US3371866A - Reinforced concrete railway tie - Google Patents

Description

March 1968 R. P. SONNEVILLE REINFORCED CONCRETE RAILWAY TIE 2 Sheets-Sheet 1 Filed July 6, 1965 March 5, 1963 R. P. SONNEVILLE 3, REINFORCED CONCRETE RAILWAY TIE Filed July 6, 1965 2 Sheets-Sheet 2 United States Patent Office 3,371,866 Patented Mar. 5, 1968 3,371,866 REINFORCED CONCRETE RAILWAY TIE Roger Paul Sonneville, Rue Maurice Ravel, Saint-Cloud, Seine-et-Oise, France Filed July 6, 1965, Ser. No. 469,739 Claims priority, application France, Jan. 13, 1965,

1, 3 4 Claims. (Cl. 23858) ABSTRACT OF THE DISCLOSURE The present invention relates to rail supports of railway tracks and more particularly to ties composed of two reinforced concrete blocks, each of which is placed under one of the rails and surrounds a stay consisting of a steel girder.

These ties are known as composite ties owing to the two materials employed, namely, concrete and steel. They already play an important part in the equipment of railway networks. Experience has shown indeed that although no pro-stressing is employed, these composite ties behave very well, even in main line tracks which are subjected to heavy and fast traffic,

However, despite the results already obtained in efforts to reduce the cost price to a minimum by reducing as far as possible the weight of steel and concrete without compromising tie performance, it does not seem that present technical data would lead to a notable reduction in production costs likely to open up new markets for the composite tie.

Presently-known composite ties have indeed the following drawbacks:

(a) The steel stay is relatively expensive. That is to say, the girders having approximately a Y, T, U or I-section are too heavy having regard to their practical functions which are essentially the moment of inertia relative to the horizontal and vertical neutral axis characterising the strength of the interconnection of the two blocks, and the thickness characterising the useful life of the stay subjected to corrosion in track use.

Further, the Y or T-section girders, which have the least number of drawbacks, are diflicult to roll since they require deeply recessed cylinders rotating at low speed.

As concerns I-section girders, although they have a high moment of inertia relative to the horizontal neutral axis, their drawback is that the web is too thin and very vulnerable to corrosion and that they have a very low moment of inertia relative to the vertical neutral axis so that they have a tendency to twist transversely in the course of handling in the yard or in the track.

(b) The moulding of the anchoring devices for the bolts or coach-screws fastening the rails to the concrete blocks of the composite ties includes an excessive number of manual operations. It does not lend itself without extreme complications to track construction by means of automatic laying machines. 7

In particular, presently-known composite ties can be grouped into three types according to the way in which the rails are fastened.

(1) Use of liners of wood, steel (spiral liners) of synthetic plastic material into which the c0ach-screws or bolts are screwed.

This type requires moulding rods which must be fixed to the mould during the pouring of the concrete and then disassembled so as to permit stripping from the mould, which are manual and relatively skilled operations that it is practically impossible to mechanise and above all render automatic.

(2) Use of bolts having a hammer-head fixed in an aperture in the vertical web of the T, Y or I-section girder acting as the stay. The ties described by the applicant in the French Patent No. 984,615, filed on Apr. 1, 1949, are of this type.

The rods which extend through the vertical web of the stay and the mould and lock the stay in the mould in the course of vibration of the concrete up to the moment when the mould is inverted and which are thereafter removed so as to permit the stripping, these rods also providing the hollow space required for the rotation of the fixing bolts, are a serious obstacle to me-chanisation.

Bearing in mind the tolerances employed in the dimensions of the apertures formed in the vertical web of the stay and in the constructional dimensions of the mould, it is hardly possible to position and then extract these pins mechanically and automatically.

(3) The use of bolts extending through an aperture in the horizontal web of a metal U-section stay and anchored in this horizontal web by a rotation of the hammer-headed bolt through in accordance with a method somewhat similar to that employed for fastening rails to metal ties. This arrangement applied to steel and reinforced concrete compositeties has been described by the applicant in the'French Patent No. 1,277,989, filed on Oct. 30, 1961.

But the construction of the cavity or chamber for the rotation and anchoring of the head of the bolt under the horizontal web of the stay requires the use of associated parts, strips provided with bosses, which can be placed in the mould and then removed after stripping only by hand.

Finally, presently-known composite ties have the following further drawback:

The centre of gravity of the current section steel of the stay is located on the same level in the open uncovered part of the stay located on the axis of the track between the blocks as in the covered part inside each of the blocks. This arrangement is illogical.

It can often be desirable that the stay be positioned as high as possible in the centre part of the track so that it can be spaced as far away as possible from the ballast and thus exposed as little as possible to wear and corrosion in contact with this ballast. Provision of ballast in the track which is as thick as possible is indeed considered necessary to ensure maximum track resistance to transverse forces, especially if the track is equipped with long welded rails.

On the other hand, it is usually considered that the centre of gravity of the stay in the part thereof embedded in each of the concrete blocks should be positioned lower down than the centre of gravity of the cross-section of these blocks so as to ensure an improved participation of the resistance of the blocks to the positive bending moments created by the passage of heavy axles.

However, in some special cases, in particular when laying track in a tunnel, on permanent structures or roads, the reverse arrangement might be desired in which the open part of the stay between the blocks is as low as possible.

The object of the present invention is to provide a composite tie which remedies the aforementioned drawbacks. This tie has two reinforced concrete blocks surrounding a stay composed of a steel girder. This stay being an L-section member disposed in the open part between the two concrete blocks so that the plane bisecting the dihedron formed by the two flanges of the L-section member is substantially horizontal.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawings to which the invention is in no way limited.

In the drawings:

FIG. 1 is a perspective view, with a part cut away, of one embodiment of a tie or sleeper according to the invention;

FIG. 2 is a similar view of a second embodiment;

FIGS. 3 and 4 are views, respectively in perspective and in end elevation of the tie shown in FIG. 2;

FIG. 5 is a longitudinal sectional view, taken along line 55 of FIG. 6, of a moulding device for the tie shown in FIG. 2;

FIG. 6 is a cross-sectional view of this device;

FIG. 7 is a cross-sectional view of one of the blocks of the tie shown in FIG. 2, and

FIG. 8 is a partial plan view of this block.

In the embodiment shown in FIG. 1, the tie or sleeper T comprises two reinforced concrete blocks 1 each of which receives on the upper face 2 a rail R. Inserted in these blocks are the two ends of a girder P which acts as a main reinforcement and stay or spacer member for the blocks. According to the invention, this girder is in the form of an angle-iron, namely an L-section member which is so positioned that the plane (represented by the line ZZ in FIG. 1) bisecting the dihedron formed by the two flanges 3 and 4 is substantially horizontal and parallel to the bottom face 5 of each block 1. This arrangement must be achieved, according to invention, at least in the uncovered or open part of the girder P located between the blocks 1. In the embodiment shown in FIG. 1 it is achieved over the entire length of the girder.

For the purpose of fastening the rails R on the face 2 of the blocks, bolts B are shown whose heads are anchored in the blocks 1. Instead of these bolts, it is possible to employ fittings or stirrups which are anchored in or stuck directly to the concrete, or any other fastening means independent of the girder P.

The advantages of employing an L-section member disposed in the aforementioned manner as a stay are as follows:

The angle-iron or L-section member is the cheapest of commercially available section steels and the easiest to construct on an industrial scale even in countries where the steel industry is as yet only slightly developed. Each kilogram of L-section member is therefore cheaper than I-section members and above all special Y or T-section members which are the most commonly employed at the present time.

The L-section member disposed in accordance with the invention has, for a given weight and thickness, a moment of inertia relative to the horizontal neutral axis which is much more advantageous than corresponding T or Y- section members without the moment of inertia in the transverse direction being notably less. For example, a 60 x 60 x 7 mm. L-section member has a moment of inertia relative to the horizontal neutral axis ZZ equal to 41.70 m and weighs 6.23 kg./metre. The current 60 x 60 x 7 mm. T-section member also weighs 6.23 kg./metre but has a moment of inertia relative to the horizontal neutral axis of only 23.8 emf. In both cases the moment of inertia relative to the vertical neutral axis is slightly higher than 10 cmfi. Further, the commercial I-section member of substantially equivalent weight has the dimensions 80 x 42 mm. and a much higher moment of inertia relative to the horizontal axis, namely 77.8 cm.*, but cannot be employed as a stay for a composite tie, as prior experience has shown, owing to an insufficient transverse inertia of only 6.29 cm. and to a web which is much too thin (3.9 mm. as against 7 mm.) and is rapidly destroyed by rust.

It will be observed that the dissymmetry of the L-section member is only apparent if the centre of gravity of the section thereof is placed in the neighbourhood of the longitudinal axis of symmetry of the blocks. Moreover, this dissymmetry can be put to use in double tracks if the apex of the L-section member is oriented toward the direction from which the trains arrive. Danger of trailing objects (coupling hooks of the wagons for example) hooking the L-section member is indeed much reduced while, if the stay must be provided with ballast, the resistance of the L-section member to creep, which usually occurs in the direction of traflic circulation, is considerably increased.

In this way, a good many of the aforementioned drawbacks of known composite ties are avoided. However, in the embodiment shown in FIG. 1, it is not possible to anchor the rail fastening means in the member P, which could be desirable in order to render this fastening more rigid.

The embodiment T shown in FIG. 2 affords this anchoring in an easy and advantageous manner.

The tie T comprises, in the same way as the tie T, two blocks 1 held spaced apart by an L-section member P In its uncovered or open part, the member P is positioned in the same way as the member P. However, in the blocks 1 the flanges 3 and 4 of the member are so disposed that the flange 3 is horizontal at 3a and the flange 4 vertical at 4a. The vertical flange 4a advantageously extends towards the bottom face 5 of the block 1 as shown, but could extend towards the top face 2 if the prevailing conditions render this arrangement preferable. In order to obtain this different arrangement of the flanges of the member T in the uncovered open part and covered end parts, the ends of the member are twisted through roughly 45 about an axis located substantially on the corner edge of the member at the point where these ends enter the blocks 1 (FIGS. 3 and 4).

Tests have shown that this twisting of an L-section member, even of hard rolled steel (the grade of steel suitable for rails), through roughly 45 about the corner or apex of the dihedron is easily achieved, even in the cold state, with a low power press (press exerting a pressure of about 10 tons).

The twisting of the stay shown in FIGS. 24 results in two essential advantages according to the invention, namely:

Owing to this twisting, the centre of gravity of the cross-section of the L-section member P embedded in the blocks 1 is located on a different level from that of the centre of gravity of the cross-section of the member P in the free uncovered part thereof between the two blocks. This is a definite advantage over known devices in which the centre of gravity is of constant height, with the aforementioned corresponding drawbacks. By way of example, is respect of a 70 x 70 x 7 mm., L-section member, the arrangement shown in FIGS. 24 lowers the centre of gravity roughly 20 mm.

The arrangement of the L-section member with horizontal and vertical flanges inside the concrete blocks permits an easy anchoring of the rail fastening bolts B as will be explained hereinafter.

The bolts B have a hammer-head 6 surmounted by a square-shaped locking portion 7. Provided in the concrete of the parts of the blocks in which the bolts have to be inserted are vertical passages 8 (FIGS. 2, 7 and 8) which communicate at one end with the top face 2 of the blocks and at the other end with the horizontal parts 3a of the flange of the member P In the region of the passages 8, rectangular apertures 9 are formed in the parts 3a, the major axis of the apertures being parallel to the longitudinal axis of the tie. In this way, the tie, and above all the member P in the highly stressed region of the rail fasteners, are weakened to the minimum extent.

Located under each aperture 9 is a horizontal passage it! formed in the concrete of the blocks 1. One end of this passage communicates with the vertical part 4a of the flange 4 of the member P and the other end com municates with the longitudinal lateral face of the block 1 opposed to the part 4a relative to the vertical longitudinal plane of symmetry of the block 1. The passage has a substantially rectangular cross-sectional shape and the bottom 12 thereof is slightly curved.

The dimensions of the passages 8 and 10 and of the apertures 9 are such as to permit the insertion and locking of the bolts B under the parts 3a of the member P For this purpose, the passages 8 and apertures 9 have such length and width that they allow the passage of the bolts B with their heads 6 oriented in the direction of the longitudinal axis of the tie. The width of the passages 8 is slightly greater than that of the apertures 9 (FIG. 7), the latter width being substantially equal to one side of the square-shaped portion 7 and to the width of the head 6 of the bolts B As concerns the passages 10, their purpose is to permit rotation of the head 6 of the bolts B through 90 from their position of introduction into the passages 8 and apertures 9. Consequently, they have a height equal to, or greater than, the total height of the head 6 and square-shaped portions 7, when, as in the instant case, such a portion 7 exists. They have a width (FIG. 8) equal to at least the diagonal of the head 6 and consequently the diagonal d of the apertures 9, and their length is equal to at least the distance between the vertical axis of the passages 8 and the face 11 (with which they communicate) plus a distance of d/ 2. Owing to this arrangement, each bolt B can be lowered into the corresponding passage 8 and aperture 9 until the square-shaped portion 7 is located under the flange 3a, turned through 90 and lifted so that the portion 7 engages in the aperture 9. The bolt B is then prevented from rotating While the hammer-head 6 thereof is anchored under the flange 3a and thus affords great strength to the fastening of the rail.

This anchoring of the bolts in the stay P is obtained with the minimum of internal cavities in the tie. Thus, as distinguished from previous composite ties no long horizontal passages extend across the tie from one lateral face to the other, and no vertical passages communicate with the bottom face 5 of the blocks 1 in contact with the ballast. As concerns the latter arrangement, experi ence has shown that it is unreliable for several reasons and in particular because it increases the danger of cracking owing to fatigue of the bottom face which is the most subjected to tensile stress due to bending.

The horizontal passages 10 are short in the presentlydescribed embodiment and their length hardly exceeds half the width of the tie at the level of the stay plus half the diagonal of the head 6 of the bolts 18 They affect the resistance of the blocks 1 to fatigue to a lesser extent as they are located substantially on the level of the horizontal neutral axis of their cross-section.

The tie according to the invention is consequently stronger and has a longer life.

Further, it can be moulded in an extremely simple manner which can be mechanised, as will be seen here inafter from a description with reference to FIGS. 5 and 6, by means of a moulding device and method also covered by the invention.

To carry out this moulding, two half-moulds 13 each of which has the shape of one of the blocks 1 are employed. One of the small lateral sides 114 of each halfmould 13 is notched at 15 so as to clear the L-section member P this notch being closable by a detachable flap (not shown). The member P is positioned in each half-mould 13 by two cores 16 connected to the bottom 17 of the half-mould and adapted to form two vertical passages 8 in each block 1. For this purpose, each core 16 has at its free end a portion 18 of reducedsection having the dimensions of one of the apertures 9 in which it is intended to engage, and the flange 3a rests on the shoulders formed on the core by the portions 18.

t The member P is moreover locked in this position by two pins 19 adapted to form the two horizontal passages 10 in each tie block. Each of the pins 19 is slidably mounted in a sealed manner in a tube 20 which extends outwardly of one of the longitudinal lateral walls 21 of the half-mould 13 and communicates with the interior of the latter by way of an aperture 22 in this wall. When the member P is in position on the cores: 16 it is merely necessary to insert the pins 19 so that they assume the position shown in FIG. 6 to rigidly secure the member P and interconnect by means of the latter the two halfmoulds 13. In this position the ends of the pins 19 abut the flange 4a of the member P and the edges of the pins are applied against the flange 3a in vertical alignment with the cores 16 and close the apertures 9 so as to prevent the concrete from entering therein.

The concrete is then poured into the half-moulds 13 and vibrated. The mould is then inverted, the pins 19 preventing the member P from slipping off the cores 16, and the large base of the tie is laid on the mould stripping surface or plate. Extraction of the pins 19 permits stripping the tie blocks from the half-moulds.

All these operations can be mechanised which much reduces the cost price of the ties. In particular, the short horizontal pins 19 have no need to be introduced into several apertures, the alignment of which is always difficult owing to inevitable manufacturing tolerances in the dimensions of the moulds, the pins and apertures formed in the stays, as is notably the case with certain known ties. Owing to this new arrangement, the pins can be easily inserted and withdrawn by a simple mechanical device such as a small hydraulic or pneumatic jack which merely has to provide the correct guiding of the pins.

This mechanisation is notably rendered possible by the fact that the operations of locking the stay in the mould and moulding the cavities for introducing each hammerheaded bolt into the tie from above and then for rotating the bolt through and anchoring it under the horizontal flange of the stay in accordance with conventional arrangements of metal ties, are eifected by merely two members, namely a core 16 rigid with the bottom of the half-mould and the short guided pin 19 whose movement is easily mechanised.

The tie according to the invention possesses new technical advantages over known composite ties which result in a substantial reduction in the cost price for at least the same performance.

For a given moment of inertia and a given thickness, the L-section steel stay disposed in accordance with the invention is much lighter than previously employed stays.

For a given weight of steel and a given thickness, the L-section stay according to the invention has a moment of inertia with respect to the horizontal neutral axis which is about 50% greater than that of the more common T or Y-section stay. Advantage is taken of this in wide gauge tracks in which a stiffer stay is required to ensure a correct geometry of the track by a strong interconnection of the two blocks.

The L-section stay can be easily twisted through roughly 45 about the corner thereof in the region where it enters each of the blocks in the cold state and on an industrial scale even if the stay has been--as it should have been-rolled from steel having a high elastic limit. This twisting permits vertically offsetting the centre of gravity of the stay between the middle part connecting the blocks and the ends thereof embedded in the concrete blocks. In particular, twisting resulting in a lowering of the centre of gravity of the end portions is of utility in obtaining a greater resistance to the rolling loads transmitted by the rails to the concrete blocks with a minimum of secondary reinforcements. This twisting through 45 of the stay permits obtaining a simple and strong anchoring of the rail fastening bolts, preferably in the horizontal flange of the L-section member which is provided with apertures in the same way as a conventional metal tie.

The manufacture of this new tie by an immediate stripping from the mould is much simpler than in known methods and lends itself admirably to the mechanisation of all the operations including the positioning and extraction of the locking pins serving not only to hold the stay in position when vibrating and inverting the mould, but also to mould the internal cavities which permit the introduction and locking of the rail fastening bolts in one of the flanges of the stay by rotation of the bolts through 90".

The passages and cavities required for manufacturing the tie and anchoring the fastening bolts in the stay, if the tie according to the invention must include such bolts, affect the resistance of the concrete blocks to fatigue much less than known arrangements.

The apertures formed in the horizontal flange of the L-section member weaken the stay much less than the openings formed in a vertical web.

Although specific embodiments of the invention have been described, many modifications and changes may be made therein without departing from the scope of the invention as defined in the appended claims.

Thus, for example, as already mentioned, the flange 4a could extend toward the top face 2 of the tie. In this case,

the two horizontal passages 10 of the same block 1 could communicate with both opposed lateral longitudinal faces instead of the same lateral face of the block.

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

1. Railway tie comprising two spaced blocks of reinforced concrete, a steel stay having two ends embedded in the two blocks, the stay being in the form of an L- section member which consists of two flanges and is so disposed in the space between the two blocks that the plane bisecting the dihedron formed by the two flanges is substantially horizontal, the stay being twisted at substantially 45 substantially about a horizontal axis constituted by the apex of the dihedron in the region of the member where the member enters the two blocks so that the member has inside the blocks one of the flanges thereof substantially horizontal, said horizontal flange having portions provided with rectangular apertures the major axes of which extend in the direction of the length of the member, vertical passages in the block surmounting the apertures and communicating with the top face of the block, cavities in the blocks immediately under and adjoining said portions of the horizontal flange for accommodating the hammer-heads of rail fastening bolts respectively extending through said apertures and permit the locking of the bolts upon a rotation of the bolts through 90, the hammer-heads being inserted in said cavities under said horizontal flange.

2. Railway tie comprising two spaced blocks of reinforced concrete, a steel stay having two ends embedded in the two blocks, each block having two lateral faces extending longitudinally of the tie, the stay being in the form of an L-section member which consists of two flanges and is so disposed in the space between the two blocks that the plane bisecting the dihedron formed by the two flanges is substantially horizontal, the stay being twisted at substantially 45 substantially about a horizontal axis constituted by the apex of the dihedron in the region of the member where the member enters the two blocks so that the member has inside the blocks one of the flanges thereof substantially horizontal, said horizontal flange having portions provided with rectangular apertures the major axes of which extend in the direction of the length of the member, vertical passages in the block surmounting the apertures and communicating with the top face of the block, cavities in the blocks immediately under and adjoining said portions of the horizontal flange for accommodating the hammer-heads of rail fastening bolts respectively extending through said apertures and permit the locking of the bolts upon a rotation of the bolts through the hammer-heads being inserted in said cavities under said horizontal flange, each one of said cavities being constituted by a horizontal passage in the corresponding block communicating with a single one of the longitudinally extending lateral faces of the block and extending transversely into the block from said one of the lateral faces a short distance beyond the apertures to allow rotation of the corresponding hammer-head.

3. Railway tie as claimed in claim 2, wherein the other flange of the L-section member which is substantially vertical inside the corresponding block extends from the substantially horizontal flange toward the bottom face of the block and said horizontal passages extend up to said vertical flange from the longitudinal lateral face of the block disposed on the opposite side of the vertical longitudinal plane of symmetry of the block to said vertical flange.

4. Railway tie as claimed in claim 3, wherein each one of the horizontal passages has a height equal to at least the height of the hammer-head of the fastening bolts plus the height of the square-shaped locking portion surmounting said head, if such a portion is provided, a width substantially equal to at least the diagonal dimension of the apertures in the L-section member and a length substantially equal to at least half the width of each block at the level of the L-section member plus half said diagonal.

References Cited UNITED STATES PATENTS 806,358 12/1905 McGranighan 238- 2,656,115 10/1953 Sonneville 238117 3,039,695 6/1962 Harmsen 238-117 1,683,013 9/1928 Arnold 238-58 ARTHUR L. LA POINT, Primary Examiner.

R. A. BERTSCH, Assistant Examiner.

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