US3190558A - Rail joint bar - Google Patents

Description

J 1965 w. E. GRIFFITHS RAIL JOINT BAR 3 Sheets-Sheet 1 Filed Nov. 16. 1962 June 22, 1965 w GRIFFlTHs 3,190,558

RAIL JOINT BAR Filed Nov. 16, 1962 3 Sheets-Sheet 2 IN VENTOR 710.41 MW E. GP/FF/THS June 22,, 1965 w. E. GRIFFITHS ,5

RAIL JOINT BAR Filed Nov. 16, 1962 3 Sheets-Sheet 3 NORMA T/HEAD 0F BAR OUT AND BASE IN STRESS ON BOLT REMAINS i CE CENTERED ON BOLT AXIS REGARDLESS OFANGULAR POSITION OFJOINT :SAR.

F ICE. 8. DIAGRAM SHOWING HOW THE PRESENT INVENTION MAINTAINS STRESS 0N BOLTS AT THEIR CENTER LINES INITIALPOSITION '1AFTIER VERTICAL STRETCHING,FACE BEFORE BOLTING 1 PRESSURE I or AR PULLS AWAY ABOVE HEAD OF BOLT a:

L I L AND THROWS STRAIN ON *LOWER EDGE or BOLT HEAD F I G 9 DIAGRAM OF WHAT WOULD HAPPEN INCLARK AND FARIES BARS WHICH ARE DESCRIBED A5 BEING STRETC HED VERTICALLY 1N VEN TOR W/u, mm 6, .GE/FF/Hf-S United States Patent 3,f%,553 RAlfL JIQHNT EAR Wiiiiam E. Griffiths, 1477 Bayview Ave, Toronto 17, fivntario, Canada Filed Nov. 16, 1%2, Ser. No. 238,839 4 Cfaims. (6i. 238-243) This application is a continuation-in-part of my prior application Serial No. 642,601 filed February 26, 1957.

The invention is directed to an improvement in rail joint bars of the head free type rolled from high carbon steel and relates more particularly to a special feature incorporated in the outer bolting face of the joint bar to obtain improved bearing between the bolt head, nut, or washer and the face of the joint bar; reduce stress in the joint bolt to enable it to maintain its full clamping effect within its elastic limit, and to compel correct bar seating conditions. Joint bars are in the nature of beams or girders including a web and top and bottom chords which are inherently stiff or rigid in the sense that they do not appreciably bend or yield under the forces or loading conditions imposed thereon. That is to say, the stiffness of the joint (combination of rail and joint bars) should not be greatly different from that of the rail itself, and there should be freedom from play in the joint in the application of forces acting upon it.

Even bolt tension, that is, the same tension on all bolts of the joint, is considered of paramount importance, and bolting machines have been made and used to give this tension automatically so that the web of the bar gives the same resistance at all bolt locations which could not possibly be true of a resilient bar that changes its shape under pressure.

Rail joint bars as used in the past and present have a fiat outer surface between the top and bottom flanges of the bar. By faulty design, or aggravated mill tolerances in both the rail and joint bars, or also because of wear in the fishing surfaces of both the rail and the joint bars, this fiat outer bolting surface may take a number of undesirable tilted positions relative to a plane perpendicular to the axis of the joint bolts which causes nuts or the heads of bolts to seek a canted bearing which is not at right angles to the axis of the shank of the bolt with consequent damaging effects on the bolts and bars.

For example, when the vertical flat face of the bar is tilted inwardly toward the head of the rail, the lower edge of the bolt head takes all of the bearing pressure. On the other hand, when the flat vertical outer face of the bar tilts outwardly, the upper edge of the bolt head takes all of the bearing pressure. In either of these positions the combined stresses in the bolt shank build up in excess of the normal elastic limit of the bolt and, therefore, the bolt is strained permanently and loses tension which is essential to keeping the bars in proper position in the fishing areas of the rail ends. This condition causes aggravated Wear and the joint bars to become loose, and the joint assembly is then of reduced efficiency at the essential contact points of the joint bar and rail.

Accordingly, one of the objects of the invention is to provide a vertically and longitudinally rigid joint bar having an outer face whose nut and bolt head seating areas at the zone of the center line of the bolt holes presents an outwardly offset horizontal longitudinally disposed limited area of bearing for the said bolt heads or nuts. This bearing is located outwardly beyond all other parts of the outer face of the bar so that when the bolts are tightened the contact between the bolt head and joint bar is closer to the center line of the bolt shank, and the upper and lower outer edges of the underside of the bolt head or nut do not contact the outer surface of the bar, thereby reducing the combined stresses tending to 3,l%,558 Patented June 22, 1965 strain the bolt beyond its elastic limit. Also by preventing the contact of the bolt head from shifting to either the upper or lower edges of the bolt head or nut with the lightest variation in the positions of the bar face, it will maintain a more even distribution of the pressures at all points of contact between the joint bar and rail.

Another object is to provide a bearing on the outer face of the bars by which the same will be compelled to seat properly in the head fillets and on the base flanges of the bar. This is particularly important because with the advent of larger radius fillets at the head of the rail the bolt pressure must be applied in such a way as to keep the pull of the bolt on the center line at all times to eliminate the chance of such pressure being applied either above or below said center line as often now occurs, because, the tolerances, due to whatever cause, in both the rail and the bars create a tendency to cock the bar which makes the outer flat face inclined or tilted inwardly or outwardly.

A further object of the invention is to provide various formations in the outer face of the bar to assure a limited horizontally disposed contact with the heads or nuts of the bolts. For example, the outer face may be wholly or partly a segment of a circular curve with the centre of curvature on or near the longitudinal centre line of the joint bolt, the radius of the curve to be of such length as will give the required curvature, or, the outer face may be wholly or partly a compound curve, it being understood for purposes of this description that compound curves and so-called spiral or evolutionary curves are the same thing. The curvature provided for the bar face is so designed and situated that the plane of the underside of the bolt head, nut, or washer will, where it contacts the bar, be tangent to the curved surface of the bar along a line which will generally pass through or adjacent to the longitudinal centre line of the joint bolts, and will not pass through the upper or lower limits or edges of the bolt head, nut, or washer. Other formations will also serve the purpose, as will later appear, but in all cases such formations will cause the head and foot portions of the bar to adjust themselves under bolt pressure to the mating rail surface without cocking so that they will be most advantageously seated.

Preferred and practical embodiments of the invention are shown in the accompanying drawings, in which:

FIG. 1 is a diagrammatic view illustrating a rail in half section and a joint bar with a uniformly curved outer face according to one proposal of the invention.

FIG. 2 is a view similar to FIG. 1 showing the outer face joint bar having a compound curve.

FIGS. 3, 4 and 5 are detail isometric projection type views illustrating ditferent forms of outer faces for the bars, each presenting substantially a horizontal line contact for either the head of the bolt or the nut.

1G. 6 is a reproduction of a photoelectric study of a bar having a curved outer face with the load applied at the center line of the bolts, as per FIG. 1.

FIG. 7 is a reproduction of a photoelastic study of a bar having a compound curved outer face with the load applied at the center line of the bolts, as per FIG. 2.

FIG. 8 is a diagrammatic illustration of how the invention in this case performs throughout the life of the bar.

FIG. 9 is a diagrammatic illustration of prior art patents which do not achieve the objects of the present invention.

Similar reference numerals designate corresponding parts throughout the several figures of the drawing.

Before proceeding to the description of the present invention, the prior art may be advantageously reviewed. For example, the patents to Clark, 1,831,227 dated No- J vember 10, 1931, and Faries, 1,843,448 dated February 2, 1932, and diagrammatically illustrated in FIG. 9, show joint bars with curved outer and inner faces because the bars are bowed outwardly between the head and foot for the express purpose of vertically stretching the web. To follow this impractical teaching would cause the bars to expand upwardly and downwardly so that the head or foot of the bars tend to separate the head and base of the rail under the pressure of the joint bolts.

Dealing first with the patent to Clark, the cross section FIGURES 6 to 19 show the bar only at either its end or centre positions. Referring to FIGURES 1, 2, 3, and 4, it can be seen that Clark has eliminated the fishing contact over the major portion of the bar, both the top and bottom, and there are no cross sections to show how much of the bar has been removed or to what extent the bar has been weakened in these areas. Certainly, it gives no support to the rail in these areas. Further, the bolts are all located within the weakened area and their principal effect would be, especially as the section is further weakened by the bolt holes, to bend the bar in towards the Web of the rail, thereby rotating the end portions of the bar out from the rail and destroying the fishing contact there. The same effect would carry to a lesser degree at the centre. Apart from their structural weakness, these bars would be diflicult, if not impossible, to roll and would have to be either forged or machined.

The Faries patent is based wholly on a bar being made of highly resilient material which will permit it to conform to any shape of rail surface with which it comes in contact, and also, when it makes contact at both the top and bottom with the related parts of the rail, the patentee says the bar will stretch vertically as illustrated in FIGS. 1, 2, 3, and 4 of the patent drawings. If there is any rotation of the bar, then because of the planar surfaces of contact at the load bearing areas of the fishing, particularly under the head of the rail, this area of contact will be practically eliminated by the slightest rotation. The Faries specification says (page 1, line a further purpose is to accommodate difference in contours of adjacent rail ends of a joint by high resilience in the point bars. This is again repeated and extended on page 1, lines 3843 of the text of the patent. If a joint bar is so flexible or plastic that it will fit any variation in size or shape of rail surface, it is impractical because under pressure, the bar will accommodate itself to any rail contour. Then, for the same reason, the bolt pressure will also distort the bar at the points where the bolt heads or nuts contact with the bar, and therefore it would be impossible to say what would be the position of that portion of the bar on which the bolt or nut took a hearing.

A joint bar for practical purposes is, as previously stated, a rigid beam which is short as compared with the length of the rail, and which must be maintained in a suitable position relative to the rail in order to perform its function of properly supporting the rail ends. It is held in this position by bolts. A joint bar is not a flexible or plastic member that can be forced under bolt pressure to change its pre-calculated shape in order to fit the rails it connects and supports, and therefore does not expand.

Considering now the amount which a bolt shank must stretch within allowable elastic limits when tightened to hold the joint bar properly in place as distinguished from a joint bar which will stretch if the bolt shank is subjected to a stress of 25,000 pounds per square inch, then the deformation or stretch in the bolt between the nut and the head, a distance of about four inches, will be of the order of ths of an inch. If now the joint bars, and there are two of them, yield under bolt pressure by so much as 2,000ths of an inch each, then the total of this give of both bars is A ths of an inch, and the bolt while within its elastic limits loses its tension and cannot support the joint bars. If the bolts are then tightened further to regain bolt tension, the bars will only stretch further, and therefore, with a joint bar of sufiicient flexibility to stretch vertically, it would become practically impossible to obtain the necessary tension in the bolts to provide the required pressure on the bars.

Therefore, for all practical purposes, it is correct to say that the joint bar is substantially rigid vertically, and for the same reason, it is incorrect and impractical to say the bar having the structural limitations as described herein will also stretch vertically under bolt pressure.

Briefly, in a joint bar assembly the rail and joint bars are sufficiently strong and are essentially rigid so that when the bolts are tightened they can, under tension and within their elastic limits, develop sulficient force or pressure to hold the rail and the joint bars together so that the assembly will function properly and will support the wheel loads on the rail.

The foregoing is definitely contrary to the statements which have been made in the Clark and Faries patents that a joint bar can, under stress, be made to stretch, deform, or change its predetermined shape, in order to accommodate itself to tolerances or varying conditions of wear.

As shown in FIGS. 1-7 of the present case, the rail R is provided with the usual head 1 and base 2, the former having the fillet 3 in which the head 4 of the headfree joint bar B is intended to fit. The foot portion 5 of the bar engages the base 2 of the rail in the area 6.

The joint bar B has a web portion 7 provided with one or more bolt holes 8 each having the axis or center line C-L which customarily coincides with the center line or axis of the bolts. The web portion generally may be of any desired cross sectional profile but the outer face 9 and inner face 9d of said web are of special construction at least along the area bounded by the bolt holes to perform the functions and the advantages of the present invention.

As Will be seen from FIG. 1 of the drawing, the outer face 9 is formed as a simple curve whose zenith 10 is located substantially at the center line of the bolt holes and bolts C Whose shanks 11 are provided at one end with a conventional head 12 (FIG. 2) and at the other end with the usual lock washer and nut 13 and 14 respectively (FIG. 1).

Thus, as will be seen from FIGS. 1 and 2, the inner face of the bolt head or nut will bear only on the zenith or crown 10 of the outer face of the bar, which outwardly offset portion as a practical matter, extends throughout the length of the said outer face to provide a continuous bearing crest. In that way, the bolt or nut will have only a limited horizontal linear bearing contact substantially in the form of a line or relatively narrow strip disposed lengthwise of the bar and in the plane of the center line or axes of the bolt holes. The invention would be the same, however, if the crested offsets were separate and located at each bolt hole as shown in the modification of FIGURE 5.

When the bar B is put in position relative to the rail R, and the bolts C are tightened, the line of force or pull will be along the line C-L, and, if the bar is not correctly seated, the preliminary pull on the bolts will cause the bar heads engaging the rail head fillets to move sufliciently on the fishing surfaces of the rail to adjust themselves in proper seating relation in said head fillets 3 and on the bottom flange of the rail base 2.

As more clearly illustrated in FIGURES 1 and 2, the inner face 9d of the bar web 7 is formed with a vertically disposed planar surface extending at least the vertical height of the limits of the bolt holes 8. This construction further precludes the vertical elongation of the bar B upon application of tension by the bolts 11.

There will be no chance of the inner side of the bolt head or nut to contact the bar face of either side of the limited contact zone above referred to, that is, above or below the outwardly projecting horizontal contact area 10 so that no undue eccentric stress is placed on the bolt which will impair its elastic limit. In this way the tightness of the bolts is insured for a substantially greater period of time than heretofore known and the relationship of the bolt and bars is automatically obtained correctly regardless of the manner in which the bars and bolts are assembled to the rail.

FIG. 3 illustrates a modified form of bar B wherein the outer face 9a is provided with a central crowning rib providing a limited contact 10a. This rib is located at the line of the bolt holes.

FIG. 4 illustrates a further modification wherein the bar B- has its outer face of pyramidal form provided by a pair of outwardly projecting planar surfaces so that the limited contact 18b is in the plane of the center line of the bolt holes 8b.

FIG. 5 illustrates a modification wherein the bar B has its outer face provided with upper and lower surfaces 90 which terminate in a relatively small half-round bead 19c whose outer surface is curved and the zenith of the curve provides a bearing in the plane of the axis of the bolt holes.

In all forms of the invention it is intended to provide a horizontal contact substantially in the form of a line as compared with the relatively wide area of the usual outer face of the bar, so that the underside of the head of the bolt, nut or a lock-nut where one is used will bear only on a limited area which constitutes the focal point of bolt tightening pressure and performs the dual function of compelling the bars to seat properly in the fishing space of the rail while avoiding overstressing of the bolts so that they will not stretch and relax their grip on the bars.

The bearing must be in the zone of the center line of the bolt holes and project outwardly of adjacent upper and lower portions of the outer face of the bar so that when the bolt head or nut is in contact with said bearing it will never engage the face of the bar at any other point while the bar moves in the distance X which is in the range of to The distance X will be the maximum over which the bar can rotate to meet the greatest allowable fullness in both the bar and the rail, as well as the maximum wear in both before the bar is considered Worn out.

Reference to the photoelastic studies in FIGS. 6 and 7 will bear out the advantages above mentioned. For example, FIG. 6 shows a pair of joint bars B having duplicate curved outer faces on the order of 9 in FIG. 1. Pressure, simulating bolt pressure, is applied to the bars at the point 10 and an exceptionally favorable stress pattern results showing that the head and foot portions of the bar are properly seated and the uniform stress is imposed at the line of the bolt holes.

The above comment also applies to FIG. 7 wherein the outer face 10 is in the form of a compound curve instead of a simple continuous curve as in FIG. 6. In this case the outer face of the bar is formed by two arcs whose zenith intersects at the line of the bolt.

FIGURE 8 shows applicants objective.

A comparison of the foregoing features with what would take place in cases where bars have outer as well as inner curved faces as in FIG. 9 to make the bar elongate vertically, shows that the present invention is a decided advance forward in the art.

I claim:

1. In a rail joint for connecting rail ends each having fixed fishing areas defined by webs, and head and base flanges,

vertically rigid rolled rail joint bars having pre-determined physical dimensions compatible with and engaging the bearing portions of said rail fishing areas, said bars including a web portion provided with longitudinally aligned bolt holes, said web having an inner face including a vertical planar surface extending at least the height of said bolt holes,

means for maintaining the rigid joint bars in effective clamping relationship to the related surfaces of the rails throughout the useful life of said joint bars, by causing clockwise or counter-clockwise rotation of the bars relative to the said bolt holes due to wear at the head and foot thereof,

said means comprising horizontal non-planar outer bolting face portions projecting outwardly from the outer faces of the webs at the location of the center lines of the bolt holes to provide a longitudinal horizontal bearing for transversely engaging the inner faces of the bolts and nuts to provide a limited linear bearing area concentrating the force of the axial pull on the bolts, only in the direction of and parallel to the axes of the bolts while avoiding concentration of bolt pressure above and below said horizontal bearing automatically to cause rotatable clockwise or counterclockwise rotation of the bars in the rail end fishing to compensate for Wear and maintain uniform clamping forces solely in the direction of the axes of the bolts.

2. A rail joint bar according to claim 1, wherein, said linear bearing area is provided by a half-round rib disposed between a pair of fiat surfaces.

3. A rail joint bar according to claim 1, wherein, said outer bolting face portion includes a pair of angularly disposed portions converging to a peak intersected by the center-line of the bolt holes to provide said linear bearing area.

4. A rail joint bar according to claim 1, wherein, the outer face of the bar includes angularly disposed portions connected by a half-round rib whose zenith is disposed at the center-line of the bolt holes.

References tilted by the Examiner UNITED STATES PATENTS 1,126,289 1/15 Rundgren 238-253 X 1,213,699 1/ 17 Sims 238-253 1,768,391 6/30 Wolhaupter et a1. 238-243 1,831,227 11/31 Clark 238-243 1,843,448 2/32 Faries 238-243 EUGENE G. BOTZ, Primary Examiner.

LEO QUACKENBUSH, ARTHUR L. LA POINT,

Examiners.

Claims (1)

1. IN A RAIL JOINT FOR CONNECTING RAIL ENDS EACH HAVING FIXED FISHING AREAS DEFINED BY WEBS, AND HEAD AND BASE FLANGES, VERTICALLY RIGID ROLLED RAIL JOINT BARS HAVING PRE-DETERMINED PHYSICAL DIMENSIONS COMPATIBLE WITH AND ENGAGING THE BEARING PORTIONS OF SAID RAIL FISHING AREAS, SAID BARS INCLUDING A WEB PORTION PROVIDED WITH LONGITUDINALLY ALIGNED BOLT HOLES, SAID WEB HAVING AN INNER FACE INCLUDING A VERTICAL PLANAR SURFACE EXTENDING AT LEAST THE HEIGHT OF AID BOLT HOLES, MEANS FOR MAINTAINING THE RIGID JOINT BARS IN EFFECTIVE CLAMPING RELATIONSHIP TO THE RELATED SURFACES OF THE RAILS THROUGHOUT THE USEFUL LIFE OF SAID JOINT BARS, BY CAUSING CLOCKWISE OR COUNTER-CLOCKWISE ROTATION OF THE BARS RELATIVE TO THE SAID BOLT HOLES DUE TO WEAR AT THE HEAD AND FOOT THEREOF, SAID MEANS COMPRISING HORIZONTAL NON-PLANAR OUTER BOLTING FACE PORTIONS PROJECTING OUTWARDLY FROM THE OUTER FACES OF THE WEBS AT THE LOCATION OF THE CENTER LINES OF THE BOLT HOLES TO PROVIDE A LONGITUDINAL HORIZONTAL BEARING FOR TRANSVERSELY ENGAGING THE INNER FACES OF THE BOLTS AND NUTS TO PROVIDE A LIMITED LINEAR BEARING AREA CONCENTRATING THE FORCE OF THE AXIAL PULL ON THE BOLTS, ONLY IN THE DIRECTION OF AND PARALLEL TO THE AXES OF THE BOLTS WHILE AVOIDING CONCENTRATION OF BOLT PRESSURE ABOVE AND BELOW SAID HORIZONTAL BEARING AUTOMATICALLY TO CAUSE ROTATABLE CLOCKWISDE OR COUNTERCLOCKWISE ROTATION OF THE BARS IN THE RAIL END FISHING TO COMPENSATE FOR WEAR AND MAINTAIN UNIFORM CLAMPING FORCES SOLELY IN THE DIRECTION OF THE AXES OF THE BOLTS.

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