thickness than the pads.

16. A structure according to claim 12 in which the pads are equally distributed on opposite sides of the abutting ends of the rails.

17. A structure according to claim 12 in which there are three rigid members on each side of the rails which extend longitudinally of the rails, one along the tops of the pads positioned above he longitudinal center line of the rails, one along the bottoms of the pads positioned below said longitudinal center line, and one between the pads of the top and bottom rows, and three rigid members which extend between the adjacent ends of the pads in each of said rows, and two which lie at the outer ends of the end pads of each of said rows.

18. A structure according to claim 13 in which one of the rigid members on each side of the rails extends along the top of the splice bar, one along the bottom of the splice bar, one between the pads of the top and bottom rows, three between the adjacent ends of the pads in each of said rows, and two which lie at the outer ends of the end pads of each of said rows.

KENNETH L. JOHNSON.

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