US Patent 6909068 All-terrain undercarriage

A moveable undercarriage for supporting and moving a welder over a ground surface having a base to support the welder, a front and rear axle secured to the base each having two wheels rotatably secured to the axles, and a push bar secured to said base to move the base over a ground surface. The front and rear axles are positioned on the base such that the center of gravity of the welder lies between the axles. The front and rear axles are spaced apart a distance that is less than three times the sum of the radii of the front and rear wheels. The undercarriage includes a brake to engage at least one wheel in a locked position. The push bar has a lift bar to facilitate in the moving of the base.