US3888414A

US3888414A - Resiliently yieldable rail fastening

Info

Publication number: US3888414A
Application number: US466919A
Authority: US
Inventors: Michel Duchemin
Original assignee: Ressorts du Nord SA
Current assignee: Ressorts du Nord SA
Priority date: 1973-05-03
Filing date: 1974-05-03
Publication date: 1975-06-10
Anticipated expiration: 1992-06-10
Also published as: GB1471023A; BR7403621D0; IT1014091B; ES425931A1; FR2228134B1; NL7405893A; DE2421553A1; AU6859674A; JPS5069704A; BE814358A; CA1007216A; AT331834B; DK143353B; LU69960A1; FR2228134A1; ATA364674A; OA04660A; DK143353C; ZA742778B

Abstract

A fastening device for fastening to a railway tie a rail comprising at least one resiliently yieldable fastening plate bearing on the flange of the rail and on the tie. The plate is provided with an aperture for the passage of plate-tightening means and has in its centre part, in the region of the aperture, a thickening defining a curved boss for bearing against the tightening means in a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail. The plate is thinned down progressively from the boss in the direction of each of the ends of the plate. The fastening pivots around the contact point as the rail vertically moves. The thickness of the plate however is constant adjacent its ends which form two thin very flexible feet. A boss may also be provided on the lower face of the plate.

Description

United States Patent Duchemin RESILIENTLY YIELDABLE RAIL FASTENING [75] Inventor: Michel Duchemin, Lambres Les Douai, France [73] Assignee: Ressorts du Nord S.A., Paris, France [22] Filed: May 3, 1974 [21] Appl. No.: 466,919

[30] Foreign Application Priority Data May 3, 1973 France n 7315918 [52] U.S. C1. 238/349; 238/283; 238/310 {51] Int. Cl. E0111 9/30 [58] Field of Search 238/349, 351, 310, 283

[56] References Cited UNITED STATES PATENTS 2,203,994 6/1940 Magee 238/349 2,526,005 10/1950 Carpenter 238/349 3,688,984 9/1972 Sonneville 238/349 3,784,098 1/1974 Serafin et al 238/349 June 10, 1975 Primary Examiner-M. Henson Wood. Jr.

Assistant Examiner-Richard A. Bertsch Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis [57] ABSTRACT A fastening device for fastening to a railway tie a rail comprising at least one resiliently yieldable fastening plate bearing on the flange of the rail and on the tie, The plate is provided with an aperture for the passage of plate'tightening means and has in its centre part, in the region of the aperture, a thickening defining a curved boss for bearing against the tightening means in a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail. The plate is thinned down progressively from the boss in the direction of each of the ends of the plate. The fastening pivots around the contact point as the rail vertically moves.

The thickness of the plate however is constant adjacent its ends which form two thin very flexible feet. A boss may also be provided on the lower face of the plate.

12 Claims, 4 Drawing Figures 20 1 f s a 7 2 1 a r I 1 1 PATENTEDJUH 10 ms SHEET FIG.2

FIG.5

RESILIENTLY YIELDABLE RAIL FASTENING As the speed of trains is constantly increasing and as their comfort must always improve. one is led to interpose, between the rail and the sleeper or tie supporting it, an elastically yieldable pad which is becoming thicker and thicker and more and more flexible, with result that the extent of the vertical movement of the rail increases which requires the use of increasingly flexible fastenings for fastening the rail to the sleeper.

Moreover, the fastening must oppose the tipping of the rail under the action of lateral forces exerted on its head, that is to say, the fastening must be strong enough to preclude any raising of the flange of the rail.

For this purpose, rails are generally fastened by means of fastenings in the form of spring plates or strips which bear, at one end, on the flange of the rail and, at the other end, on the support and are provided with an aperture for the passage of fastening-tightening means. However, the flexibility of the conventional fastenings is no longer sufficient.

An object of the present invention is to provide an extremely flexible and strong rail fastening device whereby it is possible to maintain a rail even when it is mounted on a very flexible pad.

According to the invention, there is provided a fastening device comprising at least one resiliently yield able fastening plate bearing on the flange of the rail on the sleeper and provided with an aperture for the passage of tightening means, the fastening comprising in its centre part in the region of the aperture a thickening constituting a curved boss for bearing against the tightening means at a point located between a bearing point or points between the fastening and the sleeper and a bearing point or points between the fastening and the rail flange, the fastening being progressively thinned down from the boss in a direction toward each of its ends.

Preferably, the plate terminates at each end beyond the thinned down part in a thin foot which has a substantially constant thickness.

Owing to its centre boss, the fastening is pivotable about its point of contact with the tightening means. Thus, when the elastically yieldable pad supporting the rail is depressed, it is completely relieved and contributes in its entirety at the maintenance of the rail. Now, the thinning down of the two parts of the fastening imparts to the branch bearing on the sleeper the same flexibility as the branch bearing on the rail, so that the fastening may have maximum flexibility. On the other hand, when the rail is at rest. the plate abuts against the head of the tightening means not only through its thickest part but also through the neighbouring portions lo cated between the boss and the flange of the rail. so that the rail is held completely stationary against any lateral tipping.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

In the drawings:

FIG. I is a longitudinal sectional view of a fastening according to the invention;

FIG. 2 is a plan view of the fastening shown in FIG. 1;

FIG. 3 is a sectional view of a rail fastening device employing the fastening shown in FIG. I;

FIG. 4 is a sectional view of a modification of the device shown in FIG. 3;

FIGS. 5 and 6 are sectional views of two other modi fications of the rail fastening device according to the invention;

FIG. 7 is a side elevational view of a modification of the fastening. and

FIG. 8 is a plan view of the fastening shown in FIG. 7.

The fastening shown in FIG. 1 comprises a resiliently yieldable metal strip or plate I provided with a centre aperture 2 for the passage of fastening-tightening means. This plate has in the region of the aperture 2 a thickening which forms a boss 4 on one of the faces of the plate. On each side of this boss, the thickness of the plate decreases progressively in the direction of each of its ends. However, this reduction in thickness stops preferably at 6 and 8 at a distance from said ends so that the plate I terminates in two thin very flexible feet 10, I2 of substantially constant thickness so that the fastening has on each side of the boss 4 two branches ll, 13 which are thinned down in a similar manner.

The surface 14 of the plate 1 opposite the boss 4 is preferably planar. This surface 14 is rectangular in the embodiment shown in FIG. 2, the feet I0 and I2 having the same width as the centre part of the plate. But the plate may have any other preferred shape, the feet It) and 12 being either wider or narrower than the rest of the plate.

In the fastening device shown in FIG. 3, the plate I bears at one end against the flange 16 of a rail [8 whereas at the other end it is in contact. through the foot 12. with the sleeper or tie T which supports this rail. A coach-screw 20 extends through the aperture 2 and is screwed in the sleeper T. A head 22 of this coach-screw exerts a force on the upper surface of the plate I in the region of the boss 4 and applies the fas tening against the flange 16 of the rail as shown in FIG. 3 in constraining it to flex and bend.

The c ..ach-screw 20 is sufficiently near to the flange 16 to alow its head 22 to extend slightly over the flange so that the tightening down of the fastening plate is limited by the contact of the plate 1 with the edge 17 of this flange. In this position, the foot 10 of the fastening is clamped or tightened against the flange I6 and is in full contact therewith with a uniformly-distributed pressure. The head 22 bears, as shown in the drawing, not only on the top of the boss 4 but also on the neigh bouring part of the plate I, that is to say, on the thickest part of the branch 11. Thus no raising of the rail I8 is possible. On the other hand, on the other side of the coach-screw 20, a space 24 remains free between the head 22 and the branch 13 and the foot 12 is in full contact with and exerts a uniformly-distributed pressure on the sleeper.

The rail 18 is mounted on the sleeper T with interposition ofa pad 25 composed of a very flexible elastically yieldable material. Consequently, when a train passes over the rail and its weight compresses the pad 25 and moves the flange l6 nearer to the sleeper T, the branch II of the plate I is untightened and leaves its support under the head 22 and only the top of the boss 4 remains in contact with the head. There results a reliev ing of said plate I and a pivoting of the fastening about this single point of contact with the head 22. The thickening of the boss 4 promotes this pivoting and performs the function of an articulation or pivot so that the whole of the plate that is to say. both branch 13 and branch 11 participates in the flexibility. only the foot 12 remaining rigid. The force exerted by the tightening means remains applied at its point of contact with the plate and the reaction on the rail and on the sleeper are respectively localized in the regions of the feet and 12.

There is thus provided a fastening which has very high resilience with great strength. A fastening of maximum flexibility, which is that in which each section has a modulus of inertia proportional to the bending moment applied thereto. can be easily constructed. the increase in the thickness in the vicinity of the aperture 2 compensating for the reduction in the useful width.

It will be understood that the circular aperture 2 shown in FIG. 2 may be replaced. in order to facilitate the assembly. by a longitudinal notch without modifying in a marked manner the strength of the assembly. It is sufficient to conserve the same shape for the upper face of the branch 13 which extends over the sleeper.

Moreover. in some cases. it may be preferable to pro vide the lower surface 14 of the plate 1 also with a boss constituted in the same way as the boss 4 by a local thickening of the plate in the opposite direection. The second boss constitutes a bearing point on the sleeper T and defines a free space between this bearing point and the foot 12 in contct with the sleeper. This lower boss is preferably exactly opposite the boss 4 and, in the same way as the latter, coaxialwith the aperture 2. However. this second boss may be. in the same way as the upper boss. laterally offset from the aperture 2. FIG. 4 shows an embodiment of this type. It shows a de vice for fastening a rail to a sleeper or tie T, of concrete in which the fastening is constituted by a plate or strip 3i which has, in the same way as the plate 1, a boss 26 on its upper face in the region of the aperture 32 for the passage of the tightening means 30, but this boss is not centred on this aperture but laterally offset onto the branch 27 of the fastening adapted to bear on the flange 16 of the rail. The plate 31 further comprises on its lower face a second boss 28 which is also laterally offset from the aperture 32 for the passage of the tightening means but in the direction of the opposite end, that is to say. on the branch 29 which is adapted to come in contact with the sleeper.

The rail 18 is disposed in a recess 34 in the sleeper T of concrete. bears against a pad 35 and is blocked or retained laterally by means of blocks 36 which are preferably of an electrically insulating material and fill the recess 34 on each side of the rail 18 and extends along the upper part of the corresponding flange 16.

The branch 27 of the plate is tightened against this insulating block 36 by means of a nut 38 screwed on the bolt 30. The nut 38 is in contact with the boss 26 and with the neighbouring portion of plate 31. On the other hand. a space 40 remains empty on the other side of the bolt between the latter and the part of the plate 31 which is located directly above the boss 28. In the same way as in the device shown in FIG. 3. when the flange of the rail compresses the pad 35, the plate 31 pivots about the point of Contact of the boss 26 with the nut 38 which raises the boss 28 off the sleeper and enables the whole of the plate to participate in the resilience of the fastening. On the other hand. when the device is in the illustrated position. the whole of the plate located between the boss 28 and the flange l6 constitutes a relatively thick means which is sufficiently rigid 4 to strongly maintain the rain against any lateral tipping notwithstanding the fact that the nut 38 does not extend over the flange 16.

The fastening plate provided with a thickening at its 5 centre part may also be employed for other types of sleepers or ties. In particular. it may b rnounted on metal sleepers provided with lateral abutments or stops on each side of the position of the rail. such as those shown in FIGS. 5 and 6. in this case. the fastening 41 extends over the abutment and the tightening bolt 42 extends in succession through the aperture in the plate and an aperture in the abutment 48. The fastening 41 is therefore not only thinned down but also curved in such manner as to allow the foot 46 at the end of the branch 45 to come in contact with the sleeper. whereas the foot 44 of the opposite branch 43 bears against the flange 16 on the other side of the abutment 48. This fastening comprises an upper boss 50 in contact with the tightening bolt and preferably a lower 52 on the op posite side of the plate and in contact with the abutment 48. A lateral packing block 54 constituting an electrically insulating cladding is interposed between the flange 16 of the rail, the abutment 48 and the branch 43 of the fastening 44. This branch 43 is tightened against the flange l6 and is in contact with the latter in the region of the foot 44 and in the region of the edge 17 of this flange. However, as the branch 45 is only in contact with the sleeper by the foot 46, the fastening pivots with respect to the tightening means 42 in the same way as the fastenings l and 31 when the pad is compressed.

The lateral abutment 48 may be a projecting portion integral with the sleeper or constituted by an independent member 58 which extends through an aperture 56 in the sleeper as shown in FIG. 6. The abutment 58 is then hollow and maintained in position, together with the fastening 41, by the tightening means 42.

It must be understood that the fastening may be constituted by a single plate or strip or by a plurality of plates or strips in superimposed relation forming together the thickening constituting the upper boss and. if provided, a lower boss (FIGS. 7 and 8). For example, a fastening 60 may comprise a lower plate or strip 62 of constant thickness and adapted to bear against the sleeper adjacent one end of the strip 62 and against the flange of the rail adjacent the other end, this lower plate being associated with a second plate or strip 64 whose thickness varies and is maximum in the centre part at 65. The two plates are'provided in this centre part with an aperture 66 for the passage of tightening means. The thickness of the second plate 64 decreases progressively from the aperture 66 to its ends. However, its length is less than that of the plate 62 and the ends of the latter form on each side of the plate 64 two thin feet of constant thickness. The width of the plate 64 may be the same as that of the plate 62 or less and decrease progressively at the same time as the thickness decreases in the direction of each of the ends of the fastening.

Other plates or strips may also be superimposed on the

plates

62 and 64 or. in some cases. the fastening may have a plurality of plates or strips whose thicknesses. and possibly widths. are variable. Such an assembly of superimposed plates constitutes. in the same way as a single plate. a very strong fastening which is nonetheless highly flexible. Preferably. the thickness and the width of the plates are so chosen that each section has a modulus of inertia which is proportional to the bending moment applied thereto so as to achieve maximum flexibility.

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

l. A fastening device for fastening to a railway tie a rail which has a flange and is supported by the tie through an elastically yieldable pad, comprising a fastening comprising at least one resiliently yieldable plate bearing, in a first branch adjacent one end of the fastening at at least one point of the fastening, against the tie and, in a second branch adjacent an opposite end of the fastening at at least one point of the fastening, against the flange of the rail, means defining in the plate an aperture, between the two branches, the fastening having a thickening in a centre part of the fastening in the region of the aperture constituting a curved boss, the fastening progressively thinning down from the boss in directions toward said ends of the fastening", and tightening means for tightening down the fastening onto the rail flange extending through the aperture and connected to the tie, the tightening means being pivotally engaged with the upper face of the boss at a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail, whereby said fastening pivots around said contact point as the pad is compressed or depressed by the rail.

2. A fastening device as claimed in claim 1, having a constant thickness in the vicinity of each of said ends so as to constitute a foot adjacent each end, its thickness decreasing between said boss and said feet.

3. A fastening device as claimed in claim 1, compris ing a plurality of superimposed plates of which at least the uppermost plate has a thickening in its centre part.

4. A fastening device as claimed in claim 3, comprising at least one plate of constant thickness and a plate of variable thickness.

5. A fastening device as claimed in claim 1, wherein the boss has a width which decreases on each side of the aperture in the directions of said ends.

6. A fastening device for fastening to a railway tie a rail which has a flange and is supported by the tie through an elastically yieldable pad, comprising: a fastening comprising at least one resiliently yieldable plate bearing, in a first branch adjacent one end of the fastening at at least one point of the fastening, against the tie and, in a second branch adjacent an opposite end of the fastening at at least one point of the fastening, against the flange of the rail, means defining in the plate an aperture between the two branches, the fastening having a thickening in a centre part of the fastening in the region of the aperture constituting a curved first boss, the fastening progressively thinning down from said first boss in directions toward said ends of the fastening; and tightening means for tightening down the fastening onto the rail flange extending through the aperture and connected to the tie, the tightening means being pivotally engaged with the upper face of said first boss at a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail and a second boss on the opposite side of the fastener to the first boss, whereby said fastening pivots around said contact point as the pad is compressed or depressed.

7. A fastening device as claimed in claim 6, wherein the two bosses are exactly aligned with each other,

8. A fastening device as claimed in claim 6 wherein the two bosses are laterally offset with respect to each other and with respect to the aperture, the offsets being respectively in directions toward said ends.

9. A device for fastening to a railway tie a rail which has a flange and is supported by the tie through an elastically yieldable pad, comprising: a fastening comprising at least one resiliently yieldable plate bearing. in a first branch adjacent one end of the fastening at at least one point of the fastening, against the tie and, in a second branch adjacent an opposite end of the fastening at at least one point of the fastening, against the flange of the rail, means defining in the plate an aperture. the fastening having a thickening in a centre part of the fastening in the region of the aperture constituting a curved boss, the fastening progressively thinning down from the boss in directions toward said ends of the fastening; and tightening means for tightening down the fastening onto the rail flange extending through the aperture and connected to the tie, the tightening means being in contact with the boss and with a portion of the second branch of the fastening, there being defined between the tightening means and the first branch of the fastening a free space, the end of the fastening corresponding to said first branch being flat on the tie. the boss bearing against the tightening means at a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail.

10. A device as claimed in claim 9, comprising an abutment for limiting the lateral displacement of the rail relative to the tie and integral with the tie and located between the rail and the tightening means, and a lateral electrically-insulating rail-blocking packing block interposed between a side of the rail and said abutment and covering an upper part of the flange of the rail, the second branch of the fastening bearing on said block.

11. A device as claimed in claim 10, wherein the abutment is formed by a side of a projecting portion in one piece with the tie and the tightening means is fixed in said projecting portion.

12. A device as claimed in claim 10, wherein the abutment comprises an attached member which is fixed to the tie by the tightening means. i

Claims

1. A fastening device for fastening to a railway tie a rail which has a flange and is supported by the tie through an elastically yieldable pad, comprising : a fastening comprising at least one resiliently yieldable plate bearing, in a first branch adjacent one end of the fastening at at least one point of the fastening, against the tie and, in a second branch adjacent an opposite end of the fastening At at least one point of the fastening, against the flange of the rail, means defining in the plate an aperture, between the two branches, the fastening having a thickening in a centre part of the fastening in the region of the aperture constituting a curved boss, the fastening progressively thinning down from the boss in directions toward said ends of the fastening; and tightening means for tightening down the fastening onto the rail flange extending through the aperture and connected to the tie, the tightening means being pivotally engaged with the upper face of the boss at a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail, whereby said fastening pivots around said contact point as the pad is compressed or depressed by the rail.

3. A fastening device as claimed in claim 1, comprising a plurality of superimposed plates of which at least the uppermost plate has a thickening in its centre part.

7. A fastening device as claimed in claim 6, wherein the two bosses are exactly aligned with each other.

9. A device for fastening to a railway tie a rail which has a flange and is supported by the tie through an elastically yieldable pad, comprising: a fastening comprising at least one resiliently yieldable plate bearing, in a first branch adjacent one end of the fastening at at least one point of the fastening, against the tie and, in a second branch adjacent an opposite end of the fastening at at least one point of the fastening, against the flange of the rail, means defining in the plate an aperture, the fastening having a thickening in a centre part of the fastening in the region of the aperture constituting a curved boss, the fastening progressively thinning down from the boss in directions toward said ends of the fastening; and tightening means for tightening down the fastening onto the rail flange extending through the aperture and conneCted to the tie, the tightening means being in contact with the boss and with a portion of the second branch of the fastening, there being defined between the tightening means and the first branch of the fastening a free space, the end of the fastening corresponding to said first branch being flat on the tie, the boss bearing against the tightening means at a contact point located between a region in which the fastening bears against the tie and a region in which the fastening bears against the flange of the rail.

12. A device as claimed in claim 10, wherein the abutment comprises an attached member which is fixed to the tie by the tightening means.