WO2022258650A1

WO2022258650A1 - Improved measurement system for longitudinal displacements or sliding of a rail, also for checks on tracks in operation

Info

Publication number: WO2022258650A1
Application number: PCT/EP2022/065472
Authority: WO
Inventors: Giorgio Pisani
Original assignee: Giorgio Pisani
Priority date: 2021-06-10
Filing date: 2022-06-08
Publication date: 2022-12-15
Also published as: EP4352453A1; IT202100015224A1

Abstract

A measurement system for longitudinal displacements or sliding of at least one rail (1), in particular of a long welded rail (1), comprising: centering means (101, 103) configured to anchor the measurement system to at least one reference support (3, 4); an optical collimation device (102) adapted to generate a collimation plane (2), unique with respect to the at least one reference support (3, 4) and projectable onto at least one web of the rail (1), to perform a position reading of at least one fixed mark on the rail (1); a displacement device (105) configured to provide a lateral displacement of the collimation plane (2'); a sensing device (106) configured to measure the lateral displacement for the position reading of the at least one fixed mark.

Description

Title: Improved measurement system for longitudinal displacements or sliding of a rail, also for checks on tracks in operation

DESCRIPTION

Technical field

The present invention relates to a measurement system for longitudinal displacements or sliding of at least one rail, in particular of a long welded rail.

In general, the present invention finds its application in the field of measurement of longitudinal displacements of a rail, in particular made in Long Welded Rail (L.W.R.), by means of optical measurements even on tracks in operation.

The present invention, in particular, is effectively usable on railway lines where tracing references consisting of the so-called “topographic pegs” are available.

Prior art

The variation of the Neutral Temperature (N.T.) of a rail made in Long Welded Rail (L.W.R.) on the tracks in operation may be determined based on the longitudinal displacements undergone by the rail itself over time. N.T. of a rail indicates that temperature at which, at the time of creation in L.W.R. , internal stresses (of elongation or shortening) of the rail itself are not present.

The control operations involve conducting measurements of the longitudinal displacements on the L.W.R. during operation, verifying that each of the two rails of the track undergoes - over time - just longitudinal movements compatible with respect to the position created at the time of the internal tension adjustment of the of the L.W.R. itself.

International patent application published under no. W02008129420A3 in the name of Giorgio Pisani relates to a laser measurement method and system for checks even in operation and under construction, of longitudinal displacements of a L.W.R., which involves performing a first series of reference measurements by means of a laser distance meter and reflection sights, and performing subsequent series of test measurements by means of laser distance meter and reflection sights, in particular by rotating the laser distance meter on the two X and Y axes.

Patent application for industrial invention no. IT 102018000005257 filed on 10/05/2018 entitled: “Measurement method and system for longitudinal displacements or sliding of at least one rail, in particular of a long welded rail, for checks even on railway tracks in operation” in the name of Giorgio Pisani relates to a measurement system for longitudinal displacements or sliding of a long welded rail, comprising an anchoring and centering to a reference support and a collimation device adapted to generate in a repeatable manner over time a unique collimation plane projectable onto at least one web of the rail.

While allowing considerable savings in time and personnel, the prior art solutions are not fully effective as regards the measurement of displacements or sliding even with the track in operation.

For instance, to evaluate the distance between the generated collimation plane and the mark on the rail, it is sometimes necessary to access the railway site, both to carry out a more precise detection from a short distance, and to carry out maintenance or installation of optical/ electronic references fixed on the rail.

Having to access the railway site, on the one hand it is appropriate to suspend the circulation of trains at least temporarily, with obvious inconveniences on the line. Having to access the railway site, a risk arises on the other hand, for instance of injury or being run over, to which the operators are exposed. Therefore, the prior art solutions may still be improved in certain aspects, by solving technical problems thereof.

Summary of the invention

An object of the present invention is to overcome prior art drawbacks.

A particular object of the present invention is to avoid having to access the track to measure longitudinal displacements or sliding, thus increasing the safety of operators and railway traffic.

A particular object of the present invention is to provide a measurement system for longitudinal displacements or sliding of at least one rail, which is more effective.

A further particular object of the present invention is to provide a measurement system for longitudinal displacements or sliding of at least one rail which allows a more immediate measurement.

A further particular object of the present invention is to provide a measurement system for longitudinal displacements or sliding of at least one rail which allows carrying out of all the control operations required by the regulations in force on the Long Welded Rail even by one person and without interfering with the movement of trains on the track in operation.

These and other objects are achieved by means of a measurement system for longitudinal displacements or sliding of at least one rail, in particular a Long Welded Rail, according to the appended claims which form an integral part of the present description.

An idea underlying the present invention is to provide a measurement system for longitudinal displacements or sliding of at least one rail, comprising: centering means configured to anchor the measurement system to at least one reference support; an optical collimation device adapted to generate a collimation plane, unique with respect the at least one reference support and projectable onto at least one web of the rail, to perform a position reading of at least one fixed mark on the rail; a displacement device configured to provide a lateral displacement of the collimation plane; a sensing device configured to measure the lateral displacement for the position reading of the at least one fixed mark. Preferably, the displacement device comprises an optical transformation device acting on the collimation plane.

The present invention, advantageously, allows performing the detection and measurement of the longitudinal displacements of the at least one track, evaluating the displacement of the fixed mark on the rail with respect to an original collimation plane; the displacement is measured causing the generated collimation plane to displace laterally by an amount corresponding to the longitudinal displacement undergone by the track, causing it to coincide with the fixed mark in its new position.

Advantageously, the present invention allows operators to avoid access the track and to perform detections from the walkway lateral to the track, even in the presence of active railway traffic.

Advantageously, the present invention allows reproducing over time, for each reference support on which the system is hooked, always the same collimation plane. Preferably, the collimation plane thus generated intercepts the two rails of the facing track through a luminous dot or line and allows measuring over time, with respect to the original mark on each track, a longitudinal displacement of the rails.

Advantageously, the measurement system allows conducting all of the control operations required by the regulations in force on the Long Welded Rail even by a single person and above all without interfering with the movement of trains on the track in operation.

Advantageously, the present invention allows a calculation of the thermal stress status of the Long Welded Rail upon each detection, through the use of a calculation model that correlates the variation of Neutral Temperature with the longitudinal sliding of the rails.

Advantageously, the present invention allows an automatic drafting of specific verification tables for the certification of the thermal stress status of the Long Welded Rail upon the detection.

Further features and advantages will become more apparent from the detailed description made below of preferred non-limiting embodiments of the present invention, and from the dependent claims which outline preferred and particular embodiments of the invention.

Brief description of the drawings

The invention is illustrated with reference to the following figures, provided by way of non-limiting example, wherein:

- Figure 1 illustrates a side view of a preferred embodiment of a measurement system according to the present invention.

- Figure 2 illustrates a top view of Figure 1.

- Figure 3 exemplifies the schematic constitution of a collimation plane.

- Figure 4 illustrates a side view of the measurement system in a first operating condition.

- Figure 5 illustrates a side view of the measurement system in a second operating condition.

- Figure 6 illustrates a top view of Figure 5.

- Figure 7 illustrates a side view of the measurement system in a third operating condition.

- Figure 8 illustrates a top view of Figure 7.

- Figure 9 illustrates a perspective view of a module constituted by the displacement device and the sensing device of the measurement system according to the present invention.

- Figure 10 illustrates the module of Figure 9 separated from the body of the measurement system according to the present invention.

- Figure 11 illustrates a first embodiment of centering means of the measurement system according to the present invention.

- Figure 12 illustrates a second embodiment of centering means of the measurement system according to the present invention.

In the different figures, similar elements will be identified by similar reference numbers.

Detailed description

Figure 1 illustrates a side view and Figure 2 illustrates a top view of a preferred embodiment of a measurement system 100 according to the present invention.

Said measurement system 100 is usable for measuring longitudinal displacements and sliding of a rail, in particular of a long welded rail.

The measurement system 100 comprises centering means 101 configured to anchor the measurement system 100 to a reference support, as it will be further described.

The measurement system 100 further comprises an optical collimation device 102 adapted to generate a collimation plane, unique with respect to the reference support and projectable onto at least one web of the rail, to perform a position reading of at least one fixed mark on the rail, as it will be further described.

Tale optical collimation device 102, in a preferred embodiment, comprises a laser-type light source, adapted to project a dot or vertical dash on a web of a rail. Preferably, the centering means of the measurement system 100 further comprise a subsidiary reference element 103 configured to coincide with a fixed reference, such as a hole, associated with the reference support. Said subsidiary reference element 103 is adapted to constrain the rotation with respect to the reference support of the cylindrical clench 101, ensuring the repeatability over time of the projection of the collimation plane.

Preferably, the measurement system 100 further comprises a slope adjustment element 104, configured to vary a slope of the optical collimation device 102 on the collimation plane, thus generating a plurality of laser beams, in the example, which identify the collimation plane.

The measurement system 100 further comprises a displacement device 105 configured to provide a lateral displacement of the collimation plane, and a sensing device 106 configured to measure the lateral displacement, allowing the position reading of the fixed mark on the rail.

In the preferred embodiment, the displacement device 105 comprises an optical transformation device 107 which comprises a plane-parallel plate or one or more prisms, optically equivalent to a plane-parallel plate.

The module 107, thanks to the plane-parallel plate, allows the lateral displacement, in a quick and accurate manner, of the collimation plane, in particular laterally displacing the laser beam generated by the optical collimation device 102 parallel to the optical axis thereof.

In fact, a rotation on the support plane of the plane-parallel plate 107 will cause a corresponding parallel displacement of the optical beam, for instance of the laser beam, passing through the plane-parallel plate 107. This displacement, in addition to the rotation angle, is due to optical refractive effects depending on the thickness of the plate 107 and to its refractive index, according to Snell’s Law.

In particular, for a zero incidence angle on the plate 107 (i.e. perpendicular to the surface of the plate) the lateral displacement of the collimation plane will also be zero.

Figure 3 exemplifies the schematic constitution of a collimation plane at a pair of rails 1.

As described, the measurement system 100 comprises an optical collimation device 102 adapted to generate the collimation plane 2.

The collimation plane 2 is in particular unique with respect to the reference support 3 and is projectable onto at least one web of the rails 1, so as to perform a position reading of at least one fixed mark on the rail 1.

Preferably, the reference support 3, which the measurement system 100 is anchored to, comprises a topographic peg 3, in particular a peg 3 of the type already installed on railway lines and is also used to check the plano-altimetric status of the rail 1.

The use of the topographic peg 3 allows uniquely defining the collimation plane 2 thus advantageously exploiting an infrastructure already available in the railway sector. In fact, said topographic pegs 3 are advantageously already installed on the electric traction poles or on other existing artifacts, with immovability features. Therefore, their use has the purpose of facilitating the detection operations, improving data accuracy, and reducing costs.

Preferably, a further fixed reference 4, such as a hole, is associated with the reference support 3, said further fixed reference 4 allows assuring the positioning of the measurement system 100 as already described.

Alternatively, it would be possible to use, for the measurement system 100, different fixed or movable physical supports as reference. Briefly illustrating the general operation of the measurement system 100, the collimation plane 2, preferably generated by a laser source that projects a bright dot or line, is projected on the track 1, in particular constituted in L.W.R. On the web of the rail 1 a fixed mark (not visible in the figure) is present. According to the present invention it is not necessary to have a further horizontal millimetric reference (fixed or removable), which could still be present and whose central zero would coincide with the initial fixed mark. The measurement method provides repeatably generating over time the collimation plane 2 projected on the web of the rail 1, from the reference support 3. Preferably, the bright dot or line defining the collimation plane 2 may be moved over the entire height of the two rails 1 of the facing track. As described, the displacement device 105 of the measurement system 100 allows providing a lateral displacement with respect to the collimation plane 2, to make it coincide again with the fixed mark in case of displacement or sliding of the track 1.

Moreover, the sensing device 106 of the measurement system 100 is configured to measure the elapsed lateral displacement, thus allowing the position reading of the fixed mark on the rail.

In other words, the position reading is performed by detecting a distance existing between the original projection of the unique collimation plane 2, and the laterally displaced projection of the collimation plane 2’ led to coincide with the fixed mark on the rail 1, which displaced as a result of the displacement or sliding of the rail 1.

The unique collimation plane 2 is in particular defined at a first installation right as the plane passing through the center of the topographic peg 3, which a fixed mark on the rail is associated 1 with. The unique collimation plane 2 will be compared, every time a measurement is made, with the current position of the fixed mark that was made on the web of the rail 1 upon the first installation.

The present invention thus allows measuring the longitudinal sliding of the rails 1 in successive instants of time, by intersection with the collimation plane 2 suitably laterally displaced.

Figure 4 illustrates a side view of the measurement system 100 in a first operating condition.

Preferably, the optical transformation device 105 is separatable from the optical collimation device 102 to free the optical path and generate a collimation plane 2 devoid of any lateral displacement.

In particular, in this operating condition the plane-parallel plate 107 is removed from the optical path, thus ensuring in a simple and defined way that there is no lateral displacement of the collimation plane.

Alternatively, the plane-parallel plate 107 could be left installed, taking care to exactly center the collimation plane on the ‘zero’.

Moreover, it should be noted that the sensing device 106 configured to measure the lateral displacement of the collimation plane is currently in a position that does not intersect the optical path of the collimation plane 2.

Figure 5 illustrates a side view and Figure 6 illustrates a top view of the measurement system 100 in a second operating condition.

The displacement device 105 is in general configured to provide a lateral displacement of the collimation plane 2’.

In the preferred embodiment, the optical transformation device 107 comprises a pair of surfaces 107a and 107b, respectively configured for a double refraction of the collimation plane 2, maintaining a direction of the collimation plane 2 and providing a lateral displacement in a parallel manner to define the collimation plane 2’.

Preferably, the optical transformation device 107 further comprises un rotation element 108, such as a pin, configured to rotate the optical transformation device 107 about an own vertical axis. Said pin 108 could comprise or be associated with further rotation locking elements.

Figure 7 illustrates a side view and Figure 8 illustrates a top view of the measurement system 100 in a third operating condition.

In this operating condition, the sensing device 106 is used to measure the lateral displacement of the collimation plane 2’, with the purpose of performing a position reading of the at least one fixed mark on the rail

1.

In the preferred embodiment, the sensing device 106 comprises a graduated element 106b configured to be selectively interposed on the optical path of the collimation plane 2’, downstream of the optical transformation device 107.

The interception of the collimation plane 2’, in displaced conditions, on the graduated element 106b allows measuring the lateral displacement of the collimation plane 2’ with respect to a predetermined center corresponding to the original collimation plane 2.

In particular, the graduated element 106b comprises at least one rotatable movement hinge 106a, and it is thus movable to interpose in or to free the optical path of the collimation plane 2’.

In particular, the graduated element 106b is rotatable on an axis transversal to the collimation plane 2 or 2’ of the measurement system 100.

Figure 9 illustrates a perspective view of a module 200 constituted by the displacement device 107 and by the sensing device 106 of the measurement system 100, whereas Figure 10 illustrates the module 200 separated but close to the body of the measurement system 100.

Preferably, the displacement device 105 comprises a plane-parallel plate 107 suitably protected by a metal casing.

The module 200 preferably comprises a precision coupling system 201, which ensures that the collimation plane actually passes on the central zero of the sensing device 106.

Thanks to the coupling system 201, the module 200 may be separated and newly coupled to the measurement system 100. The measurement system devoid of the module 200, in fact, remains adapted to generate a collimation plane thanks to the optical collimation device 102.

The module 200, which can therefore be added to measurement systems devoid of the displacement device 107 and of the sensing device 106, thus allows measuring the lateral displacement to perform the position reading of the fixed mark on the rail, with respect to the reference support.

In fact, the present invention provides transferring the reading point of the collimation plane laterally displaced, from the fixed marks on the rails to the graduated element 106b of the tiltable sensing device 106, positioned on the end of the module 200.

The rotation with straightening of the sensing device 106 allows intercepting the collimation plane 2 at the end of the measurement system 100, after the lateral displacement by an appropriate quantity by means of the displacement device 107 to align the collimation plane 2’ with the fixed mark present on the rails, allows measuring the lateral displacement corresponding to the longitudinal displacement of the rails.

In the preferred embodiment, the lateral displacement of the collimation plane 2 is made by means of an optical transformation device 107 such as a plane-parallel plate. For instance, by interposing and rotating the plane-parallel plate, the output laser beam is displaced and with the laser dot, visible from the railway platform, the original fixed marks on the rails are centered. Then, immediately downstream of the tool, the displaced laser beam is intercepted on the tilting millimetric reference or tilting electronic sensor. The zero of the tilting millimeter reference or electronic sensor is centered on the unique collimation plane generated by the original tool as it is forced by the particular coupling system to the original tool.

A first variant of the measurement system embodiment 100 is now described, wherein a different displacement device comprises a mechanical slide configured to translate in a calibrated manner the optical collimation device 102 in a direction perpendicular to the collimation plane 2. The translation is calibrated by means of a suitable sensing device configured to measure the lateral displacement of the mechanical slide, so as to allow the position reading of the fixed mark on the rail. In particular, said sensing device comprises an adjustment element, such as a graduated wheel or a graduated slider, configured to provide a calibrated measurement of the lateral displacement.

A second variant to the embodiment of the measurement system 100 is now described, wherein the sensing device is not provided with a movement hinge and with a graduated reference, but comprises an adjustment element, such as a graduated wheel or a graduated slider, configured to provide a calibrated measurement of the lateral displacement provided by the optical transformation device 107. For instance, by rotating the plane-parallel plate, which is located inside the tool, the line of sight of the collimation plane 2’ is translated and at this point a number is read on an eyepiece or on a graduated scale, corresponding to the lateral displacement.

A third variant of the embodiment of the measurement system 100 is now described, wherein the optical collimation device does not comprise a laser source, instead it comprises an optical tool, such as an optical telescope with reticle. Figure 11 illustrates a first embodiment of centering means 101 of the measurement system according to the present invention.

In general, the centering means 101 comprise a front abutment cylindrical clench 110, configured for a locking with centering on a lower generatrix line of a cylinder defined by the reference support or topographic peg 3. In particular, the cylindrical clench 110 comprises a substantially circular profile.

Figure 12 illustrates a second embodiment of centering means 101 of the measurement system according to the present invention.

The centering means 101 comprise a front abutment cylindrical clench 110b which comprises a sloping profile, in particular V-shaped, configured to cooperate with the reference support or topographic peg 3 at the lower generatrix line.

In both embodiments, the front abutment cylindrical clench 110 or 110b positions the measurement system 100 in a same spatial position, with respect to each topographic peg 3, since it tightens on the lower generatrix line of the cylinder constituted by the topographic peg 3 itself.

In particular, in both embodiments, the subsidiary reference element 103, mounted on the measurement system 100, prevents the transversal rotation of the unique collimation plane 2 on the topographic peg 3.

Further variants to the embodiment of the measurement system 100 are now briefly described, in possible implementations.

Preferably, a computerized reading device of the lateral displacement could be provided, by means of an electronic system with digital output, or by photographic recognition through an associated device, for instance a smartphone or tablet. Preferably, a GPS module associated with the computerized reading device could be provided, for instance the GPS already contained in the smartphone or tablet, which is configured to automatically detect a measurement position close to the rail.

Preferably, a computerized reading of the photographic image of the graduated element 106b could be provided. Preferably, direct computerized reading with electronic laser detection system could be provided. In general, optical-electronic and computer systems for the automatic acquisition and import of measured data could be provided.

Industrial applicability

In summary, the measurement system according to the present invention allows performing measurements in successive instants of time, by means of successive generations of collimation planes 2 and 2’ laterally displaced from each other, in order to detect and measure the longitudinal displacements and sliding of the rails 1, with respect to the fixed mark reported thereon. Said value of the longitudinal displacements and sliding is detected by means of the measurement of a lateral displacement with respect to a central zero defined by an original unique collimation plane 2, made to coincide with a reference support.

The measurement system according to the present invention therefore allows a single operator to perform all the longitudinal displacements and sliding measurement activities during operation - provided for by the regulations in force on the Long Welded Rail - with simultaneous automatic drafting of the appropriate control and certification modules.

Advantageously the present invention does not require the installation of dedicated fixed brackets. Moreover, advantageously, the present invention is fully operable from the outside of the tracks and therefore does not involve any interference with the overall outline generated by the train traffic. The present invention also allows the measurement data to be transferred and processed more effectively and to automatically draw up the certification of the thermal stress status of the Long Welded Rail, upon the detection, on specific verification tables. Considering the description herein reported, a skilled person can make further changes and variants in order to meet contingent and specific needs.

For instance, technical features described with reference to specific embodiments or variants, may be transferred and combined in further embodiments and variants where there is no technical prejudice.

The embodiments herein described are therefore to be intended as illustrative and non-limiting examples of the invention.

Claims

1. Measurement system for longitudinal displacements or sliding of at least one rail (1), in particular of a long welded rail (1), said measurement system comprising:

- centering means (101, 103) configured to anchor said measurement system to at least one reference support (3, 4);

- an optical collimation device (102) adapted to generate a collimation plane (2), unique with respect to said at least one reference support (3, 4) and projectable onto at least one web of said rail (1), to perform a position reading of at least one fixed mark on said rail (1);

- a displacement device (105) configured to provide a lateral displacement of said collimation plane (2’);

- a sensing device (106) configured to measure said lateral displacement for said position reading of said at least one fixed mark.

2. Measurement system according to claim 1, wherein said displacement device (105) comprises an optical transformation device

(107) comprising a plane-parallel plate, or one or more prisms optically equivalent to said plane-parallel plate.

3. Measurement system according to claim 2, wherein said optical transformation device (107) comprises a pair of surfaces (107a, 107b) respectively configured for a double refraction of said collimation plane (2, 2’), maintaining a direction of said collimation plane (2, 2’) and providing said lateral displacement in a parallel manner.

4. Measurement system according to claim 2 or 3, wherein said optical transformation device (107) further comprises a rotation element

(108) configured to rotate said optical transformation device (107) about an own vertical axis.

5. Measurement system according to any one of claims 2 to 4, wherein said optical transformation device (107) is separatable from said optical collimation device (102), to free an optical path and to generate a collimation plane (2) devoid of said lateral displacement.

6. Measurement system according to claim 1, wherein said displacement device (105) comprises a mechanical slide configured to translate said optical collimation device (102) in a calibrated manner in a direction perpendicular to said collimation plane (2).

7. Measurement system according to any one of claims 1 to 6, wherein said sensing device (106) comprises a graduated element (106b) configured to be selectively interposed on an optical path of said unique collimation plane (2’) downstream of said optical transformation device (107), for a measurement of said lateral displacement with respect to a predetermined center.

8. Measurement system according to claim 7, wherein said graduated element (106b) comprises at least one rotatable movement hinge (106a), to interpose in or to free said optical path, in particular being rotatable on an axis transversal to said collimation plane (2, 2’).

9. Measurement system according to any one of claims 1 to 6, wherein said sensing device (106) comprises an adjustment element, such as a graduated wheel or a graduated slider, configured to provide a calibrated measurement of said lateral displacement.

10. Measurement system according to any one of claims 1 to 9, wherein said at least one reference support (3, 4) comprises a topographic peg (3), in particular of the type already installed on railway lines to check the plano-altimetric status of said rail (1), and preferably further comprises a fixed reference (4), such as a hole (4), in particular made on a front surface of a pole associated with said topographic peg (3), to uniquely define said collimation plane (2).

11. Measurement system according to any one of claims 1 to 10, wherein said centering means (101, 103) comprise a front abutment cylindrical clench (110, 110b) configured for a locking with centering on a lower generatrix line of a cylinder defined by said at least one reference support (3, 4).

12. Measurement system according to claim 11, wherein said front abutment cylindrical clench (110b) comprises a sloping profile, in particular V-shaped, configured to cooperate with said at least one reference support (3, 4) at said lower generatrix line. 13. Measurement system according to claim 11 or 12, wherein said centering means (101, 103) further comprise a subsidiary reference element (103) configured to coincide with a fixed reference (4) associated with said reference support (3), said subsidiary reference element (103) being further adapted to constrain a rotation of said centering means (101, 103) with respect to said at least one reference support (3, 4).

14. Measurement system according to any one of claims 1 to 13, wherein said optical collimation device (102) comprises a laser-type light source, or an optical tool such as optical scope with reticle.

15. Measurement system according to any one of claims 1 to 14, further comprising a computerized reading device for reading said lateral displacement, and preferably further comprising a GPS module associated with said computerized reading device and configured to detect a measurement location at said at least one a rail.