Rail coach height tool

Abstract

A rail coach height tool 20 and method of use. The tool comprises a support body 21 adapted to be retained against at least one wall or the floor 24a, 24b, 24c, of an inspection pit 25 and at least on

Description

The present invention relates to a rail coach height tool and a method of supporting a rail coach over an inspection pit, in particular method of carrying out the maintenance of a rail coach supported over an inspection pit. Rolling stock maintenance is a major factor in ensuring the safe running of a railway. Such maintenance can vary from replacement and repair of parts, such as compressors, air conditioning units and motors, to the upkeep of bogies and wheels. Train wheels are machined from a single casting, and provided with a profiled circumference that helps to keep the wheel on the rail. This profile has a tread that forms the contact surface of the wheel on the rail, and a flange, a projection that runs inside the rail to prevent the wheel from slipping off. The tread is commonly angled with respect to the wheel plate as a conical wheel shape provides adhesion during cornering. During use, both the tread and the flange wear due to friction with the rails, flattening the profile until the wheel becomes unsafe due to decreased adhesion with the rails. In order to prevent excessive wheel wear, damage and derailments, the profile of the wheels is inspected regularly, and when a designated wear point is reached, re-profiled using a wheel lathe. The wheel lathe grinds down the contact surface of the wheel until the profile is restored, a process that can be repeated a number of times over the lifetime of the wheel until a minimum thickness of the tread is reached, and the wheel is taken out of service. Since the wheels support a rail coach or locomotive on the rails, accessing them for maintenance and lathing is a challenge. This challenge may be approached in a number of ways: either by fitting a wheel lathe into an inspection pit under a maintenance track and reprofiling a wheelset at a time (Underfloor Wheel Lathes or UFWL); or by lifting the coach / locomotive and removing the wheelsets for reprofiling away from the inspection pit. Lifting the coach / locomotive requires jacks positioned either within or alongside the inspection pit. Pitside jacks require a significant amount of space around the inspection pit, which may not be available, particularly in older maintenance depots. In addition, they can present a hazard to maintenance staff as they extend a significant distance from the edge of the pit and may be a cause of trips as people walk past. Jacks positioned within the pit are smaller and more portable, and can be used even when the amount of space around the inspection pit is limited. Figure 1 is a photograph of a conventional jack in an inspection pit. The inspection pit 1 is provided with rails 2a, 2b on which a rail coach or locomotive can sit in order for maintenance tasks to be carried out. Two conventional jacks 3 are shown sitting within the inspection pit 1. Each jack 3 comprises a pivot arm 4 sat on a base 5. The pivot arm 4 is provided with a rotatable support 6 at each end, with an adjustable contact plate 7 on the distal end of the rotatable supports 6. Each adjustable contact plate 7 is moveable by means of a wheel 8, which when rotated moves the adjustable contact plate 7 on a screw thread arrangement. In order to raise a rail coach, two technicians need to enter the inspection pit 1, and initially rotate the pivot arm 4 by means of the handles 9 along each side of the pivot arm 4. Once the pivot arm 4 is rotated to be perpendicular to the walls of the inspection pit 1, the rotatable supports 6 are rotated 90° to a vertical position and locked in place using locking pins 10. The wheels 8 are then turned, which extends the screw thread arrangement, raising the adjustable contact plates 7 until they contact the jacking point on the underside of the rail coach. Since the jack 3 itself is capable only of holding the weight of the rail coach and not lifting it, the process requires the lifting of the rail coach using its secondary suspension system. The secondary suspension system comprises a number of airbags forming an airspring arrangement in addition to the main suspension system springs. To lift the rail carriage, these airbags are first overinflated to raise the height of the rail coach before the jack 3 is positioned underneath the jacking points within the inspection pit 1. The jack 3 is then used to hold the rail coach in this elevated position for maintenance to take place. When the required maintenance is completed, the jack 3 is lowered away from the underside of the rail coach and the airbags are deflated to their usual in-service pressure and volume, restoring the secondary suspension system to its normal status. However, because the suspension has been altered, the rail coach must be run on a track for a minimum of twenty minutes to ensure that all of the suspension system has returned to its appropriate level. Whilst this jacking process offers a workable solution to maintenance in rail depots where there is insufficient space around the inspection pit for pitside jacks and where UFWL systems are not fitted, it does come with a number of disadvantages. The jack 3 requires two technicians for use due to its weight, since the weight of the jack 3 in total is 275kg, with the pivot arm alone weighing 55kg. Not only does this create a risk of manual handling issues due to weight, but both technicians must fit within the confined space of the inspection pit 1. The weight of the jack 3 combined with the manual use element increases the risk that any injuries during use will be muscular or crushing injuries, which may be serious in nature. The lifting and lowering process itself is uncontrolled, since this is reliant on the overfilling and deflating of the secondary suspension system airbags, which in itself constitutes a health and safety issue. The suspension system becomes subject to hysteresis from the use of the airbags, as the springs of the main suspension system are stretched and compressed beyond their normal use range. Given the injury risk and the time consuming nature of the overall process, technicians are often reluctant to use the jack 3, which impacts on productivity as well as physical and mental health and wellbeing. It would therefore be highly desirable to find an alternative solution that enables technicians to work in a safer environment where the problems above are mitigated. The present invention aims to address these issues by providing a rail coach height tool, comprising: a support body adapted to be retained against at least one wall of an inspection pit, the inspection pit being an open three-sided elongate channel over which a rail coach is positioned; at least one powered lifting mechanism installed on the support body; and a height-adjustable platform mounted on the at least one powered lifting mechanism and adapted to align with a secondary suspension system present on the underside of a rail coach, wherein at least two compression pins are provided on the height-adjustable platform and adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach.. The combination of a powered lifting mechanism and compression pins adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach removes the manual component from the lifting process completely. The support body may be adapted to be retained between two of the sides of the inspection pit. In this situation, the support body may be further adapted to be engageable with, and movable along, the sides of the inspection pit. Alternatively, the support body may be adapted to rest on, and be moveable along, a side of the inspection pit opposite its opening. In this situation, preferably, the support body is mounted on wheels. Preferably, the support body and the height-adjustable platform extend across the width of the inspection pit. Preferably, the powered lifting mechanism comprises actuation means connected to a control located remotely from the rail coach height tool. Preferably, the at least one powered lifting mechanism is hydraulic. Preferably a remotely controlled compressed air supply is connected to the powered lifting mechanism. The height-adjustable platform may be further adapted to hold the weight of the rail coach. The present invention also provides a method of supporting a rail coach over an inspection pit, comprising: positioning a rail coach height tool as described above within an inspection pit underneath a secondary suspension system of the rail coach and securing the rail coach height tool in the position; isolating the compressors on the secondary suspension system; raising the height-adjustable platform until the at least two compression pins each contact an airbag in the secondary suspension system of the rail coach; and raising the height-adjustable platform and compressing the airbags until the rail coach rests on its primary suspension system alone. The present invention also provides method of carrying out the maintenance of a rail coach supported over an inspection pit, comprising: positioning a rail coach height tool as described above within an inspection pit underneath a secondary suspension system of the rail coach and securing the rail coach height tool in the position; isolating the compressors on the secondary suspension system; raising the height-adjustable platform until the at least two compression pins each contact an airbag in the secondary suspension system of the rail coach; raising the height-adjustable platform and compressing the airbags until the rail coach rests on its primary suspension system alone; carrying out maintenance tasks; and when the maintenance tasks are complete, lowering the height-adjustable platform, decompressing the airbags and removing the support from the rail coach. The present invention will now be described by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a photograph of a conventional jack in an inspection pit; Figure 2 is a schematic side view of a rail coach height tool in accordance with embodiments of the present invention; Figure 3 is a schematic side view of a rail coach height tool in accordance with embodiments of the present invention; Figure 4 is a schematic perspective view of an alternative height-adjustable platform for use with embodiments of the present invention; Figure 5 is a flowchart outlining a method of supporting a rail coach over an inspection pit in accordance with embodiments of the present invention; and Figure 6 is a flowchart outlining a method of carrying out the maintenance of a rail coach supported over an inspection pit. The embodiments of the present invention take the approach that a rail coach height tool can utilise a hydraulic approach to lifting the rail coach rather than relying on the secondary suspension system, which in turn means that the controls of the tool can be handled from outside of the inspection pit. In the following description, the embodiments of the present invention are described in relation to a rail coach, however it should be understood that the rail coach height tool may be employed in relation to any rail vehicle, such as a locomotive, goods wagon or light rail transit (subway, underground, tram) vehicles. The embodiments of the present invention, described in more detail below, utilise a rail coach height tool. The tool comprises a support body adapted to be retained against at least one wall of an inspection pit, the inspection pit being an open three-sided elongate channel over which a rail coach is positioned. At least one powered lifting mechanism, such as a piston, is installed on the support body. A height-adjustable platform is mounted on the at least one powered lifting mechanism and adapted to align with a secondary suspension system present on the underside of a rail coach. At least two compression pins are provided on the height-adjustable platform and adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach. The secondary suspension system comprises the airbags and compressors that are used to maintain their pressure during use, and these are isolated before the airbags are compressed. The methods of using such a rail coach height tool are also discussed and described below. Figure 2 is a schematic side view of a rail coach height tool in accordance with embodiments of the present invention. The rail coach height tool 20 comprises three main elements: a support body 21, at least one powered lifting mechanism 22 and a height-ad-justable platform 23. The support body 21 is adapted to be retained against at least one wall 24a, b, c of an inspection pit 25, where the inspection pit is an open three-sided elongate channel over which a rail coach is positioned. At least one powered lifting mechanism 22 is installed on the support body 21. In the example illustrated in Figure 2, there are two powered lifting mechanisms 26a, 26b, in the form of pistons. However, it should be understood that the invention is not limited to the use of two powered lifting mechanisms, but that one, three or more may be used if required. The height-adjustable platform 23 is mounted on the at least one powered lifting mechanism 22 and adapted to align with a secondary suspension system present on the underside of a rail coach. At least two compression pins 27 are provided on the height-adjustable platform 23 and adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach. In the illustrated example, the height-adjustable platform 23 is a beam, and a compression pin 27 is provided on each distal end of the beam. By compressing the airbags, the air is let out of the secondary suspension system such that the airbags deflate, leaving the rail coach supported on the primary suspension system alone. This ensures that the height of the rail coach remains constant. Within the inspection pit 25, each side wall 24a, 24c is provided with a pair of ledges 28a, 28b, 29a 29b separated from each other to form a channel 30a, 30b that runs horizontally along the side walls 24a, 24c, parallel with the open surface of the inspection pit 25. The support body 21 is adapted to be retained between two of the sides 24a, 24c of the inspection pit 25, as well as being engageable with, and movable along, the sides of the inspection pit 25. This is achieved in this example by the use of wheels 31 that engage with the ledges 28a, 28b, 29a 29b. To ensure that the rail coach height tool 20 is stable within the inspection pit 25, both the support body 21 and the height-adjustable platform 23 extend across the width of the inspection pit 25. As further illustrated in Figure 4 below, the beam forming the height-adjustable platform 23 may extend beyond the width of the inspection pit 25 when in use. The powered lifting mechanism 22 comprises actuation means 32 connected to a control 33 located remotely from the rail coach height tool. For hydraulic lifting means 22, such as the pistons illustrated in Figure 2, a nozzle 34 is provided to connect the tubing required to ensure that the compressed air feed serves the pistons at one end, and may be located away from the inspection pit 25 to enable remote control of the height-adjustable platform by a technician located outside of the inspection pit 25. However, other powered lifting mechanisms may be used, such as an electric motor powered screw thread arrangement, which may also be operated remotely by means of a wired or wireless remote control handset. Figure 3 is a schematic side view of a rail coach height tool in accordance with embodiments of the present invention. The rail coach height tool 40 comprises three main elements: a support body 41, at least one powered lifting mechanism 42 and a height-ad-justable platform 43. The support body 41 is adapted to be retained against at least one wall 44a, b, c of an inspection pit 45, where the inspection pit is an open three-sided elongate channel over which a rail coach is positioned. At least one powered lifting mechanism 42 is installed on the support body 41. In the example illustrated in Figure 3, there are again two powered lifting mechanisms 46a, 46b, in the form of pistons. However, it should be understood that the invention is not limited to the use of two powered lifting mechanisms, but that one, three or more may be used if required. The height-adjustable platform 43 is mounted on the at least one powered lifting mechanism 42 and adapted to align with a secondary suspension system present on the underside of a rail coach. At least two compression pins 47 are provided on the height-adjustable platform 43 and adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach. In the illustrated example, the height-adjustable platform 43 is a beam, and a compression pin 47 is provided on each distal end of the beam. By compressing the airbags, the air is let out of the secondary suspension system such that the airbags deflate, leaving the rail coach supported on the primary suspension system alone. This ensures that the height of the rail coach remains constant. The powered lifting mechanism 42 comprises actuation means 48 connected to a control 49 located remotely from the rail coach height tool. For hydraulic lifting means 42, such as the pistons illustrated in Figure 3, a nozzle 50 is provided to connect the tubing required to ensure that the compressed air feed serves the pistons at one end, and may be located away from the inspection pit 45 to enable remote control of the height-adjustable platform by a technician located outside of the inspection pit 45. However, other powered lifting mechanisms may be used, such as an electric motor powered screw thread arrangement, which may also be operated remotely by means of a wired or wireless remote control handset. Unlike the embodiment of Figure 2, the rail coach height tool in Figure 3 is not retained between two side walls 44a, 44c of the inspection pit 45. Instead, the support body 41 is mounted on wheels 51 that run along the side 44b forming the floor of the inspection pit 45. This enables the rail coach height tool 40 to be used in inspection pits 45 where the side wall 44a, 44b ledges are not available. Figure 4 is a schematic perspective view of an alternative height-adjustable platform for use with embodiments of the present invention. In each of Figures 2 and 3, the height-adjustable platform 23, 43 is a solid beam that extends across the width of the inspection pit 25,45. However, there may be situations where it is desirable for this beam to be adjustable in length. Figure 4 illustrates a beam 60 having a central, hollow portion 61 with a square cross-section, and two extendable arms 62, 63 that are dimensioned and sized to form a sliding fit within the central hollow portion 41 of the beam 61. Each of the arms 62, 63 supports the compression pins 64, 65 required to compress the airbags of the secondary suspension system. The use of the extendable arms 62, 63 enables the beam 60 to be used in situations where it is necessary to have a smaller width height-adjustable platform 23, 43 to install the rail coach height tool 20, 40, in an inspection pit 25,45. Once positioned within the inspection pit 25, 45, the extendable arms 52, 53 may be slid out from the central, hollow section 61 and once the compression pins 64 and 65 are in the correct position, locked in place by means of locking pins 66, 67. This provides greater flexibility in terms of the installation requirements and inspection pit configuration than with conventional jacks. In each example above, the rail coach height tool 20, 40 is made from a cast metal or metallic alloy, such as steel, which may be subsequently machined and painted. The support body 21, 41 may be formed from a kit of components bolted and / or welded together, or cast as a single piece, depending on the final use of the rail coach height tool 20, 40. The nozzle 36, 50 is also formed from a cast and machined metal or metallic alloy, and may be provided with a resilient seal if required. The wheels 31, 51 are made from a polymeric material such as rubber, nylon or polyurethane, and may be provided with a solid core, for example, using cast iron, aluminium or nylon (in the case of polyurethane). Each wheel may also be provided with a brake mechanism if desired. Figure 5 is a flowchart outlining a method of supporting a rail coach over an inspection pit in accordance with embodiments of the present invention. The method 700 comprises, at step 702, positioning the rail coach height tool 20, 40 as described above with reference to Figures 2, 3 and 4 within an inspection pit 25, 45 underneath a secondary suspension system of the rail coach. This is done by aligning the rail coach height tool 20, 40 with the airbags of the secondary suspension system of the rail coach. Once positioned, at step 704, the rail coach height tool 20, 40 is secured the position, for example, by using the brake mechanism on the wheels 31, 51. Next, at step 706, the compressors of the secondary suspension system are isolated. This ensures that the airbags remain compressed during the use of the rail coach height tool. At step 708, the height-adjustable platform 23,43 is raised until the at least two compression pins 28,48 each contact the valve of an airbag in the secondary suspension system of the rail coach. At step 710, raising of the height-adjustable platform 23, 43 continues, along with the and compressing the airbags until the rail coach rests on its primary suspension system alone. It may be desirable, depending upon the maintenance being carried out, for the height-adjustable platform to continue to be raised such that the weight of the rail coach comes to rest on it. This effectively jacks the rail coach up, taking the weight in preference to the primary suspension system, enabling work to be carried out on components not in reach while the rail coach is resting on the primary suspension system. Figure 6 is a flowchart outlining a method of carrying out the maintenance of a rail coach supported over an inspection pit. The method 800 comprises, at step 802, positioning the rail coach height tool 20, 40 as described above with reference to Figures 2, 3 and 4 within an inspection pit 25, 45 underneath a secondary suspension system of the rail coach. This is done by aligning the rail coach height tool 20, 40 with the airbags of the secondary suspension system of the rail coach. Once in position, at step 804, the rail coach height tool 20, 40 is secured the position, for example, by using the brake mechanism on the wheels 31, 51. Next, at step 806, the compressors of the secondary suspension system are isolated. This ensures that the airbags remain compressed during the use of the rail coach height tool. At step 808, the height-adjustable platform 23, 43 is raised until the at least two compression pins 28, 48 each contact a valve on an airbag in the secondary suspension system of the rail coach. To maintain the decompression of the airbags, the compressors of the secondary suspension system are isolated. At step 810, raising of the height-adjustable platform 23,43 continues, along with the compressing the airbags until the rail coach rests on its primary suspension system alone. At this point, the rail coach is supported by the height-adjustable platform 23, 43, and, at step 812, maintenance tasks can be carried out. These may include, but are not limited to, wheelset removal for wheel lathing, thus negating the issues found when using conventional jacks in a process for train wheel maintenance. Once the wheels have been ground, their diameter is reduced, requiring the placing of shims into the bogie to take into account this change in wheel size. This is achieved easily whilst the rail coach rests on the primary suspension system. Alternatively, it may be desirable, depending upon the maintenance being carried out, for the height-adjustable platform to continue to be raised such that the weight of the rail coach comes to rest on it. This effectively jacks the rail coach up, taking the weight in preference to the primary suspension system, enabling work to be carried out on components not in reach while the rail coach is resting on the primary suspension system. Finally, at step 814, when the maintenance tasks are complete, the height-ad-justable platform 23, 43 is lowered, which is done by releasing the pistons in the powered lifting mechanism 22, 42 and turning on the compressors in the secondary suspension system to refill the airbags. In both Figure 5 and Figure 6 the methods in accordance with the embodiments of the present invention are illustrated with the isolation step 706, 806 occurring after the rail coach height tool 20, 40 is positioned and secured. However, it is also within the scope of the present invention that these steps are reversed, and the compressor isolation step 706, 806 occurs before the positioning and securing step 702, 704, 802, 804. The rail coach height tool 20, 40 and method of its use in accordance with the embodiments of the present invention mitigates completely any safety risks associated with 5 conventional jacks since there is no need to stand in the inspection pit below a rail coach in situ. The use of hydraulic or screw thread arrangement lifting results in complete and accurate control over the lifting and lowering of the height-adjustable platform 23, 43. Since the airbags in the secondary suspension system are compressed and the height of the rail coach is not affected, the overall suspension system remains unchanged, remov- 10 ing hysteresis issues and the need for any form of reset by running the rail coach for a set period of time. Given that there is no significant manual aspect to the use of the rail coach height tool 20, 40, maintenance technicians suffer less fatigue, which increases both morale and productivity. The reduction in maintenance time and tool costs are also significant, with an average 50% reduction in the time required for tasks such as wheel 15 lathing. These and other embodiments of the present invention will be apparent to those skilled in the art and limited only by the scope of the appended claims.

Claims

1. Rail coach height tool, comprising:a support body adapted to be retained against at least one wall of an inspection pit, the inspection pit being an open three-sided elongate channel over which a rail coach is positioned;at least one powered lifting mechanism installed on the support body; anda height-adjustable platform mounted on the at least one powered lifting mechanism and adapted to align with a secondary suspension system present on the underside of a rail coach, wherein at least two compression pins are provided on the height-adjustable platform and adapted to engage with and compress a valve on an airbag present on the secondary suspension system of the rail coach.

2. Rail coach height tool as claimed in claim 1, wherein the support body is adapted to be retained between two of the sides of the inspection pit.

3. Rail coach height tool as claimed in claim 2, wherein the support body is further adapted to be engageable with, and movable along, the sides of the inspection pit.

4. Rail coach height tool as claimed in claim 1, wherein the support body is adapted to rest on, and be moveable along, a side of the inspection pit opposite its opening.

5. Rail coach height tool as claimed in claim 4, wherein the support body is mounted on wheels.

6. Rail coach height tool as claimed in any preceding claim, wherein the support body and the height-adjustable platform extend across the width of the inspection pit.

7. Rail coach height tool as claimed in any preceding claim, wherein the powered lifting mechanism comprises actuation means connected to a control located remotely from the rail coach height tool.

8. Rail coach height tool as claimed in any preceding claim, wherein the at least one powered lifting mechanism is hydraulic.

9. Rail coach height tool as claimed in claim 8, further comprising a remotely controlled compressed air supply connected to the powered lifting mechanism.

10. Rail coach height tool as claimed in any preceding claim, wherein the height-ad-justable platform is further adapted to hold the weight of the rail coach.

11. A method of supporting a rail coach over an inspection pit, comprising: positioning a rail coach height tool as claimed in any of claims 1 to 9 within an inspection pit underneath a secondary suspension system of the rail coach and securing the rail coach height tool in the position;isolating the compressors of the secondary suspension system;raising the height-adjustable platform until the at least two compression pins each contact a valve on an airbag in the secondary suspension system of the rail coach; and raising the height-adjustable platform and compressing the airbags until the rail coach rests on its primary suspension system alone.

12. A method of carrying out the maintenance of a rail coach supported over an inspection pit, comprising:positioning a rail coach height tool as claimed in any of claims 1 to 9 within an inspection pit underneath a secondary suspension system of the rail coach and securing the rail coach height tool in the position;isolating the compressors of the secondary suspension system;raising the height-adjustable platform until the at least two compression pins each contact a valve on an airbag in the secondary suspension system of the rail coach; and raising the height-adjustable platform and compressing the airbags until the rail coach rests on its primary suspension system alone;carrying out maintenance tasks; andwhen the maintenance tasks are complete, lowering the height-adjustable platform, decompressing the airbags and removing the support from the rail coach, moving the support from the rail coach.

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