NZ730986A - Rail Weld Shearing Machine - Google Patents

Abstract

The present invention relates broadly to a rail weld shearing machine 10 comprising a vehicle 12, and a weld shear head 14 coupled to the vehicle 12 via its boom 16 and an associated arm 17. The vehicle 12 includes a power source 18 in the form of a hydraulic power source operatively coupled to the weld shear head 14. The weld shear head 14 includes a pair of shear cutters 20A and 20B powered by the hydraulic power source 18 for actuation of the shear cutters 20A/B for shearing excess weld deposit from an associated rail weld. weld shear head 14. The weld shear head 14 includes a pair of shear cutters 20A and 20B powered by the hydraulic power source 18 for actuation of the shear cutters 20A/B for shearing excess weld deposit from an associated rail weld.

Description

RAIL WELD SHEARING MACHINE Technical Field The present invention relates broadly to a rail weld shearing machine.

Summary of Invention According to one aspect of the present invention there is provided a rail weld shearing machine comprising: a vehicle including a power source and a boom; a weld shear head coupled to the boom and operatively coupled to the power source, the weld shear head including at least one shear cutter powered by the power source whereby location of the weld shear head proximal a rail weld is provided by movement of the boom whereupon shearing of excess weld deposit from the rail weld is effected by actuation of the shear cutter via the power source at the vehicle.

According to another aspect of the invention there is provided a rail weld shearing assembly comprising: a weld shear head adapted to be detachably coupled to a vehicle including a power source; a weld shear cutter mounted to the weld shear head and powered by the power source whereby shearing of excess weld deposit from a rail weld is effected by location of the weld shear head proximal a rail weld and actuation of the weld shear cutter via the power source at the vehicle.

Preferably the weld shear head includes a framework to which a pair of the shear cutters are mounted, the framework detachably coupled to an end of the boom distal from the vehicle. More preferably the framework includes a drive mounting to which one of the pair of shear cutters is secured, and a driven mounting to which the other of the pair of shear cutters is mounted. Even more preferably the driven mounting is displaced relative to the drive mounting via drive means mounted to the drive mounting and operatively powered by the power source whereby said relative displacement effects shearing of the excess weld deposit from the rail weld.

Preferably the drive means includes at least one hydraulically-actuated cylinder including a cylinder barrel mounted to the drive mounting, and a piston rod mounted to the driven mounting. More preferably the power source is a hydraulic power source which powers the hydraulically-actuated cylinder for the relative displacement of the drive and driven mountings for shearing of the excess weld deposit via the pair of shear cutters. Even more preferably the hydraulically-actuated cylinder is one of a pair of said cylinders configured to operate in concert for shearing of the excess weld deposit.

Preferably the drive mounting includes an inner mounting plate to which an inner of the shear cutters is secured, the cylinder barrel of each of the hydraulically- actuated cylinders being mounted to the inner mounting plate on either side of the inner shear cutter. More preferably the driven mounting includes an outer mounting plate to which an outer of the shear cutters is secured, the piston rod of each of the hydraulically-actuated cylinders being fixed to the outer mounting plate on either side of the outer shear cutter whereby the relative displacement of the drive and driven mountings via the pair of hydraulically-actuated cylinders effects shearing of the excess weld deposit.

Preferably the hydraulically-actuated cylinder includes a high temperature seal arrangement between the inner and outer mounting plates, said seal arrangement designed to provide adequate sealing between the piston rod and an exposed end portion of the cylinder barrel whilst withstanding relatively high temperatures to which it is exposed from the excess weld deposit. More preferably said seal arrangement includes a pair of high temperature annular seals spaced along and housed within the exposed end portion of the cylinder barrel.

Preferably the hydraulic power source is a hydraulic pump mounted to the vehicle for delivering pressurised hydraulic fluid to the hydraulically-actuated cylinder via one or more hydraulic fluid lines. More preferably the hydraulic pump is driven by a petrol or diesel-fuelled engine. Even more preferably said engine includes a catalytic convertor designed to clean emissions from the engine. Still more preferably the hydraulic fluid lines are mounted to the boom.

Preferably the vehicle is an excavator and more preferably a rail mounted excavator.

Brief Description of Drawings In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a rail weld shearing machine will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of a rail weld shearing machine according to the invention; Figure 2 is a perspective view of the rail weld shearing machine of the preferred embodiment of figure 1 in operation; Figure 3 is an enlarged perspective view of a rail weld shear head of the rail weld shearing machine taken from figure 2.

Detailed Description As shown in figures 1 and 2 there is a rail weld shearing machine 10 comprising a vehicle 12 in the form of a rail mounted excavator, and a weld shear head 14 coupled to the excavator 12 via its boom 16 and an associated arm 17. The excavator 12 includes a power source 18 in the form of a hydraulic power source operatively coupled to the weld shear head 14. The weld shear head 14 includes a pair of shear cutters 20A and 20B powered by the hydraulic power source 18 for actuation of the shear cutters 20A/B for shearing excess weld deposit from an associated rail weld.

In this embodiment the weld shear head 14 is coupled to a conventional hitching arrangement 22 mounted to a distal end of the arm 17. The excavator 12 together with the boom 16, the arm 17, and its associated hitching arrangement 22 allows location of the weld shear head 14 proximal the rail weld to be sheared. The rail weld may be located on one of the pair of rails 24A and 24B on which the excavator 12 is mounted. Alternatively as shown in figure 2 the rail weld 26a is located on a rail 26A alongside the rail mounted excavator 12. The weld shear head 14 is in this instance swivelled about the arm 17 and hitching arrangement 22 so that it generally aligns with the associated rail 26A.

As best illustrated in figure 3 the weld shear head 14 includes a framework 28 to which the pair of shear cutters 20A/B are mounted. The framework 28 broadly includes a drive mounting 30 to which one of the shear cutters 20B is secured, and a driven mounting 32 to which the other of the shear cutters 20A is secured. The drive mounting 30 also provides detachable coupling of the weld shear head 14 to the arm 17 via the hitching arrangement 22. In operation the driven mounting 32 and its associated shear 20A is displaced relative to the drive mounting 30 and its associated shear cutter 20B via drive means 34 mounted to the drive mounting 30. The drive means 34 in this embodiment includes a pair of hydraulically-actuated cylinders 36A and 36B powered by the hydraulic power source 18 of the excavator 12. The pair of hydraulically-actuated cylinders 36A/B operate in concert for shearing of the excess weld deposit.

The drive mounting 30 includes an inner mounting plate 38 to which the inner shear cutter 20B is secured, and a bracket support 40 for coupling to the hitching arrangement 22. The driven mounting 32 includes an outer mounting plate 42 to which the outer shear cutter 20A is secured. The pair of hydraulically-actuated cylinders 36A/B are disposed either side of the shear cutters 20A/B which are generally aligned.

Each of the hydraulically-actuated cylinders such as 36A includes a cylinder barrel 44A flange mounted to the inner mounting plate 38 and a piston rod 46A flange mounted to the outer mounting plate 42. The pair of hydraulically-actuated cylinders 36A/B are thus activated to provide the relative displacement of the drive 30 and driven mountings 32 to effect shearing of the excess weld deposit.

The hydraulic power source 18 of this embodiment includes a hydraulic pump (not shown) mounted to the excavator 12 for delivering pressurised hydraulic fluid to the hydraulically-actuated cylinders 36A/B via one or more hydraulic fluid lines such as 50A. The hydraulic fluid lines such as 50A are mounted to the excavator boom 16 and arm 17 and interconnect the hydraulic pump at the excavator 12 with the hydraulically-actuated cylinders 36A/B at the weld shear head 14. In this exampled the hydraulic pump is driven by a petrol or diesel-fuelled engine at the excavator 12. The engine may include a catalytic converter (not shown) designed to clean emissions from the engine to reduce toxic pollutants in a conventional manner.

In joining rails thermite welding is widely used. Thermite welding is an exothermic welding process that employs molten metal at high temperature. The weld shear head 14 of this embodiment of the invention is specifically designed to operate in this high temperature environment. In particular, the weld shear head 14 includes: 1. a high temperature seal arrangement such as 52A for each of the hydraulically- actuated cylinders such as 36A in the vicinity of the excess weld deposit of the thermite rail weld; 2. isolation of the hydraulic fluid lines such as 50A distant from the thermite weld, typically shielded by the drive support structure 30.

The high temperature seal arrangement such as 52A includes a pair of high temperature annular seals (not shown) spaced along and housed within an end portion 54A of the cylinder barrel such as 44A. The hydraulically-actuated cylinders such as 36A operate at relatively high hydraulic fluid pressures expected to approach 4,500 psi on shearing on the excess weld deposit. The cylinders 36A/B and their associated seal arrangement 52A and hydraulic fluid lines 50A are specifically designed to tolerate the high temperature of the thermite weld environment and the high pressure of the hydraulic fluid.

The general steps involved in operation of this embodiment of the rail weld shearing machine 10 are as follows: 1. an operator located within the rail mounted excavator 12 manoeuvres the boom 16 and arm 17 to position the weld shear head 14 proximal the rail weld such as 26a with excess weld deposit (see figure 2); 2. the weld shear head 14 with its pair of weld shear cutters 20A/B separated locates or nests upon the rail 26A either side of the rail weld 26a (see figure 3); 3. the operator actuates the hydraulically-actuated cylinders 36A/B at the excavator 12 via the hydraulic power source 18 to effect relative displacement and closure of the shear cutters 20A/B for shearing of the excess weld deposit in an initial cutting action; 4. the operator may repeat shearing of the excess weld deposit by opening and closing the shear cutters 20A/B by repeated activation of the hydraulic power source 18 at the excavator 12 until an effective shearing of the excess weld deposit is achieved.

This shearing operation must be performed in a relatively short timeframe prior to hardening of the molten thermite weld, for example within 30 to 45 seconds.

On completion of shearing of the excess weld deposit, the weld shear head 14 is lifted clear of the rail 26A via the boom 16 and arm 17 of the excavator 12. The sheared excess weld deposit is then in its cooled and solid state removed from the rail 26A by manually operated tools, such as a pinch bar.

Now that a preferred embodiment of a rail weld shearing machine has been described it will be apparent to those skilled in the art that it has the following advantages: 1. it avoids the requirement for multiple operators to physically lift a conventional weld shear onto the rail risking physical injury to the operator through musculoskeletal injury or molten metal burns; 2. it eliminates the risk of injury to an operator from hydraulic fluid line failures which can occur with conventional rail weld shears exposed to the excessive heat of the thermite weld; 3. the shearing machine can be operated in confined spaces or underground which is not possible with conventional rail weld shears due to the fumes associated with petrol or diesel power packs; 4. the weld shear head is efficient in shearing the complete weld profile in a relatively short space of time whilst the thermite weld is still largely molten.

Those skilled in the art will appreciate that the invention as described herein is susceptible to variations and modifications other than those specifically described.

For example, the hydraulically-actuated cylinders may be replaced with a mechanical arrangement which provides the relative displacement between the pair of shear cutters for shearing of the excess weld deposit. The excavator may take the form of another vehicle which includes an appropriate power source to power drive means located at the weld shear head for cutting of excess weld deposit via a pair of shear cutters. All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

Claims (31)

Claims 1.

1. A rail weld shearing machine comprising: a vehicle including a power source and a boom; a weld shear head coupled to the boom and operatively coupled to the power source, the weld shear head including at least one shear cutter powered by the power source whereby location of the weld shear head proximal a rail weld is provided by movement of the boom whereupon shearing of excess weld deposit from the rail weld is effected by actuation of the shear cutter via the power source at the vehicle.

2. A rail weld shearing machine as defined in claim 1 wherein the weld shear head includes a framework to which a pair of the shear cutters are mounted, the framework detachably coupled to an end of the boom distal from the vehicle.

3. A rail weld shearing machine as defined in claim 2 wherein the framework includes a drive mounting to which one of the pair of shear cutters is secured, and a driven mounting to which the other of the pair of shear cutters is mounted.

4. A rail weld shearing machine as defined in claim 3 wherein the driven mounting is displaced relative to the drive mounting via drive means mounted to the drive mounting and operatively powered by the power source whereby said relative displacement effects shearing of the excess weld deposit from the rail weld.

5. A rail weld shearing machine as defined in claim 4 wherein the drive means includes at least one hydraulically-actuated cylinder including a cylinder barrel mounted to the drive mounting, and a piston rod mounted to the driven mounting.

6. A rail weld shearing machine as defined in claim 5 wherein the power source is a hydraulic power source which powers the hydraulically-actuated cylinder for the relative displacement of the drive and driven mountings for shearing of the excess weld deposit via the pair of shear cutters.

7. A rail weld shearing machine as defined in either of claims 5 or 6 wherein the hydraulically-actuated cylinder is one of a pair of said cylinders configured to operate in concert for shearing of the excess weld deposit.

8. A rail weld shearing machine as defined in claim 7 wherein the drive mounting includes an inner mounting plate to which an inner of the shear cutters is secured, the cylinder barrel of each of the hydraulically-actuated cylinders being mounted to the inner mounting plate on either side of the inner shear cutter.

9. A rail weld shearing machine as defined in claim 8 wherein the driven mounting includes an outer mounting plate to which an outer of the shear cutters is secured, the piston rod of each of the hydraulically-actuated cylinders being fixed to the outer mounting plate on either side of the outer shear cutter whereby the relative displacement of the drive and driven mountings via the pair of hydraulically-actuated cylinders effects shearing of the excess weld deposit.

10. A rail weld shearing machine as defined in claim 9 wherein the hydraulically- actuated cylinder includes a high temperature seal arrangement between the inner and outer mounting plates, said seal arrangement designed to provide adequate sealing between the piston rod and an exposed end portion of the cylinder barrel whilst withstanding relatively high temperatures to which it is exposed from the excess weld deposit.

11. A rail weld shearing machine as defined in claim 10 wherein said seal arrangement includes a pair of high temperature annular seals spaced along and housed within the exposed end portion of the cylinder barrel.

12. A rail weld shearing machine as defined in any one of claims 6 to 11 wherein the hydraulic power source is a hydraulic pump mounted to the vehicle for delivering pressurised hydraulic fluid to the hydraulically-actuated cylinder via one or more hydraulic fluid lines.

13. A rail weld shearing machine as defined in claim 12 wherein the hydraulic pump is driven by a petrol or diesel-fuelled engine.

14. A rail weld shearing machine as defined in claim 13 wherein said engine includes a catalytic convertor designed to clean emissions from the engine.

15. A rail weld shearing machine as defined in any one of claims 12 to 14 wherein the hydraulic fluid lines are mounted to the boom.

16. A rail weld shearing machine as defined in any one of the preceding claims wherein the vehicle is an excavator.

17. A rail weld shearing assembly comprising: a weld shear head adapted to be detachably coupled to a vehicle including a power source; a weld shear cutter mounted to the weld shear head and powered by the power source whereby shearing of excess weld deposit from a rail weld is effected by location of the weld shear head proximal a rail weld and actuation of the weld shear cutter via the power source at the vehicle.

18. A rail weld shearing assembly as defined in claim 17 wherein the weld shear head includes a framework to which a pair of the shear cutters are mounted, the framework detachably coupled to an end of the boom distal from the vehicle.

19. A rail weld shearing assembly as defined in claim 18 wherein the framework includes a drive mounting to which one of the pair of shear cutters is secured, and a driven mounting to which the other of the pair of shear cutters is mounted.

20. A rail weld shearing assembly as defined in claim 19 wherein the driven mounting is displaced relative to the drive mounting via drive means mounted to the drive mounting and operatively powered by the power source whereby said relative displacement effects shearing of the excess weld deposit from the rail weld.

21. A rail weld shearing assembly as defined in claim 20 wherein the drive means includes at least one hydraulically-actuated cylinder including a cylinder barrel mounted to the drive mounting, and a piston rod mounted to the driven mounting.

22. A rail weld shearing assembly as defined in claim 21 wherein the power source is a hydraulic power source which powers the hydraulically-actuated cylinder for the relative displacement of the drive and driven mountings for shearing of the excess weld deposit via the pair of shear cutters.

23. A rail weld shearing assembly as defined in either of claims 21 or 22 wherein the hydraulically-actuated cylinder is one of a pair of said cylinders configured to operate in concert for shearing of the excess weld deposit.

24. A rail weld shearing assembly as defined in claim 23 wherein the drive mounting includes an inner mounting plate to which an inner of the shear cutters is secured, the cylinder barrel of each of the hydraulically-actuated cylinders being mounted to the inner mounting plate on either side of the inner shear cutter.

25. A rail weld shearing assembly as defined in claim 24 wherein the driven mounting includes an outer mounting plate to which an outer of the shear cutters is secured, the piston rod of each of the hydraulically-actuated cylinders being fixed to the outer mounting plate on either side of the outer shear cutter whereby the relative displacement of the drive and driven mountings via the pair of hydraulically-actuated cylinders effects shearing of the excess weld deposit.

26. A rail weld shearing assembly as defined in claim 25 wherein the hydraulically- actuated cylinder includes a high temperature seal arrangement between the inner and outer mounting plates, said seal arrangement designed to provide adequate sealing between the piston rod and an exposed end portion of the cylinder barrel whilst withstanding relatively high temperatures to which it is exposed from the excess weld deposit.

27. A rail weld shearing assembly as defined in claim 26 wherein said seal arrangement includes a pair of high temperature annular seals spaced along and housed within the exposed end portion of the cylinder barrel.

28. A rail weld shearing assembly as defined in any one of claims 22 to 27 wherein the hydraulic power source is a hydraulic pump mounted to the vehicle for delivering pressurised hydraulic fluid to the hydraulically-actuated cylinder via one or more hydraulic fluid lines.

29. A rail weld shearing assembly as defined in claim 28 wherein the hydraulic pump is driven by a petrol or diesel-fuelled engine.

30. A rail weld shearing assembly as defined in claim 29 wherein said engine includes a catalytic convertor designed to clean emissions from the engine.

31. A rail weld shearing assembly as defined in claims 17 to 30 the vehicle is an excavator and more preferably a rail mounted excavator.