Air film pallet

Claim 1

A vehicle comprising, a frame having a rear control section and a forward bi-furcated platform section, said platform section having a top loadreceiving platform surface and a bottom ground support surface interrupted by cavities, front guide wheel means and a rear caster wheel means housed in respective said cavities and each spring-biased to move downwardly to a wheel support plane slightly below said ground support surface and to there collectively support the vehicle when the platform is not loaded, air bearings housed in respective said cavities and arranged when inflated to expand below said wheel support plane and support the vehicle on respective air films defining an air film support plane below said wheel support plane, first air spring means in said cavities for further urging said front guide wheels downwardly into ground engagement when the vehicle is supported by said air bearings, a vertically movable rear steerable traction wheel means housed in said control section and located rearwardly of said caster wheel means, spring means urging said traction wheel means into an inactive position above said ground support surface, second air spring means opposing the latter spring means for selectively moving said traction wheel into ground engagement when the vehicle is supported by the air bearings when loaded or by the guide wheel and caster wheel means when not loaded, an operator station on said control section and behind said traction wheel means, and control means operable at the operator station for selectively inflating said air bearings and first and second air spring means and for operating the traction wheel means, the spring-biasing of said guide wheel means and caster wheel means being such as to yield in an emergency with the platform loaded to thereby permit the vehicle to settle down to its said bottom ground support surface.