WO2009030954A1

WO2009030954A1 - Track adjustment

Info

Publication number: WO2009030954A1
Application number: PCT/GB2008/050784
Authority: WO
Inventors: John Liddell
Original assignee: Jarvis Plc
Priority date: 2007-09-07
Filing date: 2008-09-04
Publication date: 2009-03-12
Also published as: GB0717403D0; GB2452619A; GB0816110D0

Abstract

A tamping machine (10) having a prism (20) receives a signal from a remote geostation (12). That signal determines the slewing of the track, the rail height adjustment of the track and the camber of the track.

Description

TRACK ADJUSTMENT

The present invention relates to a method of adjusting railway track, a railway track adjustment machine and a track adjustment system.

It is known to survey a length where railway track is to be deposited with a laser from a fixed, known position. The laser is emitted from a geostation or theodolite to a prism located at an elevated position on one side of the blade of a bulldozer which is used to level the ballast from which the track is to be layed.

The time taken for the laser beam to travel to the prism and then to be reflected back to arrive at the geostation determines the distance of the prism from the geostation.

The vertical angle of the prism from the light emission and light receiving part of the geostation determines the elevation of the prism. When viewed in plan, the angle of the light emitted from and received back at the geostation, relative to a vertical axis at the geostation determines the distance of the prism along a line.

Consequently the location of the prism in three dimensions is known.

In order to level ballast on a track the blade of the bulldozer can be moved up and down as the bulldozer advances, in accordance with the action of a hydraulic cylinder connecting the blade to the body of the bulldozer to ensure that the height of the blade and therefore the level of the ballast is as required at that particular location. In addition, a second hydraulic cylinder connecting the opposite side of the blade to that associated with the prism can be activated to rotate the advancing blade about an axis relative to the body of the bulldozer to incline the advancing blade to the horizontal to form a camber. In this respect, the geostation includes a memory facility that can emit a signal to a control of the bulldozer that the ballast, and therefore the blade, at that particular location is to be inclined. The line taken by the bulldozer is determined by markers placed in the ground at intervals.

Thus the bulldozer continually advances and, whilst doing so, planes the ballast to create the desired shape.

To adapt a standard manual bulldozer for use with the geostation, the only modification required is for the control for the hydraulic pistons to come from a signal derived from the geostation rather than the operator. Accordingly, the bulldozer equipment is largely unaltered: the blade is raised or lowered and tilted as the bulldozer scoops up the ballast.

It is also known to survey track, comprising rails held down on sleepers, using the geostation referred to above. Markers with prisms are held, manually, on the track at spaced positions and the fixed geostation, using the laser, determines the location of the rail at set, spaced positions. From that information, the desired location of the track and the inclination of the track is then calculated.

The track to be realigned is then marked at spaced intervals with instructions, for example "lift here 15 mm, move to the left 10 mm and incline one rail relative to the other by 5 mm", in order to get the track back in the correct position.

A tamping machine then moves along the rails of the track. This machine lifts the track by holding the rails at each side (or the sleepers) and then moves the track to the side by 5 mm and then pushes ballast under the sleepers at each side. The ballast is pushed by paddles that engage the ballast in the fore and aft direction of the rail to each side of the rail and to each side of the successive sleepers to shovel the ballast under the sleepers at each side. At the same time the ballast is vibrated to compact and settle the ballast. Vibration may be effected by vibrating the lifted track.

The tamping is effected until the desired movement has occurred. The tamping is effected whilst the machine is stationary .

Whilst tamping is well known, it suffers from inaccuracies both in the real movement that takes place at a particular location and in relation to where the track actually is in the sideways direction. The reasons for these inaccuracies are as follows.

The machine adjusts the movement of a rail in accordance with datum points in advance and trailing from the machine. Accordingly if the datum point in advance of the train is 3 mm higher than its optimum height, and if the trailing datum point is at its optimum height then the rail in the middle between those datum points will start at 1.5 mm higher than the operator thinks. Consequently the operator raises the rail by 15 mm to leave that rail 1.5 mm higher than the optimum point. Similar problems arise in relation to the sideways shifting of the rails where datum points are taken in advance and trailing from the location where tamping occurs. Such tamping machines are well known.

It is an object of the present invention to attempt to overcome at least one of the above or other disadvantages.

The present invention is defined in the appended claims and elsewhere in this specification.

With the present invention, large portions of the tamping machines previously available have been removed. This results in significant advantages not just in relation to the increased accuracy of the track realignment but also in the removal of complicated mechanisms that effected the adjustment between the datum points. Such mechanisms frequently break down or require regular maintenance. In addition, one problem addressed by the present invention is how to adjust the position of track that may already be laid in place or that may be being added to a new location rather than the removal or levelling of a surface of loose stones.

The present invention can be carried into practice in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawings, in which:-

Figure 1 is a schematic perspective view of a tamping machine 10 and a geostation 12; Figure 2 is a schematic side view of the tamping machine 10;

Figures 3 and 4 are end and side views of the lifting station 14;

Figure 5 is a schematic perspective view of the slewing station 16;

Figure 6 is a schematic end view of a shovel station of the machine, and

Figure 7 is a schematic side view of an alternative tamping machine 110.

Figure 8 is a pictorial view of a geostation communicating to a control and reflecting prism of a tamping machine.

Figure 1 shows the tamping machine 10 in communication with the geostation 12. That communication is effected by a laser beam being emitted from the geostation towards the machine and then being reflected back from a prism 20 on the machine.

The angle 22 between a dotted datum line 24 and the laser line 18, which angle is in the horizontal plane, locates the position of the prism along track 26. The angle 28 between the line 20 and the dotted datum line 30, which angle extends vertically, shows the difference between the desired height of the line 32 and the actual height. The time taken for the laser 18 to be emitted from and returned to the geostation 12 indicates the actual position of the rail 32. Accordingly, the geostation is able to determine exactly where the prism is in relation to it.

The geostation 12 is fixed in position for a given length of track such as 300 m, for instance. The exact point of the geostation and its height is known. This may be by locating the geostation using precision equipment such as a GPS system. Alternatively, the geostation may be used to profile the area such that, although the exact global position of the geostation is unknown, the exact position of the geostation in relation to fixed objects, such as a bridge or platform, is known.

The desired profile of the track is programmed into the geostation. For instance, the geostation is programmed with information detailing the exact height, position and tilt (height difference between the two rails) at incremental positions along the track or along the entire length of the section. Accordingly, as the machine travels along the track, or at specific points along the track, the geostation locates the prism, as described below, and thus determines exactly where the track is. It can then calculate the required height difference and slew required to adjust the track such that it moves to the correct position. The adjustments can be communicated to the tamping machine in order to correct the profile of the track. The laser can track the movement of the rail by following the prism and, if necessary, confirm to the tamping machine that the rail is in the correct position before the tamping machine moves to the next position. Accordingly the geostation will know what the profile of the track should be and how close to a bridge or station platform that profile of track should be.

The prism 20 is mounted on a pole 34 and the pole 34 is connected to the machine in a manner whereby it follows the position of the rail 32 such as by a roller 36 riding on the rail .

The tamping machine operates as follows.

First the laser from the geostation 12 locates the prism 20 in a well known manner, such as by picking up reflected light from coloured LED's located just beneath the prism. Information in the geostation is then transmitted, for instance by a Radio Frequency Link, to a control 38 in the machine informing that control of the adjustments that are required such as: raise rail 32 by 18 mm, bring rail 32 to the right with respect to the direction of travel of the machine and raise the other rail 40 by 3 mm with respect to the position of rail 32.

The operator then actuates the lifting station 14 shown in Figures 3 and 4 to cause arms 42 to pivot inwardly about axes 44 to locate shoes 46 under rails 32 and 28. The arms 42 and thereby the rails are then raised to a height determined by the signal received from the geostation such as 18 mm at one side, which height may be different at each side. The arms 42 are powered by actuating valves that power hydraulic pistons in a manner well known in tamping machines.

Next the slewing station 16 shown in Figure 5 is activated. Flanged wheels 48 that ride on the rails are caused to move the rails to the right or left in dependence upon the actuation of valves of a hydraulic cylinder 50 with the flanges on those wheels moving the track to the right or left to an amount dictated by the control 38. Such slewing movement is well known in tamping machines.

Subsequently the shovel station 52 is activated. This causes spades 54 to pivot and reciprocate about axes 56 parallel to the longitudinal extent of the sleepers 58 to squeeze ballast 60 inwardly at either end region of the sleepers. The duration or the amount of ballast shovelled under the sleepers may be determined by the control 36. The reciprocation of the spades is effected by actuating valves that cause hydraulic pistons to reciprocate the spades in a manner well known in tamping machines.

The above sequence of lift, slew and shovel may be altered or some actions may occur simultaneously. The control may automatically initiate at least one of these actions and, alternatively or additionally may end these actions. Alternatively or additionally, the operator may initiate at least one of these actions. Alternatively or additionally the operator may end at least one of these actions.

Whilst the shovelling station is being operated the rail lifting station 14 or the shovelling station 16 may be vibrated to settle or compact the ballast.

The amount that each rail has been raised and alternatively or additionally, the slew may be fed back to the control 36 which may then determine that the machine can move again to the next position or which may determine the speed that the machine advances along the rails as the track adjustment takes place. Alternatively, the geostation 12 may communicate to the control 34 feedback information on the position of the rail so that control 6 knows when the desired position has been reached.

The tamping machine 110 shown in Figure 7 is the same as that of Figure 2 with the exception that the prism, shovel station, lifting station and slewing station are all mounted on a carriage 160 that can slide along a rail 165, which rail is constrained to move with the machine. Consequently the machine can continually advance with tamping taking place along a stationary carriage. When tamping is complete, the carriage is moved along the rail 162 to the front of the machine where tamping is effected at the next required sleeper with the machine slowly advancing .

In either embodiment, the speed of tamping or the speed of the machine or the end of tamping at a particular location may be determined by a signal at the control station which is received from the geostation indicating that the lift or the slew or the slant of the track or any combination thereof is complete. In addition the speed of any or all of the tamping operations may be reduced from an initial speed, for instance as the desired location is reached and this speed reduction may be effected automatically.

Alternatively, the operator may determine when the required adjustment has taken place before moving the machine to the next location or in controlling the rate of advancement as adjustment takes place. Whilst the control 36 may or may not initiate the actuation of at least one station and may even end that actuation, such as by controlling the valves at that station, it may be possible for the operator to actuate or end or control at least one of the stations.

For instance, the operator may reduce the rate of lift of at least one rail or slew either throughout that movement or towards an end of that movement. This may be because different track conditions require different responses for the same degree of required adjustment. Thus if the sleepers are lightweight metal sleepers rather than heavy reinforced concrete less lifting or slewing force is required and the force required to move the track or the rate of movement may be required to be less. Alternatively or additionally, information about the sleepers may be programmed into the control whereby the above factors are taken into account in the automatic adjustment.

In addition, whilst it might appear that the rail should be slewed by 10 mm to correct a misalignment of 10 mm that is not often the case. There is some spring in the rails that will tend to slew the rails in a particular direction. This likely spring may be programmed into the control which may decide (or, alternatively or additionally an operator may decide) to increase or decrease the amount of slew to allow for that spring force whereby the track is over or under slewed from the degree of slew received from the geostation. Lightweight, metal sleepers tend to have more spring than rails that are weighed down by heavy concrete sleepers. It can sometimes occur that one rail is persistently 3 mm lower than the other rail and the required height after the indicated degree of tamping has occurred. In this instance the operator can squeeze more ballast under the sleeper at that side than is indicated by or that would otherwise be automatically caused by the control 38. In addition, it may be that the control 38 indicates that each sleeper should have ballast squeezed under it, it is possible that every other sleeper may have ballast squeezed or even third or fourth sleepers, and the operator may be able to override the control 38 if they think more or less sleepers are required to have ballast squeezed under them. Alternatively, or additionally the control may be able to make this judgement from the track profile that is programmed into it.

The geostation may be programmed with a track profile that is required. Thus when the machine is at a particular location, the geostation may inform the control 36 that, at that location, the rail 32 should be 3 mm higher than the rail 38.

The condition of a track may be determined in various ways. One way is to take manual readings at spaced locations along one rail. This may be an operator taking up these positions and standing at the locations with a signal from an operator prism being returned to the operator. Another may be to roll a vehicle such as, for instance, the machine 10, along the track with a prism on the machine following one rail reflecting a laser to the geostation either continuously, as the prism moves or at spaced locations. Once the condition of the track is known or, alternatively or additionally, once it is known where a track is required, the desired track profile can be determined and programmed into the geostation, for instance. Thus the correct condition of a track can be used when determining the profile.

The track profile can be programmed into the geostation or the control 36. The control 36 may effect the actuation of any or all of the speed of the machine advancement, the lift, the slew, the slant and shovelling of material and, alternatively or additionally, may give an end signal to any or all of those events. Control may be effected by opening or closing or all of those events. Control may be effected by opening or closing valves. The control may also be able to alter the speed or change the speed such as to reduce the speed of any of the rate of advancement of the machine, the shovelling, lifting or slewing or slanting or any combination thereof.

Referring to Figure 8, the geostation 12 emits the laser beam 18 to detect the exact position of the prism 20 as herein described. The location of the prism 20 is fixed with respect to the roller 35 that rides on the rail 32 due to the prism 20 being mounted on the pole 34 that extends from an arm 35. The arm 35 is fixed to the roller's support. The arm 35 and pole 34 are kept as short as possible in order to reduce inaccuracies. For example, if the pole 34 or arm 35 are too long such that they flex, the location of the rail is corrupted because the relationship between the location of the prism and the location of the bottom of the roller (i.e. the top of the rail) would change. Due to the direct relationship between the prism and the roller 36, the location of the nearside rail (relative to the location of the geostation 12) can be set as herein described. However, since the geostation is located at the side of the track and since the nearside rail and far side rail can move independently, the location of the far side rail cannot be recorded/found based on the location of the prism alone. Moreover, it is not possible to obtain a line of sight between the geostation and a position close to a roller (not shown in Figure 8) that rides on the far side track. Accordingly, in order to avoid having a second geostation on the other side of the track or a prism mounted on a long pole above the tamper, a tilt sensor 70 is mounted on the arm 35.

The rollers on each side of the tamper are a fixed distance apart and rotate about a common axis. The arm 35 is arranged to extend parallel to the common axis. By monitoring the degree of tilt of the arm 35, the exact position of the roller on the far side can be determined from the location of the prism 36. In this way the location of the far side rail can be found and corrected by the tamping machine as herein described.

After a section of track has been adjusted as described above, the track can be surveyed to determine the correct profile. This may be done manually at spaced locations.

Alternatively or additionally it may be effected by rolling a device, such as the machine 10, along the rails with a prism reflecting a laser back to the geostation to indicate the profile. Whilst the specific embodiment has been described in relation to adjusting already laid track the invention is equally applicable to relaying track or in laying new track on a new base.

With the track adjustment according to the present invention, an extremely accurate profile of the track can be achieved in a single pass of the machine. This compares to the prior tamping machine where, because of the datum points that result in errors inevitably occurring, several passes may be needed to reduce these errors .

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method of adjusting railway track comprising emitting a laser from a first location to one side of a path that the track follows towards a receiver located in the region of the path where adjustment is required, the laser determining the location of the receiver along the track as a result of the line of the laser from the first location to the receiver and adjusting the rail track, if necessary, from an actual position to a desired position by generating at least one signal as a result of the emitted laser and adjusting at least one of the height of the track, the sideways movement of the track or the camber of the track as a result of at least one signal.

2. The method as claimed in Claim 1 in which the laser receiver comprises a laser reflector and a side signal is generated, if necessary, dependent upon the time taken for the laser to travel from the first location to the reflector and then back to the first location.

3. The method as claimed in Claim 2 comprising moving the track to one side or the other of the current position as a result of the side signal.

4. The method as claimed in Claim 3 comprising raising and moving the track to one side or the other.

5. The method as claimed in Claim 3 or 4 comprising automatically moving the track to one side or the other as a result of the side signal.

6. The method as claimed in Claim 5 comprising automatically actuating at least one valve of a side adjustment power system to move the track.

7. The method as claimed in any of Claims 3 to 7 comprising moving the track to one side or the other to a location different from the final desired location of the track with the track subsequently flexing back towards the desired position.

8. The method as claimed in any preceding claim comprising generating a height signal, if necessary, and raising at least one rail and then lowering the track to the desired height as a result of the height signal.

9. The method as claimed in Claim 8 comprising the height signal automatically causing the height adjustment.

10. The method as claimed in Claim 9 comprising automatically causing the height adjustment by actuating at least one valve of a height adjustment power system.

11. The method as claimed in any preceding claim in which the track includes two rails the method comprising, if necessary, adjusting the height of one rail relative to the other as a result of a generated camber adjustment signal .

12. The method as claimed in Claim 11 in which the height of one rail relative to the other is automatically adjusted as a result of the camber adjustment signal.

13. The method as claimed in Claim 12 in which the camber is adjusted by actuating at least one valve of a camber adjustment power system.

14. The method as claimed in any preceding claim comprising storing the information about the desired profile of the track at the first location and using information derived from the laser and receiver to effect the adjustment.

15. The method as claimed in Claim 15 comprising automatically decreasing the speed of adjustment as the optimum position of the track is being approached.

16. The method as claimed in Claim 14 or 15 comprising effecting the adjustment at one location of the track with feedback on the adjustment that has been made at the first location being used to indicate when advancement along the track may be made to effect adjustment at a second location.

17. The method as claimed in Claim 16 in which the advancement is made automatically as a result of the feedback .

18. The method as claimed in any preceding claim comprising determining the actual profile of the track at the first location before commencing to adjust the position of the track.

19. The method as claimed in Claim 1 comprising moving a machine along the track with information received at the first location from a laser emitted from the first location to a receiver on the machine being used to determine the actual profile of the track.

20. The method as claimed in any preceding claim comprising determining the profile of the track at the first location after adjustment of a length of track has been effected by a laser being emitted from the first location to a receiver in the region of the track.

21. The method as claimed in Claim 20 comprising noting differences in the actual position of the length of track from the adjustments that have been made to the length of the track.

22. The method as claimed in Claim 20 or 21 comprising moving a machine along the track with information received at the first location from a laser emitted from the first location to a receiver on the machine being used to determine the profile of the track after adjustment.

23. The method as claimed in Claim 22 or 19 in which the machine comprises the same vehicle that effects the adjustment of the track.

24. A railway track adjustment machine including a laser receiver, the receiver being arranged, in use, to receive a laser from a first location located to one side of the path of the track that is to be adjusted which laser is arranged to generate at least one signal from a control of the machine to effect adjustment, if necessary, of at least one of the height machine adjustment apparatus of the track, the machine sideways movement apparatus of the track or the machine camber adjustment apparatus of the track .

25. The machine as claimed in Claim 24 including a laser reflector arranged, in use, to reflect a laser emitted from the first location back to the first location whereby the distance of the reflector from the first location is able to be determined.

26. The machine as claimed in Claim 24 or 25 in which the machine includes power means arranged, in use, to reposition the track as a result of the signal from the control .

27. The machine as claimed in Claim 26 in which the signal is arranged to automatically cause the repositioning of the track as a result of the generated signal.

28. The machine as claimed in any of Claims 24 to 27 in which the control is arranged to indicate when the required adjustment has been made at one location of the track and when the machine may advance along the track.

29. The machine as claimed in Claim 28 in which the control is arranged, in use, to automatically advance the machine to a second location along the path of the track when the required adjustment has been made.

30. The machine as claimed in any of Claims 24 to 29 when used in a method as claimed in any of Claims 1 to 23.

31. A track adjustment system including a machine as claimed in any of Claims 24 to 30 and a laser station the laser station being arranged, in use, to be at a first location located to one side of the path of the track, the laser station being arranged to determine the adjustment effected by the machine.

32. The system as claimed in Claim 31 in which the laser station is arranged to determine when the machine is to advance to effect adjustment at a different location of the track.

33. The system as claimed in Claim 31 or 32 when using a railway track adjustment system as claimed in any of Claims 24 to 30.

34. A method of determining the location of two rails of a railway track, the method comprising: locating a station to one side of the railway track; moving a machine having a first follower that rides on a near side rail and a second follower that rides on a far side rail along the railway track; determining the location of a receiver mounted on the medium at specific positions along the track by emitting a laser beam from the station, the laser beam reflecting from the receiver and being received by the station, wherein the location of the receiver is fixed in relation to the first roller; and determining the independent location of both the near side rail and the far side rail.

35. The method as claimed in claim 11 or claim 35 wherein the location of a near side rail is calculated from a fixed offset from the determined location of the receiver and wherein the location of a far side rail is calculated using the determined location of the receiver and a tilt factor determined from a tilt measurement means.

36. The method as claimed in claim 34 or 35, wherein the method comprises using the determined locations of the near side and far side rail to adjust the railway track.

37. The method as claimed in claim 36 wherein the method comprises a method of adjusting railway track as claimed in any of claims 1 to 23.

38. The method as claimed in any of claims 34 to 37 wherein the method comprises using a machine as claimed in any of claims 24 to 31.