Self-lubricating mechanical friction parts, especially of composite materials, namely, wear rings, washers, bushings, spherical bearings, bearing pads, sliding blocks and machine transmission gears all for load bearing machines, conveyors, handling trucks and machines, lifting machines, agricultural machinery, construction equipment machines and hydraulic turbines

MOTOR VEHICLES SUPPORTED BY AIR CUSHION DEVICES FOR PROPULSION OVER RAILS, TRACKS OR GUIDEWAYS FOR CARRYING PASSENGERS OR CARGO, AND AIR CUSHION DEVICES FOR SUCH VEHICLES