Patent ID: 7253380

Claim:
A self contained system for preheating and welding a gap in a railroad rail comprising: a weld delivery apparatus and power supply; a tool having first and second opposing sides, and disposed in a gap defined by first and second facing ends of the gap in the railroad rail, the tool further including mechanical centering assemblies disposed adjacent the facing ends of the gap in the railroad rail, wherein the mechanical centering assemblies position the tool longitudinally with respect to the railroad rails for proper proximity to the gap in the railroad rail; a first induction heating element affixed to the first side of the tool and disposed proximate the first and second railroad rails; a first heating zone defined by a first temperature sensor positioned proximate the first end of the gap in the railroad rail and the first heating element; a second induction heating element affixed to the second side of the tool and disposed proximate the first and second ends; a second heating zone defined by a second temperature sensor positioned proximate the second end of the gap in the railroad rail and the second heating element; a controller coupled to the first and second temperature sensors, the controller activating the first and second heating elements independently to achieve a preheating welding temperature in both first and second heating zones, said preheating temperature being controlled to be less than the melting point of the rail; and welding means for welding the railroad rails by filling the gap with weld material; said welding means comprising arc welding in which the energy used in welding can be sensed thereby providing feedback to said controller; said controller using said feedback to adjust said first temperature and said second temperature; said power supply providing energy for continuous operation of said first and second heating elements and welding means.