with the profile of the corresponding wheel guide and thus obtaining a greater contact surface to increase friction coefficients the wheels are attached by means of grooved axles 24 and gears 26 also shown in fig9 these connect all the wheels 22 the front wheels are joined together and the rear wheels are also linked together so that all work and brake as a whole all these wheels 22 are joined to an articulated sub chassis 20 by the axles 24 that pass through from one side to the other of the assembly there are two types of axles 23 y 24 the fluting or grooved axles 24 join the wheels and gears to the sub chassis 20 and the latter to the main chassis the axles 23 have smooth surfaces and allow for the rotation of articulated gears and for the rotation of the turning corrector the turning corrector provides for the articulation of the sub chassis 20 between two wheels 22 and acts as a support for the connecting coupling gear between each one of the wheel 39 s gear 26 the turning corrector not only allows for the simultaneous rotation of the wheels but it also allows the rotation of the articulation of the sub chassis 20 the axle 24 has a double function the first function is to attach the wheels 22 to the articulated sub.