Abstract: An improved in-track welder eliminates conduction path force members and employs separate bridging current path conductors for DC welding of rail ends. The enhancement allows for an increased closure distance, thus improving cold-weather operations. An increased allowable distance between conduction contacts allows for the incorporation of an internal shear member for more efficient finishing of welds. The force members may be optimized for strength rather than electrical properties, and are comprised of relatively small diameter alloy steel rods.

Abstract: An improved welding head for creating an in-track weld between a first rail segment and a second rail segment includes a controller having computer-readable instructions read by the controller. The computer-readable instructions include instructions for compensating for rail jerk during in-track welding. The welding head includes a closing force actuator, such as a hydraulic cylinder, for moving the rail segments toward one another. A pressure transducer is monitored during welding to determine a closing force. An impending jerk of the rail movement is detected if an abnormal closing force change is observed, and in response the flow of hydraulic fluid into or out of the hydraulic cylinder is restricted to prevent or minimize the jerk. In addition, when an impending jerk is detected the weld current may be temporarily increased to burn or prevent the formation of short circuit paths between the rails.

Abstract: An improved method for executing a flash butt weld to join first and second rail segments includes applying a voltage to the first rail segment and the second rail segment to establish a voltage difference between the first and second rail segments. The rail end faces are brought into contact, resulting in an electrical current between the first rail end face and the second rail end face, resistively heating material at the interface. As material burns off at the interface, the power consumed at the rail end interface as a function of rail displacement is periodically sampled. If the comparison indicates that the power per unit of rail displacement is not increasing from sample to sample, the burn-off process is terminated. In a further aspect, if the power per unit of rail displacement exceeds a predetermined threshold, the burn-off process is terminated.

Abstract: An improved method for executing a flash butt weld to join first and second rail segments includes applying a voltage to the first rail segment and the second rail segment to establish a voltage difference between the first and second rail segments. The rail end faces are brought into contact, resulting in an electrical current between the first rail end face and the second rail end face, resistively heating material at the interface. As material burns off at the interface, the power consumed at the rail end interface as a function of rail displacement is periodically sampled. If the comparison indicates that the power per unit of rail displacement is not increasing from sample to sample, the burn-off process is terminated. In a further aspect, if the power per unit of rail displacement exceeds a predetermined threshold, the burn-off process is terminated.

Abstract: An welding system is disclosed. The welding system may have a power supply, a forging arrangement configured to hold and move ends of two components to be welded together, and a plurality of contacts connecting the power supply to the two components. The welding system may also have a controller in communication with the power supply and the forging arrangement. The controller may be configured to regulate the power supply to selectively operate in a constant voltage mode and a constant current mode during different stages of a single weld cycle, and to actuate the forging arrangement to move the ends of the two components together during a final stage of the single weld cycle.

Abstract: An improved welding head for creating an in-track weld between a first rail segment and a second rail segment includes a controller having computer-readable instructions read by the controller. The computer-readable instructions include instructions for compensating for rail jerk during in-track welding. The welding head includes a closing force actuator, such as a hydraulic cylinder, for moving the rail segments toward one another. A pressure transducer is monitored during welding to determine a closing force. An impending jerk of the rail movement is detected if an abnormal closing force change is observed, and in response the flow of hydraulic fluid into or out of the hydraulic cylinder is restricted to prevent or minimize the jerk. In addition, when an impending jerk is detected the weld current may be temporarily increased to burn or prevent the formation of short circuit paths between the rails.

Abstract: An improved method for executing a flash butt weld to join first and second rail segments includes applying a voltage to the first rail segment and the second rail segment to establish a voltage difference between the first and second rail segments. The rail end faces are brought into contact, resulting in an electrical current between the first rail end face and the second rail end face, resistively heating material at the interface. As material burns off at the interface, the power consumed at the rail end interface as a function of rail displacement is periodically sampled. If the comparison indicates that the power per unit of rail displacement is not increasing from sample to sample, the burn-off process is terminated. In a further aspect, if the power per unit of rail displacement exceeds a predetermined threshold, the burn-off process is terminated.

Abstract: An improved in-track welder eliminates conduction path force members and employs separate bridging current path conductors for DC welding of rail ends. In an embodiment, this enhancement allows for an increased closure distance, thus improving cold-weather operations. In a further embodiment, an increased allowable distance between conduction contacts also allows for the incorporation of an internal shear member for more efficient finishing of welds. The force members may be optimized for strength rather than electrical properties, and in an embodiment are comprised of relatively small diameter alloy steel rods.

Abstract: A method and apparatus are provided for flash butt weld joining adjacent rail ends on site during initial field installation where at least one of the rails is fastened to the roadbed, and inclosure butt welding rails as in de-stressing long sections of rail track where both rails are fastened to the roadbed. The method and apparatus apply electrical power to the adjacent rail ends while simultaneously effecting relative closing movement between the rails ends through actuating means so as to bring the rail ends into position to effect current flow between the rail ends, and determining a force necessary to move the adjacent ends into a welding position under varying environmental conditions of the rails as the adjacent rail ends close and during flashing of the adjacent rail ends due to the current flow.

Abstract: A welding method and apparatus for flash butt welding adjacent ends of axially aligned railway rails includes a base frame and fixed and movable platens supported on the base frame. The platens support rail sections and are under the control of controller means operative to automatically move the movable platen through a predetermined distance/velocity relation as electrical power is inputted into the rail ends during straight flashing, preheating, flashing and upsetting phases of a welding cycle. The controller includes PID feedback loops operative to maintain the predetermined platen distance/velocity relation with entry of a single parameter by the operator. Significantly improved quality and repeatability of rail welds are obtained.