Patent Application
20090001187
The present invention relates to a restoration insert for a railway rail anchor to a wooden sleeper.
Railway rails are fixed to wooden sleepers using metal sleeper screws screwed into the sleepers. Over time, moisture penetrates between some sleeper screws and the sleepers, degrading the wooden zones in which these sleeper screws are anchored. The result is that the sleeper screws work loose from the sleepers, decreasing fixing of the rails. This loosening is marked by the stress transmitted by the passage of trains, which moreover cause a certain erosion of the wood of the sleeper after repeated friction. This erosion leads to out-of-roundness of the holes in the upper part, giving these holes a conical shape when viewed in cross-section. It is then necessary to restore anchoring of the rails to the sleepers.
To do this, it was proposed to use an insert placed in the hole of the sleeper before screwing the sleeper screw back in, this insert thus being squeezed between the sleeper screw and the sleeper. The restoration process using this insert comprises the steps of removing the relevant sleeper screw, placing the insert in the hole to be treated, depositing a hardenable fluid product in the hole, this product being able to flow into the fibers of the wood, and screwing the sleeper screw back in, so as to squeeze the insert between this sleeper screw and the wall of the hole, thus making said hardenable fluid product flow around this sleeper screw and the insert.
The existing insert is thus satisfactory overall but is, however, subject to improvement.
Indeed, it has been shown that the existing insert cannot enable sufficiently solid restoration of an anchor, particularly in the case of enlarged and more or less ovalized holes in the upper part. It is certainly possible to put two inserts in place, but there is then the risk that one or both of the two inserts will move angularly in relation to each other when the sleeper screw is put back into place.
There also appears to be a risk of the hardenable product leaking at the lower end of the hole, this hole generally opening at the lower surface of the sleeper.
The present invention aims to resolve these drawbacks.
One purpose of the invention is therefore to provide a restoration insert for a railway rail anchor on a wooden sleeper, allowing solid restoration of an anchor even in the case of enlarged or more or less ovalized holes in the upper part.
Another objective of the invention is to provide an insert having a limited risk of angular or axial movement in the hole when the sleeper screw is put back into place.
An additional objective of the invention is to provide an insert which limits the risk of leakage of the hardenable product at the lower end of the hole.
To achieve at least one of these objectives, the insert according to the invention comprises:
two primary lateral parts, sized to extend, after placement of the insert in the hole, over a large portion of the height of this hole, alongside each other; and
a central part whereto are connected the two primary lateral parts, this central part being disposed, after placement of the insert in the hole, substantially perpendicular to said primary lateral parts and being sized to cover a large portion of the cross-section of the hole.
The insert according to the invention thus comprises two primary lateral parts intended to be squeezed between the sleeper screw and the wood of the sleeper, which allows solid restoration of the anchor, even in the case of enlarged or more or less ovalized holes in the upper part. The link between these two primary lateral parts to said central part makes it possible to maintain the relative position of the primary lateral parts in relation to each other at the beginning of screwing the sleeper screw back in and thus to effectively avoid a risk of angular movement of the primary lateral parts relative to each other. The bearing of the two primary lateral parts against the wood of the sleeper makes it possible to increase friction between the insert and the sleeper, and therefore to reduce the risk of axial movement of the insert at the beginning of screwing the sleeper screw back in.
Said central part also makes it possible, because of its dimensions and its link to the two primary lateral parts, to strongly reduce the risk of the hardenable product escaping outside the hole.
Preferably, the insert according to the invention is made of a material able to be bent and, before use, its two primary lateral parts are located on either side of the central part, on the extension of each other.
The insert is thus manufactured following this elongated shape, and its two primary lateral parts must be bent according to angles close or equal to a right angle relative to its central part when it is placed in the hole to be treated. Manufacturing of the insert, in particular its molding in a synthetic material, is made easier. Moreover, if the material making up the insert presents a slight elastic flexibility, the elastic return of this material increases the support force of the primary lateral parts against the sleeper after placement and consequently favors resistance of the insert to axial movement in the hole.
The primary lateral parts may be connected to the central part by flexible zones, in particular, if the insert is in a molded synthetic material, by film hinges.
The primary lateral parts are preferably located on two sides opposite said central part, such that, after placement of the insert in the hole to be treated, they find themselves facing each other at the two diametrically opposed zones of this hole.
The primary lateral parts preferably have, at their portions connected to the central part, widths which decrease as they approach this central part.
This reduction in width favors the introduction of the insert in the hole to be treated and allows an increased possibility of deformation of the primary lateral parts at their zones connected to the central part.
Each primary lateral part is preferably in the shape of a longitudinal tube portion, meaning having a concave surface on one side and a convex surface on the opposite side, the concave surfaces of the two primary lateral parts, after placement of the insert, being turned toward each other.
This shape of the primary lateral parts is thus suited to the shape of the holes and the sleeper screws.
Each primary lateral part advantageously comprises through holes, which put its surface intended to be turned toward the inside of the hole in communication with its surface intended to be against the sleeper.
These holes favor spreading of the hardenable product through these primary lateral parts.
At least one primary lateral part may comprise substantially transverse and/or longitudinal ribs, protruding from its surface intended to bear against the sleeper, and/or internal grooves developed from its surface intended to face the sleeper screw side, these internal grooves being disposed so as to correspond substantially to the thread of the sleeper screw.
These ribs favor the bearing of this primary lateral part against the sleeper, and the internal grooves make it possible, once the insert is placed in the hole, to form a threaded portion intended to receive the thread of the sleeper screw.
At least one primary lateral part may comprise a strip extending its end opposite the end connected to said central part, having a reduced thickness, for example a thickness of approximately 1 mm.
This strip makes it possible to facilitate orientation of the insert after placement in the hole, in order to give this insert the most appropriate angular position depending on the shape of the hole.
Advantageously, in this case, the surface of the strip intended to be located toward the interior of the hole after placement of an insert is found in the extension of the surface of the primary lateral part comprising this strip intended to be located toward the interior of the hole after placement of the insert.
The primary lateral part then does not comprise an upper edge against which the sleeper screw risks bearing when it is screwed back in, such that the risk of axial movement of the insert during this screwing back in is reduced by as much.
The invention will be well understood, and other characteristics and advantages will appear, in reference to the annexed diagrammatic drawing, this drawing illustrating, as a non-exhaustive example, a preferred embodiment of the insert in question.
The railway rails are fixed to wooden sleepers 100 (cf.
The restoration procedure consists of removing the relevant sleeper screw, placing the insert 1 in the hole 101 to be treated, depositing a hardenable fluid product in the hole, this product being able to flow into the fibers of the wood, and screwing the sleeper screw back in, so as to squeeze the insert 1 between this sleeper screw and the wall of the hole, thus making said hardenable fluid product flow around this sleeper screw and the insert 1.
In reference to
The insert unit 1 is made by molding a synthetic material, the bendable zones 4 being made up of film hinges. As molded, the insert 1 appears as shown in
The bendable zones 4 are such that the two primary lateral parts 2 may be bent toward each other relative to the central part 3 as shown in
The primary lateral parts are sized to extend, after placement of the insert I in the hole 101, on a large portion of the height of this hole, as may also be seen in
They present, at their portions connected to the central part 3, widths which become smaller as they move toward this central part.
As appears in
Each primary lateral part 2 also comprises staggered holes 5 which cross it, these holes putting the surfaces 2a and 2b of the primary lateral part 2 in communication. This latter part also comprises substantially transverse ribs 6 and longitudinal ribs 7 on its convex surface 2b, as well as internal grooves 8 laid out from its concave surface 2a, these grooves 8 being disposed so as to correspond substantially to the thread of the sleeper screw.
Each primary lateral part 2 also comprises a strip 9 extending its end opposite the end connected to the central part 3, having a reduced thickness, for example a thickness of approximately 1 mm. The surface of the strip 9 being on the side of the concave surface 2a finds itself in the extension of this surface 2a.
The central part 3 is sized so as, after placement of the insert 1, to cover a large portion of the cross-section of the hole, as shown in
In the illustrated example, it has a flattened conical shape, the cone protruding from the same side as that on which the convex surfaces 2b are found.
In practice, as can be understood in reference to
The synthetic material making up the insert 1 advantageously has a slight elastic flexibility, such that the elastic return of this material allows the existence of a slight support force of the primary lateral parts 2 against the sleeper 100. This slight support force, together with the ribs 6 and 7 and the primary lateral parts 2 at the central part 3, favors resistance of the insert 1 to an angular or axial movement in the hole 101 when the sleeper screw is screwed back in.
The development of the internal surfaces of the strips 9 in the extension of the concave surfaces 2a eliminates the presence of any upper edges on the insert 1, against which the sleeper screw risks bearing when it is screwed back in, which contributes to reducing the risk of angular or axial movement of the insert during this screwing back in. The upper ends of the strips 9 may be slightly flared, as shown, to form an entrance favoring reinsertion of the sleeper screw.
Once the insert 1 is in the position shown in
This screwing of the sleeper screw results in squeezing the primary lateral parts 2 between itself and the sleeper 100 and causing the flow of said hardenable product in the fibers of the wood, in particular, thanks to the holes 5, through the primary lateral walls 2. The central part 3 makes it possible, due to its dimensions and its link to the two primary lateral parts, to strongly reduce leakage of the hardenable product outside the hole 101, which opens into the lower face of the sleeper 100.
As appears from the preceding, the invention provides a restoration insert for a railway rail anchor having, relative to similar inserts of the prior art, the determining advantages of allowing solid restoration of the anchor even in the case of enlarged or more or less ovalized holes in the upper part, presenting limited risk of angular or axial movement in the hole when the sleeper screw is screwed back in, and limiting the risk of leakage of the hardenable product at the lower end of the hole.
It goes without saying that the invention is not limited to the embodiment described above as an example, but that it extends to all embodiments covered by the annexed claims.
