AUSTRALIA Patents Act COMPLETE SPECIFICATION (ORIGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Franz Plasser Bahnbaumaschinen-Industriegesellschaft m.b.H. Actual Inventor(s): Josef Theurer, Bernhard Lichtberger Address for Service and Correspondence: PHILLIPS ORMONDE & FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: A METHOD OF REMOVING DAMAGED RAIL SECTIONS OF A TRACK, AND A MACHINE Our Ref : 763431 POF Code: 1203/1203 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6008q 2 A METHOD OF REMOVING DAMAGED RAIL SECTIONS OF A TRACK This application claims priority from Austrian Application No. A 533/2005 filed 30 March 2005, the contents of which are incorporated herein by this reference. The invention relates to a method of removing damaged rail sections according 5 to the features cited in the introductory part of claim 1. Numerous methods or devices for welding rail ends together are disclosed in US 4 929 816, GB 0 326 794, US 4 983 801 and US 6 515 249. US 5 469 791 discloses transportation of rails to the installation site by means of a special machine. A rail pulling device and a welding unit are furnished by a 10 second and third machine. It is the object of the present invention to provide a method of the specified kind with which it is possible to execute in an efficient manner also a greater number of welds for achieving a desired rail tension. According to the invention, this object is achieved with a method of the specified 15 kind by means of the features cited in the characterizing part of claim 1. With these features of the method, it is possible to determine a difference between an actual rail tension and a desired rail tension in connection with a removal of a damaged rail section. Taking into account the found difference, it is possible to accurately establish the required length of the rail section to be 20 removed in accordance with the length of the replacement section. The prepared replacement rail of accurate length enables a quick execution of the two required welding operations, achieving a desired rail tension. In an <Ilename> 3 advantageous manner, both the removal of the damaged rail sections and the providing of replacement rails of accurately defined length can take place entirely independent of the welding process. With this, it is possible to carry out with optimal efficiency both the welding preparation and the welding itself. 5 Additional advantages of the invention become apparent from the further claims and the description of the drawing. The invention will be described in more detail below with reference to an embodiment represented in the drawing in which Fig. 1 is a side view of a machine arrangement for preparation of a rail weld, 10 Fig. 2 is a top view of a rail pulling device for pulling two rail ends together, and Figs. 3 to 15 are respective schematic side views of the machine arrangement during various stages of a method according to a preferred embodiment of the invention. A machine arrangement 1, visible in Fig. 1, is composed of a first machine 2, a 15 second machine 4 detachably connected to the former by means of a coupling 3, and a third machine 5 designed to be transported by the second machine 4 during transfer travel. Each of said machines 2,4,5 comprises a machine frame 8 mobile by means of on-track undercarriages 6 on a track 7, and each is equipped with a motive drive 9. 20 The first machine 2 comprises a rail storage facility 13 located between a driver's cabin 10 and a crane jib 12, the latter being vertically adjustable <rijename> 4 and rotatable by drives 11. The rail storage facility 13 is configured for transporting and storing a number of replacement rails 14 of different length. Provided underneath the machine frame 8, between the two on track undercarriages 6 placed at the ends, is a saw guide 16 extending in a longitudinal direction 15 of the machine, on which a rail cutting saw 17 is mounted for displacement by means of a drive 18. A path travelled due to the displacement of the rail cutting saw 17 is registered by an odometer 41. Connected to the machine frame 8 in immediate proximity to each on track undercarriage 6 is a respective pair 21 of lifting rams 22 which can be lowered upon the track 7 by means of a drive 23. [0017] A rail pulling device 20, fastened to the machine frame 8 for vertical adjustment by drives 19, is designed for gripping two rail ends 24 of a rail 25 of the track 7 (see Fig. 2). Devices 26 are provided for driving or pulling rail spikes. A vertically adjustable grinding device 27 serves for grinding rail web portions. [0018] The second machine 4 is equipped with a vertically adjustable device 28 for detaching rail anchors, and a rotatable roller 29 for detaching base plates adhering to the rail 25. Provided in front of the front on-track undercarriage 6 is a vertically adjustable transport device 30 by which the third machine 5 can be transported on the way to the track construction site. Said third machine 5 is also equipped with a device 28 for detaching rail anchors.
5 [0019] The rail pulling device 20, shown in more detail in Fig. 2, comprises two pairs 31 of rail clamps 32 designed for gripping the two rail ends 24, the pairs being spaced from one another in the longitudinal direction 15 of the machine. The rail ends 24 can be pulled towards one another by actuation of two drives 33. A force f required to do so can be registered by means of a force measuring device 34. A temperature measuring device 35 is provided for detecting an actual rail temperature. Said device, as well as the force measuring device 34, is connected via lines 36 to a control- and computing unit 38 having a storage medium 37. Stored in the storage medium 37 are the various lengths of the replacement rails 14, kept in stock on the rail storage facility 13, and also a respective identification feature. An odometer 40 is provided for measuring a rail gap 39 defined by the distance of the two rail ends 24 to one another. [0020] The method of removing damaged rail sections 42 and of welding preparation will now be described in more detail in connection with the further Figs. 3 to 15, wherein a dash-and-dot line indicates the local installation site 43 in the track 7, remaining unchanged in Figs. 3 to 15 and defined by the rail section 42 to be removed. [0021] The machine arrangement 1 is moved in the direction represented by an arrow 44 and stopped in front of the installation site 43 (see Fig. 3). After setting the third machine 5 down upon the track 7 (Fig. 4), the sleeper anchors - lying to the left of the installation site 43 in the drawing - are 6 detached with the aid of the device 28 until the machine 5 has reached an end position visible in Fig. 5. [0022] Parallel to this, the second machine 4 is moved in the direction towards the installation site 43, during which the sleeper anchors - positioned to the right of the installation site 43 in the picture plane - are detached by means of the corresponding device 28 (Fig. 6). The length of those rail portions in which the rail anchors are detached is registered by an odometer wheel and transmitted by radio to the control- and computing unit 38. In the region of said rail portions, the rail spikes are also removed or loosened. With the aid of the lowered roller 29, the base plates are detached from the rail base of the rails which are lifted slightly from the sleepers. [0023] The first machine 2 is moved to the installation site 43, and that point on the rail 25 is marked on which a first separating cut is to take place (Fig. 7). [0024] In further sequence, as shown in Fig. 8, the rail cutting saw 17 is positioned above the marked point , and the first separating cut is carried out, resulting in the two rail ends 21 being spaced from one another, thus forming a rail gap 39 (see Fig. 2). Rotatable wire brushes 45 mounted displaceably on the machine frame 8 are pressed against a rail web of the two rail ends 24 in order to optimize the contact points intended for the welding unit. An on-track undercarriage 6 positioned at one end of the first 7 machine 2 is raised slightly from the track 7 by lowering the associated lifting rams 22. [0025] The rail pulling device 20 is placed upon the two rail ends 21 (Fig. 9 and 2) in order to pull the same towards one another with actuation of the two drives 33 until the rail gap 39 has been eliminated. The force f necessary to do so is registered by the force measuring device 34 and recorded. In order to positively preclude an incorrect force measurement which might be caused by the rails becoming wedged, the two rail ends are pulled together repeatedly until the rail portions delimited by the removal of the rail spikes are in a tension-free state. Parallel to that, the actual rail temperature is measured with the aid of the temperature measuring device 35, and the length I of the rail gap is measured by the odometer device 40. In the meantime, the second and third machines 4,5 have been moved on to the next damaged rail section in order to detach the rail anchors over the required distance. [0026] On the basis of the measuring values passed on to the control- and computing unit 38, and the lengths - stored in the storage medium 37 - of the replacement rails 14 which are in stock and have already been prepared for optimal welding, the best-suited replacement rail 14 is calculated automatically. The rail cutting saw 17 is displaced forward on the saw guide 16 in the working direction 44, or in the longitudinal direction of the machine, with the displacement path of the saw being measured, 8 until the length computed by the control- and computing unit 38 for the rail section 42 to be removed has been reached. Said length was calculated while taking into account the length of the selected replacement rail 14 as well as the difference between the actual rail temperature and a stored neutral temperature. Also to be taken into account with regard to the required length of the replacement rail 14 is the burning-off occurring due to the double flash-butt welding, as well as the reduction of rail length after the upset impact, in order to finally obtain a desired rail tension despite these length reductions after welding of the replacement rail 14. After a second separating cut (Fig. 10) by means of the rail cutting saw 17 and the removal of the rail spikes, the severed damaged rail section 42 is removed. It is also possible, of course, to cut off a piece of suitable length from a longer replacement rail 14, particularly if a suitable replacement rail 14 is not on hand. [0027] With the aid of the crane jib 12, the replacement rail 14 selected by the control- and computing unit 38 is set down upon the track 7, with one end being positioned adjoining a rail end 24 (Figs. 11,12). The second end of the replacement rail 14 is arranged overlapping the second rail end 24, if necessary - in dependence upon the difference between the actual and neutral temperatures. To secure the position of the replacement rail 14 placed on the track 7, the corresponding rail spikes are driven into the sleepers (Fig. 13).
9 [0028] As can be seen in Fig. 14, the first machine 2 - after lowering the raised on-track undercarriage 6 - is moved forward in the working direction 44 until it is possible to work on the rail ends 24 with the rail grinding device 27. Subsequently (Fig. 15), the machine 2 moves on to the next installation site 43, where the described working steps are repeated. [0029] The two welds for welding the replacement rail 14 are executed by means of a following welding machine, not shown, using the flash-butt welding method, wherein the relevant measuring data are passed on by radio or disc from the controlling and computing unit 38 to a control unit of the welding machine.