Patent Application
20140096698
The present invention relates to methods and apparatus for stabilizing railway rails during railway repairs. More specifically, the present invention relates to methods and apparatus for maintaining the position of railway rails relative to one another and to an underlying structure while rail ties are being replaced, particularly on railway bridges.
Replacement of rail ties is among the most common railroad or railway repairs. It is time- and labor-consuming and if not carefully carried out, runs the risk of damaging the track by moving the rails “out of gage” (too far apart or close together), out of parallel alignment relative to one another and to the rail bed, or bending the rails. Automated equipment exists for replacing rail ties that uses jigs and fixtures to stabilize the rails while old ties are removed and new ties driven in.
Replacement of rail ties is particularly challenging on railway bridges or trestles because the bridge is often the only solid surrounding structure on which workers and equipment can stand. It is expensive and time-consuming to bring in large work gangs and bridge work is a special operation due to its additional safety (fall protection) and structural requirements. n these operations, the need for rail stabilization is particularly acute.
A need exists, therefore, for methods and apparatus for stabilizing railroad track during tie-replacement operations or other rail repair work.
It is a general object of the present invention to provide a method and apparatus for stabilizing railroad rails during tie replacement on a working bridge or trestle. This and other objects of the present invention are achieved with a stabilizer for use in stabilizing and maintaining the spacing between a pair of railway rails during rail tie replacement. The stabilizer comprises a rod having a length and a pair of ends. A pair of rail clamps is carried by the rod, and each clamp is configured to engage one of the rails and secure the rail relative to the rod. An expanding member is carried by the rod and configured to selectively expand along the length of the rod between its ends to engage a structure proximal to the rails, wherein, upon engagement of the rails by the rail clamps and the expanding member with the structure, the rails are maintained in substantially fixed relationship to each other and to the structure, but are free to be moved vertically relative to the structure.
According to one embodiment of the present invention, the expanding member further comprises a pair of shoes carried by the rod and movable along the length of the rod, each shoe extending transversely from the rod. A scissor mechanism is arranged between the pair of shoes to selectively move the shoes toward and apart from one another.
According to one embodiment of the present invention, the structure is a railway bridge and the shoes engage portions of the railway bridge below the rails.
A method of stabilizing a pair of railway rails on a rail bridge is also disclosed and comprises the steps of maintaining the railway rails at a fixed distance from one another by engaging them with a rod of fixed length corresponding to the fixed distance. Next, the rails are secured in a fixed position relative to the railway bridge by abutting a portion of the railway bridge with an expanding structure rigidly coupled to the rod. Finally, the rails are raised vertically relative to the railway bridge to permit ties to be removed and replaced.
According to one embodiment of the present invention, the engaging step further comprises clamping one end of the rod to each of the pair of railway rails.
According to one embodiment of the present invention, the abutting step further comprises expanding the structure rigidly coupled to the rod into abutment with a portion of the railway bridge below the rails.
Referring now to the Figures and particularly to
A pair of shoes 17 may be slidably mounted at their upper ends to gage rod 13. Shoes 17 are movable along the length of gage rod 13 between expanded and collapsed positions and may be mounted to rod 13 using linear bearings and clevis pins for smooth operation and easy disassembly. A scissor mechanism 19 may be arranged between shoes 17 to move them between the expanded and collapsed position. Scissor mechanism 19 preferably is a four link mechanism with each link of equal length and pinned at its ends and middle (there are preferably two identical scissor mechanisms on each side of shoes 17, which doubles the number of links for strength but does not change the mechanical properties of the mechanism). A removable handle 23 may be attached to screw 21 to lift stabilizer 11 and the rails clamped to it for rail tie replacement.
Scissor mechanism 19 may be actuated by turning a lead screw 21, which is coupled to the center joints of the mechanism by nuts. Thus, rotation of lead screw 21 expands and contracts scissors 19 and, in turn, shoes 17. An L-shaped stop 17A is located on each shoe 17 just below gage rod 13 to prevent structures from contacting and damaging rod 13. According to a preferred embodiment of the invention, in the expanded or fully open position, shoes 17 are 28.13 inches apart (measured at outer edge), and in the contracted or fully closed position, shoes 17 are 9.88 inches apart. Mechanisms other than scissors may be useful to expand and contract shoes 17.
In operation, stabilizer 11 is placed on the rail bed with clamps 15 adjacent each rail. Clamps 15 then are engaged with and secured to the rails with shoes 17 extending downwardly between the support structure underneath the rail bed, which is usually a pair of spaced-apart wooden, concrete, or steel beams. Screw 21 may then be rotated to expand scissor mechanism 19 and shoes 17, until they are firmly engaged with and abutting the support structure. At that point, gage rod 13 and clamps 15 maintain the rails in their spaced-apart relationship at a distance corresponding to the railroad gage. Engagement and abutment between shoes 17 and the support structure maintains the rails in a fixed lateral relationship relative to the rail bed (avoiding lateral movement and potential bending). However, stabilizer 11 and the rails secured to it are free to move vertically relative to the railway bridge or rail bed, allowing them to be lifted. With the rails so stabilized, the rails may be lifted using grab hook 23 and stabilizer 11 as a lift point. The rail ties can be driven out and replaced. In most cases, several stabilizers 11 are used along the length of the bridge or trestle to stabilize the rails at multiple points along their length.
The stabilizer according to the present invention offers the ability to stabilize railroad rails during rail tie replacement and other operations on bridges and trestles. The stabilizer may be placed while the track remains in operation, permitting later use to remove and replace ties.
The invention has been described with reference to preferred embodiments thereof, it is thus not limited, but is susceptible to variation and modification without departing from the scope and spirit of the invention.
